Biomedical subjects
Publications and source records attributed to N S Davis.
Malignant melanoma of the scrotum is the rarest of primary genitourinary melanomas, with only 3 cases reported previously. We present an additional case of this often aggressive malignancy. The pertinent literature is reviewed and the current management strategies are discussed.
Calcitonin was extracted from surgically-derived prostate tissue, and quantified using radioimmunoassay. Normal prostatic specimens contained 15.18 +/- 10.03 ng./gm. wet weight (mean +/- S.D., n = 20), with a range of 1.50 to 39.62 ng./gm. The result for the hyperplastic tissue samples (n = 20) averaged 0.63 +/- 0.39 ng./gm. with a range of 0.22 to 1.49 ng./gm. This difference was statistically significant (p less than .0001). Dilution profiles for the prostatic calcitonin and synthetic monomeric human calcitonin were congruent, suggesting that the two peptides are identical. A comparison of calcitonin levels and the number of immunohistochemically derived neuroendocrine cells in contiguous tissue sections showed an empiric correlation. The mean calcitonin level in normal human prostate tissue was found to exceed values previously reported for numerous other organs, with the exception of the thyroid gland, the principal source of circulating calcitonin. We propose that a subpopulation of neuroendocrine cells within the prostate gland produce calcitonin, as is the case in the gastrointestinal tract, lung, and other organs. Our findings also support the hypothesis that the calcitonin found in seminal fluid originates in the prostate. Putative roles for calcitonin in the genitourinary system are discussed.
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A case of primary seminal vesicle carcinoma is described and is discussed in the context of current knowledge regarding the clinicopathologic features of this rare neoplasm.
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The finding of significant numbers of endocrine-paracrine (EP) cells in the prostate glands of guinea pigs and man suggests that these cells may be important in the regulation or modulation of prostatic function. Serotonin is a biogenic amine common to most prostatic EP cells. In order to extend current knowledge relating to these cells, an assay was developed using high-performance liquid chromatography to quantitate serotonin and its metabolite 5-hydroxyindoleacetic acid (5-HIAA) in guinea pig and human prostatic tissue extracts. Levels of serotonin and 5-HIAA in the guinea pig whole-gland preparation were 105.4 +/- 70.6 ng/g and 48.4 +/- 95.7 ng/g, respectively. Normal human prostatic tissue contained 1423.9 +/- 750.8 ng/g serotonin and 66.7 +/- 92.8 ng/g 5-HIAA. Recoveries ranged between 60 and 100%. The detection limits were 24 pg/injection for serotonin and 12 pg/injection for 5-HIAA. This assay provides an expeditious, specific and highly sensitive method for the simultaneous determination of monoamines in guinea pig and human prostatic tissue.
Neuroendocrine (endocrine-paracrine, APUD) cells of the guinea pig prostatic complex (prostate and coagulating gland) were studied at three age points (9-day-old weanlings, 11 to 12 week mature pre-breeders, and retired breeders) using serotonin immunocytochemistry for detection and subsequent morphometric analysis. Prostatic complex serotonin levels were determined for the same age groups using high performance liquid chromatography with electrochemical detection. The numbers of neuroendocrine (NE) cells in the prostatic complex of retired breeders was 1.42 +/- 0.29 NE cells/mm gland length (mean +/- SEM) and was increased nearly 24-fold when compared with mature pre-breeders with 0.06 +/- 0.03 NE cells/mm gland length and nearly 16-fold when compared with the weanlings with 0.09 +/- 0.04 NE cells/mm gland length. The increase in cell number in the retired breeders versus each of the other age groups was highly significant (p less than 0.001). The increase in NE cells appeared to take place exclusively in the prostate, whereas the number of NE cells in the coagulating gland were few and not significantly different in the three age groups. The number of urethral NE cells also appeared similar in all three age groups. The number of prostatic epithelial cells/gland length increased with age. The number of NE cells/100 prostatic epithelial cells was examined in the three age groups and the increase in retired breeders over the other two groups was still highly significant (p less than 0.001). Serotonin levels, which were measured for the whole prostatic complex, indicated a nearly 6-fold increase with age: retired breeders had 97.72 +/- 21.26 ng/g of wet tissue (mean +/- SEM) whereas mature pre-breeders had 17.1 +/- 2.88 ng/g of wet tissue (p less than 0.01). Weanling serotonin levels were not detectable. This dramatic age-related increase in prostatic NE cells and serotonin content could reflect a compensation for a decreased effectiveness of NE cell hormones, a nonfunctional primary hyperplasia, a hyperplasia secondary to endogenous hormonal or involutional changes or exogenous factors. Whatever the mechanism, this increase in prostatic NE cells with age is of great interest since human prostatic carcinoma and benign nodular hyperplasia are both strongly correlated with advanced age. Prostatic NE cells may, therefore, directly or indirectly be in the pathogenesis and/or evolution of these important pathologic processes.
