A poorly differentiated germ cell tumor (seminoma) in a Long Evans rat

A large neoplasm that replaced 1 testis of a Long Evans Rat was noted at the final necropsy of a dietary 2-yr study. By light microscopy, the morphological features were consistent with a poorly differentiated seminoma. Ultrastructurally, the cells were polygonal, had a round nucleus, had straight cellular boundaries, and bore no resemblance to Sertoli cells. Although there was little evidence of spermatocytic differentiation, the presence of proacrosomal granules and vesicles, prominent Golgi apparatus, tight intercellular junctions, and a few centriolar pairs without axoneme development, in conjunction with the absence of lipid droplets or abundant smooth endoplasmic reticulum, supported the diagnosis of seminoma rather than Leydig cell tumor. The cells were S-100- and vimentin-positive, although cytokeratin- and alpha-fetoprotein-negative. Seminomas are extremely rare neoplasms in rats; this is the first report in this strain and the first extensive analysis of a rat seminoma without spermatocytic differentiation.

NADPH-oxidase expression and in situ production of superoxide by osteoclasts actively resorbing bone

Recent reports have suggested that production of superoxide or other reactive oxygen species by activated osteoclasts may play a role in the complex process of bone resorption; however, the enzyme responsible for production of superoxide by osteoclasts has not been characterized. To determine if osteoclasts express NADPH-oxidase, a superoxide-generating enzyme found in phagocytic leukocytes, immunohistochemical studies were performed on tibia from 1-5-d-old rats using mAbs 449 and 48 and an antiserum specific for p47-phox. These antibodies recognize epitopes on the alpha and beta subunits of cytochrome b558, respectively, and the p47 cytosolic component of NADPH-oxidase. We found that osteoclasts attached to bone surfaces in tibia expressed all three components, as did mature polymorphonuclear and some mononuclear leukocytes in the bone marrow. In many adherent osteoclasts, the cytochrome b558 subunits were localized to the ruffled-border and bone interfaces. Studies were also performed on mature rat tibia that had undergone controlled fracture. By two weeks the healing fractures develop a callus rich in actively resorbing osteoclasts. Osteoclasts within the calluses, and attached to bone surface, also expressed the cytochrome b558 proteins. In addition to demonstrating the expression of NADPH-oxidase, the active production of superoxide by osteoclasts was also demonstrated in situ in freshly isolated tibia using 3,3'-diaminobenzidine (DAB)-Mn2+, a histochemical method specific for superoxide localization. Osteoclasts attached to bone surfaces contained deposits of oxidized DAB which were observed by light microscopy. Nonstimulated polymorphonuclear and mononuclear leukocytes in the bone marrow did not contain DAB deposits unless stimulated with phorbol myristate acetate, a known activator of NADPH-oxidase. These findings indicate that osteoclasts contain NADPH-oxidase, and during the process of resorbing bone, are actively producing superoxide.

The DAB-Mn++ cytochemical method revisited: validation of specificity for superoxide

We wished to assess whether the previously developed 3,3'-diaminobenzidine (DAB)-Mn++ cytochemical method, purportedly specific for superoxide localization, is detecting superoxide O2.- and/or the superoxide product, O2(1 delta g). We show here that polymorphonuclear leukocytes (PMNs) produce O2(1 delta g) extracellularly in response to non-phagocytic stimuli and that this production is inhibited by addition of superoxide dismutase, an enzyme typically used to demonstrate that a reaction is mediated by O2.-. Because O2(1 delta g) is highly reactive and can be generated from O2.-, the reactivity of a pure chemical source of O2(1 delta g) with the cytochemical probe DAB was examined in the presence and absence of Mn++. Reactions between DAB and O2(1 delta g), thermally released from 1,4-dimethyl-napthalene-1,4-endoperoxide (DNE), indicated that O2(1 delta g) directly reacted with DAB, forming an insoluble DAB polymer, and that this reaction was increased by the presence of Mn++. The direct reaction of O2(1 delta g) with DAB was confirmed using near-IR emission spectroscopy. The near-IR emission spectrum of DNE as it was warmed showed the characteristic energy emission peak of O2(1 delta g) and the intensity of this peak was reduced by the addition of DAB; kq = 1.7 x 10(8) M-1 sec-1. The requirement of Mn++ for oxidation of DAB by O2.- was reconfirmed using potassium superoxide as a pure chemical source of O2.-. In cell studies, however, DAB deposits were not observed in PMNs stimulated under conditions that lead to O2(1 delta g) production [e.g., 0.040 or 0.162 microM 4B-phorbol-12-myristate-13-acetate (PMA)], regardless of whether Mn++ was present in the cytochemical medium. Nor were DAB deposits found in cells stimulated with PMA in the absence of Mn++ or in unstimulated PMNs. Only cells incubated in cytochemical medium containing Mn++ and stimulated to produce large amounts of O2.- (e.g., 3.24 microM PMA) contained DAB deposits. In summary, the DAB-Mn++ cytochemical method remains an excellent method for localizing the production sites of O2.-, since the concentration of O2(1 delta g) within vesicles of stimulated cells is too low to directly oxidize DAB to an electron-dense deposit.

