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Biomedical subjects

W Zimmerli

Publications and source records attributed to W Zimmerli.

At least 55 records · Page 3Linked to original sources
PubMed1999

Duke criteria-negative endocarditis caused by Bartonella quintana.

Bartonella spp. were recently recognized as causative agents of culture-negative endocarditis. Molecular techniques, such as broad-range PCR, are now available to detect fastidious or slow-growing microorganisms, or those which cannot be cultured. Such microorganisms may be responsible for culture-negative endocarditis. Alcoholism and homelessness are known risk factors for Bartonella quintana endocarditis, even in patients without previous valvular disease. We report a case of B. quintana endocarditis diagnosed by PCR amplification on the excised heart valve, in a young non-alcoholic and immunocompetent patient with few clinical signs of infection who did not fulfill the Duke criteria.

Adult↗
PubMed1999

Meropenem (1.5 g/day) is as effective as imipenem/cilastatin (2 g/day) for the treatment of moderately severe intra-abdominal infections.

This multicentre, open-label, randomised trial compared meropenem (0.5 g/8 h) and imipenem/cilastatin (at the commonly used dosage of 0.5 g/6 h) in monotherapy in patients with moderately severe intra-abdominal infections (IAIs). In total, 161 patients were randomised (82 meropenem, 79 imipenem/cilastatin). The mean APACHE II scores in the two groups were 5.8 and 6.4, respectively. At the end of therapy, 65/71 (91.6%) evaluable meropenem recipients were clinically cured or improved, compared to 60/64 (93.8%) imipenem/cilastatin recipients. This difference and that in an intention-to-treat analysis (82.1 vs 86.1%, respectively), were not statistically significant. Both drugs were generally well tolerated. Thus, meropenem 0.5 g/8 h is as clinically effective and well tolerated as imipenem/cilastatin 0.5 g/6 h in moderately severe IAIs.

APACHE↗
PubMed1999

Pneumocystis carinii pneumonia in human immunodeficiency virus (HIV)-positive and HIV-negative immunocompromised patients.

For 89 human immunodeficiency virus (HIV)-positive and 32 HIV-negative immunocompromised patients who had 121 episodes of Pneumocystis carinii pneumonia (PCP), clinical features and changes over time were compared. HIV-infected patients characteristically had a longer duration of symptoms (23 vs. 13 days; P<.005); were younger (39 vs. 48 years; P<.001); had a higher frequency of sweating, weight loss, and thoracic pain; and had fewer admissions to the intensive care unit (16% vs. 31%; P<.05). In addition, they had significantly higher hemoglobin levels, lower thrombocyte counts, lower C-reactive protein values, and a higher proportion of eosinophils and lymphocytes in bronchoalveolar lavage fluid. After 1995, HIV-negative patients' mean length of stay dropped from 34 days to 16 days (P<.005), and their hospital mortality rate dropped from 29% to 7% (P<.001). HIV-positive patients with PCP differed in several aspects from those without HIV infection. Knowledge gained from experience with treatment of opportunistic infections in patients with AIDS has improved the management of PCP in patients with other immunodeficiencies.

Acquired Immunodeficiency Syndrome↗
PubMed1999

Predictive value of cerebrospinal fluid (CSF) lactate level versus CSF/blood glucose ratio for the diagnosis of bacterial meningitis following neurosurgery.

The value of cerebrospinal fluid (CSF) lactate level and CSF/blood glucose ratio for the identification of bacterial meningitis following neurosurgery was assessed in a retrospective study. During a 3-year period, 73 patients fulfilled the inclusion criteria and could be grouped by preset criteria in one of three categories: proven bacterial meningitis (n = 12), presumed bacterial meningitis (n = 14), and nonbacterial meningeal syndrome (n = 47). Of 73 patients analyzed, 45% were treated with antibiotics and 33% with steroids at the time of first lumbar puncture. CSF lactate values (cutoff, 4 mmol/L), in comparison with CSF/blood glucose ratios (cutoff, 0.4), were associated with higher sensitivity (0.88 vs. 0.77), specificity (0.98 vs. 0.87), and positive (0.96 vs. 0.77) and negative (0.94 vs. 0.87) predictive values. In conclusion, determination of the CSF lactate value is a quick, sensitive, and specific test to identify patients with bacterial meningitis after neurosurgery.

