The rabbit cornea lacks cholinergic receptors. Cholinergic receptors were studied in membranes prepared from rabbit cornea, iris-ciliary body, and retina, using 3H-quinuclidinyl benzilate (3H-QNB) to identify muscarinic receptors and 125I-alpha-bungarotoxin (125I-BGT) to identify nicotinic receptors. Muscarinic cholinergic receptors were not found in the cornea. As a positive control, muscarinic cholinergic receptors were characterized in preparations of the iris-ciliary body. Specific binding of 3H-QNB to iris-ciliary body membrane preparations was saturable, with a Kd of 1.3 nM QNB. Specificity of the assay for muscarinic receptors was confirmed by the relative abilities of the following compounds to displace 3H-QNB: atropine greater than pilocarpine greater than hexamethonium. Nicotinic cholinergic receptors were not found in the cornea. As a positive control, nicotinic cholinergic receptors were characterized in preparations of the retina. Specific binding of 1252-BGT to retinal membrane preparations was saturable with both high and low affinity receptors (Kd values of 1.0 nM and 93 nM BGT, respectively). Specificity of the assay for nicotinic receptors was confirmed by the relative abilities of the following compounds to prevent 125I-BGT binding: curare greater than or equal to nicotine greater than hexamethonium greater than atropine. The lack of cholinergic receptors in the cornea, which has high levels of acetylcholine and related enzymes, suggests either an extraordinary use or a lack of function for acetylcholine in this tissue.


Photodynamically induced alteration of cornea endothelial cell function. Corneal endothelial cells were perfused in the specular microscope with varying concentrations of rose bengal. Corneas perfused with rose bengal in concentrations of 10(-6)M to 10(-5)M and exposed to light for periods of 0.5 to 5 min swelled at rates which were more rapid with both increasing concentration of rose bengal and increasing duration of light exposure. Corneas perfused with similar concentrations of rose bengal but not exposed to light did not swell. Combining rose bengal with 100 micrograms/ml superoxide dismutase did not reduce the corneal swelling following exposure to light, indicating that the photodynamically induced endothelial bengal perfusing solution eliminated corneal swelling following exposure of corneas to light. This indicates that the photodynamic effect of endothelium is secondary to cell functional alterations from the hydrogen peroxide produced during the dismutation reaction of superoxide free radical which is catalyzed by superoxide dismutase.


Photogrammetry of the optic disc in glaucoma and ocular hypertension with simultaneous stereo photography. Stereophotogrammetric evaluations of the optic cup were performed for normal, ocular hypertensive, and glaucomatous eyes. Average volume, area, and depth measurements were progressively larger from normal to ocular hypertensive to glaucomatous eyes, although the distributions of individual values exhibited considerable overlap among the three groups. Similar results were obtained for volume, area, and depth asymmetry between each pair of eyes. None of these measurements was able to distinguish accurately between normal and glaucomatous optic cups. However, normal eyes showed a high correlation (r = +0.85) between area and depth of the optic cup, whereas this area/depth relationship was reduced in ocular hypertensives (r = +0.63) and completely broke down for glaucomatous eyes (r = +0.04). Approximately 89% of the glaucomatous eyes and 47% of the ocular hypertensive eyes were beyond the range of normal area/depth correlation values. These findings represent an improvement over most previous attempts to quantitatively differentiate between normal and glaucomatous eyes on the basis of optic disc measurements alone, and support the hypothesis that optic disc damage usually precedes visual field loss in glaucoma. With further technical refinements such as computer image processing, stereophotogrammetry of the optic cup may become a valuable differential diagnostic technique for glaucoma.


Spectral sensitivity function measured by a rapid scan flicker photometric procedure. A rapid scan flicker photometric procedure is described whereby continuous spectral sensitivity functions are measured from unpracticed observers in 30 min. The 30 min includes instructions, practice, and data collection. Data are presented from four unpracticed observers age 12 to 42 years. Three practiced observers had their spectral sensitivities measured by both the conventional and rapid scan methods. The conventional method took 1.5 hr, measuring at 25 wavelengths and repeating each three times. The agreement between the rapid scan and conventional methods is satisfactory. Comparison with Judd's correction of CIEV (lambda) yields the same deviations as expected with conventional flicker photometry. The rapid scan procedure is shown to yield acceptably consistent data. The advantages of the rapid scan method for basic and applied vision research is discussed.


Assessment of the visual acuity of human color mechanisms with the visually evoked cortical potential. The amplitude of the human visually evoked cortical potential (VECP), which has been shown to vary as a function of the dimensions of checks in a checkerboard pattern, was used to objectively assess the visual acuity of the blue-sensitive compared with the red- and green-sensitive mechanisms in the eye. The results agree with psychophysical measures which have indicated poorer acuity of the blue system compared with the red and green systems.


Red fluorescence in older and brunescent human lenses. Brunescent lenses and normal human lenses more than 70 years old exhibit red fluorescence due to a fluorophor with emission maximum at 672 nm under excitation by the 647.1 nm line of krypton ion laser. The properties and mode of occurrence of this fluorophor suggest that its formation is highly pertinent to senile nuclear pathology.


Photically induced experimental exophthalmos: role of Harderian and pituitary glands. Exposure of adult male and female albino rats to high-intensity illumination for 17.5 hr results in a marked, transient exophthalmos, which persists for approximately 48 hr after the light exposure. Upon examination of the Harderian glands in these rats, a significant glandular weight increase was observed up to 2 days after light treatment. Analysis of individual glandular components showed that this weight increase was due to an increase in fluid content of the glands. The lipid and residue contents in the Harderian glands of exposed rats decreased significantly. When animals were hypophysectomized (HYPEX) prior to the short-term illumination period, there was no visible exophthalmos. However, when the Harderian glands were analyzed at necropsy, they had a similar relative increase in weight as compared to glands of intact rats, and this again was the result of increased fluid composition. The exophthalmos induced in intact animals resulting from an enlargement of the Harderian glands seemingly was due directly to a radiant energy-dependent mechanism and not to any pituitary hormone mediation. The edematous phenomenon was similar in Harderian glands of HYPEX rats, but visible exophthalmos was lacking, probably because of the atrophied condition of the glands in the absence of the pituitary.


Peripheral stimulation and human cyclofusional response. Cyclofusional responses consisting of both motor and nonmotor components were measured during stimulation in the peripheral visual field. A 5.75 degree torsional disparity presented in 10 degrees, 30 degrees, and 50 degrees diameter visual stimulus fields induced binocular, torsional eye movements averaging 2.8 degrees to 3.4 degrees. When torsional disparity was excluded from regions up to 30 degrees diameter in the center of the visual field, binocular torsional eye movements of 3.5 degrees to 4.4 degrees were observed. A presentation of simultaneous, conflicting torsional disparities in center and annular surround regions of the stimulus field also induced torsional eye movements which reduced the disparity in only one of the two regions while increasing it in the other. The directions of eye movement changed when the surround stimulus area was enlarged at the expense of the area of the conflicting central stimulus. Based on an objective method of monitoring eye position, the findings in this report suggest that peripheral stimulation exercises a strong influence on the cyclofusional motor response component and that under suitable conditions such stimulation may have a greater influence on the cyclofusional motor response than central stimulation.


A community health study in Jerusalem. Design and response. A longitudinal community health study was commenced in a neighborhood of western Jerusalem in 1969. Its main aims were the investigation of etiologic factors in selected common diseases and disabilities, the development and testing of epidemiologic tools for use in community diagnosis, the provision of a factual basis for decisions concerning community health care for the population studied, and the use of the findings in an evaluation of the effectiveness of community health care. In the first round, 90% of residents 25 or more years old were interviewed and 81% were examined. Among children under 15 years of age, the corresponding rates were 94 and 83%. Response was low among persons in the age range 15 to 24 years, especially males. People who were concerned about their health were readier to be examined. Response was not related to region of birth, education or other variables. The possible bias introduced by nonresponse appeared to be small except in the age group 15 to 24 years.


Prevalence of selected health characteristics of men. A community health survey in Jerusalem. The health status of males aged 15 or more years was studied as part of a community health survey in a neighborhood of western Jerusalem. Most subjects (75%) reported that they felt well; clinical appraisals revealed a need for treatment in 33%. Hypertension was found in 14% and coronary heart disease in 6%. Other common disorders included hemorrhoids (16%), varicose veins (11%), overweight (18%), hypercholesterolemia (13%), inguinal hernia (13%), symptoms of prostatic hypertrophy (10%) and diabetes (5%). The prevalence of specific symptoms of emotional ill health ranged from 6 to 23%. A quarter reported serious current problems; 10% were dissatisfied with their present life situation; and 10% had concentration camp experience. Half were current cigarette smokers. The prevalence of most disorders rose in successive age groups. Mean diastolic blood pressure, serum cholesterol, relative weight and the prevalence of cigarette smoking were lower in the oldest age groups. With some exceptions, the age trends were similar to those found in other populations.


Esophageal replacement in children: 10 years' experience. Esophageal replacement continues to be a challenging surgical problem. Currently advocated methods entail using reversed gastric tube or colon for the interposition. Between 1969 and 1978, 11 children underwent esophageal reconstruction. Their ages at operation ranged from 1 to 16 years. All the operations were performed in one stage. The right colon was used in seven children and reversed gastric tube in four. There were no postoperative deaths. Temporary salivary fistula and cervical anastomotic stricture were the most common operation-related complications. On the follow-up visit, at least six months after surgery, all the children were able to eat a normal diet. The use of reversed gastric tube avoids intestinal resection, preserves the ileocecal valve, shortens the operative period and preserves the possibility of an alternative procedure (colon interposition) if technical failure occurs. On the basis of our limited experience we advocate the use of reversed gastric tube for esophageal replacement.


Serum beta-glucuronidase activity during pregnancy in gestational diabetes. Serum beta-glucuronidase (S beta G) activity was investigated as an early indicator of diabetes in pregnant women. The enzyme activity was determined in the sera of three groups: nonpregnant women (18 to 40 years old) with and without glucose intolerance, pregnant women with and without glucose intolerance, and pregnant women with a family history of diabetes. The S beta G activity values (means +/- SD) in normal pregnant women were 603 +/- 223, 872 +/- 270 and 1,336 +/- 353 Fishman units during the three trimesters, respectively. A slight increase in S beta G activity was found in the sera of healthy pregnant women with a family history of diabetes during the first and second trimesters. High values of S beta G (2,765 +/- 392 units) were found in all stages of pregnancy in diabetic women. Thus, the determination of S beta G activity may be a valuable aid in the early detection of reduced glucose tolerance in pregnancy.


