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Biomedical subjects

R Kretschmer

Publications and source records attributed to R Kretschmer.

At least 37 records · Page 2Linked to original sources
PubMed1996

Increased frequency of HLA-DR3 and complotype SCO1 in Mexican mestizo children with amoebic abscess of the liver.

The increase of HLA-DR3 and complotype SCO1 previously found in Mexican mestizo adults with E. histolytica amoebic abscess of the liver, was also found in Mexican mestizo children of either sex with the same disease, when compared to the healthy control population (adults and/or children) of the same ethnic and socioeconomic background. This HLA and complotype pattern was not found in Mexican Mestizo patients with amoebic rectocolitis. No linkage disequilibrium was found between these and the other MHC determinants tested in this survey. Thus, HLA-DR3 and SCO1 may constitute primary, independent risk factors, not for any kind of amoebic tissue invasion (i.e. amoebic rectocolitis), but specifically for amoebic liver abscess, irrespective of age or sex. The possibility of linkage disequilibrium with other factors (i.e. the TNF family) within or close to the MHC that were not tested in this study, is discussed. Children with amoebic liver abscess revealed a significant increase in HLA-DR5, and the absence of HLA-DR6 when compared to adults with amoebic liver abscess, suggesting that at least in this ethnic group these class II HLA traits may contribute to some of the peculiarities of pediatric amoebic liver abscess as opposed to the adult version of this disease. HLA-DR3, SCO1, but also HLA-DR5 and HLA-DR6 have all been associated with certain forms of immune-dysfunction, and may thus contribute to some of the clinical and immunological features of this parasitic disease.

Adolescent↗
PubMed1996

Alteration of cyclosporin-A pharmacokinetics after experimental spinal cord injury.

The pharmacokinetics of the immunosuppressive agent cyclosporin-A (CsA) were studied in rats submitted to spinal cord (SC) injury. A single CsA 10 mg/kg dose was given either intraperitoneally (i.p.) or orally to rats submitted to experimental SC injury at the T8 level. Twenty four hours after lesion (acute stage of SC injury) i.p. CsA bioavailability was increased, while t1/2 was prolonged. However, oral bioavailability was reduced. Seven weeks after lesion (chronic stage of SC injury) CsA bioavailability, by either route, was not significantly different from control values. Results indicate that parenteral CsA bioavailability is increased during the acute stage of SC lesion, probably due to an impaired elimination. Oral bioavailability, however, is decreased, since there is also an important reduction in gastrointestinal CsA absorption that overrides the effect of impaired elimination. Alterations in CsA pharmacokinetics appear to revert during the chronic stage of SC injury. Changes in CsA bioavailability, depending on the route of administration and on time, must be considered to design an adequate immunosuppressive treatment in SC injury.

Administration, Oral↗
PubMed1996

CA 15-3: a multicentre evaluation of automated and manual tests.

The introduction of a new and automated CA 15-3 immunoassay (IMx Abbott) prompted us to compare the analytical performance of this new test with established tests from CIS ELSA, Sorin, and Boehringer Mannheim in a multicentre study. CA 15-3 measurements in blood samples of breast tumour patients, comparison of intra- and inter-assay variation, dilution linearity, and lower limit of detection are described. The study showed improved precision for the automated over the manual test systems (intra-assay variation: IMx < 5%, CIS ELSA 4-9%, ES 300 < 3% and ETI Sorin > 10%; inter-assay variation: IMx < or = 8%, CIS ELSA < or = 19%, ES 300 < or = 9% and ETI Sorin < or = 27%). Results on patients' samples (n = 101 to 184) showed highly comparable results; IMx vs CIS ELSA site 1: r = 0.950; IMx vs CIS ELSA site 2: r = 0.998; IMx vs ES 300: r = 0.980; IMx vs ETI Sorin: r = 0.931. Slopes of regression lines varied from 0.666 for IMx vs ETI Sorin to 0.988 for IMx vs CIS ELSA (site 1, where heparin plasma was used instead of serum as recommended by the manufacturer found to be only slightly dependent on assay ranges analysed by statistical procedures applied. Despite good correlations between methods, it is recommended that samples collected in the follow-up of disease and at higher CA 15-3 concentrations are analysed by the same test; a changeover to another test is not encouraged.

Automation↗
PubMed1995

Paramyxovirus induced cell fusion. Hemagglutination and hemolysis is enhanced by methylphenidate.

The influence of methylphenidate (MP) upon cell fusion, hemagglutination and hemolysis induced by paramyxovirus was evaluated in vitro. A direct correlation between MP concentrations (range 40 mg/ml to 1.25 mg/ml) and hemagglutination and hemolysis induced by Newcastle disease virus (NDV) was found. Furthermore, MP (500 micrograms/ml) increased formation of the syncytia by LPM paramyxovirus in PK-15 cells. It is fair to speculate that MP leads to activation of the F and/or HN proteins in paramyxovirus by mechanisms other than proteolytic cleavage.

