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Biomedical subjects

C Harrison

Publications and source records attributed to C Harrison.

At least 91 records · Page 5Linked to original sources
PubMed1989

Iron-deficiency anaemia and its response to oral iron: report of a study in rural Gambian children treated at home by their mothers.

Haematological and iron parameters, measured in 907 children aged from 6 months to 5 years in rural Gambia at the start of the rainy season, differed from those in American reference populations as follows: mean haemoglobin levels were much lower at ages 1 and 2 years and mean levels of mean corpuscular volume (MCV) were lower at all ages (at age 1 year mean haemoglobin was 11.2 g/dl and mean MCV 68.2 fl); in a sample of 249 children randomly selected from the whole study population, mean serum iron levels were similar but mean transferrin saturation and mean serum ferritin levels were lower, especially at ages 1-3 years (at age 1 year mean serum iron was 11.1 mumol/l, mean transferrin saturation 16.9%, and geometric mean serum ferritin 8.8 ng/ml. A total of 213 children (23%) whose haemoglobin and mean corpuscular volume were both less than the 3rd percentile of the reference population received oral iron or placebo from their mothers during the rainy season when malaria transmission is maximal. Mean levels of haemoglobin, mean corpuscular volume, serum iron, transferrin saturation and serum ferritin rose in the iron-treated group and fell in the placebo group at all ages, except under 1 year for serum ferritin, to produce significant differences between the groups by the end of the study. Total iron-binding capacity showed no significant changes during the study. We concluded that oral iron given by the mother during the rainy season can be used to treat iron-deficiency anaemia in Gambian children who would otherwise become more anaemic.

Administration, Oral↗
PubMed1989

The effects on malaria of treatment of iron-deficiency anaemia with oral iron in Gambian children.

In order to determine whether giving iron to iron-deficient children increases their susceptibility to malaria, 213 Gambian children aged between 6 months and 5 years with iron-deficiency anaemia were randomized to receive either oral iron or placebo during the rainy season when malaria transmission is maximal. Haematological and iron measurements improved significantly in the group given iron. Regular morbidity surveys showed that fever associated with parasitaemia occurred more frequently in the iron-treated group than in the placebo group. This difference was not significant for all parasitaemias grouped together, but became significant and progressively larger for parasitaemias of ten or more positive fields per 100 high power fields (P less than 0.025), and for parasitaemias of 50 or more positive fields per 100 high power fields (P less than 0.01). Three children in the iron-treated group but none in the placebo group had more than one episode of fever and parasitaemia. Splenomegaly rates rose appreciably during the study in both groups, but in children at age 2 years the splenomegaly rate at the end of the study was significantly greater in the iron-treated group. We concluded that there is a significantly increased risk of fever associated with severe malarial parasitaemia for children with iron-deficiency anaemia given iron during the season of maximal malaria transmission in this part of The Gambia.

Administration, Oral↗
PubMed1989

Community reintegration of SCI persons: problems and perceptions.

A survey of 222 SCI patients treated by the Southeastern Michigan Spinal Cord Injury System was conducted to explore some key issues involving community reintegration problems. These patients had been discharged from the rehabilitation facility an average of 18 months. The 62 respondents (28%) did not differ from nonrespondents on demographic and health status variables and were considered representative of the total patient population. Important findings included the following: 1) 30% were noncompliant with prescribed medication, 2) 25% had not received all equipment prescribed during initial rehabilitation, 3) 45% indicated their current residence was not completely accessible, 4) 73% were dependent on others for transportation, 5) 8% were currently working, compared to 39% employed prior to injury 6) 47% indicated transportation problems as the main obstacle to their adjustment to SCI. The problems identified prevented the SCI patients from increasing their presence in the community, thereby preventing them from exposing obstacles and improving the opportunities available to them.

Activities of Daily Living↗
PubMed1988

Treatment failure in Trichomonas vaginalis infections in females. I. Concentrations of metronidazole in plasma and vaginal content during normal and high dosage.

