Temperature-sensitive DNA repair of ultraviolet damage in human cell lines. Following exposure to ultraviolet irradiation (UV), two of three human fibroblast strains and one of three melanoma cell lines showed lower rates of thymine dimer excision during 24 h at 40 degrees C than at 36 degrees C. All lines had lower rates at 32 degrees C. Autoradiographic studies of three fibroblast strains and four melanoma lines incubated for four hours after irradiation revealed decreased unscheduled DNA synthesis at 42 degrees C compared with 36 degrees C. The rate of semiconservative DNA synthesis was decreased at the upper temperature in both series of experiments. All eight cell lines tested showed decreased repair at 42 degrees C, as judged by slower sedimentation and increased heterogeneity of parental DNA in alkaline sucrose gradients. Experiments using the DNA synthesis inhibitor Actinomycin D suggested that these effects were due to temperature-sensitive repair synthesis. In the two lines studied, preincubation of cells at 42 degrees C apparently increased the extent of UV damage. Although by no means conclusive, these results are consistent with the possibility that temperature-sensitive DNA repair is a contributory factor in some cases of solar carcinogenesis.


Incidence rates of specific histological types of lung cancer in Singapore Chinese dialect groups, and their aetiological significance. Significant differences in the incidence levels of lung cancer have been observed among major Chinese dialect groups or communities (Kokkien, Teochew and Cantonese) in Singapore. Among males, the incidence rate is highest in the Hokkiens (age-standardized incidence rate per 100,000 persons per year in Hokkien 67.8, Teochew 55.3, Cantonese 54.0) and among females, it is highest in the Cantonese (Hokkien 12.4, Teochew 12.8, Cantonese 27.2). The present investigation was undertaken to determine the incidence rates of each of the main histological types of lung cancer in the Chinese population and to determine whether there are any correlations between histological patterns and the dialect group differentials that may be of aetiological significance. During the period 1968-1972, a total of 1,747 cases of lung cancer (1,285 males and 462 females) were reported to the Singapore Cancer Registry. It proved possible to type the neoplasms histologically in 476 males (37.0%) and 154 females (33.3%). Age-standardized rates by histological type were computed on the assumption that those histologically typed were a representative sample of all lung cancers. This study shows that Hokkien males have a significantly higher incidence rate of epidermoid carcinoma than the other dialect groups (Hokkien 36.1, Teochew 21.1, Cantonese 17.3). The Cantonese females have significantly higher incidence rates of both epidermoid carcinoma (Hokkien 3.7, Teochew 2.3, Cantonese 5.9) and adenocarcinoma (Hokkien 4.6, Teochew 3.6, Cantonese 11.9). Various sources of bias in studied of this type were examined; it is concluded that the differences in the histologic-specific incidence rates of lung cancer among the various Chinese dialect groups in Singapore are real and not artefactual. The significance of these findings in relation to possible aetiological factors is discussed.


A cohort study on mortality from cancer and other causes among workers at a metal refinery. A non-concurrent prospective study was made on deaths from cancer and other causes occurring among 2,675 male workers at a metal refinery from 1949 to 1971. The expected number of deaths computed by applying age- and cause-specific death rates of Japanese males to these workers was compared with the observed number of deaths. Among 839 copper smelters, significantly increased mortalities were noted for lung cancer (SMR = 1,189) and colon cancer, but nor for cancer of the stomach, liver (primary) and biliary passages, pancreas and skin or for leukemia, tuberculosis, cerebrovascular diseases, heart diseases and liver cirrhosis. A dose-response relationship was demonstrated between the mortality from lung cancer and the degree of exposure. A very high excess mortality from lung cancer (SMR = 2,500) was seen among copper smelters who were considered to have been most heavily exposed to arsenic or workers who had engaged in sintering and blast furnace operations for 15 years of more before 1949. The latent period of lung cancer was 37.6 years on average, and not related to level of exposure. Twenty-six of 29 deaths from lung cancer among copper smelters occurred after they had left the refinery. Other production workers and clerical workers showed no significant excess mortality from any kind of cancer.


Capillary tube leukocyte adherence inhibition: an assay for cell-mediated immunity in cancer patients. The leukocyte adherence inhibition (LAI) assay has been modified and automated in order to facilitate its clinical application. This new assay-the capillary tube LAI test-correlated with delayed cutaneous hypersensitivity using streptokinase-streptodornase antigen in 83% of the cases. When tested with a 3 M KC1 lung carcinoma antigen, lung carcinoma patients' leukocytes were more frequently inhibited (55%) than those of controls (normals 6%, other tumors 20%).


Studies on a gross-virus-induced lymphoma in the rat. III. Optimisation, specificity and applications of the in vitro immune response. Conditions are described for optimal stimulation in vitro of lymphocytes from rats primed in vivo with syngeneic MuLV-G leukaemia cells. Cultures generate effector cells which show high cytotoxic activity against leukaemic cells. Specific stimulation can be obtained with leukaemic cells and with disrupted MuLV. Leukaemic cells, normal spleen cells and the viron internal protein p30 competitively inhibit effector cells, but purified virus exerts non-specific inhibition. These findings are interpreted as supporting the hypothesis that virion antigens constitute a major target of anti-tumour cytotoxic immunity.


The influence of vitamin A on the susceptibility of the rat lung to 3-methylcholanthrene. The susceptibility of rats to pulmonary carcinogens is increased in the absence of vitamin A intake even when considerable amounts (0.4 nmole/mg) of vitamin A are stored in the liver and deficiency symptoms are absent. This was demonstrated in studies on the induction of metaplastic lung nodules by intratracheally administered 3-methylcholanthrene. Only moderate amounts of all-trans-retinyl acetate in the diet (7.6 nmole/g of diet) were required to prevent the development of this state of enhanced susceptibility. A further increase in intake of retinoids (by intragastric administration of either all-trans-retinyl acetate or 13-cis-retinoic acid) provided no additional protection against the effects of carcinogen.


Monkey antisera with increased specificity to carcino-embryonic antigen (CEA). Three Macaca irus monkeys were immunized with purified human CEA. One received unmodified CEA and two were immunized with haptenated (4-hydroxy-5-iodo-3-nitrophenyl acetyl) CEA. All three monkeys formed precipitating antibodies to CEA. The antisera did not precipitate the CEA-related normal glycoprotein antigen (NCA). In contrast, CEA-immunized rabbits, sheep and goats invariably form antibodies against NCA. Radio-immunoassays showed the monkey antisera to contain trace amounts of antibodies to NCA but the titers were about 10-1,000 times lower than those in rabbit and sheep sera with comparable anti-CEA titers. These results show that monkeys produce antibodies against CEA, but respond weakly to a normal, CEA-related antigen. The weak response to NCA suggests that monkeys may possess an NCA-related antigen. Antisera lacking reactivity to normal CEA-related antigens may be helpful in establishing a more specific diagnostic test for CEA.


Mixed lymphocyte/tumor-cell interaction in a murine sarcoma virus (Moloney)-induced tumor system. Comparison between lymphoproliferation and lymphocyte cytotoxicity. Studies of the MLTI were performed in a primary MSV-induced tumor system. Reactivity against mitomycin-C-treated RBL-5 cells could be detected during a limited period at about 14 days after virus injection. The degree of reactivity of MSV 14 spleen cells was quite variable; stimulation indices ranged from 2.2 to 9.4. Activity in the MLTI appeared to a great extent to be dependent on T-lymphocytes. A relatively broad spectrum of specificity was demonstrated in experiments using additional stimulating cells besides RBL-5. The kinetics of the MLTI correlated well with the kinetics of the primary cytotoxic response in the CRA against RBL-5 cells. However, positive results in the in vivo and in vitro secondary cytotoxicity assays could be detected between 21 and 100 days after MSV injection when the MLTI was negative. Transplantation resistance against challenge with RBL-5 tumor cells also persists for a long time after MSV inoculation. Our data therefore indicate that the MLTI, in contrast to the secondary cytotoxicity assays, does not correlate well with the status of in vivo immunity.


Alteration of the cell membrane architecture during suspension and monolayer culturing. Using suspension-growth-adapted HeLa (S3) cells, we followed the alterations in cell morphology during attachment and spreading on a glass surface in vitro by scanning electron microscopy. Suspension cultivation obviated the need for trypsinization or EDTA treatment of the cells before seeding, thus the cell surface was not chemically altered. The suspension-grown cells were sperical and covered with microvilli. Three hours after seeding into stationary culture, attached cells had surface blebs and large processes, but no microvilli. During the following 9 h, the surface topography altered stepwise producing a complex lamelloplasm. The paper discusses how these membrane events are related to the cell cycle and metastasis.


Graduates and splitees from therapeutic community drug treatment programs: a comparison. As greater numbers of drug abusers seek treatment and drug rehabilitation program resources become more and more scarce, selection processes should become based on scientific research rather than on the intuition of a few influential personnel. Many therapeutic community drug treatment programs have a preferential policy for accepting voluntary over court-ordered commitments. Our findings indicate that such a policy discriminates against those individuals who are most likely to succeed in completing their treatment. Our data also indicate that the success of male drug addicts in completing therapeutic community drug treatment programs is associated with sociological variables. The success of women, on the other hand, is more associated with psychologically oriented concerns.


Interpersonal relationships in heroin use by men and women and their role in treatment outcome. The majority of both male and female heroin addicts entering a city treatment program were introduced to heroin by a male. But by contrast with the males, females were in many cases introduced to heroin by another woman, more often used drugs with persons of both sexes, and were more likely to be living with a current or former heroin user at intake. Encouragement to give up drugs was reported more frequently by both men and women than attempts to discourage their entry into treatment, but only the encouragement of the spouse or opposite-sexed partner was significantly related to treatment outcome.


Contingent naloxone treatment of the narcotic addict: a pilot study. In a community-based abstinence program, 108 chronic heroin abusers, paroled from Maryland correctional institutions, were administered the narcotic antagonist, naloxone, in escalating 500 mg dosages to a daily maximum dosage of 2,000 mg when either urine analysis indicated narcotic drug use or unexcused absences led to the suspicion of narcotic intake. Dosage was then continued at the maximum level until the record again indicated abstinence. This approach was regarded as such a distinct departure from customary antagonist administration that a pilot investigation of its effectiveness was undertaken. Six month outcome data on all patients were constrasted with those of an historical comparison group previously treated in the same clinic without naloxone administration. Both groups were equivalent on all criminal history, demographic, and prognostic variables. The group receiving contingent naloxone administration showed a significantly lower institutionalization rate (8%) than that for the reference sample (37%). Complete abstinence rates were also in favor of the naloxone group (38 vs. 12%).


