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Biomedical subjects

J Perkin

Publications and source records attributed to J Perkin.

11 recordsLinked to original sources
PubMed1997

Failed treatment of Helicobacter pylori infection associated with resistance to clarithromycin.

BACKGROUND: Resistance of Helicobacter pylori to clarithromycin is uncommon. Initial studies have suggested that primary resistance has a significant adverse effect on bacteriological cure rates and acquired resistance develops frequently with failure of treatment following regimens containing clarithromycin. MATERIALS AND METHODS: H. pylori isolates were obtained from patients with duodenal ulcer treated with clarithromycin and omeprazole and examined for susceptibility to clarithromycin using the E-test method. A 13C urea breath test was used to confirm infection with H. pylori and successful treatment. RESULTS: H. pylori infection was successfully treated in 101 patients, all with susceptible isolates, and persisted in 30 patients of whom 4 had resistant isolates. Of 16 patients with bacteriological cure failure who had susceptible isolates pretreatment, 11 (68.8%) had resistant isolates post-treatment. CONCLUSIONS: This study confirms previous reports that acquired resistance of H. pylori to clarithromycin develops frequently (68.8-96%) in individuals with failed dual therapy regimens. Primary resistance, although uncommon (3%), was 100% predictive of treatment failure with the regimen used in this study. Effective treatment of H. pylori infection should help to prevent the development of resistance to clarithromycin.

Anti-Bacterial Agents↗
PubMed1988

Ethnicity and Food Stamp program participation: effect upon dietary intakes of low-income mothers served by a north Florida family practice center.

Ethnic differences in self-reported dietary intake between blacks and whites (participants and non-participants in the Food Stamp program) were studied in a group of 102 low-income mothers presenting themselves for treatment at an urban family practice center. The study population included 51 whites, of whom 21 were participants in the Food Stamp program, and 51 blacks, of whom 29 were Food Stamp program participants. The mean age of white and black mothers was approximately 29 years. Mean numbers of children per family were 2.1 for whites and 2.82 for blacks. Food and nutrient intake data were collected using a 24-hour recall and a food frequency questionnaire. Mean intakes of calcium, iron, riboflavin, and thiamin were found to be less than the RDAs for both groups. Whites additionally had mean intakes of vitamin A and niacin that fell below the RDAs. Blacks had significantly higher mean intakes of niacin and protein and a significantly higher 24-hour mean intake of soft drinks than whites. Being a member of the black race was positively associated with consumption of chicken, hot dogs, collard/mustard greens, and white rice. Being a member of the white race was positively associated with consumption of broccoli, potatoes, and whole wheat bread. Among participants in the Food Stamp program, mean intakes of protein, niacin, and soft drinks were significantly higher for blacks than for whites. This study suggests that ethnic differences in food preferences do exist but that those preferences do not translate into major differences in daily reported nutrient intakes.

Adult↗
PubMed1985

Some biochemical properties of higher plant tubulins.

Tubulin was isolated by a combination of affinity (ethyl N-phenylcarbamate-Sepharose) and ion exchange (DEAE-Sephacel) chromatography from mung bean and cultured carrot suspension cells. SDS-PAGE (Blose 1981) of mung bean tubulin has shown it to consist of two major subunits (MBT1 and MBT2) and a minor subunit (MBT3). Tubulin isolated from carrot cells was resolved into only two bands on SDS-PAGE (slow moving subunit was named CT1). However, the faster moving subunit on SDS-PAGE was resolved into two bands (CT2 and CT3) on SDS-4M urea-PAGE. On SDS-4M urea-PAGE, CT1 migrated faster than CT2, CT3. By contrast in SDS-4M urea-PAGE, mung bean tubulin remains unresolved. Mammalian tubulin could be resolved into alpha and beta-subunits in both electrophoretic systems. Monoclonal antibodies to mammalian alpha and beta-tubulin subunits (MCA-T alpha and MCA-T beta, respectively) and Western blot analysis clearly demonstrated a cross-reactivity of MCA-T alpha with MBT2, MBT3, CT2 and CT3, while MCA-T beta showed cross-reactivity with MBT1 and CT1. Although MBT2, MBT3, CT2 and CT3 are immunologically related to the alpha-subunit of mammalian tubulin, their migration on SDS-PAGE was reversed with respect to MBT1 or CT1, which were immunologically related to the beta-subunit of mammalian tubulin. Peptide mapping patterns also supported above the results.

Antibodies, Monoclonal↗
PubMed1984

The agglutination of human platelets by botrocetin: evidence that botrocetin and ristocetin act at different sites on the factor VIII molecule and platelet membrane.

