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Biomedical subjects

L Wood

Publications and source records attributed to L Wood.

At least 217 records · Page 12Linked to original sources
PubMed1984

Oral iron therapy in human subjects, comparative absorption between ferrous salts and iron polymaltose.

Iron absorption was directly compared between equivalent doses of ferrous salts and a polymaltose complex using a twin-isotope technique in which each individual acts as his own control. In the first study, bioavailability of iron from ferrous sulfate and the complex was defined at physiologic doses of 5 mg (Group 1: n = 14) and therapeutic doses of 50 mg (Group 2: n = 13). In Group 1, mean absorption from salt was 47.77% (SD 14.58%) and from polymaltose, 46.56% SD 17.07%). In Group 2, mean absorption from salt was 32.92% (SD 13.42%) and from polymaltose, 27.07% (SD 6.50%). In a second study, 100 mg of iron in a chewable formulation was used to compare absorption between equal doses of ferrous fumarate and the polymaltose complex. Mean absorption from salt was 10.25% (SD 6.89%) and from polymaltose 10.68% (SD 4.68%). At all three dosage levels, iron is equally available from salt or polymaltose for hemoglobin synthesis (p greater than 0.20), and absorption negatively correlated with plasma ferritin (p less than 0.01). These two materials may be used interchangeably in the treatment of patients with absolute iron deficiency.

Absorption↗
PubMed1984

Patients with delusional and bizarre thinking.

Patients with delusional or other types of bizarre thinking are often incorrectly labeled as schizophrenic. This error has significant medical and social implications to the patient. Delusional thinking has been linked with a variety of nonschizophrenic problems including the use of licit and illicit drugs, a wide variety of medical diseases, and nonschizophrenic psychiatric disturbances. A series of case studies in which the diagnosis of schizophrenia was incorrectly made elucidates the problem and helps the physician consider the alternatives.

Adolescent↗
PubMed1983

Activity of lysosomal cysteine proteinase during differentiation of rat skeletal muscle.

Cysteine-proteinase activities were measured in extracts of pre- and post-fusion populations of rat myogenic line L6 cells and in extracts of whole rat muscle. Activities of cathepsins B, L and H were compared. The substrates used included Z-Phe-Arg-NMec (cathepsins B and L), Z-Arg-Arg-NMec (cathepsin B), and Arg-NMec (cathepsin H) (where Z = benzyloxycarbonyl, and NMec = 4-methyl-7-coumarylamide); the enzyme activities were more specifically differentiated by appropriate concentrations of the inhibitors Z-Phe-Phe-CHN2 (CHN2 = diazomethane), bestatin and E-64 [L-trans-epoxysuccinyl-leucylamido(4-guanidino)butane]. These experiments have demonstrated the feasibility of determining the cysteine-proteinase activities of myoblasts from a single (60 mm-diameter) Petri dish, with enzyme concentrations in the range of 5-20 ng/ml. Specific activities of the enzymes in L6 cells increased 2-20-fold after fusion. Concentrations of cysteine proteinases in extracts from cultured myoblasts were two orders of magnitude greater than those in muscle-tissue extracts. Cultured-cell extracts contained endogenous inhibitor(s) to purified rat cathepsins B, L and H.

Animals↗
PubMed1983

Linked pools of processed alpha-mannosidase in Dictyostelium discoideum.

We are studying the fate of alpha-mannosidase, a lysosomal enzyme, in Dictyostelium discoideum. alpha-Mannosidase is synthesized as a 150,000-dalton precursor which becomes proteolytically cleaved to mature (56,000-62,000 dalton) forms. When cells are shifted into starvation buffer (5 mM phosphate, pH 6.5), the enzyme is secreted. We compared the kinetics of secretion of newly processed alpha-mannosidase with that of bulk forms. After 2 h in phosphate buffer less than 20% of the newly processed forms but as much as 50% of the bulk enzyme activity was secreted. During the course of the experiments, the total alpha-mannosidase activity remains constant, cells remain viable, and there is no evidence of degradation of enzyme. Furthermore, a 4-h chase period prior to starvation is required before the newly processed forms are secreted to the same extent as the bulk forms. On the basis of these results we propose that the enzyme is present in at least two pools and that it is transferred from a newly processed to an efficiently secreted pool.

Dictyostelium↗
PubMed1983

Comparison of the lipid composition of breast milk from mothers of term and preterm infants.