Adult↗
PubMed1998

Role of rifampin for treatment of orthopedic implant-related staphylococcal infections: a randomized controlled trial. Foreign-Body Infection (FBI) Study Group.

CONTEXT: Rifampin-containing regimens are able to cure staphylococcal implant-related infections based on in vitro and in vivo observations. However, this evidence has not been proven by a controlled clinical trial. OBJECTIVE: To evaluate the clinical efficacy of a rifampin combination in staphylococcal infections associated with stable orthopedic devices. DESIGN: A randomized, placebo-controlled, double-blind trial conducted from 1992 through 1997. SETTING: Two infectious disease services in tertiary care centers in collaboration with 5 orthopedic surgeons in Switzerland. PATIENTS: A total of 33 patients with culture-proven staphylococcal infection associated with stable orthopedic implants and with a short duration of symptoms of infection (exclusion limit <1 year; actual experience 0-21 days). INTERVENTION: Initial debridement and 2-week intravenous course of flucloxacillin or vancomycin with rifampin or placebo, followed by either ciprofloxacin-rifampin or ciprofloxacin-placebo long-term therapy. MAIN OUTCOME MEASURES: Cure was defined as (1) lack of clinical signs and symptoms of infection, (2) C-reactive protein level less than 5 mg/L, and (3) absence of radiological signs of loosening or infection at the final follow-up visit at 24 months. Failure was defined as (1) persisting clinical and/or laboratory signs of infection or (2) persisting or new isolation of the initial microorganism. RESULTS: A total of 18 patients were allocated to ciprofloxacin-rifampin and 15 patients to the ciprofloxacin-placebo combination. Twenty-four patients fully completed the trial with a follow-up of 35 and 33 months. The cure rate was 12 (100%) of 12 in the ciprofloxacin-rifampin group compared with 7 (58%) of 12 in the ciprofloxacin-placebo group (P=.02). Nine of 33 patients dropped out due to adverse events (n=6), noncompliance (n=1), or protocol violation (n=2). Seven of the 9 patients who dropped out were subsequently treated with rifampin combinations, and 5 of them were cured without removal of the device. CONCLUSION: Among patients with stable implants, short duration of infection, and initial debridement, patients able to tolerate long-term (3-6 months) therapy with rifampin-ciprofloxacin experienced cure of the infection without removal of the implant.

Aged↗
PubMed1998

Efficacy, safety, and tolerance of piperacillin/tazobactam compared to co-amoxiclav plus an aminoglycoside in the treatment of severe pneumonia.

An open, randomized, multicenter study was conducted to compare the efficacy and safety of piperacillin/tazobactam and co-amoxiclav plus aminoglycoside in the treatment of hospitalized patients with severe community-acquired or nosocomial pneumonia. Of the 89 patients who entered the study, 84 (94%) were clinically evaluable. A favorable clinical response was observed in 90% of the piperacillin/ tazobactam group and in 84% of the co-amoxiclav/aminoglycoside group (not significant). The bacteriological efficacy was comparable in both groups (96% vs. 92%; not significant). There was only one fatal outcome in the piperacillin/tazobactam group compared to six in the co-amoxiclav/aminoglycoside group regimen (P=0.058). The adverse event rate was non-significantly lower in the piperacillin/ tazobactam group compared to the co-amoxiclav/aminoglycoside group (2% vs. 7%; P=0.32). Piperacillin/tazobactam is safe and highly efficacious in the treatment of serious pneumonia in hospitalized patients. It compares favorably with the combination of co-amoxiclav/aminoglycoside.

Aged↗
PubMed1998

Rifampin concentrations in various compartments of the human brain: a novel method for determining drug levels in the cerebral extracellular space.

