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Biomedical subjects

J Young

Publications and source records attributed to J Young.

At least 433 records · Page 24Linked to original sources
PubMed1987

Urinary and hematologic indexes of hypohydration.

As part of a large-scale field feeding system test we were able to collect and study hundreds of aliquots of overnight urine samples obtained immediately prior to a fasting blood sample on days 1, 20, and 44 of the field test. The large number of experimental samples (greater than 650) and concomitant collection of blood and urine aliquots along with data on body weights gave us the opportunity to assess and quantitate the sensitivity of commonly used criteria of hypohydration. Urine aliquots for all test days were initially categorized by specific gravity (SG) greater than or equal to 1.03 (n = 124) or less than 1.03 (n = 540). Creatinine levels were elevated (P less than 0.001) in the concentrated urine samples, but a decreased trend in sodium-to-potassium ratios in these samples failed to achieve statistical significance (P greater than 0.05). However, when individuals with high SG urine were subclassified by a criterion of weight loss greater than 3% from original body weight, then creatinine concentrations were elevated (P = 0.05), whereas sodium-to-potassium ratios were decreased (P = 0.05) when subjects also with high SG but weight loss less than 3% were compared. Because of the moderate altitude (2,000 m) of the field site and the time of sojourn (44 days), there occurred a slight, but significant (P less than 0.001), erythropoietic response. Hematocrit and serum osmolality were not significantly different when examined by the criteria of high or low SG urine and weight loss greater than or less than 3% original body weight.(ABSTRACT TRUNCATED AT 250 WORDS)

Blood Urea Nitrogen↗
PubMed1987

Steam sterilization trends in the U.S.A.

Steam sterilization practices, standards, and products in the United States are changing as the U.S. health care system continues to undergo dramatic restructuring. The causes of this restructuring are hospital consolidations, implementation of diagnostic-related-group reimbursement, cost-containment programs, and increasing acceptance of disposable packs.

Central Supply, Hospital↗
PubMed1986

Isolation from chicken antrum, and primary amino acid sequence of a novel 36-residue peptide of the gastrin/CCK family.

A peptide that cross-reacted with C-terminal gastrin/CCK antisera was isolated from chicken antral extracts by a combination of gel filtration and reversed-phase HPLC. The sequence was: Phe-Leu-Pro-His- Val-Phe-Ala-Glu-Leu-Ser-Asp-Arg-Lys-Gly-Phe-Val-Gln-Gly-Asn-Gly-Ala- Val-Glu-Ala-Leu-His-Asp-His-Phe-Tyr-Pro-Asp-Trp-Met-Asp-Phe(NH2). Aside from the C-terminal tetrapeptide and the Tyr residue, the molecule does not resemble other known forms of gastrin or CCK. The peptide was a potent stimulus of avian gastric acid but not pancreatic secretion. The results have important implications for the structure-activity and evolutionary relationships of the gastrin/CCK family.

Amino Acid Sequence↗
PubMed1986

Isolation, structure and properties of the C-terminal flanking peptide of preprocholecystokinin from rat brain.

The C-terminal flanking peptide of preprocholecystokinin has been isolated from rat brain. Micro-sequence analysis revealed the primary structure: Ser-Ala-Glu-Asp-Tyr-Glu-Tyr-Pro-Ser. Arylsulphatase and mild acid hydrolysis suggested that both tyrosine residues are sulphated. The peptide was not active in bioassay systems that respond to CCK8; the significance of the conserved tripeptide Ser-Ala-Glu is discussed.

Amino Acid Sequence↗
PubMed1986

Gene clusters and the evolution of the major histocompatibility system.

