Search PubMed⌕ Search

Biomedical subjects

J Taylor

Publications and source records attributed to J Taylor.

At least 595 records · Page 33Linked to original sources
PubMed1985

Metropolitan forensic anthropology team (MFAT) case studies in identification: 3. Identification of John J. Sullivan, the missing journalist.

Skeletal remains removed from an unmarked grave in El Salvador were intensively studied by a team of forensic science experts. Even though the skull, teeth, and several major bones were missing, a positive identification was made of the missing journalist. This was contrary to reports submitted to the State Department by Salvadorian officials. All of the methods used in this investigation, which includes a new method for simultaneously assessing sex and race by discriminant function analysis that was tested by application, are fully described. The international background of this case and information regarding the cause of death is discussed.

Adult↗
PubMed1984

Evidence that the folate-requiring enzymes of de novo purine biosynthesis are encoded by individual mRNAs.

Isolation of the mRNAs encoding for the three folate-requiring enzymes involved in de novo purine biosynthesis followed by their in vitro translation resulted in three separate proteins electrophoretically identical with those previously isolated. The three enzymes are glycinamide ribonucleotide transformylase, 5-aminoimidazole-4-carboxamide ribonucleotide transformylase, and 5,10-methenyl-, 5,10-methylene-, and 10-formyltetrahydrofolate synthetase. Thus these enzymes do not appear to be derived from large multifunctional proteins that are then subject to proteolysis in vivo or during in vitro purification. The levels of these enzymatic activities were increased by approximately 2-fold after raising the concentration of protein in the chicken's diet. The observed response is similar to that noted for glutamine phosphoribosylpyrophosphate amidotransferase, the presumed rate-limiting enzymatic activity for this pathway. For 5-amino-imidazole-4-carboxamide ribonucleotide transformylase and the trifunctional synthetase but not glycinamide ribonucleotide transformylase the increase in enzymatic activity correlates with higher mRNA levels.

Acyltransferases↗
PubMed1984

Long-term outcome of episodes of major depression. Clinical and public health significance.

Twenty-one percent (20/97) of patients with an episode of major depressive disorder and no history of chronic minor depression who sought treatment at five university medical centers had not recovered after two years of prospective follow-up. The rate of recovery was highest in the three months after entry into the study, with a notable decrease in rate after one year. Most patients who did not recover had severe depressive symptoms throughout the two years of follow-up. Long duration of episode before entry into the study, inpatient hospitalization status at entry, intact marriage, low family income, admitting research center, and a history of nonaffective psychiatric disorders (including alcoholism) predicted a chronic course. The implications of these findings for clinicians, researchers, and public health planners are discussed.

Adult↗
PubMed1984

Dependence of gluconeogenesis, urea synthesis, and energy metabolism of hepatocytes on intracellular pH.

The relationship of intracellular pH to extracellular pH has been measured in suspensions of isolated hepatocytes at 25 degrees C. The internal pH was found to be a linear function of external pH and it changed by 0.45 pH unit per 1.0 unit change in external pH. The internal [H+] was equal to the external [H+] at approximately pH 7.1. Gluconeogenesis, urea synthesis, and oxidative phosphorylation showed different dependencies on the intracellular pH. Gluconeogenesis was the most sensitive to changes in [H+] and it declined by 80% when the intracellular pH decreased from 7.1 to 6.9. Urea synthesis was less pH-dependent, decreasing by about 30% for the same change in the intracellular [H+] whereas respiratory rate showed very little dependence on pH at this temperature. Intracellular [ATP]/[ADP] decreased linearly from 8.5 to 1.5 as the intracellular pH increased from 6.8 to 7.6, while intracellular [Pi] was essentially constant at 3.2 nmol/mg of cells, wet weight. Cytochrome c became more reduced with increasing intracellular pH, from less than 10% at pH 6.8 to 35% at pH 7.7. The calculated free energy of hydrolysis of ATP was nearly independent of pH as was the free energy of electron transfer from the intramitochondrial NAD couple (calculated from the [acetoacetate]/[3-OH-butyrate] ratio) to cytochrome c.

Animals↗
PubMed1984

Evaluation of comprehensive rehabilitation services for elderly homebound patients with arthritis and orthopedic disability.

Fifty-seven elderly homebound patients with arthritis and orthopedic disabilities were randomized to a goal-oriented outreach rehabilitation program or to usual treatment. Although 64% of patient goals were met, there were no overall significant differences in functional scores, institutionalization, or contentment between treatment and control periods. Twenty-three patients had maintained clinical improvement at the end of the study and some patients were dramatically improved with simple measures. The program's marginal costs were modest and consisted primarily of expenses associated with therapist's visits. The total costs of assistive devices and home modifications amounted to $1,902. Twenty-five percent of the homebound population could benefit from such services but the actual number who would partake is small.

