[Determination of phosphonic acids in ruminal fluid]. A technique has been worked out for determining amino alkyl phosphonic acids in ruminal fluid by using methods of hydrolysis, partition of the phosphonic acid on a cation exchange column and ashing of the eluate. After evaporation to total dryness the phosphonic acids were determined as phosphates. The amounts of acid found in the ruminal fluid of goats varied between 0.4 and 1.1 muMol/ml. In view of the fact that these acids are microbial compounds it will appear that any change in the amount of compounds produced in the rumen would indicate changes in the concentration of the microbial mass in the rumen.


[Influence of milk-fat substitute feeding on the metabolism in calves]. Investigations were made to study the effect of milk fat substitutes ("Laktin", "TZS-60") on the metabolism of 3 and 5-weeks-old calves. "Laktin" is prepared from lard and hydrogenated soya and fish oil; additionally, it contains lecithin, monoglycerides, antioxidants, vitamins and antibiotics. "TSZ-60" is a preparation containing starch and colloidal silicic acid as carrier material mixed with 60% of coarsely powdered fat (particle sizes ranging from 50 to 200 mum), which in turn, is supplemented with vitamins and antibiotics. The kinds of "Laktin" used in the present trial contained 95%, 58%-98% or 90% of fat while "TSZ-60" contained 59.4%. Both the 3-weeks-old and the 5-weeks-old calves digested the "Laktin" fat more efficiently than the kind of fat contained in "TSZ-60" ("Laktin": 94.3% to 97.3% of fat; "TSZ-60" 71.8% to 90.5%). As a consequence of this, the "Laktin"-fed calves exhibited a higher rate of nitrogen utilization and nitrogen retention. According to the results obtained in the present trial "Laktin" should be given in daily doses of 219 g (an amount corresponding to 7 litres of milk with a milk fat content of 3.13%) while "TSZ-60" should be fed in daily amounts of 245 g (corresponding to 7 litres of milk with a milk fat content of 2.1%). Higher doses ("Laktin": 323 g/day: "TSZ-60" 335 g/day) would have a detrimental effect on the metabolism of the calves. Apart from this, it was not found that higher doses would help to reduce the protein consumption of the animals.


[Substitution of protein feed through lysine-supplemented high-protein wheat during the rearing and laying period of hens. 2. Effect of graded lysine doses on food consumption and the rate of weight gain in young hens]. In a feeding trial 1920 young hens received rations consisting mainly of high-protein wheat with or without additions of lysine or methionine (table 1) and a control ration. The five rations contained 0.77%, 0,59%, 0,61%, 0,54% of 0,46% lysine. In the period between the 9th and 20th week of experiment the hens receiving less lysine consumed less food in the beginning but more food towards the end of this experimental period (12th to 16th week of experiment). The lower energy content of the control diet produced a higher rate of food consumption. Variations in the lysine supply in general produced only slight differences in feed consumption and weight gain in the rearing period of the hens, whereas a compensatory effect was observed with regard to the growth rate of the birds. Despite the balanced crude protein consumption of the birds a positive linear regression of crude protein utilization was calculated for the percantege crude protein retention (y) as depending upon the lysine content of the ration (x) (y = 11.34 + 19,61x; B = 0.93). The wheat protein could be improved by lysine supplements.


[Methionine metabolism. 2. Biochemical and histological studies in rats]. Male rats weighing 100 g were used in a 19-day trial. The rats received diets containing varying proportions of methionine. Their absolute liver weight was lower, due to the high methionine levels, than that of the animals fed optimum rations, whereas the relative liver weight was found to be lower only in the pair-fed group. No essential differences were observed between the levels of dry matter, protein, and fat. Glycogen levels were found to be lowered only in cases when high methionine doses were administered. Pathologically low levels of glycogen were found in animals of the pair-fed group. High methionine consumption reduced the percentages of 12 glucogenetic amino acids in the liver. This, in turn, suggests an increased rate of glucose formation from amino acids, a process which was not observed in animals of the pair-fed group. High methionine doses produced a condition of hyperglycaemia, while in the pair-fed group hypoglycaemia was observed. The highest rate of secretion of thyroid hormones was found in animals receiving the optimum ration; a lower rate of secretion was observed in the animals consuming less or more methionine. In animals receiving high methionine levels the rate of hormone secretion decreased in a stepwise manner with increasing methionine supplementation. Only the highest methionine doses (5,3%) were found to have a negative effect on the maximum rate of iodine incorporation into the thyroid gland. These findings were also substantiated by histological investigations because a true pathological picture was only found in histological sections of thyroid tissue from animals fed the highest methionine doses (5,3%) The thyroid tissue of these animals consisted predominantly of small glandular alveoli whose colloid was slightly coloured. The epithelial cells of these alveoli were degenerated; some cases of liver cell disintegration and, more rarely, cellular necrosis were noted.


[Nitrogen metabolism of broilers fed N-15 labeled wheat. 3. Blood, liver, spleen, thymus, kidney, brain, pancreas, labile N reservoir]. Studies on the N metabolism of 4-week-old male broilers fed 15N Labelled wheat revealed a close correlation existing between the levels of 15N concentrations in the small intestine and in the plasma NPN fraction of the blood. The highest level of excess 15Natom0/0 in plasma proteins was noted as late as 20-30 hrs after administration of the last tracer dose. The mean life time of plasma proteins in broilers is less than 2.0 days. The rapid and statistically significant decrease of 15N frequency in the liver, spleen, thymus, and kidneys in the period from 12 hrs after withdrawal of the last 15N dose until the end of the trial reflects the intensity of N turnover in these organs. In the period from 6 hrs to 12 hrs after the last N intake the mean quantities of N in the liver, small intestine and kidneys decreased by 18%, 29%, 26% and 16%. The quantity of N accumulated in these organs after food intake is gradually released into the organism.


[Protein utilization in calves during different periods of liquid feed fattening]. 2 groups of male calves (Braunvieh) each comprising 5 animals with liveweights, at the day of slaughtering, of 58 kg, 99 kg and 155 kg were used in a trial that was carried out to obtain data on the utilization of dry matter, crude protein, crude fat and ash in the bipartite feeding of calves. The nutrient content of the animals was determined by total body analysis. The following values for nutrient retention were obtained in comparative slaughtering trials by using differentiation techniques. No significant differences between the two fattening periods were observed concerning the utilization of total dry matter in the milk substitutes. About 24% of the dietary dry matter were retained. The mean value for the utilization of dietary fat during the whole period of fattening was found to be about 55% provided, the fat was not used as energy source to meet maintenance requirements. 49% of the milk proteins were utilized for both retention and maintenance in the first period of fattening and 55% during the second period. Differences between the two periods showed no consistent trend. In view of the fact that for all animals used in the trial digestibility was taken to be 95% the utilization coefficients for the digested crude protein were higher by about 3% compared with the figures for crude protein. After subtraction of maintenance needs it was found that, on an average, 63% of the residual amount of digested protein available over the whole fattening period were retained in the body. 55% to 57% of the retained protein were deposited in those parts of the body of the animals that are used for human nutrition. It is for this reason that in the first half of the fattening period only 29.8% of the ingested dietary proteins were retained in the edible cuts of the animal body, as compared with 30.4% during the second half of the fattening period.


[Determination of the true digestibility of amino acids in pigs]. Pigs of varying liveweight received protein-free diets in a trial made to establish the excretion levels of endogenic intestinal nitrogen and endogenic intestinal amino acids. The highest excretion rates of endogenic intestinal N and intestinal amino acids per kg of liveweight or per 100 g of dry matter ingested were found in pigs weighing about 10 to 40 kg. The lowest values were abtained in pigs with a liveweight exceeding 40 kg. The levels of endogenic intestinal N and intestinal amino acids are variable quantities. So, true amino acid digestibility data should be determined in pigs weighing more than 40 kg, because in these animals the relation between the intaken of amino acids and the level of endogenic excretion in the faeces is widest and hence, this variable factor would have the least influence on calculations of digestibility data. The data established for the true digestibility of nitrogen and amino acids of barley fed to pigs weighting 10-100 kg were found to be at the same level (with the exception of lysine) when due consideration was given to figures for the excretion of endogenic intestinal N and intestinal amino acids taking into account the liveweight of the animals.


[Effect of zinc deficiency on the digestibility and utilization of nutrients]. Weaned male rats were used in a metabolic trial to investigate the digestibility of dry matter, crude protein, ash and energy, the energy and N balances and the rates of zinc absorption and zinc retention under conditions of zinc deficiency. 2X8 experimental animals were kept in separate metabolism cages for 6 periods each lasting 5 days. The animals received a semisynthetic zinc-deficient diet (casein + starch + sucrose) containing only 1.0 mg Zn per kg of dry matter (zinc-deficient group fed ad libitum) or plus 49 mg Zn per kg of dry matter (pair-fed control group). The mean intake of dry matter was 2-3 g per day/animal. 2.9 g of food were necessary to produce 1 g of weight increase in the deficient animals and 1.4 g in the controls. The rate of apparent zinc absorption was always clearly negative in the Zn-deficient group. In the control group apparent zinc absorption decreased from 60% to 27% in the course of the trial while zinc retention decreased from 51% to 10%. During zinc deficiency the rates of both faecal and absolute renal Zn excretion were found to be greatly reduced. The proportion of renal zinc excretion relative to total excretion averaged 60% in the experimental group as compared to 17% in the controls. No significant differences were found in the digestibility data of gross energy. Nutrient digestibility (%) was significantly reduced under conditions of Zn deficiency (data for the control group given in brackets): 92,6 (94.0) for dry matter; 93,2 (94.1) for organic matter; 93.3 (96.2) for crude protein and 76.6 (90.8) for crude ash. Similarly, N retention data, in Zn-deficient animals, declined from 30.5% to 14.7%, and metabolizable energy decreased from 88.7% to 85.6%. The differences obtained are not sufficient, however, to account for the clearly increased food requirements observed in zinc-deficient animals. Thus, considerable disturbances have to be assumed to occur in the processes of intermediary nutrient utilization.


