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Biomedical subjects

P Hall

Publications and source records attributed to P Hall.

At least 199 records · Page 11Linked to original sources
PubMed1987

Relation among accommodative facility, lag, and amplitude in elementary school children.

Normative data for accommodative lag, facility, and amplitude of children have been presented in the literature for each of the parameters separately. This paper delineates the relation among accommodative amplitude, lag, and flexibility for grade school children. Approximately 200 children were screened. Those who wore corrective lenses, had uncorrected acuity worse than 6/9 (20/30) in either eye, had strabismus, had a refractive error outside the range from 0.00 to +0.75 D; or astigmatism greater than 0.50 D were excluded from the study. Of the 123 who remained, 53% had a deficit in accommodative facility, 26% had a deficit in lag, and 25% had a deficit in amplitude from that which would be expected from their age. Sixteen percent had deficits in both facility and lag. Eighteen percent had deficits in both amplitude and lag. Twenty-four percent had deficits in both facility and amplitude. Only 4% had deficits in all three of the accommodative functions considered--amplitude, lag, and facility. Clinically, these results indicate that when a patient's accommodative dysfunction is examined all facets of accommodation--lag, facility, and amplitude--need to be evaluated.

Accommodation, Ocular↗
PubMed1987

Control of menorrhagia by the cyclo-oxygenase inhibitors naproxen sodium and mefenamic acid.

Thirty-five patients with menorrhagia were treated in a double-blind crossover study with naproxen sodium and mefenamic acid after measurement of their blood loss during control menstrual cycles. Treatment with these compounds reduced the excessive bleeding by an average of 46 and 47% respectively. Drugs in the prostaglandin synthetase inhibitor group are considered to have an important place in the treatment of menorrhagia.

Adolescent↗
PubMed1987

Detection of alpha-1-antitrypsin in hepatocytes in acute and chronic hepatitis.

Twelve of sixteen consecutive needle biopsies of liver with either acute or chronic hepatitis showed positive immunohistochemical staining for alpha-1-antitrypsin (AAT). Only two of the positive biopsies contained numerous, large periodic acid-Schiff positive, diastase resistant (PAS-D) globules in periportal hepatocytes; both patients were Pi MZ but only one had a low serum AAT concentration. The other 15 patients had normal or elevated serum AAT. The accumulation of AAT in hepatocytes, demonstrated by sensitive immunohistochemical staining, may indicate increased synthesis and/or impaired secretion of AAT occurring in association with various types of hepatitis.

Acute Disease↗
PubMed1986

Functional activities and nonenzymatic glycosylation of plasma proteinase inhibitors in diabetes.

The functional activity of three of the major plasma protease inhibitors, alpha 1-proteinase inhibitor, antithrombin III and alpha 2-antiplasmin, has been measured in a series of persons with diabetes mellitus and compared with healthy controls. The mean specific functional activity of both diabetic plasma antithrombin III (50.8 +/- 7.0 U/mg) and alpha 1-proteinase inhibitor (35.3 +/- 5.6 mU/mg) was found to be significantly lower than in healthy controls (57.9 +/- 6.0 U/mg) and (42.2 +/- 10.7 mU/mg). No difference was detected in alpha 2-antiplasmin activity or levels. The glycosylated protein fraction of 83% of diabetic plasmas showed the presence of less than 1% of the total alpha 1-proteinase inhibitor when isolated by phenylboronate affinity chromatography. Incubation of normal plasma with 250 nmol/l glucose (a level approximately 6 X higher than encountered in uncontrolled diabetes) resulted in a 17% and 6% decrease in antithrombin III and alpha 1-proteinase inhibitor activities. We conclude that the decrease in specific activity of alpha 1-proteinase inhibitor is not related to nonenzymatic glycosylation, but the decrease in antithrombin III specific activity may be related.

Adult↗
PubMed1986

The synthesis of aldosterone by the adrenal cortex. Two zones (fasciculata and glomerulosa) possess one enzyme for 11 beta-, 18-hydroxylation, and aldehyde synthesis.