Gene clusters containing one or more sets of duplicated genes with related functions are probably the basic genetic functional units. The major histocompatibility systems, such as HLA and H2, are among the most complex gene clusters so far known and studied, and illustrate many of the features of their structure and evolution. They cover about one thousandth of the mammalian genome and include two major sets of cell surface products with different but related functions in the control of immune interactions, as well as genes for complement components and 21-hydroxylase. Molecular analysis has revealed an extraordinary complexity at the genetic level, reflecting a very long and involved evolutionary history. A description of the organization of the HLA system, especially the HLA-D region, and its function and polymorphism forms the basis for considering the evolution of such complex gene clusters.

Amino Acid Sequence↗
PubMed1986

Effect of antibodies to recombinant and synthetic peptides on P. falciparum sporozoites in vitro.

Antibodies were raised in mice immunized with several recombinant and synthetic peptides of the circumsporozoite protein of Plasmodium falciparum. The antibodies were evaluated for protective activity in a human hepatocyte culture system. They exerted their protective effect against the parasite at three points: sporozoite attachment to the hepatocyte surface, entry, and subsequent intracellular development. Inhibition of attachment and entry were found to be related to the antibody titer against the authentic circumsporozoite protein on the sporozoite surface, especially when peptides were administered with alum or complete Freund's adjuvant. Even when invasion was not totally inhibited, the presence of abnormal trophozoites and a frequent inhibition of schizont development in long-term cultures suggested continued activity of antibodies at the intracellular level after sporozoite penetration had been completed.

Animals↗
PubMed1986

Oral pyridostigmine administration in rats: effects on thermoregulation, clinical chemistry, and performance in the heat.

We have recently reported that acute intraperitoneal administration of pyridostigmine bromide to rats resulted in significant decrements in physical performance in the heat, adverse thermoregulatory effects, and exacerbated elevations in several indices of heat/exercise injury. Since it will be consumed orally as a prophylaxis for organophosphate poisoning, pyridostigmine was dissolved in the drinking water of rats. Consumption of pyridostigmine for 7 days (n = 34, 6.6 mg/day) resulted in a 23% (p less than 0.001) reduction of circulating cholinesterase when compared with a control group (n = 31) while ingestion for 14 days (n = 35, 8.9 mg/day) elicited a 39% (p less than 0.001) inhibition of circulating cholinesterase when compared to a second control group (n = 33). Water and food consumption, rate of weight gain, and overt behavior were unaffected by pyridostigmine consumption. When approximately half the animals in each group were exercised (9.14 m/min) in the heat (35 degrees C) to hyperthermic exhaustion (Tre = 42.5-43 degrees C, rats unable to right themselves), pyridostigmine consumption for 14 days effected a significantly (p less than 0.05) increased rate of weight loss, but no further effects on thermoregulation or performance were noted. Several minor increments were observed in clinical indices of heat/exercise injury in rats consuming pyridostigmine for 14 days. These data indicate that oral dosages of pyridostigmine can probably be titrated to levels of cholinesterase inhibition which are efficacious in prophylaxis against organophosphate toxicity without significant effects on selected physiologic and metabolic processes.

Administration, Oral↗
PubMed1986

Isolation and partial sequence of elasmobranch VIP.

We have used a combination of gel filtration, ion exchange chromatography and reversed-phase HPLC to isolate and characterize a VIP-related peptide from the gut of the elasmobranch Scyliorhinus canicula. The N-terminal decapeptide of the Scyliorhinus material was identical with that of porcine VIP. However, Scyliorhinus VIP did not cross react with antisera specific for the C-terminus of porcine VIP. Like porcine VIP, Scyliorhinus VIP was a potent stimulant of exocrine pancreatic secretion in the turkey, but the response to Scyliorhinus VIP had a shorter duration. VIP from a second elasmobranch, Squalus acanthius was partially purified, and had biological and immunochemical properties similar to those of Scyliorhinus VIP. The results indicate that elasmobranch VIP is identical to porcine VIP at its N-terminus, but differs at the C-terminus. These structural differences may influence the rate of metabolism of the peptide.

Amino Acid Sequence↗
PubMed1986

Clinical trial comparing bacitracin with Strep-A-Chek for accuracy and turnaround time in the presumptive identification of Streptococcus pyogenes.