Demographic characteristics of groups classified by patterns of multiple drug abuse: a 1969-1971 sample. Patient characteristics are described in relation to pretreatment usage combinations of eight classes of illicit drugs for 11,380 drug abusers admitted between 1969 and 1971 to drug treatment centers participating in the NIDA-TCU Drug Abuse Reporting Program. From these data, nine basic patterns of drug use were defined. The most frequent, involving the daily use of heroin or other opioids only, characterized 27% of the patients. Four patterns involving heroin (at least weekly) with various combinations of cocaine, barbiturates, and marijuana accounted for another 29%, two patterns of polydrug use (three or more nonopioid drugs, with and without opioids daily) included 16%, and the remaining 28% of the patients were represented by patterns of a less specific nature. The distribution of patients across drug-use patterns was unrelated to sex, but was associated with race-ethnic background and age.


Incidence of daily drug use as reported by a population of Thai partners working near United States military installations: a preliminary study. A survey of 497 women, all of whom solicited partners from among American soldiers, indicated that 15% of this Thai population uses drugs and/or alcohol daily. Since behavioral observation made during this interview, as well as inconsistencies in responses on the survey, strongly suggested a reluctance to report drug use, it is judged that reported drug use represents an underestimate of true daily usage rate. The influence of transactions between these Thai women and their American associates upon drug use in each group was assessed from the perspective of the Thai informants. There appears to neither a great deal of drug use by Americans induced by interpersonal relationships with these Thai women, nor a great deal of Thai drug use which can be directly attributed to the influence of American soldiers. Alternate methods of data collection are suggested to substantiate this finding. An in-depth study of the relations established between these respondents and their American partners is planned to better interpret these results.


Doxepin: a useful adjunct in the treatment of heroin addicts in a methadone program. An uncontrolled trial of doxepin as an adjunct to treatment of heroin addicts in a methadone program was performed over a 14-month period. Approximately 10% (27) of the program's population utilized a mean of 73 mg of doxepin, usually briefly, and beneficial results were noted in 93% (25). One adverse reaction occurred. No instance of habituation or addiction was noted. A controlled study is warranted to confirm the impression that doxepin represents a useful adjunct in the treatment of heroin addicts in a methadone program.


Alcoholism as blaming the alcoholic.

Alcoholism as blaming the alcoholic. Theories of alcoholism tend to blame the alcoholic by implying that most American drinkers have an ability, which the alcoholic lacks, to drink without problems. The presence or absence of this ability or capacity presumably accounts for the incidence of alcohol problems in society. But we normally apply the idea of an ability or a capacity only after an individual has been exposed to the risk of problems from a hazard or difficult task, and when an individual avoids these problems by their efforts. On this point survey data reveal that most American drinkers have a rather limited exposure to alcohol and are not at risk for problems. It is likely that it is this low exposure to alcohol-rather than some drinking ability-that accounts for the absence of problems. Moreover, the entire practice of treating drinking and the occurrence of problems in the idiom of individual abilities, capacities, or control can be shown to be incorrect and is systematically misleading. A public health approach to alcohol problems is needed that identifies the risks for all associated with hazardous intakes of alcohol and that seeks to reduce these hazards chiefly by reducing the overall consumption of alcohol.


Drug flashbacks. II. Some additional findings. A subsample was drawn from an earlier collection of data in order to answer a number of questions related to "acid" (LSD, STP) flashbacks. Acid users who reported flashbacks also reported significantly more marijuana use than those who did not; the two groups did not differ on use of other drugs, including acid. Simple correlations and multiple regression analyses both showed extent of marijuana use to be the only drug variable significantly related to acid flashbacks. No optimal combination of marijuana and acid improved flashback prediction. Among acid users, correlations between amounts of use for various drugs were high and significant, excepting only the marijuana-acid correlation.


Drug patterns in the chronic marijuana user. The study examined the drug patterns and attitudes of a heavy marijuana user sample drawn from the local "counter-culture." The results indicate that the heavier marijuana user has a different subjective attitude and perception of the drug's effect than a light user. Second, multiple drug usage is, in general, the current and accepted mode within the sample. Finally, it appears that age of initial usage of a specific agent, duration, frequency of usage, and perceived drug effects may be dependent variables with reference to heavy marijuana and multiple drug usage. With respect to these variables, the question arises concerning what proportion of lighter drug using samples may, with time, adopt heavier and more varied drug patterns.


The personality of the cigarette smoker: some empirical data. Smokers and nonsmokers are compared in terms of (1) psychological needs, (2) self-descriptions, (3) self-esteem, (4) academic achievement in high school and college, and (5) marijuana use. On the EPPS smokers scored significantly higher on the needs for Autonomy (p less than .01), Change (p less than .02) and Heterosexuality (p less than .05), while nonsmokers scored higher on the needs for Achievement (p less than .05), Deference (p less than .001), and Order (p less than .001). Smokers rated themselves as being more sociable (p less than .05), while nonsmokers rated themselves as being more careful (p less than .05) and reliable (p less than .05). While the two groups did not differ on a measure of self-esteem, smokers were found to have lower grades in high school (p less than .05) and college (p less than .01) and to be more likely (p less than .0001) to use marijuana. These findings are compared to the results of previous studies and the need for future research is discussed.


Addiction to diazepam.

Addiction to diazepam. Literature is reviewed which raises the question of diazepam's addicting potential. To explore this issue, 50 subjects referred from medical, surgical, and psychiatric clinics were evaluated by interview regarding their use of diazepam. Replies to a standardized interview were combined with physicians' ratings of addiction under two conditions: without and then with the knowledge that the drug in question was diazepam. A computer-aided analysis of these data, including a correlation matrix, revealed surprisingly strong evidence for diazepam's capacity to elicit tolerance and withdrawal in this sample. Psychiatric patients were no more "addiction-prone" in this regard than patients given diazepam for medical conditions. Of equal significance, physicians' impressions of addiction were significantly altered toward a more favorable view when they learned that the drug in question was diazepam. Implications for psychiatric and medical practice are discussed, and suggestions for further controlled research offered.


Inhibitory effect of an intravenous glucose load on basal and insulin-stimulated gastric acid secretion in man. The effect of intravenous glucose on basal and insulin-stimulated gastric acid secretion was investigated in a crossover study on four healthy subjects. Acid output was measured by means of intragastric titration and a telemetering capsule; serum-gastrin and blood glucose levels were measured in 15-minute-intervals. Two different experiments were carried out on each subject. After one basal hour in series (a), 2 ml saline, and in series (b), 0.2 U/kg b. w. glucagon-free insulin were injected intravenously. Two hours later, in both series 0.66 g/kg b. w. glucose were given by rapid i.v. infusion, and the experiment continued for another hour. Hyperglycemia was found to depress significantly basal as well as insulin-stimulated acid secretion, while serum-gastrin levels showed no systematic variation. On the basis of these findings and of earlier studies in animals, it is concluded that the inhibitory effect of hyperglycemia is due to a central action, i.e., an increased activity of the satiety center.


Inhibition of prostaglandin potentiated formalin induced arthritis with non-steroid antiphlogistics. The PGE2 potentiated formalin arthritis can be only temporarily influenced by indomethacin. Azapropazone had a good therapeutic effect on chronic inflammation. According to the enzyme histochemical studies, azapropazone enhanced oxidative enzyme activity. This phenomenon may be interpreted as a sign of a favorable effect.


Probenecid and the rat kidney: investigations by renal enzyme excretion technique. Probenecid in doses of 640 mg/kg was administered to rats by the oral route, and the changes in five important enzymatic activities of urine were recorded thereafter for two days. The resluts exclude that probenecid impairs tubular reabsorption of low molecular weight protein, as urinary muramidase activity was not found increased. On the other hand, increased activities were encountered in those enzymatic activities in urine which derive from the renal tubular cells (ALD, G-6-PDH, LDH). These observations point towards a nephrotoxic effect of probenecid, which, however, is only of very low degree, as other "standard" enzymatic activities of urine, such as alkaline phosphatase, remained unchanged.


Application of a simple fluorometric method on absorption of canrenone. The absorption of canrenone, the major metabolite of spironolactone, was studied by a simple fluorometric method in 30 healthy subjects. Two different pharmaceutical formulations were compared on absorption, and only a negligible difference was found between the micronized and balled-milled form. Canrenone in both formulations was well absorbed, whereas spironolactone absorption was slower. Mattingly's fluorometric assay proved to be a simple method to evaluate the absorption of canrenone.


[Concentration course of Na-Penicillin G in wound secretions following vascular surgery]. After infusion of 10 and 20 M.I.U. of Na-penicilline G, the concentrations in serum, wound exudation, and urine were analysed, at equal points of time, following vascular reconstruction; pharmacokinetic data were calculated as well. The importance of local concentration of antibiotics for therapy and prevention of infections is emphasized - according to pharmacokinetics - in relation to the blood level. Simultaneously, the influence of pathological changes is discussed and represented by a brief case follow-up.


[The influence of xanthinol nicotinate and of a hyperosmolar solution on the motility of the colon]. The effect of Xantinol nicotinate and of hyperosmolar solution upon colonic motility of man was examined in five patients with tranverse preternatural anus by means of intraluminal tonometry. During these examinations, a clear increase of the normal colonic motility could proved as caused by Xantinol nicotinate. According to previous animal experimental tests, and also based on our own clinical experiences, Xantinol nicotinate may be recommended for surgical practice as a reliable stimulant for colonic motility.


Intestinal peptidase activity following whole-body irradiation in mice. Dipeptidase activity (Gly-L-Leucine, L. Leu-Glycine, Gly-L-Phe, L Phe-Gly) was measured in the cytoplasmic fraction of the small bowel mucosa of mice eating three synthetic, defined formula, diets or Purina Chow. The activity/milligram protein of all peptidases was found to be reduced seven days after the last of six weekly exposures to 400 rads (Cobalt 60). The magnitude of reduction varied from half the control value for L-Leu-Glycine peptidase to between one fourth and one fifth the control values for the other three peptidases. These findings may partly explain the improved tolerance to radiation in mice eating a diet containing amino acids (protein hydrolysate) instead of whole protein.


