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A Marx

Publications and source records attributed to A Marx.

At least 181 records · Page 10Linked to original sources
PubMed1992

Well-differentiated thymic carcinoma. An organotypical low-grade carcinoma with relationship to cortical thymoma.

Based on a study of 26 cases, the well-differentiated thymic carcinoma is described as a distinct organotypical carcinoma of the thymus with low-grade malignancy. It is characterized by a predominance of epithelial cells with usually low mitotic rate, an epidermoid differentiation with slight to moderate cytological atypia, the constant presence of interepithelial immature cortical thymocytes, lobular growth, and formation of epithelial palisades around perivascular spaces. The tumor occurs at age 14 to 76 years in both sexes. An association with myasthenia gravis is found in 77% of the patients, and 83% of the tumors show invasion of adjacent organs or endothoracic metastasis at primary operation. This rate is higher than in cortical thymomas (47%) but lower than in other thymic carcinomas (92%). Two of 18 patients with follow-up died of tumor recurrence and pleural metastasis. Well-differentiated thymic carcinoma can be related to cortical thymoma by common morphological features and a similar immunophenotype of epithelial cells. It must be differentiated from the lymphocyte-depleted cortical thymomas after corticosteroid treatment and from the benign epithelial-rich medullary thymomas.

Adolescent↗
PubMed1992

[1989 Basel Mammography Action].

To evaluate the compliance for a breast cancer screening program in the region of Basel, a mammography and a clinical examination has been offered free of charge to women between 40 and 60 years of age, especially to women with familial breast cancer. From September to November 1989, 602 women participated. Results were obtained from an epidemiologic questionnaire and a two-view mammography. The median age was 55.1 years. 70.2% of the women never had a mammography before. 28.8% indicated a history of familial breast cancer. So far 444 women have been evaluated. No pathological results were obtained in 84.8% In 10.7% a second examination has been recommended in the near future. In 4.5% the mammography led to an aspiration biopsy or surgical lumpectomy where 5 (1.2%) neoplasms have been detected. Due to the limited duration of the campaign and the invitation especially addressed to women at risk, our results are not comparable with large-scale screening campaigns known from the literature. Nevertheless, we succeeded to sensitize the female population for this kind of breast care. The overwhelming success shows that the basis for a large-scale screening program may exist.

Adult↗
PubMed1992

Genomic organization and lack of transcription of the nicotinic acetylcholine receptor subunit genes in myasthenia gravis-associated thymoma.

To investigate the relationship between anti-acetylcholine receptor (AchR) autoimmunity and the occurrence of thymoma in a particular group of myasthenia gravis (MG) patients we analyzed DNA and RNA from MG-associated thymomas and control tissue by Southern and Northern blotting, respectively, using the AchR alpha, beta, gamma, delta and epsilon-subunit cDNAs or oligonucleotides as probes. Restriction analysis of genomic DNA showed an organization of AchR subunit genes in thymomas identical with that of normal tissues. In particular, in thymomas, there was no deletion of exon 4 of the alpha-subunit which encodes the main immunogenic region of the AchR. Dot and Northern blot analysis did not reveal transcription of any AchR subunit gene in thymomas. Instead, an RNA nucleotide sequence was identified in MG-associated thymomas that hybridized to an AchR oligonucleotide probe coding for amino acids 371-378 of the AchR alpha-subunit. With this sequence as a probe, three DNA restriction fragments in addition to a restriction fragment of the AchR alpha-subunit gene could be identified in the human gene. The findings suggest that proteins with extensive homology to the AchR are not expressed in MG-associated thymomas. However, there are three genomic loci in thymoma genomes with a very restricted homology to the AchR alpha-subunit gene. One of these loci might code for the cross-reacting AchR epitope detected in almost all MG-associated thymomas in contrast to thymomas without MG.

Adult↗
PubMed1992

[Proximal femoral fractures. Is there an indication for the condylar screw (DCS)?].

