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Biomedical subjects

A Martin

Publications and source records attributed to A Martin.

At least 649 records · Page 36Linked to original sources
PubMed1988

Intellectual function following penetrating head injury in Vietnam veterans.

The extent to which intellectual processes are preserved as a function of preinjury 'intelligence' and of size and location of the brain lesions was evaluated in Vietnam war veterans who survived penetrating missile wounds. With regard to an overall postinjury intelligence test score, preinjury intelligence was most predictive, size of lesion was next most predictive and lesion location was least important. For subtest scores from the same intelligence test, lesion location assumed much greater predictive value. Specifically, left temporal and occipital lesions impaired performance on subtests assessing vocabulary and object-function matching ability.

Adult↗
PubMed1988

TDM of theophylline--compliance evaluation.

Non-compliance to dosage regimes is an important clinical problem with severe repercussions for the management of chronic illnesses requiring continued treatment. In the present study, we evaluated the degree of non-compliance in a group of 100 patients with chronic asthma undergoing continued treatment with theophylline, and the effect of the application of a monitoring programme on their degree of compliance. The evaluation was carried out by anamnesis and from the level/dose ratio. In the control group studied (n = 50) the degree of non-compliance was 44% and in the previously monitored group (n = 50) it was 18%. Serum theophylline levels in the former were: 7.6 +/- 5.8 micrograms/ml, significantly lower (P less than 0.005) than that observed in the latter: 10.1 +/- 4.0 micrograms/ml. The use of monitoring programmes can improve the degree of compliance.

Adolescent↗
PubMed1988

Anaphylaxis to amoxycillin but good tolerance for benzyl penicillin. In vivo and in vitro studies of specific IgE antibodies.

Three patients are reported on who suffered anaphylactic reactions after amoxycillin (AX) treatment and challenge but tolerated benzylpenicillin (BP) parenterally and orally. Two of the three patients had positive skin tests and RAST to AX reagents but negative responses to benzyl penicilloyl (BPO) specific skin tests and RAST and the minor determinant mixture (MDM) skin test reagent. The third case was negative to all skin tests and RAST. RAST and RAST inhibition on the two positive sera suggest that the response is related to the acyl side chain of AX.

Adult↗
PubMed1988

Expression of polymorphic B-cell antigens on human kidneys.

We have examined the expression on a panel of 22 human kidneys of polymorphic B-cell determinants recognized by mouse monoclonal antibodies. Monoclonal antibodies from a mouse immunized with an antigenic preparation from a DR4 positive B-cell line reacted preferentially with kidneys from DR4 positive donors (p less than 0.005), and the pattern of reactivity with kidney tissues was similar to that of antibodies to monomorphic determinants of class II. However, these antibodies did not show clear specificity for DR4 on lymphocytes in standard serological analyses. These results provide evidence for the expression of polymorphic class II determinants on human kidneys. Reasons for the differences in the apparent specificities of the monoclonal antibodies when tested on kidney sections and lymphocytes are discussed.

Absorption↗
PubMed1988

Study of the fucosyltransferase system in intestinal microsomes.

Fucosyltransferase activity of rat small intestine microsomes is solubilized by 0.5% Triton X-100. The solubilized activity can be purified up to 8,300-fold using DEAE-cellulose and affinity chromatography on GDP-Sepharose. At this step, chromatography on Sephadex G15 separates different specificities: N-acetylglucosaminide-alpha-(1,3)-fucosyltransferase acting on asialoserotransferrin, and galactoside-alpha-(1,2)-fucosyltransferase acting on O-glycans of asialofetuin. The use of small saccharidic acceptors also indicates the presence of a N-acetylglucosaminide-alpha-(1,4)-fucosyltransferase and of a very weak glucose-alpha-(1,3)-fucosyltransferase activity. These activities are tightly bound to concanavalin A-Sepharose, suggesting that they are supported by N-glycosylproteins.

Animals↗
PubMed1988

An open comparative study of two diuretic combinations, frusemide/amiloride ('Frumil') and bumetanide/potassium chloride ('Burinex' K), in the treatment of congestive cardiac failure in hospital out-patients.