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To determine whether sleep problems commonly seen in pediatric practice, such as conflicts at bedtime and night waking, are associated with more pervasive disturbances in the child or family, two groups of healthy children were studied. Interview data from a pilot sample were examined to identify factors that might be important in sleep problems, and then the results were validated with data from the second sample. The two samples included 96 white children between 6 months and 4 years of age. In each group, approximately 30% had a sleep problem by the criteria that night waking involving parents or bedtime struggles occurred three or more nights a week for the month preceding the interview, accompanied by conflict or distress. Five experiences distinguished children with sleep problems from those without: an accident or illness in the family, unaccustomed absence of the mother during the day, maternal depressed mood(s), sleeping in the parental bed, and maternal attitude of ambivalence toward the child. These experiences correctly classified 100% of pilot and 83% of validation sample children as having a sleep problem or not. The similarity of findings in the two samples attests to the potential importance of sleep problems as an early childhood symptom. Bedtime conflicts and night waking seem to be quantifiable, easily ascertainable behavior patterns that could alert pediatric health professionals to the existence of more pervasive disturbances in child and family.
The prevalence and correlates of sleeping in the parental bed among healthy children between 6 months and 4 years of age are described. One hundred fifty children were enrolled in an interview study on the basis of "well-child" care appointments in representative pediatric facilities. The sample created was similar in demographic characteristics to census data for the Cleveland area. In this cross section of families in a large US city, cosleeping was a routine and recent practice in 35% of white and 70% of black families. Cosleeping in both racial groups was associated with approaches to sleep management at bedtime that emphasized parental involvement and body contact. Specifically, cosleeping children were significantly more likely to fall asleep out of bed and to have adult company and body contact at bedtime. Among white families only, cosleeping was associated with the older child, lower level of parental education, less professional training, increased family stress, a more ambivalent maternal attitude toward the child, and disruptive sleep problems in the child.
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Viability studies were conducted on microbial spores subjected to ultrahigh vacuum (UHV) in the 10(-9) to 10(-10) torr range. After 5 to 7 days in vacuum, they were exposed to ultraviolet (UV) or to gamma radiation either while still under vacuum or in the presence of dried air. Among the four test organisms subjected to UHV and ultraviolet radiation, Aspergillus niger was the most resistant; Bacillus megaterium, B. subtilis var. niger, and B. stearothermophilus were about equally less resistant. All four spores were more sensitive to ultraviolet radiation when UHV-dried than when desiccant-dried. Of the four test organisms subjected to UHV and gamma radiation, B. megaterium proved to be the most resistant; A. niger was the least resistant; and the remaining two organisms were of intermediate resistivity. All four organisms were less radiation resistant when UHV-dried than when irradiated in their normally hydrated state, and all showed an increased radiosensitivity after vacuum drying when oxygen was present. In addition, spores of B. subtilis var. niger and A. niger were less radiosensitive when UHV-dried and irradiated in vacuum than when "wet" and irradiated in air, whereas the reverse relationship was observed for the remaining two organisms. Based on the fact that microbial contaminants can be readily shielded from UV light by soils, metal particles, etc., and considering that the levels of ionizing radiations reported to be present in interstellar space are generally lower than those used in these experiments, the decrease in radioresistivity imparted by UHV drying is not of a sufficient magnitude to sterilize dependably portions of a spacecraft while on a mission.