Between 1983 and 1989 66 consecutive fractures of the proximal femur were treated with a condylar screw DCS. 42 patients were available for a follow-up study, 12 subtrochanteric fractures (mean age 58.5 years) and 30 intertrochanteric fractures (mean age 73 years). The primary union rate was clearly higher in the subtrochanteric group (10/12) compared to the intertrochanteric group (22/30). All the 8 implant complications (pull-out, metal fatigue) in the intertrochanteric group were associated with important posteromedial comminution in elderly patients who cannot be mobilized with only partial weight bearing postoperatively. Unstable intertrochanteric fractures in elderly patients should not be treated with the DCS. These are indications for the DHS which allows controlled telescoping. The indication for the DCS is limited to proximal shaft fractures in younger patients capable of partial weight bearing.

Adult↗
PubMed1992

[Donor allopurinol treatment improves organ preservation of the kidney also when using UW solution].

Kidney function following hypothermic preservation with Eurocollins (EC) was previously shown to be improved by donor treatment with Allopurinol (AP) [1]. The University of Wisconsin organ preservation solution (UW), however, contains Allopurinol (1 mM). A syngeneic rat kidney transplant model was used to investigate concurrent Allopurinol donor-pretreatment (40 mg/kg b.w.). Kidney graft function resulted to be improved by AP pretreatment following organ preservation with both EC or UW as evidenced by significant reduction in serum creatinine values. On day two following transplantation the respective serum creatinine values (mumol/l) with and without AP-pretreatment were 424 +/- 39 and 662 +/- 25 for EC, and 259 +/- 48 and 387 +/- 48 for UW organ preservation. Furthermore survival- and histology-data were also superior for recipients of kidney grafts from AP-pretreated donors. We conclude that Allopurinol concentration in the UW solution might be to low or that adding AP into an organ storage solution is not the best application modality.

Adenosine↗
PubMed1991

[Atraumatic Clostridium septicum infection in granulocytopenia].

A fatal Clostridium septicum infection occurred in three patients. Case 1. A 55-year-old man died of septicaemia resulting from granulocytopenia of uncertain aetiology; it was associated with perforation of ileal mucosal ulcers. Autopsy revealed neutropenic enterocolitis and diffuse gas formation, especially in the brain, caused by Clostridium septicum. Case 2. A 18-year-old boy developed a caecal invagination during imipenem-induced granulocytopenia. A fulminant postoperative Clostridium septicum infection ended fatally. At autopsy many ulcers were found at the site of invagination with gas formation involving all organs. Case 3. Myonecrosis of the left arm, caused by Clostridium septicum, developed without external cause in a 12-year-old girl with congenital neutropenia. Despite aggressive surgical intervention she died of toxic shock. Autopsy revealed caecal mucosal ulcers as the portal of entry of Clostridium septicum.

Adolescent↗
PubMed1991

Sodium and potassium channels in epithelial cells from thymus glands and thymomas of myasthenia gravis patients.

In both normal and neoplastic epithelial cells from human thymus glands and thymomas, respectively, we found voltage-gated sodium and potassium channels that resemble the adult-type Na channel and the delayed outward rectifier K channel, respectively, of human skeletal muscle and mammalian nervous system. These voltage-gated ion channels might be part of a communication system between epithelial cells and other components of the microenvironment of the thymus.

Electric Conductivity↗
PubMed1991

Absence of acetylcholine-induced current in epithelial cells from thymus glands and thymomas of myasthenia gravis patients.

We investigated the activity of ion channels in epithelial cells from human thymus glands and thymomas kept in short-term cell culture by clamping the membrane potential of the cells at -85 mV and determining the membrane current flowing on application of acetylcholine, glycine, or gamma-aminobutyric acid. In concentrations of up to 10(-3) M, none of the neurotransmitters induced any detectable current. This suggests (1) that there are no acetylcholine receptors (AChRs) or other products of the AChR gene family having ion-channel properties in the membranes of these epithelial cells, and (2) that the alpha-bungarotoxin-binding protein of thymus and thymoma has no AChR-like ion-channel property. These results support the hypothesis that the cross-reacting structures that elicit the anti-AChR autoimmune response in thymoma-associated myasthenia gravis are antigens having only limited homology with the AChR. Myasthenia gravis not associated with thymoma might have a different pathogenesis.

Acetylcholine↗
PubMed1991

Nitrate contamination of drinking water: evaluation of genotoxic risk in human populations.