Development of a storable Leishmania tropica vaccine: field testing with frozen promastigotes. The development of a frozen vaccine against cutaneous leishmaniasis offers the possibility of controlling the quality, efficiency and sterility of the promastigotes used for inoculation. Thirty-nine soldiers in a settlement in a hyperendemic area were inoculated with a fresh isolate of Leishmania tropica that was stored at the temperature of liquid nitrogen. Thirty of the soldiers were injected by conventional syringe while the rest were inoculated by an intradermal jet injector. The infective material was transported either in ice or at liquid nitrogen temperature. All the subjects developed lesions at the site of inoculation, without unwarranted reactions. One month after inoculation 31 subjects were examined by a physician. All the reactions were positive--12 ulcers and 19 nodules. After four months, all 39 soldiers were examined: 25 (64%) had ulcers; eight (21%) had nodules; and six (15%) were without visible reaction. The different methods of transporting the vaccine, as well as the different responses of men and women, are discussed.


Autonomic nervous system disturbance in patients on chronic hemodialysis. To demonstrate autonomic nervous system (ANS) disturbances in patients on chronic intermittent hemodialysis, simple noninvasive tests were used. These included the Valsalva maneuver ratio, measurement of the changes in blood pressure and pulse rate following standing up from the supine position, the finger-immersion test and calculating the R-R interval ratio of the 30th to the 15th beat on the ECG following standing. It was found that in all the patients who were compared with normal volunteers, some ANS disturbances were present, as evidenced by at least three positive tests of the five described. The Valsalva maneuver ratio was positive in only 58% of the cases, possibly because it is a less sensitive test than the others.


Pituitary enlargement secondary to hypothyroidism associated with sublingual thyroid gland. Two patients with sublingual thyroid glands and hypothyroidism since childhood are described. Because of enlargement of the sella turcica both were erroneously diagnosed as having primary pituitary tumors resulting in secondary hypothyroidism. One of the patients was even treated with pituitary gland irradiation. Following substitution thyroid therapy, thyroid-stimulating hormone (TSH) levels promptly returned to normal. Ectopic thyroid glands, which are often incapable of adequate hormonogenesis, may cause secondary pituitary enlargement and lead to the suspicion of a pituitary adenoma. The correct diagnosis can easily be established by measuring serum TSH levels, which are elevated in the former condition.


[Pemphigus herpetiformis].

[Pemphigus herpetiformis]. Pemphigus herpetiformis is a separate form of pemphigus with its own features. Clinically it resembles dermatitis herpetiformis Duhring. Periodically there is an extraordinary violent itching. Histologically pemphigus herpetiformis shows an eosinophilic spongiosis. The important acantholysis can only be found by repeated biopsies. Because of the acantholysis and the intercellular autoantibodies, demonstrated by direct and indirect immunfluorescence, this dermatosis belongs to the group of pemphigus. The therapeutical response to 4,4'-diaminodimethyl-diphenylsulfone (DDS)--a similarity to dermatitis herpetiformis Duhring--is especially characteristic. Our own observation gives occasion to characterize this pemphigus variant, which is repeatedly described in the literature under different designations, as pemphigus herpetiformis.


[Human infestation by Sarcoptes scabiei var. bovis (cattle itch mite)]. Infestation by Sarcoptes scabiei var. bovis in a farmer is reported. He presented with an intensely itching eruption of erythematous papules on forearm, neck and abdomen. An environmental investigation yielded that four of the farmer's cows had mange. Sarcoptes scabiei var. bovis was isolated from skin-scrapings of the cows. Histology from a self-induced lesion revealed that Sarcoptes scabiei var. bovis penetrates the human skin, but does not--in contrast to var. hominis--form burrows. This finding corresponds with the clinical picture. The mite lies subcorneally, compressing the thinned epidermis. The surrounding corneal tissue shows a marked exsudative reaction. The various ways in which mites may infest the human skin are discussed.


[Parodontoplethysmography. A method of objective evaluation of the course of progressive scleroderma]. Parodontoplethysmography was repeatedly performed in seven patients with systemic sclerosis over a period of six years. The data obtained exactly correlated to improvement or deterioration in the patients' condition. Regular parodontoplethysmography is recommended in order to observe the course of the disease more objectively. Some of the examined patients roentgenographically showed a widening of the periodontal space, a typical feature of systemic sclerosis.


[Lichen purpuricus (lichen aureus)].

[Lichen purpuricus (lichen aureus)]. A 14-year old boy developed lesions, which clinically and histopathologically corresponded to the rare condition known under the term of lichen purpuricus seu aureus. The disease can be classified close to purpura pigmentosa progressiva.


[Dermatology in French Guiana].

[Dermatology in French Guiana]. In French Guayana, climatic and geographic conditions enhance development of numerous fungal, parasitic and microbial skin diseases. The most particular infectious diseases of this French department are lobomycosis, chromomycosis (Phialophora pedrosoi), creeping disease, cutaneous leishmaniasis, tungiasis, mycobacterial ulcus (Mycobacterium ulcerans) and papular dermatitis caused by nettling hairs of lepidoptera (Hylesia urticans). The occurence of these skin diseases is demonstrative of pathological ecology of the Amazonian country.


Planning, budgeting, and controlling--one look at the future: case-mix cost accounting. This paper outlines the system for cost accounting and managerial control which is an extension of the usually accepted departmental costing systems and takes as its units the 383 Diagnosis Related Groups (DRGs) considered to be the hospital's products. It is held that such an approach offers hospital managers a more powerful, analytic, budgeting, and cost-finding tool and offers the opportunity to involve the medical staff in the issues of how their practice patterns are affecting hospital costs.


Evaluation of emergency ambulance characteristics under several criteria. A methodology and analysis are presented for evaluating response time characteristics of emergency ambulance systems. The methodology is based on a Monte Carlo simulation technique and a heuristic optimal-seeking technique for locating emergency ambulances under several criteria based on response time distribution. Optimization criteria include minimum mean system response time, minimum system fractile response time and minimum level-loaded response time. The evaluation methodology is applied to the metropolitan area of Los Angeles County. Ambulance response characteristics and loads are discussed in detail. From these results alternative dispatch polices can be evaluated. Complementing the analysis is a presentation of a sensitivity analysis and an analysis of existing ambulance sites. Unique to the methodology is the adaption of the heuristic optimal-seeking technique to include any of the three criteria and the effectiveness of the methodology for analyzing small or large ambulance systems.


Measuring hospital medical staff organizational structure. Based on organization theory and the work of Roemer and Friedman, seven dimensions of hospital medical staff organization structure are proposed and examined. The data are based on a 1973 nationwide survey of hospital medical staffs conducted by the American Hospital Association. Factor analysis yielded six relatively independent dimensions supporting a multidimensional view of medical staff organization structure. The six dimensions include 1) Resource Capability, 2) Generalist Physician Contractual Orientation, 3) Communication/Control, 4) Local Staff Orientation, 5) Participation in Decision Making, and 6) Hospital-Based Physician Contractual Orientation. It is suggested that these dimensions can be used to develop an empirical typology of hospital medical staff organization structure and to investigate the relationship between medical staff organization and public policy issues related to cost containment and quality assurance.


Complete sequence of the gamma chain from the fetal hemoglobin of the baboon, Papio cynocephalus. The amino acid sequence of the hemoglobin gamma chain from a baboon, Papio cynocephalus, was determined by automated sequencing of the intact chain and six fragments generated by specific clevage reactions. The existence of structural heterogeneity at position 75, where both valyl and isoleucyl residues were found, is suggestive of the presence of nonallelic V gamma- and I gamma-chain genes in this species, and further emphasizes the extent to which the genetic basis of hemoglobin production among many higher primates is similar. Comparison of the sequences of those gamma chains from Homo sapiens, Pan troglodytes, Macaca nemestrina and P. cynocephalus that have been well characterized attests to the conservative nature of gamma-chain evolution among the Anthropoidea, the differences in sequence between any two of these chains ranging from none (between the A gamma and G gamma chains of P. troglodytes and H. sapiens) to no more than five (between the V gamma chains of P. cynocephalus and the A gamma chains of H. sapiens).


A simple microchromatographic column for determination of hemoglobins A1a + b and A1c. A simple microchromatographic homemade column was devised for the measurement of glycosylated minor hemoglobin fractions. The mean and one standard deviation of hemoglobins A1a + b, A1c and A1a + b + c determined by the homemade column in 150 nondiabetic controls and 56 juvenile onset insulin-dependent diabetics were 2.6 +/- 0.5%, 6.0 +/- 1.0%, 8.6 +/- 1.1%, 3.3 +/- 0.9%, 13.7 +/- 2.2% and 16.9 +/- 2.8% respectively. A twofold increase in hemoglobins A1c and A1a + b + c levels was observed in the diabetics as compared to the non-diabetic controls suggesting that the homemade column is valid for the measurement of all three glycosylated hemoglobin fractions and assessment of blood glucose control in diabetic patients. The homemade column procedure yields accurate and reproducible results, is simple to perform, inexpensive, relatively rapid and may be used in the routine clinical laboratory. Hemoglobin A1a + b + c levels measured by a commercial column in 35 non-diabetic controls and in 56 diabetics showed good correlation (R = 0.91) with hemoglobin A1a + b + c levels determined by the homemade column. The commercial column is valid for the measurement of the combined glycosylated hemoglobin A1a + b + c fraction and may be used in the routine clinical laboratory to assess diabetic control.