Milk was collected from mothers of 18 very premature (26 to 30 wk gestation age), 28 premature (31 to 36 wk), and six term (37 + wk) infants on day 2 to 3 (colostrum), and at 1, 3, 6, and 12 wk postpartum. Fat content for 154 milk samples was 2.80 g/dl gravimetrically and 2.66 g/dl by quantitative thin-layer chromatography. Fat content increased during lactation, whereas phospholipids and cholesterol declined. Concentrations of medium-chain fatty acids increased from colostrum to mature milk and were highest in preterm milk. Compensatory decreases were observed in very premature and premature oleic acid. Long-chain polyunsaturated fatty acids were highest in colostrum and reduced in mature milk. Long-chain polyunsaturated fatty acids were also higher in very premature and premature milk than in term milk. These elevated levels of readily absorbed medium-chain fatty acids and long-chain polyunsaturated fatty acids in preterm milk may be of special benefit for the needs of premature infants.

Adolescent↗
PubMed1983

Comparison of ranitidine and cimetidine in the treatment of chronic gastric ulcer. A double-blind trial.

The aim of the study was to compare the effectiveness of ranitidine and cimetidine in accelerating the healing of chronic gastric ulcer. 44 outpatients with endoscopically proven gastric ulcer whose duration of symptoms was greater than 4 weeks and who were without major systemic disease were studied. Patients were randomly allocated to receive either ranitidine, 150 mg twice a day or cimetidine, 200 mg three times a day and 400 mg at night for 4 weeks. If the ulcer had not healed, treatment was continued for a further 4 weeks, when patient assessment and endoscopy were repeated. By 4 weeks, 13 of 22 patients taking ranitidine (59%) and 14 of 22 patients taking cimetidine (64%) had healed (p2 = 1.0, 95% confidence interval - 20%, 38%). At 8 weeks, 91% on ranitidine and 91% on cimetidine had healed (p2 = 1.0, 95% confidence interval - 18%, 18%). Symptomatic improvement was similar with both drugs. Smoking did not influence healing rates. There were no major side effects with either medication. It is concluded that ranitidine and cimetidine are of similar efficacy in accelerating the healing of chronic gastric ulcer.

Adolescent↗
PubMed1983

The patient exhibiting episodic violent behavior.

This case presentation describes a 21-year-old white male patient seen for episodic violent behavior. The case is seen as relevant for primary care physicians because of the frequency of violent acting out in the general population, the importance of making an accurate diagnosis, and the many medical, psychological, and social implications involved in diagnosing such disorders. In such cases it is important that the physician keep an open mind and include within the differential diagnosis a variety of psychiatric disturbances such as paranoid schizophrenia, antisocial personality disorder, drug abuse syndromes including a variety of hallucinogens as well as prescription medication, organic diseases affecting the central nervous system, including encephalitis and temporal lobe epilepsy, and a variety of interpersonal difficulties, including spouse abuse and spousal rape. The case presentation method demonstrates how the psychiatric interview and a judicious use of biochemical and physiological testing can lead the practitioner to a correct diagnosis.

Adult↗
PubMed1982

Red cell phospholipids in schizophrenia.

Phospholipids in red blood cells (RBCs) of schizophrenics and controls were determined. Three different RBC preparations and two different extraction methods were used. Phospholipids were separated by thin layer chromatography and by high pressure liquid chromatography, and were quantified by phosphorus analysis and by ultraviolet absorption. Findings were consistent with values previously reported for normals. However, in contrast to recent reports of elevated phosphatidylserine levels in schizophrenics' RBCs, we observed no differences between populations.

Adult↗
PubMed1982

Processing and secretion of alpha-mannosidase forms by Dictyostelium discoideum.

We are studying the biosynthesis and processing of acid hydrolases from Dictyostelium discoideum. We prepared antibody to highly purified alpha-mannosidase from the spent medium of stationary phase cultures. It precipitated alpha-mannosidase but not beta-hexosaminidase, alpha-glucosidase, beta-glucosidase, or any of the major proteins in cell lysates or secretions. The antibody precipitated a 150,000- and an 80,000-dalton protein in addition to mature forms (56,000-62,000 daltons) of alpha-mannosidase subunits. The possibility that the 150,000 and 80,000 dalton bands were precursors of mature forms was evaluated by pulse-chase experiments. Following a 20-min pulse labeling period, only the 150,000-dalton protein was detected in the immunoprecipitate. Apparent conversion of this form into 80,000- and 60,000-dalton forms was observed following a 30-min chase. During the next 90 min continued accumulation of 60,000-dalton and appearance of 62,000-dalton forms was observed while the 80,000-dalton form disappeared. The fate of the 150,000-dalton precursor depended on nutritional conditions. In cells conditioned with fresh growth medium intracellular processing predominated. Less than 10% of either the precursor or mature forms was secreted in 8 hr. However, when cells were shifted from growth medium to starvation buffer, secretion of precursor soon predominated. After a 1-hr lag period, cells began secreting 150,000-dalton precursor into the medium. After 4 hr in starvation buffer, the rate of secretion of 150,000-dalton form increased by at least an order of magnitude while processing was markedly diminished. This may be a case where nutritional conditions control the sorting of an acid hydrolase precursor.