[Constant level of intestinal amino acids as a function of the composition of same]. The present study was conducted with pigs. It was designed to investigate whether extreme amino acid proportions in the ration would influence the excretion of endogenic amino acids in the faeces. Addition of DL-methionine or L-Lysine produced slight changes in the composition of endogenic intestiornal protein, a fact that was practically of little or no importance for the method of faecal analysis used in determining the true digestibility of amino acids (classical technique).


[Determination of urea in the ruminal fluid of sheep]. Low values for urea were found in samples of ruminal fluid of sheep fed concentrate rations if urea determination was carried out by the urease method. The present paper describes a both simple and sensitive colorimetric method of analysis using diacetyldioxime. The method is suitable for determining urea in coloured solutions such as ruminal fluid or silage extracts.


[Interaction of nickel with iron, copper and zinc]. Studies were carried out investigating the role of nickel as an essential element in the growth of rats. Reduced levels of iron, copper and zinc were found in the liver, spleen and kidneys during Ni deficiency. These findings could be reproduced in 2 generations of 30-day and 50-day-old rats. Reduced rates of Fe storage during Ni deficiency were, in some cases, even noted of the Fe supply was raised to a level of as high as 100 mg Fe per kg of the diet. This accounted for the diminished haemoglobin values, the reduced erythrocyte count and reduced hematocrite found under conditions of Ni deficiency.


[Nitrogen metabolism of broilers fed 15-N labeled wheat. 4. 15-N concentration in muscles and nitrogen utilization]. Broilers were fed 15N labelled wheat and the concentration of the labelled isotope in muscular tissue was determined. A negative correlation was found to exist between the percentage proportion of N in the muscle fractions and the level of 15N frequency established 12 hrs after administration of the labelled ration. Higher rates of tracer incorporation were observed in the muscles of legs and other muscles (predominatly red muscles) than in pectoral muscles (white muscles). The heart was shown to exhibit the lowest N content and the highest level of 15N frequency of all muscle fractions. In view of the fact that some specific difficulties will arise when certain factors (trace elements, vitamins, ergotropic substances, genetic factors) which influence the N metabolism of fattening poultry, are estimated on the basis of the conventional N balance trials the present tracer technique is recommended for use as an alternative method in studies of the kind just described. In the present trial 20% of the wheat N were utilized for the production of meat N in muscular tissue.


[Distribution of radioactivity in the body and rate of incorporation of radioactivity into the tissue proteins of monogastric animals following intravenous injection of tracer amino acids]. The studies were carried out with pigs and rats. The radioactive animo acids (14C leucine and 3H lysine) were administered to the pigs by way of a catheter tube into the jugular vein. Subsequently, the time pattern of the distribution of the specific amino acid radioactivity was followed in the TCE soluble and Tce precipitable fractions of the blood plasma (TCE= trichloro-acetic acid). The radioactive labelling in rats was carried out by injecting 14C leucine into the portal vein. The animals were killed after incorporation periods from 2 to 60 mins, and the levels of specific radioactivity were estimated in the TCE soluble and TCE precipitable fractions of the blood plasma, in the liver and in the skeletal muscles. The experimental results clearly indicated that the specific radioactivity of the tracer amino acids and the rate of incorporation of radioactivity into tissue proteins were greatly influenced by the size of the free amino acid pool within the range of distribution of the tracer. An estimation of the magnitude of the pool of free amino acids within the distribution range of the tracer can be obtained from the curve pattern for the decline of specific radioactivity of the corresponding free amino acid in the blood plasma. This pool exhibits a high rate of turnover. In all studies made to evaluate in vivo processes of protein synthesis by use of radioactive tracer amino acids it will be particularly important that consideration should be given to the specific radioactivity of the amino acid in the precursor pool for protein synthesis.


[Concepts of G. A. Shmidt concerning the principles of ecologic embryology and their use in current research]. Under consideration are principle conceptions of G. A. Shmidt on the ecological method in embryology: succession between the compared species, difference in the ecology and organization of adult individuals, distinctions in the course of embryogenesis. Difficulties in a strict observation of all these principles are analyzed in comparative embryological investigations. Possible use of the above principles for studying the intrespecies variability of ontogenetical processes is shown.


Infection of newborn and fetal hamsters induced by inoculation of LuIII parvovirus. The LuIII parvovirus was adapted to the newborn hamster and produced a systemic infection with massive intestinal hemorrhage. Inoculation of pregnant hamsters lead to transplacental infection of the fetuses and abortion. Most fetal deaths were observed in animals inoculated on days 8 and 10 of gestation. Virus was recovered from dead fetuses, placentas, and viable fetuses. Histological lesions were found in the heart, liver, kidney and CNS of infected fetuses.


[Human placental morphology as an index of features of maternal-fetal relationships]. Principle possibilities of the complex evaluation of the mother-fetus exchange were studied by means of morphological investigations of the human placenta in normality, in vesicular mole, late toxicoses, hemolytic disease of newborns and malformations of the fetus. The investigation of the ratio of the villi of different size, deposition of fibrinoid on their surface, the change of the amount of cytotrophoblastic elements, cells of Kaschenko-Hofbauer and the polymerity of the basic substance are of diagnostic value. The authors propose the basal lamina of the placenta to be included into the scheme of the examination of placenta.


[Morphofunctional specialization of tissue components of the mammalian placenta and adaptational value in changes in the rate of their differentiation (evolutionary and clinical aspects)]. It has been shown that in the ontogenesis of human placenta there occur regular changes in the percentage of the villi of various calibre having different interrelationships between the trophoblast, the connective tissue stroma and the fetal vessel. The changes of the number of chorial villi affected by fibrinoid and containing blood vessels under the trophoblast in late toxicoses of women and the anemic syndrom are analyzed (treated and not treated groups of women suffering from different forms of toxicosis were compared). An increased amount of chorial villi having blood vessels under the trophoblast is noted which is a morphofunctional feature of compensatory-adaptational alterations. Possible ecologo-evolutionary approaches to clearing the biological significance of adaptational changes of morphogenesis of the human placenta in pathological pregnancy are shown by the example of the analysis of morphological peculiarities of the placenta of the dolphin.


[Localization of the fluorescent part of the Y-chromosome in nuclei of the chorionic symplast of the human placenta]. The localization of fluorescing Y-chromatin was studied in the nuclei of the chorionic symplast of the mature human placenta in cytological smears and histological sections stained with acrichin-mustard. Its localization within the nucleus and its relationship with nucleoli and nuclear membrane are shown. The significance of studying Y-chromatin in the placenta for population investigations in human cytogenetics and for the establishing of the affiliation of placenta structures is discussed.


[A previously unknown nucleus in the lateral loop of the dolphin brain, its morphologic organization and origin]. An earlier unknown cell formation in the lateral loop of the dolphin brain has been first shown and studied. On the basis of cytoarchitectonical and topographical characteristics its homology with the corresponding nucleus of other mammals has been established. The investigation has brought a substantial correction to the morphology of nuclei of the lateral loop of dolphins since the formation described proved to be a ventral nucleus of the lateral loop while the structure known in the literature under this name represents an intermediate nucleus of the lateral loop of the animals concerned.


[Projections of several intralaminar nuclei of the thalamus to the caudate nucleus in cats]. Direct connections of the central medial, parafascicular and central lateral nuclei of the thalamus with the rostral and caudal parts of the head and the body of the caudate nucleus were studied. The study has revealed that only the central nucleus of the three concerned intralaminar nuclei of the thalamus is projected on the caudate nucleus, head and body. The central medial and parafascicular nucleus of the thalamus does not seem to have direct connections with the caudate nucleus.


[Localization of cells connected with different tropic functions in the hypophysis of the young of Huso huso L. X Acipenser ruthenus L., Chondrostei]. A number of histological and histochemical methods were used in order to detect different secretory cells in the hypophysis of young Huso huso L. x Acipenser ruthenus L., Chondrostei. special attention was given to somatotropic cells. For their detection the following staining methods were used: orange G - acidic red 2C - acidic green G after fixation in the mixture of HgCl2 with formalin. In the dorsal part of the hypophysis having the appearance of vertical folds pressed into the hypophysis from the dorsal side, the cellular elements are represented mainly by somatotropic cells. In the dorso-nasal part the prolactin cells form the follicles. Part of prolactin cells lie between the follicles. Here there are some corticotropic cells. In the ventral part a considerable amount of basophils are found. The anatomic structure of the hypophysis is considered basing on the above data.


[Morphofunctional analysis of the response of the parotid gland to disruption of its sympathetic innervation]. The parotid salivary gland of rats was studied after extirpation of the upper cervical sympathetic ganglion in different time after a single feeding. The gland of non-fed animals served as control. The desympathization of the gland has been shown to result in considerable alterations in the ultrastructure of its acinar cells and less pronounced alterations in the salivary tube cells. The interferometrical study has shown that after desympathization the dry weight of acinar cells, the sparseness of the dry weight figures in different animals and the amplitude of the protein amount fluctuations during the secretion cycle decreased. The obtained data point out that to sustain the structural entity of the organ and its normal functioning the sympathetic innervation of the organ must be kept intact.


[Patterns characterizing different levels of animal organization]. The article deals with features of the regularities characterizing different levels of organization of the animal body. The cell is not only an integrated but also indivisible organic integrity which is due to the  interaction of the nucleus and cytoplasm determining all sides of its vital activity. From this viewpoint the results of experiments on transplantation of the embryo cell nucleus into an enucleated egg of amphibia and the data on somatic hybridization are estimated. All processes of the cell life, their growth, multiplication and differentiation develop within the tissue system and are determined by the regularities of its development. The integrated system of the organism of a multicellular animal unites all the forms of integration of multi-step systemic pattern at different organization levels. Among different categories the systems of tissues and their interaction within the organ are most integrated. The regularities of the tissue development can not be brough to the regularities of the development of the anatomical structure of organs. The integration of cell elements in a tissue system and intertissue relations is the basis of all forms of interdependence in the cell development and the organism structure.


[Ultrastructure and dynamics of the transosomes of the follicular epithelium of avian ovaries]. Specific organelles in follicular cells of the avian ovaries - so called transosomes - are described. Transosomes are formed in the follicular cell cytoplasm under the cytoplasmic membrane and consist of a dense layer 100-150 A in thickness and granules 110-250 A in diameter evenly distributed on its inner surface and containing r-RNA. The main property of transosomes is to move from one follicular cell to another or to an oocyte having separated from numerous processes of follicular cells and being surrounded by two additional membranes. In the ooplasm the transosome takes part in the development of primordial yolk granules. It is supposed that transosomes bring about a transmission of somatic follicular cells to the occyte which is necessary for the initial stages of vitellogenesis.