Application of an automatic oxygenation technique to analysis of oxygen equilibrium curves for hemoglobinopathic red cells and functional screening of clinically important hemoglobinopathies. The automatic oxygenation technique of Imai et al (Biochimica Biophysica Acta, 200:189--196, 1970) was slightly modified and applied to the study of oxygen equilibrium curves of dilute, red-cell suspensions from normal subjects and individuals with hemoglobinopathies, enzymopathies, and other hematologic disorders. The p50 values of non-smoking, normal adults were 25.9 +/- 0.6 mm Hg at pH 7.4 and 37 degrees C, and corresponded to the values for whole blood reported in the literature. The oxygen equilibrium curves of suspensions from subjects with enzymopathies revealed shifts in position which are thought to be due to alterations in the concentration of 2,3-DPG of the red cells. Abnormalities in shape of the equilibrium curves were observed only for the hemoglobinopathic red cells, and could best be illustrated by the abnormally low Hill's exponent (n*). Analyses of the n* values of 34 patients with various red-cell disorders of unknown causes led to the identification of ten cases showing low values. In five of the ten patients, the presence of an abnormal hemoglobin was confirmed using column chromatography on Amberlite CG--50. These results point to the usefulness of the Hill Plot analysis of red-cell oxygen dissociation curves in functional screening for clinically important hemoglobinopathies.


Hemoglobin Riyadh-beta 0-thalassemia in an Indian family. An Indian (Asian) patient with compound heterozygosity for Hb Riyadh and beta 0-thalassemia is described. Hb Riyadh forms about 95% of the hemoglobin present. The clinico-pathological picture is identical to that of simple beta-thalassemia trait confirming the harmless nature of the substitution beta 120(GH3) Lys leads to Asn.


Development of the squamosomandibular articulation in the Mongolian gerbil (Meriones unguiculatus). II. Succinate dehydrogenase activity. Succinate dehydrogenase activity has been studied, according to the method of Nachlas et al. (1957), in the developing tissues forming the squamosomandibular articulation in the Mongolian gerbil from its inception through the sixty postnatal day. Increased activity was observed in the chondroblasts, osteoblasts and mesenchymal tissues of the developing articulation. The chondroclasts of the developing mandibular condyle displayed intense reaction as did the osteoclasts of the developing bony articulation. Succinate dehydrogenase activity appeared to be related to the functional maturity of the cellular elements of the developing joint.


Cytochemical localization of catalase and several hydrogen peroxide-producing oxidases in the nucleoids and matrix of rat liver peroxisomes. The distribution of catalase, amino acid oxidase, alpha-hydroxy acid oxidase, urate oxidase and alcohol oxidase was studied cytochemically in rat hepatocytes. The presence of catalase was demonstrated with the conventional diaminobenzidine technique. Oxidase activities were visualized with methods based on the enzymatic or chemical trapping of the hydrogen peroxide produced by these enzymes during aerobic incubations. All enzymes investigated were found to be present in peroxisomes. Catalase activity was found in the peroxisomal matrix, but also associated with the nucleoid. After staining for oxidase activities the stain deposits occurred invariably in the peroxisomal matrix as well as in the nucleoids. In all experiments the activity of both catalase and the oxidases was confined to the peroxisomes. The presence of a hydrogen peroxide-producing alcohol oxidase was demonstrated for the first time in peroxisomes in liver cells. The results imply that the enzyme activity of the nucleoids of rat liver peroxisomes is not exclusively due to urate oxidase. The nucleoids obviously contain a variety of other enzymes that may be more or less loosely associated with the insoluble components of these structures.


Quantitative measurement of glucose-6-phosphate dehydrogenase in cortical fractions of the rabbit nephron. A quantitative fluorimetric method is described for estimating the activity of glucose-6-phosphate dehydrogenase in isolated fractions of rabbit nephron from the superficial part of the renal cortex: macula densa, proximal convoluted tubule, distal convoluted tubule and glomerulus. The mean activity in the macula densa region was 2.5 X 10(-18) mol/micrometers 3/min, which was about twice the mean activity of the proximal and distal tubular cells and four times that of the glomeruli. As glucose-6-phosphate dehydrogenase is located in the cytoplasm, the average cytoplasmic enzyme activity of the different tubular cells was calculated: macula densa activity was 4.0 X 10(-18) mol/micrometers 3/min whilst proximal tubular cells showed about a third, and distal tubular cells about a quarter of this activity.


The multiple forms of brain acetycholinesterase. III. Implications for the histochemical demonstration of acetylcholinesterase. The multiple forms of acetylcholinesterase (AChE, E.C. 3.1.1.7) have been investigated with regard to their histochemical demonstrability. Their pattern is influenced by buffer treatment, fixation, and by incubation conditions causing aggregation and disaggregation as well as loss or inactivation of individual forms. The standard histochemical method for AChE preferentially demonstrates the high molecular forms. Most of the oligomer forms are washed out or inactivated. A selective demonstration of the highly aggregated forms is possible either by inhibition of the oligomers with diisopropylfluoridate (DFP) or by specifically dissolving them out. No reason could be found for the selective demonstration of the low molecular weight forms.


Acid phosphatase in the guinea-pig oocytes. In guinea-pig oocytes, at every developmental stage, acid phosphatase is found histochemically in cytoplasmic granules. Ultracytochemically the reaction product is located in lysosomes and is some cisternae of the rough endoplasmic reticulum, but not in cortical granules or in vesicles with a rough endoplasmic reticulum membrane which are filled with a moderately dense homogeneous substance. It is discussed whether the acid phosphatase transforms reserve material into a storable form as has been proposed for the deposition of vitellogenin in the oocytes of lower vertebrates.


Tissue-specific changes in nuclear RNA content during early development of Triturus vulgaris. During early development of Triturus vulgaris, as a measure for nuclear activity in neuroectoderm, mesoderm and endoderm, nuclear RNA content was determined by cytochemical methods. In the first stages of gastrulation, that is to say during the early phase of neural induction, the RNA content of the inducing system is considerably higher than in the reacting system. Then, with a phase-shift of about 10 h, the RNA content of the neuroectoderm increases quickly also. In the following stages the nuclear RNA content of both regions is reduced. A second continuous increase in the RNA amount coincides with the formation of the neural tube. In the mesoderm, enhancement of RNA content correlates with cytodifferentiation of the chorda. In all stages the RNA content of the endoderm is higher than in the other tissues and it becomes successively diminished from the early gastrula to the tailbud stage.


Effect of clofibrate on the small intestine of fetal mice. Pregnant Swiss ICR mice were injected with clofibrate at different dosages and time intervals, and embryos were removed either at 17 or 18 days of gestation. In embryos sacrificed at 17 days the level of intestinal catalase activity of the proximal and distal halves in the treated groups is identical in any case to that of the controls. In embryos sacrificed at 18 days, the rise in the level of catalase activity in the proximal half of the small intestine in treated groups is dose dependent up to a certain limit: with repeated injections the increase reaches a plateau. The distal halves of treated groups are much less responsive and an increase in catalase activity was noted only with repeated injections. In untreated embryos circular DAB-positive microperoxisomes (200 nm in diameter) and tubular structures (100 nm in thickness) are seen in the duodenum at 18 days of gestation. At the same stage, only circular microperoxisomes are identified in the ileum. After clofibrate treatment circular and tubular microperoxisomes are observed in the ileum also. It is concluded that clofibrate induces a rise in catalase activity in the embryo, only after 17 days of gestation. These observations are discussed in relation to the biogenesis of microperoxisome.


Sodium and calcium localization in cells and tissues by precipitation with antimonate: a quantitative study. Komnick's antimonate technique, which was devised to localize Na+ in cells and tissues, was studied quantitatively. Some modifications, as well as its application to Ca2+ localization, were also investigated. We combined measurements of Na+ and Ca2+ retention in plant roots during the various procedures, electron microscopy, autoradiography, and semiquantitative X-ray microanalysis. We were able to show that (at least in barley roots) antimonate does not precipitate at all with Na+, irrespective of the Na+ content of the tissue or the method of antimonate application. (Even during precipitative freeze dissolution or after freeze drying, no Na+ is precipitated.) By means of Komnick's antimonate technique Ca2+ is trapped within the tissue, but only after serious dislocation. Perspectives for reliable localization of diffusible ions in cells and tissues, by precipitation simultaneously with conventional fixations, are bad.


Cholinesterases and choline acetyltransferase in the longitudinal muscle of the guinea pig ileum. In order to gain insight into the possible role of the ACh-system in the smooth muscle cell, the presence of choline acetyltransferase, acetylcholinesterase and butyrylcholinesterase was studied in the longitudinal muscle of the guinea-pig ileum after the mechanical removal of Auerbach's plexus. Such treatment completely removes all nerve elements as confirmed by histochemistry and electron-microscopic examination. It was found that in the longitudinal muscle devoid of all nervous elements a substantial percentage of the activity of all three enzymes still remained. Ultrastructural localization of acetylcholinesterase and butyrylcholinesterase was observed on the sarcolemma, sarcoplastic reticulum, nuclear membrane and invaginations of the sarcolemma. The localization of cholinesterases coincides with sites which are presumably involved in calcium movements during contraction and relaxation. It is well known that the depolarized smooth muscle responds to exogenous ACh with a reversible, calcium dependent contraction and it was suggested that ACh may act by increasing the influx of calcium through the cell membrane or by liberating calcium from its bound form. The presence of choline acetyltransferase and cholinesterase activities in the muscle cell proper, as well as the localization of cholinesterases on structures connected with calcium movements, support the coexistence of an intrinsic cholinergic mechanism in the smooth muscle.


Immunocytochemical demonstration of the neurosecretory X-organ complex in the eyestalk of the crab Carcinus maenas. An antiserum was obtained by immunizing rabbits with sinus gland extracts from Carcinus maenas. The antiserum is almost exclusively directed against neurosecretory material in the medulla terminalis X-organ (MTGXO), as demonstrated by the peroxidase--antiperoxidase (PAP) staining method in light and electron microscopic studies. Radioimmunological binding studies indicate the presence of antibodies against the crustacean hyperglycemic hormone (CHH) or the black pigment dispersing hormone (BPDH) in the antiserum. The results suggest that the neurosecretory perikarya of the MTGXO are the sites of production of CHH and/or BPDH.


Staining and relative determination of elemental contents by the laser microprobe. An improved laser microprobe procedure is developed and applied to the measurement of calcium content in microareas of right and left subepicardial muscles. The staining of canine cardiac muscles by Methylene Blue solution (1% w/v) was found to improve sampling efficiency. Elemental content is proportional to T-1/gamma, where T is the transmittance of the characteristic emission line of the element of the photographic plate and gamma is its contrast. In the present system, the calcium content is analyzed using T-3.2. We find that the staining of samples and the determination of T-1/gamma are useful procedures in the application of laser microprobe to the study of elemental content in biologic microareas.


