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Biomedical subjects

P Weber

Publications and source records attributed to P Weber.

At least 163 records · Page 9Linked to original sources
PubMed1994

Successful monochemotherapy of extensive gastrointestinal Kaposi's sarcoma with bowel obstruction in acquired immunodeficiency syndrome.

We report the case history of a 28-year-old homosexual man of Caucasian origin whose diagnosis of acquired immunodeficiency syndrome was established one year before admission on the basis of a positive human immunodeficiency virus serology and cutaneous Kaposi's sarcoma. Severe postprandial vomiting pointed to bowel obstruction in an emaciated, poor risk patient. Endoscopy revealed multifocal, violaceous tumours throughout the upper gastrointestinal tract which, eventually, obstructed the duodenum. Histology confirmed the putative diagnosis of gastrointestinal Kaposi's sarcoma, which responded well to monochemotherapy with vincristine. Significant clinical improvement and repeat endoscopy indicated tumour regression and resolution of bowel obstruction.

Adult↗
PubMed1994

[Rapidly growing tumor of the hand--is tuberculosis as differential diagnosis gaining increased importance?].

A two-year-old healthy, Portuguese girl presented with a prominent, painless tumor over the first web space of the left hand. The tumor increased rapidly in size over a few weeks, but caused no functional problems. On X-ray films, a cystic structure of the first metacarpal bone with erosion of the corticalis was demonstrated. At operation, a "cold abscess" was found. Bacterial examination of the gastric juice showed acid-resistant bacilli. The spina ventosa (Latin: Spina-"a thorn"; ventosa-"full of wind, distended") is a typical extrapulmonary manifestation of tuberculosis in phalangeal, metacarpal, and metatarsal bones of children. The recognition of this diagnosis is very important and will become more so in the future as it has already been seen in HIV-positive children in the USA, as well as in immuno-suppressed children and in un-vaccinated and malnourished children from war zones in eastern Europe.

Bone Regeneration↗
PubMed1994

[Liver transplantation in halothane-induced liver necrosis].

The risk for developing acute liver failure after halothane exposition was calculated between 1:8,000 and 1:36,000. The case report given on a 22 year old man with halothane-induced hepatic failure is unusual, because the typical risk factors as age over 40, female sex, obesity, and previous exposure to halothane were not present. Two days after exposure to halothane the patient suffered acute liver failure with severe coagulopathy (factor V = 5% activity), and encephalopathy grade IV complicated by renal failure and respiratory insufficiency. Maximal increases of enzymes in blood were AST 3900 U/L, ALT 2570 U/L, LDH 10600 U/L. After six days the patient underwent liver transplantation with complete anuria and instable circulation. Explanted liver showed massive necrosis (70% of parenchyma) and fatty changes. The liver transplant had immediately a good function and renal failure resolved within three days. In the follow-up of 3 1/2 years the patient suffered no further complications. Culturing the patient's lymphocytes in the lymphocyte transformation test a strong reaction could be detected with a stimulatory index of 20. Maximal proliferation was observed when lymphocytes were incubated with plasma metabolites of a volunteer drawn 120 minutes after anesthesia with halothane was started.

Adult↗
PubMed1994

Incidental finding of a hepatic lesion: differential diagnostic problems for fibrolamellar hepatic carcinoma.

We report the case of a 39-yr-old female with a liver lesion that was incidentally detected by ultrasound. Examination of biopsy specimens revealed focal nodular hyperplasia. A metastatic tumor in the right os ilium developed in the following weeks and showed specific uptake of 99mTc-hepatic 2,6-dimethyliminodiacetic acid (HIDA), suggesting metastasis from a differentiated hepatocellular carcinoma. The final pathologic diagnosis was multifocal, solid and glandular hepatocellular carcinoma, partly differentiated as fibrolamellar carcinoma, and an osseous metastasis from the differentiated hepatocellular carcinoma.

Adult↗
PubMed1994

Neutralizing antibody responses to autologous and heterologous isolates of human immunodeficiency virus.