Antimicrobial therapy for brain infections is notoriously difficult because of the limited extent of knowledge about drug penetration into the brain. Therefore, we determined the penetration of rifampin into various compartments of the human brain, including the cerebral extracellular space (CES). Patients undergoing craniotomy for resection of primary brain tumors were given a standard dose of 600 mg of rifampin intravenously before the operation. A microdialysis probe (10 by 0.5 mm) was inserted into the cortex distantly from the resection and was perfused with two different rifampin solutions. Rifampin concentrations in the CES were calculated by the no-net-flux method. Intraoperatively, samples were taken from brain tumor tissue, perifocal tissue, and normal brain tissue in the case of pole resections. Rifampin concentrations in the various samples were determined by using a bioassay with Sarcinea lutea. In the various compartments, rifampin concentrations were highest within tumors (1.37 +/- 1.34 microg/ml; n = 8), followed by the perifocal region (0.62 +/- 0.67 microg/ml; n = 8), the CES (0.32 +/- 0.11 microg/ml; n = 6), and normal brain tissue (0.29 +/- 0.15 microg/ml; n = 7). Rifampin concentrations in brain tumors do not adequately reflect concentrations in normal brain tissue or in the CES. Rifampin concentrations in the CES, as determined by microdialysis, are the most reproducible, and the least scattered, of the values for all compartments evaluated. Rifampin concentrations in all compartments exceed the MIC for staphylococci and streptococci. However, CES concentrations may be below the MICs for some mycobacterial strains.

Adult↗
PubMed1998

Impact of bacterial biofilm formation on in vitro and in vivo activities of antibiotics.

The impact of bacterial adherence on antibiotic activity was analyzed with two isogenic strains of Staphylococcus epidermidis that differ in the features of their in vitro biofilm formation. The eradication of bacteria adhering to glass beads by amikacin, levofloxacin, rifampin, or teicoplanin was studied in an animal model and in a pharmacokinetically matched in vitro model. The features of S. epidermidis RP62A that allowed it to grow on surfaces in multiple layers promoted phenotypic resistance to antibiotic treatment, whereas strain M7 failed to accumulate, despite initial adherence on surfaces and growth in suspension similar to those for RP62A. Biofilms of S. epidermidis M7 were better eradicated than those of strain RP62A in vitro (46 versus 31%; P < 0.05) as well as in the animal model (39 versus 9%; P < 0.01).

Animals↗
PubMed1998

Soluble CD14 activates monocytic cells independently of lipopolysaccharide.

The glycoprotein CD14 acts as a receptor for lipopolysaccharide (LPS), either when anchored in the myeloid cell membrane (mCD14) or as a soluble molecule (sCD14) in serum. sCD14-LPS complexes activate cells devoid of mCD14. However, the role of sCD14 independent of LPS is unknown. Therefore, the effect of sCD14 on monocyte functions was investigated in the monocytic cell lines THP1 and Mono Mac 6 and in fresh human monocytes. Under serum-free conditions, endotoxin-free human recombinant sCD14(1-348), (rsCD14(1-348)) induced tumor necrosis factor alpha (TNF-alpha). The TNF-alpha effect was stronger in THP1 cells than in Mono Mac 6 cells or monocytes. It was dose dependent, with a maximum at 1 microg/ml, and time dependent, with a maximum after 2 h. sCD14 purified from urine had the same cytokine-activating capacity. In contrast, C-terminally truncated rsCD14(1-152) was inactive. The rsCD14 effect was not due to LPS contamination, since it was resistant to polymyxin and lipid IVa but sensitive to heat and trypsin. The rsCD14-induced cytokine induction was blocked by preincubation of rsCD14 with a monoclonal anti-CD14 antibody that did not recognize the LPS-binding site. Release of the TNF-alpha disappeared upon pretreatment of rsCD14 in 50% plasma or in complete, heat-inactivated or sCD14-depleted serum. Moreover, cytokine production was no longer observed when rsCD14 was pretreated with thrombocytes. The thrombocyte effect was dose and time dependent. In conclusion, sCD14 is able to activate myeloid cells, and the effect is prevented by the presence of plasma, serum, or thrombocytes.

Cell Line↗
PubMed1997

[HIV-associated lung diseases].

