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Biomedical subjects

C Ruef

Publications and source records attributed to C Ruef.

At least 73 records · Page 4Linked to original sources
PubMed1994

[Meningitis in adults].

The clinical presentation of a 38-year-old female patient with acute onset of fever and decreased level of consciousness is described. The clinical reasoning concerning differential diagnosis, therapeutic options, workup of the patient and possible bacterial etiologies, which is usually part of the physician's initial encounter with the patient, is included in the case presentation. This summary of a workshop offers a concise review of clinical aspects of bacterial meningitis.

Adult↗
PubMed1993

[Disseminated tuberculosis with a multiresistant strain of Mycobacterium tuberculosis in an HIV-infected Swiss male].

Multidrug-resistant M. tuberculosis in HIV-infected people has not yet been reported in Switzerland, and there have been no nosocomial epidemics as they have recently occurred in the USA. We present the case of a 38-ear-old HIV-infected man who developed disseminated tuberculosis as AIDS-defining disease. Initially he was treated with isoniazid, pyrazinamide and rifampin. Due to the emergence of resistance to isoniazid and streptomycin, ethambutol was added for one month. Later the therapy was changed back to the initial three drugs. The patient responded well to this therapy, but five months later developed a relapse. In addition to the originally diagnosed double-drug resistance, a reduced susceptibility to rifampin appeared. Ethambutol, ciprofloxacin and amikacin were added to the original three-drug regimen. This resulted in rapid clinical improvement, although sputum cultures remained positive for M. tuberculosis two months later. This isolate was resistant to pyrazinamide. For that reason pyrazinamide was replaced by clofazimine. 14 months after diagnosis the patient died of hepatic failure. Because there was a delay in isolation of one week, 37 potentially exposed health care workers were tested by the Mantoux skin test. No conversions were observed. This case report demonstrates that tuberculosis in HIV-infected patients in Switzerland may be caused by multidrug-resistant M. tuberculosis. We propose that until the results of a susceptibility assay are known, a four-drug combination should be used initially in this patient group.

AIDS-Related Opportunistic Infections↗
PubMed1993

[Diagnosis and therapy of community-acquired pneumonia].

Whereas the diagnosis of community-acquired pneumonia usually is straightforward, in many cases the exact etiology is difficult or impossible to determine. The clinician must have a management strategy for this illness which is not dependent upon precise microbiological diagnosis in each case. Therefore, understanding of the spectrum of community-acquired pneumonias and awareness of the possible pathogens in specific clinical settings is crucial for the choice of the most appropriate antimicrobial therapy. The factors influencing prognosis of community-acquired pneumonia are important for the decision as to which patients should be hospitalized.

Anti-Bacterial Agents↗
PubMed1993

Regulation of cytokine secretion by cystic fibrosis airway epithelial cells.

Chronic airway inflammation is an important feature of cystic fibrosis (CF), markedly influencing morbidity and mortality. We wanted to assess the contribution of the respiratory epithelium in the mediation of local inflammatory events, and, more particularly, its regulating role through cytokine secretion. We have studied the regulation of interleukin-6 and 8 (IL-6 and IL-8) production by the SV40 transformed airway epithelial cell line JME/CF15 (homozygous for the deletion of Phe 508). We show that unstimulated JME/CF15 cells secrete IL-6 and IL-8. Neutrophil chemotactic activity (NCA) is detected in supernatants. The secretion of IL-6 and IL-8 is increased following stimulation of the JME/CF15 cells by IL-1 beta and neutrophil elastase. Lipopolysaccharide and granulocyte macrophage colony stimulating factor (GM-CSF) have no effect on secretion of IL-6 or IL-8. Neutrophil elastase inactivates recombinant human IL-6 at 37 degrees C in vitro, but has no effect at 4 degrees C, suggesting a proteolytic effect of elastase on IL-6. IL-8 activity remains preserved, even after prolonged exposure to elastase. Our data suggest that the airway epithelium may play an active role in the mediation of neutrophil chemotaxis. Local production of IL-8 in response to elastase and IL-1 beta, together with the inactivation of the anti-inflammatory protein IL-6, may result in a significant upregulation of airway inflammation in cystic fibrosis.

Cells, Cultured↗
PubMed1992

[Boutonneuse fever in Switzerland: apropos of a case report].

