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Biomedical subjects

M S Hall

Publications and source records attributed to M S Hall.

36 records · Page 2Linked to original sources
PubMed1979

Integrating hospital and family practice posts in vocational training for family medicine.

Postgraduate training programmes for family medicine are developing simultaneously in many different parts of the world. In the UK continuity of care is highly valued but vocational training schemes have not been able to provide continuity of care for patients throughout a three-year training course.In Puerto Rico a vocational training scheme exists in which residents are enabled to integrate their hospital and family practice work throughout a three-year course. This arrangement is described and compared and contrasted with vocational training in the UK.

Continuity of Patient Care↗
PubMed1978

Survival medicine in North Devon.

Last winter, heavy snow and gale force winds isolated a small North Devon village from the outside world for seven days. This paper describes one general practitioner's experience in helping to maintain community morale and health.

Community Medicine↗
PubMed1973

Biosynthesis of the Juvenile Hormones of Manduca sexta: Labeling Pattern from Mevalonate, Propionate, and Acetate.

Using organ culture, high-resolution liquid chromatography, and microchemical techniques, we demonstrated the efficient incorporation in vitro of several radiolabeled precursors into the two juvenile hormones of Manduca sexta. JH II, a homosesquiterpene hormone, reported from M. sexta as well as several other insects, incorporates radiolabel from acetate, mevalonate, and propionate. JH III, a sesquiterpene hormone recently reported as a natural product of M. sexta, incorporates label from acetate and mevalonate, but not from propionate. Based on the position of the labeled atoms in the precursors and upon the position of incorporation obtained from label-distribution data, a scheme for juvenile hormone biosynthesis is advanced.

Journal Article↗
PubMed1973

Isolation, Structure, and Absolute Configuration of a New Natural Insect Juvenile Hormone from Manduca sexta.

Two juvenile hormones are isolated from organ cultures of corpora allata of the tobacco hornworm moth, Manduca sexta Johannson, and are purified by high-resolution liquid chromatography. These are identified as methyl (2E, 6E)-(10R)-10,11-epoxy-3,7,11-trimethyl-2,6-dodecadienoate, a new natural hormone, and methyl (2E,6E) - (10R,11S) - 10,11 - epoxy - 3,7,11 - trimethyl-2,6-tridecadienoate. [(14)C]Methionine is incorporated only into their methoxycarbonyl group. Details of the in vitro techniques and the chemical proof of structures are presented. The significance of the occurrence of a new juvenile hormone and the new techniques used for production, isolation, and identification are discussed.

Journal Article↗
PubMed1972

Effects of renal function on plasma digoxin levels in elderly ambulant patients in domiciliary practice.

An investigation into the relations between the daily dose of digoxin, drug regimen, serum digoxin concentration, and creatinine and digoxin clearance was carried out in a group of elderly ambulant patients in domiciliary practice. Moderate to severe impairment of renal function was found both in patients taking digoxin and in elderly control subjects. Plasma digoxin levels were not related to blood urea concentrations or creatinine clearance. Digoxin clearance was less than creatinine clearance. Now that plasma digoxin levels can be measured relatively easily their estimation should become part of clinical practice.

Aged↗
PubMedDate not supplied

Use of firefly luciferase for ATP measurement: other nucleotides enhance turnover.

Firefly luciferase utilizes only ATP and a few closely related nucleotides as substrates for the formation of luciferyl adenylate which is an intermediate in the bioluminescent reaction sequence that oxidizes firefly luciferin. The enzyme shows two different time courses of light production depending on ATP concentration used: a flash with high concentrations of ATP (> 8 microM) or a fairly constant production of light with lower concentrations of ATP (< 1 microM). Many nucleotides, nucleotide-containing substances and other compounds, when added either prior to or 1 min after the addition of ATP, change the time course of light production. When added before ATP, these compounds yield a reaction mixture in which light production is fairly constant (at the level characteristic of the flash observed with that ATP concentration). When the compounds are added after ATP addition, light production is markedly stimulated and the higher rate of light production is maintained for several minutes. There is an increase in quanta of light produced per luciferase dimer from 1 to 5/min with the addition of any of several nucleotide analogues. These results are consistent with a stimulated release of the inhibitory product oxyluciferin, allowing turnover of the enzyme. This enzyme turnover permits more light output at high ATP concentrations, thus enhancing the sensitivity of enzyme determination.