Although laboratory-adapted strains of human immunodeficiency virus (HIV) are generally highly sensitive to neutralization by HIV-positive patient sera, we have found a more complex pattern of cross-neutralization and neutralization resistance among low-passage clinical isolates. These HIV isolates, like many other lentiviruses, resisted neutralization by the patient's own (autologous) antibodies. We assessed the degree of antigenic relatedness between different patient isolates of HIV through cross-neutralization with heterologous sera and virus isolates. Complicated patterns emerged, with variation in breadth of neutralization among individual plasmas and variation in frequency of neutralization among isolates. In longitudinal studies of individuals, we found that some but not all such patients develop a neutralizing response that "catches up" with their earlier isolates after a lag period. Taken together, these data suggest that an individual's immune response broadens with time because of cumulative exposure to multiple antigenic variants that arise throughout HIV disease.

Cells, Cultured↗
PubMed1993

The phenomenon of a high triglyceride response to an oral lipid load in healthy subjects and its link to the metabolic syndrome.

Excessive postprandial triglyceride (TG) responses despite normal fasting TG levels have been described in single cases within small groups of healthy subjects and in patients with obesity or precocious atherosclerosis, known to be associated with high insulin fasting levels. To clarify this association, fasting and postprandial TG and insulin levels were studied in 113 healthy young (25.7 +/- 2.6 years), normal weight (body mass index 20.8 +/- 2.3 kg/m2) male subjects who were selected from among 117 subjects on the basis of TG fasting levels < 200 mg/dl. After a 12-hour fast a standardized liquid lipid load was administered containing 58 g mainly saturated fat and 1,017 kcal energy. Both fasting TG values and postprandial TG peak values showed bimodal frequency distributions. Statistical analysis of fasting TG discriminated two groups: a low fasting TG group with normally distributed values < 150 mg/dl (mean +/- SEM: 79.5 +/- 2.7 mg/dl; n = 104) and a high fasting TG group > 150 mg/dl (194.5 +/- 7.2 mg/dl; n = 13). Likewise, two groups could be differentiated according to their maximal postprandial TG response (TG max) to the lipid load: (1) normal responders with TG max < 260 mg/dl (mean +/- SEM: 123 +/- 4.8 mg/dl; n = 96) and (2) high responders with TG max > 260 mg/dl (272.5 +/- 20.5 mg/dl; n = 17). Fasting TG and TG max were highly correlated (r = 0.745; p < 0.0001). However, 9 of 17 (53%) high responders had fasting TG < 150 mg/dl, which means that the prediction of high response is only 47.0% based on fasting TG values. Fasting insulin levels were significantly higher in high responders than in normal responders, whereas they did not differ between the low and high fasting TG group. In conclusion, the bimodal frequency distribution of TG max after a lipid load permitted the differentiation of two groups, normal responders and high responders, with higher fasting insulin levels, which might indicate a link to the metabolic syndrome.

Adult↗
PubMed1993

Subunit interactions provide a significant contribution to the stability of the dimeric four-alpha-helical-bundle protein ROP.

Detailed thermodynamic and spectroscopic studies were carried out on the ColE1-ROP protein in order to establish a quantitative basis for the contribution of noncovalent interactions to the stability of four-helix-bundle proteins. The energetics of both heat- and GdnHCl-induced denaturation were measured by differential scanning microcalorimetry (DSC) and/or by following the change in circular dichroism in the far-UV range. Sedimentation equilibrium analyses were performed to characterize the state of aggregation of the protein. No intermediate species could be detected during thermal unfolding of the dimer in the absence of GdnHCl. Under these conditions ROP unfolding exhibits a strict two-state behavior. The thermodynamic parameters for the reaction N2<->2D are delta HD = 580 +/- 20 kJ.(mol of dimer)-1, delta Cp = 10.3 +/- 1.3 kJ.(mol of dimer)-1.K-1, and Tm = 71.0 +/- 0.5 degrees C. The corresponding Gibbs energy change of unfolding is delta GD degree = 71.7 kJ.(mol of dimer)-1 at 25 degrees C and pH 6. In the presence of 2.5 M GdnHCl, however, ROP dissociates into monomers at elevated temperatures, as the loss of the concentration dependence of Tm and the decreased molecular weight demonstrate. The corresponding transition parameters are delta HD (2.5 M GdnHCl) = 130 +/- 10 kJ.(mol of monomer)-1 and Tm = 51.6 +/- 0.3 degrees C. Isothermal unfolding studies at 19 degrees C using GdnHCl as denaturant yielded a Gibbs energy change of unfolding of 22.4 kJ.(mol of monomer)-1. This extrapolated value is 38% lower than the corresponding delta GD degree value of 35.85 kJ.(mol of monomer)-1 calculated from thermal unfolding for the monomer in the absence of GdnHCl, where the protein is known to be a dimer. These results suggest that subunit interactions are an important source of stabilization of the native four-helix-bundle structure of ROP.