The history and clinical presentation of Mediterranean spotted fever in a 72-year-old male patient with polycythemia vera are described. The patient presented soon after arrival in Bordeaux (France) with fever, arthralgia and an erythematous maculopapular skin rash involving the palms and foot soles. The clinical course was complicated by pulmonary involvement resulting in dyspnea and hypoxemia. The patient denied tick bite but had contact with a dog. Antibiotic therapy with doxycycline resulted in rapid improvement of all clinical findings. A significant rise in antibody titer against Rickettsia conorii confirmed the diagnosis. The case is discussed in relation to other published cases in Switzerland and illustrates that this infection can be acquired outside an endemic area.

Aged↗
PubMed1992

Mesangial cell-matrix interactions. Effects on mesangial cell growth and cytokine secretion.

Glomerulonephritis (GN) results in proliferation of mesangial cells (MC), infiltration of inflammatory cells, and accumulation of extracellular matrix (ECM) proteins in the mesangium. Locally secreted cytokines may stimulate MC growth or the secretion of inflammatory mediators by MC. Interleukin-6 (IL-6) may be an autocrine cofactor in the pathogenesis of mesangioproliferative GN. We studied the regulation of IL-6 secretion by MC in response to MC-derived cytokines and ECM proteins. IL-6 secretion is stimulated in a dose-dependent manner by IL-1 alpha, TNF-alpha, and PDGF. Constitutive and LPS-induced release of IL-6 by MCs is reduced on collagen type I (coll I) compared-with uncoated surfaces. IL-6 release on collagen type IV (coll IV), however, is enhanced. In addition, MC on coll I exhibit a sixfold higher growth rate than cells on uncoated surfaces. The reduction of cytokine secretion in parallel with the stimulation of MC growth by coll I suggests that exposure to coll I may result in a change from secretory to proliferative phenotype in vitro.

Animals↗
PubMed1991

[GM-CSF and G-CSF: cytokines in clinical application].

Leukopenia or pancytopenia as a result of bone marrow dysfunction are manifestations of various diseases or complications of therapeutic regimens. The spectrum of diseases associated with leukopenia is wide and includes congenital as well as acquired neutropenias secondary to conditions such as myelodysplastic syndromes, AIDS, malignant tumors with or without chemotherapy-enhanced neutropenia, bone marrow transplantation or therapeutic or accidental radiation. The morbidity and mortality of infectious diseases is greatly enhanced during neutropenic phases. Over the last few years attempts have been made to shorten the duration and lessen the severity of neutropenia in patients with the above conditions by administration of Granulocyte Macrophage Colony Stimulating Factor (G-CSF). Both cytokines were successfully tested in phase I and II trials. Treatment with GM-CSF or G-CSF results in a dose-dependent increase of the neutrophil count. GM-CSF also increases the number of eosinophils and monocytes in peripheral blood. The effect of both cytokines on the neutrophil count is transient as long as the underlying disease persists. This prompted the institution of maintenance therapy, which has been successfully used with either cytokine. Long-term treatment is usually well tolerated and results in a reduction in the frequency of infections as well as in the duration of antibiotic treatments. Side effects of GM-CSF or G-CSF are usually mild and include fever, myalgia, bone pain, and erythema. A number of patients developed dyspnea, hypotension, sweating, flushing and erythema after the first dose of GM-CSF in each treatment cycle. This first-dose reaction occurs more frequently after intravenous than reactions were reported with G-CSF. Some patients with myelodysplastic syndrome progressed to acute myeloic leukemia during or after treatment with GM-CSF or G-CSF. Most of these patients presented with an increased fraction of blasts in the bone marrow, which preceded the treatment with the colony stimulating factors. Since GM-CSF and possibly G-CSF may increase the risk of developing acute leukemia in patients with myelodysplastic syndrome, it appears prudent to limit the use of these cytokines in patients with this disease. The subcutaneous route of administration appears to be preferable to intravenous administration, since the incidence and severity of side effects are reduced. While many questions concerning dosage, long-term therapy and combination therapy still remain unanswered, the information presented in this review concerning the clinical use of these cytokines warrants an optimistic outlook.

Anemia, Aplastic↗
PubMed1991

Interleukin-6 expression in primary macrophages infected with human immunodeficiency virus-1 (HIV-1).

