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Biomedical subjects

G Höffken

Publications and source records attributed to G Höffken.

At least 19 recordsLinked to original sources

Systemic and endotracheal antibiotic prophylaxis of nosocomial pneumonia in ICU.

Nosocomial pneumonias, especially in ventilated patients, are a continuing problem in modern medicine. Pathogens most commonly involved with these pneumonias are Enterobacteriaceae, Ps. aeruginosa and S. aureus. Several prevention measures for nosocomial pneumonia are possible such as parenteral and topical antibiotics--a very controversial issue. Several studies with parenteral antibiotics, starting as early as 1954, could not prove any benefit of parenteral antibiotics in pneumonia prevention. Topical antibiotics, starting with polymyxin or gentamicin via the endotracheal tube in the 70s, gave controversial results. In a prospective, randomized, double-blind placebo controlled study with gentamicin via the endotracheal tube in ventilated ICU patients we found no significant reduction of pneumonia rate and mortality. However, the combined approach (SDD) of oropharyngeal, gastrointestinal and parenteral use of certain antibiotics appears to give promising results in specific patient subgroups such as ventilated polytrauma patients in ICU.

Administration, Topical

Application of the polymerase chain reaction in the diagnosis of pulmonary toxoplasmosis in immunocompromised patients.

Bronchoalveolar lavage (BAL) fluid from 47 immunocompromised patients (26 with AIDS and 21 patients on immunosuppressive therapy) was analysed for the presence of Toxoplasma gondii DNA by means of the polymerase chain reaction (PCR). Specific target DNA derived from the B1 and P30 gene of Toxoplasma gondii was detected in BAL fluids from three patients with AIDS (6.4%). Pneumonia as the presenting feature of disseminated toxoplasmosis was confirmed by both clinical findings and by detection of Toxoplasma gondii DNA in blood obtained from two patients. The findings indicate that PCR has potential value in the detection of Toxoplasma gondii as an etiologic agent of atypical pneumonia in immunocompromised patients.

Animals

Pharmacokinetics of roxithromycin and influence of H2-blockers and antacids on gastrointestinal absorption.

The pharmacokinetics of roxithromycin (300 mg orally) and the influence of the antacid aluminum magnesium hydroxide and the H2-blocker ranitidine on bioavailability of roxithromycin in ten healthy volunteers were studied. Pharmacokinetics after a single dose of roxithromycin were characterized by high peak serum levels (9.1 +/- 2.1 mg/l) and a long elimination half-life (7.2 +/- 2.5 h), resulting in a large area under the curve (116.9 +/- 32.7 mg h/l). High inter- and intraindividual variations were found for both the absorption time and the elimination half-life. The bioavailability of roxithromycin was not affected by coadministration with antacids or ranitidine.

Adult

[Clinical aspects of endocarditis].

Considering the incidence of infectious endocarditis this disease is still an important clinical entity in internal medicine departments. Leading symptoms are fever, cardiac murmurs, embolic phenomena, skin alterations and also sometimes CNS-disturbances. Two different clinical endocarditis entities can be separated: an acute aggressive course of endocarditis and the subacute course (endocarditis lenta). Diagnostic procedures are mainly based on positive blood cultures and echocardiographic detection of cardiac vegetations. In case of a progressive development of cardiac insufficiency, non treatable infection, large vegetations on valve and embolic phenomena a prosthetic valve implantation is indicated.

Endocarditis, Bacterial

Quinolone pharmacokinetics and metabolism.

The pharmacokinetic properties of the new fluoroquinolones are characterized by a high volume of distribution, long biological half-life, low serum protein binding, elimination by renal and extrarenal mechanisms with high total and renal clearances, limited biotransformation and moderate to excellent bioavailability after oral administration. However, each quinolone derivative (ciprofloxacin, enoxacin, fleroxacin, norfloxacin, ofloxacin and pefloxacin) possesses individual pharmacokinetic parameters, which should be considered in the treatment of patients, especially when liver or renal dysfunction exists.

Administration, Oral

Comparative pharmacokinetics of glycopeptide antibiotics, and the influence of teicoplanin on granulocyte function.

The glycopeptide antibiotics teicoplanin and vancomycin differ in their pharmacokinetic properties. Teicoplanin is characterized by a high and prolonged serum concentration as a result of its long elimination half-life, which can be explained by high serum protein binding and renal tubular resorption. The apparent volume of distribution of teicoplanin is much larger than the extracellular space of the human body, indicating intracellular accumulation in different tissues. Elimination is primarily via the kidneys, though 15-20% is eliminated by non-renal mechanisms. Vancomycin has a shorter elimination half-life and lower protein binding than teicoplanin. At therapeutically relevant serum concentrations, teicoplanin has no influence on superoxide anion production and enzyme release by granulocytes.