Ultrastructure of the stroma of nasal polyps: cilia in stromal fibroblasts. Ultrastructural examination of the stroma of simple nasal polyps was shown that there is an edematous framework of fibroblasts with abundant interdigitating cytoplasmic processes, a plexus of inflamed blood vessels, and a mixed infiltrate of active inflammatory cells. Solitary cilia were seen to arise from the stromal mesenchymal cells; no mycoplasma or viral inclusions were present. These features may have a relationship to the pathogenesis of nasal polyps. An immunologically induced liberation of vasoactive amines from mast cells results in increased capillary permeability and a consequent excess of intracellular fluid; the stromal cells attempt to check this expansion by an increase in collagen synthesis.


Lymphocyte response in patients with head and neck cancer: effect of clinical stage and radiotherapy. Ffty-three patients with head and neck cancer tested before radiation treatment to determine numbers of blood lymphocytes and immunologic responses to mitogens of lymphocytes in whole-blood cultures had mean values that were 19% to 26% less than values for healthy individuals. Thirty patients whose disease was in stages III or IV had values similar to those in 23 patients whose disease was in stages I or II. Values for 45 patients tested at end of radiotherapy decreased to about 50% of pretreatment values; however, patients with advanced lesions experienced greater decreases (to 24% to 50%) than patients with localized lesions (to 71% to 84%). Patients with advanced lesions usually received radiation to larger areas than patients with localized lesions; therefore, the extent of decline in laboratory values was most likely dependent on volume of tissue treated.


Prognostic criteria of sudden deafness as deduced by electrocochleography. Electrocochleography was performed at first examination in 34 patients with sudden deafness. Recording was made with the use of the transtympanic needle electrode technique. A notable difference in the electrocochleographic findings was shown between the cases of complete recovery or remarkable improvement and the cases of slight improvement or no change. Electrocochleography may be prognostic of sudden deafness at initial onset.


Subjective and electrophysiologic tests in brain-stem lesions. A battery of subjective and electrophysiologic auditory and vestibular tests were administered to 22 patients with neurologically confirmed brain-stem lesions to investigate the interrelationships between the test results. Acoustic-reflex and simultaneous midplane binaural loudness-balance abnormalities were related to N2 and N3 abnormalities on the brain-stem evoked-response measures. Unilateral abnormalities in low-redundancy speech tests, prolonged auditory reaction times, and reduced loudness growth on the alternate binaural loudness-balance test were related to ipsilateral N4 abnormalities or contralateral N5 abnormalities on the brain-stem evoked-response measures.


The cross-check principle in pediatric audiometry. We discuss a method of pediatric audiologic assessment that employs the "cross-check principle". That is, the results of a single test are cross-checked by an independent test measure. Particularly useful in pediatric evaluations as cross-checks of behavioral test results are impedance audiometry and brain-stem-evoked response audiometry (BSER). We present five cases highlighting the value of the cross-check principle in pediatric audiologic evaluation.


Brief-tone audiometry in pseudohypacusis. Brief-tone audiometry was administered to two groups of listeners. The first group consisted of five sophisticated subjects with normal hearing, who were tested under normal and simulated hearing-loss conditions. The second group consisted of five patients with true pseudohypacusis. Results under simulated and true pseudohypacusic conditions were similar, but were different from those obtained from the normal listeners under normal conditions, which further extends the diagnostic value of brief-tone audiometry.


Mandibular fracture complications.

Mandibular fracture complications. This paper presents the authors' experiences with 111 treated mandibular fractures and 16 cases of complication. Pertinent data on the fresh fractures are given, but the major part of the study deals with cause, diagnosis, and treatment of the complications of mandibular fractures. These are divided into four categories-infection, nonunion, malunion, and temporomandibular joint ankylosis, although only infection and temporomandibular joint ankylosis are included here. Unique mandibular fracture complications are reviewed.


Chromophobe adenoma manifesting as a nasopharyngeal mass. A 64-year-old woman had a sphenoid sinus tumor and nasopharyngeal mass verified to be a nasopharyngeal chromophobe adenoma with no evidence of sellar enlargement or involvement. The possibility that this mass arose from ectopic hypophyseal tissue located in the pharynx is proposed.


The effect of extensive chorioptic mange of the scrotum on reproductive function of the ram. Reproductive function was assessed in 14 stud rams which had been rejected as genitally unsound because of extensive chorioptic mange (Chorioptes bovis) of the scrotum. Severe seminal degeneration was observed in all of these rams. Mean testicular weight of the affected rams was 72.2 +/- 18.4 (S.D.) g, while that of the non-affected control rams was 190.1 +/- 38.2g. The seminiferous tubules of the atrophic testes were severely shrunken and spermatogenic arrest occurred at the spermatogonia or primary spermatocyte stage. Androgenic status and libido as assessed by seminal fructose, seminal vesicle weight, seminal fructose and reaction time were not affected by the disease. The average testicular temperature of 11 rams with extensive scrotal mange and severe testicular atrophy was 0.6 degrees C to 3.1 degrees C (average 1.7 degrees C) higher than that recorded from 11 control rams. The exudative dermatitis did not penetrate the tunica vaginalis sac and had no apparent effect on the general health of the rams. It was concluded that scrotal mange causes testicular degeneration by raising the temperature of the scrotal contents. Four rams that had severe testicular atrophy with complete spermatogenic arrest showed an acceptable level of semen production following treatment of their mange lesions. Recovery of spermatozoal production was also observed following spontaneous cure of chorioptic mange lesions in a ram whose scrotum had become severely thickened and pendulous due to long-standing chrorioptic mange.


The effect of Leptospira hardjo vaccine in a northern Queensland beef herd. In a northern Queensland beef herd where there was serological evidence of L. hardjo infection, lactation failure or wastage between pregnancy diagnosis and branding was 11.9% in animals vaccinated with a single dose of a L. hardjo vaccine and 19.4% in unvaccinated controls. This difference was statistically significant (P less than 0.05). Vaccination caused a significant (P less than 0.05) reduction in rate of lactation failure in heifers but not in other classes of cows.


Helminth control in Queensland beef cattle: comparison of part paddock and whole paddock treatment in the wallum of south eastern Queensland. An increase in the body weight gain of beef calves due to a reduction in the overall larval nematode challenge and a consequent reduction in the host response to infection was observed on fertilised, improved pasturesin the wallum country of south eastern Queensland. Three groups of calves were used. Group 1 consisted of 15 calves and their dams on 20 ha, all receiving monthly injectable tetramisole. Groups 2 and 3 consisted each of 15 calves and dams grazing 40 ha with only the 15 calves of Group 2 receiving monthly tetramisole. The trial concluded after 10 months when the mean body weight gains made by calves of Groups 1, 2 and 3 were 206 kg. 177 kg and 168 kg respectively. These differences proved statistically significant. All heifers from these groups were sold soon after the conclusion of the trial and sale prices of heifers from Group 1 were 11% higher than those from Group 2 and 21% higher than those from Group 3. During this work the predominat parasitic nematode present was cooperia spp H. placei and O. ostertagi were also prevalent species and O.E. radiatum was present in low numbers.


Skeletal response of rats to repeated short-term hyperbaric helium-oxygen exposures. Young male rats were exposed to repeated heliox dives and analyzed for skeletal alterations. Animals were exposed 1, 3, 5, or 7 times to either 1 ATA He-O2 for 12.5 h, or to 5 ATA He-O2 for 4 h and a 8.5 h decompression, or to 5 ATA He-O2 for 4 h and a 1.5 h decompression. In a separate study, 30 rats were exposed 6 times to 5 ATA He-O2 and explosively decompressed. Animals were sacrificed 20 d after the last dive. There were no significant changes in femur wet weight, density, ash weight, length, or mineral content. Plasma calcium, phosphorus, and alkaline phosphatase remained normal. Eighteen of 30 animals survived the six explosive decompressions; however, there were no significant changes in bone. These results indicate that the number and rate of decompressions used in this study have no lasting effect on bone growth and mineral composition in the rat.


Influence of cold or hyperbaric helium-oxygen environments on mouse response to a respiratory viral infection. In investigating the stress effects of chilling (2-3 degrees C) and hypothermia (2-3 degrees C drop in body core temperature mediated by exposure to hyperbaric helium-oxygen atmosphere) on mouse resistance to "influenza," it was noted that these stresses adversely affected the course of pulmonary infection produced by aerosols of the NWS strain of influenza virus. Comparatively, respiratory LD50 values for control animals were about 25 virus plaque-forming units (PFU) with median mortality occurring on day 13. The LD50 values for mice chilled at 2-3 degrees C were about 15 PFU with median mortality on day 7, and for mice exposed to hyperbaric helium, about 12 PFU with median mortality on day 6. Cold or hyperbaric stress impaired interferon production. Impairment was observed at 24 h but not at 12 h post-challenge and persisted for several days until mice became moribund.


Cytochemical investigations of proteins and RNA in spinal motoneurons and neurons of spinal ganglia of the rat after space flight. The content of RNA and cytoplasmic protein was assayed by methods of quantitative cytochemistry in motoneurons of anterior horns of the spinal cord and neurons of spinal ganglia of rats flown for 22 d. It was shown that the 22-d space flight did not change the RNA content in motoneurons of anterior horns of the spinal cord and reduced the RNA content in large neurons of spinal ganglia. The protein content in the cytoplasm of motoneurons and neurons of spinal ganglia was significantly lowered as compared with the control. The RNA content 27 d postflight in motoneurons of anterior horns of the spinal cord was significantly reduced and in neurons of spinal ganglia it did not differ from the control. On the 27th postflight day the protein content in the cytoplasm of motoneurons returned to the preflight level and in the cytoplasm of large neurons of spinal ganglia remained lowered.