Animals↗
PubMed1995

Ovine lentivirus infection: an animal model for pediatric HIV infection?

While the incidence of the human immunodeficiency virus (HIV) infection has leveled off somewhat in homosexual men, infection in women, children and adolescents is rising. Unless effective preventive measures are introduced, the number of pediatric patients with HIV and related illnesses will continue to increase. Animal models play a key role in the understanding of the pathogenesis and in the establishment of therapeutic approaches of infectious diseases. Ovine lentivirus (OvLV) comprises a subgenus of the lentivirus genus in the family Retroviridae, that shares genotypic, phenotypic and pathogenic features with HIV. Infection of sheep with OvLV results in a progressive chronic disease characterized by cachexia and chronic active inflammation in the lungs, lymph nodes, joints, mammary gland and the central nervous system. Pulmonary lesions in OvLV-affected sheep consist of lymphoid interstitial pneumonia (LIP) and lyphocytic alveolitis. Similarly, these pulmonary lesions also occur in up to 40% of HIV-infected children and in some adults with AIDS. Neonatal lambs experimentally inoculated intratracheally with OvLV develop LIP in 5 to 6 months, thus shortening by several years the natural incubation period and resembling the shorter incubation period observed in children with HIV-associated LIP. However, unlike HIV, OvLV does not infect CD4+T lymphocytes; OvLV only infects and replicates in macrophages. Recent studies indicate that macrophage tropic HIV plays an important role in disease progression. Similarities between HIV and OvLV argue for the use of ovine lentivirus infection as a model to advance in the understanding of some of the aspects of HIV infection.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1993

Entamoeba histolytica: antibody response to recent and past invasive events.

Sero-epidemiological data from endemic amoebiasis areas are difficult to evaluate because the serology of individuals affected by an active process of Entamoeba histolytica tissue invasion is, at present, almost impossible to distinguish from that of individuals who have had an invasive event in the past. The present study compares serum antigenic recognition frequencies among three groups of individuals with different infective conditions: amoebic liver abscess patients; asymptomatic cyst passers; and individuals who have had amoebic liver abscess from one to three years before the study. Control groups consisted of Mexican and Canadian healthy adults. Western blots of E. histolytica membrane extract antigen were reacted with sera from the studied individuals, recognition frequency values were calculated and immunoplots of frequency differences were constructed. The results obtained suggest that the identification and purification of antigenic fractions, which are frequently recognized by sera of amoebic liver abscess patients (136, 132, 93, 70 and 62 kDa), or preferentially associated with past invasive events (144, 140 and 49 kDa), or related to the E. histolytica cyst passer condition (62 and 136 kDa), are important improvements in the use of serology for diagnosis and epidemiological studies in endemic areas of amoebiasis.

Adult↗
PubMed1992

[Interposition connectors with heparin coating for vascular anastomosis of microsurgical tissue flaps].

The intraluminal surface of interposition connectos which are introduced for the quick vascular connection of microsurgical free flaps was coated by heparin. This heparin coating proved to be stable at the polyurethane wall until the intraluminal surface of the interposition connectors with a length of 15 mm was coated by a layer of endothelial cells. 90% of the experimental venous connections didn't show a thrombus formation and were open for the blood flow 10 days postoperatively. The experimental free flaps which were connected by this way had survived 21 days postoperatively and showed a regular healing.

Anastomosis, Surgical↗
PubMed1991

Disseminated cytomegalovirus infection of the female genital tract.

A woman with severe immunosuppression provoked by the acquired immunodeficiency syndrome developed a disseminated cytomegalovirus infection of the genital tract. Using in situ hybridization and the APAAP technique, cytomegalovirus was detected in epithelial and endothelial cells as well as in macrophages in the vulva, the vagina and the cervix uteri.

Acquired Immunodeficiency Syndrome↗
PubMed1991

[Non-tropical sprue and chronic inflammatory rectal stenosis in a patient with abuse of ergotamine-containing suppositories].

A 51 year old Yugoslavian patient was admitted to our hospital in reduced general condition with distinct hypocalcemia, osteomalacia, and with rectum stenosis. Our investigations led to the diagnosis of a malabsorption syndrome due to non-tropical sprue. The most likely cause of the rectum stenosis is an abuse of ergotamine-containing suppositories for several years. A gluten-free diet and the interruption of the use of the suppositories improved her general condition remarkably.

Bone Density↗
PubMed1990

[CMV virus infection of the vulva and vagina].