Comparison of renal excretion of chloramphenicol in patients with chronic pyelonephritis, glomerulonephritis and polycystic kidneys. In patients with chronic pyelonephritis, glomerulonephritis and polycystic kidneys, decrease in renal clearance of chloramphenicol (CCHL) is related to a decrease in the clearance of inulin (Cin). The rate of decrease of CCHL is relatively slower than that of Cin. The findings attest to an increased excretion of chloramphenicol by residual nephrons. The groups investigated did not display any significant differences in the relation between CCHL and Cin. The findings indicate that changes in the excretion of chloramphenicol by residual nephrons are not related to the primary pathological process responsible for the impairment of the renal parenchyma.


The human biotransformation of nalidixic acid. Authors have developed new chemical methods for studying the human metabolism of nalidixic acid. The methods are suited for the quantitative determination of nalidixic acid, hydroxynalidixic acid, nalidixic acid glucuronide, hydroxynalidixic acid-glucuronide, and of free and total glucuronic acid excretion. The total urinary excretion of NA and its metabolites was found to be 50 to 100% of the ingested dose. The percentual distribution of the individual metabolites was as follows: NA 0,5-5, HNA2,5-6, NAG24-80, and HNAG11-26%. It was unanimously proved by enzymatic decomposition and specific chemical reactions that the excreted conjugates were monoglucuronides. The significance of individual differences, bilirubin metabolism, urinary pH and the pharmacokinetical behaviour of the individual metabolites is discussed from the therapeutic view.


Effect of tuberculostatic agents on the response of serum growth hormone and immunoreactive insulin to intravenous tolbutamide, and on the half-life of tolbutamide. The effect of drugs used in the chemotherapy of tuberculosis on blood glucose, serum immunoreactive insulin and serum growth hormone, and on the half-life of tolbutamide, were studied in 16 patients with tuberculosis just before starting treatment and four weeks later using an intravenous tolbutamide test. The maximum fall of blood sugar was about 30% on both test occasions. The peak values of serum growth hormone before and after treatment (15.6+/-3.1 ng/ml and 17.3+/-2.9 ng/ml), and the maximum values of serum insulin before or after treatment (37.6+/-5.3muU/ml and 45.6+/-7.0 muU/ml) did not differ significantly from one another. The levels of serum insulin remained slightly higher in the test from 10 minutes onwards after treatment than before, but this was not associated with any particular tuberculostatic drug combination. The half-life of tolbutamide decreased by 43% and the serum concentration of tolbutamide decreased at 180 minutes by 30% and at 360 minutes by 49% after treatment in comparison with the pretreatment values in the patients receiving rifampicin in their drug combination. In patients receiving other tuberculostatic agents, no significant changes were observed.


Measurement of blood flow in skin with an intact vascular pedicle. An experimental model was devised to confirm directly the validity of total skin blood flow measurement, as postulated by Sejrsen. A section of skin in the groin of the rat was prepared, which contained an intact artery and vein. Both of these were direct branches of the femoral vessels. When 133Xe was injected intradermally in saline solution, it was demonstrated that a sham isolated vascular pedicle cleared the isotope, and that the clearance was biexpoential, suggesting two compartments. When the vascualr pedicle was ligated, thereby removing direct blood flow to the piece of skin, the 133Xe clearance curve was monexponential. It is concluded that the rapid portion of the biexponential clearance curve, as analyzed by Sejrsen, does represent the dermal vascular components of isotope clearance, and that measurement of cutaneous blood flow by this method is a valid and useful technique. Results using this technique to follow rejection in a new skin transplant model are presented.


Trichophyton violaceum infection in an Indian school. Trichophyton violaceum infection was found in 26% of 69 children attending a public boarding school. The possible source of infection may have been the adult women from the gypsy community discussed. Treatment with systemic griseofulvin and external sulphur salicylic ointment eliminated the infection in all affected individuals.


Clofazimine in dermatology.

Clofazimine in dermatology. In dermatology, patients with nodosum leprosum and discoid lupus erythematosus are benefited by clofazimine therapy. Its use in other autoimmune diseases has to be considered. Patients with lupus pernio may respond to this regime, but further prolonged trials will have to be undertaken.


A study of thirty right hepatic arteries. Thirty right hepatic arteries discovered among 137 celiomesenteric angiographies show the high frequency (22%) of this variation. Radiologic anatomy of the right hepatic artery was discussed; with the exception of one atheromatous stenosis, the pathologic findings of the right hepatic artery and its terminal branches illustrate the development of a regional disease (12 cases or 40%). This assumed pathology is divided half in pancreatic causes (neoplasm, pancreatitis, pseudocysts) and half in hepatobiliary causes (metastatic cancer of the liver, cancer of the hilus, cirrhosis, hydatid cyst, alveolar echinococcosis or angioma). Five times the surgical technic was modified because of the right hepatic artery. Since these observations were made, we are studying the consequences of this hepatic artery over surgical technics and the approach to the various segments of this artery.


Anti-herpes activity of adenine arabinoside monophosphate. Adenine arabinoside monophosphate (Ara-AMP) demonstrated antiviral activity equivalent to adenine arabinoside (Ara-A) against herpesvirus Types 1 and 2 in tissue culture. Against established herpes virus Type 1 epithelial keratitis in rabbits, Ara-AMP 2 per cent was comparable in efficacy to Ara-A 3 per cent, and Ara-AMP 20 per cent was superior to Ara-A 3 per cent. These results are especially significant in that Ara-A's high solubility will permit (1) more concentrated formulations to be presented topically and (2) adequate absorption by parenteral routes with smaller fluid loads than required for Ara-A.


Deposits of mucosubstances on the cornea by topical chloramphenicol: an electron microscopic study. Chloramphenicol was instilled into rabbit eyes and five days later the corneal surface was examined by scanning electron microscopy. The corneal surface was roughened and showed a proliferative appearance. Examination of thin sections of the cornea by transmission electron microscope showed that the corneal surface stained strongly with alcian blue. It was thus supposed to be a deposit of mucosubstances. Mucosubstances increase pathogenicity of bacteria and, therefore, this deposit may accelerate Pseudomonas keratitis after chloramphenicol application.


Dissecting ocular tissue for intraocular drug studies. This report describes a convenient reproducible ocular dissection technique which has important applications for ocular antimicrobial penetration studies. Different ocular tissues can be sectioned while frozen and then plated directly on culture medium containing the test organism; after the zones of bacterial inhibition are measured at 18 hours following incubation, the tissue specimens are weighed providing more reliable evidence regarding drug concentrations. In such a fashion, a drug can be administered topically, subconjunctivally, or systematically, and assayed from the cornea to the optic nerve at various time intervals. Analysis of antibiotic in the vitreous body, which has important application in the therapy of endophthalmitis, can be routinely performed in the experimental model.


Chlorampenicol retention on, and penetration into, the rabbit eye. The retention of the antibiotic chloramphenicol on, and penetration into, the rabbit eye has been compared following administration in two vehicles. Samples were taken of both aqueous humor and a washing fluid applied to the conjunctival surface and the concentration of 14C-chloramphenicol determined. Greater tear film and aqueous humor drug concentrations, which are effective against many organisms, were found with a vehicle which enhanced retention time on the ocular surfaces.


Steroid metabolism in ocular tissues of the rabbit. The metabolism of cortisol and other steroids was studied in normal untreated rabbit iris-ciliary body and cornea as part of an investigation into the mechanism of glucocorticoid-induced glaucoma. Cortisol is readily converted to the inactive metabolite cortisone by these eye tissues indicating the presence of an 11beta-oxidoreductase system. This reaction is reversible with cortisone being converted to cortisol in the presence of appropriate cofactor. However, due to the absence of a (or as yet undetectable) cortisol-A-ring-reductase system (rate-limiting reaction) the steroid is not irreversibly metabolized to biologically inactive compounds. The 11beta-oxidoreductase system readily converts other C21-11beta-hydroxysteroids, such as corticosterone, to its appropriate C21-11-ketosteroid (11-dehydrocorticosterone). Some C21-steroids lacking the 11-hydroxyl group (11-deoxycortisol, 11-deoxycorticosterone) remain virtually unmetabolized (exception to this was found with progesterone). Evidence of a C21-steroid A-ring reductase system was found only when cortisone and progesterone were used as substrates. However, testosterone a C19 steroid was converted to clearly identifiable A-ring reduced and 17beta-and 3alpha(beta)-oxidoreduced metabolites, thus indicating the presence of testosterone A-ring reductase, 17beta-and 3alpha(beta)-oxidoreductase systems in the eye tissues studied. The presence of a steroid 5alpha(beta)-reductase for some steroids but not for cortisol indicates a distinct substrate specificity for this enzyme system in the eye tissues.


Components of vitreous-soluble proteins: effect of hyperoxia and age. In young puppies, the retina, which is incompletely vascularized at birth becomes fully vascularized at approximately four weeks of age. During this period of vessel growth the total content of vitreous-soluble protein was found closely associated with the rate of retinal vessel growth. As vascularization progressed toward completion, the protein originally present at birth decreased to a negligible or undetected amount. Intravitreal neovascularization was produced in young puppies by exposure to 85 per cent oxygen for four days, then removal to room air. This form of neovascularization resembles closely that observed in human proliferative diabetic retinopathy. The oxygen treatment, which initially produced retinal capillary closure, then neovascularization, was associated with a retention of vitreous-soluble protein at a high level for several days. The results raise the possibility that the vitreous protein(s) may be fundamentally involved in the process of normal vascularization of the retina and in retinal neovascularization.


Essential fatty acid deficiency and renewal of rod outer segments in the albino rat. Biochemical studies in albino rats fed a lab chow diet (control) showed a 9 to 10 day turnover time for rhodopsin in rod photoreceptor membranes, whereas the turnover time in animals raised on a fat-free diet (experimental) was not easily measurable. The number of phagosomes in the pigment epithelium of the control group was three times that found in the experimetals. These studies support earlier autoradiographic data which suggested that the renewal of new photoreceptor discs in the rat retina is controlled by the availability of polyunsaturated fatty acids.


Bradykinin-induced changes in caliber of portal vein during splanchnic angiography. The caliber of the portal vein was investigated in two groups of patients subjected to celiac and mesenteric angiography. In one group, 10 patients (the controls) two angiographic series were performed without giving any pharmacon but the contrast medium. In the other group, 20 patients, also two angiographic series were performed but bradykinin 10 mug was given in the superior mesenteric artery before the second series. Injection of bradykinin resulted in a dilation of the portal vein in 18 of 20 patients, while there was no change in portal caliber in the controls.