Aged↗
PubMed1984

Costs and outcomes in rheumatoid arthritis and osteoarthritis.

A prospective descriptive study was done on the direct and indirect costs to ambulatory patients with rheumatoid arthritis and osteoarthritis, stratified at study entry by level of function. Measures of health status over a 1-year period were taken. On a yearly basis, in 1979 dollars, patients spent an average of $147 for arthritis medications, aids, and devices, and $207 for outpatient visits. A small number were hospitalized and incurred an average charge of $245, and an additional $84 for physician fees. In addition to direct monetary costs, patients averaged 6.8 days of restricted activity costs, patients averaged 6.8 days of restricted activity per month, in some cases so severe as to confine patients to bed for an average of 1.3 days per month. Among students and working patients, 2.5 work-days per month were lost due to arthritis, and 30% reported that they were unemployed or retired because of impaired health. Functional capacity and specific diagnosis on entry to the study were the most important determinants of arthritis-related expenditures. Both direct and indirect costs varied considerably from the observed average. Twenty percent of patients incurred no costs for arthritis-related purchases, 42+ had no costs for outpatient visits, and 93% had no inpatient costs. Yet for some patients, the financial burden was very high.

Arthritis, Rheumatoid↗
PubMed1984

Significance of the endogenous digoxin-like substance in infants and mothers.

Digoxin serum concentrations were measured by a routine radioimmunoassay in 30 neonates not receiving digoxin; nonetheless, digoxin levels were between 0.17 nM and 1.64nM (means = 0.64nM +/- 0.27 nM). There was a negative correlation between gestational age and concentration of an endogenous digoxin-like substance (EDLS). Neonates less than or equal to 32 wk gestational age had higher levels of EDLS than neonates greater than 32 wk old. EDLS concentrations were compared in 22 mothers and their 24 offspring and were higher in all newborn infants (0.34nM +/- 0.09nM and 0.15nM +/- 0.08nM). EDLS was shown to inhibit Na+-K+-adenosinetriphosphatase activity by measurement of 86Rb uptake in erythrocytes exposed to sera samples from 30 infants in the study. EDLS levels greater than 0.6 ng/ml were associated with lesser 86Rb uptake. Simulation kinetics suggest that the presence of 0.6nM EDLS would lengthen the digoxin t1/2 by 64%, reduce the volume of distribution by 23%, and lower clearance by 53% if the peak "true" digoxin level were 2 ng/ml. EDLS concentrations of 1.5 ng/ml would increase the t1/2 by 207% while reducing the volume of distribution by 43% and clearance by 81%. These considerations cast serious doubts on the validity of currently accepted digoxin kinetics and dosing in preterm infants.

Birth Weight↗
PubMed1984

Characterization of Nugget virus, a serotype of the Kemerovo group of orbiviruses.

The genome of Nugget virus, a serotype of the Kemerovo group of orbiviruses, consists of 10 segments of double-stranded RNA. The properties of the virus are consistent with its classification as an orbivirus , but the unusual patterns of separation of viral RNA and polypeptides compared with that reported for most other orbiviruses suggests the possibility of heterogeneity within the genus Orbivirus .

Electrophoresis, Polyacrylamide Gel↗
PubMed1984

Intracellular pH of perfused single frog skin: combined 19F- and 31P-NMR analysis.

Intracellular pH (pHc) has been determined in frog skin by applying two different methods of pH measurement, 19F and 31P nuclear magnetic resonance (NMR) analysis, to the same tissues. Results from both NMR approaches confirm an observation by Lin, Shporer, and Civan [Am. J. Physiol. 248 (Cell Physiol. 17): 1985] that acidification of the extracellular medium reverses the sign of the pH gradient present under baseline conditions. The fluorinated probe, alpha-(difluoromethyl)-alanine methyl ester, was introduced into the epithelial cells by preincubating skins for 4.7-10.4 h at room temperature in Ringer solutions containing 1 mM ester. The free amino acid was subsequently released by intracellular esterase activity, thus providing a high enough probe concentration for NMR analysis to be practicable. From measurements of short-circuit current and transepithelial resistance under base-line and experimental conditions and the appearance of phosphocreatine (PCr) in the 31P spectrum of preloaded tissues, the fluorinated probe appears to be nontoxic to frog skin. Measurement of the chemical shift of methylphosphonate relative to PCr permitted calculation of extracellular pH. Estimation of the intracellular pH was performed both by measurement of the chemical shift of inorganic phosphate (Pi) relative to PCr and by measurement of the central peak spacing of the 19F spectrum. From four direct comparisons of the two techniques in two experiments, the difference in the estimated pH was only 0.03 +/- 0.07 pH units, supporting the concept that 31P-NMR analysis is a valid method of measuring pH in this tissue.