Nitrate contamination of drinking water implies a genotoxic risk to man due to the endogenous formation of carcinogenic N-nitroso compounds from nitrate-derived nitrite. Thus far, epidemiological studies have presented conflicting results on the relation of drinking water nitrate levels with gastric cancer incidence. This uncertainty becomes of relevance in view of the steadily increasing nitrate levels in regular drinking water supplies. In an attempt to apply genetic biomarker analysis to improve the basis for risk assessment with respect to drinking water nitrate contamination, this study evaluates peripheral lymphocyte chromosomal damage in human populations exposed to low, medium, and high drinking water nitrate levels, the latter being present in private water wells. It is shown that nitrate contamination of drinking water causes dose-dependent increases in nitrate body load as monitored by 24-hr urinary nitrate excretion in female volunteers, but this appears not to be associated with peripheral lymphocyte sister chromatid exchange frequencies.

Body Burden↗
PubMed1991

Protective effect of allopurinol and superoxide dismutase in renal isografts in cyclosporin A-treated rats.

Acute tubular necrosis (ATN) after renal transplantation is related to the duration of warm and cold ischemia and leads to temporary or permanent impairment of graft function. An increased incidence of ATN has been reported since the introduction of cyclosporin A. Kidney damage resulting from hypothermic storage is generated in part during reperfusion rather than during ischemia itself. Potential mediators of the reperfusion injury are oxygen-derived free radicals. Therefore, the influence of two oxygen radical antagonists, allopurinol and superoxide dismutase, was evaluated in syngeneic rat kidney transplantation with and without concurrent administration of cyclosporin A. At 15 h cold ischemia, 28-day survival increased from 8% (no treatment) to 22% (superoxide dismutase), 33% (superoxide dismutase and allopurinol), and 73% (allopurinol). Cyclosporin A cotreatment (10 mg/kg over 14 days) resulted in survival rates of 0%, 25%, 17%, and 50% for the respective treatment groups. The results of serum creatinine values and morphological evaluation of biopsies paralleled the survival rates. Cyclosporin A nephrotoxicity was evidenced by significant serum creatinine elevations throughout the 28-day period of observation. In conclusion, allopurinol significantly protects syngeneic rat kidney transplants against a critical duration of cold ischemia. Under the conditions of this experiment, allopurinol was clearly superior to superoxide dismutase treatment. Cyclosporin A nephrotoxicity was, however, not ablated by the oxygen radical antagonists employed.

Allopurinol↗
PubMed1991

[6 years experiences with the "dynamic condylar screw" in supra- and intercondylar fractures].

44 supra- and intercondylar fractures were treated with the "Dynamic Condylar Screw" (DCS). Our experience with this device in a teaching hospital with surgeons of different training levels was encouraging, since there was no complication due to the insertion technique in this complex fracture setting. When we compare our results obtained with the DCS with those in the literature achieved with the angled blade plate, we got the same or better results in respect to implant failure, infection, fracture healing and function.

Adolescent↗
PubMed1991

[External fixator as primary and definitive treatment of tibial fracture with severe soft tissue damage].

The initial treatment of choice of fractures with severe soft tissue damage of the leg is the stabilization with an external fixator. After successful healing the question arises whether to continue the initial treatment with the external fixator to bone union or to change the initial concept by an internal fixation. Our experience with 62 fractures of the tibia (follow-up of 59 fractures) from 1985 to 1989 shows that 72% of the fractures were healed by the external fixator alone. Delayed union or pseudoarthrosis occurred in 17% and were mostly treated by late internal fixation. An analysis of the fracture types (new AO classification) did not show certain fracture types, that did not respond to the external fixator treatment alone. We conclude that the reason for a delayed union or pseudoarthrosis is less a morphological than a biological one. We recommend the first and final external fixator as treatment for fractures with severe soft tissue damage of the leg.

External Fixators↗
PubMed1991

[Is cecostomy still current for emergency relief of the colon?].