Bacterial Proteins↗
PubMed1993

Is penicillin G an adequate initial treatment for aspiration pneumonia? A prospective evaluation using a protected specimen brush and quantitative cultures.

OBJECTIVE: To evaluate the bacteriology of early aspiration pneumonia using a protected specimen brush and quantitative culture techniques, and whether penicillin G is adequate as initial treatment pending culture results. PATIENTS AND METHODS: 52 patients (of which 45 required mechanical ventilation) meeting usual clinical criteria for aspiration pneumonia were prospectively included. On admission, patients were given intravenous penicillin G and a protected specimen brush was performed < or = 48 h after. RESULTS: Cultures of the brush were negative (< 10(3) CFU/ml) in 33 patients (1 had blood cultures positive with S. pneumoniae) and positive (> or = 10(3) CFU/ml) for S. pneumoniae in 2 patients. Seventeen patients had a positive culture (> or = 10(3) CFU/ml) for at least one penicillin G resistant microorganism, with a total of 20 organisms (S. aureus: 6; H. influenzae: 2; Enterobacteriaceae: 8; P. aeruginosa: 3; C. albicans: 1). In 4 of these patients, a penicillin-sensitive pathogen was also recovered in significant concentrations (S. pneumoniae: 2; Streptococcus sp.: 2). These 17 patients with a resistant pathogen did not differ from the 35 other patients with respect to need for ventilatory support and mortality rate. By contrast, they were older (61.1 +/- 21.9 vs. 42.9 +/- 18.8 years; p < 0.005) and required longer mechanical ventilation (6.1 +/- 4.6 vs. 3.5 +/- 2.7 days; p < 0.03) and hospitalization (11.2 +/- 8.8 vs. 6.7 +/- 4.7 days; p < 0.02). Of 17 patients 12 with penicillin G resistant organisms versus 0/35 without, were in-hospital patients and/or had a digestive disorder (p < 0.001). CONCLUSION: The broad range of offending organisms seen in early aspiration pneumonia precludes use of any single empiric regimen, making protected specimen brush mandatory in many patients. Nevertheless, the involvement of S.pneumoniae in a notable proportion of our patients suggests that routine penicillin prophylaxis after early aspiration (at least in most patients with community-acquired aspiration) is warranted given the potential severity of pneumococcal sepsis in such patients.

Adult↗
PubMed1993

Protective activity of a murine monoclonal antibody against European bat lyssavirus 1 (EBL1) infection in mice.

A mouse model was designed to test in vivo the efficacy of rabies immune globulins and specific neutralizing monoclonal antibodies to prevent European bat lyssavirus 1 infection. Human or equine rabies immune globulins previously found to contain variable amounts of neutralizing bat lyssavirus crossreactive antibodies were passively transferred to mice receiving intramuscularly a lethal dose of bat lyssavirus type 1. Immune globulins did not protect mice well against bat lyssavirus 1 whereas they reduced the mortality caused by rabies virus. In contrast, mice inoculated with bat lyssavirus 1 or rabies virus survived when passively immunized with bat lyssavirus 1 specific monoclonal antibody (mAb 8-2). This monoclonal antibody, an IgG2 alpha, recognized an epitope located in the antigenic site IIa of rabies glycoprotein. A mutation replacing the lysine 198 by glutamate in a rabies variant abrogated sensitivity to this neutralizing antibody. Because of its broad neutralizing spectrum against wild virus isolates, including European bat lyssaviruses, this monoclonal antibody should be a good candidate for rabies immune globulin replacement. It could improve efficacy of rabies vaccination, used either alone or in conjunction with human rabies immune globulins or monoclonal antibody cocktail to supplement their lack of crossreactivity to European bat lyssavirus 1.

Animals↗
PubMed1993

Acute pancreatitis in Crohn's disease.