In a clinical trial, Strep-A-Chek (a 10-min chromogenic test) was compared with the bacitracin disk susceptibility test for accuracy and turnaround time in the presumptive identification of Streptococcus pyogenes. Among 461 isolates of beta-hemolytic streptococci (344 throat isolates and 117 isolates from other sites), 303 group A S. pyogenes isolates were found. The sensitivities of the Strep-A-Chek and bacitracin tests were high (96.4 and 100%, respectively), but the bacitracin test had a lower specificity (84.2%) than the Strep-A-Chek test (98.7%). The predictive values for positive and negative test results were 99.3 and 93.4%, respectively, for Strep-A-Chek and 92.4 and 100%, respectively, for bacitracin. Strep-A-Chek correctly identified all isolates upon repeat testing. All bacitracin tests were performed on subcultures of isolates from the primary plate. Strep-A-Chek testing was performed on colonies from the primary plate when isolated colonies were available. This shortened the turnaround time for Strep-A-Chek compared with bacitracin by at least 24 h on nearly one-half (45%) of the isolates. A peripheral finding of this study was that sulfamethoxazole-trimethoprim blood agar offered no advantage over conventional blood agar with regard to the number of false-positive bacitracin tests obtained from each medium.

Bacitracin↗
PubMed1986

Comparative effects of seven antidepressant regimes on appetite, weight and carbohydrate preference.

Appetite, weight, and preference for carbohydrate-containing food were followed in patients treated in double-blind trials of seven antidepressant regimes. Trimipramine and isocarboxazid combined had a significant effect in increasing appetite, carbohydrate preference, and weight; in patients who had lost appetite at presentation and were on this treatment, improvement in Hamilton score was linked to increase in weight--a finding not true of the other treatments.

Antidepressive Agents↗
PubMed1986

Cumulative incidence rates for Hodgkin's disease and other hematologic malignancies, with special reference to age-related carcinogenesis.

The cumulative incidence rate throughout the life span was analyzed for 4,865 Hodgkin's disease cases, in comparison with 16,015 malignant lymphomas (ML), 1,694 acute lymphocytic leukemias (ALL), 3,967 acute myeloid leukemias (AML), 2,109 chronic myeloid leukemias (CML), and 4,752 chronic lymphoid leukemias (CLL) in US white reported in the SEER program during 1973-1981. A log-linear increase was observed in ML, AML, CML, and CLL throughout the life-span, but only in childhood in ALL. Hodgkin's disease showed a steep increase until age 20-24, and then the increase became much more gradual. The cumulative incidence rates for males and females were parallel for ML and leukemias, but diverged for Hodgkin's disease (the rate for females had a lower slope than that for males after age 20-24). This difference was mainly caused by a lower frequency in females of mixed cellularity and lymphocyte predominance subtypes. The incidence curve of Hodgkin's disease was consistent with the two-stage model of carcinogenesis; it is likely that the proliferation of progenitor cells peaks at a young age and that the death rate of so-called intermediate cells is a primary influence during the subclinical stage. The cytogenesis of Hodgkin's disease and the histologic variation with special reference to the T-zone histiocytes suggest that a strong host defense mechanism against neoplastic change is involved, rather than different etiologic influences.

Adolescent↗
PubMed1985

Effect of amines on erythropoietin-stimulated heme synthesis in fetal mouse liver cells.

Amines, diamines and polyamines inhibit the erythropoietin-stimulated incorporation of 59Fe into newly-synthesized heme by fetal mouse liver cells in short-term culture. As assessed by cellular retention of lactic dehydrogenase, most of these compounds affect the viability of the cells very little at concentrations that substantially inhibit heme synthesis. In the families of amines tested, compounds of chain length greater than five carbons are more effective inhibitors the longer the chain, and monoamines are more inhibitory than diamines. The naturally-occurring polyamines spermine and spermidine are among the most potent amine inhibitors tested.

Amines↗