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Biomedical subjects

V James

Publications and source records attributed to V James.

At least 55 records · Page 3Linked to original sources
PubMed1988

Ultrastructural features of acute monoblastic leukaemia cells: a multivariate morphometric analysis.

Morphometric studies were carried out on five ultrastructural measures of size or quantity of some of the intracellular organelles in monoblasts obtained from six patients diagnosed as having acute monoblastic leukaemia and also on monocytes from six normal controls. The morphometric measures were analysed using a one way multivariate analysis of variance (MANOVA) to see whether acute monoblastic leukaemic cells differed from those of normals. It was found that there was a highly significant decrease both in the surface to volume ratio of mitochondria and also in the surface to volume ratio of the nucleus. The possible physiological significance of these structural changes is stressed.

Adult↗
PubMed1988

Loss of polymorphic A and B locus HLA antigens in colon carcinoma.

In the present study we have confirmed that approximately one third of human colorectal carcinomas fail to express the HLA - A,B,C monomorphic determinant reactive with the W6/32 MAb, and 44% express class II HLA antigens as shown by reactivity with NFK-1 MAb. Reduced staining with the W6/32 MAb was not always associated with the loss of beta 2m. In addition, the expression of HLA-A2 and Bw4 class I specific haplotypes on normal colon epithelium and tumour biopsy tissue was assessed. All normal colonic epithelia stained positively with MAb against A2 and Bw4 antigens, but a loss of these determinants was shown on tumour biopsies from patients tissue typed for the respective specificities. Loss of the A2 haplotype was shown in 4 of 15 tumour tissue samples, and loss of Bw4 specificities in 5 out of 7 tissue samples. The failure to detect specific loci determinants was not necessarily associated with loss of reactivity with W6/32 MAb.

Adenocarcinoma↗
PubMed1987

Agonist and antagonist activities at benzodiazepine receptors of a novel series of quinoline derivatives.

Five members of a novel series of quinoline derivatives which all have similar activities on benzodiazepine receptor binding in vitro were compared in a food-motivated conflict and stress-induced ultrasounds models of anxiety and on suprahyoid muscle twitching in urethane-anaesthetised rats. RU 42382, RU 43028 and RU 39419 showed anxiolytic activity in both tests and RU 40410 was an antagonist. RU 40744 inhibited stress-induced ultrasounds but had little activity in the conflict test. Amphetamine-induced suprahyoid muscle twitching was only weakly inhibited by RU 42382 and RU 43028 in comparison with a classical benzodiazepine agonist. Ro15-1788 antagonised RU 42382 indicating that a major component of its action was agonism at benzodiazepine receptors. RU 39419 had no effect, RU 40744 tended to increase and RU 40410 evoked a small but statistically significant increase in twitching. The same rank order was observed in antagonism of a benzodiazepine in the muscle twitching model. RU 42382 was least effective as an antagonist and RU 40410 most effective. RU 39419 had no effect alone but antagonised the decrease of firing rate of cerebellar Purkinje cells induced by a benzodiazepine in urethane-anaesthetised rats. Comparison of in vivo occupancy of benzodiazepine receptors and efficacy in the conflict test in rats suggests a ranking of agonist intrinsic activity: RU 42382 greater than RU 43028 greater than RU 39419. A simple relationship between intrinsic activity at benzodiazepine receptors and structure of the compounds is proposed.

Action Potentials↗
PubMed1987

Activity of some benzodiazepine receptor ligands with reduced sedative and muscle relaxant properties on stress-induced electrocorticogram arousal in sleeping rats.

Arousal of the electrocorticogram induced by intermittent footshocks in sleeping rats was originally developed to detect hypnotic compounds. A modified shortened protocol is described in which a 2.5-hr nonstressed control period is followed by drug or vehicle administration and a further 5.5-hr recording of the electrocorticogram in the presence of intermittent footshock. The arousal induced by the footshock is reversed by the benzodiazepine chlordiazepoxide and by agents that displace brain benzodiazepine binding but that do not possess the muscle relaxant and sedative properties of benzodiazepines (CL218872, premazepam, ZK91296, RU 43028, and CGS9896). Nonstressed arousal during normal waking was reduced to only a small extent by chlordiazepoxide or any of the other agents tested, suggesting that the footshock-induced arousal is sensitive to the anxiolytic properties of such agents.

Animals↗
PubMed1987

Granular common acute lymphoblastic leukaemia in adults: a morphological study.

2 cases of acute lymphoblastic leukaemia characterised by the presence of cytoplasmic inclusions morphologically similar to azurophil granules are described. Azurophil granulation of blasts is one of the cardinal features which differentiate acute myeloid from acute lymphoblastic leukaemia. Although such granulation of lymphoblasts has caused diagnostic confusion in the past, we found that the granules could be distinguished from myeloid azurophil granules both morphologically and by their characteristic cytochemical staining reactions. They were negative for peroxidase/sudan black and chloroacetate esterase, but gave coarse scattered granular positivity for both acid phosphatase and alpha-naphthyl acetate esterase. Both the electron microscopic appearance of the granules and their cytochemical staining reactions suggested that they were lysosomes. Granular ALL does not appear to be associated with any morphological subtype or karyotype; but is strongly associated with the common ALL phenotype. Its prognostic significance remains uncertain. It occurs more frequently than the small number of previous reports might suggest and, given the potential for misdiagnosis, should be more widely recognised.

