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Biomedical subjects

M Hommel

Publications and source records attributed to M Hommel.

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

A multiple antigen detection dipstick colloidal dye immunoassay for the field diagnosis of trypanosome infections in cattle.

Monoclonal antibodies (McAbs) were developed against aspartate aminotransferase purified from Trypanosoma brucei rhodesiense bloodstream form (bf) soluble extracts using a combination of anion-exchange and hydrophobic interaction chromatography. McAb 1A1 was Trypanozoon and Nannomonas specific while 2F1 was Trypanozoon bloodstream form specific. A dipstick colloidal dye immunoassay (DIA) was employed as a field diagnostic test for African trypanosome infections and designed using affinity purified polyclonal antibodies (PcAbs) raised against T. b. rhodesiense bf and the two McAbs, 1A1 and 2F1. PcAbs were adsorbed onto Palanil Red dye particles and used as dye reagents. Dipsticks were dotted with the three different antibodies, which captured trypanosomal antigens in samples tested, while the dye reagent bound to the captured antigens; the presence of coloured dots on the dipstick identified trypanosome infections. A field trial of the DIA was carried out in southeastern Uganda. A total of 1686 cattle from seven areas were bled and tested by DIA and haematocrit centrifuge technique (HCT). A total of 798 cattle (47.3%) were found to be trypanosomal antigen positive by DIA while only 162 (9.6%) were revealed to harbour trypanosomes by HCT, of which 151 (93%) were also positive by DIA.

Animals↗
PubMed1994

[Treatment of cerebral ischemia in its acute phase and prospectives].

At the acute stage of cerebral ischemia, the "therapeutic window" probably does not last more than 6-12 hours. Despite similar treatments, patients admitted in stroke specialist units are more likely to survive and to have a good functional outcome than patients treated in general wards. In most cases acute arterial hypertension should not be treated. Thrombolytic agents given within 6 hours after onset, are now under evaluation in several clinical trials. There is no scientific evidence to support the use of anti-coagulation as a curative treatment of acute cerebral ischemia; however, clinical trials remain necessary, especially in progressing stroke. Neuroprotective drugs protect neurons against the consequences of hypoxia in animals: most clinical trials with oral nimodipine led to negative results but the meta-analysis suggests that patients receiving nimodipine within 12 hours after stroke onset might have a lower mortality rate and a better functional outcome. Other clinical trials with neuroprotective drugs are currently running: anti-NMDA drugs, chlomethiazol, tirilazad, ganglioside GM 1, etc Most therapeutic agents are now under evaluation. An early admission of patients with acute stroke is required to evaluate therapeutics agents which probably cannot be effective if started more than 6-12 hours after stroke onset.

Acute Disease↗
PubMed1994

Patent foramen ovale in young stroke patients with mitral valve prolapse.

Because mitral valve prolapse and patent foramen ovale are supposed to promote stroke in young patients, we assessed the frequency of patent foramen ovale in 18 patients younger than 45 years with stroke and mitral valve prolapse diagnosed on echocardiography at the time of stroke, who were admitted to 2 university hospitals. Eleven patients were called back to hospital for contrast transthoracic and/or transesophageal echocardiography, 3 to 7 years after their initial stroke. A patient foramen ovale was found in 9 patients (50%). In 4 re-assessed patients no mitral valve prolapse was found using our present criteria. Six patients with mitral valve prolapse had a patent foramen ovale (43%). Our results suggest that mitral valve prolapse is commonly associated with patent foramen ovale in young stroke patients.

Adolescent↗
PubMed1994

Venous sinus thrombosis associated with androgens in a healthy young man.

BACKGROUND: Cerebral venous sinus thrombosis is rare and can be promoted by various conditions. We report the case of cerebral venous thrombosis in a patient using androgens. CASE DESCRIPTION: A 31-year-old man using androgens for bodybuilding was admitted for headache and vomiting. He had cerebral venous sinus thrombosis, but extensive examinations did not reveal any known cause. CONCLUSIONS: We suggest that androgens may promote cerebral venous thrombosis. The mechanisms of venous thrombosis related to androgens may be platelet activation or an increase in coagulation factors. Because androgen use may be frequent and hidden in athletes, it may be an underestimated cause of cerebral venous sinus thrombosis in the young.

Adult↗
PubMed1994

Long-term prognosis of symptomatic lacunar infarcts. A hospital-based study.

BACKGROUND AND PURPOSE: This study concerns the long-term prognosis of lacunar infarcts. METHODS: We report the analysis of our hospital-based series of 178 patients consecutively admitted for a lacunar syndrome due to a lacunar infarct diagnosed with computed tomography and magnetic resonance imaging. Demographic data, medical history, vascular risk factors, and imaging data were recorded for each patient. The follow-up was 35 +/- 22 months. RESULTS: The lacunar syndrome was pure motor hemiparesis in 69 patients (39%), ataxic hemiparesis in 45 patients (25.4%), pure sensory stroke in 15 patients (8.5%), sensorimotor stroke in 14 patients (7.9%), and miscellaneous syndrome in 34 patients (19.2%). The 4-year survival rate was 80 +/- 4% and the 4-year survival rate without recurrent stroke was 85 +/- 3.5%. Using Cox proportional-hazards analysis, the predictors of death were age (P < .02), diabetes mellitus (P < .05), and cigarette smoking (P < .05). We did not find any predictors of recurrence. After 1 year, 74% of the patients had mild or no disability. Using logistic regression analysis, the predictive factors of disability were age more than 70 years (P < .01), diabetes (P < .01), history of stroke or transient ischemic attack (P < .05), and type of lacunar syndrome (P < .01). Imaging data, number of lacunes, and presence of leukoaraiosis were not predictors of outcome. CONCLUSIONS: Our study suggests that with a high survival rate, a low recurrence rate, and a relatively good functional recovery, lacunar infarcts have a relatively favorable prognosis.

