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Biomedical subjects

A Zimmermann

Publications and source records attributed to A Zimmermann.

At least 19 recordsLinked to original sources
PubMed1992

[Glomerulonephritis with transient C3 hypoclompimentemia and endotheliomesangial glomerulonephritis in childhood. A long-term experience].

62 children (20 girls and 42 boys, ranging in age between 3 and 15 years), presenting with acute hypocomplementemic glomerulonephritis or morphologically confirmed endotheliomesangial glomerulonephritis, were admitted to the University Children's Hospital, Berne from 1970 to 1991. The annual incidence of cases of acute hypocomplementemic glomerulonephritis was stable during the study period. The site of the antecedent infection was the throat in 26 patients, upper respiratory tract in 15, the skin in 9, and unknown in 10. The latent period ranged from 0.5 to 3.5 weeks. 41 patients developed hypertension and 17 renal failure. Hypertensive complications were observed in 6 patients and remitted completely in 5 cases. A nephrotic syndrome (edema, proteinuria of 40 mg/[m2.h], albuminemia < 25 g/l) was observed in 11 patients. Microscopic hematuria persisted in many patients for one year or more. Proteinuria remitted in all but one patient, who was found to have Alport syndrome. This study shows the stable frequency of hypocomplementemic glomerulonephritis since 1970, its good prognosis, and the importance of the measurement of C3-complementemia in children presenting with acute glomerulonephritis.

Adolescent↗
PubMed1992

[Toxicity of an organic Germanium compound: deleterious consequences of a "natural remedy"].

Reports mainly from Japan, recommend germanium (Ge)-containing compounds as "anti-cancer" and "immunostimulatory" remedies. We report on a 25-tear-old woman with stage II HIV disease who consumed a total of 47 g Ge as Ge-lactate-citrate 18%. She developed severe renal insufficiency (creatinine clearance 7 ml/min/1.73 m2, proteinuria 0.28 g/d) and hepatomegaly. Biopsies revealed tubulointerstitial nephropathy with vacuolar degeneration, mainly of distal tubular epithelia, and severe liver steatosis. Tissue Ge content in kidney and liver biopsy specimens was increased 68-and 140 fold respectively. In agreement with previous reports, renal dysfunction persisted 9 months later (creatinine clearance 11 ml/min/1.73 m2).

Acute Kidney Injury↗
PubMed1992

Carcinosarcoma of the urinary bladder: a distinct variant characterized by small cell undifferentiated carcinoma with neuroendocrine features.

The clinicopathological features of two carcinosarcomas of the urinary bladder are reported. The tumours occurred in a 64- and a 66-year-old patient presenting with haematuria and both were polypoid. The epithelial component was consistent with small cell undifferentiated carcinoma with neuroendocrine differentiation, whereas the sarcomatous component did not display specific features. The carcinomatous component showed immunohistochemical reactivity for different epithelial markers as well as for chromogranin and neuron specific enolase. Conversely, the sarcomatous cells stained strongly for vimentin and in one case for muscle actin and smooth muscle actin. The differential diagnosis of biphasic tumours of the bladder is discussed and the literature reviewed.

Actins↗
PubMed1992

Reversibility of secondary biliary fibrosis by biliodigestive anastomosis in the rat.

Biliary cirrhosis with portal hypertension and hepatocellular failure is a well-known complication of extrahepatic obstruction. It is unclear to what extent these changes are reversible by biliodigestive anastomosis. Therefore a rat model of relief of biliary obstruction was developed by performing Roux-en-Y choledochojejunostomy in rats after bile duct obstruction. Patency of the biliodigestive anastomosis was documented by biliary scintigraphy. Microsomal function was assessed in vivo by the aminopyrine breath test and portal hypertension by spleen pulp pressure. Microsomal function was markedly impaired in obstructed animals but recovered after biliodigestive anastomosis. Microsomal cytochrome P450 content paralleled these changes. Similarly, portal hypertension was reversed after successful relief of obstruction. Stereologic analysis showed that biliodigestive anastomosis partially reversed bile ductular proliferation and fibrosis. Studying the time course of recovery showed that restoration of microsomal function was achieved after 2 weeks whereas recovery from portal hypertension required 4 weeks of biliary drainage. Recovery of microsomal function was paralleled by normalization of microsomal lipid composition while resolution of portal hypertension occurred parallel to resolution of the histologic abnormalities.

