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Biomedical subjects

J L Neal

Publications and source records attributed to J L Neal.

15 recordsLinked to original sources
PubMed1989

Effect of phosphonoformic acid, dietary phosphate and the Hyp mutation on kinetically distinct phosphate transport processes in mouse kidney.

We examined the kinetics of phosphate transport in mouse renal brush-border membrane vesicles under initial rate (6 s), trans zero, voltage clamp conditions. Two kinetically distinct Na+-dependent phosphate transport processes were identified: a high-affinity, low-capacity system (Km, 0.09 +/- 0.02 mM; Vmax, 539 +/- 50 pmol/mg protein per 6 s) and a low-affinity, high-capacity system (Km, 1.28 +/- 0.35 mM; Vmax, 1677 +/- 198 pmol/mg protein per 6 s). The high-affinity system was inhibited competitively by 1 mM phosphonoformic acid (PFA) (apparent Ki, 0.31 +/- 0.03 mM) and completely abolished by 20 mM PFA; the low-affinity system was insensitive to 1 mM PFA and was inhibited competitively by 20 mM PFA (apparent Ki, 9.03 +/- 1.21 mM). Dietary phosphate deprivation elicited a significant increase in Vmax of both high- and low-affinity phosphate transport systems whereas the X-linked Hyp mutation caused a 50% decrease in Vmax of the high-affinity system with no change in the low-affinity system. Phosphate deprivation of Hyp mice elicited a 3.5-fold increase in Vmax of the high-affinity system. Neither diet nor mutation significantly altered the apparent Km values of either phosphate transport process. We conclude that (1) mouse kidney brush-border membranes have two distinct Na+-dependent phosphate transport systems which differ in affinity and capacity; (2) both processes participate in the adaptive response to dietary phosphate restriction; (3) only the high-affinity system is impaired by the X-linked Hyp mutation.

Animals↗
PubMed1983

Anaerobic degradation of cyanuric Acid, cysteine, and atrazine by a facultative anaerobic bacterium.

A facultative anaerobic bacterium that rapidly degrades cyanuric acid (CA) was isolated from the sediment of a stream that received industrial wastewater effluent. CA decomposition was measured throughout the growth cycle by using a high-performance liquid chromatography assay, and the concomitant production of ammonia was also measured. The bacterium used CA or cysteine as a major, if not the sole, carbon and energy source under anaerobic, but not aerobic, conditions in a defined medium. The cell yield was greatly enhanced by the simultaneous presence of cysteine and CA in the medium. Cysteine was preferentially used rather than CA early in the growth cycle, but all of the CA was used without an apparent lag after the cysteine was metabolized. Atrazine was also degraded by this bacterium under anaerobic conditions in a defined medium.

Journal Article↗
PubMed1977

Assay of proteolytic activity by gelatin liquefaction (trypsin assay by gelatin liquefaction).

A new assay for proteolytic enzymes and their inhibitors based on the liquefaction of gelatin gels has been developed. The assay is more sensitive than colorimetric tests, can be carried out upon colored or turbid samples and does not require the use of a spectrophotometer. The procedure consists of incubating the test sample with a fluid gelatin solution, cooling the solution so that it sets to a firm gel and then incubating at a warmer temperature until the gel iquefies. The time taken for liquefaction is several days for a sample of pure buffer, about one minute for a sample containing 0.5 microgram of trypsin per ml and longer for samples containing less trypsin, following an empirical calibration. An appreciable decrease in tryptic activity can be detected in the presence of only 0.1 KIU of Trasylol (bovine pancreatic trypsin inhibitor) by this method.

Aprotinin↗
PubMed1973

The frequency of genetic disease and congenital malformation among patients in a pediatric hospital.

A sample of 12,801 admissions to a pediatric hospital was surveyed in 1969-70 to determine the prevalence of disease which could be classified as "genetic" in origin or related to "congenital malformation"."Genetic" admissions accounted for 11.1% of the total while 18.5% were for congenital malformations; about 2% (unknown group) were probably genetic. Therefore about one third of all admissions represent the effect of abnormal gene-environment interrelations at some point in the development or life of the patient.The "genetic" patient is admitted more often to a medical service while the patient with congenital malformation usually goes to a surgical service; the former stays 7.3 days and the latter 8.6 days. A disproportionate number of patients staying longer than 10 days were found in the group with congenital malformations. Seventy percent of the patients with multiple admissions (3.2% of all admissions) have genetic illness or congenital malformation.

Age Factors↗
PubMedDate not supplied

RhD isoimmunization and current management modalities.

OBJECTIVE: To review the literature on current perspectives and treatment of RhD isoimmunization. DATA SOURCES: A search was conducted on MEDLINE and CINAHL, and supplemental articles/ bulletins were obtained from cited references and the Web site of the American College of Obstetricians and Gynecologists. Recent texts also were reviewed. Key search words: isoimmunization, Rho (d) immune globulin, fetal erythroblastosis, intrauterine blood transfusions, alloimmunization. STUDY SELECTION: Articles and comprehensive works from indexed journals in the English language relevant to key words and published after 1995 were evaluated. Historically relevant periodicals and texts were also reviewed and selected. DATA EXTRACTION: Data were extracted and organized under the following headings: testing of the antepartum patient, antepartum treatment of isoimmunization, testing of the postpartum patient, anti-D immune globulin, antepartum anti-D immune globulin prophylaxis, other antepartum and obstetric indications for anti-D immune globulin administration, postpartum anti-D immune globulin prophylaxis, nursing implications, and future possibilities. DATA SYNTHESIS: RhD isoimmunized pregnancies continue to contribute to worldwide perinatal and neonatal morbidity and mortality. This review describes the basic knowledge necessary to care for these pregnancies and the current management modalities. CONCLUSIONS: The management options for RhD compromised gestations continue to evolve almost as quickly as technological advances are made. Multiple areas of research in this field have surfaced, and nurses can become valuable members of these research teams. The literature also indicates that with the available knowledge and resources, the current rate of RhD isoimmunization can be further decreased with closer adherence to proposed management guidelines by all health care professionals.

Female↗