Nucleoside excretion in breast cancer: comparison with other biochemical tumour-index-substances. [We have measured four urinary nucleosides (dimethylguanosine, 1-methylinosine, pseudouridine and beta-aminoisobutyric acid)in patients with benign breast disease and patients with early and advanced breast cancer in order to assess their value as tumour-index-substances. We compared the results with other biochemical indices of breast cancer and sought and correlations between these indices.  The results indicate that few abnormalities occurred in patients without overt metastases and these did not predict early relapse. In those with metastatic disease, dimethylguanosine excretion was most frequently elevated.   Correlations were observed between some of the nucleosides and lysozyme and alpha1-antirypsin.


Substance P-like immunoreactive nerves in mammalian lung. Substance P-like immunoreactivity was located in nerves in the lungs of guinea pig, rat, mouse and neonatal pigs. These nerves were regularly observed in association with both airways and blood vessels in all region of the lung. They appeared to be more numerous in the guinea pig than in the other mammals studied and differences in distribution were observed. The finding of substance P-like immunoreactive nerves in the lung suggests the presence of another regulatory system within the mammalian lung.


Cytochemical characterization of cultured adult, guinea pig glomerular cells. Methods are described for culture of intact or trypsin-digested adult guinea pig glomeruli. Cell types grown from intact glomeruli were distinctly different from those which dominated cultures of trypsin dissociated glomerular cells as determined by transmission and scanning electron microscopy as well as by fluorescence or enzyme cytochemical reaction with lectins and immunofluorescence cytochemical staining for actin or fibronectin. Cells with long cytoplasmic extensions (glomerular epithelial cells), cultured from intact glomeruli, have strong affinity for concanavalin-A and soybean agglutinin which react with glucose and galactose residues respectively. Rectangular cells (glomerular mesangial cells), cultured as the predominant cell from trypsinized glomeruli, have strong affinity for wheat germ agglutinin which reacts with N-acetyl glucosamine. Both of these cell types stained immunocytochemically for fibronectin and actin although the intracellular patterns were somewhat different. These two types of cells are able to secrete extracellular basement membrane material.


Tissue culture of normal rat glomeruli. Isolation and morphological characterization of two homogeneous cell lines. Glomeruli were isolated from rat kidneys using enzymatic digestion, sieving and differential centrifugation. They were cultured in RPMI medium containing 15 per cent decomplemented fetal bovine serum. Using 3H-thymidine, two peaks of cell division occurred: the first was observed after 2 days in culture and reached its maximum on day 6; the second peak, starting on day 12, reached its maximum on day 22. Two cell types were identified by phase contrast, immunofluorescent and transmission electron microscopy. The first peak contained epithelial cells until day 6, while the second contained smooth muscle-like (mesangial) cells on day 30. The difference in the growth capacity of epithelial and smooth muscle-like cells allows their separate isolation by performing subcultures on day 6 for the former cells and on day 30 for the latter.


A new experimental model of human cachexia. A hypernephroma removed from a male patient who had lost 30 kg in weight in the two months preceding surgery was grown as a non-metastasizing transplantable xenograft in immune-suppressed mice. The tumour produced a considerable weight loss (greater than 25 per cent) in the mice at a stage when it comprised less than 5 per cent of the total body weight. A slight fall in food intake of the tumour-bearing mice was noted, but animals bearing other non-cachectic mouse and human tumours had much lower food intakes without accompanying weight loss. No obvious defects in gastrointestinal absorption were detected nor was any gross increase in basal metabolic rate observed. The precise mechanism producing the severe cachexia remains to be established, but elaboration of humoral factors by the tumour seems probable. This model of cachexia bears a closer relation to the clinical situation than do other experimental animal tumour models currently available.


The sites of origin of gastric cancers and ulcers in relation to mucosal junctions and the lesser curvature. A histological mapping procedure was used to study 32 stomachs bearing small cancers and 23 stomachs bearing ulcers. Over 80 per cent of gastric cancers and peptic ulcers occurred within 2 cm of both a mucosal junction and the lesser curvature. They showed slight differences in their longitudinal relationship to the pyloric junction. There were differential characteristics between the groups of cancers arising at each of the three mucosal junctions. Cancers at the pylorus and cardia were more common in males (M:F--2.6:1) and were predominantly well differentiated, whereas those from the intermediate zone were more common in females (M:F--1:1.8) with a relatively higher proportion of undifferentiated cancers. These and other features suggest that gastric cancers should be subdivided according to the junction of origin.


Psychodynamics and treatment of sexual assualt victims. This paper discusses (1) how my own interest in the treatment of sexual assualt victims developed and how I view the scope of this problem; (2) myths and facts about sexual assault; (3) common reactions of those who work with rape victims; (4) the rape trauma syndrome; (5) an approach to immediate and short-term treatment; and (6) the long-term effects of sexual assault and related treatment issues.


The use of detachment in narcissistic and borderline conditions. In summary, looking at some of the ways in which detachment issues are organized and expressed in the psychoanalytic treatment of differing character structures, makes the need for a finely tuned interpersonal environment in analysis particularly compelling. Finding the appropriate spot to occupy in the dimension of distance and closeness with a detached patient depends heavily on the ability to maintain an empathic "feel" for the conflict that is closest to the surface of the detachment, and cannot easily be dealt with by broad rules of thumb or diagnostic conceptualizations of detachment as simply a global entity.


Audiometric results following endolymphatic sac surgery. Decompression and drainage of the endolymphatic sac is a surgical procedure which was developed to relieve vertigo and hopefully to maintain or improve hearing in patients with Meniere's disease. In this study, 16 medically diagnosed Meniere's disease patients who underwent endolymphatic sac surgery were followed audiometrically for a period of up to three years. Pre- and postoperative audiometric and other symptomatic findings were reported. Results indicated that in the greatest majority of cases hearing remained essentially unchanged or was improved. Poorer hearing was found in 26.3% of the cases for pure tones and in 15.8% of the cases for speech reception thresholds and speech discrimination scores. Due to the fluctuating nature of auditory thresholds in Meniere's disease, it was found to be essential that patients be followed postoperatively for a period of at least three years.


Auditory brainstem volume-conducted responses: origins in the laboratory mouse. Volume-conducted, short-latency auditory-evoked potentials were examined in the laboratory mouse with lesions and local recording used to localize their sources. PI corresponds in time with N1 recorded from the round window, while isolation of the eighth cranial nerve from the brainstem results in the loss of all post-PI components. PII latency agrees with that of evoked potentials recorded from the cochlear nucleus. PIII latency corresponds with that of evoked potentials from the vicinity of the contralateral superior olivary nucleus, and lesions of this and closely related contralateral structures abolish PIII from the vertex recordings. PIV is reduced in amplitude by unilateral brainstem lesions between the superior olive and the inferior colliculus. Evoked potentials and lesions localized PV to the vicinity of the lateral regions of the contralateral inferior colliculus. PVI disappeared when areas anterior to the inferior colliculi were lesioned. Although minor species differences may exist, it was concluded that the sources for PI to V in the mouse closely resemble those in the cat, and they agree well with the limited data from the human. This technique may now be applied to studies of the numerous auditory mutants of the laboratory mouse.


Attention and respiration audiometry.

Attention and respiration audiometry. The effect of attention on auditory responses obtained with respiration audiometry was examined on twenty normal-hearing adults. Ten subjects were instructed to listen carefully for the auditory stimuli during testing, while the other ten were not instructed. The results revealed that the change in respiration resulting from sound stimuli for the instructed subjects was three times greater than for the uninstructed group during the first 11-tonal sequence. However, during the third sequence, more responses were obtained from the uninstructed subjects. There was little evidence to suggest that the respiratory changes to sound were greater in magnitude or in number as the intensity of the sound approached behavioral threshold. The results suggest that the level of attention affects the number and pattern of respiratory responses to sound.


Recovery characteristics of the acoustic reflex. Acoustic-reflex recovery time was measured as a function of activator intensity level and duration for broad-band noise and a 500-Hz tone in 10 normal-hearing subjects. The activating signals were presented at 5 and 10 dB above individual acoustic reflex thresholds for durations ranging from 0.25 to 100 sec. Reflex-recovery times were similar across both activators and across activator intensity levels. Recovery time was relatively constant for activators of 2 sec or less and increased for longer activator durations. Portions of the results from temporary threshold shift experiments are explained on the basis of acoustic reflex recovery characteristics.


Dynamic tympanometry.

Dynamic tympanometry. Tympanometry was performed under the contraction of the middle ear muscles (dynamic tympanometry). A tympanogram of lesser compliance was observed under a stapedius reflex which was produced by contralateral acoustic stimulation. In patients with reversed (downward) stapedius reflex, the dynamic tympanogram showed either a higher peak amplitude or a shift of conventional tympanogram to the negative pressure side. Voluntary contraction of the tensor tympani produced a lesser compliance with positive pressure, whereas there was an apparent increase of compliance with negative pressure in the external auditory meatus. A shift of the dynamic tympanogram to the negative pressure side was interpreted as being due to contraction of the tensor tympani muscle. Dynamic tympanometry may also be utilized as a recording of reflex decay.


Presbycusis: the aging ear. Part I.

Presbycusis: the aging ear. Part I. The aging ear is a particularly vexing problem. This review of the literature covers much of the pertinent information and leads to some suggested research which we hope to pursue. It seems to us that research directed toward increased knowledge of the auditory blood supply and a better understanding of the function of the stria vascularis will add much to our understanding of the aging ear.


Changes in number and type of errors on repetition of acoustically distorted sentences as a function of age in normal children. The intelligibility of recorded sentences, distorted by binaural switching, interruption, and low-pass filtering, was investigated in 53 children ranging in age from five to eleven and in adults. All had normal hearing. The sentence vocabulary was pretested for comprehension, articulation errors were evaluated in a way so as not to influence test results, and length and structure of the sentences were controlled. The results indicated that although the performance of children increased with age, the 11-year-old group had not attained adult performance. Error analyses showed that most errors for all age groups were acoustically unrelated to the distorted message, although adults made more acoustically related errors than did children. When children made errors in sentences, other errors (e.g., substitutions) were made to preserve the syntax or semantic integrity of the message.