We have investigated the effects of human immunodeficiency virus type-1 (HIV-1) infection on constitutive and lipopolysaccharide (LPS)-induced expression of interleukin-6 (IL-6) in cultured blood monocyte-derived macrophages. Highly productive and cytopathic infection of macrophages was established with the macrophage-tropic HIV-1 BaL strain. On Days 14-28 post infection, infected and mock-infected cells were activated with LPS or control medium for 6-24 hours before harvesting culture supernatants and cellular RNA. IL-6 bioactivity in culture supernatants was measured with the IL-6-dependent B9 cell line. IL-6 mRNA levels were quantitated by Northern blot analysis with scanning densitometry. In the absence of LPS activation, IL-6 activity was near or below the limit of detection in supernatants from both infected and uninfected cultures. Similarly, without LPS stimulation, IL-6 mRNA was not detectable in either infected or uninfected macrophages. After activation with LPS, marked increases in IL-6 mRNA levels and supernatant bioactivity were evident in both infected and uninfected cultures, but the response to LPS was consistently greater in infected macrophages. LPS-induced IL-6 mRNA levels and supernatant bioactivity were 7.4- and 4.4-fold higher, respectively, in infected compared with uninfected macrophages (n = 5, p less than .05). These studies demonstrate that highly productive HIV-1 infection does not increase constitutive IL-6 expression in macrophages, but does prime macrophages for an augmented IL-6 response to LPS. These findings may help define the mechanisms responsible for increased IL-6 production in patients with HIV-1 infection.

Cells, Cultured↗
PubMed1990

Interleukin 6 is an autocrine growth factor for mesangial cells.

Interleukin 6 (IL-6) induces the acute phase response, differentiation of B cells, proliferation of T cells, thymocytes, hematopoietic progenitors, hybridoma and plasmacytoma cells. Monocytes, T cells, fibroblasts, epithelial and endothelial cells secrete IL-6. Since IL-6 responsive cell-types may participate in the pathogenesis of glomerular inflammation, we studied the secretion of IL-6 by rat MCs, using the IL-6 dependent hybridoma cell line B9. The results of our studies indicate that MCs secrete IL-6 with a molecular weight of 17-42 kDa and isoelectric point of 4.0 to 5.3 MC-IL-6 activity could be blocked by a polyclonal antimurine-IL-6 antibody. MC express IL-6 mRNA as determined by Northern blot. Furthermore, our data demonstrate that IL-6 acts as an autocrine growth factor for MC. Incubation of subconfluent MC with recombinant IL-6 results in a dose-dependent increase of 3H-thymidine incorporation and number of MCs. Moreover, reverse phase HPLC fractions of MC-CM containing IL-6 activity increase 3H-thymidine incorporation by MC. In addition to its possible paracrine role in mediating the immune response in the glomerulus, MC-IL-6 may also be one of the autocrine signals leading to mesangial cell proliferation in vivo.

Animals↗
PubMed1989

Aeromonas hydrophila infection associated with the use of medicinal leeches.

The use of medicinal leeches (Hiruda medicinalis) is becoming more common after plastic surgery to control venous congestion of skin grafts. We describe a patient with Aeromonas hydrophila infection whose graft was treated with medicinal leeches. The infection required systemic antibiotic therapy. A. hydrophila is the predominant bacterial flora in the gut of the leech, where it plays an essential role for the animal in the digestion of blood. The potential for A. hydrophila wound infection, and appropriate antibiotic prophylaxis of the leech or patient, should be considered when medicinal leeches are used.

Aeromonas↗
PubMed1989

Mucocutaneous lymph node syndrome (Kawasaki syndrome) mimicking a suppurative parapharyngeal space infection. Case report and review of the literature.

A six-year-old girl presented with fever, trismus and a very tender, enlarged submandibular mass. CT-scanning showed a right parapharyngeal mass and enlarged cervical nodes in the posterior triangle. Surgical exploration of the area failed to reveal an abscess. Subsequently the clinical criteria for the diagnosis of Kawasaki syndrome were met. This unusual presentation is compared with previously reported cases in the literature.

Child↗
PubMed1988

[Campylobacter jejuni: sepsis and meningitis in an adult without risk factors].

A case of Campylobacter jejuni meningitis with associated septicemia and positive stool culture in a normal host is presented. Clinical findings, course of the illness and serologic data are compared with data from the literature. The possibility of infection due to a serum-resistant strain of Campylobacter jejuni is raised. Retrospective analysis of immunity revealed normal humoral and cellular immunity in a healthy patient one year later.

Aged↗