Cardiac pathology associated with high sustained +Gz: I. Subendocardial hemorrhage. Adult miniature swine were exposed to various levels and durations of +Gz. After exposure, all swine were euthanized and necropsied. Gross, histologic, and electronmicroscopic observations were made on the heart tissue. Subendocaridal hemorrhage (SEH) was commonly found in the left ventricle, rarely in the right ventricle, and its severity was directly related to : a) level and duration of G exposure, b) heart rate, and c) catecholamine activity. SEH was made more severe with i.v. atropine 4 mg, and prevented with i.v. propranolol 20 mg. Heart hemorrhage was usually limited to the immediate subendocardial region and frequently surrounded Purkinje's fibers. In severe cases, however, hemorrhages penetrated several millimeters into the heart muscle and sometimes penetrated Purkinje's fibers. Restraint of unanesthetized swine in the centrifuge couch, low G-levels, and/or i.v. injections of atropine or epinephrine produced minimal SEH lesions.


Cardiac pathology associated with high sustained +Gz: II. Stress cardiomyopathy. The myocardial pathology of 14 pigs exposed to HSGz stress of 9 and 15, or 3, 7, and 9 Gz was studied; six control pigs were used as comparisons. Four pigs received propranolol prior to centrifugation and four pigs received atropine. Hearts were studied by light and electron microscopy. Myocardium from stressed pigs showed myofibrillar degeneration, pooling of mitochondria, and cell death. Lesions occurred in random cells of the subendocardium and papillary muscles. Purkinje fibers were also involved. Pretreatment with atropine increased the number of dead cells found and propranolol increased the number of cells showing myofibrillar degeneration. It is postulated that this is a pluricausal cardiomyopathy similar to several experimental conditions. Significance to aerospace medicine is briefly discussed.


Changes in clinical cardiologic measurements associated with high +Gz stress. Because of reports of subendocardial hemorrhage and myofibrillar degeneration in animals exposed to sustained high G loads (greater than +6 Gz for 15 s or more), questions have been raised regarding the safety of exposing pilots and human subjects to the similar G-stress levels likely to be encountered in the new high-performance fighter aircraft. Noninvasive clinical cardiologic data, including ECGs, vectorcardiograms, systolic time intervals, and maximal treadmill stress tests, were obtained from two groups of subjects before and at several times after exposure to high-G stress. The group exposed to the greater G stress (three 40-s runs at 8 G and two 40-s runs at 10 G, all in one day) developed moderate cutaneous petechiasis and had other minor physical findings after the G stress, but showed few significant changes in cardiologic data: serum total CPK and LDH levels rose, and preejection period shortened at 48 h poststress. The group exposed to the lesser G stress (one 100-s variable-G maneuver peaking twice at 8 G for 3 s, once a week for 3 weeks) had no symptoms following the G stress, but the vectorcardiograms revealed transient T-loop angle changes, and preejection period measured at 1 week poststress was significantly decreased. Because the serum enzyme changes were noncardiac in origin, and because the few other changes were not in a direction indicative of cardiac damage, we conclude that the G stresses imposed in these studies were not significantly injurious.


Space flight effects on skeletal bones of rats (light and electron microscopic examination). In the light and electron microscopes, long tubular bones of Wistar rats that were flown for 22 d onboard the Cosmos-605 biosatellite and were exposed to a ground-based simulation experiment were examined. About half of the flight rats showed osteoporosis of metaphyses which was usually combined with a decrease of the mass of the primary spongiosa in the vicinity of the epiphyseal cartilaginous plate. This gives evidence that the growth of the bones could have been inhibited in flight. The light and electron microscopy of bones of flight rats revealed wide osteocyte lacunae which could have been produced by perilacunar osteolysis. In the simulation experiment, reduction in the metaphyseal spongiosa occurred only in one-third of the rats and was less pronounced than in flight rats; no decrease of the mass of the primary spongiosa near the cartilaginous plate was noted. Histological investigation of bones 27 d postflight demonstrated that that time period was not enough to eliminate all the changes in the bones tested.


Effect of pre-adapting spectral stimuli on visual responses. Electroretinograms (ERGs) were recorded following pre-adapting exposures to radiometrically and photometrically matched spectral stimuli. The magnitudes of three aspects of the ERG varied as a function of the pre-adapting wavelength. Longer wavelenght pre-adapting stimuli produced less suppression of the response magnitudes than stimuli from the short wavelenght end of the spectrum. The implications of the findings for display design and cockpit-light-source design and management are discussed.


Cardiovascular function during sustained +Gz stress. The development of aerospace systems capable of very high levels of positive (+Gz) stress, has created a need for a better understanding of the cardiovascular responses to acceleration. Using a canine model, the heart and cardiovascular system were instrumented to continuously measure coronary blood flow, cardiac output, left ventricular and aortic root pressure, and oxygen saturation in the aorta, coronary sinus, and right ventricle. The animals were exposed to acceleration profiles up to +6 Gz, 120 s at peak G; a seatback angle of 45 degrees was simulated in some experiments. Radiopaque contrast medium was injected to visualize the left ventricular chamber, coronary vasculature, aorta, and branches of the aorta. The results suggest mechanisms responsible for arrhythmias which may occur, and subendocardial hemorrhage which has been reported in other animals.


Application of hyperbaric oxygen therapy in a case of prolonged cerebral hypoxia following rapid decompression. The first known and previously unpublished report of the use of hyperbaric oxygen (HBO) in the treatment of prolonged cerebral hypoxia is reported in an incident involving a USAF T-39 aircraft that underwent rapid decompression from 753 mb (2,438 m or 8,000 ft) to 148 mb (13,716 m or 45,000 ft). Within 5 to 8 s, the pilot lost consciousness because he did not don his oxygen mask and, therefore, was unable to obtain supplemental oxygen immediately. After a delay of 6 to 8 min, he was given supplemental oxygen at and below 697 mb (3,048 m or 10,000 ft). On the ground, the pilot was blind and disoriented. This condition persisted for 6.5 h, at which time HBO was administered. Orientation and vision were regained; neurologic findings were negative. It is concluded that HBO therapy was effective in treating this case of prolonged cerebral hypoxia. The report shows 1) the potential application of HBO in the treatment of prolonged cerebral hypoxia, and 2) the need for developing safe procedures for descent of passenger aircraft following such decompressions.


Effects of time zone changes on performance and physiology of airline personnel. This study is the second of a series of experiments describing the effects of time zone changes on the performance and menstrual cycle changes in a group of 16 female airline personnel. Four groups of four subjects each spent 4 d in the isolation unit of the University of Manchester. One group acted as control; the other three groups were subjected to two 8-h retardations in time, representing Westerly flight. All groups were required to complete an identical battery of workload tasks. In addition, the effects of a therapeutic preparation (mepiprazole hydochloride) were studied in a double-blind experiment. The results of the study confirmed previous experiments in that there was impaired performance in individuals subjected to time zone changes when work was carried out in local time, but the results were difficult to compare with those obtained in Easterly shifts. The therapeutic agent appeared to have little influence on the effect of time zone changes upon subjects, although they reported favourably on its use.


Psychotherapy and return to flying duties. The medical records of a group of 112 successive cases refered for psychiatric consultation to the USAF School of Aerospace Medicine were reviewed. Fifty-eight (52%) of these were psychiatrically disqualified but felt to be amenable to psychotherapy, which was recommended. Followup contact was possible in 49 of these cases to show that 38 did, in fact, receive treatment. Of this later group, 18 were successfully returned to flying duties along with six more, who had no formal treatment beyond several consultative visits, for a total salvage rate of 49%. Psychotherapy had previously been proven to be effective under conditions of major wartime mobilization. Its use in peacetime and during limited warfare has been studied only sparsely, except in the German Air Force, and only for specific conditions in the Royal Air Force. Results of this study support the contention that psychotherapy is feasibly effective in allowing other wise disqualified fliers to return to flying duties.


Professional territoriality: a study of the expanded role of the nurse. This study examines the expanded role of the nurse as a specific example of the extension of professional boundaries. Three characteristics of professional territoriality--autonomy, accountability, and identity--were selected as variables in the study. The specific objectives were to examine attitudes of members of the nursing and medical profession toward the expanded role of the nurse, and to test the usefulness of the concept of professional territoriality in understanding the expanded role of the nurse. Attitudes toward nurses functioning in an expanded role were examined for two aspects: beliefs as to what nurse practitioners are now doing and what they should be able to do. Data was obtained through questionnaries mailed to a random sample of nurses and physicians in Minnesota. As predicted, the researcher found that nurses held more positive attitudes toward nurse practitioners working in an expanded role than do physicians.


Resonance ultrasonic measurements of microscopic gas bubbles. The positive identification and location of stationary or moving bubbles in human tissue is a persisting problem in the study and management of dysbarism. Since bubbles are resonant scatterers of ultrasound, while structures such as red-cell clumps and tissue interfaces are not, it is possible in principle to identify bubbles uniquely and to determine their position and size. A pulsed, ultrasonic echo-ranging system was expressly designed to exploit the principle of bubble resonance, and was evaluated for bubble identification and location in two experiments. Echos from bubbles in a water bath were computer-processed to reveal a distinct "line-narrowing" in the Fourier domain, which is diagnostic of gas bubbles. An increase in echo signal from a dog's jugular vein upon distal bubble injecton was obtained as evidence for in vivo bubble detection. We conclude that the exploitation of the bubble resonance principle can offer a safe, noninvasive technology for micro-bubble identification, location, and size determination in many tissues. This technology appears capable of measuring stationary bubbles in tissue spaces or impacted in blood vessels as well as those moving in the vascular system.


Visual elements in flight simulation.

Visual elements in flight simulation. Flight simulators have been in use for many years and their value has been amply proven. Many of today's simulators are very expensive, but they can pay for themselves by decreasing cost and increasing safety in training pilots to fly complex and expensive modern aircraft. Some aspects of aircraft control depend on an exterior view from the aircraft to the outside visual world. Training in these aspects of flight in a simulator requires simulation of the visual world to the extent that cues derived from it need to be employed by the pilot. A number of maneuvers cannot be performed without direct visual contact under normal circumstances in commercial as well as in military aviation. The importance of including a simulation of the external world is not acknowledged. Unfortunately, there is currently no solid scientific basis for cataloging visual cues with respect to their importance in aircraft control. This report recommends research topics, techniques, and strategies that should receive more attention.


