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Biomedical subjects

G Harrison

Publications and source records attributed to G Harrison.

At least 127 records · Page 7Linked to original sources
PubMed1991

Management of first episode psychotic illness in Afro-Caribbean patients.

We studied retrospectively a consecutive series of 40 Afro-Caribbean patients and compared them with 40 non-Caribbean patients matched for age, sex, and diagnosis. There was no overall difference in initial or cumulative doses of neuroleptic medication in the early treatment of psychosis. However, a small subgroup of Afro-Caribbean patients received higher peak dosages. Clearly recorded episodes of behavioural disturbances were more frequent in Afro-Caribbean patients generally. They were more likely to be admitted compulsorily, discharged earlier, and prescribed depot medication.

Acculturation↗
PubMed1991

Changes in the administrative incidence of schizophrenia.

First-admission rates to psychiatric hospitals, and data from certain psychiatric case registers suggest that there may have been a substantial decline in the administrative incidence of schizophrenia in recent years. However, data from the Nottingham case register show that rates for first-onset schizophrenia remained stable between 1975 and 1987. It is suggested that variations in trends between different parts of the UK may be partly explained by differences in the proportion of migrants and their children in the population at risk.

Adolescent↗
PubMed1990

Searching for the causes of schizophrenia: the role of migrant studies.

There have been consistent reports in the literature of increased rates of hospital admissions for schizophrenia among Afro-Caribbean (West Indian) migrants to England. Recent evidence for even higher rates in the British-born second generation is reviewed, together with the methodological limitations of such studies. It is concluded that there is probably an epidemic of schizophrenia and related psychoses in this group of migrants although further prospective and longitudinal studies are required. The findings point to the potentially important role of migrant studies in determining environmental risk factors for schizophrenia.

Acculturation↗
PubMed1990

Helicobacter pylori infection treated with a tripotassium dicitrato bismuthate and metronidazole combination.

Seventy-two patients with H. pylori infection in their antral mucosa took part in the study. Forty-three received metronidazole 400 mg t.d.s. for two weeks, plus De-Nol tabs 2 b.d. for four weeks, and the remaining 29 patients received metronidazole 400 mg t.d.s. for two weeks plus De-Nol liquid 5 ml q.d.s. for four weeks. Seven of 57 H. pylori isolates were found to have pre-treatment metronidazole resistance. Success, in terms of eradication of H. pylori, was assessed using a one-month post-treatment 14C urea breath test. Successful eradication of H. pylori was achieved in 72% and 79%, respectively, of the metronidazole/De-Nol tablet and metronidazole/De-Nol liquid groups. These figures increased to 87% and 84%, respectively, if the patients whose organisms were known to be metronidazole-sensitive were considered in isolation. H. pylori was successfully eradicated in only one of seven patients with a metronidazole-resistant organism.

Aged↗
PubMed1990

Evaluation of C. reactive protein values in neonatal sepsis.

C. reactive protein (CRP) estimations were performed prospectively on 30 consecutive admissions of very low birth weight infants to a Regional neonatal intensive care unit. The samples were analysed by a recently described, rapid intralipid agglutination assay and by a reference turbidimetric technique. Two hundred and ninety samples were assayed by both techniques. The intralipid agglutination was positive on two occasions when the reference method found normal levels. No false negative reactions occurred. Bacterial micro-organisms were isolated on 32 occasions but 19 of the organisms were considered to represent bacterial colonisation or contamination. The CRP remained negative in 17 cases. There were 13 episodes of clinical deterioration associated with positive bacterial cultures. In each of the six infants with severe systemic infections (septicaemia (4), meningitis (1), and osteomyelitis (1)), the levels were raised. In five of these infants the CRP was elevated before, or at the time of, the clinical deterioration. The CRP remained normal during seven (54%) of the culture positive events. We believe that the CRP estimations provide additional information in the evaluation of the infant with suspected sepsis. Serial measurements are helpful in distinguishing bacterial contamination from invasive infection but are not helpful in predicting infection during the pre-clinical phase. The intralipid agglutination technique is a rapid and reliable test and could be performed on the neonatal unit outside normal laboratory hours.

Acute-Phase Reaction↗
PubMed1989

Severe mental disorder in Afro-Caribbean patients: some social, demographic and service factors.