In order to establish the nature of the aldosterone synthetase activity in the adrenal cortex, we have used porcine adrenal, bovine adrenal cortex, highly purified bovine and porcine 11 beta-/18-hydroxylase, and antibodies raised against the latter enzyme. Mitochondria from two zones (glomerulosa and fasciculata) of the bovine cortex synthesize aldosterone, but those from glomerulosa are much more active than those from fasciculata. Partially purified (cholate-extracted plus ammonium sulfate-precipitated) extracts of mitochondria from the two zones are equally active in catalyzing all three steps in the conversion of 11-deoxycorticosterone to aldosterone. 18-Hydroxylase and aldehyde synthetase activities (18-hydroxycorticosterone----aldosterone) were completely precipitated from cholate extracts of mitochondria from bovine adrenal by antibodies to the pure porcine enzyme. No activity corresponding to any of the three steps in the conversion of 11-deoxycorticosterone to aldosterone was found in extramitochondrial fractions of the bovine cortex. Synthesis of aldosterone by the pure porcine enzyme was inhibited by antibodies to this enzyme and by metyrapone (an inhibitor of 11 beta-/18-hydroxylase). When fractions of porcine adrenal, resulting from purification of the enzyme from mitochondria, were exhaustively tested for any of the enzyme activities required for the synthesis of aldosterone, activity was found only in those fractions containing the 11 beta-/18-hydroxylase, i.e. no additional enzyme was discarded during the purification procedure. It is concluded that the only adrenocortical enzyme capable of synthesizing aldosterone in bovine and porcine adrenal is the well known 11 beta-hydroxylase, that the conversion of 18-hydroxycorticosterone to aldosterone is catalyzed by this cytochrome P-450, and that this step (aldehyde synthetase) requires the heme of the P-450 as demonstrated by the photochemical action spectrum.

Adrenal Cortex↗
PubMed1986

Decreasing the incidence of surgical wound infections. Validation of a surveillance-notification program.

In an attempt to validate the observations of a previously published ten-year study of surgical wounds, we studied 8,474 wounds over an 18-month period using a protocol nearly identical to that of the previous study. Our study corroborated the following predictors of clean-wound infection: increasing duration of surgery, age less than 1 or greater than 50 years, increasing duration of preoperative hospitalization, use of drains, and shaving and emergency surgery. We failed to corroborate use of wound irrigation as a protective measure or time of preoperative shaving as a significant variable. Most importantly, we found a 42% reduction in the clean-wound infection rate during the study period (1.9% to 1.1%), adding support to the concept that a wound surveillance program with surgeon notification is both efficacious and cost-effective.

Adolescent↗
PubMed1986

An evaluation of orcein methods for demonstrating hepatitis B surface antigen and copper-associated protein in human liver.

Difficulties were encountered with the orcein method currently being used to demonstrate hepatitis B surface antigen and copper-associated protein in the liver when a new batch of dye was introduced. A survey of published material produced a plethora of methods with many contradictory recommendations. A number of methods and a variety of orceins were compared to determine which methods and orcein solutions would give the most consistent results. Two methods gave equally satisfactory results and can be recommended for routine use in screening paraffin sections of liver for hepatitis B surface antigen and copper-associated protein.

Hepatitis B↗
PubMed1986

Impact of hormonal contraceptives vis-à-vis non-hormonal factors on the vitamin status of malnourished women in India and Thailand. World Health Organization: Special Programme of Research, Development and Research Training in Human Reproduction. Task Force on Oral Contraceptives.

The effects of combined oral contraceptives containing 30 or 50 micrograms ethinyl oestradiol and 150 micrograms levonorgestrel or a 3-monthly injectable preparation depo-medroxyprogesterone acetate (DMPA) on the vitamin status of low-income group women from two urban centres in India (Bombay and Hyderabad) and one rural centre in Thailand (Chiang Mai) were examined in a follow-up study over a period of 1 year. The magnitude of malnutrition in the study population vis-à-vis a middle-income reference group was assessed by comparing the baseline data on the two groups. Effects of time-related variables such as lactation and season were also examined by a cross-sectional analysis of the baseline data on the study population. In all three centres the majority of the study population suffered from biochemical riboflavin and/or pyridoxine deficiency even before initiating contraception. Lactation appeared to have an effect on the vitamin status, which varied among the different populations. Seasonal effects were seen, but showed inconsistent trends in the three centres. Both the oral contraceptive pills and DMPA tended to increase serum vitamin A and blood folate. The thiamin, riboflavin and pyridoxine status of the women who were already deficient did not deteriorate further with the use of hormonal contraception, as judged by enzyme saturation tests. Some deterioration in the riboflavin status of the normal women of Hyderabad was seen with the use of oral pills. Women who were biochemically deficient prior to the use of oral contraceptives tended to show some improvement in B-vitamin status, over the 1-year period of hormonal contraception.