Concurrent estimation by high pressure liquid chromatography (HPLC) of the concentrations of metronidazole in plasma and vaginal content in 12 patients with infections due to Trichomonas vaginalis who did not respond to normal and high-dose treatment has shown that the two levels are closely related to each other and to the dose. Individual idiosyncrasies in absorption of drug from the gut lumen or in its transfer into the vaginal content are unlikely to be the cause of treatment failure.

Adolescent↗
PubMed1988

Treatment failure in Trichomonas vaginalis infections in females. II. In-vitro estimation of the sensitivity of the organism to metronidazole.

We have developed a standard procedure to measure the susceptibility of Trichomonas vaginalis to metronidazole in vitro, by controlling the state of oxygenation of the test cultures, the size of the inocula in terms of infectivity, and providing multiple tests at each drug concentration. Estimates were made of the in-vitro sensitivity to metronidazole of T. vaginalis isolated from 11 randomly selected patients, all, except for three defaulters, known to have been treated successfully, and from six 'treatment failure' patients. Stocks isolated from 'successfully treated' patients, were all highly sensitive to metronidazole. Eighteen stocks isolated from the 'treatment failure' patients fell into two groups: (a) those clearly separable from sensitive stocks, with ED50 values (the concentration of drug at which growth is prevented in 50% of test wells) in N2 of up to 0.51 mg/l and 3.5 to 11 mg/l in N2/1%O2; (b) those giving intermediate ED50 values of up to 0.20 mg/l in N2 and 0.7 to 1.8 mg/l in N2/1%O2. The current procedure demonstrates clearly that repeated treatment failure in patients without other complication is associated with enhanced resistance to metronidazole of T. vaginalis, and it may discriminate between T. vaginalis infections that are likely to respond to higher dosage and those that are not.

Adult↗
PubMed1988

An investigation of the effects of lofepramine, nomifensine, amitriptyline and placebo on aspects of memory and psychomotor performance related to car driving.

Ten healthy, female volunteers took part in a double-blind, placebo-controlled study to investigate the effects of lofepramine 70 mg, lofepramine 140 mg, nomifensine 100 mg, amitriptyline 50 mg and placebo on psychomotor performance related to driving. One subject failed to complete the study for reasons unrelated to the medications. Each subject received each of the treatments in random order at weekly intervals and was then assessed for psychomotor performance, sedation and quality of sleep. Amitriptyline 50 mg served as a positive control producing results consistent with its known sedative properties. In contrast, lofepramine 70 mg and 140 mg and nomifensine 100 mg were generally free from any significant effect on psychomotor performance.

Adult↗
PubMed1987

Replacement of potassium chloride by potassium glutamate dramatically enhances protein-DNA interactions in vitro.

Although protein-nucleic acid interactions exhibit dramatic dependences on both ion concentration and type in vitro, large variations in intracellular ion concentrations can occur in Escherichia coli and other organisms without apparent effects on gene expression in vivo. E. coli accumulates K+ and glutamate as cytoplasmic osmolytes. The cytoplasmic K+ concentration in E. coli varies from less than 0.2 to greater than 0.9 m as a function of external osmolarity; corresponding cytoplasmic glutamate concentrations range from less than 0.03 to greater than 0.25 m. Only low levels of chloride occur in the cytoplasm of E. coli at all osmotic conditions. Since most in vitro studies have been performed in chloride salts, whereas glutamate is the more relevant physiological anion, we have measured the effects of the substitution of potassium glutamate (KGlu) for KCl on the kinetics and equilibria of a variety of site-specific protein-DNA interactions in vitro. Both the interaction of E. coli RNA polymerase with two phage lambda promoters and the interactions of various restriction enzymes with their DNA cleavage sites are enhanced by this substitution. Using the abortive initiation assay, we find a greater than 30-fold increase in the second-order rate constant for open complex formation at the lambda PR promoter and a 10-fold increase at the lambda PR' promoter, when KGlu is substituted for KCl. Replacement of KCl by KGlu does not affect the strong salt dependences of these interactions; increasing either KCl or KGlu concentrations decreases both reaction rates and extents. Substitution of glutamate for chloride does, however, shift the range of salt concentrations over which these interactions are observable to higher K+ concentrations.(ABSTRACT TRUNCATED AT 250 WORDS)

DNA Restriction Enzymes↗
PubMed1987

Expression of human CD antigens, including CD1 and CD25, by human x mouse interlineage leukaemia hybrids.