Effect of bradykinin on portal pressure and protal caliber in the dog. An experimental angiographic study. Portal pressure and caliber of the portal vein was examined in dogs after bradykinin injection (0.5 mug/kg bodyweitght) into the superior mesenteric artery. Ten experiments were performed. The portal pressure rose from a mean of 10.4 cm H2O to a mean of 21.2 cm H2O after bradykinin injection. The portal vein was dilated in 8 of the 10 experiments. Also the portal circulation time was calculated and decreased after bradykinin injection. Thus, because of the increase in portal pressure and increase in portal circulation care should be exercised when injecting bradykinin into the superior mesenteric artery in patients with portal hypertension and imminent bleeding from oesophageal varices.


Gallium-67 citrate in cerebral infarction. Cerebral scans were obtained on 30 "stroke" patients first with 99mTc pertechnetate and subsequently with 67Ga citrate. Of the 26 patients with abnormal 99mTc static scans, 17 (65%) showed the same abnormality in gallium citrate scans also. In 4 patients with positive technetium flow studies but negative static scans, no abnormality was seen in the scans obtained after gallium citrate injection. In none of the patients was the relative concentration of radioactivity in the lesion greater in the gallium image than in the technetium image. This study proves the nonspecificity of gallium citrate and thus its inability to differentiate cerebral tumor from cerebral infarction just on the basis of localization of gallium.


Velocity of left ventricular wall motion determined by fluoroscopic videodensitometry. A noninvasive method for evaluating myocardial contractile state. Videodensitometry of the margins of the fluoroscopic image of the left ventricle (LV) was used to evaluate LV wall motion and differentiation of the wall motion signal reflected velocity of LV contraction (dV/dt) during various inotropic interventions in six anesthetized dogs. During these interventions heart rate, afterload and preload were maintained constant. Alterations in dV/dt were similar to changes in simultaneously measured LV peak dP/dt and the quotient of dP/dt and developed LV pressure, two widely accepted parameters of LV contractile state. Wide variations in preload and afterload caused no significant changes in dV/dt. Thus, the current study indicates that fluoroscopic videodensitometry provides a specific and reliable noninvasive method for evaluating LV contractile state.


Saturation kinetics of iopanoate in dogs with an intact enterohepatic circulation. Before and after phenobarbital induction. Capacity-limited elimination of sodium iopanoate and a reproducible apparent transport maximum (Tm) were demonstrated in nonoperated dogs having an intact enterohepatic circulation and normal endogenous bile salt pool. Using a multiple infusion technique, estimation of apparent Tm of iopanoate in the liver was possible without sampling either bile or urine. Values obtained for apparent Tm of iopanoate in dogs with normal bile salt pool were similar to those obtained in studies of dogs with chronic bile fistulas. Use of this technique in 4 dogs demonstrated that pretreatment with phenobarbital significantly increases apparent Tm of iopanoate.


Some contractile and electrophysiologic properties of the periurethral striated muscle of the cat. Evidence for differences between the periurethral striated muscle and external anal sphincter of the cat is provided by measurement of the contractile properties in situ and in vitro and the electrophysiologic properties in vitro. In the periurethral striated muscle, the contractile pressure response was faster, d-tubocurarine sensitivity was greater, d-tubocurarine blockade had a shorter duration, and fatigue was faster but not uniquely fast as compared with results for the external anal sphincter. These results suggest that the periurethral striated muscle has similar characteristics to certain fast twitch muscles. Effect of succinylcholine on the periurethral striated muscle and external anal sphincter was similar. Miniature end-plate potentials had large amplitudes which appeared to be correlated to the small diameter of the periurethral striated muscle fibers. Since only focally distributed miniature end-plate potentials could be found, true physiologically slow muscle fibers were absent.


Urinary cytology automation. Preliminary studies with acridine orange stain and flow-through cytofluorometry. Preliminary results are reported in an ongoing program to develop automated cytologic examinations for the detection of bladder cancer from exfoliated urinary epithelium. A metachromatic fluorescent dye, acridine orange, was used to stain the cells in suspension in such a way that their nuclei (DNA) fluoresced green in blue light, and their cytoplasm (chiefly RNA) fluoresced red. The intensities of green and red fluorescence per cell were measured for up to 5000 cells per sample by a flow-through cytofluorometer, and differences were found between cell types that served to identify bladder epithelial cells, leukocytes, squamous cells, and other particulates. Benign and malignant bladder epithelial cells differed principally in their cytoplasmic RNA staining intensity, and methods are discussed for amplifying this and other differences that may be of diagnostic value in an automated instrumental system.


Ureteral function. III. The catheter and the geometry of the ureter. The geometry of a canine ureter with and without the presence of an indwelling catheter has been studied after in vivo freezing and sectioning. Changes in ureteral cross-section were observed as catheter size was increased from about 2 Fr. through 6 Fr. using a new microphotographic procedure. These preliminary results indicate direct contact between the ureteral wall and catheter during ureteral contraction, relaxation, and inactivity. In the region of a urine bolus, an open lumen could be clearly observed. The shape of the lumen appears to depend on the bolus volume, the size of the catheter, and local muscular characteristics of the ureteral wall. In the absence of a catheter, the lumen appears to vary between a totally collapsed configuration and an almost circular shape.


The role of serum albumin in the hepatic excretion of iodipamide. The contrast agent for biliary tract visualization, iodipamide, is strongly bound to serum albumin. The relationship between the affinity of the contrast agent for albumin and its preferential uptake and excretion by the liver has been unclear. The role of serum albumin on hepatic uptake and excretion of iodipamide therefore was investigated on the isolated perfused rabbit liver. With the perfusate containing fully reconstituted rabbit plasma protein or 3.5 g/100 ml rabbit albumin alone, the iodipamide excretion is initially extremely slow. It then increases gradually to about 6 mug/gm liver per min by 60 minutes and thereafter remains constant. The half-time of transfer to the bile is about 130 min. Without albumin in the perfusate the initial clearance rate of iodipamide is rapid, with half-time transfer to the bile of about 40 min. Rabbit serum globulins have no effect on iodipamide excretion. Thus, binding of iodipamide to albumin retards the transfer of iodipamide from plasma to the bile, probably due to competition between albumin and the anion binding protein of the liver.


Dissolution of struvite urinary stones. Experimental studies in vitro. Previous studies from our laboratory have shown that struvite crystals form primarily as a result of urease-induced alkalinity and supersaturation. In vitro perfusion of struvite crystals with undersaturated urine caused crystal dissolution. The investigations reported herein demonstrate complete dissolution of human struvite urinary stones during 6 weeks of perfusion in vitro with undersaturated human urine. Human hydroxyapatite stones perfused similarly underwent only slight dissolution. A glycoprotein precipitated as the stones dissolved; the pathogenic significance of the glycoprotein is unknown.


The location of increased resistance to portal blood flow in obstructive jaundice. The simultaneous measurement of wedged hepatic venous pressure and portal venous pressure at 11 and 28 days following common bile duct and intrahepatic bile duct obstruction reveals a significant elevation of the portal pressure at 28 days which is due primarily to increased presinusoidal resistance to portal blood flow. Portal venograms performed prior to sacrifice revealed moderate narrowing of the portal vein radicles and delayed emptying at 11 days and severe morphological alterations at 28 days. These results confirm the findings of other investigators and help to explain why the hemodynamic alterations occur so rapidly in obstructive jaundice, well before the development of significant biliary cirrhosis.


Study on the efficiency of electric stimulation of the pelvic floor. The continuous electric stimulation of the anal sphincter leads to the onset of a very quick fatigue of the muscle, with a progressive decrease of the amplitude of contraction after 15 min of stimulation. Under the same experimental conditions intermittent stimulation leads to a sustained contraction amplitude. Ts and Tr combinations that can give efficiency rates of contraction above 80 per cent were defined. The results of this study could be applied when intermittent electric stimulation of the pelvic floor is indicated for the treatment of anal or urinary incontinence.


New studies with intravasal devices. The soft valve. In contrast to the results that were obtained with rigid ended prosthetic devices, effective sperm transport occurred for prolonged periods of time through the IITRI Vas-Valve, which had soft silicone rubber flexible end tubes when implanted in the vasa deferentia of dogs. Such transport could be halted by device occlusion with stainless steel springs or with shuttle stem valves. Opening the devices resulted once more in the passage of spermatozoa as well as the production of offspring, indicating that these devices have the potential for being useful as a human male contraceptive method. More research needs to be performed to determine why there is an over-all decrease in sperm output after device implantation and to evaluate and adverse side effects of such devices. The presence of Dacron velour-covered suture rings on the devices permitted effective tissue ingrowth and prevented leakage or recanalization in all cases.


The generation of formaldehyde from methenamine. Effect of urinary flow and residual volume. The antimicrobial effect of methenamine in urine is dependent upon: (i) the rate of generation of formaldehyde; (ii) the concentration of formaldehyde achieved; and (iii) the duration of bacterial exposure to formaldehyde. Studies utilizing an in vitro model which simulates the dynamics of the urinary tract showed that bacteriostatic concentrations of formaldehyde (greater than or equal to 25 mug per ml) were obtained from attainable concentrations of methenamine at urine pH 5.7 to 5.85. Reduced urinary flow rates and large residual volumes increased formaldehyde concentrations and would appear to provide prolonged bacterial exposure to the formaldehyde.


The ureterovesical junction of the rabbit. Twelve New Zealand rabbits were studied for ureterovesical reflux. Dissections revealed the intramural ureter and ureterovesical junction to follow an upward and medial course, unlike the course observed in man. This course could not be altered or distorted by dissection of the bladder base or ureter, by freeing the urether retroperitoneally, or by changing the position of the animal.


Alterations in the red blood cell membrane and the effect of vitamin E on osmotic fragility in beta-thalassemia major. Red blood cell membranes from patients with beta-thalassemia major and intermedia had an average of 25% less sialic acids, and a 50% decrease in titratable SH groups, as compared with normal controls. Membranes from 12 of 13 splenectomized patients were less dense and could be clearly distinguished from normal membranes on a sucrose linear density gradient, indicating a change in lipid-to-protein ratio. The impaired osmotic fragility of thalassemic erythrocytes almost returned to normal following administration of vitamin E, a potent antioxidant, in a daily dose of 750 IU for three to six months. These observations provide more evidence that membrane properties of thalassemic red blood cells differ from those of normal erythrocytes, the difference being due, in part, to increased oxidative stress.