Botrocetin caused a factor VIII (FVIII) dependent platelet agglutination which was associated with a reduction in the plasma levels of all FVIII parameters as a result of specific binding of FVIII to the platelets. The site of binding of FVIII to the platelet in response to ristocetin or botrocetin involves the glycoprotein I complex. This is suggested by the inability of chymotrypsin treated platelets or platelets from patients with the Bernard-Soulier syndrome to agglutinate in response to ristocetin. These platelets responded to botrocetin , but this was greatly reduced compared to normal. Crossed immunoelectrophoretic analysis indicated that in the presence of botrocetin most multimetric forms of FVIII bound to the platelet, whereas ristocetin caused binding of high and intermediate molecular weight forms. The antibiotic vancomycin inhibited platelet agglutination by ristocetin but had no effect on that caused by botrocetin . Assays of FVIII von Willebrand factor (VIII:vWf) using botrocetin compared well with those obtained using ristocetin in plasmas from normal individuals and from patients with classical von Willebrand disease (vWd). However, a patient with variant vWd demonstrated 100% botrocetin cofactor activity and 0% ristocetin cofactor activity. This suggested that the site of interaction on the FVIII molecule for botrocetin and ristocetin are different. Therefore the diagnosis of some von Willebrand variants cannot be excluded on the basis of a normal botrocetin cofactor assay.

Blood Platelets↗
PubMed1983

Evaluating a nutrition education program for pregnant teen-agers: cognitive vs. behavioral outcomes.

A manual-based program of nutrition education for pregnancy and lactation was developed. This program was evaluated in a classroom setting using two measures of effectiveness. A pretest and posttest format was used to assess cognitive outcomes and predietary and postdietary records were used to assess behavioral changes. The difference between cognitive test scores was significant. However, actual dietary improvements were slight and were within the range of normal intake variation. This study emphasizes the need to assess behavior in order to more fully evaluate educational effectiveness. Observations of the study also suggest the desirability of environmental support for the successful translation of classroom knowledge into appropriate behaviors.

Adolescent↗
PubMed1983

Coagulopathy of peritoneovenous shunts: studies on the pathogenic role of ascitic fluid collagen and value of antiplatelet therapy.

The role of ascitic fluid collagen in the pathogenesis of the coagulopathy that follows peritoneovenous shunting was examined. Collagen was partially purified from ascitic fluid and infused into rabbits. All animals developed changes in their haemostatic profile consistent with intravascular coagulation. Aspirin therapy, for five days before the collagen infusion, prevented these changes. Seven patients undergoing a total of eight peritoneovenous shunts for intractable ascites received antiplatelet therapy (aspirin and dipyridamole) in the immediate pre- and postoperative period. After six shunts no thrombocytopenia or prolongation of clotting times developed to suggest decompensated consumptive coagulopathy. Complicating factors may have contributed to the deterioration in haemostasis in the other two patients. There was no early shunt occlusion. The results support the hypothesis that ascitic fluid collagen is important in the pathogenesis of intravascular coagulation postascitic fluid infusion and indicate that antiplatelet drugs may be of value in preventing this complication.

Adult↗
PubMed1982

Variant von Willebrand's disease type B--revisited.

Results of investigations of the factor VIII (FVIII) of a patient with an unusual variant form of von Willebrand's disease (vWD) are presented. A two-peak crossed-immunoelectrophoresis (CIE) pattern was seen when fresh plasma was electrophoresed, but the CIE pattern became normal by incubating the plasma at 37 degree C for more than 72 hr. The two peaks on CIE were separated by cryoprecipitation: the slow-moving peak precipitating and the fast-moving forms of FVIII remaining in the cryosupernate. An additional protein band was seen on multimeric analysis of FVIII. The platelet-rich plasma (PRP) from this patient did not respond to ristocetin, but agglutinated normally in response to botrocetin. Multimeric and CIE analysis of the FVIII post agglutination and 125I-FVIII binding studies to normal formalin-fixed platelets indicated that this patient's FVIII interacted normally with botrocetin but failed to interact with ristocetin. These data strongly suggest that the sites on the FVIII molecule or the multimeric forms involved for ristocetin and botrocetin are different and that the ristocetin reaction is more closely aligned to the physiologic function of FVIII.

Animals↗
PubMed1981

Quantitation of binding of factor VIII antigen to concanavalin A.

This study establishes a convenient method for screening plasma samples for abnormalities of the carbohydrate content of the factor VIII (FVIII) molecule. A radioimmuno-electrophoretic technique has been developed to quantitate the percentage binding of FVIII-related antigen (VIII-Ag) to the lectin concanavalin A (Con A). Plasma samples were electrophoresed through a strip of agarose containing Con A into agarose containing a mixture of unlabelled anti-FVIII and 125I-anti-FVIII where precipitant lines formed, the height of which was dependent upon the degree of VIII-Ag binding to Con A in the first gel. Using this system reduced binding of VIII-Ag to Con A was found in the plasma of 12 patients with moderate classical von Willebrand's disease (vWd), while the Con A binding of six haemophilia A patients fell within the normal range. The VIII-Ag in normal cryoprecipitate showed increased % binding to Con A while the VIII-Ag remaining in the cryo-supernate demonstrated reduced Con A % binding.

Antigens↗