Pancreatitis as an extraintestinal manifestation of Crohn's disease (CD) is controversial. We review the episodes of acute pancreatitis in patients with CD. Of 852 patients, 12 developed clinically overt pancreatitis, representing a frequency of 1.4% in a follow-up period of 10 years. In 10 patients, common causes of pancreatitis were excluded. In 2 patients, drug-induced disease (azathioprine, sulfasalazine) could not be ruled out. Recurrence of pancreatitis was observed in only 2 patients. Younger patients and those with active disease seemed more at risk for development of pancreatitis. If prednisolone was needed for treatment of active CD, no adverse effect was observed for the pancreatitis. Along with the clinical features, we studied autoantibodies against exocrine pancreas; the incidence of autoantibodies in patients with pancreatitis was the same as in the controls who did not develop pancreatic abnormalities. This does not support the hypothesis that acute pancreatitis in CD is associated with the formation of pancreatic autoantibodies.

Acute Disease↗
PubMed1993

[Ogilvie's syndrome after cesarean section. Apropos of 3 cases. Review of the literature].

Ogilvie's syndrome or pseudo-obstruction of the colon shows up as a clinical picture of acute obstruction of the large bowel without an associated pathological lesion as usually occurs in older patients. Three cases of Ogilvie's syndrome following Caesarean section are reported in this work. Caesarean section seems to be the most common operative procedure associated with this syndrome. Up till now 41 cases have been described in the literature. This syndrome is serious because it is possible for the caecum to burst causing faecal peritonitis which carries a heavy mortality. Seventeen cases of perforation of the caecum have been reported in the literature. The diagnosis is made by x-raying the patient's abdomen without any pre-x-ray preparation; if an enema of gastroffin is given it can be shown that there is no organic cause for the obstruction. The pathological cause seems to be disturbance of the autonomic innervation of the colon. The colon should be decompressed rapidly; and the present technique is to do this using a colonoscope with or without epidural anaesthesia. Surgery should be reserved for cases that have complications or that have been refractory to conservative treatment. Of our three cases two were treated successfully by colonoscopic decompression and one with the use of drugs.

Adult↗
PubMed1993

[Teratogenicity of retinoids. A case and review of the literature].

Retinoids are vitamin A derivatives used in dermatology. One of them, isotretinoin, is frequently prescribed for refractory juvenile acne. The teratogenetic power of this drug is substantial, being estimated at 15 to 45% of exposures in utero. The risk is maximum in the first trimester of pregnancy and persists up to one month after treatment has been discontinued. The most frequently described multiple malformation syndrome involves the face, the central nervous system and the heart. There is also a 20 to 30% rate of spontaneous abortion. The authors report a case where exposure during the first trimester did not result in foetal malformation. From a full review of the literature the various malformations observed, the presumed mechanisms of teratogenesis and the strict rules of prescription and surveillance in women child-bearing age are presented. The problem of the measures to be taken in case of retinoid treatment during pregnancy is discussed. The teratogenic risk from other retinoids is dealt with.

Adult↗
PubMed1993

[Algorithm for calibrating eye movements].

A mathematical model and the corresponding computer program based on an algorithm for calibration of eye movements are described. The latter is used to represent and analyse eye movements on a monitor screen using the EYE/HAND software, with the aid of which movements of eye and hand can be represented either simultaneously or separately. Demands on the rate of data acquisition and representation of the curves (real-time monitoring) are satisfied. Calibration is based on vector transformation of the digitised analog values to monitor coordinates. The parameters of the transformation algorithm are determined by fixation of the eye movements to freely selectable monitor screen markers.

Calibration↗
PubMed1993

[Benckiser's hemorrhage. 2 case reports and a review of the literature].

Benckiser's haemorrhage is a pure foetal bleeding due to rupture of one or several umbilical vessels located within the presentation area and usually associated with velamentous insertion of the cord. The frequency of this accident has been estimated at 1:2000 to 1:5000 deliveries. The clinical picture consists of haemorrhage occurring during rupture of the membranes and rapid foetal suffering responsible for foetal death from acute exsanguination in 75 to 100% of the cases. The maternal prognosis is excellent. Since the first clinical description, in 1801, less than 200 cases have been published. Many atypical forms delaying the diagnosis have been noted. The authors report 2 lethal cases with misleading clinical presentations. With intact membranes, prevention rests on the diagnosis of vasa praevia made by vaginal palpation, amnioscopy or even ultrasonography combined with colour-coded doppler velocimetry. With ruptured membranes, the diagnosis is usually retrospective and bases on examination of the secundines. Testing foetal haemoglobin in the vaginal blood can be very useful in the absence of acute foetal suffering. The management of this haemorrhage is discussed.

Adult↗