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Biomedical subjects

M Schneemann

Publications and source records attributed to M Schneemann.

At least 19 recordsLinked to original sources
PubMed2004

Life-threatening envenoming by the Saharan horned viper (Cerastes cerastes) causing micro-angiopathic haemolysis, coagulopathy and acute renal failure: clinical cases and review.

BACKGROUND: The desert horned vipers (Cerastes cerastes and C. gasperettii) are the most familiar snakes of the great deserts of North Africa and the Middle East, including the plains of Iraq. They are responsible for many human snake bites. In Western countries, they are popular among exotic-snake keepers. AIM: To investigate mechanisms of life-threatening envenoming and treatment. DESIGN: Clinical investigation. METHODS: Clinical and laboratory studies with measurement of serum venom antigen concentrations by enzyme immunoassay. RESULTS: Two men bitten while handling captive Saharan horned vipers (Cerastes cerastes) in Europe developed extensive local swelling and life-threatening systemic envenoming, characterized by coagulopathy, increased fibrinolysis, thrombocytopenia, micro-angiopathic haemolytic anaemia and acute renal failure. The clinical picture is explicable by the presence in C. cerastes venom of several thrombin-like, Factor-X-activating, platelet-aggregating, haemorrhagic and nephrotoxic components. In one case, prophylactic use of subcutaneous epinephrine may have contributed to intracranial haemorrhage. The roles in treatment of heparin (rejected) and specific antivenom (recommended) are discussed. DISCUSSION: Cerastes cerastes is capable of life-threatening envenoming in humans. Optimal treatment of envenoming is by early administration of specific antivenom, and avoidance of ineffective and potentially-dangerous ancillary methods.

Acute Kidney Injury↗
PubMed2003

Rapid detection of pathogenic fungi from clinical specimens using LightCycler real-time fluorescence PCR.

In the study presented here a LightCycler real-time PCR system was used for the diagnosis of fungal infections from clinical tissue samples. Nine specimens were investigated from six patients with suspected or proven invasive fungal infections. Seven of nine samples were positive in a broad-range fungal PCR assay. In four samples, Aspergillus fumigatus was detected both by a species-specific hybridization assay as well as by sequencing of amplification products. In addition, the broad-range fungal PCR assay and PCR sequencing detected and identified, respectively, the following organisms in the specimens noted: Candida albicans in a culture-negative liver biopsy, Histoplasma capsulatum in a bone marrow sample, and Conidiobolus coronatus in a facial soft tissue specimen. Real-time PCR is a promising tool for the diagnosis of invasive fungal infections in human tissue samples and offers some advantages over culture methods, such as rapid analysis and increased sensitivity.

Aspergillus fumigatus↗
PubMed2003

[Rare cause of chronic abdominal pain: retractile mesenteritis].

HISTORY AND ADMISSION FINDINGS: A 69-year-old man had a history of chronic abdominal pain and intermittent fever for more than 10 years. Due to acute epigastric pain and intermittent fever with night sweat for one week he was admitted for further investigation. On physical examination there was tenderness in the right upper and lower epigastrium without a palpable mass. INVESTIGATIONS: Laboratory figures showed signs of inflammation with a CRP of 103 mg/l. Leucocyte counts were normal without left shift. CT and MRI scans showed a sharp-edged mass of 10 x 8 cm in diameter in the retroperitoneal area with big vessels running through it. Laparoscopic biopsy confirmed the suspected diagnosis of retractile mesenteritis. TREATMENT AND COURSE: Under therapy with oral progesterone (Utrogestan 1 x 100 mg/d) and prednisone (Prednison 1 x 50 mg/d) there was fast symptomatic relief. A CT scan 2 months after initial diagnosis showed clear regression of the tumor. CONCLUSION: Retractile mesenteritis is a rare cause of chronic abdominal pain with variable symptoms. Its aetiology is unknown. In case of bowel ischemia a surgical approach is preferred, milder forms may be treated with immunosuppressive agents as well as oral progesterone. Progesterone has exhibited positive effects on fatty tissue with successful treatment in desmoid tumors and retroperitoneal fibrosis. Here in we could demonstrate its safe and efficient use in a patient with retractile mesenteritis.