Stress in air traffic controllers: effects of ARTS-III. Physiological, biochemical, and psychological assessments of stress in air traffic controllers were made at Los Angeles (LAX) and Oakland (OAK) Terminal Radar Approach Control (TRACON) facilities before and after installation of Automated Radar Terminal Systems-III (ARTS-III). Heart rates of controllers on duty or at rest scarcely changed from before to after ARTS-III installation. Total stress increased at both TRACONs, and the increase was entirely due to elevated catecholamine excretion. Steroid excretion was significantly reduced at both facilities after ARTS-III had no appreciable effect on work-related anxiety levels of controllers. The post-ARTS-III A-State means for both facilities were not significantly elevated. A-Trait was unchanged at LAX but decreased significantly at OAK. Assessments of A-State showed significant work-related increments but tended to be low. There were no correlations between anxiety and physiological data.


Nystagmus, turning sensations, and illusory movement in motion sickness susceptibility. The relationships of motion sickness susceptibility to nystagmic eye movements, sensations of turning, and duration of the spiral aftereffect were determined with 48 subjects separated into groups on the basis of sex and extremes of motion sickness susceptibility. When subjective alertness levels were controlled, there was no enhancement of elicited nystagmus nor turning sensations in susceptible individuals. However, spiral aftereffect durations were significantly longer in susceptible individuals than in nonsusceptible individuals. The results are interpreted as favoring Graybiel's model of the structural elements in motion sickness.


Effect of sequential anti-G suit inflation on pulmonary capillary blood flow in man. The hemodynamic effects of an anti-G suit, sequentially filled from below upward (M-aG), were compared to those of the standard USAF anti-G suit (S-aG) in 10 men supine and under +1 Gz stress produced by 90 degrees head up passive tilt. S-aG was found to fill from the abdominal bladder downward. The heart rate and the pulmonary capillary blood flow (Qc), as estimated by a nitrous oxide plethysmographic method, were used as criteria of effectiveness. Heart rate did not vary between the suits during the supine and upright studies. In the supine position, the first M-aG inflation induced a significant increase of Qc, 2.5 1 min above the Qc of the S-aG inflation. After 90 degrees head up tilt, M-aG inflation as associated with a significant increase of Qc, 1.7 1 min greater than the Qc produced by S-aG inflation. Since leg bladder inflation may play a critical role in high-G tolerance, the sequential filling from below upward of the anti-G suit may further increase the G protection compared to the standard garment. In addition, the modified anti-G suit may be a useful device for treatment of circulatory shock and postural hypotension when the venous return is decreased.


Protection of airline flight attendants from hypoxia following rapid decompression. To determine the maximum time for working flight attendants to effectively initiate airline passenger mask donning after onset of a rapid, severe decompression, we exposed 10 subjects in two series of tests to a decompression from 6,500 to 34,000 ft (2,000 to 10,400 m) in 26 s, followed by descent at 5,000 ft/min (1,500 m/min) while subjects performed a light-to-moderate workload. Supplemental oxygen was provided in one series from a compressed oxygen system, and in the other series from a chemical oxygen generator system. With delays to mask doning of 10 and 15 s, no hypoxic effects occurred. With delays of 20 and 25 s, increasing hypoxic effects, similar in frequency for the two systems, occurred. Some technical problems in mask donning contributed to losses of consciousness with the latter two delays.


Changes in blood enzyme activity and hematology of rats with decompression sickness. Plasma activities of lactic dehydrogenase (LDH), creatine phosphokinase (CPK), glutamic pyruvic transaminase (GPT), and alkaline phosphatase (ALP) were studied, along with hematological changes, in rats suffering from various degrees of experimental decompression sickness (DS). By 1 h after decompression, LDH and CPK activities were elevated in moderate and severe DS whereas GOT and GPT were elevated only in severe DS. ALP was reduced in all decompressed rats. Hematological changes indicated hemoconcentration, the degree of which paralleled the severity of DS. By 24 h after decompression, all enzyme activities were approaching control levels with the exception of GOT, which was further elevated from the 1-h value. The observed lung damage in rats with severe DS in conjunction with the hematologic and enzyme data suggested that hypoxemic-hypoxia, incident to bubble embolization of pulmonary vasculature, was a major factor in altering the blood enzyme pattern in DS. Serum enzyme data from two inadequately decompressed divers are also reported.


Identification of an apprehension effect on physiological indices of thermal strain. A laboratory assessment of the thermal strain produced by wearing a protective clothing assembly, in addition to a normal flying clothing assembly, in a hot environment is described. In addition to the demonstration of an increase in thermal strain when wearing the protective clothing, two points of importance emerged. First, condition replication revealed a significant apprehension effect which confounded the physiological variables used to evaluate the thermal strain, leading to an over-estimation of the severity of that strain. Second, there was a large between-subject variation amongst the eight subjects used, which made the arithmetic mean a potentially misleading statistic for evaluating the increased physiological strain caused by the additional clothing assembly during the heat exposure. The practical implications of these observations are discussed....


Selective toxicity of 1 atmosphere of oxygen during morphogenesis of two Lepidopterans. Continuous and interval exposures to 1 atmosphere of oxygen (hyperoxia) were examined using insects. Hyperoxia did not affect hatchability of Heliothis zea or Trichoplusia ni. Continuous hyperoxia was 100% lethal for H. zeal and T. ni. Most insects died as larvae and pupae of H. zea which resulted were deformed, reduced in weight, and failed to emerge. Hyperoxic exposures of T. ni for 48 h at sequential 48-h intervals during development, revealed that first instar and prepupae were most sensitive to hyperoxia and 80% were killed when exposed to only 24 h of hyperoxia as prepupae. T. ni which survived hyperoxia exposures at all development stages tested, were capable of producing progeny. The differential hyperoxic sensitivity and its correlation with specific morphogenetic stages suggest the usefulness of these insect species for studying biochemical sites of oxygen toxicity.


Mathematical model of man's tolerance to cold using morphological factors. A mathematical model has been developed to anticipate the physiological responses and the thermal state of a naked human under exposure to cold, taking into account his morphological characteristics (skinfold, size, weight) and the environmental conditions (air or water temperature and velocity, barometric pressure and hygrometry). The skinfold conditions the body's thermal conductance and the metabolism depends both on rectal (Tre) and mean skin (Tsk) temperatures. After being tested, this model was used to study the evolution of Tre. It shows the influence of the skinfold which accounts for most of the inter-individual differences. It also permits discussion of survival possibilities during immersion and completes data provided by previously established curves.


Interaction of hyperbaric nitrogen and oxygen effects on behavior. Breathing elevated environmental pressures of nitrogen and oxygen produced changes in behavior of rats that evidenced an interaction between the two gases. Rates of responding generated by a fixed-interval schedule of reinforcement systematically changed as partial pressures of nitrogen were elevated from 0.8 to 10.4 ATA. Response rates increased above baseline followed by a decline in rates as a function of increasing nitrogen pressure. Concurrent increases in partial pressures of oxygen from 0.2 to 2.2 ATA potentiated the rate-increasing effects of nitrogen at low to moderate nitrogen pressures and enhanced rate-decreasing effects at higher nitrogen pressures. Raised oxygen pressures modulated and interacted with the narcotic effects of nitrogen on behavior.


Physiological effects of solar heat load in a fighter cockpit. The use of bubble canopies to improve vision in fighter aircraft exposes the cockpit to a high radiant heat load. Incoming sunlight increases the heat stress on crewmembers, both by raising air temperature and by directly heating exposed skin and clothing. An F-15 aircraft at Edwards AFB was modified to permit cockpit ventilation by external ground carts. Eight volunteers from the Test Pilot School were studied during 1-h periods in the closed cockpit, in sun and in shade. Mean cockpit air temperatures were 35.2 degrees C in shade and 51.9 degrees C in sun with PH2O less than 10 torr. The corresponding WBGT's were 22.6 and 36.4 degrees C. Sunlight added significantly to overall heat stress, as indicated by a rising heart rate and evaporative weight loss of 284 g/m2 - h (shade value was 109 g/m2 - hr). Mean skin temperatures were 34.3 degrees C in shade and 35.8 degrees C in sun. Particularly high skin temperatures were observed on the chest, the forehead and the top of the head under the helmet. The legs remained cool due to the flow of conditioned air, and this may explain why rectal temperature showed no meaningful change. Heat stress, which alone poses no physiological hazard, may cause crew performance decrements as well as diminishing acceleration tolerance. Possible means of eliminating or ameliorating these effects are discussed.


Intravascular bubbles associated with intravenous injections and altitude. Ultrasonically detected microbubbles were more abundant in the pulmonary artery of dogs intravenously injected with 10 ml of saline than in the same noninjected controls during 10,000 ft (3,048 m), 20,000 ft (6,096 m), and 40,000 ft (12,192 m) exposures. Continuous intravenous (i.v.) drip infusions also introduced many small bubbles. Since they may serve as "nuclei" for visible intravascular bubble formation, are sometimes associated with decompression sickness, and are additionally considered undesirable, it would appear prudent to minimize i.v. injections immediately before flights. However, a 10-min delay before ascent will reduce their number and a 60-min delay will insure their almost complete absence. Also, slow ascent, a 1-h denitrogenation time, or use of a degassed solution will help reduce their total number.


Psychomotor test performance and sleep patterns of aircrew flying transmeridional routes. Pilots and flight attendants flying scheduled services between Vancouver and Tokyo and between Toronto and Rome were tested on a tracking task before and after flights in each direction. Flights were included in schedules involving both 24-h and 7-d layovers at the overseas station. During these periods, they recorded their sleep patterns. The data showed that, following flight, subjects made an immediate attempt to adapt their behaviour to local time and the changes in their performance scores could be interpreted on that basis. It was concluded that behavioural circadian rhythms adapt rapidly to a new time zone.


