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Biomedical subjects

S Peters

Publications and source records attributed to S Peters.

At least 109 records · Page 6Linked to original sources
PubMed1998

Growth inhibitory and bactericidal efficacy of sera from Lyme borreliosis patients on B. burgdorferi strains.

Two B. afzelii strains EB1 and FEM1, classified in normal human sera (NHS) as serum-resistant, and an intermediate serum-sensitive B. burgdorferi s.s. strain 297, were tested in regard of their serum sensitivity in immune sera (IS) of patients at all stages of Lyme borreliosis by a growth inhibition assay (GIA). Fifty-four per cent (13/24) of the tested IS were GIA positive, while the sera of patients in stage III disease inhibited the growth more frequently than did the patients with sera of stage II or stage I disease. Growth inhibition was predominantly directed against strain FEM1 (12/24), less against strain EB1 (4/24) and strain 297 (2/24). A growth inhibiting effect on two strains was only detectable for two IS and merely one stage III serum inhibited all three strains. Positive results in the GIA required fresh serum and resulted in the killing of the borreliae. The detection of the deposited complement components C3 and C9 on the surfaces of the inhibited strains by means of immunofluorescence assays confirmed the role of complement. In Westernblot analyses of strain FEM1, it was striking that GIA-positive IS reacted 3- to 5-fold more often with proteins of molecular masses of 48.9-, 38.6-, 27.5-, 25-, 23.1- (OspC), 21.7-, and 16-kDa, than did GIA-negative IS. Furthermore, two proteins of approximately 20- and 31.2-kDa reacted exclusively with GIA-positive IS. Antibodies reacting with these proteins could play a role in the growth inhibition of NHS-resistant borrelial strains, OspC.

Antigens, Bacterial↗
PubMed1998

Serologic evidence for tick-borne pathogens other than Borrelia burgdorferi (TOBB) in Lyme borreliosis patients from midwestern Germany.

The seroprevalence of antibodies against the human granulocytic ehrlichiosis agent (HGE) and Babesia microti was retrospectively determined in 76 Lyme borreliosis patients and in 44 asymptomatic individuals with a positive borreliosis serology, in comparison to 100 healthy blood donors from the Rhein-Main area. Additionally, seroreactivity for tick-borne encephalitis virus (TBEV) was investigated. For antibody detection, commercially available immunofluorescence assays (MRL Diagnostics, USA) and a TBEV-ELISA (Immuno, Germany) were used. In the control group, the positivity rate for anti-Borrelia burgdorferi (IgG/IgM) and anti-Babesia microti-antibodies in the population of the Rhein-Main area (Midwestern Germany) may be estimated at 15% and 8%, respectively. Examination for both HGE and TBEV demonstrated seroreactivity (IgG) in 1% of tested individuals. Specific anti-HGE IgG and/or IgM antibodies were more often discovered in cases of early Borrelia infection (stage I: 13.6%, stage II: 18.4%) than in patients with stage III disease (0%) or in seropositive but asymptomatic patients (6.8%). Investigation for TBEV revealed seroreactivity for IgG in 13% of these cases. No TBEV-IgM was found. Interestingly, the prevalence of anti-HGE and anti-TBEV antibodies among Lyme borreliosis patients and seropositive patients without active Lyme disease symptoms was significantly higher than that in the control group of healthy blood donors (p < 0.05). Likewise, antibody titers reflecting a recent infection with Babesia microti could be demonstrated more often in patients with Lyme borreliosis stage I or II (p < 0.05). Analysis of 50 samples from patients with florid or recent syphilis infection revealed no crossreactivity between Babesia microti, HGE and Treponema pallidum. Our findings suggest that concomitant or serial infection due to TOBB may be common in tick exposed patients from the Rhein-Main area and in European countries in general. Hence, in addition to TBEV, human babesiosis and HGE should always be considered by European physicians in the differential diagnosis of acute febrile illness following a tick bite.

Animals↗
PubMed1998

A comparison of sucralfate and ranitidine for the prevention of upper gastrointestinal bleeding in patients requiring mechanical ventilation. Canadian Critical Care Trials Group.