The policy of treatment in patients with acute obstruction of the left colon remains controversial. One-stage emergency colectomy and primary anastomosis is usually recommended. Is a multiple-stage approach with primary blowhole cecostomy still a valuable solution? This retrospective analysis of 117 patients with emergency cecostomies shows an overall perioperative mortality and morbidity which are favourable compared with those reported in series of similar cases treated by one-stage procedures. In all patients the colon obstruction was treated effectively by the cecostomy. Only two of the stoma-related complications required operative intervention. The second operation was performed after a mean interval of 12 days. The low perioperative mortality of 2.1% shows, that the time was successfully used to optimize the perioperative conditions. It is concluded that patients with a very poor risk may profit by preliminary decompression by blowhole cecostomy.

Aged↗
PubMed1991

[Surgical indications, choice of procedure and results in upper gastrointestinal hemorrhage].

Even today acute upper gastrointestinal bleeding carries a high mortality rate. To improve results it is important to define and operate on those patients in whom recurrent bleeding is expected. Whenever possible early elective surgery is recommended. To improve long-term results we propose definitive ulcer surgery even in patients presenting as emergencies. Implementation of this policy does not increase operative mortality.

Duodenal Ulcer↗
PubMed1990

[A year experience with extracorporeal shockwave lithotripsy of gallstones].

43 patients with symptomatic gallbladder stones were treated by extracorporeal shockwave lithotripsy and oral bile acids. In all patients the stones were successfully fragmented during the first lithotripsy session. 33 patients underwent 2-4 treatment sessions. In 16 out of 43 patients the stones disappeared within 7.9 months. The rate of stone dissolution was dependent on the number and size of stones. 3 patients required surgery because of frequent colic in one case, cholecystitis in one case and lack of cooperation in one case. No important side effects were noted except mild pancreatitis 3 weeks after lithotripsy in one patient. Results at this center of extracorporeal shockwave lithotripsy combined with oral bile acids indicate that this treatment may become an alternative to cholecystectomy in patients with a small number (less than 3) of stones not exceeding 30 mm in diameter.

Adult↗
PubMed1990

Microtubule assembly and oscillations induced by flash photolysis of caged-GTP.

Microtubule assembly and oscillations have been induced using the rapid liberation of GTP by UV flash photolysis of caged-GTP and monitored by time-resolved X-ray scattering. The flash photolysis method of achieving assembly conditions is much faster than the temperature jump method used earlier (msec vs. s range). However, the structural transitions and their rates are similar to those described previously. This means that the rates of the transitions in microtubule assembly observed before are determined by the protein itself, and not by the rate at which assembly conditions are induced. The advantages and limitations of using the photolysis of caged-GTP in microtubule assembly studies are compared with temperature jump methods. Caged-GTP itself reduces the rate of microtubule assembly and oscillations at mM concentrations, consistent with a weak interaction between the nucleotide analogue and the protein. X-rays are capable of slowly liberating GTP and other breakdown products from caged-GTP, even in the absence of UV flash photolysis, thus causing an apparent "X-ray-induced" microtubule assembly. This effect depends on the X-ray dose but is independent of the caged-GTP concentrations used here (mM range), suggesting that the breakdown of caged-GTP is caused not by the direct absorption of X-rays by the compound but by another intermediate reaction such as the generation of radicals by the X-rays.

Animals↗
PubMed1990

Absence of the Epstein-Barr virus genome in the normal thymus, thymic epithelial tumors, thymic lymphoid hyperplasia in a European population.

It has previously been shown that the Epstein-Barr virus (EBV) genome may be detected in some thymic tumors. We have investigated specimens of normal thymus, thymitis with lymphoid hyperplasia and a large spectrum of thymic epithelial tumors obtained from european patients for the presence of EBV genome by in situ hybridization and DNA-blotting methods. Cell lines established from seven of the thymic tumors were also tested for EBV. No EBV genome was demonstrated in any of the tumors examined, which included various types of thymoma and thymic carcinomas, nor in the non-neoplastic thymic specimens. However, unlike previous reports, no examples of lymphoepithelial-like thymic carcinoma, nor specimen from Asian patients were included in this study. We suggest that EBV is linked to a specific epithelial tumor type, namely the lymphoepithelial-like carcinoma, regardless of its site, and not to thymic tumors in general.

Adolescent↗