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Biomedical subjects

M Hauser

Publications and source records attributed to M Hauser.

At least 73 records · Page 4Linked to original sources
PubMed1998

Linkage of adhesion, filamentous growth, and virulence in Candida albicans to a single gene, INT1.

Adhesion and the ability to form filaments are thought to contribute to the pathogenicity of Candida albicans, the leading cause of fungal disease in immunocompromised patients. Int1p is a C. albicans surface protein with limited similarity to vertebrate integrins. INT1 expression in Saccharomyces cerevisiae was sufficient to direct the adhesion of this normally nonadherent yeast to human epithelial cells. Furthermore, disruption of INT1 in C. albicans suppressed hyphal growth, adhesion to epithelial cells, and virulence in mice. Thus, INT1 links adhesion, filamentous growth, and pathogenicity in C. albicans and Int1p may be an attractive target for the development of antifungal therapies.

Animals↗
PubMed1998

Low specificity of the bacterial index for the diagnosis of bacterial pneumonia by bronchoalveolar lavage.

The bacterial index (BI) as defined by the sum of log10 colony-forming units (cfu) of microorganisms per milliliter of bronchoalveolar lavage (BAL) fluid, i.e., a multiplication of the single cfu/ml, has been used to distinguish between polymicrobial pneumonia (BI> or =5) and colonization (BI<5). Since many false-positive results are to be expected using this parameter, the diagnostic value of the BI was studied prospectively by obtaining bacteriologic cultures of BAL fluid in 165 consecutive unselected patients. In 27 cases the diagnosis of bacterial pneumonia was established on clinical criteria. In 133 patients pneumonia could be excluded, and in five patients the diagnosis remained unclear. Using a cut-off of > or = 10(5) cfu/ml BAL fluid, sensitivity and specificity for the diagnosis of pneumonia were 33% (9/27) and 99% (132/133), respectively. Sensitivity was mainly influenced by prior treatment with antibiotics, being 70% (7/10) in untreated and 12% (2/17) in treated patients. Applying the BI methodology at a cut-off of > or =5, however, resulted in an unacceptably high rate of 16 additional false-positive results, thus lowering the specificity to 87% (116/133; P<0.0001) while increasing the sensitivity to only 41% (11/27; P = 0.77). In conclusion, given the high rate of false-positive results, the methodology of the BI is of doubtful value for the diagnosis of bacterial pneumonia by BAL in an unselected patient group. By applying the absolute number of cfu/ml BAL fluid, however, positive bacteriologic cultures of BAL fluid are highly specific for the diagnosis of pneumonia. Their sensitivity is limited by previous antibiotic therapy.

Adolescent↗
PubMed1998

Myocardial blood flow and coronary flow reserve late after anatomical correction of transposition of the great arteries.

OBJECTIVES: Myocardial blood flow (MBF) in children late after arterial switch operation (ASO) was investigated quantitatively by positron emission tomography (PET). BACKGROUND: In children with transposition of the great arteries (TGA), ASO is widely accepted as the management of choice. The long-term patency of coronary arteries after surgical transfer to the neo-aorta, however, remains a concern. METHODS: Twenty-two normally developed, symptom-free children were investigated by PET with nitrogen-13 ammonia at rest and during adenosine vasodilation 10+/-1 years after ASO. A subgroup of 15 children (9+/-1 years; group A) had simple TGA and underwent ASO within 20 days after birth while 7 (13+/-3 years; group B) had complex TGA and underwent ASO and correction of associated anomalies later after birth. Ten young, healthy adults (26+/-6 years) served as the control group. RESULTS: Resting MBF was not different between groups. After correction for the rate-pressure product as an index of cardiac work, younger children of group A had significantly higher MBF at rest compared to healthy adults (102+/-29 vs. 77+/-6 ml/100 g/min; p = 0.012) while flow in group B was not different from the other groups (85+/-22 ml/100 g/min; p = NS). Hyperemic blood flows were significantly lower in both groups after ASO compared to normals (290+/-42 ml/100 g/min for group A, 240+/-28 for group B, 340+/-57 for normals; p < 0.01); thus, coronary flow reserve was significantly lower in both groups after ASO compared to healthy adults (3.0+/-0.6 for group A, 2.9+/-0.6 for group B, 4.6+/-0.9 for normals; p < 0.01). CONCLUSIONS: Blood flow measurements suggest decreased coronary reserve in the absence of ischemic symptoms in children late after arterial switch repair of TGA. The global impairment of stress flow dynamics may indicate altered vasoreactivity; however, the prognostic significance of these findings needs to be determined.