Anastomosis, Roux-en-Y↗
PubMed1992

Cystadenoma of the seminal vesicle: case report and literature review.

A benign fibroepithelial and cystic tumor of the seminal vesicle is described in a 63-year-old man. The symptoms, macroscopic appearance, microscopic characteristics, immunophenotype prognosis and complications of this rare benign tumor are discussed, and 9 previously reported cases are reviewed. Several terms have been used to describe benign fibroepithelial tumors of the seminal vesicle. We suggest that the term cystadenoma is the most appropriate.

Cystadenoma↗
PubMed1992

Effects of staurosporine, K 252a and other structurally related protein kinase inhibitors on shape and locomotion of Walker carcinosarcoma cells.

The structure/activity relationship of the protein kinase inhibitors, staurosporine and K 252a and their analogues on motility of Walker carcinosarcoma cells has been studied in vitro. Staurosporine and K 252a, similar to phorbol myristate acetate (PMA) and diacylglycerols, suppress cell polarity and locomotor activity of Walker carcinosarcoma cells. Staurosporine inhibits spontaneous and colchicine-induced front-tail polarity (ID50 of about 6.0 x 10(-8) M) as well as spontaneous and colchicine-stimulated locomotion at 10(-7) M. K 252a suppresses cell polarity (ID50 of about 4.5 x 10(-6) M) and inhibits spontaneous and colchicine-stimulated locomotion at 10(-5) M, but suppression of locomotor activity is not complete in the presence of colchicine. CGP 41251, a staurosporine derivative with a much higher specificity for protein kinase C (PKC) than staurosporine, induces a dose-dependent increase in the proportion of polarised cells, and stimulates cell locomotion. Two K252a analogues, KT 5720 and KT 5822, which act preferentially on cyclic nucleotide-dependent protein kinases, and CGP 42700, an inactive staurosporine analogue, had no effect on cell polarity and locomotion. The findings suggest that protein kinase inhibitors acting preferentially on PKC may be of interest in pharmacological regulation of tumour cell locomotion.

Alkaloids↗
PubMed1992

Urodilatin, not nitroprusside, combined with dopamine reverses ischemic acute renal failure.

The present study was undertaken to: (a) clarify the comparative renal potency of bolus injection of the natriuretic peptides urodilatin and ANF99-126 in the rat; (b) establish whether or not intravenous (i.v.) infusion of urodilatin (200 ng/min) combined with dopamine (UD) to maintain mean arterial pressure could improve GFR or renal histology in established experimental ischemic acute renal failure (ARF) induced by 30 minutes of bilateral renal artery clamping; (c) assess comparative efficacies of nitroprusside, an activator of soluble guanylate cyclase, combined with dopamine (ND) or control infusions of dopamine alone (DA), under equivalent conditions; and (d) determine effects of intra-renal arterial infusions of the stable cGMP analogue dibutyryl-cGMP immediately after renal artery clamping (RAC). After initial dose finding studies, i.v. infusion of UD 24 hours after 30 minutes of RAC improved GFR over five hours from 0.24 +/- 0.04 to 1.0 +/- 0.16 ml/min in association with a threefold rise in plasma cGMP and a 13-fold increase in urinary cGMP excretion. Plasma creatinine dropped by 41% from 230 +/- 16 to 135 +/- 18 microM/liter and was still reduced 24 hours later with values averaging 106 +/- 14 compared to 274 +/- 53 microM/liter in non-treated animals. During infusion, UV and FENa+ increased from 1.4 +/- 0.2 to 8.3 ml/min, and from 2.9 +/- 0.5 to maximum values of 15.8 +/- 2.4%. ND or DA alone were less effective, increasing GFR only to 14 and 20%, respectively, of normal values, but improvements were not sustained; in contrast to UD, ND did not alter plasma or urinary cGMP. In addition, DBcGMP was ineffective in improving GFR during early ARF. Histologically UD, but not ND, markedly reduced the incidence of granular casts, tubular desquamation and tubular necrosis in cortical areas and increased the incidence of medullary mitoses.

