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Biomedical subjects

J Richter

Publications and source records attributed to J Richter.

At least 145 records · Page 8Linked to original sources
PubMed1998

[Thymectomy in myasthenia gravis--an analysis of current status].

Between May 1992 and June 1997, 11 patients with myasthenia gravis and 1 asymptomatic patient with thymoma underwent extensive thymectomy through a median sternotomy. Seven patients were male and 5 female. The mean age at onset of myasthenia gravis was 46.5 (13-73) years. The interval between the first symptom and diagnosis was 3.6 months (1 week-7 months), between the first symptom and thymectomy 8.3 months (2 weeks-36 months) and the mean follow-up period was 28.4 months (3-57 months). Clinical improvement after extensive thymectomy was noted in 80% of patients. Four patients became asymptomatic under decreased medication. Thymectomy was found to be beneficial even in older patients or patients with the purely ocular type of myasthenia gravis. There was no perioperative mortality or long-term morbidity.

Adolescent↗
PubMed1998

[Intramedullary boring in infected intramedullary nail osteosyntheses of the tibia and femur].

UNLABELLED: The infection after intramedullary nailing is a severe complication, which is hard to eradicate. The results of reaming the intramedullary canal after removal of the infected nail were evaluated in our investigation. From 1984 to 1991 fifty-five patients with infected intramedullary nails of the lower extremity were included in this trial. Twenty-one patients had an infection of the femur. Thirty-four patients had a primary infection of the nail, twenty-one patients had multiple operations with periods of infection prior to nailing. All patients had signs of a chronic osteitis and sinus formation. At the time of the follow-up the success of the procedure was evaluated regarding recurrence of infection, range of motion of the extremity and patient comfort. The mean time of observation was 10.1 +/- 4.9 years. All patients with initially infected intramedullary nails had no recurrence of the infection, compared to 62% of those with multiple operations prior to nailing. At the time of the follow up all fractures had healed. 85% of the patients performed full weight bearing. 32 patients (91%) had good or excellent ROM of the adjacent joints. CONCLUSION: Intramedullary reaming after infected nails is a successful procedure and results in infect healing in the majority of patients.

Adult↗
PubMed1998

Ultrastructural pathology of the alveolar type II pneumocytes of human donor lungs. Electron microscopy, stereology, and microanalysis.

Alveolar type II pneumocytes (PII) were studied in 12 human donor lungs perfused with modified Euro-Collins solution during single-lung transplantation (SLTx). While one lung was transplanted, the contralateral donor lung (cDL) was fixed at the time of SLTx for examination by electron microscopy, stereology, and microanalysis. Three groups were then formed: group A (n = 7), cDL without contusions, uneventful early postoperative course; group B (n = 3), cDL with conclusions, uneventful early postoperative course; group C (n = 2), cDL without contusions, early postoperative respiratory dysfunction. The major findings were that the presence of contusions had no effect on PII ultrastructure and that intracellular surfactant-storing lamellar bodies of cDL in group C were characterized by a higher volume-to-surface ratio (VsR) and larger area per cell profile than group A. Correlation analysis based on pooled data (groups A and C) showed that ischaemic time had little effect on PII ultrastructure and bore no relationship to postoperative clinical variables. The duration of preoperative donor intubation had a pronounced influence on ultrastructure and postoperative clinical variables. The stereologically estimated amount of intracellular surfactant and mitochondrial VsR were the only ultrastructural parameters that were significantly associated with early postoperative oxygenation. Lamellar bodies were the only ultrastructural components found to have a significant relationship to postoperative intubation time. The ultrastructural integrity of type II pneumocytes of human donor lungs is an important determinant of early respiratory function following clinical lung transplantation.

Adolescent↗
PubMed1998

Chromosomal imbalances in papillary renal cell carcinoma: genetic differences between histological subtypes.