[Conservative treatment of peptic esophageal stenoses. Results of a prospective long-term study]

In a prospective long-term study the feasibility of conservative management of peptic oesophageal stenosis was investigated. Admission criteria were: endoscopic-bioptic evidence of peptic stricture of the oesophagus, acid gastro-oesophageal reflux on pH-metry, high operative risk or previous unsuccessful antireflux operation. Therapy consisted of two components: 1. bouginage of the stricture up to 38 to 45 French; 2. inhibition of gastric secretion by 4 X 400 mg daily cimetidine. A total of 33 patients were entered into the study; 28 were followed up for more than 6 months, the mean follow-up period being 15 months. Out of the 28 patients 16 were clinically free of symptoms, 5 had evident symptoms, 3 needed rebouginage and the remaining 4 were clear failures and had to be operated on because of persistent severe pain or rapid restenosis. Considerable improvement in reflux oesophagitis was obtained in 61.5% of cases; indeed, complete healing was noted in 46% of patients at follow-up. Both the clinical and endoscopic outcome were influenced by compliance. Irregular taking of cimetidine impaired results significantly (p less than 0.001 X2-test) and raised the frequency of rebouginage. These results show that 86% of cases with the most severe form of reflux oesophagitis were managed successfully by conservative therapy and that only the remaining few cases needed surgery.

Long-term treatment of peptic esophageal stenosis with dilatation and cimetidine: factors influencing clinical result

Surgical treatment of severe peptic esophageal strictures is a serious problem in high-risk cases. Conservative treatment has to be considered as an alternative. In a prospective study, 33 patients were treated with dilatation of the stricture and a long-term medication with 4 X 400 mg cimetidine from 1977 to 1982. 28 patients were followed up for 6 months--6 years. 16 patients showed a good result (clinical stages I and II). 5 patients needed no further dilatation, but had significant symptoms (stage III). 4 patients had to be operated on because of serious symptoms and rapid restenosis. The clinical result was significantly less favorable in patients who took cimetidine irregularly or discontinued it (p less than 0.001) than in patients with good compliance. In addition, the result of endoscopy was poorer in poor compliance and the frequency of bougienage was greater than when cimetidine was taken regularly. Age, sex or initial length and diameter of the stricture did not significantly influence the outcome. We conclude that conservative treatment of peptic esophageal strictures yields good long-term results in 85% of patients, provided that a high dose of cimetidine is taken on a life-long basis.

[Functionally satisfying reconstruction of a combined abdominal, chest wall and diaphragmatic defect with corium following sternum tumor resection]

In a patient, suffering from a chondrosarcoma in the lower sternum, and having undergone radical tumor resection, we had to reconstruct the thoracic wall, the abdominal wall, and the diaphragm. This was done with autologous corium. We report on the advantages of this material and at the same time refer to that of a complete physiologic reconstruction of the diaphragmatic dome seems impossible if accompanied by defects of the thorax and the abdominal wall. Fitting a corset appears necessary as an external support.

[Results of the distal splenorenal Warren shunt (author's transl)]

From May 1st 1977 until the end of December 1980 35 Warren shunts were performed upon unselected patients with portal hypertension and esophageal varices. According to the Child classification they were divided up into nine Child A, 21 Child B and five Child C cases. Five (14.3) postoperative deaths occurred, yet only one due to technical failure; three patients died of hepatic coma and one of a perforated gastric ulcer. As a postoperative complication recurrent bleeding occurred in six cases (17.1%). Not even one case of pancreatitis could be observed. Fifteen patients were examined at least 6 months after operation. The control angiography (n = 15 = 100%) revealed hepatofugal circulation in only one case; splenomegaly was reduced in ten cases. Only one patient showed clinical signs of encephalopathy, fourteen patients were able to return to their normal activities. The late thrombosis rate was very low-only one case; however, the possibility of conversion to a portocaval shunt remains.