Long-duration exposure to intermittent noises. The effects were examined of various patterns of interruption--of continuous noise by periods of quiet--on the growth and recovery of temporary threshold shift of hearing over an exposure period of 24 h. Monaural thresholds of hearing were measured prior to, during, and following exposure to a pink noise at a level of 85 dBA and to four conditions in which the pink noise was interrupted with various on-off ratios. The interrupted exposure patterns and levels were adjusted to make their average levels equivalent to 85 dBA. Among the results: 1) the growth of TTS clear.ly reached an asymptote for all interrupted exposure conditions, even when the TTS was as small as 5 dB, 2) the interrupted exposures produced lower asymptotic levels than the continuous exposure with the same amount of energy, and 3) the TTS recovery patterns were essentially the same at 1 h and beyond, for all conditions. These data support the concept that, following a long exposure, one should be provided at least as much time for recovery as the duration of the exposure.


Perception of everyday visual environments during saccadic eye movements. Subjects were required to execute saccadic eye movements in the horizontal plane which passed through primary gaze. During the saccades, visual images were projected onto a screen which subtended 40 degrees horizontaloy and 26 degrees vertically and was centered on primary gaze. Content, contrast, and intensity of the stimulus patterns and level of illumination of the laboratory background were manipulated to maximise pattern recognition. Little or no detail of the projected images could be discerned under any conditions. Only horizontal laminations were perceived as blurs of appropriate colour. It is concluded that there is no useful perception of the everyday environment during saccades.


Screening test for decompression sickness. The fibrin-fibrinogen degradation products (FDP) tests were studied in 18 patients having a history of illness associated with diving. FDP tests were performed prior to hyperbaric oxygen therapy (OHP). Eight patients were serious neurologic signs had positive FDP tests and required repetitive therapy. Six patients had negative FDP tests with local musculoskeletal complaints and all were asymptomatic following the first OHP treatment. Three patients were found to be suffering from other diseases. These three patients had normal levels of FDP. One patient treated at another facility 3 months earlier and having paraplegia had a positive FDP test. Serious decompression sickness with neurologic complaints appear to have some degree of disseminated intravascular coagulation (DIC) as reflected by the FDP tests. The FDP test appears to be a useful screening test that may be able to delineate therapy.


Incidence of decompression sickness in Navy low-pressure chambers. This study reports the incidence of decompression sickness occurring in U. S. Navy altitude chambers in association with physiological training of aircrews for the period 1 Jan. 1972 to 31 Dec. 1975. There were 79 cases of decompression sickness in 88,520 altitude chamber exposures, an incidence of 0.089%. Among trainees, there were 22 cases in 73,561 exposures, an incidence of 0.029%. Among chamber inside observers, there were 57 cases in 14,959 exposures, an incidence of 0.38%. This 12-fold greater incidence among inside observers over trainees was statistically significant (p less than 0.01). Reasons for the increased incidence of decompression sickness among inside observers are discussed.


Characteristics of ultrasonic scattered signals from emboli in blood. Received ultrasonic scattered signal expressions are presented for the case of an individual scatterer moving through a Gaussian beam pattern. The return signal is of a burst-like nature and oscillates as a function of time under a Gaussian amplitude envelope. Results are presented to show specific parameter dependence on the scatterer motion and beam configuration to aid in the use of the technique of ultrasonic scattering for detecting and monitoring the motion of emboli formed in blood during decompression or open-heart surgery.


Antiarrhythmic effect of solvents: propylene glycol, benzyl alcohol. Propylene glycol and benzyl alcohol, the main constituents of most solvent vehicles, display a pronounced antiarrhythmic-antifibrillatory effects, when injected intravenously into animals (dogs, rats) with spontaneous or drug-induced arrhythmias. The antiarrhythmic dose for propylene glycol amounts to 0.2-0.3 ml/kg of a 70 per cent solution and, for benzyl alcohol to 0.2-0.4 ml/kg of a 4 per cent solution in physiologic saline, respectively. Similar effects were also obtained by the combined injection of propylene glycol + benzyl alcohol, in proportions which correspond to the formulae of numerous commercial "solvents" (vehicles): 2 to 20 per cent solutions of benzyl alcohol in 70 per cent propylene glycol (0.05-0.2 ml/kg). The mechanisms which might be responsible for the antiarrhythmic activity of solvents are discussed: lengthening of the effective refractory period, local and general anaesthetic effects, changes of osmolarity. The intravenous injection of propylene glycol and/or benzyl alcohol, in high doses, produces intravascular haemolysis. Clinical investigations are recommended as to the potential, beneficial or toxic effects of drug solvents, especially upon the cardiocirculatory system.


[Recording of ventricular pressure by conventional catheter manometer systems. Efficiency of several combinations of conventional catheters, modern transducers and catheter-flush systems (author's transl)]. The experimentally in vitro determined dynamic response characteristics of 38 catheter manometer systems were uniform in the worst case to 5 c.p.s. and optimally to 26 c.p.s. Accordingly, some systems are only satisfactory for ordinary pressure recording in cardiac rest, while better systems record dp/dt correct up to moderate inotropic stimulation of the heart. In the frequency range of uniform response (amplitude error less +/- 5%) the phase distortion is also negligible. In clinical application the investigator is often restricted to special type of cardiac catheter. In this case a low compliant transducer yields superior results. In all examined systems the combination with MSD 10 transducers is best, whereas the combination with P 23 Db transducers leads to minimal results. An inadequate system for recording ventricular pressure pulses leads in most cases to overestimations of dp/dtmax. The use of low frequency pass filters to attenuate higher frequency artefacts is, under clinical conditions, not suitable for extending the range of uniform frequency response. The dynamic response of 14 catheter manometer systems with two types of continuous self flush units was determined. The use of the P 37 flush unit in combination with small internal diameter catheters leads to serious error in ordinary pressure recording, due to amplitude distortion of the lower harmonics. The frequency response characteristics of the combination of an Intraflow flush system and MSD 10 transducer was similar to the non-flushing P 23 Db transducer feature.


Noncompetitive catecholamine-antagonism of acetylcholine in the sympathectomized mammalian ventricular myocardium. The effect of the vagus transmitter on the ventricular myocardium varies qualitatively as well as quantitatively in different warm-blood species. In the ventricular myocardium of birds (duck, hen), a part of the acetylcholine sensitivity remains even after catecholamine depletion. In contrast, the inhibitory effects of acetylcholine on the ventricular myocardium of mammals (rat, guinea pig, cat, dog, man) depend on the activity of the sympathicus. In the chemically sympathectomized (6-OH-DA) cat ventricular myocardium, a cholinergic innervation is, histochemically, clearly demonstrable. Correspondingly significant effects of endogenous (i.e. releasable by field stimulation) and exogenous acetylcholine can be seen if the contraction force is enhanced by exogenous catecholamines. This preparation is, therefore, a good model for the demonstration of a catecholamine antagonism of acetylcholine. Using this model, on the basis of dose-response relationships, it is possible to demonstrate that a noncompetitive catecholamine-antagonism of acetylcholine indeed exists in the mammalian ventricular myocardium independent of a cholinergically mediated reduction in the norepinephrine release.


[Aberrant subclavian arteries: predominance in females (author's transl)]. Thirty-five cases of aberrant subclavian artery were observed in 1408 consecutive necropsies on fetuses, newborns, infants and children; the autopsies were performed by the same pathologist. The right subclavian artery was found to be involved in 32 cases, the left subclavian artery in 3 cases. The artery always passed behind the esophagus. In 12 of the cases, the aberrant subclavian artery occurred as an isolated anomaly. In the remainder of the cases the aberrant subclavian artery was associated with malformations of the heart and the great vessels; coexistent extracardial defects were also noted. Of the 35 cases 13 were males and 22 females. In reviewing the literature a series of 431 cases is presented. Of these cases the aberrant subclavian artery occurred in 177 males and 254 females. The predominance in females is statistically established.


"Non-condensed" and "condensed" chromain in transitional cell carcinoma of the human urinary bladder. The area and content of "non-condensed" and "condensed" chromatin in smeared Feulgen-stained malignant urothelial cells were determined by means of scanning-cytophotometry. The results were compared with those from similar measurements of benign human transitional epithelial cells. There was no difference between the relative area and content of "non-condensed" and "condensed" chromatin in cancer nuclei and normal urothelial nuclei as far as nuclei of the same size and ploidy class were considered. Within the same ploidy class the relative area and content of "non-condensed" chromatin increased with increasing nuclear size. As increased nuclear size within the same ploidy class is typical for most cancer cells, cancer specimens therefore contained relatively more "non-condensed" chromatin than normal urothelium. Analogously the relative values of "condensed" chromatin decreased in cancer specimens. Only in high-polyploid cancer cells, which occurred more frequently in undifferentiated tumours, a slight decrease of the relative area and content of "non-condensed" chromatin was observed as compared with well differentiated diploid tumour cells. It was in polyploid tumours that the absolute area and content of "condensed" chromatin was increased as compared with diploid normal urothelium. This means that the changes in "non-condensed" and "condensed" chromatin were primarily dependent on nuclear size and total chromatin content and were not found to be a characteristic of cancer nuclei as compared with control nuclei of the same size and ploidy. These findings differ from the results of biochemical analyses of heterochromatin both in cells during carcinogenesis and also in cancer cells, but are in agreement with qualitative and quantitative morphological studies of smeared cancer nuclei.


[Sarcoma 180: growth and regression. Comparative investigations using flow-through and scanning cytophotometers as well as histological, cytological and autoradiographic techniques (author's transl)]. The growth and the regression of the experimental tumor S 180 was investiaged by volume measurements and by cytophotometric studies on 50 mice in each of a pilot and in the present main experiment. In addition, histological, cytological and cytokinetic examinations were performed. Beginning on day 18, a spontaneous regression of the tumor was found in 20% and 38% of the animals, respectively. DNA-measurements were performed with a scanning-microspectrophotometer on tumor tissue imprints and tumor cell suspensions and were also carried out with a flow-through cytophotometer ICP on suspensions. DNA-histograms were plotted on days 4, 7, 12, 18, 20, 22, 26 and 29 after the transplantation. These revealed a constant position of the maxima at 2C for normal cells and at 4C and 8C for the tumor cells. In particular, by measuring a large total number of 4,968,000 nuclei with the ICP, distinct changes were found in the proportion of the single nuclei classes during growth and spontaneous regression. This technique also enables a quantitative measurement to be made of the DNA of cell debris from necrosis. With growing tumos, the proportion of the tumor cells increased to a maximum of 65% on day 18 and decreased to 37% on day 29. The DNA of cell debris grew from 8% to 47%. The proportion of normal cells was only 10% to 15% in the final phases. In tumors with a spontaneous regression the proportion of the tumor cell nuclei was 20% on day 18 and 11% on day 29. The proportion of the DNA of cell debris was again about 45%. The proportion of normal nuclei was greatly increased to 45%. Histological and cytological evidence together with measurements of the areas of nuclei and incorporation of 3H-TdR confirmed that the normal cells, the number of which increased during spontaneous regression were cells of a fibrovascular granulation tissue. While the rate of the DNA-synthesis of growing tumors continously decreased with age there was also a rapid decrease of the labelling index of spontaneously regressing tumors between days 12 and 18. In the final phase only the nuclei of the granulation tissue were labelled.


