Combination adriamycin/misonidazole toxicity in V79 spheroids

The internal, hypoxic cells of V79 spheroids are preferentially killed by misonidazole, whereas adriamycin is preferentially toxic to the external cells due to diffusion limitations. Evaluation of combination treatments with misonidazole and adriamycin was therefore undertaken in an attempt to optimize and equalize cell killing throughout these spheroids. A fluorescence-activated cell sorter was used to select cells as a function of intracellular adriamycin or Hoechst-33342 fluorescence (and, therefore, as a function of location in the spheroid) for subsequent viability determinations. As expected, preferential toxicity of each agent was easily demonstrable, and with prolonged treatment times with both agents, greater uniformity of killing was achieved throughout the spheroid. Additionally, some suggestion of enhanced adriamycin toxicity to aerobic cells of spheroids chronically exposed to misonidazole was observed, analogous to the increased radiation sensitivity previously reported for similar exposure conditions. These results demonstrate that combinations of chemotherapeutic agents can be chosen to have preferential activity against different subpopulations of cells within V79 spheroids. Presumably, a better understanding of the factors contributing to drug resistance will lead to the application of similar principles for human cancer therapy.

Screening procedure for uric acid as indicator of infestation in spices

Uric acid levels in selected spice products were determined by using a glucose analyzer, modified and calibrated for uric acid. In the method, uricase is used to decompose the uric acid; the reaction is monitored with an oxygen-sensitive electrode. Uric acid levels correlated with infestation as determined by AOAC methods.

Bromocriptine suppresses ACTH secretion from human pituitary tumour cells in culture by a dopaminergic mechanism

Bromocriptine (0.13-13 microM) significantly inhibited ACTH secretion in a dose-dependent manner when added to cell cultures of a human corticotrophic adenoma for 24 h. Haloperidol (13 microM), but not serotonin (13 microM), blocked this inhibition but had no significant effect when added alone. In addition, dopamine (10 microM) reduced ACTH secretion during a 4-h incubation, whereas serotonin (0.01-10 microM) was ineffective. An ectopic ACTH secreting lung carcinoid was non-responsive to doses of bromocriptine up to 13 microM. These results demonstrate a direct suppressive action of bromocriptine on a human pituitary corticotrophic adenoma through dopaminergic rather than serotoninergic mechanisms.

Terbutaline sulfate in the prevention of recurrence of premature labor

Forty-six patients in premature labor were initially successfully treated with ethanol infusion. Twenty-three of these patients were then given prolonged oral terbutaline sulfate therapy until 38 weeks' gestation, and the remaining 23 patients were given placebo. The treated group gained significantly more time in gestation than the placebo group (P < .05), although the placebo group started with a higher Bishop score. In addition, idiopathic respiratory distress syndrome was seen significantly less often in the treated group. There was no perinatal mortality in either group.

Variations in herpes simplex virus isolated from human ganglia and a study of clonal variation in HSV-1

Growth of human sensory ganglia in culture has led to the reactivation of herpes simplex virus from over 50% of cases studied. Infected cell polypeptide and restriction enzyme analysis has led to the conclusion that each individual has one unique latent strain of HSV-1 that can be present in more than one ganglion in the body. Analysis of 91 isolates has shown that the long region of the genome is variable in terms of DNA restriction sites, DNA sequences, and in coding for the majority of variable polypeptides. The short region is stable with only polypeptides Vmw 21 and 22, restriction sites HindIII-(M-N) and BglII-(G-H) and the DNA sequence BamHI-1' having been found to vary. The insertion and deletion of small DNA sequences at specific locations allows individual reactivation events to be distinguished. Detection of information able to complement and produce ts+ virus on superinfection of otherwise negative ganglia with ts mutants, has led to the conclusion that ganglion cells may harbor herpes virus-related information that is only detectable by use of such genetic probes.

The use of epidemiologic data in the assessment of cancer risk

Epidemiologic data can be extremely important in arriving at quantitative estimates of human cancer risk, expressed either as (a) attributable risk, or (b) relative risk. While case-control studies have a low cost/benefit ratio, cohort studies are more likely to yield data relating risk to amount of exposure, and to allow precise calculation of risk. However, cohort studies are long, expensive, and difficult to administer. Attrition and resultant unrepresentative composition can be major problems. Cohorts should be followed to extinction to permit accurate calculation of risk, which must take into account prolonged latency periods, competing risks, and the likelihood of increasing risk with time (or age). In view of certain limitations in epidemiologic and virologic methods, critical re-evaluation of the viral and oncogene theories are called for. The use of animal data for assessing human cancer risk requires further investigation of the assumptions and facts supporting two kinds of extrapolation: That from high to low dose carcinogen exposure, and cross-species extrapolation (i.e., from experimental animals to man). Large pieces of these two approaches rest on testable hypotheses which deserve further attention.

