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Biomedical subjects

A Hall

Publications and source records attributed to A Hall.

At least 433 records · Page 24Linked to original sources
PubMed1981

Taenia saginata (Cestoda) in western Kenya: the reliability of faecal examinations in diagnosis.

The prevalence of Taenia saginata (Cestoda) among 146 predominantly Pokot tribesmen in western Kenya was studied in an attempt to assess the reliability of detecting infections by faecal examinations. firstly, a single faecal sample was microscopically examined after being processed by a standard ether sedimentation technique. Secondly, all subjects were treated with niclosamide and a purgative and the tapeworms were recovered. In this way the efficiency of diagnosing infections by faecal examinations was estimated. T. saginata eggs were found in the faeces of 68% of the men who were eventually found to be infected. Information was collected by interview from all subjects about whether they were or ever had been infected with tapeworms and about the form of treatment previously sought or taken. Eleven out of 25 men were apparently unaware of their tapeworm infections while no evidence of infection was found among 10 of the 24 reportedly infected men. A change in the pattern of treatment for tapeworms was reported which may have resulted in a recent decline in the prevalence of infection.

Adult↗
PubMed1981

Target cell specificity of two species of human interferon-alpha produced in Escherichia coli and of hybrid molecules derived from them.

Plasmids containing cDNAs for human interferon (IfN) alpha-1, IFN alpha-2, and several hybrids of the two cDNAs, all joined identically to an Escherichia coli lac promoter fragment gave rise, in E. coli, to fused interferons (fIFNs) that had very different target-cell specificities. fIFN alpha-1 had a lower specific activity on human WISH cells than on bovine MDBK cells, while fIFN alpha-2 showed the opposite behavior. fIFN hybrids with the NH2-proximal half of fIFN alpha-2 behaved qualitatively like fIFN alpha-1, and those with the NH2-proximal half of fIFN alpha-2, behaved like fIFN alpha-2. On mouse L929 cells, fIFN alpha-2 was almost inactive, while fIFN alpha-1 showed relatively high activity. In this case, the fIFN hybrids with the COOH-proximal half of IFN alpha-1 showed activity on mouse cells, while the reciprocal hybrid did not. In many cases, the activity spectrum of the hybrids was very different from that of either parent. We propose that the IFN molecule has either two binding sites or two regions constituting the binding site, one in the COOH- and the other in the NH2-proximal half. The experimental findings can be accounted for if the fits of the two sites to their receptor counterparts on different cell lines are independent of one another.

Animals↗
PubMed1981

Intravenous carotid arteriography using line-scanned digital radiography.

Digital subtraction and an experimental system for line-scanned radiography were used to image the bifurcations of the carotid arteries. The subtracted images were obtained before and after injections of contrast media. The anatomy of the extracranial carotid arteries was demonstrated in most patients, and verified by selective catheter arteriograms. Unsuccessful studies were attributed to improper timing while obtaining the images, and to venous occlusion. Artifacts produced by motion limit the temporal subtraction method.

Angiography↗
PubMed1980

Effect of interferon-alpha 1 from E. coli on some cell functions.

Interferon-alpha 1 from Escherichia coli transformed with a hybrid plasmid containing a human leukocyte complementary DNA insert, induces resistance to virus in appropriate target cells. It also shares the following properties with natural leukocyte interferon (IFN). (i) It enhances natural killing activity of human lymphocytes, (ii) it enhances antibody-dependent cell-mediated cytotoxicity, (iii) it suppresses antigen- and mitogen-induced leukocyte migration inhibition, (iv) it inhibits growth of IFN-sensitive Burkitt lymphoma cells. Since these activities are exhibited by a cloned protein species, they are due to IFN itself and not to other human proteins.

Antibody-Dependent Cell Cytotoxicity↗
PubMed1980

Synthesis in E. coli of a polypeptide with human leukocyte interferon activity.

Double-stranded cDNA prepared from the 12S fraction of poly(A) RNA from interferon (IF)-producing human leukocytes was cloned in Escherichia coli using the pBR322 vector. One of the resulting clones had a 910-base pair insert which could hybridise to IF mRNA and was responsible for the production of a polypeptide with biological IF activity. Up to 10,000 units IF activity per g of cells was obtained from some clones.

Base Sequence↗
PubMed1980

Comparisons of several biological and physicochemical properties of human leukocyte interferons produced my human leukocytes and by E. coli.