Forty elderly patients, aged 68 to 89 years, with congestive cardiac failure, who were attending a hospital out-patients department, entered an open, parallel group, comparative study of two diuretic combinations, 40 mg frusemide plus 5 mg amiloride per tablet and 0.5 mg bumetanide plus 573 mg slow-release potassium chloride per tablet. Patients were assigned at random to receive one or other combination for 8 weeks, dosage being determined by the severity of the individual patient's condition (range 1 to 3 tablets frusemide/amiloride; 2 to 6 tablets bumetanide/potassium chloride). Clinical assessments, including visual analogue scores for dyspnoea at rest and on effort, and laboratory measurements of serum potassium and magnesium levels were carried out on entry and after 2, 4 and 8 weeks of treatment. Other variables were monitored before, during and/or after treatment. Although significant decreases were reported in dyspnoea severity scores at rest and on effort only in the bumetanide/potassium chloride group, global assessment of the patients' condition by patient and clinician at the end of the study indicated that both treatments produced improvement, and a greater proportion of patients considered treatment as satisfactory in the frusemide/amiloride group. Both drug combinations were well-tolerated and only a few minor side-effects were reported. Serum potassium levels were maintained in both treatment groups but there was a significant decrease in mean serum magnesium levels in patients on bumetanide/potassium chloride. Hyponatraemia was also detected in 2 patients on this combination. An increase in body weight was recorded in both groups, the increase being significant in patients receiving bumetanide/potassium chloride.

Aged↗
PubMed1988

[Value of scintigraphy using labelled polynuclears in the diagnosis of infection of a joint prosthesis].

Fifty-three patients with suspected infection of prosthetic joints had Indium-111 granulocyte scintigraphy. Twenty-nine of them had associated technetium-99m phosphate scans. Labelled granulocyte sensitivity was 82% and specificity 100% for the group of 47 patients with suspected late infection. Technetium phosphate sensitivity was 92% and specificity 25%. The main quality of labelled granulocyte scintigraphy is its high specificity: there were no false positives in our series. Its main limitation seems to be that sensitivity is sometimes only moderate: we had 4 false negatives. The probable explanation is the histological characteristics of bone infection: vascular thromboses occur frequently and at an early stage, the inflammatory infiltrate is not very abundant and often has a low granulocyte content. The method is therefore reliable and can be used in situations where diagnosis of periprosthetic infection is difficult with conventional techniques.

Evaluation Studies as Topic↗
PubMed1988

Glycosyl-transferase activities in pancreas: comparison between semi-synthetic and commercial diets.

The glycosyl-transferase activities in the rat pancreas have been previously demonstrated to be modified by the quantity of different dietary components (lipids or proteins). To evaluate the role of the qualitative composition of the diet on such enzymic systems, two groups of rats were fed either a semi-synthetic diet or a commercial diet of very similar quantitative composition but differing in the quality of their components. The two diets induce a quite similar growth of animals, although the pancreas weight of the commercial-diet-fed rats is slightly higher. The galactosyl-, fucosyl- and mannosyl-transferase activities are more or less highly enhanced by the commercial diet according to the enzyme studied. The highest increase is observed for the biosynthesis of mannosyl-phosphoryl-dolichol. This enhancement by the commercial diet disappears when exogenous phosphoryl-dolichol is added. Such results indicate that the mannose transfer is probably modified by an increased level of the pancreatic lipidic acceptor.

Animals↗
PubMed1987

Infrared studies of fully hydrated unsaturated phosphatidylserine bilayers. Effect of Li+ and Ca2+.