Activities of Daily Living↗
PubMed1994

[Cerebrovascular emergency units].

The first cerebrovascular emergency units were created at the end of the 1970s. Their organisation now varies greatly from one hospital to another, ranging from units equipped with intensive care facilities to the simple distinction of a team devoted to the management of this disease. Their objective is to reduce the mortality and residual handicap. They appear to achieve this objective, probably essentially because of the prevention and treatment of complications. They also have other advantages, more difficult to evaluate, attributable to the skills of the multidisciplinary team: better diagnosis, prognosis, better medical and social organisation of the patient's future in collaboration with his or her family. These centres improve the efficacy of health care systems, probably without any major increase in costs. These centres are therefore a special site for clinical research into the pathophysiology and hospital epidemiology, but especially for therapeutic trials in acute cerebral vascular accident, as a number of potentially effective molecules are available whose efficacy needs to be evaluated.

Cerebral Arterial Diseases↗
PubMed1994

[Thrombolysis].

About 65% of cerebral vascular accidents are due to occlusion of a large calibre artery, which spontaneously resolves during the hours or days following occlusion. Experimental studies have shown that neuronal death does not occur immediately. The hypothesis of thrombolysis is based on early restoration of cerebral blood flow by administration of a thrombolytic, which would facilitate neuronal recovery and reduce mortality and sequelae (efficacy hypothesis). Such early thrombolysis would not carry an excessive risk of symptomatic haemorrhage (safety hypothesis). The feasibility of thrombolysis in cerebral ischaemia is now established, but its efficacy and safety remain to be evaluated by randomised controlled clinical trials.

Brain Ischemia↗
PubMed1993

Use of immunoplot analysis for the identification of immunodominant non-variant antigens of Trypanosoma brucei rhodesiense.

The application of the 'immunoplot' technique to the analysis of a complex series of immunoblots is described. A number of isolates of Trypanosoma brucei rhodesiense blood forms from Uganda, Kenya and Zambia were separated by SDS-PAGE under reducing and non-reducing conditions and transferred by immunoblotting onto nitrocellulose paper. The separated antigens from each isolate were then probed with sera from European and endemic controls, and a large panel of sera from confirmed trypanosomiasis patients. The resulting series of immunoblots was examined by the 'immunoplot' technique, which involves comparing frequencies of recognition of each band by the sera of controls and patients. A number of antigens of possible diagnostic interest were identified; a bad of 37/38 kDa was found to be recognised with high frequency (> 55%) by the sera of patients and virtually not at all by control sera under both reducing and non-reducing conditions. When this band was combined with one of the other frequently recognised bands, recognition by patient sera was raised to 92% (reduced) and 76% (non-reduced). This did not appear to be isolate-specific. The 'immunoplot' technique has potential for further development and wider use in immunoepidemiology and immunodiagnostic research.

Animals↗
PubMed1993

Amplification of cytoadherence in cerebral malaria: towards a more rational explanation of disease pathophysiology.

Cerebral malaria in man and in mice is the consequence of a cascade of events, involving the production of toxins by the parasite and cytokines by the host, and eventually leading to the amplification of the expression of the receptors for cytoadherence on brain capillary endothelial cells. Variations in the intrinsic characteristics of parasite isolates or the genetic make-up of the host and the degree of antimalarial immunity can modulate this sequence of events. A working hypothesis is proposed in which two features of the parasite, the ability to cytoadhere and to produce toxins, are clearly dissociated and where the amplification of cytoadherence receptors is considered crucial. This hypothesis, illustrated by new data from human malaria and rodent models, suggests that cerebral malaria may occur when these features occur together during an infection, while not necessarily within the same parasite clone.

Animals↗
PubMed1993

Rationale for testing thrombolysis in acute ischaemic stroke. MAST Group.

Stroke is an important health problem in developed countries, being a common cause of death and disability. Prognosis is poor for hospitalised stroke patients, with a 30-day mortality rate of 20-30%, and 30% of the survivors remaining severely disabled. Based on results from experimental animal studies it is thought that early intervention will improve the patients' prognosis. Thrombolytic therapy has been shown to reduce mortality in patients with acute myocardial infarction, and several trials aim to assess its efficacy in patients with acute cerebral infarction. Although many clinical trials have been performed to address this problem, none have provided a clear answer, either because the sample size was insufficient, or by modern standards, the methodology used was not adequate. The Multicenter Acute Stroke Trials (MAST) has been designed to assess the safety and efficacy of thrombolytic therapy with streptokinase for this indication.

Animals↗
PubMed1993

[Jugular foramen syndrome caused by herpes zoster].

Multiple cranial nerve palsies frequently occur in patients with cephalic zoster. Nevertheless, to our knowledge, involvement of the glossopharyngeal (IXth), vagus (Xth) and accessory (XIth) nerves has not yet been reported. We report a case of jugular foramen syndrome with palatolaryngeal herpetic eruption, aseptic meningitis and a high level of serum antibody to varicella-zoster virus.

Accessory Nerve↗
PubMed1993

[Association of lacunar infarction and intracerebral hematoma].

Five out of 160 cases of lacunar infarcts were preceded or followed by intracerebral hemorrhage. Four patients were hypertensive. This association raises the question of a common risk factor in lacunar infarct and intracranial hemorrhage. The possibility that these different stroke types may be due to the same arteriolar pathology is discussed.

Aged↗