Forty-two consecutively identified Afro-Caribbean patients with a first episode of psychosis were compared with a similar group of non-Caribbean patients. A number of differences emerged, although the same proportion of patients in each group had symptoms for 6 months or more prior to psychiatric contact. Afro-Caribbean patients showed greater delay in seeking help, more 'disturbance' later in the course of their illness and were more likely to be admitted compulsorily. The social geography of the two groups suggests that the high rates of schizophrenia and related psychoses that we previously reported cannot be explained simply by differences in area of residence at the time of presentation.

Adult↗
PubMed1988

A prospective study of severe mental disorder in Afro-Caribbean patients.

Several previous studies have reported increased rates of schizophrenia among Afro-Caribbean immigrants, although doubt has been cast upon the value of case-note diagnoses and retrospective case-finding. A prospective study was therefore undertaken, including all patients of Afro-Caribbean ethnic origin with a first onset psychosis presenting to the psychiatric services from a defined catchment area. Utilizing several diagnostic classifications, rates for schizophrenia were found to be substantially increased in the Afro-Caribbean community, and especially in the 'second generation' British born. Mode of onset and symptom profiles of psychoses suggest that atypical syndromes, and by implication 'misdiagnoses', do not account for reported higher rates of schizophrenic illness in these patients.

Adolescent↗
PubMed1988

Host defence mechanisms in the bladder. II. Disruption of the layer of mucus.

The urinary bladder wall is lined by a layer of mucus which is believed to provide an important barrier to bacterial invasion of the urinary tract. Abnormal function of this protective layer could therefore be a factor predisposing the host to urinary tract infection (UTI). This study investigated the contribution of the bladder mucus to host defence in both acute and chronic lower UTI, using a non-obstructive animal model of infection which reproduces many features of the disease in man. The ultrastructural appearance of the infected bladder mucosa was assessed in tissue in which both the layer of mucus and bacterial glycocalyces were stabilized prior to examination by scanning and transmission electron microscopy. The protective role of the mucus layer was determined by disrupting the layer immediately prior to bacterial challenge. Both ultrastructural and bacteriological analyses have shown that infection was increased in those animals where the mucus barrier was disrupted.

Animals↗
PubMed1988

Host defence mechanisms in the bladder. I. Role of mechanical factors.

This study evaluated the contribution of host defence mechanisms to bacterial clearance from the urinary bladder using an animal model in which rats were infected with Escherichia coli. Factors studied included the effect of hydration status, induced ultrastructural changes to the surface of the bladder mucosa, and the relevance of bacterial replication. Clearance was divided into two phases, primary (0-4 h), and secondary (4-24 h). Ninety-nine per cent of Escherichia coli 075 was cleared during the primary phase from normal, dehydrated and polyuric animals and 93% from anuric animals. Clearance was shown to be dependent on the presence of viable tissue. Bacterial numbers continued to decrease during the secondary phase in normal and dehydrated animals but increased in polyuric and anuric groups. No such rise occurred when rats were inoculated with Escherichia coli E/2/64, a non-replicating mutant. Evidence of ultrastructural changes to the bladder associated with impaired antibacterial properties was found in polyuric and anuric animals. Clearance of particulate matter (killed Candida albicans) however was unaffected by mucus disruption. The study has shown that the clearance of microorganisms from the bladder was unrelated to the voided volume, but is closely associated with the antibacterial activity of the mucosal surface.

Animals↗
PubMed1988

Human lymphocyte and monocyte lysis of tumor cells mediated by a mouse/human IgG1 chimeric monoclonal antibody.

The mouse monoclonal antibody 17-1A (gamma 2a, kappa) recognizes a tumor-associated antigen expressed on human gastrointestinal malignancies and has been used in Phase I and II clinical trials. Chimeric genetic constructs have been produced using 17-1A variable region genes (VL and VH) and the constant region genes for human kappa light chains and gamma 1 heavy chains (C kappa and gamma 1). The chimeric gene constructs were transfected into mouse myeloma cells for antibody production. The secreted mouse/human chimeric antibody contains the antigen-binding domain of 17-1A and the human (gamma 1, kappa) constant regions. Native mouse 17-1A and the chimeric antibody (chIgG1) were analyzed for binding to two human colon cancer cell lines and for the mediation of cancer cell line antibody-dependent cellular cytotoxicity by normal human peripheral blood lymphocytes and monocytes in 4 h 51Cr-release assays. The 17-1A and chIgG1 gave similar results in these in vitro biologic assays. This study demonstrates the feasibility of using mouse/human chimeric antibodies in human therapeutic applications.