A comparison of procedures and materials for speech reception thresholds. Ascending and descending procedures were used to obtain speech reception thresholds from 32 normal-hearing subjects whereas digits and spondee words were used as test materials. Comparisons of thresholds were made for the two procedures and materials. Results indicated that slightly lower (less SPL) speech thresholds resulted from the use of a descending procedure with both types of material. In addition, digit material was found to yield generally lower threshold values than spondees. Advantages to the use of the two procedures and materials are discussed.


Surgical treatment of long-term sensorineural hearing loss due to labyrinthine fistula. Perilymphatic fistula, usually in the round or oval window, causes a variety of symptoms, including sensorineural hearing loss. Surgical repair of these fistulas has resulted in restoration of hearing in some cases. It has been suggested that surgery must be performed within 2 months of the trauma if improvement in hearing is to occur. This paper presents the case of a patient whose fistula and resulting hearing loss had persisted ten years before surgical repair. Restoration of normal hearing and discrimination of speech occurred in the ear which had previously presented a severe sensorineural hearing loss with no useful discrimination for speech. The authors usge audiologists and otolaryngologists to consider the possibility of fistula in cases of sudden hearing loss, even when years have elapsed since the trauma. Their experience suggests that surgery may be successful in restoring hearing after many years.


The effect of ear protectors on word discrimination in subject with normal hearing and subjects with noise-induced hearing loss. Two groups of subjects with normal hearing and three groups of subjects with noise-induced hearing loss were studied for the effect of ear protectors on word discrimination in two different speech-to-noise ratios. Various interactions in the analyses of variance were shown to be significant. The important demonstration in this study is that at high speech intensity, subjects with normal hearing should obtain higher word discrimination score with ear protectors than without if the signal-to-noise ratio is high. Albeit, the same is not true for a low signal-to-noise ratio, for a low speech intensity, or when subjects have hearing losses; the improvements in these conditions are not high enough to warrant the disuse of ear protectors. Results are discussed and compared with other studies.


Test-retest variability in testing hearing of speech. The repeatability of W-22 PB tests at levels of speech reception threshold (SRT) plus 5 to 30 dB in quiet and in white noise at S/N = 0 and 7 dB at a level of SRT plus 20 dB for 28 subjects with sensorineural hypoacusis. Standard deviations at various levels were from 9 to 13% compared to a standard deviation of less than 8% at SRT plus 40 dB. The lower variability at SRT plus 40 dB permits satisfactory confidence in the average of two measurements. However, it was found that more tests are required for the same confidence at the lower sensation levels. A protocol is suggested for carrying out this requirement.


Influence of ear canal air pressure on acoustic reflex threshold. This study was undertaken to investigate the effects of ear canal air pressure variation on the threshold of acoustic reflex. The acoustic reflex threshold was obtained to 500 and 1000 Hz activating signals as pressure was varied between +/- 200 mm H2O. The results demonstrated a reduction in sensitivity of the acoustic reflex with variations in positive or negative air pressure. Observation of the conductance component of admittance consistently required higher intensity levels to elicit the acoustic reflex. Clinical implications are that external air pressure can vary within a range of +/- 80 mm H2O and continue to maintain the acoustic reflex threshold close to its value obtained at maximum compliance.


Audiological manifestations in "split brain" patients. Traditional peripheral hearing tests (pure-tone thresholds, speech reception thresholds, and speech discrimination) and selected "central" hearing tests were administered to three commissurotomized patients. One patient was tested both pre-and postoperatively, whereas the remaining two were tested only postsurgery. Results indicated that commissurotomy had no apparent effects on performance on the peripheral tests. However, various tests in the central battery showed definite abnormal results. Most significant were the results from dichotically presented speech stimuli which repeatedly showed total absence of responses for stimuli presented to the left ear. Additional experimentation indicated this monaural deficit could be overcome by reducing the intensity level of right ear stimuli. Results for low-redundancy, monotically presented speech stimuli also indicated a left ear deficit; however, these results were not as consistent as the dichotic data.


The effects of various front-to-back ratios on the performance of directional microphone hearing aids. Twenty-four sensorineural hearing-impaired adults were evaluated using four directional microphone hearing aids differing only in front-to-back ratios. The speech material utilized was the Synthetic Sentence Identification Message Competition Ratios of 0, -10, and -20 dB. The primary signal was presented from a 0 degree azimuth with the competing message was presented from a direct overhead location. The results revealed a systematic improvement in speech understanding as the size of the front-to-back ratio increased. This relationship was not significantly affected by the difficulty of the listening situation.


Prediction of hearing aid users' satisfaction. This study raised the question of whether certain methods of hearing aid evaluation could predict subjects' satisfaction and willingness to use their aids. For this purpose, we compared two hearing aid evaluation methods on 30 subjects between the ages of 55 and 65 years, all of whom were hearing aid users for some months. Five signal-to-noise ratios were used. The results of this experiment indicated a significant and positive correlation between subject satisfaction and subject willingness to use the hearing aid. Results of multiple regression analyses indicated that both evaluation methods were better predictors of usage than of satisfaction.


Newborn high-risk hearing screening by maternal questionnaire. State-wide, high-risk hearing screening is made possible in Utah through the use of a questionnaire designed for maternal response during hospitalization. The mothers of those determined high risk are sent a follow-up questionnaire when the infant is 6 to 8 months of age, and a determination is made for audiological testing on the basis of her response. Questionnaires (26352) were received on 50,700 live births, of which 4,591 (17.4%) were categorized high risk. Of the high-risk infants, 181 (3.9%) were determined at risk after follow-up, and 54 (20.8%) of these were found hearing impaired. Questionnaire item analysis is presented. Concerns regarding response validity and low return rate are discussed as is the pilot use of the birth certificate as the initial screening device.


Response behavior around auditory threshold. Normal adults, hearing-impaired preschool children, and normal-hearing mentally retarded children were assessed across repeated measures for auditory thresholds at 250 and 1000 Hz. Each subject's total performance across repeated measures was plotted by group by frequency relative to the last point of 100% correct response and interpolated thresholds. The results indicate that the steepness of the percentage of correct response performance curves and the variability of response performance above and below interpolated threshold were related to differences between the adult and child groups (mental age) and not between types of hearing populations (hearing sensitivity). The relationship between these results and experience with the signal is speculated.


Auditory-visual interaction in a dichotic listening task. Eleven normal adults identified consonant-vowel syllables (CV's) under three conditions after extensive training in the tasks. The auditory condition consisted of the simultaneous presentation of dichotic CV's. The Auditory-Visual I condition was the presentation of dichotic CV's with the simultaneous presentation of a visual CV to both eyes. The visual CV was always the same as one of the two auditory CV's. In the Auditory-Visual II condition, the auditory dichotic and visual CV's were again presented, but the visual CV was radomly varied so that it might or might not be identical to one of the auditory CV's. No significant difference between the right and left ears were found; however, there was a slight numerical superiority, especially in the auditory condition, in favor of the right ear. The presence of a visual stimulus tended to reduce the numerical superiority so that both ears performed more nearly the same. No significant differences were found in the performance of the right ear under the 3 test conditions. The left ear performance, however, tended toward enhancement with the presentation of a noncompeting visual stimulus but was significantly reduced when the visual stimulus competed with the auditory stimulus. A similar pattern was found under a double correct data analysis. Overall auditory performance was significantly poorer than was visual performance regardless of ear or test condition. Finally, error responses were more likely to be placed of articulation errors than voicing errors.


Power spectral analysis of auditory evoked response. Five normal hearing adults were examined for power spectral analysis of AER to 1000-Hz pure tone. Major frequency components of responses to stimuli at 50 dB hearing level exist at 1 to 14 c/s. The power spectra of responses to stimuli at 10 dB hearing level are greater than those of the SBA in the frequency components between 3 and 9 c/s; furthermore, the total power of 3 to 9 c/s indicates a clear difference between the 2. Incidentally, at 512-msec analysis time, the total power of 3 to 9 c/s of the AER are significantly greater than that at 1024-msec analysis time, whereas those of the SBA show little discrepancy at the 2; thus at 512-msec analysis time, the total power of 4 to 9 c/s yields a clear difference between the AER and the SBA responses averaged over 50 stimuli even at 10 dB hearing level.


Tympanometry:between ear symmetry and normative values. Marked asymmetry of auditory function between left and right ears would normally be indicative of some abnormality. This study was designed to investigate the limits of tympanometric symmetry in normal individuals. A limiting ratio of 4/3 between left and right ear compliances is suggested. Applying this criterion and strict criteria for normality of middle ear pressure and reflex thresholds, a value for middle ear compliance was obtained with a considerably smaller range for "normality" than from previous studies. A marked difference between middle ear compliances of male and female subjects was observed, and evidence was adduced to suggest that this was due to differences in size of the ear canal and tympanic membrane.


The stability of and the relation between the acoustic reflex and uncomfortable loudness levels. Acoustic reflexes and uncomfortable loudness levels were recorded for eight normal-hearing listeners on eight separate occasions and eight listeners with sensorineural hearing impairments on three to four occasions. Frequencies tested were 500, 1000, 2000, and 4000 Hz for both measures. Neither acoustic reflexes nor uncomfortable loudness levels was found to vary significantly across sessions for either the normal or hearing impaired listeners. However, significant intensity differences were noted between acoustic reflexes and uncomfortable loudness levels, for both subject groups, and these differences were dependent upon subject and frequency.


Effect of parenchyma and length changes on vessel pressure-diameter behavior in pig lungs. At several transpulmonary pressures (Ptp), the pressure-diameter (PD) behavior of the largest intraparenchymal arterial segment in the isolated pig lung was compared with the behavior of the segment after its excision from the parenchyma and its extension to lengths equivalent to those in the intact state. For physiological changes in length, as may occur with lung inflation during Ptp changes from 4 to 25 cmH2O, excised-vessel diameters did not change significantly at a constant transmural pressure. The excised-vessel PD behavior was not significantly different from the intact-vessel PD behavior at a Ptp of 4 cmH2O. At any constant arterial pressure, intact-vessel diameters became larger as Ptp increased. Estimates of the perivascular pressure (Px) obtained by directly comparing intact-vessel and excised-vessel PD curves were as follows: 1) Px was equal to pleural pressure at a Ptp approximating the functional residual capacity; 2) Px decreased almost linearly as Ptp increased; and 3) Px decreased with a fall in arterial pressure. These results are consistent with direct measurements of the perivascular interstitial fluid pressure.


