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Biomedical subjects

C Harrison

Publications and source records attributed to C Harrison.

At least 55 records · Page 3Linked to original sources
PubMed1991

Perioperative nursing on the Amazon River. An experience that made a difference.

We held a conference at the end of the team's visit. We concluded that there was a continuum of learning in both directions from both countries. Some of the problems and frustrations in medicine are the same worldwide. Leaving the US medical system to work in a remote area is a fascinating and exciting experience. Clean water, electricity, transportation, and food are not taken for granted in this area of the world. The next decade in an area like this holds many different plans, hopes, and projects. Nothing can be taken for granted. All that has been developed could be lost tomorrow. What we do makes a difference, whether it is in the jungles of Brazil or an OR in the United States. To see the health of the general population so markedly improved from our previous visit emphasized that point. Your skills as an OR nurse can be translated to other countries. An instrument may have a different name, but the use is the same. Operating room nursing on the Amazon River is the same, and it is different. You can and do make a difference to your patients each day. We found that the difference is less subtle in an area that has so little.

Brazil↗
PubMed1991

Extracellular organelles (prostasomes) are immunosuppressive components of human semen.

Numerous reports have ascribed immunosuppressive activity to human seminal plasma and there is growing agreement that much of this activity can be accounted for by the very high levels of E series prostaglandins present (up to 300 microM 19-hydroxy prostaglandin E). However not all suppressive activity is due to prostaglandin since several reports have appeared of high molecular weight active substances and we have found that stripped seminal plasma is still effective in inhibiting the mitogen-induced proliferation of lymphocytes. In this study such immunosuppressive activity has been separated by molecular size fractionation and the activity has been found to be particulate and corresponded to the previously reported prostasomes. These are trilaminar to multilaminar vesicles (150 nm diameter) which are secreted by the prostate. Pure preparations of prostasomes inhibited mitogen-induced lymphoproliferation in a dose-dependent manner with a concentration of prostasomes equivalent to 40% of that seen in seminal fluid giving 69% suppression of thymidine incorporation. The suppressive activity survived boiling and therefore was unlikely to be due to enzymatic action associated with these organelles. Interaction with the accessory cells, involved in full development of the lymphoproliferation induced by mitogen, was indicated and this possibility was supported by the demonstration of a direct effect of prostasomes on macrophage function using a mouse macrophage cell line. The prostasomes in semen may play a complementary role to the prostaglandins in neutralizing the immune defences of the female reproductive tract. This combination would allow the alloantigenic spermatozoa the best chance of achieving fertilization, but at the same time leave the recipient open to any infection present in the semen.

Analysis of Variance↗
PubMed1990

Functional studies of bone marrow haemopoietic and stromal cells in the myelodysplastic syndrome (MDS).

Long-term bone marrow culture (LTBMC) was used to investigate the proliferative behaviour of marrow cells from a spectrum of cases of the myelodysplastic syndrome (MDS), and the results compared with those obtained in the conventional short-term clonal assay. Two broad patterns of growth were revealed in LTBMC. In one group the incidence of haemopoietic progenitor cells steadily declined to abnormally low levels at 4 weeks, while in a second group they were maintained near normal levels for periods of up to 7 weeks. These growth patterns, which were not predictable from clonogenic assays on the marrow cells prior to LTBMC, or from the morphology of the bone marrow, may reflect the stage of evolution of the disease. Further studies of clonality are required to establish whether or not patients exhibiting the second pattern have a potentiality to harbour residual normal haemopoiesis. LTBMC was also used to study the function of MDS marrow stroma in terms of its ability to sustain the growth of normal haemopoietic progenitor cells. Although the phenotype of the cultured adherent cell layer, obtained from some patients, was atypical, no consistent functional defect of MDS stroma could be identified by studying the level of haemopoiesis reached by normal cells seeded into MDS stroma.

Adolescent↗
PubMed1990

Sex, drugs, and HIV infection in a New York City hospital outpatient population.