Clinical and histopathological findings of a woman with AIDS and an ulcerated vulvovaginitis are presented. The preliminary diagnosis of a herpes vulvitis was corrected after in-situ-hybridisation of the formalin-fixed and paraffin-embedded tissue. CMV was found in macrophages and endothelial cells in the vulva and vagina. In view of the increase in the number of immuno-suppressed patients these findings should direct clinical attention to this so far unusual manifestation of a CMV-infection.

Adult↗
PubMed1990

[The eosinophil and Entamoeba histolytica. II. Testicular amebic lesions produced in eosinophilic rats].

Even though eosinophiles are not characteristic of amebiasis, polymorphonuclear eosinophilic cells are regularly found in the inflammatory lesion which occurs in the early phases of amebic invasion. To acquire better knowledge of the intervention of these cells when confronted with E. histolytica, testicular lesions were produced by means of direct injection of amebas in rats with eosinophilia. Eosinophilia (greater than or equal to 4%) was induced in male Sprague Dawley rats by an intravenous injection of Sephadex G200 suspension. Later, both the eosinophilic and normal (control) rats were challenged with an intratesticular injection (on the left side) of 2 x 10(6) amebas of the virulent strain HM1-IMSS. The other testicle was injected with BFS-A to serve as control. The testicles were removed 5 hours later and evaluated histologically. The size and celullarity of the testicular lesions produced by the ameba on both eosinophilic and controls were similar, whereas lesions were not found in testicles injected with BSF-A. Within the limits of our experimental model, the results suggest that eosinophils do not contribute substantially to the genesis of tissue lesions produced by E. histolytica.

Animals↗
PubMed1990

[Histocompatibility antigens and acute vascular purpura].

INTRODUCTION: Some kidney diseases are associated to HLA antigens. Nyulassy found an increase in HLA-B35 in patients with Henoch-Schönlein's purpura suffering nephritis (HSP-N). Our study searched for associations of HLA antigens and anaphylactoid purpura nephritis in Mexican mestizo patients. MATERIAL AND METHODS: HLA-A,B, and C antigens were detected by two-step microcytotoxicity in 22 patients with HSP-N and compared to those of 665 healthy subjects of the same ethnic background. RESULTS: A significant association was found between HSP-N and HLA-Aw19 single (pc less than 0.05) or in haplotype form (Aw19-B35) (pc less than 0.005). HLA B35 alone was associated to HSP-N but only at non corrected level (pc less than 0.05). DISCUSSION: The significant association between HLA-Aw19 and Aw19-B35 and HSP-N may indicate a risk factor in Mexican mestizo patients to develop this case.

Adolescent↗
PubMed1989

In vivo 31P NMR spectroscopy of energy rich phosphates in the brain of the hyperammonemic rat.

Hyperammonemia is a major contributing factor to the neurological abnormalities observed in hepatic encephalopathy and in congenital defects of ammonia detoxication. In rats variable changes in labile energy rich phosphates in the brain have been observed in hyperammonemia using biochemical methods. Using 31P-NMR spectroscopy however no significant changes of the relative concentrations of the energy rich phosphates alpha, beta and gamma-ATP, phosphocreatine, inorganic phosphate and the pH were found in the fronto parietal cortex of the urease treated hyperammonemic rat. Alterations in the metabolites of these compounds do not appear to be a major pathomechanism of ammonia toxicity in this brain area.

Ammonia↗
PubMed1985

Inhibition of human monocyte locomotion by products of axenically grown E. histolytica.

The supernatant fluid of axenically grown E. histolytica inhibits chemotaxis, chemokinesis and random mobility of human mononuclear phagocytes (MP) as measured in Boyden chambers. Human polymorphonuclear phagocytes (PMN) locomotion is apparently unaffected. The factor was found in comparable amounts in the supernatant fluid of axenic cultures of four E. histolytica strains that differed in their human pathogenicity and virulence, as well as in two entamoebas non-pathogenic for man. This dialysable and thermolabile MP-locomotion inhibiting entamoeba product (EP) can be absorbed out by incubation with MP, but not with lymphocytes, while partial absorption was observed using PMN. The MP-locomotion inhibitory effect of this EP was cancelled by inhibiting protein synthesis in the MP by means of cycloheximide. In vivo, this EP caused a delay in MP migration in Rebuck skin windows. The molecular weight of this EP lies between 478 and 765 by gel-sieve chromatography. Our results suggest a direct effect upon the cytoskeletal and locomotive apparatus of the MP. This MP-locomotion inhibiting EP could contribute to the paucity of the inflammatory reaction observed in the advanced stages of invasive amoebiasis and consequently also to the lack of scar tissue formation upon healing of amoebic lesions.

Adult↗