Antibody Specificity↗
PubMed1981

The role of continuous-flow blood fraction separators in clinical practice.

Continuous-flow blood fraction separators facilitate the efficient exchange of large volumes of plasma or red cells and therefore have clinical application in the rapid correction of abnormalities located predominantly in either of these compartments. Plasmapheresis has been successfully used in managing 2 patients with previously refractory myasthenia gravis, in reducing the antibody titre in a rhesus-sensitized woman, and in diminishing anti-A titre in a patient requiring bone marrow transplantation from an ABO-incompatible but HLA- and MLC-identical sibling. Continuous-flow red cell exchange effectively reduced the haemoglobin S concentration in an individual with sickle cell disease prior to general anaesthesia and abdominal surgery. Complications were not encountered although the procedures were carried out repetitively over prolonged periods of time. All 5 patients tolerated their exchanges without discomfort. As with any new and expensive technique, caution should attend the introduction of continuous-flow plasma or red cell exchange into clinical medicine. Careful evaluation of the safety and the benefits is needed to establish perspective and to distinguish between established and developmental indications.

Acetylcholine↗
PubMed1981

Cimetidine impairs the elimination of theophylline and antipyrine.

In 7 healthy subjects theophylline and antipyrine elimination were determined before and during a course of oral cimetidine in a dose of 1 g/day. Plasma clearance of theophylline was reduced from 71.2 +/- 10.1 ml/min to 56.0 +/- 18.5 ml/min and the plasma clearance of antipyrine from 53.7 +/- 14.2 ml/min to 48.1 +/- 11.7 ml/min. Elimination half-life of theophylline was prolonged from 5.1 +/- 1.6 to 8.1 +/- 1.4 h. All these changes were statistically significant. Volume of distribution of theophylline (31.7 +/- 8.4 L before and 39.2 +/- 5.6 L during cimetidine administration) and plasma binding of theophylline (44.7 +/- 3.8% before and 44.3 +/- 3.1% during cimetidine administration) were not significantly different. Similarly, volume of distribution of antipyrine (45.8 +/- 14.0 vs. 47.6 +/- 17.9) was not significantly affected by cimetidine administration. We conclude that cimetidine impairs the elimination of theophylline and antipyrine in healthy subjects.

Adult↗
PubMed1981

Domestic breeding of patas monkeys (Erythrocebus patas).

Two reproductive strategies were used in the management of a patas monkey (Erythrocebus patas) breeding colony. The first strategy involved placement of all animals into one-male harem units for breeding, parturition, and infant rearing. The second strategy involved a reduction in the number of males, movement of pregnant females to individual cages, and formation of new groups with females and neonates. The second strategy resulted in an increased percentage of females having successful births and an increased survival of neonates. The percentage of females becoming pregnant did not change.

Animals↗
PubMed1979

Effects of frontalis EMG feedback and reinforcement on frontalis EMG level.

This experiment employed a between-subjects design (N = 40) to investigate the effects of feedback and reinforcement on the lowering of frontalis electromyographic (EMG) activity. The feedback and reinforcement manipulations were combined in a 2 x 2 factorial design and each subject underwent one baseline and two training sessions on three consecutive days. The analogue feedback signal was a 55 dB tone whose pitch varied as a function of EMG activity, while the reinforcement consisted of points which were exchangeable for money. The training sessions were each divided into 10 2-min baseline periods and 10 2-min trial periods. The results indicated that although analogue feedback did not result in lowered EMG levels, trial period EMG level was significantly lower than baseline level under conditions of reinforcement. These results pose problems for Budzynski and Stoyva's (1972) views concerning the therapeutic usefulness of frontalis EMG feedback training.

Adolescent↗