Adolescent↗
PubMed1998

Infrainguinal aneurysm formation in arterialized autologous saphenous vein grafts.

True aneurysm formation in arterialized autologous veins is an unusual complication. We studied a patient with 2 aneurysms occurring in the mid and distal portion of an in situ femoropopliteal bypass. The first aneurysm led to graft occlusion 4 years after the primary intervention, requiring replacement of the ectatic graft segment. The graft was still patent when the patient was examined 7 years after the primary intervention and 3 years after the first aneurysm. In the mid portion of the graft, a true aneurysm measuring 5 by 8 cm had developed. The aneurysm was replaced by a reversed segment of the contralateral greater saphenous vein. Recovery was uneventful. Advanced atherosclerotic changes with extensive intimal fibroplasia, subendothelial cholesterol deposits, and ulcerations were revealed by means of histopathology of the aneurysm wall. Atherosclerosis is considered to be the main cause of aneurysm formation in vein grafts, but a review of the literature suggests the additional etiopathogenic factors should be further investigated.

Aneurysm↗
PubMed1998

Sudden death 10 years after patch aortoplasty for coarctation.

A 25-year-old man died 10 years after a Dacron patch was used to repair a coarctation of the aorta. Death was due to rupture of an unrecognized aneurysm at the site of the patch. After the initial operation at the age of 15 years, there had been no signs of residual or recurrent obstruction. He had no evidence of hypertension and was discharged some years later from regular hospital follow-up to the care of his general practitioner. We strongly recommend that patients who have undergone repair of aortic coarctation by patch aortoplasty should have lifelong follow-up in cardiac units with imaging facilities for monitoring aortic dilation. We would now recommend surgical intervention in the presence of progressive aortic dilation.

Adult↗
PubMed1998

Established acute respiratory distress syndrome: benefit of corticosteroid rescue therapy.

UNLABELLED: The mortality of the acute respiratory distress syndrome (ARDS) is still very high. There is some evidence based on case series suggesting that corticosteroids may be beneficial in the chronic fibroproliferative state of the disease. In a retrospective study we analysed the data of 31 non-trauma ARDS patients who had been on mechanical ventilation for at least 7 days. Thirteen cases received corticosteroids at a dosage equivalent to 100-250 mg methylprednisolone at the discretion of the attending physician in charge. Apart from corticosteroid administration, supportive care was identical in the treated and non-treated patient subgroups. Both groups were comparable regarding the relevant demographic, clinical and physiologic data, Apache-II score, radiological score, lung injury score and multiple organ failure score. Mortality in the treatment group was 38% (5/13) as opposed to 67% (12/18) in the untreated group (p = 0.117). There was a significant improvement in the PaO2/FIO2 ratio from a median of -26 to +5 mm Hg measured in a 48-hour period before and after corticosteroid treatment (p = 0.039). The response to corticosteroid therapy could not be predicted on the basis of clinical or physiologic data. Five patients responded within 48 h, and 3 showed a delayed response after 5-6 days. There were no significant complications attributable to corticosteroid treatment. CONCLUSIONS: Although the data of this first comparative study were retrospective, they suggest a beneficial effect of corticosteroid treatment in patients with established fibroproliferative ARDS. A prospective clinical trial, however, is highly warranted in order to fully elucidate the true effect of this therapeutic approach under controlled conditions.

APACHE↗
PubMed1997

Coronary flow and coronary flow reserve measurements in humans with breath-held magnetic resonance phase contrast velocity mapping.

Objective evidence for coronary lesion significance can be obtained with ischemic stress testing. Since flow-limiting stenoses have already undergone compensatory vasodilatation to maintain flow, the response to vasoactive stimulation is dampened. The degree of response limitation is reflected by the coronary flow reserve (CFR). Absolute volume flow rates can be accurately and noninvasively measured with MRI techniques. The purpose was to assess the ability to measure coronary volume flow rate noninvasively, and characterize the effect of pharmacologic stress on coronary flow quantitatively by using ultrafast, breath-held segmented k-space phase-contrast-MR imaging (PC-MRI). Ten healthy volunteers were examined by using ultrafast breath-held PC-MRI. Coronary volume flow rates were measured in the anterior descending coronary artery (LAD) at rest and following intravenous administration of dipyridamole. CFR was determined based on these data. Mean LAD volume flow rates increased from 38 +/- 11 ml/min before application of dipyridamole to 169 +/- 42 ml/min. The mean CFR amounted to 5.0 +/- 2.6 (median = 4.15). This study demonstrates the feasibility of breath-held PC-MRI to noninvasively quantify coronary volume flow rates over the cardiac cycle. Pharmacologically induced changes in volume flow rate and thus CFR can be quantitated.