Papillary renal-cell carcinoma (RCC) is a renal carcinoma variant with distinct gross, microscopic, and cytogenetic features. Recently, a type 1 (pale cytoplasm, small-cell) and a type 2 (eosinophilic cytoplasm, large-cell) subtype of papillary RCC have been described. Chromosomal alterations associated with these tumor types were examined in 25 papillary RCCs by comparative genomic hybridization. Relative copy number gains were frequently detected at chromosomes 7p (56%), 7q (44%), 12q (28%), 16q (32%), 17p (56%), 17q (76%), and 20q (32%). Chromosomal regions that were most often lost included 1p (24%), 4q (36%), 6q (40%), 9p (36%), 13q (36%), Xp (28%), Xq (36%), and Y (73%). There were clinical and genetic differences between the subtypes of papillary RCC. Type 2 tumors were of higher nuclear grade (P = 0.0012) and higher stage (P = 0.01) and had a worse prognosis (P = 0.03) than type 1 tumors. The number of DNA gains per tumor, especially gains of 7p and 17p, was significantly higher in type 1 than in type 2 tumors (P < 0.01). These data suggest the existence of two distinct morphological and genetic subgroups of papillary RCC. Losses of chromosome Xp were associated with short patient survival (P < 0.01). Despite the small number of cases, this finding suggests that a gene on chromosome Xp may contribute to papillary RCC progression.

Carcinoma, Papillary↗
PubMed1998

Patterns of chromosomal imbalances in advanced urinary bladder cancer detected by comparative genomic hybridization.

To identify genetic changes linked to bladder cancer progression we analyzed 90 invasive transitional cell carcinomas (37 pT1 and 53 pT2-4) by comparative genomic hybridization. The most frequent alterations included 1q+ (37%), 5p+ (24%), 6q- (19%), 8p-(29%), 8q+ (37%), 9p- (31%), 9q- (23%), 11p-(24%), 11q- (22%), 17q+ (29%), and 20q+ (28%). Interestingly, there were three groups of alterations that frequently occurred together (9p- and 11q13+/ 20q+ and 11q13+ or 17q+/1q+ and 3p+ or 11q-). These loci might carry genes that interact with each other in specific molecular pathways. There were remarkable genetic similarities between minimally and deeply invasive tumors of different histological grades, including a similar number of aberrations per tumor and an equal frequency of most individual alterations. However, deletions of 5q, 6q, and 15q and gains of 5p, 7p, and Xq were significantly more frequent in pT2-4 than in pT1 carcinomas. These loci may harbor genes that are important for bladder cancer progression.

Chromosome Aberrations↗
PubMed1998

Double-blind comparison of lansoprazole 15 mg, lansoprazole 30 mg, and placebo in the maintenance of healed gastric ulcer.

Our purpose was to compare the safety and efficacy of lansoprazole 15 mg and 30 mg with placebo in preventing recurrence in 49 patients with a history of gastric ulcer. Within one month, 40% of patients receiving placebo experienced ulcer recurrence compared to 0% and 7% of patients receiving lansoprazole 15 mg and 30 mg, respectively. All placebo patients became symptomatic, experienced ulcer recurrence or withdrew from the study by month 9. As compared to placebo, a significantly (P < 0.001) higher percentage of patients treated with lansoprazole 15 mg (83%) and lansoprazole 30 mg (93%) with healed gastric ulcer disease remained healed at month 12. Of patients asymptomatic at baseline, 100% and 59% of those treated with lansoprazole 15 mg and 30 mg, respectively, remained asymptomatic at month 12. The incidence of adverse events was comparable among the treatment groups. Lansoprazole safely and effectively reduces ulcer recurrence in patients with a history of gastric ulcer disease.

2-Pyridinylmethylsulfinylbenzimidazoles↗
PubMed1998

Sonographic prediction of variceal bleeding in patients with liver fibrosis due to Schistosoma mansoni.