The expression of human cell-membrane antigens by hybrid cell lines derived by fusing a human B-ALL and mouse BW 5147 T-lymphoma cells has been studied. Using monoclonal antibodies (mAb), the phenotypes of 19 of the 24 hybrids which grew 11-44 days post-fusion have been analysed by indirect membrane immunofluorescence (IF). These uncloned hybrid cells were assayed early after outgrowth, prior to extensive human chromosome and antigen loss. Nonetheless, cytogenetic analysis showed that all hybrids contained variable numbers of human chromosomes. Phenotypic analysis showed that the hybrids could be grouped as follows: a high frequency expressing CD25 (IL-2 receptor), human T200, HLA class I alpha and beta 2microglobulin, and reacting with the mAb H207 and 12E7; an intermediate frequency expressing CD1 and CD2; and a low frequency expressing CD3, CD4, CD5, CD7, CD8 and CD9. This pattern of antigen expression resembled the frequency of these cells in the human B-ALL parent line. Cell sorting was used to immunoselect hybrids expressing CD1 and CD2, but CD1 expression was unstable during subsequent culture.

Animals↗
PubMed1986

Chronic epileptogenesis induced by kindling of the entorhinal cortex: the role of the dentate gyrus.

The role of the dentate gyrus (DG) in the development and maintenance of kindling induced by periodic electrical stimulation of the entorhinal cortex (EC) was evaluated in rats. Colchicine, a selective neurotoxin for granule cells of the DG, was injected into the DG: prior to kindling and after the development of kindling. Prior destruction of the DG delayed the development of afterdischarge (AD) induced by EC stimulation, but kindling proceeded at normal rates after the first AD was induced. Destruction of the DG after kindling did not abolish the kindled seizures. Thus, the DG was not required for either the development or maintenance of kindling by EC stimulation, but an intact perforant path input from the EC to DG facilitated the emergence of epileptogenesis by kindling of the EC. The results suggest that kindling develops and is maintained in a network of multiple pathways which are related to the site of stimulation. The DG appears to be the site of a temporally specific alteration which facilitates the development of kindling by EC stimulation.

Animals↗
PubMed1986

Reconstitution of haemopoietic system with autologous marrow taken during relapse of acute myeloblastic leukaemia and grown in long-term culture.

In long-term cultures of bone marrow from a patient with acute myeloblastic leukaemia (AML) the leukaemic chromosome marker, which was present in a proportion of the marrow cells even during morphological remission, was not detectable after seven days of culture. After florid relapse of AML, large-scale bone marrow cultures were established while the patient received conditioning with cyclophosphamide and total body irradiation as for an allogeneic bone marrow transplant. Marrow cultured for ten days was reinfused and three and six months later the patient was in clinical remission with a normal karyotype.

Adolescent↗
PubMed1986

Philadelphia-positive metaphases in the marrow after bone marrow transplantation for chronic granulocytic leukemia.

A 28-year-old man with Ph-positive chronic granulocytic leukemia (CGL) was treated by high-dose chemoradiotherapy and transplantation of marrow cells harvested from his HLA-identical brother. One year after bone marrow transplantation (BMT) examination of his marrow showed a minority population of Ph-positive cells; their proportion subsequently fell such that 2 years after transplant analysis of marrow cells showed only cytogenetically normal cells. The patient remains clinically normal with a persisting mild lymphocytosis but without hematological evidence of leukemia. We cannot in this patient distinguish between persisting leukemia that later could no longer be recognized and relapse of leukemia that is now suppressed, perhaps only temporarily. This case emphasizes the need for caution in interpreting chromosomal finding after BMT for CGL.

Adult↗