Over two-thirds of all HIV-infected individuals have an associated pulmonary disease. The following causes are frequently observed: bacterial infection (Streptococcus pneumoniae, Haemophilus influenzae and mycobacteria), protozoal infection (Pneumocystis carinii), fungal infection (Cryptococcus neoformans and Histoplasma capsulatum), viral infection (cytomegalovirus), tumors (Kaposi's sarcoma) and pneumonitis. For diagnosis and patients' immune status, imaging techniques, and microbiological, cytological and histological examination of respiratory secretions and biopsy material are important. Infection with Pneumocystis carinii remains common as a cause of respiratory disease in HIV-infected patients, mainly those without prophylaxis. The clinical presentation of pulmonary tuberculosis varies with the state of immunity. Kaposi's sarcoma is the commonest HIV-associated malignancy, and may affect the lungs in addition to the skin.

AIDS-Related Opportunistic Infections↗
PubMed1997

[Chest pain and fever].

A 26 year old women was seen at our outpatient clinic because of fever, dyspnea, chest pain and night sweats. An echocardiography revealed a moderate pericardial effusion. Therapy with a nonsteroidal anti-inflammatory drug was started, but the patient did not improve clinically. A new left pleural effusion became manifest. Usual laboratory tests, serological tests and examination of pleural effusion were not conclusive. However, a tuberculin skin test was positive. The etiologic diagnosis of this pericarditis and pleuritis was obtained by thoracoscopic pleural biopsy, which yielded Mycobacterium tuberculosis.

Adult↗
PubMed1997

Low risk of bacteremia during catheter replacement in patients with long-term urinary catheters.

BACKGROUND: Geriatric patients with long-term urinary catheters have an increased morbidity and mortality. It is conceivable that catheter replacement causes bacteremia and contributes to this morbidity and mortality. The purpose of our study was to determine the incidence and clinical relevance of bacteremia induced by urinary catheter replacements. METHODS: We analyzed clinical signs and symptoms and laboratory measures (leukocyte count, C-reactive protein, urine sediment, urine culture) during 120 routine catheter replacements in geriatric patients. In addition, blood cultures were drawn before and at 5, 15, and 30 minutes after catheter replacement. RESULTS: The urine cultures showed growth of 1 to 5 different microorganisms before replacement. Of 480 blood cultures, 27 (5.6%) were positive. However, the same species grew from blood and urine in only 5 catheter replacements. None of the patients met criteria for systemic inflammatory response syndrome. There were no significant differences in clinical and laboratory findings between patients with and without bacteremia. Coagulase-negative staphylococci grew in 12 blood cultures. Their distribution over time suggested that they mainly represented catheter replacement-related bacteremia rather than contaminants. Consequently, 64 intraurethral catheter segments were additionally cultured. Coagulase-negative staphylococci grew in 10 catheter cultures, but in only 2 simultaneously cultured urine samples. CONCLUSION: Bacteremia induced by routine replacement of long-term urinary catheters occurred in 4.2% (5/120) of replacements in geriatric patients. Such bacteremia did not have a detectable clinical relevance in our study.

Aged↗
PubMed1997

Eosinophilia in patients infected with the human immunodeficiency virus.

The prevalence and significance of peripheral blood eosinophilia in patients infected with the human immunodeficiency virus (HIV) were evaluated. Fifteen of 119 consecutive patients had absolute eosinophil counts of > 450/mm3. During a mean follow-up period of 419 days eosinophilia could be identified as secondary to a parasitic infection in only one patient. Correlation with disease stage showed a higher rate of advanced disease in patients with absolute eosinophilia. In a multivariate regression analysis, only low CD4+ cell counts, not the CDC disease stage or the use of antiretroviral therapy or primary prophylaxis, contributed significantly to the prevalence of eosinophilia. It is concluded that expensive laboratory investigations in asymptomatic patients with advanced-stage HIV disease are neither necessary nor cost effective.

Adult↗
PubMed1997

Vertebral osteomyelitis caused by group B streptococci (Streptococcus agalactiae) secondary to urinary tract infection.

Infections due to group B streptococci usually occur in the peri- and neonatal setting or in adults with chronic underlying diseases. A case of pyogenic vertebral osteomyelitis caused by Streptococcus agalactiae in a 54-year-old man suffering from phimosis with urinary retention and urinary tract infection is reported. This case adds to the few existing reports of vertebral osteomyelitis caused by group B streptococci.

Humans↗