Cells, Cultured

[Randomized comparative study of secondary prevention of Pneumocystis carinii pneumonia in patients with acquired immunologic deficiency syndrome].

Pneumocystis carinii pneumonia is one of the most frequent infectious complications in patients with the acquired immunodeficiency syndrome (AIDS). A prospective trial was initiated to compare azidothymidine alone with azidothymidine plus aerosolized pentamidine as a secondary prophylaxis for pneumocystis carinii pneumonia. 27 patients (24 male, three female, average age 39 years) were enrolled, 14 patients receiving azidothymidine and pentamidine aerosol and 13 azidothymidine alone. After 166 days of follow-up, this trial had to be terminated prematurely, since the efficacy of pentamidine aerosol in the prevention of pneumocystis carinii pneumonia was clearly demonstrated in two recently published studies. Two patients died during the study period, one in either group, but neither due to pneumocystis carinii pneumonia. Two patients developed histologically proven pneumocystis carinii pneumonia; both patients were allocated to the azidothymidine arm. Pneumocystis carinii pneumonia was suspected clinically but not proven in four patients, three were randomized in the azidothymidine arm. Pentamidine was well tolerated and produced no severe side effects. The sample size is too small to draw definitive conclusions concerning the efficacy of pentamidine aerosol in AIDS patients.

Acquired Immunodeficiency Syndrome

[Intensive care problems in AIDS patients].

The discussion regarding the need for intensive-care treatment of AIDS patients should be conducted in a highly differentiated manner and should depend on the prognosis of the underlying or basic disease, on the immunological situation, on the mental condition and on the consent of the individual patient. During the past two years the treatment results have improved markedly by the use of steroids, especially in pneumocystis carinii pneumonia.

Acquired Immunodeficiency Syndrome

[Value of diagnostic procedures in fiberoptic bronchoscopy of pulmonary infections].

Fibreoptic bronchoscopy has become an important means of diagnosing infections of the lower respiratory tract, since it a method with few complications, whereas, on the other hand, the conventional non-invasive methods are hardly reliable in respect of diagnostic relevance. Frequent oropharyngeal contamination severely limits the significant assessment of the pathogenicity of cultured microorganisms. The protected specimen brush (PSB) or quantitative cultures of bronchoalveolar lavage (BAL) might be useful in solving this problem. These methods were studied in two prospective trials comprising 123 patients with suspected bronchopulmonary infection and 54 control patients. Both methods were found to be disappointing in respect of sensitivity; moreover, quantitative cultivation did not yield any differences with regard to specificity.

Bacterial Infections

[Community-acquired pneumonia].

In a prospective study 212 patients were analysed who, between 1. 10. 1982-31.12. 1983 and 1. 10. 1985-31. 12. 1986, had been admitted to hospital because of pneumonia. The causative organism was identified in 127 of the 212 patients (60%). Pneumococcus was the most common organism (n = 64), as demonstrated by culture and immunological techniques of determining antigen or antibody. Next most common was Legionella (n = 15) of various species. Mixed infections were found in 11 patients, in all instances associated with pneumococci. There were 24 deaths (11.3%). It is concluded from these results that (1) determination of pneumococcal antigen in sputum, but not in urine or serum, can improve the identification of the causative organism; (2) Legionella is one of the most common causes of pneumonia acquired outside of hospital; and (3) adequate serological diagnosis of Legionnaire's disease is possible only if a large number of different species are tested for.

Adolescent

Small intestinal structure and function in patients infected with human immunodeficiency virus (HIV): evidence for HIV-induced enteropathy.