Human interferon (IFN) prepared from virus-induced human leukocyte suspensions (leukocyte-derived interferon) was compared to the IFN extracted from Escherichia coli harboring a human interferon-alpha cDNA hybrid plasmid (Hif-SN35-AH-L6). E coli-derived IFN was 20 to 50 times more active than leukocyte-derived IFN on heterologous bovine, feline, murine and guinea pig cells, relative to the activity on human cells. After partial purification by affinity chromatography on an anti-human lymphoblastoid IFN antibody column, the IFN was analyzed by SDS-polyacrylamide gel electrophoresis. While leukocyte-derived IFN gave a heterogeneous pattern with major peaks of activity of 24000 and 19000 daltons, E. coli-derived IFN gave a heterogeneous peak of activity at about 17-18000 daltons. The leading edge of leukocyte-derived IFN in SDS-polyacrylamide gels was significantly more active on bovine cells than on human cells and coincided in mobility with E. coli-derived IFN, which was also much more active on bone than on human cells. After reduction with mercaptoethanol in SDS, the E. coli-derived IFN lost no activity, whereas the leukocyte-derived IFN lost about 90% of its activity. After reduction, E. coli-derived IFN migrated in SDS-polyacrylamide gels as a single peak at 24000 daltons, as did the residual activity of reduced leukocyte-derived interferon. Out data suggest that the interferon produced by the E. coli harboring the clone Hif-SN35-AH-L6 is analogous in size and cross-species activity to one of the molecular species of leukocyte-derived interferon.

Chromatography, Affinity↗
PubMed1979

An evaluation of Re/coagulan for blood center tests.

Re/coagulan was compared to the standard calcium chloride (CaCl2) method for effectiveness of recalcification of plasma and whole blood. The time required for clot formation was determined. The effect of Re/coagulan on the specificity of hepatitis tests, direct antiglobulin tests, indirect antiglobulin tests, and agglutination tests were investigated. Hepatitis testing was performed on untreated serum and Re/coagulan-treated ethylenediamine tetraacetic acid (EDTA) plasmas by radioimmunoassay, reversed passive latex agglutination, and reversed passive hemagglutination methods. Direct antiglobulin tests were performed on untreated, CaCl2 treated, and Re/coagulan treated EDTA, acid-citrate-dextrose (ACD), and citrate-phosphate-dextrose (CPD) samples of whole blood. Red cell antibody specificity and titer were determined before and after clot formation by both the CaCl2 and Re/coagulan methods. Examples of agglutinating and sensitizing antibodies were tested. Antibodies directed against antigens in the Rh, Kell, MNS, Lewis, P, Kidd, Duffy, and Lutheran blood groups systems were investigated. Re/coaglulan didnot have a detrimental effect on the tests performed and compared favorably to the standard recalcification method.

Agglutination Tests↗
PubMed1978

Family structure and relationships of 50 female anorexia nervosa patients.

Family features of the first 50 anorexia nervosa patients referred to a psychiatrist from a defined geographic area are documented. Information about the families was obtained from personal interviews with the parents during the course of the patients' treatment. High socio-economic class, absence of non-white population, older age of parents, instability factors in the parents' backgrounds and high incidence of both physical and psychiatric illness in the parents suggest multiple factors may be aetiological. Possible pathogenic factors are equally distributed between mothers and fathers.

Adolescent↗
PubMed1977

The psychotherapy of character disorder.

Patients suffering from character disorder are often rejected as unsuitable for psychotherapy. Those with anxiety and depression often seek help, and should be assessed for their potential to be helped by a carefully structured long term psychotherapeutic relationship controlled by the therapist to reduce acting out behaviour. The therapist acts throughout as a model for the patient. As the patient develops basic trust in the therapist, identification develops and a major sustained improvement can occur. The therapy described is current-behaviour orientated and the importance of clear, unambiguous communication, particularly verbal communications, is stressed. The principles of therapy are applicable to all contacts with character-disordered patients. Briefly described is the long term therapy of two patients with hysterical personality disorders and acting-out behaviour, as examples of one type of the wide variety of character disorders that can be treated, and where the nine year follow up was adequate to ensure that improvement was sustained.

Adult↗
PubMed1976

Acute appendicitis in the geriatric patient.

Fifty patients over 60 with proven acute appendictis are analyzed with regards to the preoperative clinical picture, diagnosis, operative findings and management, and the role of associated medical diseases.

Acute Disease↗
PubMed1975

Clinical observations and their relationship to laboratory findings in the haemophilias.

Continuous observations in shcool terms have been made on the frequency of spontaneous bleeding episodes in a group of adolescent boys suffereing from haemophilia (39 cases), Christmas disease (9 cases), and von Willebrand's disease (2 cases). The observations suggest that in haemophilia other factors, besides the deficient factor VIII, affect the bleeding frequency. In the two boys with von Willebrand's disease, the lower level of factor VIII was associated with the milder symptoms; whereas in boys with Christmas disease clinical severity and laboratory results seemed to be correlated.

Adolescent↗
PubMed1975

The uncatalyzed rates of enolization of dihydroxyacetone phoshate and of glyceraldehyde 3-phosphate in neutral aqueous solution. The quantitative assessment of the effectiveness of an enzyme catalyst.

By a combination of methods involving enzyme-catalyzed reactions and classical iodination techniques it has been possible to obtain all the relevant rate constants for the uncatalyzed interconversion of dihydroxyacetone phosphate and D-glyceraldehyde 3-phosphate via their common enediol intermediate. These rate constants are compared with those for the individual steps of the triosephosphate isomerase catalyzed reaction, and a quantitative picture of the effectiveness of the enzyme as a catalyst has been delineated. It is apparent that the enzyme increases the enolization rate of dihydroxyacetone phosphate by a factor of more than 10(9) over that of the uncatalyzed reaction.

Carbohydrate Epimerases↗