Biomedical subjects
Publications and source records attributed to D Simon.
3 cases of retrocaval ureter (one of them presenting multiple urological anomalies) are discussed. In the presence of hydronephrosis, early operative reposition of the ureter is essential. Provided that the condition is diagnosed before extreme renal deterioration, the surgical repair can salvage remaining renal function.
The hypotensive effect of arachidonic acid in the rabbit increases simultaneously with the fall of the plasmatic unesterified fatty acids (NEFA), after treatment with nicotinic acid or heparin. In the case of nicotinic acid sensitization, which occurs in 10 minutes, the fall of NEFA occurs immediately. The sensitization by heparin appears only after 40 minutes following the injection; during this latency, the NEFA are enhanced; after the fall of NEFA, the rabbit becomes more sensitive to arachidonic acid. Mechanisms of heparinic sensitization are discussed.
The enlarged parotid glands seen in both poor nutritional states and in women with amenorrhea have always been considered to be separate entities. Thirteen observations are reported of a syndrome consisting of dysorexia (or anorexia), swelling of the salivary glands (sialomegaly), and menstrual disturbances (hypomenorrhea or amenorrhea). This syndrome can be defined as a clinical entity combining the symptomatology of parotid enlargements due to poor nutrition and those caused by sex-hormone disorders. In the Dysorexia-Sialomegaly-Amenorrhea syndrome, the salivary gland swellings are due to poor nutrition and the amenorrhea, which is of the hypothalamic type, is also secondary to poor nutrition.
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Relationships between aggression and sexual behavior were examined in 6 cockroach species (genera Periplaneta and Blatta) in a descriptive manner. Aggressive encounters were classified according to intensity level. The behaviors themselves were scrutinized for differences according to varying contexts such as food and water deprivation and sexual situations. Sexual and species differences in aggressive behaviors were analyzed. Sexual encounters in cockroaches are considered as conflict situations in which many of the sexual behaviors of male male serve to neutralize aggressive behaviors of the female. Major adaptations include a male pheromene, tergal glands and defensive manoeuvering with body and legs.
As part of a study of sexual behavior in 6 species of closely related and often sympatric cockroaches, interspecific interactions among the various species were examined. To some degree males of nearly all species court females of a second species. Females almost always rejected these courtship attempts. Experimental evidence indicates that the volatile female sex pheromone of each species is attractive to males of most of the other species. Rejection of heterospecific males appears to be due to species specific male pheromones. These pheromones also appear to mediate the formation of homospecific clusters of courting males in time or space.
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The rRNA of the oncogenic bacterium Agrobacterium tumefaciens was extracted by several methods and analysed by polyacrylamide-gel electrophoresis. The large rRNA of this bacterium is degraded in vivo during the maturation of the ribosome. The influence of Mg2+ and denaturation on degradation of 23S RNA was studied. In pulse and chase experiments, we identified two precursors of the rRNA with mol.wts. of 1.04 x 10(6) and 0.70 x 10(6). From studies of the structure of the large rRNA, we propose that it could have arisen from a gene duplication. This structure is discussed in relation to a recent hypothesis involving such gene duplication as a means of origin of 23S rRNA.
The literature on clinical and experimental studies of sodium dipropylacetate (DPA), a branched chain carboxylic acid with a unique antiepileptic structure, is critically reviewed. The clinical antiepileptic properties are evaluated by seizure type. DPA appears to be most efficacious in the treatment of absence seizures. The literature also provides evidence for efficacy in the treatment of generalized tonic-clonic seizures and partial seizures with elementary symptomatology. The clinical pharmacology of DPA has not been thoroughly investigated. Simple, accurate, and reproducible gas-liquid chromatographic methods are available for determining the concentration of DPA in body tissues and fluids. The plasma half-life in humans is 8 to 15 hr. The most frequently observed adverse effects are gastrointestinal disturbances. In patients receiving additional antiepileptic drugs, potentially serious sedative effects have also been noted, which may be due to an interaction between DPA and concurrently administered medications.
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The relationship between coffee drinking and cancer of the lower urinary tract (LUT) was investigated by a case-control study of white women identified from hospitals in urban areas of Massachusetts and Rhode Island. Data on coffee drinking, tea drinking, use of coffee additives, and cigarette smoking were obtained by mail questionnaire. Information was available for 135 women with LUT cancer and 390 controls. For women who usually drank 1+ cups of coffee per day, the risk ratio of having LUT cancer was 2.1 (95 percent confidence limits, 1.1-4.3), compared to a risk of 1 for women who drank less or not at all. However, no dose-response relationship was demonstrated between LUT cancer and usual daily coffee consumption or "cup-years" of coffee drinking. The association of coffee with disease was no different, whether decaffeinated, nondecaffeinated, regular, or instant coffee had been drunk, or whether the coffee was brewed strong or weak. Use of nondairy creamers, saccharin, or cyclamates was not associated with increased risk of disease. The risk of LUT cancer for cigarette smokers relative to nonsmokers was 1.6 (1.0-2.4). The attendant dose-response relationship was statistically significant. The absence of a dose-response relationship between coffee drinking and LUT cancer suggested that the association observed was noncasual.
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