Acute Kidney Injury↗
PubMed1992

Enucleation of giant hemangiomas of the liver. Technical and pathologic aspects of a neglected procedure.

Cavernous hemangiomas are the most common benign tumors of the liver. Giant cavernous hemangiomas, defined as those larger than 4 cm in diameter, can reach enormous proportions. Newer imaging modalities, although often demonstrating characteristic features that strongly suggest the diagnosis, should not be augmented by biopsy because of the risk of hemorrhage. Elective surgical resection may be indicated for symptomatic giant lesions and for those with an atypical appearance where the diagnosis is in doubt. Between October 1986 and May 1991, we treated 10 patients with giant hemangiomas by enucleation or enucleation plus resection. Median operative blood loss was 800 mL (range, 200 to 3000 mL). One patient required reoperation for control of postoperative hemorrhage. Detailed pathologic examination has demonstrated an interface between hemangiomas and the normal liver tissue that allows enucleation. Enucleation is an underused procedure that if carefully performed allows resection of giant hemangiomas with a reduced blood loss and the preservation of virtually all normal hepatic parenchyma.

Adult↗
PubMed1992

Hyperoxia-induced airway remodeling in immature rats. Correlation with airway responsiveness.

We recently found that exposure of 21-day-old rats to hyperoxia (> 95% O2 for 8 days) significantly increased in vivo airway cholinergic responsiveness and that O2 exposure also increased airway epithelial and smooth muscle layer thicknesses in a separate cohort of animals. There was substantial variation in the magnitude of both the functional and structural responses to hyperoxia. The present study was designed to test whether the magnitude of O2-induced airway remodeling could account for individual differences in airway responsiveness after O2 exposure, as well as for the difference in responsiveness between air- and O2-exposed animals. We assessed in vivo airway responsiveness to aerosolized acetylcholine (ACh) and airway architecture in 14 O2- and 5 air-exposed, immature rats. Total respiratory system resistance was determined using a plethysmographic method. The mean thicknesses and fractional areas of the airway epithelial and smooth muscle layers were determined by contour tracing using a digitizing pad and microcomputer. Both the small (circumference < 1,000 microns) and central (circumference 1,000 to 4,000 microns) airways were studied. For O2-exposed rats, individual values of EC200 ACh correlated negatively with small airway smooth muscle layer thickness (r = -0.59, p < 0.05; ANOVA), small airway smooth muscle layer fractional area (r = -0.75, p < 0.01), small airway epithelial thickness (r = -0.54, p < 0.05), small airway epithelial fractional area (r = -0.69, p < 0.01), and central airway smooth muscle layer thickness (r = -0.53, p < 0.05). When both air- and O2-exposed animals were considered, EC200 ACh correlated negatively with all eight parameters of airway layer thickness and fractional area.(ABSTRACT TRUNCATED AT 250 WORDS)

Acetylcholine↗
PubMed1992

Clonal analysis of human tumors with M27 beta, a highly informative polymorphic X chromosomal probe.

The clonality of human tumors can be studied by X inactivation/methylation analysis in female patients heterozygous for X-linked DNA polymorphisms. We present a detailed study on clonal tumor analysis with M27 beta, a highly informative probe detecting a polymorphic X chromosomal locus, DXS255. The polymorphism detected at this locus is due to variable numbers of tandem repeats. The rate of constitutional heterozygosity detected by M27 beta was 88%. Normal tissue from gastrointestinal mucosa and thyroid showed random, hence polyclonal, patterns. Nonrandom clonal X inactivation was detected in all 22 malignant neoplasms that had been shown to be clonal by other DNA markers, such as antigen receptor gene rearrangements or clonal loss of heterozygosity at 17p and other loci. 16/48 normal blood leukocyte samples (33%) showed considerably skewed X inactivation patterns. Comparison of blood leukocytes and normal tissue indicated that in a given individual, X inactivation patterns may be tissue specific. M27 beta was used to study the clonal composition of 13 benign thyroid nodules from 12 multinodular goiters with rapid recent growth, traditionally termed "adenomas." Nine of them were clonal, whereas four nodules and tissue from a case of Graves' goiter were not, indicating that some, but not all, such thyroid nodules may represent true clonal neoplasms. The M27 beta probe permits one to study the clonal composition by the X inactivation approach of a wide variety of solid tumors from most female patients. As a control, normal tissue homologous to the tumor type of interest is preferable to DNA from blood leukocytes, since the latter may show nonrandom X inactivation patterns in a fairly high proportion of cases. M27 beta may, therefore, be of limited use for the clonal analysis of neoplasms derived from hematopoietic cells.