Tutorial paper:principles and characteristics of automatic gain control hearing aids. Among the available auditory rehabilitative resources, automatic gain control (AGC) hearing aids comprise a unique class of personal amplifying systems. They are unique because of their capability of achieving some degree of self-regulation. However, partly due to the standard methods of portraying and describing electroacoustic data for conventional (non-AGC) aids, certain characteristics of AGC aids, such as are related to signal and noise relations over time, seem to be commonly unappreciated by the typical clinician. This paper discusses some principles of amplifying behavior that are common to all AGC hearing aid systems, as well as various design modifications. The ramifications of these properties are pointed out with a view towards greater clinical implementation of the available technology.


Recovery from maximal effort exercise: lactate disappearance and subsequent performance. The effects of differing recovery patterns following maximal exercise on blood lactate disappearance and subsequent performance were examined. Nine subjects completed four randomly assigned experimental sessions. Each session consisted of a 5-min maximal effort performance test conducted on a Monark bicycle ergometer (T1) followed by 20 min of recovery and a second 5-min maximal effort performance test (T2). Blood lactate levels were measured during min 5, 10, 15, and 20 of recovery. Recovery patterns consisted of passive recovery (PR), active recovery below anaerobic threshold (AR less than AT), active recovery above anaerobic threshold (AR greater than AT), and active recovery above anaerobic threshold while breathing 100% oxygen (AR greater than AT + O2). Blood lactate levels prior to T2 were significantly different across treatments (P less than 0.05). Comparison among treatments and between T1 and T2 revealed no significant differences in work output. It was concluded that while lactate disappearance following severe exercise can be affected by varying the recovery pattern, elevated levels of blood lactate exert no demonstrable effect on maximal effort performance of 5-min duration.


Evidence for increased intrathoracic fluid volume in man at high altitude. To determine if subclinical pulmonary edema occurs commonly at high altitude, 25 soldiers participated in two consecutive 72-h field exercises, the first at low altitude (200-875 m) and the second at high altitude (3,000-4,300 m). Various aspects of ventilatory function and pulmonary mechanics were measured at 0, 36, and 72 h of each exercise. Based on physical examination and chest radiographs there was no evidence of pulmonary edema at high altitude. There was, however, an immediate and sustained decrease in vital capacity and transthoracic electrical impedance as well as a clockwise rotation of the transpulmonary pressure-volume curve. In contrast, closing capacity and residual volume did not change immediately upon arrival at high altitude but did increase later during the exposure. These observations are consistent with an abrupt increase in thoracic intravascular fluid volume upon arrival at high altitude followed by a more gradual increase in extravascular fluid volume in the peribronchial spaces of dependent lung regions.


Meniere's disease: clinical course, auditory findings, and hearing aid fitting. Results of a five-year longitudinal study of Meniere's disease in 95 patients is presented. Tests utilized in diagnosis and in determining specific etiology are described. Clinical treatment for patients with Meniere's disease symptoms is discussed. Auditory test results for 101 ears are analyzed. The fluctuating nature of the hearing loss, the poor discrimination for speech, and the limited tolerance for amplification because of the narrow dynamic range present significant problems in utilization of hearing aids for patients with Meniere's disease. A practical approach is suggested for the fitting of hearing aids for these patients.


Speech discrimination in children: auditory and auditory/visual processing with binaural and monaural presentation. The Word Intelligibility by Picture Identification test was recorded with electret microphones inserted at the ear canals of a child listener. This recording paradigm has been shown to preserve binaural cues. Thirty normal-hearing children (ages 6 to 14) responded to binaural and monaural stimulation under auditory and auditory/visual presentation at six signal-to-noise (S/N) ratios (varying from +3 to -12 dB). At the higher and lower S/N ratios, the binaural advantage was minimized. For the auditory alone mode, the largest mean difference of 21% intelligibility improvement from monaural to binaural presentations occurred at -6 dB S/N, whereas in the auditory/visual mode, an intelligibility improvement of 20.8% occurred at -9 dB S/N. Implications for binaural amplification for the hearing impaired who operate on minimal residual hearing follow from the results of this study.


Exponential analysis of elastic recoil and aging in healthy males and females. To examine the effects of aging on the elasticity of the lungs a single exponential function (V = A - B exp (-KP)), where V is lung volume, P is recoil pressure, and A, B, and K are constants) and a fourth-order polynomial were fitted to the static pressure-volume data from 124 healthy nonsmokers (83 males). K, the index of compliance, was independent of sex and increased with age. B/A and recoil pressures at various lung volumes were higher in males than females, but decreases with age were similar in both sexes. Static compliance (expressed as percent of total lung capacity/cmH2O), derived from the polynomial expression, was the same in males and females and increased with age. The results show that the lungs of males and females have the same intrinsic elasticity, and differences in recoil pressure depend on differences in lung size and in maximum distending forces. Loss of elasticity with age is consistent with an increase in the unstressed dimensions of alveoli and a decrease in their elastic fibers.


Loudness and the acoustic reflex: cochlear-impaired listeners. The relationships among most comfortable listening level (MCL), loudness discomfort level, and the acoustic reflex (AR) to speech were studied on cochlear-impaired listeners using earphones and sound field conditions. Recorded sentence materials were presented monaurally in quiet and in the sound field in the presence of 55 dB SPL cafeteria noise. Both unaided and aided sound field testing were done. The results indicated that the MCL and AR fell at approximately the same intensities under all test conditions, whereas the LDL occurred at approximately 18 dB higher intensity. The MCL was elevated by the presence of noise, whereas the AR remained invariant. Also, the AR occurred below the level predicted by the loudness function. The results tend to indicate that although the AR is highly correlated with MCL in cochlear-impaired listeners a cause and effect relationship may not exist.


Effect of lung surface tension on bronchial collapsibility in excised dog lungs. Bronchial collapsibilities were studied in air- and saline-filled excised dog lungs. The intrapulmonary bronchi were isolated from the rest of the lung parenchyma with beads placed at their tributary bronchi as described previously by Takishima et al. (J. Appl. Physiol. 38: 875-881, 1975). Pressure-volume relations of the isolated bronchi were obtained while lung volume (VL) was kept constant. When lung recoil pressure (PL) was reduced by filling the lung with saline at a given VL, bronchial areas were smaller and bronchial collapsibilities were larger than in the air-filled lung. When bronchial areas and bronchial collapsibilities in air- and saline-filled lungs were compared at a given PL, they were approximately identical. We concluded that bronchial areas and collapsibilities were primarily determined by PL rather than VL, and lung surface tension itself made bronchial collapsibility equal to or even less than the degree of collapsibility due to forces applied from surrounding lung tissues that distended the bronchi.


Metabolic adrenergic changes during submaximal exercise and in the recovery period in man. The urinary excretion of dihydroxyphenylalanine (DOPA), catecholamines (CA) [dopamine (DA), norepinephrine (NE), and epinephrine (e)], their 3-O-methylated derivatives [3-O-methyldopamine (3-MT), normetanephrine (NMN), and metanephrine (MN)], and their deaminated metabolites [dihydroxyphenylacetic acid (DOPAC) and vanilmandelic acid (VMA)] was studied in six healthy men, at rest during short-term (15 min) or exhaustive submaximal exercise, and in the 2-h postexercise recovery period. During short-term exercise only NE and VMA excretions increased, whereas in postexercise period only DA output was enhanced. Exhaustive muscular work induced a rise in NE and E excretion during the test, and an increase in DA, NE, and NMN urinary levels during postexercise recovery, while the output of deaminated metabolites was unaltered. It is concluded that both release and synthesis of CA are stimulated by submaximal exercise, which induces, in addition to NE, a specific release of DA. A possible role of NE in lipid mobilization during recovery from exhaustive muscular work is evoked. The origin and role of released DA are also discussed.


An acoustic reflex technique of establishing hearing aid settings. An acoustic reflex method of establishing hearing aid gain settings for most comfortable loudness was tested. Forty hearing-aid users were examined to determine relationships among MCL, loudness discomfort level, and the contralateral acoustic reflex to speech, under unaided and aided conditions. Results indicate that a simple 2-part rule results in amplification to most comfortable loudness for 76% of subjects. Implications for establishing hearing aid saturation sound pressure level settings are discussed.


Selected lobar injury after infusion of oleic acid. A model of respiratory distress has been developed using sheep in which an isolated lobar injury is induced by infusion of oleic acid into a selected lobar artery. The directed insult permits acute and chronic phase study without the requirement of intensive pulmonary support. One hour after selective lobar injury the affected pulmonary venous oxygenation (Ppvo2) was reduced from greater than 310 to 66-90 Torr. Ppvo2 was most impaired at 48 h (40-55 Torr), but showed improvement by 96 h postinjury. Radionuclide estimates of lobar ventilation and perfusion demonstrated an initial fall in ventilation by 51% and corresponding 41% reduction in perfusion. By 24 h the depression of perfusion matched that of ventilation. Sequential light and scanning electron microscopy demonstrated the presence of a nonhomogeneous injury with areas of both complete parenchymal replacement by fibrous tissue and those with minimal architectural distortion. The selective injury model offers a useful methodology for the evaluation of the effects of various agents on the acute and chronic response of the lung to injury.


Temperature gradients in pigs during whole-body hyperthermia at 42 degrees C. Temperature was simultaneously measured by thermistors in multiple deep-body and peripheral sites in adult pigs heated continuously at 42 degrees C (rectal) and above for 4-24 h. During hyperthermia, the relations between different body temperatures were maintained and up to 1.0 degrees C separated temperature measurements at sites such as liver and bone marrow. These persistent temperature gradients must be borne in mind when evaluating tumor response in patients subjected to whole-body heating for disseminated cancer. Temperatures recorded by rectal, deep esophageal, or tympanic membrane sensors provided a reliable index of core temperature (including brain temperature) under equilibrium conditions at 42 degrees C, but only esophageal and tympanic sensors could safely be used to monitor the induction phase of hyperthermia and the adjustive changes in body-heat content required to stabilize core temperature during sustained hyperthermia. Pigs withstood repeated heating at 42 degrees C for 6 h, and recovered rapidly, but died after 24 h of hyperthermia. Pigs subjected to unrestrained heating died at 45 degrees C (esophagus).