Adult↗
PubMed1997

[Traumatic finger polyarthrosis in judo athletes: a follow-up study].

Osteoarthritis is the most common joint disease. In addition to known risk factors e.g. genetics, age and hormonal status it has been suggested that chronic-repetitive micro- and substantial (macro-) injury may play an important pathogenetic role. In a longitudinal case-study we examined Judo-players for clinical and radiological changes of the finger joints over the course of 16 years. All examined 8 players demonstrated soft tissue changes including Heberden nodes and radiological changes typical for osteoarthritis of the finger joints. Changes were symmetrical and were not restricted to joints with tendon ruptures or fractures in the anamnesis. Degenerative changes were progressive and more pronounced in active players. Subjectively, symptoms were usually mild. Extensive Judo seems to be a risk factor for the development of osteoarthritis of the finger joints due to chronic-repetitive micro- and substantial (macro-) injury.

Adult↗
PubMed1997

New approach to patency and flow assessment after left internal thoracic artery hypoperfusion syndrome with additional saphenous vein graft to the left anterior descending artery with phase-contrast magnetic resonance angiography.

OBJECTIVE: Perioperative and early postoperative flow reduction of a left internal thoracic artery conduit is a rare complication of myocardial revascularization and may lead to the potentially fatal left internal thoracic artery hypoperfusion syndrome. It has been advocated that an additional vein graft be placed to the distal left anterior descending artery to provide sufficient myocardial perfusion. Some evidence exists, however, that this high-flow vein might lead to competing or even backward flow through the internal thoracic artery. METHODS: In the past 2 years, 21 patients received an additional vein graft to the distal left anterior descending artery for left internal thoracic artery hypoperfusion syndrome. Nineteen of these patients were available for magnetic resonance imaging. Early (< 6 months) and late (> 12 months) postoperative flow measurements, both in the left internal thoracic artery and in the saphenous vein grafts, were performed by means of conventional and a segmented k-space phase-contrast magnetic resonance angiography technique. RESULTS: Early magnetic resonance examinations indicated that all conduits had adapted to the coronary flow type with predominant diastolic perfusion. Patency rate both at the early and at the late study was 100%. No concurrent flow, flow reversal, or steal phenomena were observed. Mean flow rates were 49.2 ml/min for the left internal thoracic artery and 72.6 ml/min for the saphenous vein graft. CONCLUSION: On the basis of the flow data obtained with magnetic resonance angiography, the use of an additional saphenous vein graft as the treatment of choice in left internal thoracic artery hypoperfusion syndrome does not lead to occlusion of the artery. Conduit flow adaptation to the diastolic predominance occurs in the first 6 months after operation.

Coronary Vessels↗
PubMed1997

[Bladder and rectal infiltration by uterine carcinomas: the accuracy of CT and MRI compared to endoscopic procedures].

PURPOSE: To establish the value of computed tomography (CT) and magnetic resonance imaging (MRI) in predicting bladder and rectum involvement in uterine carcinoma. MATERIAL AND METHODS: 6 different imaging signs (focal obliteration of perivesical or perirectal fat planes, area and angle of contact between uterus and bladder or rectum, asymmetric bladder or rectum wall thickening, evidence of intraluminal masses, and signal intensity of bladder or rectum wall on T2-weighted or contrast-enhanced MR images) were analysed retrospectively in 129 patients who underwent 92 CT and/or 64 MRI examinations. The data were correlated with intraoperative findings and the results of cystoscopy and rectoscopy. RESULTS: Asymmetric wall thickening, evidence of intraluminal masses and increased signal intensities of the bladder wall or rectum wall were valuable signs of infiltration (sensitivity 71-100%, specificity 91-96% and accuracy 89-97%). In 27 patients submitted to both imaging examinations MRI was somewhat superior compared to CT (p > 0.1) and yielded similar results as endoscopic procedures (accuracy of cystoscopy and rectoscopy of 90% and 94%, respectively). CONCLUSION: CT and MRI allow to predict involvement of bladder or rectum wall in carcinoma of the uterus with a similar accuracy as endoscopic procedures.

Aged↗