Clone Cells↗
PubMed1992

[The synthesis of collagenous and noncollagenous proteins by cells from the periodontium].

Synthesis of collagenous and noncollagenous proteins by cells originating from the alveolar bone (AB-cells) and from the periodontal ligament (PDL-cells) of 8 minipigs was analyzed in primary cell cultures. Incorporation of 3H-proline into proteins recovered from cell extracts showed, that 13.7% of protein synthesized by AB-cells and 8.0% of protein synthesized by PDL-cells were collagens. In both cell lines relative amounts of collagens synthesized decreased significantly on subculturing (AB-cells: 9.3%, PDL-cells: 6.0%). Preincubation of 2nd subculture AB-cells with beta-glycerophosphate had no significant effect on collagen synthesis. Considering the fact that relative amounts of collagen recovered from cell extracts represent only 10-20% of collagen recovered from whole culture (i.e. cells and culture medium), we suggest that collagen synthesis is an important component of in vitro-protein synthesis of cells originating from the alveolar bone and the periodontal ligament.

Alveolar Process↗
PubMed1992

[Experimental atrophy/hypertrophy complex of the liver after portal and/or biliary ligation in the rat].

Patients with lobar or segmental, benign or malignant strictures of the biliary tree (with or without impairment of the portal blood flow) show a considerable atrophy of the involved area of the liver with a compensatory hypertrophy/hyperplasia of the remaining non affected liver. To investigate the importance of the biliary and portal obstruction for the development of this process, we used a rat model, with selective biliary and/or portal ligation of the anterior liver lobes (two thirds of the liver mass). Weight measurements, morphometry, functional scintigraphy (Hepatoiodida-scan) and blood enzyme analyses were done immediately postoperatively, at 30 hours and 4, 8 and 28 days after the operation. The major findings were: 1. 28 days after biliary and/or portal ligation there was no difference between the body weight of the four groups, all ligated animals having compensated for an initial greater percentage body-weight loss. 2. Total liver weight remained constant, while atrophy and hypertrophy/hyperplasia occurred although a progressive derangement of liver morphology was observed during that time. 3. A severe atrophy-hypertrophy-complex (AHC) developed after selective portal ligation, which in our experiment did not appear after selective biliary ligation. 4. Morphometrical changes after selective biliary ligation were reversible, whereas in liver lobes with selective portal ligation a progressive parenchymal destruction and involution with subsequent impairment of hepatic function of the concerned lobe was observed.

Animals↗
PubMed1992

[Acute myocardial infarction: recent physiopathological data. 1: acute coronary occlusion].

Acute myocardial infarction is the result of sudden coronary occlusion in the absence of a collateral circulation. There main factors are required for this to occur: an acute parietal lesion on a stenosis of variable, sometimes minor, importance; local coronary vasoconstriction and a platelet and fibrin thrombus. Parietal fissuration is the commonest "trigger" of coronary spasm and the thrombotic cascade. All factors of coronary occlusion are potentially reversible--vasodilation--platelet anti-aggregation--physiological fibrinolysis--remodeling and cicatrisation of the plaque, thereby explaining cases of spontaneous regression of occlusion (10% at 1 hour; 20% at 6 hours; 30% at 24 hours; 50 to 70% at 1 year). The pathogenesis of myocardial infarction with angiographically normal coronary arteries may be reviewed and attributed to acute parietal fissuration at a non-significant or angiographically undetectable plaque resulting in occlusive thrombosis. In this case, the role of other pathogenic factors is also discussed (diabetes, oral contraception, haemostatic abnormalities, platelet disorders...).