Effects of contusion and flail chest on pulmonary perfusion and oxygen exchange. Localized pulmonary contusions were produced in the right lower lobes (RLL) of 12 anesthetized ventilated dogs, 6 of which had a flail segment in the chest wall over the RLL. Pulmonary oxygen exchange during ventilation with air and oxygen, and the lobar distribution of pulmonary perfusion by radioactive microsphere techniques were measured before and 3 h after contusion, and again after thoracotomy. These were compared to 12 noncontused dogs, 6 of which had a flail segment. Contusion produced an average decrease of 20 Torr in Pao2 during air breathing and an average increase in Qs/Qt of less than 5%, surprisingly small given the doubled weight and average 44% shunt calculated in the contused lobe after thoracotomy. No significant effect of flail or thoracotomy was found, indicating that the presence of an intact chest wall and lung-chest wall interdependence was not a major factor preventing a larger increase in intact whole-animal shunt of contused dogs. Rather, the small effect of this severe lobar injury on whole-animal shunt was due to a 30% decrease in RLL relative perfusion. This reduction was demonstrated to be localized to a smaller hemorrhagic subsection of the contused lobe.


Plasma water shifts during thermal dehydration. Changes in body water compartments during acute dehydration before and after acclimation to heat and the role of plasma proteins in body fluid dynamics were studied in the rat. Compartment volumes, plasma and interstitial protein concentrations, and colloid osmotic pressures (COP) were measured in anesthetized (with thiopental sodium) and, if necessary, nephrectomized rats. Albumin outfluxes, total protein mass (TPM), and total albumin mass (TAM) were calculated. Nonacclimated rats conserved plasma volume (PV) as long as dehydration did not exceed 15-16% body weight loss (18.6% total body water loss). This was associated with decreased albumin outflux, elevated plasma COP, and reduced subcutaneous COP. When water loss reached 25,5%, PV and extracellular fluid volume decreased by 45 and 34%, respectively. Albumin outflux recovered, TPM and TAM decreased, and plasma COP remained high. In acclimated dehydrated rats PV remained unchanged, albumin outflux decreased, TPM and COP increased, and interstitial COP decreased. Most of the water loss was intracellular in origin. It was concluded that PV changes during dehydration are related to changes in plasma protein distribution. PV conservation rate is different in rats as compared to desert PV conservers.


Ventilation-perfusion relationship in young healthy awake and anesthetized-paralyzed man. Distributions of ventilation and perfusion relative to Va/Q were determined in seven young healthy volunteers (24-33 yr) while they were either in the supine or right lateral decubitus position. The subjects were studied first awake and then while anesthetized-paralyzed and breathing 30% oxygen and again while breathing 100% oxygen. In the awake state, no statistically significant differences were observed in the distribution of ventilation and perfusion relative to Va/Q between the supine and right lateral decubitus positions or on changing the inspired oxygen concentrations. After induction of anesthesia-paralysis, Va/Q mismatching increased significantly but only small right-to-left intrapulmonary shunts developed. Ventilating the lungs with 100% oxygen further increased the dispersion of blood flow distribution during anesthesia-paralysis; lung units with low Va/Q or right-to-left intrapulmonary shunts (or both) developed. With induction of anesthesia-paralysis and intubation of the trachea, the anatomic dead space was decreased and the alveolar dead space increased.


Aerobic and glycolytic metabolism in arm exercise. Eight kayakers (K) and 3 sedentary subjects (S) performed arm cranking and pedaling while erect or supine at each of several work loads from submaximal to the highest they could sustain for 2 min and for intervals varying from 10 s to 5 min. From measurements of VO2 and blood lactate concentration, the aerobic and glycolytic energy release in arm work was assessed. For steady-state aerobic work all subjects had a mechanical efficiency averaging 0.24 independent of posture or exercise mode. Per unit fat-free limb volume, arm VO2max of group K was 1.5-fold that of group S, whereas leg VO2max was the same in each group. Compared to group S, glycolytic arm work in group K was characterized by: 1) higher thresholds for release of lactate at the onset of submaximal work, 2) lower blood lactate concentrations during comparable absolute or relative submaximal work, 3) higher conventional anaerobic thresholds for absolute, but not relative work loads, 4) higher maximal rates of lactate release, and 5) the same maximal blood lactate concentrations. Measurement of the early lactate threshold, which occurred at considerably lower arm work loads than did anaerobic threshold, but which was greatly increased by specific muscle training, may provide a simple, sensitive, and nontraumatic evaluation of muscle training.


Influence of skin temperature on sweating and aerobic performance during severe work. Two male subjects were measured over a range of work intensities at dry-bulb temperature (Tdb) = 21 degrees C (relative humidity, rh less than 50%) and at approximately 65 and 85% VO2max for 1 h at Tdb at 5,10,15,21, and 25 degrees C with high convective airflow (2.5-5 m/s). The results showed that mean skin temperature (Tsk) was related to Tdb and unaffected by rh over the range studied. Tsk was dependent on the relative work load and was 2.5 degrees C lower at 85% than 65% VO2max in the cooler environments. During submaximal work the relative sweat rate (Msw expressed as %Mse, max) was a linear function of rectal temperature (Tre) and Tsk for each subject and thus %Msw, max could be predicted from these two variables with a standard deviation of +/- 12%. For a given Tsk, Tre appeared to rise to meet the requirement of heat loss by stimulating set %Msw response. However, during severe work (85% VO2max) this mechanism appeared to become saturated, Tre (except for a very narrow prescriptive range) was dependent on Tdb. These results suggest that under moderate environmental conditions the maximal aerobic and evaporative (cooling) power outputs of an individual are closely matched and only during extremely hard work does thermoregulation become passive and effectively physical (rather than physiological) in nature.


Effects of specific muscle training on VO2 on-response and early blood lactate. The relationship between half time of the O2 uptake on-response (t1/2 VO2on, seconds) and early blood lactate accumulation (delta Lab, mmol.1(-1) at the onset of submaximal arm and/or leg exercise was the object of a cross-sectional study of sedentary subjects (S,n = 3), and kayakers (K, n = 8), and of a longitudinal study on 11 untrained subjects of specific arm vs. leg training. In supine arm cranking (W = 125 watts) S had an average t1/2 VO2on of 82 s and a delta Aab of 9.2 mmol.1(-1) compared to 47 +/- 7 s and 4 +/- 1.4 mmol.1(-1), respectively, for K. In longitudinal trainees shorter t1/2 VO2on was accompanied by lower Lab for the trained limbs. Specific limb conditioning in swimmers and runners resulted in shorter t1/2 VO2on. A linear relationship was observed between delta Lab and t1/2 VO2on having an intercept on the time axis at congruent to 20 s and a slope proportional to muscle mass. Trained muscles were grouped closest to the intercept indicating local acceleration of the rate of O2 transfer approaching the t1/2 VO2on for isolated perfused muscle at the onset of work. Since t1/2 VO2on, we conclude that factors distal to the capillary are specifically involved in the local training response.


Ventilatory responses to elastic loading at constant PACO2 hypercapnic hyperpnea. Elastic loads of 9 cmH2O/1 were suddenly applied to the external airways of four normal human subjects during hypercapnic hyperpnea of 20-32 1/min using a closed-circuit breathing apparatus that permitted alveolar carbon dioxide pressure (PACO2) to be held nearly constant in spite of loading induced changes in ventilation. Transient depression of minute ventilation (V) and mean inspiratory flow (VT/TI) was observed immediately on loading; both these variables increased progressively to steady levels less than control without significant changes in alveolar chemistry. Two subjects increased VT (volume compensators) whereas the other two chose to increase f (frequency compensators). The net result in V and VT/TI compensation was not different between these groups. Load removal always resulted in an overshooting response of V lasting for several breaths and due entirely to an overshoot in VT because f transiently fell to or below control at once. Elastic loading always resulted in a steeper plot of V-VT in the steady state; in three of the subjects, the transition to this steeper line was immediate. The steady-state responses were qualitatively though not quantitatively consistent with pattern adaptation appropriate to minimize the work-rate of breathing.


Lipid metabolism in skeletal muscle of endurance-trained males and females. Bipsies were obtained from the gastrocnemius muscle of 13 male and 12 female distance runners and analyzed for [14C]palmitoyl-CoA oxidation, fiber composition, and the activities of selected enzymes. The male and female runners were similar in terms of maximal oxygen uptake (VO2max), training mileage, fiber compositions, and data collected during a 60-min treadmill run at 70% VO2max. Muscle succinate dehydrogenase and carnitine palmitoyl transferase activities were, however, significantly greater (P less than 0.05) in the male than in female runners. In addition, the male runners' muscle also showed a greater capacity to oxidize palmitoyl CoA. Little relationship, however, was found between muscle lipid metabolism, enzyme activities, and the calculated (respiratory exchange) fraction of energy derived from fat during 60 min of running at 70% VO2max. Although these data support the concept that endurance training (80-115 km/wk) markedly enhances the capacity of muscles to metabolize fats, the factors that regulate the usage of lipids during prolonged exercise do not appear to be limited by the capacity of the fibers to oxidize fatty acids, as determined by in vitro measurements.


Increased lung lymph transport without heart failure after coronary ligation in sheep. Pulmonary edema frequently accompanies acute myocardial infarction (MI). We measured pulmonary arterial (PAP), left atrial (LAP), and aortic pressures (AP),lung lymph flow (QL), and clearance of total serum protein and each of eight protein fractions in five anesthetized sheep before and after coronary artery ligation. After a stable base line of 1 h, ligation produced significant increases in LAP, QL, and clearance of total protein and four protein fractions, but no significant changes in PAP, AP, or lymph-to-plasma total protein concentration ratio (CSL/CSP). Variables returned to pre-MI levels within 2 h after occlusion. The ratio of wet to dry lung weight measured 2 h after ligation was within normal limits. Two sheep in which the time course of postligation LAP was duplicated by left atrial balloon inflation showed no change in QL. The QL changes seen cannot be caused by LAP increase alone without substantial decrease in CSL/CSP. Increased QL with high CSL/CSP is typical of increased lung vascular permeability, which is a plausible explanation of our results.