BACKGROUND: Critically ill patients who require mechanical ventilation are at increased risk for gastrointestinal bleeding from stress ulcers. There are conflicting data on the effect of histamine H2-receptor antagonists and the cytoprotective agent sucralfate on rates of gastrointestinal bleeding, ventilator-associated pneumonia, and mortality. METHODS: In a multicenter, randomized, blinded, placebo-controlled trial, we compared sucralfate with the H2-receptor antagonist ranitidine for the prevention of upper gastrointestinal bleeding in 1200 patients who required mechanical ventilation. Patients received either nasogastric sucralfate suspension (1 g every six hours) and an intravenous placebo or intravenous ranitidine (50 mg every eight hours) and a nasogastric placebo. RESULTS: The patients in the two groups had similar base-line characteristics. Clinically important gastrointestinal bleeding developed in 10 of 596 (1.7 percent) of the patients receiving ranitidine, as compared with 23 of 604 (3.8 percent) of those receiving sucralfate (relative risk, 0.44; 95 percent confidence interval, 0.21 to 0.92; P=0.02). In the ranitidine group, 114 of 596 patients (19.1 percent) had ventilator-associated pneumonia, as compared with 98 of 604 (16.2 percent) in the sucralfate group (relative risk, 1.18; 95 percent confidence interval, 0.92 to 1.51; P=0.19). There was no significant difference between the groups in mortality in the intensive care unit (ICU) (23.5 percent in the ranitidine group and 22.9 percent in the sucralfate group) or the duration of the stay in the ICU (median, nine days in both groups). CONCLUSIONS: Among critically ill patients requiring mechanical ventilation, those receiving ranitidine had a significantly lower rate of clinically important gastrointestinal bleeding than those treated with sucralfate. There were no significant differences in the rates of ventilator-associated pneumonia, the duration of the stay in the ICU, or mortality.

Aged↗
PubMed1998

Unacceptable results of the Mayo procedure for repair of abdominal incisional hernias.

OBJECTIVE: To evaluate the current practice of incisional hernia repair in Germany and analysis of the results of the Mayo duplication technique done in our hospital over a 10-year period. DESIGN: Nationwide survey, retrospective analysis. SETTING: University department, Germany. SUBJECTS: Survey of most surgical departments and of 114 patients with 135 incisional hernias in our unit. INTERVENTION: Mayo duplication repair incisional hernias. MAIN OUTCOME MEASURES: Common practice, recurrence rates, quality of life. RESULTS: The Mayo overlap is the preferred technique in most surgical departments. The estimated failure rates (12% or less) in general practice are grossly underestimated. In our hospital the recurrence rate after Mayo duplication repair was 61/114 (54%) during a follow up time of 5.7 years with a follow-up-rate of 84%. Univariate and multivariate analyses failed to identify any predisposing factors. All patients with incisional hernias had limitations their physical function. CONCLUSIONS: The widely used Mayo procedure leads to unacceptable results for repair of incisional hernias and other techniques should be evaluated and used more often. Repair of an incisional hernia does not improve overall quality of life.

Female↗
PubMed1998

Repetitive bone marrow transplantation in nonmyeloablated recipients.

Transplantation of 200 million male BALB/c marrow cells into normal nonmyeloablated female BALB/c hosts results in relatively high levels of engraftment, whether the cells are infused repetitively over time or in a single infusion. These high engraftment rates suggested that repetitive injections of high levels of male BALB/c cells might be able to totally replace host marrow. Accordingly, we transplanted 40x10(6) male BALB/c bone marrow cells into female BALB/c recipients over a 7-week period for a total of 20 injections (800x10[6] marrow cells). Engraftment in this experimental group was compared to that seen when female recipients received 2x10(6) male marrow cells or phosphate-buffered saline (PBS) over the same injection schedule. Engraftment was quantitated at 5 and 7 weeks after the final infusion by detection of male-specific sequences in female host marrow, spleen, and thymus by Southern blot analysis using a Y-specific cDNA probe. Male DNA levels were quantitated with a Molecular Dynamics phosphorimager. Engraftment of male cells into female marrow at 5 and 7 weeks posttransplantation ranged from 19 to 88%, whereas that in spleen and thymus ranged between 30 and 100% and 28 and 50%, respectively. The mean percent engraftments for marrow, spleen, and thymus were 41, 69, and 39%, respectively. Mean percent engraftments for 2x10(6) cell infusions at 5 and 7 weeks for marrow, spleen, and thymus were 4, 6, and 4%, respectively. Marrow and spleen cellularity and total high proliferative potential colony-forming cell numbers were determined in PBS- and cell-injected mice. No significant differences between these groups were observed. For marrow engraftment, 20 injections of 40x10(6) cells was not more effective than five, but donor DNA in thymus and spleen was increased with 20 injections. Primitive progenitor cell levels and marrow cellularity do not increase in mice injected with large numbers of marrow cells, suggesting that host marrow cells are replaced rather than augmented by infused donor cells.

Animals↗