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Biomedical subjects

P Snyder

Publications and source records attributed to P Snyder.

47 records · Page 3Linked to original sources
PubMed1981

Gonadotropin release after administration of GnRH in depressed patients and healthy volunteers.

Considerable attention has been paid to studies of hormonal response abnormalities in depressed patients, and functional changes have been demonstrated in a number of neuroendocrine axes. The findings from the present study extend the results of previous investigations but demonstrate a functionally intact HPG axis in depressed patients. A number of statements can be made concerning the gonadotropin-releasing hormone (GnRH) strategy: (1) Previous studies utilizing GnRH challenge have been limited in number and poorly controlled. (2) We chose to utilize our normative data because standard gonadotropin response ranges to GnRH have not previously been established in studies with depressed patients. Moreover, hormonal responses may be affected by age, sex, menstrual status, dose, and method and rate of GnRH administration. The assessment of the hormonal responses to GnRH in depressed patients and healthy controls studied under identical conditions provides the most accurate basis for comparison. (3) The incidence of abnormal LH and FSH release in depressed subjects was similar to controls, in contrast to response abnormalities found with other neuroendocrine axes. (4) Alterations in gonadotropin were limited to FSH, were sporadic, and did not differ significantly from controls. This finding is of interest and suggests that neuroendocrine alterations in depression do not necessarily affect all neuroendocrine axes.

Adult↗
PubMed1980

Evidence for the common origin of viral and cellular sequences involved in sarcomagenic transformation.

The src genes of six different strains of avian sarcoma virus (ASV) were compared with those of a series of newly isolated sarcoma viruses, termed "recovery avian sarcoma viruses" (rASV's). The rASV's were isolated recently from chicken and quail tumors induced by transformation-defective (td) deletion mutants of Schmidt-Ruppin Rous sarcoma virus. The RNase T1-resistant oligonucleotide maps were constructed for the RNA genomes of different strains of ASV and td mutants. The src-specific sequences, characterized by RNase T1-resistant oligonucleotides ranging from 9 to 19 nucleotides long, were defined as those mapping between approximately 600 and 2,800 nucleotides from the 3' polyadenylate end of individual sarcoma viral RNAs, and missing in the corresponding td viral RNAs. Our results revealed that 12 src-specific oligonucleotides were highly conserved among several strains of ASV, including the rASV's, whereas certain strains of ASV were found to contain one to three characteristic src-specific oligonucleotides. We previously presented evidence supporting the idea that most of the src-specific sequences present in rASV RNAs are derived from cellular genetic information. Our present data indicate that the src genes of rASV's are closely related to other known ASVs. We conclude that the src genes of different strains of ASV and the cellular sarc sequences are of common origin, although some divergence has occurred among different viral src genes and related cellular sequences.

Alpharetrovirus↗
PubMed1979

Effects of maternal drinking on neonate state regulation.

Sleep-awake state distribution during inter-feed intervals over a 24-hour period on the third day of life was investigated by means of a continuous non-intrusive bassinet sleep monitor. 31 infants were studied: 14 born to mothers who drank heavily throughout pregnancy (group A), eight whose mothers modified their heavy drinking (group B) and nine whose mothers never were heavy drinkers (group C). Over the 24-hour period, group A infants slept less than those in group B. In comparison with group C, group A infants had a larger proportion of quiet sleep episodes interrupted by awake or unclassified epochs, and were more restless, with more frequent major body movements. These pilot observations suggest that heavy maternal consumption of alcohol, when continued throughout pregnancy, is associated with a disturbance of sleep-awake state distribution. Successful therapy of heavy drinking during pregnancy may improve the physiological competence of the newborn to regulate sleep-awake states and facilitate interaction between mother and infant.

Adolescent↗
PubMedDate not supplied

Impact of fat reduction on micronutrient density of children's diets: the CATCH Study.

BACKGROUND: The purpose of this study was to examine the impact of fat reduction on vitamin and mineral density in the diets of groups of children who participated in the CATCH school-based intervention study for 2 1/2 years. METHODS: Twenty-four-hour dietary recalls were collected on 1,182 children residing in four states and with diverse ethnic backgrounds, at baseline when they were in third grade and again at follow-up when they were in fifth grade. RESULTS: With a 2.4% reduction in total fat intake from baseline levels in the intervention group, mean changes in vitamin and mineral intakes per 1,000 kcal of this group were small yet significant compared with the control group. As mean fat intake decreased, the nutrient density of most vitamins and minerals increased; the sole exceptions were vitamin E and sodium. Mean intake of all vitamins and minerals studied exceeded 2/3 of the RDA at both baseline and follow- up for both the intervention and the control groups. No significant differences were noted between treatment groups for the percentages of children meeting 2/3 or more of the RDA at both baseline and follow-up periods. CONCLUSIONS: CATCH was successful in maintaining mean vitamin and mineral intakes of intervention group children when total dietary fat was reduced.

Adolescent↗
PubMedDate not supplied

Use of triple-lumen subclavian catheters for administration of total parenteral nutrition.

This study evaluated the safety of triple vs single-lumen catheters in intravenous nutrition. Patients who were judged likely to benefit from a triple-lumen catheter were randomized to receive either a single-lumen catheter, with additional peripheral or central venous access as needed, or a triple-lumen catheter. All patients were at increased risk of catheter-related infection because of one or more of the following conditions: > 60 years of age, breakdown of skin integrity, severe underlying illness, diagnosis of acute pancreatitis, recent head or neck surgery, or presence of a preexisting infection. Patients were excluded who had neutropenia, were immunosuppressed, had body burns > 40%, or had contaminated wounds in the subclavicular area. Of 204 patients entered between June 1989 and November 1991, 177 completed the required > or = 7 days of therapy. Seventy-eight of these patients were randomized to a single-lumen catheter and 99 to a triple-lumen catheter. Catheters were inserted and maintained by the Nutrition Support Team. Dressings were monitored daily and changed weekly using a bio-occlusive dressing. When parameters were met for a possible septic episode, simultaneous peripheral and central catheter blood cultures were obtained using the Isolator method. Catheter-related sepsis was considered present if the colony count from a central catheter lumen was > or = 5 times that of the peripheral blood. The incidence of catheter-related sepsis for single-lumen catheters was 2.6% (2 of 78) compared with 13.1% for triple-lumen catheters (13 of 99) (p < .01). No correlation was found with the number of insertion attempts, catheter days, or patient's age.(ABSTRACT TRUNCATED AT 250 WORDS)

Bacterial Infections↗