Detection by complementation of defective or uninducible (herpes simplex type 1) virus genomes latent in human ganglia

Reconstruction experiments have shown that temperature-sensitive (ts) mutants of herpes simplex virus type 1 (HSV-1)(Glasgow strain 17) grow, complement, and recombine with similar efficiency in human nerve ganglion cells, human brain cells, normal human fibroblasts (WI38), and baby hamster kidney (BHK) 21/C13 hamster cells. Cultures of human trigeminal, superior cervical, and vagus ganglia that had failed to release herpes simplex virus spontaneously were superinfected with a range of ts mutants of HSV-1 and incubated at both permissive (31 degrees C) and nonpermissive (38.5 degrees C) temperatures. Progeny virus was assayed at both temperatures to determine if complementation of or recombination with the input genomes had occurred. The results showed that the ganglia from 8 of 14 individuals, which had been consistently negative for spontaneous release of virus, contained information that could be detected or rescued following superinfection with ts mutants of herpes simplex virus. In two additional cases, positive results were obtained after the superinfection of negative ganglia explants, but in each of these herpes simplex virus had previously been spontaneously released from one of six ganglia explanted.

The polypeptide and the DNA restriction enzyme profiles of spontaneous isolates of herpes simplex virus type 1 from explants of human trigeminal, superior cervical and vagus ganglia

Analysis of the infected cell polypeptides and the DNA restriction profiles of 31 HSV-1 isolates from the trigeminal, superior cervical and vagus ganglia from 17 individuals (12 U.S.A., 2 Japanese, 3 Norwegian) could be classified as 15 different virus strains. With the exception of the three Norwegian isolates which gave identical profiles, virus isolates from the ganglia of different individuals could all be distinguished from one another. In contrast virus isolates from the trigeminal, superior cervical and vagus ganglia of the same individual, or virus isolates from the left and right ganglia of the same individual or multiple isolates from different explants of a single ganglion were indistinguishable. In conclusion, a single virus strain infects each individual initially and virus descended from this event subsequently infects and becomes latent in different cells of the same ganglion as well as in different ganglia.

Some fundamental aspects of epidemiology: a guide for laboratory scientists

Epidemiologic methods used to study human diseases are often unfamiliar to the laboratory scientist. This paper outlines the standard method by which epidemiologic studies are classified, explains the methodologic strengths and weaknesses of different kinds of studies, and notes the kinds of inferences that can be drawn from each. Surveys on populations are treated first, followed by sample surveys. Prospective (follow-up) studies, in which groups of subjects are followed in time, are a basic epidemiologic method. Alternatives to these studies that do not require similar time commitments but may allow similar inferences are record studies. Retrospective, or case-control studies, are often the only feasible method for studying rare diseases. However, diseases with long latency periods and problems in control selection can make these studies difficult to analyze and interpret.

Virology and histopathology of the trigeminal ganglia of Americans and Japanese

Herpes simplex virus in the trigeminal ganglia of humans was studied in Philadelphia, Pennsylvania, United States of America, and in Kyoto, Japan. The prevalence of recurrent herpes labialis and of clinically latent herpes simplex virus within trigeminal ganglia was determined in inhabitants of the two cities. In addition, a comparison was made of the prevalence of mononuclear cell infiltration in the trigeminal ganglia of Americans and Japanese. Recurrent herpes labialis was found to be significantly less common in the Japanese city than in the American city. Herpes simplex virus was rescued less commonly from the trigeminal ganglia of cadavers in Japan than in America. The difference was significant. The frequency of mononuclear cell infiltration in the trigeminal ganglia of Americans and Japanese is not significantly different. These observations, as well as previously reported serological studies, suggest that despite the ubiquitous nature of herpes simplex virus in America and Japan, the Japanese have less clinically overt disease caused by this virus.

Variations in the resting oxygen consumption of small babies

Over 200 measurements of the resting rate of oxygen consumption using an open-circuit method were made on 15 small babies nursed in their usual clinical setting during the first month of life. There were striking and persistent variations between babies that could not be explained by postnatal age, relationship to feed, sleep, or time of day. It was not possible from clinical examination to predict which babies had the higher or lower metabolic rates, except that babies who were light-for-dates generally had higher values. Because of these variations the appropriate thermal temperature for small babies cannot be predicted from average values adjusted for body weight and postnatal age alone.

Prostatic cancer: mortality and incidence rates by race and social class

Among the most striking epidemiologic characteristics of prostatic cancer in the United States is the sizeable excess in rates for the disease among blacks as compared with whites. This study attempted to determine whether the higher black rates might be explained by controlling for social class, using mortality data from Alameda County for the pericensal period 1968--1972 (n = 400), and the population-based series of cases for Alameda County included in the Third National Cancer Survey, 1969--1971 (n = 750). Reviewed first are previous studies addressed to the relationship of prostatic cancer and socioeconomic status (SES), most of which have been confined to whites. In the present study, each death or case was assigned to a socioeconomic class based on census tract of residence and rates by race and social class determined. Comparison of age-specific mortality and incidence rates by SES reveals no gradient for prostatic cancer in either whites or blacks.

Isolation of Herpes simplex virus from human trigeminal ganglia, including ganglia from one patient with multiple sclerosis

Herpes-simplex virus (H.S.V.) was isolated from 18 of 39 trigeminal ganglia (T.G.) obtained within 12 h of death. The virus was isolated from ten persons who had died of trauma, from one case of lymphoma, and from one case of multiple sclerosis. In the cadaver with histologically confirmed multiple sclerosis, large bilateral areas of demyelination were present near the points of entry of the nerve root, and the possibility that H.S.V. migration to the root entry zone caused demyelination cannot be excluded.