Mitral stenosis with pulmonary hypertension. Long-term results after mitral valvotomy. Ten patients suffering from tight mitral stenosis with severe pulmonary hypertension were operated on and followed up for one to nine years after operation. There was no operative or postoperative mortality. Postoperative hemodynamic studies were performed on seven of the 10 patients. One patient was evaluated twice--one month and seven months after surgery. The condition of all patients improved after operation and regression of severe to extreme pulmonary hypertension was documented in the seven patients on whom the hemodynamic studies were repeated. Hemodynamic and clinical improvement was greatest in young patients with a shorter duration of disease and a normal sinus rhythm prior to operation. The results indicate that a severe degree of pulmonary vascular resistance in mitral stenosis is largely reversible, provided that the obstruction is adequately relieved.


A prospective clinicopathological study of 1,108 cases of antenatal fetal death. A prospective clinicopathological study of antenatal fetal death (AFD) showed that in most cases multiple factors were involved and that in about 70% of the cases maternal diseases were responsible for AFD. The main causes of AFD appeared to be toxemia of pregnancy, various diabetic conditions of the mother (60% of the cases), and blood group incompatibility. Closer and more frequent supervision of pregnant women attending the antenatal clinics will enable earlier detection of maternal disease, and thus may be important in preventing AFD. A simplified oral glucose tolerance test for early detection of diabetes should be performed during pregnancy. In every case of AFD, the placenta and the fetus should be sent for pathological examination.


Some physical properties of the Haifa occlusive dressing for burns. In order to evaluate some of the physical properties of the Haifa Occlusive Dressing, which is in use in our Department, temperature, moisture and the transfer of gases were measured. The Haifa Occlusive Dressing does not significantly raise the temperature of the covered burn, nor does it hinder the diffusion of gases, even when wet. Measurements taken from a patient suffering from a deep second degree burn showed that the amount of secretion over a 9-h period was 270 cm3 and the rate of secretion/unit area was 0.0125 cm/h.


[Protection against light in normal and diseased skin]. At the beginning of the holiday season dermatologists are regularily confronted with questions of light protection. Based on these questions and the respective replies the above subject is discussed. The following differentiation has to be considered: Cosmetical light protection. Light protection in case of pathological sensitivity to light. Light protection in case of light dermatoses. Besides a few exceptions (e.g. in the therapy of porphyria and similar diseases) light protection is a physical, absorptive process, i.e. a part of the UV rays is absorbed before reaching the skin. In abnormal light sensitivity, the UVA with longer wave lengths plays a part too, whereas for "normal skin" UVB with medium wave lengths is responsible for the light induced reactions. Details concerning selection, application, and effect of light protecting measurements are discussed.


[Nodular cutaneous amyloidosis. Clinical, histopathological and ultrastructural findings]. A case of nodular amyloidosis cutis of the face with minimal deposits of amyloid in the rectum is reported with respect to clinical, histopathological, and ultrastructural findings. A discussion of the problem of systematization in nodular amyloidoses is included. By electron microscopy, the principal similarity of the ultrastructure of amyloid is stressed again. Amyloid in this case of nodular amyloidosis cutis is thought to be synthesized by plasma cells which are found especially in the growing peripheral parts of the tumors. Fibroblasts with extremely dilated endoplasmic reticulum are almost totally surrounded by the fibrillar masses of amyloid within the tumor. Unusual spindle-formed cisternae of Golgi bodies containing oriented coarse fibrils are found in the fibroblasts. They are thought to represent a disturbance of the secretion of tropocollagen to the interstitium due to the surrounding amyloid masses.


[Diagnostic possibilities using RAST. Correlation with three various skin extracts]. The correlation between RAST and three different commercial extracts referred to allergen and commercial gives a review of the reliability of skin tests (up to 25% false results). The question whether both RAST-discs for house dust and house dust mite have to be used is discussed. The common allergens of house dust mites and the rarer allergens of cats and guinea-pigs are emphasized.


Veterinary medical manpower: supply-demand projections to 2020. A supply projection model to estimate the number of veterinarians available through the year 2020 was developed. When projected available manpower was compared with the need for veterinary medical services, as estimated in a National Academy of Science study, a net shortage was indicated in each year between 1976 and 2020. The manpower supply available if 3 additional veterinary colleges were developed in the United States was also estimated. It was concluded that, even with the additional output of these colleges, the supply of veterinarians will not keep pace with future needs for veterinary services.


Squamous cell carcinoma in dogs.

Squamous cell carcinoma in dogs. In a review of neoplasm registry records at Kansas State University (1961 through 1971), 112 squamous cell carcinomas were reported in 38 breeds of dogs, representing 3.2% of 3,481 neoplasms recorded. Mean age of the affected dogs was 8.3 years. Metastases occurred in 7 dogs. The tumors were removed surgically for biopsy in 104 dogs, 8 of which then had recurrences and required further surgery. The oral cavity was the principal site (18%) of squamous cell carcinomas in the 112 dogs.


Patent ductus arteriosus in the dog: characteristics of occurrence and results of surgery in one hundred consecutive cases. The results of surgical repair of patent ductus arteriosus (100 dogs) were compared with the results of nonsurgical treatment of this defect (14 dogs). The death rate for dogs surgically treated was 8%, with 2 deaths at surgery and 6 late postoperative deaths. In the nonsurgical group, 64% died within one year of the examination. The increased survival rate for the surgically treated group was significant ( P less than 0.001). Surgical death rate was high for dogs more than 2 years old and weighing more than 23 kg. It was concluded that surgery is the preferred method of treatment and that early surgery increases the survival rate of dogs with patent ductus arteriosus, compared with the survival rate for older, heavier dogs with the defect.


Disappearance of spermatoza from the ejaculates of vasectomized dogs. Ejaculates of bilaterally vasectomized dogs contained spermatozoa as long as 21 days after vasectomy, indicating that spermatozoa in the canine ejaculate originated from both the epididymides and the vasa deferentia, not from the epididymides alone.


Amphetamine poisoning in dogs.

Amphetamine poisoning in dogs. Amphetamine intoxication in dogs referred to the Veterinary Diagnostic Laboratory or the Veterinary Hospital of the University of Minnesota was characterized by excitement, agitation, hyperthermia, and convulsive episodes that could be confused with other convulsant poisonings. Extraction procedures on stomach contents or urine enabled indentification of the drug, using ultraviolet spectrophotometry.


The use of freeze-fracture and negative staining techniques to study the ultrastructure of melanosomes isolated from B16 melanoma. Freeze-fracture negative staining methods were used to investigate the structure of melanosomes isolated from B16 melanoma. The findings demonstrated the presence of a melanosomal double-layered membrane. Negative staining procedure showed that the melanosomal membrane is sometimes ruptured, displaced or peeled off during the purification process. Fractured melanosomes showed melanin spheres with a mean diameter of 24 nm. This compares with a mean diameter of 26 nm for the melanin spheres revealed by negative staining. The granular appearance of fractured mature melanosomes is due to the fracture following a random path between melanin spheres.


Experimental production of ridges on rabbit articular cartilage: a scanning electron microscope study. The surface of normal rabbit articular cartilage attached to subchondral bone has a pitted appearance when examined with the scanning electron microsope. It is thought that these pits are similar to those seen in human cartilage and that they reflect the presence of underlying chondrocytes and lacunae, shrunken by preparative procedures. Ridges or undulations were not seen on the normal articular surface with the scanning electron microscope but complex systems of coarse and fine ridges were produced when cartilage was damaged by cutting, by making a hole in it or by detaching it from subchondral bone. Humps or mound-like elevations also developed in some instances when cartilage was damaged by cutting or by making a hole in its substance.


The structural basis of the philtrum and the contour of the vermilion border: a study of the musculature of the upper lip. The course and insertion pattern of muscle fibres in the philtrum of the human upper lip were studied in seven post-mortem specimens using serial histological sections and a reconstruction method using sheets of Plexiglas. The fibres of the musculus orbicularis oris entering the upper lip from one side were observed to decussate in the midline and proceed to insert into the skin of the opposite side lateral to the philtral groove. The philtral ridges appeared to represent the medial borders of bilateral muscle insertion zones of the lip in which the fibres of the m. orbicularis oris raised the level of the skin by splaying out and inserting into it. Contributions to philtral form also came from the musculus levator labii superioris as it descended as far medially as the philtral ridge to insert into the vermilion border lateral to the median groove, and from fibres of the musculus nasalis which inserted into the philtral ridges superiorly. The philtral groove corresponded to the more compact median decussation of the orbicularis oris where lip thickness was also reduced by the relative absence of muscle fibre insertions into the skin. The displacment of the vermilion border giving rise to Cupid's bow appeared to result from the lifting action of the m. levator labii superioris lateral to the median groove in conjuction with a depressor action by the m. orbicularis oris on the median tubercle.


An ultrastructural study of implantation in the golden hamster. I. Loss of the zona pellucida and initial attachment to the uterine epithelium. Forty five blastocysts from 14 golden hamsters were examined in situ with light and electron microscopy between 3 and 4 days of pregnancy (post-ovulation). At 3 days blastocysts remained free within the uterine lumen with their zonae pellucidae intact. At various intervals between 3 days and 3 days 6 hours a gradual thinning of the zona occurred, indicating the possible presence of a lytic factor which aids in the removal of the zona pellucida. Blastocysts at 3 days 8 hours had lost their zonae pellucidae, and by 3 1/2 days they were completely enclosed by the uterine pithelium. By 4 days a more intimate association between the juxtaposed trophoblast and uterine epithelium occurred, leaving intermittent deposits of electron-dense material between the adjoining plasma membranes.


A histochemical study of human fetal skin. Glycogen and alkaline phosphatase have been studied in human fetal epidermis between the 28th and 182nd days of gestation. Early on, bladder cells rich in glycogen and alkaline phosphatase are present in the periderm. After 140 days, however, keratin appears in the superficial layers of the periderm; the bladder cells degenerate and become 'rosette' cells, and glycogen and alkaline phosphatase begin to disappear. It is suggested from this evidence that, in early fetal life, before the onset of keratinization, glucose is absorbed from the amniotic fluid and stored as glycogen in the periderm.