Abdominal Pain↗
PubMed2003

Marginal and subgingival plaque--a natural habitat of Tropheryma whipplei?

BACKGROUND: DNA of Tropheryma whipplei, the etiologic agent of Whipple's disease, has recently been detected in the saliva of healthy subjects. In this pilot study we searched for the habitat of T. whipplei within the oral cavity. MATERIALS AND METHODS: Samples from different oral sites were obtained from periodontically healthy volunteers, patients with progressive periodontitis and Chinese subjects with necrotizing ulcerative gingivitis or gingivitis. Quantitative real-time PCR was performed using T. whippleispecific primers, human beta-globin-specific primers to control for tissue DNA extraction and PCR reaction and broad-range eubacterial primers to control for bacterial DNA extraction. T. whipplei specificity of multiple amplicons was confirmed by sequencing. The detection limit of the method was 10 ag of T. whipplei DNA, corresponding to one to five bacteria under reference assay conditions. RESULTS: T. whipplei was found in the oral cavity of four out of ten healthy individuals from hospital staff and in three out of nine periodontitis patients, but in none of the individuals from China. All positive samples derived from subgingival and gingival sulcus plaque containing between 10(3) and 5 x 10(5) cells ml(-1) of plaque suspension, whereas saliva, smooth surface plaque and samples from the tongue or cheeks were negative. CONCLUSION: Our results suggest that T. whipplei colonizes the human body via the oral cavity and that bacterial plaques of the gingival crevice and the gingival sulcus/pocket may serve as a natural primary habitat.

Actinomycetales↗
PubMed2001

[Fatal brain edema after ingestion of ecstasy and benzylpiperazine].

HISTORY AND ADMISSION FINDINGS: A 23-year-old woman was hospitalized with headache, malaise and somnolence 11 hours after ingestion of A2 (benzylpiperazine), 7 hours after ingestion of ecstasy (MDMA), and large volume of fluids. On admission she had bradycardia (heart rate 48/min), hypertension (blood pressure 154/95 mm Hg), and reduced consciousness with diminished tendon reflexes and non-reacting pupils (Glasgow Coma Score 6). INVESTIGATIONS: Serum sodium was markedly decreased (115 mmol/l [normal 135-145]) with low plasma osmolality (246 mosm/kg [normal 280-300]). Other laboratory findings were within normal limits. TREATMENT AND COURSE: The patient had severe hypervolaemic hypotonic hyponatraemia. 40 minutes after admission she seized twice and was intubated. Brain CT scan showed massive cerebral oedema with beginning tonsillar herniation. Serum sodium concentration returned to normal within 38 hours, but the patient deteriorated neurologically with increasing tonsillar herniation detected in a second brain CT scan. The patient died 57 hours after admission. CONCLUSION: 13 cases of MDMA-associated severe hyponatraemia are reported. Intake of fluids after MDMA ingestion may lead to potentially fatal hypervolaemic hypotonic hyponatraemia with cerebral oedema. Symptoms appear about 8 hours (range 4-18) after MDMA ingestion. Even low doses of MDMA and fluids may lead to a serious outcome. The only risk factor is female gender. Measurement of serum sodium and brain CT scan is recommended in all patients with altered mental status after MDMA consumption.

Adult↗
PubMed2001

Reactive hypoglycaemia due to late dumping syndrome: successful treatment with acarbose.