STUDY OBJECTIVE: To determine small intestinal mucosal structure and function in patients with human immunodeficiency virus (HIV) infection. DESIGN: Prospective, consecutive sample study. SETTING: Referral-based medical clinics at a municipal and a university medical center. PATIENTS: Forty-five HIV-infected patients (44 men, 1 woman) with gastrointestinal complaints. INTERVENTIONS: All patients had esophagogastroduodenoscopy. Distal duodenal biopsy samples were examined morphometrically and by quantitative enzyme histochemical techniques. Immunohistologic studies were done to determine whether HIV antigen p24 was present. Biopsy and stool samples were examined for enteric pathogens and patients were evaluated for malabsorption. MEASUREMENTS AND MAIN RESULTS: Malabsorption was common in HIV-infected patients. In 15 of 38 patients mononuclear cells infected with HIV were found in the mucosa. In 15 of 25 patients there was no detectable lactase (beta-glucosidase) activity in the duodenal brush border; when measurable, lactase (beta-glucosidase) activity was decreased (P less than 0.02). Alkaline phosphatase activity was normal. Crypt depth was greater (P less than 0.05), villous surface area was slightly smaller, and mitotic figures per crypt were not different in HIV-infected patients compared with controls. Patients without additional intestinal infection had a reduced number of mitotic figures per crypt (P less than 0.05) and normal crypt depth. The reduction in mitotic figures was most pronounced in patients with mucosal HIV antigen p24. CONCLUSIONS: The HIV-infected patients with gastrointestinal symptoms show low-grade small bowel atrophy and a maturational defect in enterocytes, which may be caused exclusively by HIV. An additional intestinal infection can mask this mucosal atrophy.

Acquired Immunodeficiency Syndrome

Fungal infections during neutropenia: the role of prophylaxis.

Fungal infections are seen predominantly in patients with neoplastic diseases. Autopsy studies revealed that 30 to 50% of decreased patients with hematologic neoplasms have histopathologically documented invasive fungal infections. The rationale for fungal chemoprophylaxis is the high incidence of fungal disease in these patients (5), the high mortality (29), the difficulty in diagnosing (28), and the severe side effects of systemic antifungal therapy with amphotericin B (3). Endogenous sources such as oropharyngeal and digestive mucous membranes and exogenous pathways such as air (e.g.aspergilli) or food have to be considered. Therefore, prophylaxis has to comprise both aspects:Prevention of acquisition through nonspecific hygiene measures (5), reduction of colonization (non-absorbable antifungals or systemic chemoprophylaxis) (20). Antifungal prophylaxis of candidosis with both non- and absorbable drugs has not been convincing in terms of reduction of proven fungal infections. Prevention of aspergillosis consists mainly of the control of room air.

Agranulocytosis

Oral candidosis and its role in immunocompromised patients.

The increased incidence of invasive candidosis in numerous categories of patients, including neonates, cancer patients, AIDS patients and patients who have undergone organ transplantation, is of great concern for the physicians involved. The manifestations of candidosis are numerous, and various clinical entities such as localized and disseminated infection have to be considered separately. All types of localized candidosis per se are usually not the main cause of disseminated disease. However, spreading of the mycotic pathogens in the gastrointestinal tract could induce disseminated candidosis. Prophylactic measurements in risk patients and consequent local and, if necessary, systemic treatment is recommended in these clinical entities.

Candidiasis, Oral

Influence of ranitidine, pirenzepine, and aluminum magnesium hydroxide on the bioavailability of various antibiotics, including amoxicillin, cephalexin, doxycycline, and amoxicillin-clavulanic acid.

Two randomized double-blind crossover studies and one randomized crossover study were performed to document possible drug-drug interactions between antacids (aluminum magnesium hydroxide, 10 ml per dose for 10 doses), antimuscarinic drugs (pirenzepine, 50 mg per dose for 4 doses), and H2-blockers (ranitidine, 150 mg per dose for 3 doses) and amoxicillin (1,000 mg), cephalexin (1,000 mg), doxycycline (200 mg), and amoxicillin-clavulanic acid (625 mg). Ten healthy volunteers participated in each study. Concentrations in serum and urine were measured by bioassay, and pharmacokinetic parameters were calculated by the usual open one- or two-compartment models (statistics were determined by the Wilcoxon test). The antacid, pirenzepine, and ranitidine had no influence on the bioavailability of amoxicillin, cephalexin, and amoxicillin-clavulanic acid. Only small differences could be observed in the pharmacokinetic parameters, but they are not of therapeutic importance. However, the antacid caused a significant (P less than 0.01) reduction in the gastrointestinal absorption of doxycycline (area under the concentration-time curve, 38.6 +/- 22.7 mg.h/liter, fasting; 6.0 +/- 3.2 mg.h/liter, with antacid), resulting in subtherapeutic levels of doxycycline.

Adult

Unique aspects of quinolone pharmacokinetics.

Despite some limited differences in pharmacokinetic parameters among the newer quinolones, their pharmacology is characterised by high volumes of distribution, long elimination half-lives, good to excellent bioavailability, low protein binding, limited biotransformation and different elimination pathways (mainly through the kidneys). The unique aspects of quinolones in comparison with beta-lactams and aminoglycosides are their higher volumes of distribution, longer elimination half-lives and their intracellular high concentration, especially in phagocytic cells.

4-Quinolones