Adolescent↗
PubMed1985

Estimation of indole-3-acetic acid in gametophytes of the moss, Physcomitrella patens.

By means of gas chromatography-selected ion monitoring-mass spectrometry using an isotope-dilution assay with 4,5,6,7-tetradeutero-indole-3-acetic acid as the internal standard, indole-3-acetic acid has been estimated to be present in aseptically cultured gametophytes of wild-type Physcomitrella patens (Hedw.) B.S.G. at a level of 0.075 microgram g-1 dry weight or 2.1 ng g-1 fresh weight.

Bryopsida↗
PubMed1983

A glycogen storage disease in rats. Morphological and biochemical investigations.

Liver and heart from a substrain of the NZR/Gd rat in which there is an inherited deficiency of liver phosphorylase b kinase was examined by light and electron microscopy and compared to material from a related, but normal substrain. Hepatic tissue differed markedly from that of control animals. Hepatocytes contained more than twice as much free glycogen and visible lipid. Glycogen particles had an abnormal appearance and some glycogen was sequestered within large, membrane-bound vesicles. Hepatocyte lysosomes were increased by a third and mean cell volume by more than half. Lobular architecture was distorted by the presence of enlarged, irregularly-shaped hepatocytes. Free glycogen was present in the space of Disse and sinusoids and within lysosomes in Kupffer cells. There were increased amounts of collagen in the space of Disse. The changes resemble those described in human glycogen storage disease IXa. A study of hepatic tissue from fasted rats showed that affected animals have an impaired ability to mobilise their liver glycogen stores. An increase in visible lipid also occurred in affected, fasted animals. Cardiac tissue appeared to be normal.

Animals↗
PubMed1983

Review of pulsing electromagnetic field therapy and its possible application to horses.

The relevant literature on electrostimulation in general, and pulsing electromagnetic fields in particular, is reviewed. DC current influences cell behaviour by affecting transmembrane ion transport, which is often under enzymatic control. Pulsing electromagnetic fields influence cell functions through adsorption of ions or dipole formation at the cell membrane. Invasive and non-invasive DC current stimulation is compared to pulsing electromagnetic fields. The mode of application of pulsing electromagnetic fields to the equine limb and suggested treatment times are briefly discussed. Two case reports are used to illustrate the effect of pulsing electromagnetic fields in equine fracture treatment.

Animals↗
PubMed1983

Intravenous metronidazole in the newborn.

Twenty four neonates at high risk of anaerobic sepsis were treated with intravenous metronidazole, 7.5 mg/kg, 8 hourly, for a mean period of 5 days. The highest observed concentration after the first dose (mean +/- SD) 9.6 +/- 4.0 mg/l (56.1 +/- 23.4 mumol/l) was significantly lower (P less than 0.001) than the highest observed concentration after the final dose (mean +/- SD) 19.3 +/- 8.6 mg/l (112.7 +/- 50.2 mumol/l). The overall metronidazole half life was (mean +/- SD) 23.4 +/- 13.1 hours. The half life after the first dose (mean +/- SD) 21.9 +/- 10.1 hours was not appreciably different from the half life after the final dose (mean +/- SD) 21.6 +/- 12.4 hours. The concentrations of the major metabolite of metronidazole (20396RP) also rose appreciably during treatment. No side effects of metronidazole were noted and its extended half life in neonates suggests that less frequent dosage would be appropriate.

Bacterial Infections↗
PubMed1983

Fetal renal maturation. Studies on urinary beta 2 microglobulin the neonate.

Beta 2 microglobulin [B2m] and creatinine [Cr] concentrations were measure in the urine of 27 newborn infants. At birth, urinary [B2m] and [B2m]/[Cr] ratios were significantly lower in infants born beyond 36 weeks' gestation. Serial measurements, postnatally, showed a progressive decrease in the urine [B2m]/[Cr] ratio of infants born prematurely. These findings suggest an increase in tubular uptake of B2m with increasing gestational and postnatal age. The current findings tend to support the hypothesis that the decrease in [B2m] observed in amniotic fluid beginning at approximately 36 weeks' gestation reflects maturation of fetal proximal renal tubular function.

Amniotic Fluid↗