The dynamics of collagen deposition in liver damaged by CCl4. The rates of synthesis and catabolism of collagen are determined in the livers of normal rats and of rats treated with carbon tetrachloride. Several experimental conditions are applied with the intention of investigating the dynamic processes separately, in order to determine the relevant values. The deposition of collagen in liver after damage by CCl4 is a consequence of the reduction of turnover with a simultaneous increase in collagen-production. Together with the increase in synthesis, which seems to be a consequence of a numerical increase in cells, there is a reduction in catabolism of collagen: the more severe the damage, the more marked is the decrease of specific catabolism. Collagen-deposition in the liver is thus the result of accumulation. The results indicate the possibility that collagen-catabolism is effected by enzymes produced by adjacent parenchymal cells, so that their destruction enhances the accumulation of collagen material. The findings mentioned above are discussed in the context of the general criteria of scar-formation and the repair of damaged tissues.


[Benign solid teratoma of the uterus (author's transl)]. On curettage, done in a 39 year old patient because of metorrhagia, a peanut-sized nodule was scraped away from the endometrium. Histologically it consisted of a jumble of irregularly shaped portions of normal appearing embryonal cartilage, of tortuous thick-walled vessels, of twisted bundles of nerves of ducts of respiratory and intestinal epithelium, and of sheets of hornifying skin. The haphazard disarray of tissues supported the notion that the lesion was not a remnant of a malformed embryo. Step-sections through the lesion revealed no traces of placental villi or decidua in the surrounding endometrium. The following were considered as possible origins of the teratoma: 1. displaced germinal cells, 2. retention of pluripotent müllerian epithelium, 3. overaged or blighted ovum. The latter seems most compatible with the histological findings.


Polymorphism and predictability at the alpha-glycerophosphate dehydrogenase locus in Colias butterflies: gradients in allele frequency within single populations. Heterozygosity at the alpha-glycerophosphate dehydrogenase locus of five species of Colias butterflies is widespread in montane populations; alpine and lowland populations are not heterozygous. Within a single demographically characterized population of C. meadii where the population extends from alpine down into montane habitats, a marked cline in allele frequency is seen. Such within-population clines suggest the involvement of strong selection across the marked ecological interface. Thermal factors are the most likely causative agents, but associative overdominance is not excluded.


Genetic control of LDH isozymes in the house fly, Musca domestica. Electrophoretic variations in lactate dehydrogenase from adult whole body homogenates are described for three laboratory strains of house flies, Musca domestica. Several crosses between different electrophoretic forms provided evidence that the observed variations are due to segregation of alleles at two distinct loci (designated as A and B loci) and that the LDH isozymes of house flies are dimers formed by a random association of subunits controlled by the two loci.


Patterns of molecular variation. I. Interspecific comparisons of electromorphs in the Drosophila mulleri complex. The average mobility of electromorphs at an enzyme locus in a single population was defined as the weighted average mobility of the electromorphs in that population, where the electromorph frequencies are the weights. A derivative distance measure was defined whose taxonomic utility was determined in the Drosophila mulleri species complex. Most of the variation in this metric was at the interspecific level, primarily among clusters of sibling species. The electromorphs of some loci were equally and regularly spaced, while those of other loci were less regular in their spacing. Overall, these minor perturbations from regular spacing did not noticeably detract from the taxonomic utility of average mobility, and cluster analysis yielded the same taxonomic relationships as more conventional nonmolecular treatments. On the other hand, electromorph spacing may be related to functional constraints on the enzyme molecules. Some possible implications of the results for the modes of selection during evolution of the different enzymes are discussed.


Esterases in the mosquito Culex pipiens pipiens L: formal genetics and polymorphism of adult esterases. The genetics of two esterase loci active in autogenous adults of the mosquito Culex pipiens pipiens L. has been studied by means of starch gel electrophoresis. Three alleles at the Est-1 locus and eight at the Est-2 locus are described. Both loci have a null allele. Active alleles are codominant and there is no hybrid enzyme in heterozygotes. The Est-1 locus codes esterases preferentially hydrolyzing alpha-naphthylacetate and the Est-2 locus esterases preferentially hydrolyzing beta-naphthylacetate. Strains homozygous for both loci were selected. Linkage studies of the two loci have shown that they are not sex linked but are linked to each other, the crossover frequency being 8.6%. The polymorphism of two laboratory and two natural populations is described for both loci. Phenotypic distributions are in good agreement with Hardy-Weinberg expectations.


Autosomal genetic control of the activity of a new variant ornithine transcarbamylase in chicken kidney. The mode of inheritance of the gene for chick kidney ornithine transcarbamylase (OTC), found previously as a genetic variant, was investigated. White Leghorn B line males homozygous for the allele for the variant OTC gene were selected using the California Gray breed, having a near-absolute deficiency of the enzyme. Then further crosses of the two breeds were made. The mean value of the OTC level of F1 progeny was about 170 units. Chicks from the backcross generation were divided into two groups, of high activity and low activity, in a ratio of 1:1. F2 chicks were divided into three groups: one-fourth of the chicks were classified as a "super high" group, one-half were "high," and the remaining one-fourth were "low"; the mean values for OTC level were 356.7, 196.4, and 15.6 units, respectively. From these results, it was suggested that the variant OTC represents a simple autosomal incompletely dominant trait.


Water flux through porcine aortic tissue due to a hydrostatic pressure gradient. The water flux through preparations of porcine aorta has been investigated. After an initial unsteady period a stable flux of approximately 2 mul/cm2-h was reached and this flux rate remained constant for several hours. Under the experimental conditions which were maintained (110 mm Hg pressure drop across a 2 mm thick section of tissue) this total flux corresponds to a hydraulic conductivity of less than or equal to 7.0 X 10(-13) cm4/dyne-sec. Since these data were obtained in tissue samples where the endothelial layer was not intact, they represent values which are in fact larger than the actual in vivo condition where the endothelial barrier would serve as an additional resistance. Thus, they demonstrate that the transmural flux of water across the aorta wall in vitro due to a pressure gradient is extremely small and, therefore, that other mass transfer mechanisms may be significant.


Treatment of type II hyperlipoproteinemia with d-thyroxine. The effectiveness of a new, almost l-thyroxine free preparation of d-thyroxine (Dynothel) was tested in 15 patients with Type IIa and 4 patients with Type IIb hyperlipoproteinemia. Eleven patients with Type IIa and 3 with Type IIb were responsive to treatment and showed an average 26% decrease in plasma TC. This decrement in plasma TC was mirrored in a significant reduction of LDL cholesterol in Type IIa and IIb. While VLDL cholesterol slightly decrease in Type IIb, it remained the same in Type IIa and so did the HDL cholesterol in both types. As neither VLDL nor LDL or HDL triglyceride levels changed very much in either type, the total plasma triglycerides remained the same. The plasma phospholipids were higher in Type IIa and lower in Type IIb on therapy. Thus, Dynothel seems to be a potent d-thyroxine preparation for lowering plasma cholesterol, this decrease being brought about by reduction of LDL cholesterol levels. The effect of the drug on plasma TG and PL is less certain.


Number, location and severity of coronary arterial changes in steelhead trout (Salmo gairdnerii). Steelhead trout (Salmo gairdnerii) were taken at three stages of sexual maturity to study their coronary arteries for arteriosclerotic lesions. At least 18 sections from the glutaraldehyde- and osmium-fixed arteries were obtained from each fish. Fish in the middle of the spawning migration and sexually mature fish at the spawning ground had lesions in about 20% of the arterial sections. These consisted of focal proliferations of smooth muscle cells projecting into the lumen through the broken elastic lamina with an intact endothelium around them. Sexually mature fish with patches of fungus on their head and back had twice as high a percentage of arterial sections with lesions as the first two groups of fish. Sexually immature fish were not studied. The lesions occurred approximately equally in all sizes of coronary arteries except for very small arteries. All lesions but one were focal; that lesion involved a third of the intima and the media. The lesions have no elastic lamina below the endothelium and seem to have no lipid.


Hepatic cholesterol-7alpha-hydroxylase activity in neurogenic hypercholesterolemia. The cholesterol-7alpha-hydroxylase activity of hepatic microsomal preparations of hypothalamic hypercholesterolemic rats and normal rats was assayed in rats fed diets high and low in cholesterol, and in rats killed at the supposed height and at the nadir of the diurnal cycle of enzyme activity. The activity of this enzyme system appeared to be unimpaired in the hypothalamic hypercholesterolemic rat.


Treatment of hypercholesterolemia with Secholex. A long-term clinical trial and comparison with cholestyramine. The efficacy of an anion-exchange gel, Secholex, as a hypocholesterolemic agent was assessed in 46 patients in 4 different studies and the effects were compared with those of cholestyramine. All patients had severe Type II-a or II-b hyperlipoproteinemia. In short-term metabolic studies Secholex (15 g/day) and cholestyramine (16 g/day) decreased serum cholesterol levels and increased total fecal sterol output and serum methyl sterol concentration to a similar extent, but cholestyramine was more effective than Secholex in increasing fecal bile acid excretion. In crossover studies, the two drugs appeared to be equally effective in lowing serum cholesterol levels but the patients mostly preferred Secholex. Twenty patients were treated with Secholex over a two-year period. The average decrease in serum cholesterol levels from the mean pretreatment value of 406 mg/100 ml was 15% during the first year, and 13% during the second year. In 5 patients the serum cholesterol was permanently lowered by more than 20% (good responders), while in 7 patients the average reduction of serum cholesterol level during Secholex administration was less than 10% (non-responders). The serum triglyceride level was slightly decreased by Secholex in Type II-b patients but was unaltered in Type II-a patients. At the end of the treatment period, serum iron and vitamin B12 levels were normal but the serum folic acid concentration was reduced in eight of 20 patients. A dose--response study indicated that a similar cholesterol-lowering effect was obtained with daily doses of 9 and 15 g of Secholex. It is concluded that Secholex is a relatively safe drug which effectively reduces serum cholesterol levels in two-thirds of patients with severe hypercholesterolemia.