Plasma volume changes during rest and exercise in different postures in a hot humid environment. Plasma volume shifts were investigated in five male subjects who rested and exercised in the upright, low-sit, and supine postures in a hot humid environment (49.5 degrees C, 28.9 Torr). The resting and exercise periods were each 45 min in duration. Weight losses during rest were 0.3% with an additional weight loss of 1.1% during exercise. During exercise subjects worked at either 360 or 540 kpm.min-1 in each of three postures. Each experiment was preceded by a 30-min control period in the supine posture at an ambient temperature of 22 degrees C. At rest plasma volume was reduced 17.3% in the upright, 9.0% in the low-sit, and 2.2% in the supine postures (using the end of the supine rest as the zero reference point). Supine exercise resulted in a plasma volume decrease of 11%, the low-sit 7.1%, and the upright 2.7%. The total reduction in plasma volume during the rest and exercise period was 20% in the upright, 16.1% in the low-sit, and 13.3% in the supine. No significant differences in plasma volume shifts were observed between the high and low work loads. The results indicate that the plasma volume shifts observed during rest and exercise in the heat are qualitatively similar to those observed in a cool environment.


Tremor and somatosensory studies during chamber He-O2 compressions to 13.1, 25.2, 37.3, and 49.4 ATA. Comparison was made between intentional and postural tremor amplitudes with a 2-to 50-Hz bandwidth in four men rapidly compressed from surface to 13.1, 25.2, and 37.3 ATA in 4 h while breathing helium-oxygen mixtures (Predictive Studies IV, University of Pennsylvania). Excursions with compression rates of 20 and 40 ft/min were then made to 49.4 ATA on exposure days 2 and 3, returning to saturation at 37.3 ATA for 6 additional days. During compression from 25.2 to 37.3 ATA, there were increases in tremor amplitudes for both intentional and postural tremor in the 3-to 7-Hz and 8- to 12-Hz ranges. Both types of tremor showed increases in amplitudes at 49.4 ATA on exposure days 2 and 3. Amplitude changes in postural tremor, which occurred only on the fastest compression to 49.4 ATA, were less evident than those in intentional tremor during the remaining dive profile, and adaptation to pressure exposure could be defined by day 8. Intentional tremors did not show adaptation at pressure.


Hypothermia induced by chlorpromazine or L-tryptophan: effects on treadmill performance in the heat. To study the effects of preinduced hypothermia on the physiological and thermoregulatory responses to exercise in the heat rats were intravenously administered either 100 micrograms of chlorpromazine (CPZ) or 200 mg/kg of L-tryptophan (L-Trp) under restraint in a cold (4 degrees C) environment. When rectal temperatures (Tre) reached 32-33 degrees C the rats were removed to a hot environment (35 degrees C) where they ran on a level treadmill (9.14 m/min) to hyperthermic exhaustion (Tre, 42.5-43 degrees C). Both CPZ and L-trp hypothermia was effective in increasing significantly (P less than 0.001) the time to hyperthermic exhaustion. However, the maximal Tre and skin temperatures (Tsk) attained were unaffected by either treatment. When the rats exercised on the treadmill, increments (degrees C/min) in Tre and Tsk were significantly (P less than 0.02, minimal) greater for the initially hypothermic animals compared to normothermic controls. Cooling rates were unaffected by either treatment. We concluded from these studies that, although preinduced hypothermia is extremely effective in prolonging the time to hyperthermic exhaustion, no additional beneficial thermoregulatory responses accrued as a result of this treatment.


Respiratory and cardiovascular responses to exercise in the duck. Adult White Pekin ducks were exercised for 20 min on a treadmill (3 degrees incline) at two speeds: 0.9 and 1.47 km/h. Each exercise period was followed by a 90-min rest. Heart rate and systolic and diastolic blood pressure increased significantly during each exercise period. During exercise, tidal volume decreased and respiratory frequency increased. Minute ventilation markedly increased at the onset of exercise and continued to increase throughout, whereas clavicular air sac PCO2 (PCSCO2) decreased. Both PACO2 and PVCO2 decreased as the running speed increased. pHv decreased at the onset of exercise, but returned to near resting values by the end of an exercise period. During either exercise period pHa did not significantly change from control values. PAO2 exhibited significant increases at both exercise speeds. Both arterial and mixed venous plasma [HCO3-] decreased significantly with each exercise period. Body temperature increased 1-2 degrees C during each run. Because the increased ventilation produced a reduction in PaCO2 and Pcsco2, it is unlikely that peripheral or central CO2 receptors were responsible for the ventilatory drive: that drive may result from hyperthermia or activity of certain muscle afferents.


Changes in heart rate associated with high-pressure convulsions in rodents. The effect of compression in heliox atmospheres on heart rate in mice and in rats has been explored. In the absence of high-pressure neurological syndrome (NPNS) convulsions, the general relations between heart rate and pressure in mice from 14 days old to adulthood, as well as in 6- to 8-day-old rats, resemble each other, and also the results reported by others for liquid-breathing mice. Rats, 29 days old and adult, are different in that little bradycardia is observed. Type I (clonic) HPNS seizures are not associated with any additional changes in heart rate. Type II (tonic) seizures are invariably associated with profound transient bradycardia, recovery from which begins about the time the tonic seizure phase ends. The seizure-associated bradycardia can be abolished by atropine pretreatment. Data concerning relation of seizure-associated mortality, drug effects, and age and species differences are presented. The bearing of the results on the questions of seizure types in different species, neuroanatomical bases for HPNS seizures, and high-pressure death are discussed.


Alveolar epithelium transport of albumin and sucrose: concentration difference effect. Isolated Ringer-perfused rabbit lungs were used to study albumin and sucrose transport across the blood-gas barrier. Lungs were filled to about 20% total lung capacity (TLC) ith Ringer solution containing radioactive albumin and sucrose, and their rate of appearance in the recirculating perfusate was monitored. From this the product permeability x area (PA) was calculated. In the middle of the 180-min experiments, some alveolar fluid was removed. In control experiments, the same fluid was reinstilled, in other experiments new fluid with higher test molecule concentrations was infused. In all experiments the results for both molecules were similar: PA for the second half of the experiment was 80% of that in the first half. The reduction was probably due to a decrease in exchange area. We thus find the albumin and sucrose permeabilities to be proportional to their concentration difference. In addition, the PA for sucrose was roughly four times that of albumin. These results can possibly be explained by a two-compartment model with two parallel pathways across the alveolar epithelium. One pathway would be small pores, whereas the other would involve a bulk flow or pinocytosis process.


Radiographic comparison of human lung shape during normal gravity and weightlessness. Human lung shape was measured during zero gravity (0 G) to decide whether the normal vertical regional differences in ventilation are due directly to distortion of the elastic lung by its own weight, or instead, due indirectly to the effect of gravity on the shape of the rib cage and diaphragm. This was important because we previously established that weightlessness virtually abolishes the normal topographical inequality of ventilation (J. Appl. Physiol.: Respirat. Environ. Exercise Physiol. 45: 987-998, 1978). Chest radiographs were made after 10 s of a weightless flight trajectory aboard a NASA-Ames Research Center Learjet in both posterior-anterior and left lateral projections on five seated volunteers at residual volume, functional residual capacity, and total lung capacity. Lung shape was assessed by measuring lung heights and widths in upper, middle, and lower lung regions. We found no significant differences between any of the normal gravity (1 G) and o G measurements, although there was a slight tendency for the lung to become shorter and wider at o G (mean changes generally less than 3% or about 0.5 cm). By contrast, Grassino et al. (J. Appl. Physiol. 39: 997-1003, 1975) found no change in the vertical distribution of ventilation after voluntarily changing lung dimensions by more than 1 cm by moving the abdomen in or out. We conclude that gravity produces the topographical distribution of ventilation in the upright human lung by distorting the elastic lung tissue within the chest rather than by altering the shape of the rib cage and diaphragm.


Calculated deposition of inhaled particles in the airway generations of normal subjects. Detailed regional deposition of inhaled particles in the human lung is calculated for individual airway generations. The calculations are based on Landahl's deposition model as applied to the morphometric lung model of Weibel. We consider primarily deposition patterns of iron oxide particles with diameters ranging between 1 and 10 micrometers, but we also calculate patterns of deposition for bis(2-ethylhexyl) sebacate particles with diameters as small as 0.2 micrometers. We obtain good agreement between predicted values and observed values for alveolar retention of inhaled iron oxide particles with 64 and 20% of total deposition predicted to occur in nonciliated airways for 2- and 5-micrometer particles, respectively. This is compared with 48 +/- 9 and 27 +/- 10% for the measured values. Calculated values for total lung deposition of small bis(2-ethylhexyl) sebacate particles agree well with experimental data. The calculations show a minimum in deposition occurring for particle diameters of 0.5 micrometers, which is in agreement with observations. A calculation of surface concentration of deposited 7.9-micrometer aerodynamic particles reveals a very large concentration occurring at airway generation four. This observation is considered in light of observations that bronchial carcinomas occur in this vicinity of the lung.


Airway closure during anesthesia: a comparison between resident-gas and argon-bolus techniques. Airway closure was measured in awake and then anesthetized supine healthy subjects with the argon-bolus and the resident-gas (nitrogen) techniques simultaneously. The preinspiratory lung volume for the closing volume maneuver was varied from residual volume to closing capacity (CC). Comparative measurements were also performed in the upright and supine positions in awake subjects. Closing volume (CV) was consistently larger with the bolus technique in supine subjects both when awake and when anesthetized (difference between methods 0.1--0.2 l, P less than 0.01), whereas no difference between the methods was noted in upright subjects. The lower "nitrogen CV" in supine subjects may be due to a shorter vertical lung height with a smaller range of nitrogen concentrations, resulting in a less abrupt onset of phase IV (taken to indicate CV). CV was not significantly affected by the preinspiratory lung volume with either technique, and CC was unchanged when anesthesia was instituted. Functional residual capacity (FRC) was reduced with anesthesia (mean reduction: 0.6 l, P less than 0.01) and FRC-CC became negative in all subjects with either technique. This implies intermittent or continuous airway closure during anesthesia and the possibility of increased venous admixture.