Several studies have shown that the characteristic hepatic abnormalities induced by Schistosoma mansoni detectable by ultrasound correlate with the degree of oesophageal varices. So far the value of ultrasound for predicting variceal haemorrhage has not been assessed. Fifty Brazilian patients with schistosomal periportal fibrosis from Alagoas State, 18 of whom had already bled from oesophageal varices, were enrolled in a combined cross-sectional and longitudinal study and investigated clinically, by endoscopy and by ultrasound. Twenty-seven of the patients were monitored until another bleeding episode, death or for a minimum of 28 months. Eight of these patients could be followed up for a further three years. A sonographic score, which accounts for the degree of echogenic periportal thickening and of portal vein dilatation, was calculated for all patients. A highly significant correlation (P < 0.0001) existed between the sonographic score and the occurrence of previous variceal haemorrhage, paralleled by a similar correlation between the sonographic score and the degree of oesophageal varices (P < 0.001). In the 27 patients monitored longitudinally, the sonographic score indicated the risk of future variceal bleeding (P < 0.0001). The sonographic score reliably predicts the risk of variceal bleeding in individual patients with periportal fibrosis. Hence, the application of endoscopy, if available at all in endemic areas, may be restricted to the patients at risk of future variceal bleeding, as determined by ultrasound. Since portable devices can be carried even to remote areas, the application of the proposed score in community surveys could provide a new means for the identification of high-risk patients in S. mansoni-infected populations.

Adolescent↗
PubMed1998

Influence of incubation time and rinsing buffer on the distribution of the tracer lanthanum in canine heart muscle.

Lanthanum (La) is an extracellular tracer, which stains the interstitial space and the cell surface. This study investigates to what extent the distribution of lanthanum in the myocardium of cardioplegically arrested non-ischaemic hearts was influenced by (a) different incubation times in La containing fixative, (b) different kinds of buffer for rinsing and postfixation dilution and (c) different degree of cellular oedema. Myocytes exhibiting La surface staining, with and without intracellular La, were quantified and the volume density of myofibrils (VVMf) as a parameter for the degree of cellular oedema was determined morphometrically. Samples were taken immediately after cardiac arrest induced by coronary perfusion with a cardioplegic solution. Tissue blocks 1 mm3 in size were fixed by immersion for different time periods in a fixation solution containing 1.1% La(NO3)3. Fixation was followed by rinsing in cacodylate or phosphate buffer. The postfixation solution also contained either cacodylate or phosphate buffer. For La detection electron spectroscopic imaging (ESI) and electron energy loss spectroscopy (EELS), was used. Our results show: (i) the volume densities do not differ significantly in specimens rinsed and postfixed in cacodylate or phosphate buffers; (ii) the percentage of myocytes with La surface staining depends on the incubation time in La containing fixative, independent of the rinsing buffer; (iii) the percentage of myocytes with intracellular La correlates significantly with the VVMf; (iv) the incubation time with La containing fixative does not significantly affect the intracellular La staining of slightly swollen cells; and (v) intracellular La distribution patterns differ in cacodylate- and phosphate-buffered specimens. Thus, La tracer methods in conjunction with microanalysis are valuable tools to detect alterations in membrane permeability not visible by conventional transmission electron microscopy (cTEM) in non-ischaemic hearts exhibiting a well preserved ultrastructure.

Animals↗
PubMed1998

RheumaNet--a novel Internet-based rheumatology information network in Germany.

Knowledge transfer in medicine has traditionally been achieved through personal communication, the medical literature, conferences and continuous medical education. However, many of these methods of communication have the problem of currentness, and the latest knowledge is mostly transferred with a certain delay. In particular, chronic disease management is frequently burdened by missing, incomplete or delayed communication. We present the implementation of a novel, Internet-based information system (RheumaNet) to facilitate rapid communication and information transfer between the 21 German Multipurpose Arthritis Centres (MACs). Medical information, agendas, urgent notifications, guidelines, etc., can be exchanged easily via electronic mail, file transfer protocol or the World Wide Web. RheumaNet allows interactive on-line communication as a common platform for joint projects or remote consultation. It supports a set of 'core documentation' that has been used by all German MACs for several years. RheumaNet was used for the organization, on-line presentation and evaluation of the 1997 annual meeting of the German Rheumatology Society and is currently appointed to establish its public representation in the 'Web'. An on-line version of the 'Quality Assurance Textbook' of German rheumatology is achieved with database-derived 'dynamic' Web pages, allowing easy access to any information within it. Advances in the future include the development of on-line patient information bulletin boards, on-line questionnaires, the coordination of rehabilitation and educational tools for medical students, and professional training.