Infrared spectroscopy has been used to characterize the thermal-phase behavior of fully hydrated 1-palmitoyl-2-oleoyl-sn-glycero-3-phospho-L-serine (POPS) and 1,2-dioleoyl-sn-glycero-3-phospho-L-serine (DOPS) as well as their interaction with Li+ and Ca2+. The order-disorder transition of POPS-NH4+ is at 17 degrees C; in the presence of Li+ a POPS-Li+ complex is formed, and the transition temperature of this complex is 40 degrees C. DOPS-NH4+ has an order-disorder transition at -11 degrees C, and unlike POPS the addition of Li+ has no effect on the thermal behavior of DOPS-NH4+. This indicates that the binding of Li+ to DOPS is negligible or very weak. Li+ binds to the phosphate and carboxylate groups of POPS, and as a result these groups lose their water of hydration. Li+ binding induces a conformational change, probably in the glycerol backbone of POPS; however, the conformation of the two P-O ester bonds remains gauche-gauche as in POPS-NH4+. Both POPS and DOPS form crystalline complexes with Ca2+. As a result of Ca2+ binding to the phosphate, this group loses its water of hydration and there is a conformational change in the P-O ester bonds from gauche-gauche to antiplanar-antiplanar. In contrast to the POPS-Li+ complex, the carboxylate group remains hydrated in the Ca2+ complexes. Furthermore, in these PS-Ca2+ complexes a new hydrogen bond is formed between one of the ester C=O groups and probably water. Such a situation is not found in the NH4+ and Li+ salts of phosphatidylserine.

Calcium↗
PubMed1987

Relative selectivity of some conformationally constrained tryptamine analogs at 5-HT1, 5-HT1A and 5-HT2 recognition sites.

In an attempt to define pharmacophoric differences between 5-HT1, 5-HT1A and 5-HT2 recognition sites, a number of rigid analogs were studied and compared to analogous free chain tryptamines. Racemic partial ergolines RU 27849 and RU 28306 showed reduced potency at all 5-HT1 sites, but were at least equipotent to analogous tryptamines at the 5-HT2 site. A nonergoline-like constrained analog of tryptamine was similar in potency to RU 27849 at all 5-HT1 sites, but showed a 4-fold enhancement in potency over RU 27849 and tryptamine at the 5-HT2 site. At all 3 sites, 3-(tetrahydropyridyl) indoles (unless substituted at the indole 2-position) were the most potent rigid analogs studied and represent the most promising class for the development of selective compounds.

Animals↗
PubMed1987

A rapid assay for measuring the activity and the Mg2+ and Ca2+ requirements of phosphatidate phosphohydrolase in cytosolic and microsomal fractions of rat liver.

1. A rapid extraction and purification scheme was designed for the recovery of [3H]diacylglycerol formed during the assay of phosphatidate phosphohydrolase. 2. The importance of removing polyvalent cations, particularly Ca2+, from the phosphatidate and other reagents used in the assay of the phosphohydrolase activity was demonstrated. This was achieved mainly by treating the phosphatidate with a chelating resin and by adding 1 mM-EGTA and 1 mM-EDTA to the assays. 3. The activity of the phosphohydrolase in dialysed samples of the soluble and microsomal fractions of rat liver was very low. 4. Addition of optimum concentrations of MgCl2 resulted in a 110-167-fold stimulation in activity. 5. CaCl2 was also able to stimulate phosphohydrolase activity, but to a much smaller extent than MgCl2. 6. Chlorpromazine, an amphiphilic cation, inhibited the reaction when it was measured in these experiments by using a mixed emulsion of phosphatidylcholine and phosphatidate at pH 7.4. 7. Microsomal fractions that were preincubated with albumin contained very low activities of the Mg2+-dependent phosphohydrolase. When these were then incubated with the soluble fraction in the presence of oleate, the soluble phosphohydrolase attached to the microsomal membranes, and it retained its high dependency on Mg2+.

Animals↗
PubMed1987

A new epitope of the T200 molecule family defined by the 3A35 monoclonal antibody and expressed by macrophages and activated T lymphocytes.