Reactive hypoglycaemia is a rare disease which occurs postprandially in everyday life involving blood glucose levels below 2.5 to 2.8 mmol/l. We report on a 66-year-old patient who developed symptomatic reactive hypoglycaemia due to late dumping syndrome 10 years after oesophagectomy with cervical anastomosis. A 75 g sucrose load revealed a plasma glucose level of 9.4 mmol/l after one hour, followed by symptomatic hypoglycaemia with a plasma glucose level of 1.8 mmol/l after three hours. Concomitantly, high concentrations of insulin (3216 pmol/l at a glucose level of 9.4 mmol/l and 335 pmol/l at a glucose level of 1.8 mmol/l) and glucagon-like peptide 1 (GLP-1) (375 pmol/l at a glucose level of 9.4 mmol/l and 85 pmol/l at a glucose level of 1.8 mmol/l) were measured. While the patient was under treatment with acarbose, another sucrose load did not provoke symptomatic hypoglycaemia (plasma glucose nadir of 4.6 mmol/l after two hours). Insulin and GLP-1 levels increased much less, to peak levels of 375 pmol/l and 75 pmol/l respectively, after one hour when plasma glucose was 6.8 mmol/l. We conclude that in patients with reactive hypoglycaemia due to gastrointestinal surgery, acarbose decreases rapid glucose absorption associated with hyperglycaemia and GLP-1 secretion, and thus diminishes excessive insulin release. Acarbose is therefore a successful treatment modality for reactive hypoglycaemia due to late dumping syndrome.

Acarbose↗
PubMed2001

Fatal hepatoxicity secondary to nimesulide.

This report describes a 57-year-old female patient with chronic lumbago, who died from the sequelae of acute liver failure induced by nimesulide medication. Nimesulide is a non-steroidal anti-inflammatory drug (NSAID) which preferentially inhibits cyclo-oxygenase 2 and has been associated with a total of 13 reported cases of severe liver injury including our case. On the basis of the literature reports, the following features of nimesulide-associated hepatotoxicity were identified: female sex (84% of cases), age (mean age 62 years), jaundice as a primary manifestation (90%) and the absence of peripheral blood eosinophilia. The average duration of therapy of the published cases was 62 days (range 7-180 days). Based on spontaneous reports to the World Health Organization, nimesulide induces a high proportion of severe adverse hepatic reactions compared with other NSAIDs registered in Switzerland. Hepatotoxicity thus represents an important risk factor of nimesulide usage.

Anti-Inflammatory Agents, Non-Steroidal↗
PubMed1998

Junctional adhesion molecule, a novel member of the immunoglobulin superfamily that distributes at intercellular junctions and modulates monocyte transmigration.

Tight junctions are the most apical components of endothelial and epithelial intercellular cleft. In the endothelium these structures play an important role in the control of paracellular permeability to circulating cells and solutes. The only known integral membrane protein localized at sites of membrane-membrane interaction of tight junctions is occludin, which is linked inside the cells to a complex network of cytoskeletal and signaling proteins. We report here the identification of a novel protein (junctional adhesion molecule [JAM]) that is selectively concentrated at intercellular junctions of endothelial and epithelial cells of different origins. Confocal and immunoelectron microscopy shows that JAM codistributes with tight junction components at the apical region of the intercellular cleft. A cDNA clone encoding JAM defines a novel immunoglobulin gene superfamily member that consists of two V-type Ig domains. An mAb directed to JAM (BV11) was found to inhibit spontaneous and chemokine-induced monocyte transmigration through an endothelial cell monolayer in vitro. Systemic treatment of mice with BV11 mAb blocked monocyte infiltration upon chemokine administration in subcutaneous air pouches. Thus, JAM is a new component of endothelial and epithelial junctions that play a role in regulating monocyte transmigration.

Amino Acid Sequence↗
PubMed1997

Crucial role of interferon consensus sequence binding protein, but neither of interferon regulatory factor 1 nor of nitric oxide synthesis for protection against murine listeriosis.