Arthritis, Rheumatoid↗
PubMed1998

Early alterations in intracellular and alveolar surfactant of the rat lung in response to endotoxin.

The aim of this study was to characterize early ultrastructural, biochemical, and functional alterations of the pulmonary surfactant system induced by Salmonella minnesota lipopolysaccharide (LPS) in rat lungs. Experimental groups were: (1) control in vitro, 150 min perfusion; (2) LPS in vitro, 150 min perfusion, infusion of 50 microg/ml LPS after 40 min; (3) control ex vivo, 10 min perfusion; (4) LPS ex vivo, lungs perfused for 10 min from rats treated for 110 min with 20 mg/kg LPS intraperitoneally. Morphometry of type II pneumocytes showed that LPS increased stored surfactant. Lamellar bodies were increased in size, but decreased in numerical density, suggesting that giant lamellar bodies observed in LPS-treated lungs may result from fusion of normal bodies. Structural analysis of alveolar surfactant composition showed that LPS elicited an increase in lamellar body-like and multilamellar forms. Bronchoalveolar lavage (BAL) material from LPS-treated lungs was decreased in phospholipids. BAL bubble surfactometer analysis showed a reduction in hysteresis area caused by LPS. We conclude that LPS leads to alterations of intracellular and alveolar surfactant within 2 h: fusion of lamellar bodies, reduction in surfactant secretion, and changes in alveolar surfactant transformation, composition, and function, which may contribute to the development of respiratory distress.

Animals↗
PubMed1998

Schistosomiasis of the lower reproductive tract without egg excretion in urine.

The individual and public health impact of female genital schistosomiasis (FGS) has been studied and FGS as a risk factor for acquiring human immunodeficiency virus is discussed. In a community-based study in Tanzania, 40% of the women of child-bearing age (n=543) showed excretion of Schistosoma haematobium eggs in the urine (median=2.2 eggs/10 ml of urine) and 32% (n=263) had S. haematobium eggs in their cervical tissue. Urinary and genital schistosomiasis coexisted in 62% of the women, but S. haematobium eggs were found in the cervix without detectable egg excretion in the urine in 23%. Only 43% of the FGS cases had hematuria. Since FGS frequently exists in women with scanty or no egg excretion in the urine and because this disease manifestation is a considerable individual and public health hazard in S. haematobium-endemic areas, mass treatment targeted to women of child-bearing age should be considered.

Acquired Immunodeficiency Syndrome↗
PubMed1998

[Decisions and attitudes of nurses in the care of chronically ill elderly patients].

Data of 182 nurses from two teaching hospitals regarding their attitudes to determinants of the decision-making process in elderly patients in general and decisions in the treatment of an moderately demented, incompetent elderly man with a potentially reversible life-threatening illness using a scenario were analyzed. 68.1 percent complied to the patient's will when an advance directive existed. One fifth reported that the patient's directive was supportive for the decision. The more important the wishes of the patients were evaluated, the more frequent a less aggressive treatment choice was preferred and the less frequent the decision was for resuscitation in the case of a cardiac arrest. The increased use of advance directives is desirable to reduce the number of conflicts in decision-making for healthcare professionals and to reduce the patients' fears of over- or undertreatment and for increasing their possibilities of self-determination. A more intensive integration of topics such as death and dying, treatment of the chronically ill elderly as well as possibilities and limitations of patient directives and their use in the education of nurses is required.

Advance Directives↗
PubMed1998

A web-based risk management and medical-legal curriculum for graduate medical education.

An educational Web site on the topic of risk management and medical-legal issues was designed. The site incorporates a 25-question multiple-choice quiz where resident responses were stored in a database for quantitative analysis. Residents who browsed the educational module scored significantly higher on the quiz (81%) than those who did not (62%). The authors conclude that the Web site and accompanying quiz database offer a practical solution for the uniform delivery of risk management in graduate medical education.

Computer-Assisted Instruction↗
PubMed1997

Acceleration of hepatocellular energy by idebenone during early reperfusion after cold preservation ameliorates heat shock protein 70 gene expression in a pig liver model.