Persons attending outpatient clinics at Bellevue Hospital Center in Manhattan, New York City were invited to be tested for antibodies to human immunodeficiency virus (HIV). In pretest counseling, males were asked if they had injected nonprescription drugs or engaged in sex with other men since January 1, 1977; if so, they were asked not to participate and were referred elsewhere for testing. Face-to-face interviews and HIV testing were completed for 1,119 subjects with no prior indication of HIV seropositivity. Willingness to participate in the study was significantly greater among women than men and among younger than older persons. After exclusion of two subjects with indeterminate HIV serology, seroprevalence was 6.3% (70/1,117) overall, 7.1% (26/368) among men, and 5.9% (44/749) among women. HIV seropositivity among female i.v. drug users was 37% (27/74). Among heterosexuals without other HIV risk factors, estimated seroprevalences were 2.7% (25/924) overall, 3.3% (10/305) among males, and 2.4% (15/619) among females. Among heterosexual men, the data suggested associations of HIV seropositivity with sex with prostitutes and sex with numerous partners. Multiple logistic regression analysis indicated that significant predictors of HIV infection among women were a history of sexual contact with a male intravenous drug user, recent last use of intravenous drugs, and long duration of residence in New York City. Sexual intercourse with persons from AIDS risk groups was reported by 11% of men and 18% of women. The modal method of birth control reported by both men and women was "no method".

Adult↗
PubMed1990

The use of cultured bone marrow cells in autologous transplantation.

The feasibility of ex vivo purging with long-term bone marrow cultures (LTBMC) for autologous transplantation in leukemia has been established. The procedure has been applied to patients with acute myeloid leukemia (in relapse or remission) and recently in one patient with chronic myeloid leukemia. The results in first remission AML are very encouraging with 4 out of 6 patients well and apparently disease free greater than 1 to 4 years post autograft. In patients transplanted with active disease, remissions of 6 to 8 months duration were seen in two patients transplanted in florid relapse. In a CML patient with 87% of his bone marrow cells Ph1 positive, there was a marked decline of karyotypically abnormal cells in culture. Reinfusion of the cultured cells into the patient resulted in engraftment with exclusively Ph1 negative cells. The therapeutic implications of LTBMC purging require further evaluation.

Bone Marrow Cells↗
PubMed1989

Characterization of surface polypeptides on different life-cycle stages of Theileria annulata.

We describe the characterisation of polypeptides located on the surface of Theileria annulata sporozoites, macroschizonts, piroplasms and infected lymphoblastoid cells using surface iodination techniques. The sporozoite stage exhibited a complex profile of surface polypeptides. However, using data from experiments with defined monoclonal antibodies, the sporozoite surface appeared to be composed of several distinct groups of related polypeptides. Analysis of the macroschizont detected seven surface polypeptides, while eight polypeptides were identified for the piroplasm stage. On the basis of molecular weight comparisons, one of the surface polypeptides appeared to be common to the sporozoite, macroschizont and piroplasm. Stage cross-reactive monoclonals failed to immunoprecipitate a surface-radiolabelled polypeptide, and this prohibited the characterisation of a stage common surface antigen. From the surface labelling studies of Theileria-infected and uninfected lymphoblastoid cell lines, we concluded that infection results in major changes at the surface of the host cell, including both the appearance and loss of specific polypeptides. By employing monoclonal antibodies which detect infection-associated determinants, and a polyclonal antiserum raised against a glycoprotein fraction of an infected cell lysate, surface-labelled polypeptides were specifically immunoprecipitated from extracts of infected cells. The polypeptide detected by monoclonal antibody 4H5 was characterised as an infection-associated glycoprotein which varies in molecular mass when immunoprecipitated from different infected cell lines. The identification of infection-associated glycoproteins on the surface of the lymphoblastoid cell suggests that these molecules may be recognised by the cytotoxic T cells of immune animals.

Animals↗
PubMed1989

Red cell ferritin and iron overload in heterozygous beta-thalassemia.

Red cell ferritin was evaluated in 101 individuals with heterozygous beta-thalassemia to determine its clinical utility as an index for iron deficiency or overload in these subjects. The mean red cell ferritin for the total population was elevated threefold and showed a significant correlation with transferrin saturation, plasma ferritin, and HbA2 levels. Five of six subjects with reduced red cell ferritin had associated iron deficiency; a further five had iron deficiency and normal red cell ferritin. Normal red cell ferritin occurred in 51 subjects, and 44 had increased values. In the elevated red cell ferritin group, 21 individuals had associated normal plasma ferritin, and 23 had increased plasma ferritin. Only in the latter group was red cell ferritin significantly correlated with transferrin saturation and plasma ferritin. Ten individuals had a red cell ferritin greater than or equal to 150 attogram/cell, and liver biopsy performed in four showed grades II to IV iron overload. A clinical feature of subjects with both increased red cell and plasma ferritin levels was a high incidence of inappropriate iron administration. These findings suggest that red cell ferritin, particularly when combined with plasma ferritin, is a useful parameter for determining potential iron overload in individuals with heterozygous beta-thalassemia.

Adolescent↗
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↗