Further observations on the pharyngeal hypophysis and the postsphenoid in the mature male rat. In an investigation into the pharyngeal hypophysis and the postsphenoid using seven hypophysectiomized mature male rats, a pharyngeal hypophysis and a craniopharyngeal canal was found in each of two rats. Cellular differentiation was noted in the pharyngeal hypophysis in both rats. In one rat the pharyngeal hypophysis was markedly larger than any seen to date. In both rats the pharyngeal hypophysis was continuous with tissue of similar histological appearance which extended the full length of the cranio-pharyngeal canal. The histological appearance of the pharyngeal hypophysis and of the specific intra-canal tissue was also similar to that of cystic areas in the sellar adenohypophysis in the normal rat. The data arising from the present investigation indicate that a well-defined cranio-pharyngeal canal can occur in the rat. The data also support the assumption that the sellar adenohypophysis may be continuous with specific tissue within a cranio-pharyngeal canal. The significance of the data in terms of reactive hypertrophy and cellular differentiation of the pharyngeal hypophysis and the specific intra-canal tissue following hypophysectomy must await further data on the volume and histology of such tissue in normal rats which possess a cranio-pharyngeal canal.


Some aspects of amoeboid microglia in the corpus callosum and neighbouring regions of neonatal rats. The distribution and form of amoeboid microglia in the brain of neonatal rats have been studied with the light and electron microscope. With the silver carbonate method of Rio-Hortega, two major 'colonies' of amoeboid microglia are identified: (1) in the supraventricular corpus callosum in which the nerve fibres are widely spaced, and (2) at the medial angle of the lateral ventricle inferior to the corpus callosum. Scattered amoeboid cells are also seen in the cavum septum pellucidum and in the lumen of the lateral ventricle. Associated with the subependyma forming the roof of the lateral ventricle there are also numerous amoeboid cells. Ultrastructural studies show that the subependyma includes cellular elements with features intermediate between those of immature subependymal cells and full-blown amoeboid microglia. It is suggested that the latter are derived from the subependymal cells and that, once they are formed, they leave the subependyma and migrate into the corpus callosum and elsewhere. With the metallic stain, the amoeboid microglia present a wide diversity of appearances, some of which bear a close resemblance to typical microglia. It is therefore suggested that amoeboid microglia change into typical microglia. The present study clearly demonstrates that amoeboid microglia are active phagocytes. Their cytoplasm is heavily loaded with secretory granules (lysosomes) and give a positive reaction with PAS and acid phosphatase.


Observations on the source of embryonic myocardioblasts. The light and electron microscopic appearance of mesenchymal and myoblastic tissue in the embryonic heart is described. The similarity in the morphological appearance of all mesenchymal cells is pointed out, whether they occur in atrioventricular cushion tissue, the ridge tissue of the bulbus, cordis, sub-epicardial tissue or in mesenchyme elsewhere in the embryo. Cells intermediate in their ultrastructure between mesenchymal cells and myoblasts are found. The significance of such cells is discussed and the suggestion made that their appearance is consistent with their representing stages in the differentiation of mesenchymal cells into myoblasts.


A presomite human embryo of Horizon VII. A presomite embryo of Horizon VII aged approximately 18 days is described and illustrated. It is compared with some other embryos of a similar age, and a considerable variation of histological characteristics within the same Horizon is noted.


Quantitative changes in neuroglia in the white matter of the mouse brain following hypoxic stress. Two experimental and one control group of 70-80 day old mice were used in this study. The two experimental groups were subjected to hypoxia for 2 days in a decompression chamber at 390 mmHg. The animals in one experimental group were killed on removal from the chamber (hypoxic group) while those in the other (recovery group) were allowed to recover at sea-level atmospheric pressure for one week before being killed. Semithin, toluidine blue stained sections from the anterior limb of the anterior commissure were examined to find whether any quantitative changes occurred in the neuroglia with hypoxic stress. The following changes were observed: (1) The percentage of astrocytes in the hypoxic and recovery groups was significantly (P less than 0-005) lower than in the control group. (2) The percentage of oligodendrocytes in the hypoxic and recovery groups was significantly (P less than 0-001) higher than in the control group. (3) The percentage of microglia in the recovery groups was significantly (P less than 0-02) lower than in either of the other two groups. (4) The percentage of astrocytes in the recovery group was slightly (2-1%) higher than in the hypoxic group, and although not statistically significant, this result suggested that a slow return to normal might be occurring. (5) Little change was observed in cell density. The possible significance of these changes is discussed. I should like to express my indebtedness to Dr E.J. Clegg of the Department of Anatomy, Sheffield University, for the use of the decompression chamber, for his advice and help in the preparation of the control and experimental animals, and also for his hospitality throughout the duration of the experiments. Thanks are also due to Mrs Sheila Ramsay for her careful preparation of the perfusing fluids, and to Mrs Dawn Alexander for typing the manuscript.


A pilot study of cell production by the ganglionic eminences of the developing mouse brain. Cell production in the medial and lateral ganglionic eminences in pre- and post-natal mouse brains was studied by recording the number, location and plane of cleavage of mitotic figures. The site of maximum cell production shifted progressively from the ependymal layer to an adjacent sub-ependymal proliferative compartment. In the latter, mitosis occurred without the nuclei participating in the migratory movement to the ventricular surface which is characteristic of the nuclei of the ependymal compartment. The sub-ependymal compartment persisted vestigially into post-natal life as the well known sub-ependymal layer.


An experimental analysis of "spillover" effects on the social interaction of behaviorally handicapped preschool children. The effects of prompting and social reinforcement directed to target subjects on their social behavior and that of peers who never received prompting and reinforcement for positive social behavior, were examined. In a combined reversal and multiple-baseline design, three behaviorally handicapped preschool boys who exhibited divergent social behavior repertoires and varied histories with social reinforcement events were sequentially exposed to intervention conditions in order to investigate "spillover" of treatment effects. Prompting and reinforcement increased positive social behavior and decreased negative social behavior emitted by all target subjects. The results also demonstrated a "spillover" effect on two target subjects, who at various times were not under intervention, and on the peers as well. The findings suggest that: (a) the direct and indirect effects of intervention procedures may be enhanced by designing treatment based on the social repertoire and reinforcement histories of the subjects; and (b) the treatment "spillover" effect may be increased by applying procedures to two children at once, rather than at one at a time.


Self-recording in training girls to increase work and evoke staff praise in an institution for offenders. Self-recording procedures were used by four adolescent girls to increase work and comments (cues) that evoked staff praise during vocational training sessions in a maximum-security institution for offenders. The girls were selected on the basis of their not responding to a staff-directed token program. The self-recording procedures were directed by a therapist who saw the girls outside the vocational training sessions. According to a multiple-baseline design, self-recording of work was introduced sequentially to each of the two or three settings the girls attended each day. A few days after work had increased, self-recording of cues was introduced. Tokens were delivered by the therapist for work and cues recorded by the girls. Work and cues increased following self-recording for three of the girls and increased cues evoked higher rates of staff praise. Girl and staff behaviors were maintained during short follow-up periods when tokens were not given for the girls' records. The procedures failed to effect desirable changes with a fourth girl's work and self-recording of work was terminated without introducing cueing.


Contingent observation: an effective and acceptable procedure for reducing disruptive behavior of young children in a group setting. Since a major task of childhood is learning to get along in a group without disrupting other children's activities, caregivers need explicit guidelines for gentle but effective procedures for dealing with disruptive behaviors in child-care settings. In a day-care center for normal 1- and 2-yr.-old children, an effort was made to develop a procedure that appeared sufficiently humane and educational to be acceptable to parents and day-care workers, and yet effective in reducing disruptive play behaviors. Caregivers used the occasion of disruptive behavior to instruct the child in appropriate alternatives, then had the child sit on the periphery and observe the appropriate social behavior of the other children "sit and watch", for a brief period before inviting him or her to rejoin the play activities. The effectiveness of this procedure was compared with a method commonly recommended for the use with young children: instructing the child, then distracting or redirecting the child to an alternative toy or activity. Contingent observation, combining instruction with a brief timeout (from being a participant in an activity to becoming an observer of the activity), proved considerably more effective in maintaining low levels of disruptions and was considered by caregivers and parents to be an appropriate and socially acceptable method of dealing with young children's disruptive behaviors. Therefore, contingent observation can be recommended for general use in day-care programs for young children.


Interactions between teacher guidance and contingent access to play in developing preacademic skills of deviant preschool children. Token-mediated access to play and snacks was made contingent on completion of academic tasks in the Baseline Experiment. This contingency produced stable completion rates that were subsequently doubled, and then tripled, for four deviant children in a special preschool. A reversal design demonstrated that the contingency was functional in maintaining the children's rates of task completion. The Guidance Experiment examined the role of a social event, teacher guidance, in the acquisition of task-completion skills, in a multiple-baseline-across-tasks design (with reversals). The analysis demonstrated that teacher guidance was an important supplement to the token-mediated contingency in establishing significant increases in task completions for a second group of three deviant children in the special class. The importance of teacher guidance was related to the difficulty level of the children's tasks.


Quantitation of o- and p-sulfamoylbenzoic acids in commerical saccharin by high-performance liquid chromatography. Quantitation of o- and p-sulfamoylbenzoic acid residues in saccharin and its sodium salt is achieved by a method comprising methanolic extraction and high-performance ion exchange chromatography. A commercially available anion exchange column was employed with an aqueous buffered (pH 9.2) mobile phase. As little as 80 ppm of the ortho-isomer and 25 ppm of the para-isomer can be accurately determined. The levels of detectability (2 times noise) are estimated as 8 ppm (0.16 mug on column) and 2.5 ppm (0.05 mug on column), respectively. Recoveries from saccharin ranged from 92.7 to 96.5% (ortho) and from 92.2 to 103.3% (para). Recoveries from the sodium salt ranged from 93.1 to 104.4% (ortho) and from 93.5 to 97.8% (para). Of 9 other potential saccharin impurities tested separately, only one was found to interfere slightly in the chromatographic part of the procedure.


Gas-liquid chromatographic determination of famphur and its oxygen analog in tissues of reindeer and cattle. A gas chromatography equipped with a flame photometric detector operating in the phosphorus mode provided a sensitive method for determining residues of famphur, O,O-dimethyl O-[p-(dimethylsulfamoyl)phenyl]phosphorothioate, and its oxygen analog in reindeer and cattle tissues. With extraction and cleanup, 0.025 ppm famphur and 0.06 ppm oxygen analog could be detected in the body tissues. Recoveries of 73-100% were obtained from fat, muscle, liver, and kidney.