Listeria monocytogenes is widely used as a model to study immune responses against intracellular bacteria. It has been shown that neutrophils and macrophages play an important role to restrict bacterial replication in the early phase of primary infection in mice, and that the cytokines interferon-gamma (IFN-gamma) and tumor necrosis factor-alpha (TNF-alpha) are essential for protection. However, the involved signaling pathways and effector mechanisms are still poorly understood. This study investigated mouse strains deficient for the IFN-dependent transcription factors interferon consensus sequence binding protein (ICSBP), interferon regulatory factor (IRF) 1 or 2 for their capacity to eliminate Listeria in vivo and in vitro and for production of inducible reactive nitrogen intermediates (RNI) or reactive oxygen intermediates (ROI) in macrophages. ICSBP-/- and to a lesser degree also IRF2-/- mice were highly susceptible to Listeria infection. This correlated with impaired elimination of Listeria from infected peritoneal macrophage (PEM) cultures stimulated with IFN-gamma in vitro; in addition these cultures showed reduced and delayed oxidative burst upon IFN-gamma stimulation, whereas nitric oxide production was normal. In contrast, mice deficient for IRF1 were not able to produce nitric oxide, but they efficiently controlled Listeria in vivo and in vitro. These results indicate that (a) the ICSBP/IRF2 complex is essential for IFN-gamma-mediated protection against Listeria and that (b) ROI together with additional still unknown effector mechanisms may be responsible for the anti-Listeria activity of macrophages, whereas IRF1-induced RNI are not limiting.

Adoptive Transfer↗
PubMed1997

Nitrite generation in interleukin-4-treated human macrophage cultures does not involve the nitric oxide synthase pathway.

The search continues for high-output nitric oxide biosynthesis in human macrophages analogous to murine phagocytes. Recently, generation of nitrite in culture supernatants of human macrophages exposed to interferon-gamma and interleukin-4 (IFN-gamma/IL-4) was reported. The present study reproduces these findings and shows that L-arginine is not consumed and L-citrulline is not produced during this process. Furthermore, the biosynthesis of the obligatory cofactor tetrahydrobiopterin is not coinduced. These biochemical data provide support against a nitric oxide synthase contribution to nitrite accumulation. Nitrite was generated from nitrate salts even in cell-free media. Nitric oxide synthase activity but not nitrate reduction depended on molecular oxygen. Nitrite accumulation in experiments with IFN-gamma/IL-4 in human monocytes appears to be an in vitro artifact produced by nitrate-reducing activities contained in cytokine preparations.

Amino Acids↗
PubMed1997

Inhalation of the nitric oxide synthase cofactor tetrahydrobiopterin in healthy volunteers.

Pulmonary endothelial dysfunction is the hallmark of acute lung injury. Impaired pulmonary endothelial nitric oxide (NO) production in this event has been described. Tetrahydrobiopterin (BH4) is an essential cofactor for NO synthase and modulator of its activity. At high local concentrations, BH4 provokes local vasodilation in vivo in healthy individuals. At lower concentrations, BH4 selectively and locally restores disturbed NO-dependent vasodilation in patients with endothelial dysfunction. In this preliminary study, we therefore investigated the feasibility of BH4 inhalation in five healthy human volunteers. Inhalation of buffered, aqueous BH4-dihydrochloride solution was well tolerated; despite the buffer, BH4 stability was completely preserved. Resorption of inhaled BH4 was demonstrated by significantly increased BH4 levels in plasma and urine. Inhaled BH4 did not alter pulmonary function and had no effect on systemic hemodynamic values. Our data demonstrate that inhalation is a novel method for local BH4 administration, offering a basic therapeutic tool for investigation of restoration of impaired NO-dependent vasodilation due to pulmonary endothelial dysfunction.

Administration, Inhalation↗
PubMed1996

Comparison of the antimicrobial activity of deactivated human macrophages challenged with Aspergillus fumigatus and Listeria monocytogenes.

The anticonidial activity of human monocytes deactivated by cytokines interleukin (IL)-4 and IL-10 and the hormone dexamethasone was studied and compared with antilisterial activity. Dexamethasone had the largest effect on the anticonidial activity and suppressed germination-inhibiting activity and elimination of ingested spores by macrophages more than the cytokines did. Maximally active concentrations of IL-10 had a similar but significantly smaller deactivating effect. IL-4, in contrast to IL-10 and dexamethasone, did not reduce anticonidial activity. However, IL-4 and IL- 10 were equally potent in deactivating human macrophages against Listeria monocytogenes, whereas dexamethasone was significantly less potent in the Listeria model. These observations indicate that all three mediators lessen antimicrobial activity but that this effect depends on the test organism studied and is apparently mediated through regulation of different antimicrobial systems operating against a particular microorganism.

Aspergillus↗