Animals↗
PubMed1984

Phasic and tonic modulation of impulse rates in gamma-motoneurons during locomotion in premammillary cats.

To determine the role of gamma-motoneurons in the control of locomotion, we isolated single units from nerves to triceps surae muscles in the premammillary cat. The limb used for recording was largely denervated, except for the muscles of interest, and fixed in place, while the other three limbs walked on a treadmill. One type of gamma-motoneuron (13 units) had a high impulse rate at rest, which changed little on average during walking, but was deeply modulated with each step (phasically modulated gamma-motoneuron or gamma p). Another type (19 units) had a low impulse rate at rest, which increased greatly on average during walking, but was not highly modulated with each step (tonically modulated gamma-motoneuron or gamma t). Peak gamma p rates generally occurred after peak EMG, often near the peak of tension. In contrast, peak gamma t activity generally preceded peak electromyograms (EMG). No significant difference was observed in conduction velocities for the two types of units. At rest all gamma t units were excited by natural stimulation of the fur over a large part of the body surface, whereas 3 of 11 gamma p units were inhibited. During locomotion the same natural stimuli had no observable effect on either type of unit. By recording in continuity from fine branches of the lateral and medial gastrocnemius nerves and stimulating ventral root filaments in continuity, we identified dynamic and static gamma-motoneurons in terms of their effects on muscle spindle afferents. After cutting the nerve branch distally and other ventral root filaments supplying the muscle, the resting discharge of dynamic and static gamma-motoneurons was recorded and found to correspond to that of the gamma p and gamma t units, respectively. Other evidence is presented for a correspondence between phasically and tonically modulated units and dynamic and static gamma-motoneurons, contrary to some suggestions in the literature.

Action Potentials↗
PubMed1984

Premature rupture of membranes before fetal viability.

The outcome of 53 cases expectantly managed with premature rupture of membranes (PROM) before fetal viability (16 to 25 weeks) was retrospectively reviewed. Forty-one percent of patients developed amnionitis, four had prolonged hospital stays (longer than seven days), and one each had sepsis and pelvic thrombophlebitis. Twenty-two mothers (41%) had no complications. No serious long-term maternal sequelae were noted. Eighteen patients were delivered after 26 weeks, and there were 13 surviving neonates with birth weights ranging from 740 to 2170 g.

Abortion, Spontaneous↗
PubMed1984

Indication for interstitial brachytherapy in carcinoma of the uterine cervix.

More than 40 patients with gynecological, genitourinary, and gastrointestinal malignancies, both primary and recurrent but confined to the pelvis, were treated with interstitial irradiation over a four-year period. Interstitial irradiation was the choice of treatment for early carcinoma of the prostate, carcinoma of the anal canal less than T2, recurrent carcinoma of the uterine cervix, and carcinoma of the cervical stump. The authors' experience in treating recurrent carcinoma of the uterine cervix with interstitial irradiation is the basis for the indications for selecting the technique of interstitial irradiation presented.

Brachytherapy↗
PubMed1984

Primary hyperparathyroidism, pregnancy, and neonatal hypocalcemia.

Primary hyperparathyroidism in the mother during pregnancy is known to result in a high rate of fetal complications; spontaneous abortions, still births, and neonatal tetany occur in excessive incidence. To understand the pathophysiology of neonatal hypocalcemia that accompanies this disorder, transplacental calcium dynamics were studied in female sheep during the last trimester of pregnancy and in their fetal lambs after hysterotomy. Calcium ion was shown to move rapidly across the placenta. However, this organ blocked the passage of both parathyroid hormone and calcitonin from the maternal and to the fetal circulations. Our studies support the hypothesis that in primary hyperparathyroidism maternal hypercalcemia results in fetal hypercalcemia, which leads to suppression of fetal parathyroid gland function. In such a situation, neonatal hypocalcemia would occur after birth when maternal calcium flow is interrupted. Parathyroidectomy performed in the mother, especially during the second trimester of pregnancy when operation is safest, would break this cycle and permit normal serum calcium homeostasis in the fetus.

Animals↗