BACKGROUND: Heat shock proteins (HSPs) are induced in the liver after warm ischemia/reperfusion and are thought to be markers of hepatocellular injury and oxidative stress. METHODS: The influence of variable periods of cold storage followed by reperfusion on the expression of HSP70 was studied in the isolated perfused pig liver. Organs were harvested and stored in histidine-tryptophan-ketoglutarate solution at 4 degrees C and then perfused (210 min) in a closed water bath (38 degrees C), which subjects the liver to fluctuating outer pressure. The role of energy depletion, reactive oxygen intermediates, Kupffer cells, and circulating leukocytes in HSP70 expression was determined. RESULTS: HSP70 expression was not detectable in liver tissue before explantation or before reperfusion by Northern blot analysis using a pig HSP70 gene probe. HSP70 expression was observed after reperfusion depending on cold storage time. Kinetics of HSP70 expression monitored by reverse transcriptase polymerase chain reaction showed a rapid increase of mRNA within 1 hr, which was closely associated with delayed recovery of hepatocellular energy charge, as assessed by the ketone body ratio. The inactivation of Kupffer cells, the presence or absence of leukocytes, and the suppression of oxidative stress with the antioxidant idebenone, given during reperfusion, had no influence. However, feeding the animals with idebenone over 7 days before explantation led to a faster recovery of ketone body ratio, paralleled by a substantial suppression of HSP70 expression. CONCLUSIONS: Our data show that HSP70 expression during reperfusion is mainly dependent on the preceding cold storage time and the consecutive delayed recovery of the hepatocellular energy charge.

Animals↗
PubMed1997

Marked genetic differences between stage pTa and stage pT1 papillary bladder cancer detected by comparative genomic hybridization.

Little is known about the genetic changes underlying invasive tumor growth in bladder cancer. Because alterations that are linked to invasive tumor growth may be detectable in minimally invasive (stage pT1) but not in noninvasive (stage pTa) tumors, we searched for genetic differences between 28 pTa and 28 papillary pT1 bladder tumors by comparative genomic hybridization. Losses of 9q (54%), 9p (39%), and Y (28%) and gains of 1q (14%) were most prevalent in pTa tumors. These changes may play a role in the initiation of noninvasive papillary bladder cancer. The total number of aberrations was higher in pT1 tumors (6.5 +/- 5.4) than in pTa tumors (2.3 +/- 2.1; P = 0.0003), suggesting an increased genetic instability at stage pT1. Specific alterations, which were significantly more frequent in pT1 than in pTa tumors (P < or = 0.05), included deletions at 2q (36% of pT1 tumors), 8p (32%), and 11p (21%) and gains at 1q (54%), 8q (32%), 3p, 3q, 5p, 6p, and 10p (18% each). These loci are candidates for carrying genes involved in invasive tumor growth in bladder cancer. High-level amplifications at 1q22-24, 3p24-25, 6p22, 8p12, 8q21-22, 10p12.1-14, 11q13, 12q15-21, 13q31-33, Xp11-13, and Xq21-22.2 may pinpoint the location of oncogenes with relevance for bladder cancer.

Chromosome Aberrations↗
PubMed1997

[Physicians' attitude in the treatment of incompetent patients. Comparison between East and West Germany].

BACKGROUND: Health care decision-making in incompetent severely ill patients presents a number of difficult medical, ethical and legal problems for the physician. The factors and the degree to which various factors contribute to such decisions have rarely been investigated. SUBJECTS AND METHODS: 310 physicians from the state of Baden-Württernberg (Western Germany) and the state of Mecklenburg (eastern Germany) were asked by means of a questionnaire to rate the importance of eight factors in their health care decisions in the elderly. RESULTS: Both, ethical concerns and patients' wishes emerged as the most important factors for decisions in both subsamples. However, significant differences in the degree to which the factors hospital costs, patients' and family wishes, the level of dementia and the patients' age contribute to their decisions could be found between the answers of the doctors of the two lands. CONCLUSIONS: The socialization of the physicians in different health care and social systems seems to be one of the most important reasons for different health care decisions in old and incompetent patients.

Adult↗