Coronary Angiography↗
PubMed1992

[Urinary N-methylhistamine excretion. Following exogenous histamine administration and allergy/exercise-induced bronchoconstriction].

Histamine is partly metabolized to a stabile metabolite N-methyl-histamine and excreted in the urine. We analysed the degradation of infused histamine and the N-methyl-histamine-excretion in atopic and normal individuals as in patients with a bronchoconstriction due to allergen/exercise challenge. N-methyl-histamine was determined by a newly developed radioimmunoassay. 60 controls and 38 atopic individuals were investigated. There is a proportional increase of N-methyl-histamine in the urine in young children. However, no significant difference between allergic and non-allergic individuals was found. After parenteral administration of a standardized amount of histamine 12% of the applied amount was secreted in the urine as N-methylhistamine. The most significant increase of N-methylhistamine-excretion was observed in the first hour after application. Only an 0.1% rise of N-methyl-histamine was observed following an oral administration of histamine. Neither bronchial challenge with specific allergen nor physical exercise elicited significant changes of N-methylhistamine excretion. The secretion of N-methyl-histamine demonstrates the degradation of histamine in the circulation, the measurement oft this metabolite in the urine should be considered when analysing the cause of severe systemic allergic reaction as anaphylaxis but not asthma or atopic disposition.

Adolescent↗
PubMed1992

[Liver biopsy in suspected alcoholic liver damage].

Alcohol can induce a wide spectrum of histological changes in the liver. Three morphologic patterns of alcoholic liver injury are now generally accepted, i.e. fatty change, alcoholic hepatitis and alcoholic cirrhosis, but a broad array of lesions has been added to this list in recent years. These damage patterns differ considerably in their significance as to indication and diagnostic power of liver biopsies. Liver biopsy is recommended in patients with clinically suspected alcoholic liver disease for diagnostic and prognostic reasons. Moreover, clinicians want to exclude nonalcoholic liver diseases that might otherwise be missed. Alcoholic hepatitis, which is associated with increased morbidity and mortality, has the highest degree of diagnostic specificity in biopsies, because its features are well-defined and are mimicked by a rather small group of other causes. When associated with perivenular and pericellular fibrosis, it may provide prognostic parameters. In contrast, fatty liver, which may be induced by alcohol as well as other etiologies, usually does not need liver biopsy, with some exceptions. It may lead to cholestasis severe enough to mimic obstructive jaundice, or may result in abnormal imaging studies suggesting metastases. Verification of histological findings may be important when these circumstances arise. Cirrhosis is easily verified in biopsies of appropriate quality; however, advanced cirrhosis is a morphologically nonspecific alteration, because cirrhotic tissue patterns converge irrespective of their cause. Liver biopsy may help to identify nonalcoholic liver disease in patients suspected of harboring alcoholic liver disease. In fact, up to 20% of biopsies may show other, potentially treatable disorders, thus extending the indication for liver biopsy in situations of complex clinical and laboratory patterns.

Biopsy, Needle↗
PubMed1991

[Cyst of the seminal vesicle with ipsilateral kidney agenesis].

Unilateral cyst of the seminal vesicle, ipsilateral ectopic ureter and ipsilateral renal agenesis are the components of a rare congenital abnormality affecting the male urogenital tract. The clinical picture is characterized by a retrovesical cystic tumor which may be asymptomatic or cause nonspecific symptoms. Differential diagnosis includes cysts of the Müllerian duct, the urogenital sinus/ejaculatory duct, and the prostate. Pelvic ultrasonography is an appropriate method of investigating patients in whom this malformation is suspected, whereas more invasive radiologic procedures are indicated in selected cases only. Treatment for retrovesical cysts should be restricted to symptomatic patients. Conservative therapy may result in subjective improvement, but surgical exploration and excision of the abnormal organs is the only definitive treatment.

Abnormalities, Multiple↗