Gas-liquid chromatographic determination of 3,6-dichloropicolinic acid in soils. A gas-liquid chromatographic (GLC) method has been developed for the determination of the experimental herbicide 3,6-dichloropicolinic acid (Dowco 290) in soils. The method involves extraction of 1 g soil samples with 1N NaCl at approximately pH 7, methylation with diazomethane utilizing a microgenerator, and detection by electron capture GLC. Interferences are small, so that a cleanup step is not necessary even at the 6 ppb level. The procedure is rapid, requiring only 45 min/sample. Recoveries range from 84 to 94% at the 6-1000 ppb level with a minimum detectable limit of 6 ppb. Standard deviations for the percentage recovery values vary from 10.9 to 2.3 for the tested range of 6.7-670 ppb, respectively.


Comparison of analytical methods for metribuzin. Determinations of the active ingredient in technical and formulated metribuzin were compared by gas-liquid chromatography (GLC) using various solvents, infrared (IR) spectrophotometry, and high-pressure liquid chromatography (HPLC). Ketones could not be used as a solvent for GLC analysis because of Schiff base formation. The GLC method using ethylene glycol monomethyl ether gave results about 1% higher for technical metribuzin than the other methods. GLC using methylene chloride solvent agreed with IR and HPLC results to within 0.4%. GLC using methylene chloride is the preferred method.


Collaborative study of the colorimetric determination of nitrate and nitrite in cheese. A quantitative colorimetric method for the determination of nitrate and nitrite in cheese has been subjected to collaborative study. The method includes clarification of an aqueous extract of cheese with zinc hydroxide, reduction of nitrate to nitrite via a spongy cadmium collumn (the nitrite originally present is unaltered), diazotization of sulfanilic acid with the nitrite, and coupling with 1-naphthylamine hydrochloride to form a pink azo dye whose absorbance is measured at 522 nm. The spectrophotometric responses are compared to a standard curve. In samples containing both nitrate and nitrite, nitrate is determined by difference. A standard deviation of 5.5 was obtained (5 of 6 collaborators) when a cheese sample spiked with 276 ppm sodium nitrate was analyzed by the method. The method has been adopted as official first action.


Collaborative study of a semiautomated fluorometric method for the determination of reserpine in tablets. A semiautomated fluorometric method for the determination of resperpine in tablets was collaboratively studied by 7 laboratories. The method is a modification of the semiautomated method of Urbányi and Stober, which involves formation of a fluorogen with vanadium pentoxide. Collaborators were supplied with 3 composites, each from a different dosage level of commercial tablets. The results obtained agreed well with the AOAC manual fluorometric method; coefficients of variation ranged from 0.45 to 2.70%. The method has been adopted as official first action.


Transport of vitamin B12 in Escherichia coli: common receptor system for vitamin B12 and bacteriophage BF23 on the outer membrane of the cell envelope. We showed previously that the outer membrane of the Escherichia coli cell envelope normally contains about 200 to 250 B12 receptors, and that these receptors function both in B12 transport and as receptors for the E colicins. This paper shows that this receptor system is also shared with bacteriophage BF23. A strong positive correlation was observed between the number of B12 receptors per cell and the rate of adsorption of BF23. Cells from mutant strains that lacked B12 receptors did not adsorb BF23 particles. The rate of adsorption of BF23 to cells of a merodiploid strain (RK4151), with about 550 B12 receptors per cell, was approximately double that to cells of a normal, haploid strain. The adsorption of BF23  to hole cells, cell envelopes, outer membrane particles, and solubilized outer membranes was inhibited by vitamin B12, with 50% inhibition at B12 concentrations in the range of 0.5 to 2.0 nM. These values are close to the observed KS for B12 binding to the B12 receptors. Vitamin B12 concentrations as high as 100 nM did not inhibit adsorption of bacteriophages T5, T6, and lambdacI to cells of sensitive strains of E. coli. Bacteriophage BF23 inhibited B12 transport by whole cells and was shown to be a competitive inhibitor of B12 binding to isolated cell envelope particles. The B12/BF23 receptors from E. coli strains KBT069 (btuB69) and RK4104 (btuB69) were fully active, but the number per cell was reduced to an average value of about 0.5.


Ultrastructure of rigid and lignified forage tissue degradation by a filamentous rumen microorganism. A small (less than 1 mum)-filamentous, branching microorganism was observed in Gram-stained smears of the rumen microflora and was found to degrade tissues in forage samples incubated in vitro and in vivo with rumen fluid and observed by scanning and transmission electron microscopy. The microbe had prokaryotic cytoplasmic features and a gram-positive type of cell wall structure. Round to oval bodies apparently attached to hyphae resembled the sporulation pattern reported for Micromonospora. Filaments and rod and coccal forms of the microbe degraded rigid forage cell walls and lignified, thick-walled sclerenchymal cells. Location of the microbe at a slight distance from the degraded zones suggested the action of extracellular enzymes. The presence of a microbe with the capability of degrading lignified tissue represents an important and unique function in the rumen ecosystem.


Change in quantity of lipids and cell size during intracytoplasmic membrane formation in Gluconobacter oxydans. Electron microscopy previously revealed that Gluconobacter oxydans differentiates by forming quantities of intracytoplasmic membranes at the end of exponential growth. It was also shown that the formation of these membranes appears concurrently with an increased rate of polyol oxidation. In the present study, exponential-phase cells devoid of intracytoplasmic membranes were harvested and the quantity of free lipid was determined. This quantity was compared with that extracted from cells harvested 4 and 16 h into the stationary phase that contained intracytoplasmic membranes. Cells harvested 4 and 16 h into the stationary phase contained 58 and 43% more free lipid per 100 mg of cell weight than found in undifferentiated exponential-phase cells. These same cultures were used to compare the quantity of lipid extracted per cell. This analysis revealed 89 and 142% more lipid per cell in 4 and 16 h stationary-phase cells. Further study demonstrated that cells increased in length and decreased in density with time after they entered the stationary phase. We estimated, however, that intracytoplasmic membrane development in G. oxydans is accompanied by a 57 to 62% increase in free-lipid that cannot be attributed to a change in cell size. These results suggest that the traditional expression of extracted lipid per milligram of cellular dry weight should not be used for comparative purposes during differentiation in gram-negative bacteria, unless it is first established that both cell size and cell density remain constant throughout differentiation.


Occurrence of phosphenolpyruvate carboxylase in the extremely thermophilic bacterium Thermus aquaticus. In the extreme thermophile Thermus aquaticus, phosphoenolpyruvate carboxylase catalyzes carbon dioxide fixation on the C3 metabolite phosphoenolpyruvate, producing oxaloacetate. In a moderately thermophilic Bacillus species this function is fulfilled by pyruvate carboyxlase. Like several of its mesophilic counterparts, the Thermus enzyme exhibits a requirement for acetyl coenzyme A.


Lowered levels of colicin Ia membrane receptors in an Escherichia coli mutant defective in heme biosynthesis. Cells of an Escherichia coli mutant defective in heme biosynthesis (hemA) grown under conditions for respiration deficiency (grown in the absence of aminolevulinic acid) have 20% of the number of specific colicin Ia receptors found in cells of the same strain grown under conditions for respiration competency (grown in the presence of aminolevulinic acid).


Ubiquity of plasmids in coding for toluene and xylene metabolism in soil bacteria: evidence for the existence of new TOL plasmids. Thirteen bacteria have been isolated from nine different soil samples by selective enrichment culture on m-toluate (m-methylbenzoate) minimal medium. Eight of these were classified as Pseudomonas putida, one as a fluorescent Pseudomonas sp., and four as nonfluorescent Pseudomonas sp. All 13 strains appeared to carry TOL plasmids superficially similar to that previously described in P. putida mt-2 in that: (i) all the wild-type strains could utilize toluene, m-xylene, and p-xylene as sole carbon and energy sources, (ii) these growth substrates were metabolized through the corresponding alcohols and aldehydes to benzoate, m-toluate, and p-toluate, respectively, and thence by the divergent meta (or alpha-ketoacid) pathway, and (iii) the isolates could simultaneously and spontaneously lose their ability to utilize the hydrocarbons, alcohols, aldehydes, and acids, particularly during growth on benzoate, giving rise to cured strains which could grow only on benzaldehyde and benzoate of the aromatic substrates by the alternative ortho (or beta-ketoadipate) pathway. Eight of the isolates were able to transfer their TOL plasmids into their own cured strains, but only five were able to transfer them in interstrain conjugation into the cured strains, but only five were able to transfer them in interstrain conjugation into the cured derivative of P. putida mt-2. However, P. putida mt-2 was able to transfer its TOL plasmid into 11 of the cured isolates, and eight of these were able to retransmit this foreign plasmid in intrastrain conjugation with their own cured derivatives. Three of the isolates, MT 14, MT 15, and MT 20, differed significantly from the others in that the wild-type strains dissimilated the p-methyl-substituted substrates poorly, and also, during growth on benzoate, in addition to the cured derivatives, they gave rise to derivatives with a phenotype intermediate between the cured and wild-type strains, the biochemical and genetic nature of which has not been elucidated.


Partial purification and characterization of cytidine 5'-diphosphate-diglyceride hydrolase from membranes of Escherichia coli. Cytidine 5'-diphosphate (CDP)-diglyceride is hydrolyzed to phosphatidic acid and cytidine 5'-monophosphate by a specific membrane-bound enzyme in cell-free extracts of Escherichia coli. The hydrolase can be extracted from the particulate fraction with Triton X-100 and purified 1,000-fold in the presence of this detergent. Several nucleoside disphosphate diglycerides were synthesized to determine the substrate specificity of the hydrolase. CDP-diglyceride was hydrolyzed preferentially, although uridine 5'-diphosphate-diglyceride, guanosine 5'-diphosphate-diglyceride, and adenosine 5'-diphosphate (ADP)-diglyceride were also slowly hydrolyzed. Surprisingly, the purified enzyme did not catalyze detectable cleavage of deoxy-CDP (dCDP)-diglyceride. The liponucleotide pool of E. coli contains dCDP-diglyceride and CDP-diglyceride in approximately equal amounts (Raetz and Kennedy, 1973). Water-soluble nucleoside pyrophosphates, such as CDP-choline, nicotinamide adenine dinucleotide, or adenosine 5'-triphosphate are not attacked by this specific hydrolase. Hydrolysis of CDP-diglyceride is strongly inhibited by adenosine 5'-monophosphate and by ADP-diglyceride.