Adenine Nucleotides↗
PubMedDate not supplied

Stability of firefly luciferase in tricine buffer and in a commercial enzyme stabilizer.

A solution of firefly luciferase in AuthentiZyme Enzyme Stabilizer retains full activity when stored in an ice bath (0.5 degrees C) during one day. These solutions have the advantage that no additional protein (other than the luciferase) is present, which is desirable for proteolytic digestion and protein derivatization experiments. For longer-term experiments, firefly luciferase solutions in 0.05 mol/l Tricine buffer at pH 7.8, 10 mmol/l MgSO4, 1 mmol/l EDTA, and 1 mmol/l DTT which contain 100 micrograms/ml of bovine serum albumin are stable for 6 weeks if frozen and thawed only once.

Animals↗
PubMedDate not supplied

Bioluminescent determination of 0.1 picomole amounts of guanine nucleotides.

A bioluminescence procedure for the determination of the guanylates has been optimized to allow measurement of 0.1 pmol amounts. Modifications of the Karl procedure include the use of purified firefly luciferase and nucleoside diphosphate kinase instead of a crude extract of firefly tails, the use of Tricine buffer instead of the inhibitory arsenate buffer, and optimization of the amounts of reagents and incubation times for each of the partial reactions. In the determination of GMP, background values varied widely with different lots of bovine guanylate kinase. Careful selection of a suitable lot of bovine brain guanylate kinase was essential for determination of lower amounts of guanylates. This establishes that selection of guanylate kinase must be based on experimental determination and not reported adenylate kinase activity. The wide variation in background was not eliminated by the inclusion of adenylate kinase inhibitors.

Adenylate Kinase↗
PubMedDate not supplied

Intravenous iron administration to very-low-birth-weight newborns receiving total and partial parenteral nutrition.

BACKGROUND: Intravenous iron supplements are not routinely administered to very-low-birth-weight newborns receiving total parenteral nutrition because of the possible increased risk of infection and because iron needs may be met with blood transfusions. METHODS: To assess the benefits of a prudent IV iron supplement (200 to 250 micrograms/kg/d), 26 very-low-birth-weight newborns (birth weight, 1005 +/- 302 g; gestational age, 28 +/- 2.3 weeks; mean +/- SD) were randomly allocated to receive total parenteral nutrition without iron (No-Iron) or with iron supplied as iron dextran (Iron). These newborns were followed at baseline (2 to 3 days after birth) and at weeks 1 to 4 thereafter. At each sampling time, urine samples, fecal samples (rarely), unused total parenteral nutrition solutions, blood products, and a blood sample (1 mL) were collected. RESULTS: There were no differences between the two groups in anthropometric measurements, hematologic or biochemical parameters, number or amount of blood transfusions (2.3 +/- 1.9), amount of blood removed for diagnostic purposes (44 +/- 16 mL), or number of septic events (n = 16). There was no difference between the groups for the total iron excreted; however, the Iron group retained more iron. Iron balance was negative for all but 10 newborns (No-Iron, 3; Iron, 7) throughout the study. CONCLUSIONS: A total iron intake of 400 micrograms/kg/d, half of which was provided by IV iron, is not sufficient to maintain iron balance or to meet fetal accretion rates (1000 micrograms/kg/d) in very-low-birth-weight newborns receiving total parenteral nutrition. Furthermore, endogenous iron from blood transfusions does not provide an adequate supply of iron.

Anthropometry↗