Adult↗
PubMed1986

Community mental health in two sectors: County Caroni and St. George East--an evaluation.

An evaluation of the community mental health program in Trinidad in two sectors with differing sociological backgrounds is made. Results showed that both sectors had regular outpatient clinics, outpatient group psychotherapy, and mental health officers partly community based. County Caroni had a low admission rate to St. Ann's Hospital, an ongoing education programme, an outpatient club, and an Extended Care Centre with Day Care Centre. The predominant illnesses seen in County Caroni were Alcoholism in the males and Depression and Anxiety States in the females. In St. George East, there was a higher admission rate to St. Ann's Hospital. The education program was irregular. There was an Extended Care Centre in Tacarigua half of which was allocated to psychiatric patients and a Day Care Centre at the Tumpuna Rehabilitation Centre. The most frequent illnesses in St. George East were Schizophrenia and Alcoholism in the males, and Schizophrenia and Depression with equal frequency in the females. The results indicated that the specific needs of each sector were different--hence the need for different approaches. The difficulties of implementing the Community Mental Health programme are discussed.

Ambulatory Care↗
PubMed1985

Actions and interactions of benzodiazepine agonists, antagonists and inverse agonists on suprahyoid muscle twitching.

Amphetamine-induced twitching of the suprahyoid muscle in nialamide-pretreated, urethane-anaesthetised rats was inhibited by the benzodiazepine agonists RU 32007, diazepam and chlordiazepoxide and the GABAA agonist muscimol. Ro15-1788 and CGS 8216 induced slight, or no reduction in twitching, respectively, but reversed the effect of RU 32007 and diazepam. Ro15-1788 did not reverse the effect of muscimol. Picrotoxin reversed both muscimol and RU 32007 effects at a dose which induced only a small increase in twitching alone. Higher doses of picrotoxin markedly increased amphetamine twitching and induced twitching in the absence of amphetamine. Ethyl-beta-carboline-3-carboxylate (BCE) weakly increased twitching and reversed the effect of RU 32007. CL 218872 weakly reduced twitching but also weakly antagonised RU 32007. In rats pretreated with a higher dose of nialamide methyl beta-carboline-3-carboxylate (BCM) and BCE induced twitching. BCE-induced twitching was antagonised by RU 32007, Ro15-1788, CGS 8216, muscimol and weakly by CL 218872. Thus, benzodiazepine agonists inhibit twitching and inverse agonists induce twitching, both being blocked by antagonists. Partial agonism (CL 218872) or partial inverse agonism (CGS 8216) may be detected by differential effects against different inducers of twitching.

Amphetamine↗
PubMed1981

An enzyme linked immunosorbent assay for leucocyte and platelet antibodies.

An enzyme linked immunosorbent assay (ELISA) method for the detection of antibodies to platelets and leucocytes is presented. The method can be used for large numbers of samples. The method is objective when photometers are used. Approximately 50% of all cases of possible autoimmune thrombocytopenic purpura (A.T.P.) and unexplained neutropenia showed positive results. The results obtained using ELISA and standard tests for leucocyte and platelet antibodies are compared. The ELISA tests may also detect immune complexes.

Acute Disease↗
PubMed1980

Stereological studies on chronic lymphocytic leukaemia and hairy cell leukaemia.

Using stereological techniques at the ultrastructural level, 7 quantitative parameters for 7 patients with hairy cell leukaemia, 27 patients with chronic lymphocytic leukaemia, and 8 normal individuals. These quantitative data show clear differences between normal lymphocytes, CLL cells and the abnormal cells of HCL. They also show that it may be possible to subdivide CLL into distinct groups on quantitative criteria.

Cell Nucleus↗
PubMed1979

Intensive plasma exchange in rhesus isoimmunisation.

Intensive plasma exchanges were carried out in a 34-year-old pregnant woman to lower the level of circulating anti-D. The patient proved interesting from a number of serological aspects. The possible protective effect of coexistent ABO incompatibility is discussed. The effect of plasma exchanges on cytotoxic HLA antibodies is also demonstrated.

Adult↗
PubMed1978

Sterelogical analyses of leukaemic cells.

With the development of different treatment schedules for acute and chronic leukaemias it has become essential that a uniform, standardized classification of malignant cell type is achieved. Without a standardized diagnosis it is impossible to compare the results of differing treatment regimes. Present diagnosis is still based on clinical criteria and subjective assessment of cell morphology; objective and quantitative data are required. Stereological analyses are capable of providing quantitative data. Stereological techniques have been applied to the study of malignant cell types in different leukaemias for the first time and quantitative data has been obtained. The nuclear and mitochondrial volume fractions of the cells have been estimated for normal lymphocytes, the lymphocytes of chronic lymphocytic leukaemia, acute lymphoblastic leukaemia, the abnormal cells of hairy cell leukaemia and several other haematological malignancies. The results clearly indicate that the cell types fo different leukaemias possess measurably different properties and that stereological methods can be used to investigate the leukaemic cell quantitatively.

Adult↗
PubMed1976

Airflometer: new toy or worthwhile advance?

The Airflometer provides a useful index of expiratory flow rate and as such it is a worthwhile advance. It can provide an accurate index of FEV1 provided it is individually calibrated. Perhaps the only limitation is the lack of response of the instrument at low flow rates, for example, with an FEV1 of less than one litre. It is remarkably inexpensive.

Adult↗