In vitro system for the synthesis of teichoic acid linked to peptidoglycan. A crude cell wall preparation from Staphylococcus aureus H prepared by the method of Mirelman and Sharon (1972) was shown to catalyze the synthesis of polyribitol phosphate linked to the cell wall peptidoglycan. The reaction used cytidine diphosphate (CDP)-ribitol as a substrate and in addition required the presence of CDP-glycerol, uridine diphosphate (UDP)-N-acetyl-D-glucosamine, and adenosine triphosphate. Incubation of radioactive CDP-glycerol with the crude cell wall preparation resulted in the transfer of glycerol phosphate residues to the cell wall; this reaction was greatly stimulated by the presence of UDP-N-acetylglucosamine. These data suggest that polyribitol phosphate is linked to the cell wall peptidoglycan by an oligomer contaning N-acetyl-D-glucosamine and glycerol phosphate.


Diminution of outer membrane permeability by Mg2+ in a marine pseudomonad. Intact cells of the marine pseudomonad MB-45, in the presence of optimal Mg2+, exhibited little alkaline phosphatase activity as judged by the hydrolysis of p-nitrophenylphosphate. Sonic extracts, in contrast, were rich in this activity. Removal of the loosely bound outer layer did not diminish this crypticity of alkaline phosphatase, but decreasing the concentration of Mg2+ in the suspending medium progressively exposed the alkaline phosphatase. Since MB-45 did not liberate alkaline phosphatase into the surrounding medium even in the absence of Mg2+ and since this enzyme is localized in the periplasmic space, it can be concluded that the crypticity was due to the exclusion of p-nitrophenylphosphate by the outer membrane. Mg2+ is apparently essential for the full expression of this limited permeability.


Distribution and composition of lipopolysaccharides from mycoplasmas. Polymeric carbohydrates containing glycerol and fatty acids were isolated from whole cells and membranes of mycoplasmas by hot aqueous phenol extraction and gel filtration. Lipopolysaccharides were found to occur in four species of Acholeplasma, two of Anaeroplasma, and in Mycoplasma neurolyticum. None were detected in Spiroplasma citri or in five species of Mycoplasma. All lipopolysaccharides contained both neutral and N-acylated amino sugars in ratios varying from 1:1 to 3:1. The neutral sugars found in varying distribution were glucose, galactose, and mannose. The amino sugars included fucosamine, an unidentified deoxyhexosamine, galactosamine, and glucosamine. Fucosamine and glucose were the only sugars common to all lipopolysaccharides. The fatty acids were similar to those found in the lipids of each organism.


Lipid composition and lipid metabolism of Spiroplasma citri. In a horse serum-based medium containing a full complement of fatty acids, cells of Spiroplasma citri were seen to preferentially incorporate palmitic acid. In the same medium, which had a steryl ester-to-sterol ratio of 3.64, a steryl ester-to-sterol ratio of 0.23 was seen in the cells, cholesterol being preferentially incorporated over cholesteryl ester. Like most other mycoplasmas, S. citri was shown to be unable to synthesize fatty acids or esterify cholesterol. The neutral lipids of S. citri grown in a medium containing horse serum consisted of free cholesterol, cholesteryl ester, free fatty acids, triglycerides and diglycerides. All polar lipids were phospholipids, with no glycolipids detected. These phospholipids, which are characteristic of many mycoplasmas, are phosphatidyl glycerol, diphosphatidyl glycerol, and their lyso derivatives. Sphingomyelin was also incorporated when cells were grown on horse serum. A sterol requirement for the growth of S. citri was confirmed using a serum-free medium supplemented with bovine serum albumin, palmitic acid, and various concentrations of sterols dissolved in Tween 80. The addition of palmitic acid stimulated growth but was not essential for growth. S citri was shown to grow best on cholesterol and beta-sitosterol and was able to grow on stigmasterol and ergosterol to a lesser degree. No growth was obtained using mevalonate, deoxycholate, or taurodeoxycholate as an alternative to sterol. S. citri was also able to grow when palmitic acid was replaced with oleic acid, linoleic acid, or linolenic acid. Alterations in the lipid composition of the growth medium and hence in the lipid composition of S. citri induced changes in the characteristic helical morphology of the cells, concurrent with loss of cell viability. Culture, age, and pH were also factors in determining cell morphology and viability.


Production of extracellular ribonuclease by yeasts and yeastlike fungi, and its repression by orthophosphate in species of Cryptococcus and Tremella. A strain of Cryptococcus laurentii and a haploid isolate of Tremella foliacea were shown to produce orthophosphate-repressible ribonuclease in liquid culture. Addition of as little as 1 mM K2HPO4, pH 7.0, completely repressed enzyme production by both fungi. The orthophosphate-repressible enzyme was not produced by other species of the two genera tested. These results, together with other findings, suggest a close phylogenetic relationship between Cryptococcus laurentii and Tremella foliacea. The ability of other yeasts and yeastlike fungi to hydrolyze ribonucleic acid in a solid test medium was assessed. Based on the limited number of organisms available for study, extracellular ribonuclease activity was found in species having close affinity to the Basidiomycetes and in yeasts classified in the ascomycetous genera, Endomycopsis, Hansenula, and Kluyveromyces. Other ascomycetous yeasts did not exhibit extracellular ribonuclease.


Isolation and characterization of a mutant of Staphylococcus aureus deficient in autolytic activity. A mutant of Staphylococcus aureus H (RUS3) uas isolated after mutagenesis with N-methyl-N'-nitro-N-nitrosoguanidine. The rate of autolysis of whole cells and isolated cell walls of RUS3 was less than 10% of the parent strain. In addition, the ability of the crude soluble enzyme isolated from RUS3 to degrade cell walls was negligible compared with the parent strain. The cell wall composition and the generation time of RUS3 were comparable to the parent strain. Unlike S. aureus H, RUS3 grew in clumps and did not undergo cell wall turnover. Both strains exhibited identical kinetics of killing by penicillin G. This may indicate that autolytic enzymes play a role in cell wall turnover and cell separation, but in S. aureus most of the autolytic activity is unrelated to the lethal effect of cell wall antibiotics.


Requirement for pantothenate for filament formation by Erwinia carotovora. Pantothenate is required for the formation of filaments by Erwinia carotovora. This has been demonstrated for the following division-inhibiting agents: D-serine, D-cycloserine, penicillin, vancomycin, fluoride ion, and ultraviolet light. D-Serine inhibits pantothenate synthesis in an ammonia-glucose or an ammonia-pyruvate medium; therefore, it is necessary to add pantothenate to obtain filament formation in these media, using D-serine as the division-inhibiting agent. Under conditions in which pantothenate synthesis is not inhibited by the agent producing filaments, the need for it for filamentation was shown by the use of salicylate, an inhibitor of endogenous pantothenate synthesis. Evidence is presented that the production of filaments is a specific response to pantothenate, rather than a nonspecific growth stimulation.


Metabolism of resorcinylic compounds by bacteria: orcinol pathway in Pseudomonas putida. Enrichment cultures yielded two strains of Pseudomonas putida capable of growth with orcinol (3,5-dihydroxytoluene) as the sole source of carbon. Experiments with cell suspensions and cell extracts indicate that orcinol is metabolized by hydroxylation of the benzene ring followed successively by ring cleavage and hydrolyses to give 2 mol of acetate and 1 mol of pyruvate per mol of orcinol as shown: orcinol leads to 2,3,5-trihydroxytoluene leads to 2,4,6-trioxoheptanoate leads to acetate + acetylpyruvate leads to acetate + pyruvate. Evidence for this pathway is based on: (i) high respiratory activities of orcinol-grown cells towards 2,3,5-trihydroxytoluene; (ii) transient accumulation of a quinone, probably 2-hydroxy-6-methyl-1,4-benzoquinone, during grouth with orcinol; (iii) formation of pyruvate and acetate from orcinol, 2,3,5-trihydroxytoluene, and acetylpyruvate catalyzed by extracts of orcinol, but not by succinate-grown cells; (iv) characterization of the product of oxidation of 3-methylcatechol (an analogue of 2,3,5-trihydroxytoluene) showing that oxygenative cleavage occurs between carbons bearing methyl and hydroxyl substituents; (v) transient appearance of a compound having spectral properties similar to those of acetylpyruvate during 2,3,5-trihydroxytoluene oxidation by extracts of orcinol-grown cells. Orcinol hydroxylase exhibits catalytic activity when resorcinol or m-cresol is substituted for orcinol; hydroxyquinol and 3-methylcatechol are substrates for the ring cleavage enzyme 2,3,5-trihydroxytoluene-1,2-oxygenase. The enzymes of this pathway are induced by growth with orcinol but not with glucose or succinate.


Beta-Adrenergic receptor interactions. Characterization of iodohydroxybenzylpindolol as a specific ligand. Hydroxybenzylpindolol (HYP) is a specific and highly potent beta-adrenergic antagonist. Monoiodination of HYP produces an equally high affinity inhibitor of binding to and activation of the beta receptor-coupled adenylate cyclase in turkey erythrocyte membranes. Monoiodohydroxybenzylpindolol was isolated by high pressure liquid chromatography. Mass spectroscopy showed that the iodine was contained in the phenolic moiety of the molecule. 125I-HYP was purified in tracer amounts by ion exchange chromatography; specific activities were achieved (1500 to 2000 Ci/mmol) approaching theoretical for 1 mol of iodine/mol of HYP. 125I-HYP interacts with a single stereospecific site with affinity of 4 to 5 X 10(10) M-1 by Scatchard analysis. Maximal binding capacity was 0.2 to 0.3 pmol/mg of membrane protein. If recovery of receptor were complete, this would correspond to 400 to 600 receptor sites per cell. Kinetic analyses of the on and off reactions gave a kinetically derived KA in good agreement with that derived from thermodynamic methods both at 20 degrees and 37 degrees. No evidence is found in these experiments for cooperative interaction of ligands with the receptor system. Iodohydroxybenzylpindolol thus represents a high affinity, high specific activity ligand of established chemical structure which should prove useful in studying the interaction of other blockers and agonists with the beta-adrenergic receptor in this and other biological systems.