Animals↗
PubMed1987

Serum IgG subclasses in patients with an increased susceptibility to respiratory tract infections.

Serum IgG subclass concentrations were assayed in 45 patients with chronic respiratory tract infections and 16 patients with recurrent acute respiratory tract infections. Eleven of these 61 patients, all but one with recurrent acute infections, were IgA-deficient but the remainder had normal or high serum immunoglobulin concentrations. Only 4% of patients with chronic infections were IgG2-deficient. The prevalence of IgG2 deficiency amongst patients with recurrent acute infections was greater (31%), but in most cases this appeared to be due to an association with IgA deficiency. Owing to the limits of assay sensitivity it was not possible to determine whether any patient was IgG4-deficient, but the number of sera with undetectable IgG4 was greater in patients with recurrent acute infections than in controls (37.5% vs 10%, p less than 0.01), although such patients were mainly those with IgA and IgG2 deficiency. None of the patients had IgG1 or IgG3 deficiency; in fact IgG3 concentrations were higher than those of controls in both groups of patients (p less than 0.001) and IgG1 concentrations were higher than those of controls in patients with recurrent infections (p less than 0.01). Thus, unequivocal IgG subclass deficiency is uncommon in non-IgA-deficient patients, but those with IgG2 deficiency may have an immune defect requiring further investigation.

Adult↗
PubMed1986

The effect of metabolic acidosis on the synthesis and turnover of rat renal phosphate-dependent glutaminase.

Regulation of the mitochondrial phosphate-dependent glutaminase activity is an essential component in the control of renal ammoniagenesis. Alterations in acid-base balance significantly affect the amount of the glutaminase that is present in rat kidney, but not in brain or small intestine. The relative rates of glutaminase synthesis were determined by comparing the amount of [35S]methionine incorporated into specific immunoprecipitates with that incorporated into total protein. In a normal animal, the rate of glutaminase synthesis constitutes 0.04% of the total protein synthesis. After 7 days of metabolic acidosis, the renal glutaminase activity is increased to a value that is 5-fold greater than normal. During onset of acidosis, the relative rate of synthesis increases more rapidly than the appearance of increased glutaminase activity. The increased rate of synthesis reaches a plateau within 5 days at a value that is 5.3-fold greater than normal. Recovery from chronic acidosis causes a rapid decrease in the relative rate of glutaminase synthesis, but a gradual decrease in glutaminase activity. The former returns to normal within 2 days, whereas the latter requires 11 days. The apparent half-time for glutaminase degradation was found to be 5.1 days and 4.7 days for normal and acidotic rats respectively. These results indicate that the increase in renal glutaminase activity associated with metabolic acidosis is due primarily to an increase in its rate of synthesis. From the decrease in activity that occurs upon recovery from acidosis, the true half-life for the glutaminase was estimated to be 3 days.

Acidosis↗
PubMed1986

Progressive loss of the macrophage respiratory burst in oxygen toxicity.

The respiratory burst of rat alveolar macrophages stimulated by a variety of agents declines as a function of time of exposure to hyperoxia. Previous studies have evaluated this effect in terms of the stimulated O(2) production of a population of cells. The present study was designed to determine whether this decline is due to a "turning off" of the respiratory burst activity of some cells within the alveolar macrophage population or a general suppression of the activity of all cells. The phorbol myristate acetate (PMA) initiated respiratory burst of individual rat alveolar macrophages was monitored using the reaction of nitroblue tetrazolium (NBT), which results in the formation of a precipitate on active cells. The formazan staining was evaluated using black and white photographs of the cells and comparison to a scale constructed from photographed cells of four differing intensities of staining. Frequency distributions indicated that when the respiratory burst capability in the population of alveolar macrophages is impaired approximately 50% by oxygen exposure and/or culture in plastic vessels with artificial media, there is a gradual shift in NBT reduction rather than an "all or nothing" mechanism, in which the distribution would have reflected a shift from darkly stained cells to the very lessened or negligible staining observed at the end stage of oxygen toxicity.

Animals↗