Effect of the phospholipid vehicle on the transport of cholesterol in rats. Rats were injected intravenously with liposomes made of [4(-14)C] cholesterol with [32P]lysolecithin, or [4(-14)C]cholesterol with [32P]lecithin. The clearance of both radioactive labels from plasma was observed, as well as their distribution in the organs after 15 and 60 min. At the same time, the esterification of injected [14C]cholesterol and the conversion of [32P]lysolecithin to [32P]lecithin and vice versa were examined. [14C]Cholesterol administered with lysolecithin was cleared from the plasma at a higher rate than with lecithin. Consequently the radioactivity of [14C]cholesterol in the aorta, heart, lung, kidney and liver changed with the applied phospholipid; with lysolecithin it was higher than with lecithin. Lysolecithin itself was distributed among the organs more evenly than lecithin, which accumulated most in the liver. If administered with lysolecithin, [14C]cholesterol was esterified in the plasma in a significantly higher proportion than if administered with lecithin. The antiatherogenous effect of lecithin and the atherogenous effect of lysolecithin are considered on the basis of different transport properties of these phospholipids.


Incorporation in vitro of 14C-labelled acetate and 32P-labelled phosphate into lipid in thoracic aortae from hypertensive and nomotensive rabbits. The effect of prior hypertension on lipid synthesis in the thoracic aortae of normal-fed and cholesterol-fed rabbits was studied in vitro using[1(-14)C] acetate and [32P] phosphate as lipid precursors. In normally fed rabbits, prior hypertension did not increase the incorporation of the labelled precursors into either phospholipid or neutral lipid. In cholesterol-fed rabbits, hypertension increased the incorporation of [32P] phosphate into phosphatidyl-choline and of [1(-14)C-acetate into cholesterol ester. The increased incorporation of [1(-14)C] acetate into cholesterol ester was accompanied by an increase in intimal total cholesterol concentration. For both normotensive and hypertensive cholesterol-fed rabbits there was a close correlation between cholesterol esterification and total cholesterol concentration of the thoracic intima. It is concluded that the increase in aortic lipid synthesis in hypertensive cholesterol-fed rabbits is secondary to the increased cholesterol accumulation induced by hypertension rather than to a direct stimulation of arterial wall lipid synthesis by hypertension per se.


Ischaemic disease in men and women with familial hypercholesterolaemia and xanthomatosis. A comparative study of genetic and environmental factors in 274 heterozygous cases. The incidence of ischaemic diseases in familial hypercholesterolaemia and xanthomatosis (familial Type II) was studied in a group of 158 men and 116 women. (1) Men and women did not differ with regard to the inherited metabolic disease. Levels of serum cholesterol, the marker of the genetic defect, were not statistically different, and cholesterol deposition in tissues, visualized by skin tendon xanthomas, was not sex related. (2) Men and women were different with regard to ischaemic diseases. The incidence was much lower in women, and the mean age of onset 9 years later. Moreover, there was a sex difference in the nature of the ischaemic disease, with a high male predominance of myocardial infarction. (3) Since the major risk factor hypercholesterolaemia could not explain such a difference, the role of other risk factors was investigated. It was shown that the incidence of ischaemic diseases was increased in women by cigarette smoking and hypertension, and that the difference in age of onset between males and females was no longer seen in smoking women. It is suggested that the genetic factor is responsible for the atherosclerotic lesion in both sexes and that other factors playing a role in ischaemic complications including tobacco and hypertension may explain the difference between men and women.


Comparative histological and morphometrical studies into the relevance of intimal thickening to coronary sclerosis. It was found by comparative histological and morphometrical studies, carried out on 125 human hearts of different age (20-90 years) and sex, that there exist critical limiting ranges of intima thickness and the intima/media relationship (IMR) for diffuse intimal thickening and the preatheroma phase of arteriosclerosis. Since furthermore a maximum and a minimum intima thickness as relating to diffuse intimal thickening could be determined, it is assumed that the location and formation of arteriosclerotic plaques is determined by the degree of so-called diffuse intimal thickening. It follows from these findings that postnatal intimal proliferation represents a potential prearteriosclerotic lesion of the intima, and that progressive intimal thickening supports the arteriosclerotic alteration of the intima, leading, through an extensive necrosis of the intima, to the atheroma phase.


Estrogen treatment and gonadal function in the regulation of lipoprotein lipase. Lipoprotein lipase (LPL) activity was measured in adipose tissue, heart and diaphragm in Sprague--Dawley rats after estrogen therapy or orchiectomy. Enzyme activity was measured by incubation of tissue fragments with a triolein emulsion in the presence of serum and heparin. In confirmation of other work, depression of adipose tissue LPL followed estradiol treatment in pharmacologic or near-physiologic doses. Cardiac and diaphragmatic muscle LPL were increased. Estrogen-treated male animals showed growth retardation. However, they gained weight steadily and did not show significant differences in serum insulin, glucose of D-beta-hydroxybutyrate. The effects of estradiol in male animals were reversed by sequential fasting and re-feeding. At times during growth and aging in normal female rats, adipose tissue activity was decreased while cardiac and skeletal muscle activities were increased relative to males of the same age or body weight. Castration of male rats failed to reproduce the effect of estrogens on tissue lipoprotein lipase. These in vitro data suggest that exogenous estrogens may shift the flux of triglyceride fatty acids from storage in the adipose organ toward incorporation by muscle. These, and other data, raise the possibility that physiological estrogen secretion exerts a tonic influence over the synthesis and ultimate destination of triglyceride fatty acids.


Chylomicron metabolism in rabbits fed diets with or without added cholesterol. Intestinal lymph chylomicrons, isotopically labelled with radioactive triacylglycerol and cholesterol, were injected into normally fed and cholesterol-fed rabbits in order to establish the pattern of clearance of intestinal lipoproteins from the plasma. In normal rabbits the cholesterol moiety of chylomicrons was removed from the plasma less readily than triacylglycerol. In cholesterol-fed rabbits, the clearance of triacylglycerol was unaltered, but clearance of chylomicron cholesterol was further retarded. The majority of the injected lymph cholesterol was recovered in d less than 1.019 g/ml lipoproteins. These observations support the notions that clearance of chylomicron remnants is impaired in the rabbit, and that hypercholesterolaemia in the cholesterol-fed rabbit is due to an accumulation of chylomicron remnants in the plasma.


Effect of dietary restriction on plasma cholesterol and cholesterol excretion in the White Carneau pigeon. The effect of short-term dietary restriction on plasma cholesterol and cholesterol balance was examined in young While Carneau pigeons. Dietary restriction of 1 month increased plasma cholesterol significantly and subsequently decreased to initial levels at 3 months. The fecal excretion of neutral sterols was significantly reduced (P less than 0.001) at both 1 and 3 months following dietary restriction, while the fecal excretion of bile acids showed no significant changes.


The effect of intermittent carbon monoxide exposure on experimental atherosclerosis in the rabbit. (1) Twenty-four female New Zealand White rabbits were fed commercial diet plus 2% cholesterol. Twelve of these animals were exposed to carbon monoxide for 4 hours per day, seven days per week for 10 weeks. The carbon monoxide exposure was such that the mean blood carboxy-haemoglobin was raised to approximately 20% during each exposure period. Twelve control animals breathed atmospheric air under the same conditions of confinement as the carbon monoxide-exposed group. (2) No significant differences in the plasma levels of cholesterol, triglycerides or glutamate oxalacetate transaminase were observed between the two groups during the experiment. (3) When the animals were sacrificed at the end of the experiment no significant differences were observed between the two groups in the aortic content of triglycerides, cholesterol or phospholipids. (4) The extent of coronary artery atherosclerosis was statistically significantly higher in the carbon monoxide group than in the control group. (5) Ultracentrifugal analysis of plasma lipoproteins revealed that there was significantly more cholesterol in the d less than l.006 fraction from the CO-exposed rabbits. (6) These findings, are discussed with particular reference to the claim that the causal agent in tobacco smoke associated arterial disease is carbon monoxide.


Effects of clofibrate treatment on plasma triglyceride concentration, plasma post-heparin clearing factor lipase (lipoprotein lipase) activity and serum clearing factor lipase activating ability in maturity-onset diabetes. The effects of clofibrate on plasma triglyceride concentration, plasma post-heparin clearing factor lipase activity and serum clearing factor lipase activating ability were studied in a group of maturity-onset diabetic patients. Significant falls in both triglyceride concentration and in activating ability occurred within 2 weeks of beginning clofibrate treatment and, when treatment was stopped after 4 weeks, these changes were reversed within a further 4 weeks. Plasma post-heparin clearing factor lipase activity, on the other hand, was significantly increased during clofibrate administration and fell again when the treatment was stopped. The possible interrelationships of these findings are discussed.


On the cholesteryl ester hydrolase activity in the microsomal and supernatant fractions of pigeon aorta. Cholesteryl ester hydrolase activity was measured in the microsomal and supernatant fractions of the aorta of atherosclerosis-susceptible White Carneau and atherosclerosis-resistant Show Racer pigeons while on their normal cholesterol-free diets. Enzyme activities from both fractions showed fatty acid specificities for the hydrolysis of different cholesteryl esters in the following decreasing order: Linoleate greater than oleate greater than palmitate. At 9 months of age (the period of lipid accumulation) the microsomal enzyme activity in the Show Racer breed was significantly higher (P less than 0.001) than in the White Carneau breed, while the supernatant enzyme was slightly higher (P less than 0.05) in the White Carneaux at this age. In older birds (3 years of age) these differences in enzyme activities disappeared.