A monoclonal antibody (mAb), 3A35, produced against mouse macrophages (M phi) was found to react against certain activated T cells. This mAb, a rat IgM, resulted from a cell fusion between a mouse plasmacytoma and rat lymphocytes immunized against mouse M phi. It bound more avidly to activated than to resident M phi. It did not react against B cells and resting T lymphocytes but recognized certain dividing T cells like EL4 lymphoma, concanavalin A-activated and interleukin 2-expanded spleen cells, and helper T cell hybridomas. By contrast, other T lymphocyte-derived cell lines such as YAC-1 and CTLL2 were unreactive. No clear relationship was found between the binding of 3A35 to cells and the expression of L3T4 and Lyt-2 antigens. The specific stimulation of T cell clones with antigen rapidly induced a strong reactivity with 3A35 mAb which declined thereafter to a low (helper clones) or non-reactivity (cytotoxic clones) after 10 days of culture. Immunoprecipitation experiments, performed with M phi derived from bone marrow cell cultures, surface iodinated with 125I or metabolically labeled with [35S]methionine, showed that 3A35 bound to a 200-kDa molecule, shifting to 175 kDa under reducing conditions. In peritoneal M phi activated in vivo, in addition to the 175-kDa band, new bands migrating at 140, 120 and 85 kDa were identified by 3A35 and could be absorbed on a commercial anti-T200 mAb bound to Sepharose beads. After strengthening the cell binding of 3A35 to EL4 lymphoma cells by a cross-linking agent, only a 85-kDa molecule was immunoprecipitated. Thus, 3A35 identifies a new epitope of the T200 molecule family which is expressed on M phi and activated T cells.

Animals↗
PubMed1987

A monoclonal antibody (Po66) directed against human lung squamous cell carcinoma immunolocalization of tumour xenografts in nude mice.

Po66, a mouse IgG1 monoclonal antibody, was produced by immunization against a patient lung squamous cell carcinoma. The tissue reactivity of the antibody was measured by a radioimmunological assay with enzymatically dissociated cells, by an immunofluorescence test on frozen tissue sections and by peroxidase-staining of paraffin sections. The antibody bound to lung squamous cell carcinoma, oesophagus carcinoma and, inconsistently to lung adenocarcinoma but not to the other tumours tested. Some normal tissues also reacted positively, in particular bronchial serous glands, oesophagus epithelium and renal distal and collecting tubules. In normal and malignant tissues showing epithelioid differentiation, Po66 bound to the intermediate maturation area. The antigen immunoprecipitated by Po66 from lung squamous cell carcinoma appeared as a single band with a molecular weight 47,000 to 50,000 daltons. Purified monoclonal antibody Po66 and an unrelated IgG1 immunoglobulin were labelled with radioactive iodine and injected i.v. into nude mice bearing subcutaneous xenografts of human lung squamous cell carcinoma. The localization index in the tumour was 3.3. Antibody labelled with 131I allowed gamma-scintigraphic imaging of the xenografts which were clearly outlined by days 9 to 11.

Animals↗
PubMed1987

Screening of degradative enzymes from articular cartilage in experimental osteoarthritis.

Sixteen rabbits were killed 12 weeks after sectioning of the right knee anterior cruciate ligament. The left unoperated knee served as a control. The surface area of fibrillated cartilage from femoral condyles and tibial plateau was evaluated and expressed as a percentage of articular surfaces area. Cartilage from the femoro-patellar surfaces was homogenized for the quantification of several degradative activities, based on the release of digested products. Acid phosphatase, several glycosidases and neutral protease activity from the operated joint cartilage were significantly elevated, while collagenolytic activity was unmodified. The percentage of fibrillated cartilage correlated positively with arylsulfatase, glucosidase and neutral protease but negatively with mannosidase and fucosidase. The results may be consistent with the hypothesis of a sequential degradative process leading to cartilage destruction.

Animals↗
PubMed1987

Study of circadian correlations between acetylcholine muscarinic receptor and brain glycosyltransferases by multivariate analysis.

Circadian variations of the acetylcholine muscarinic receptor and some glycosyltransferases were studied in brain using multivariate analysis. Highly significant correlations exist between fucosyltransferase, sialyltransferase and galactosyltransferase and to a lesser extent between both of these enzymes and acetylcholine receptor. No correlation appeared between these enzymes and dolichol phosphate mannose synthase.

Analysis of Variance↗