Allelic loss at 1p is associated with tumor progression of meningiomas

Next to chromosome 22 anomalies, deletions of the short arm of chromosome 1 have previously been described as the most frequent alteration detected by cytogenetic analysis of meningiomas. To determine the incidence of these deletions, we have analyzed a series of 50 meningiomas for the loss of alleles at four chromosome 1 loci. Thirteen samples displayed LOH for the markers studied; in one instance, the results were compatible with loss of the entire chromosome 1, whereas in the other 12 samples deletions of the short arm were observed. Eleven of the meningiomas had previously been shown to have loss of alleles on chromosome 22, and 12 of them were characterized by increased tumor aggressiveness. These findings suggest that deletion of Ip (or the alteration of a locus located there) might represent a secondary, but nonrandom alteration in meningiomas, perhaps contributing to meningioma tumor progression.     

Regulation of cellulase gene expression in the filamentous fungus Trichoderma reesei

Basic features of regulation of expression of the genes encoding the cellulases of the filamentous fungus Trichoderma reesei QM9414, the genes cbh1 and cbh2 encoding cellobiohydrolases and the genes egl1, egl2 and egl5 encoding endoglucanases, were studied at the mRNA level. The cellulase genes were coordinately expressed under all conditions studied, with the steady-state mRNA levels of cbh1 being the highest. Solka floc cellulose and the disaccharide sophorose induced expression to almost the same level. Moderate expression was observed when cellobiose or lactose was used as the carbon source. It was found that glycerol and sorbitol do not promote expression but, unlike glucose, do not inhibit it either, because the addition of 1 to 2 mM sophorose to glycerol or sorbitol cultures provokes high cellulase expression levels. These carbon sources thus provide a useful means to study cellulase regulation without significantly affecting the growth of the fungus. RNA slot blot experiments showed that no expression could be observed on glucose-containing medium and that high glucose levels abolish the inducing effect of sophorose. The results clearly show that distinct and clear-cut mechanisms of induction and glucose repression regulate cellulase expression in an actively growing fungus. However, derepression of cellulase expression occurs without apparent addition of an inducer once glucose has been depleted from the medium. This expression seems not to arise simply from starvation, since the lack of carbon or nitrogen as such is not sufficient to trigger significant expression.     

Glutathione movements during cold preservation of rat hepatocytes

PURPOSE: Power-Doppler sonography is regarded as a very sensitive method for detecting low-velocity and low-volume blood flows. The purpose of our study was to investigate whether increased vascularity in breast carcinoma can be visualized by power-Doppler sonography and whether new criteria for differentiating benign and malign lesions can be found. METHOD: 315 patients were examined with a 13-MHz high-resolution linear transducer. If a suspicious lesion was found, it was evaluated further by power-Doppler sonography. Compared to normal breast parenchyma (reference structure), a focal increase in blood flow signals was registered using a 3-step grading system with a 4th step for no flow increase. RESULTS: In 97 cases the sonographic findings were correlated with histology (n = 95) or cytology (n = 2). There were 50 benign lesions, 42 cases of invasive and 5 cases of in-situ carcinoma. 73.5% benign lesions showed no or just minimal increases in flow signal. 81% of invasive cancer presented middle- or high-flow increases compared to normal breast parenchyma. The extend of flow increase was linked to tumor size in invasive cancer. In stage T1b to T4, 94.3% of invasive carcinoma presented middle or high flow increases. CONCLUSION: Power-Doppler sonography is able to visualize vascularization in breast tumors. According to first clinical results PD sonography is a promising additional diagnostic tool which seems to offer new criteria for differential diagnosis in breast tumors.     

Rhesus brain gas tension and learned task performance responses to normoxic and hyperoxic breathing

The impact of extended exposure to 21 and 100% O2 breathing mixtures on brain tissue oxygenation and performance of a learned task was studied in seven rhesus monkeys. Trained in the Sidman Avoidance Task, the animals were exposed to either breathing mixture for a period of 3.5 h in which brain tissue PO2, PCO2, and PN2 were observed. With 100% O2, PO2 and PCO2 rose significantly (less than 0.01 and less than 0.05, respectively) above control levels while PN2 fell significantly (less than 0.01) below its baseline value. With 100% O2 no statistically significant difference in gas tension values was shown for performance vs. nonperformance conditions. There was no difference in the number of shocks received with either breathing mixture. Lever press response frequency decreased throughout the experiment for both groups. During the last performance session, response frequency for the 100% O2 group leveled off, whereas for the 21% O2 group it continued to decrease.     

Experimental Bacteroides fragilis endocarditis in rabbits

A serum-resistant strain of Bacterioides fragilis that did not produce heparinase was used to study the characteristics of B. fragilis endocarditis in the rabbit experimental model. The infective dose required to produce endocarditis in 50% of rabbits was significantly lower for rabbits with left-sided intracardiac catheters (log10 6.3 colony-forming units +/- 0.6/ml) as compared with right-sided intracardiac catheters (log10 7.7 colony-forming units +/- 0.8/ml). After 3 days of infection, bacterial titers of the tricuspid vegetations were significantly lower than titers of aortic vegetations (P less than 0.01), although at 5 days the titers were similar (P greater than 0.05). The weights of tricuspid vegetations, although similar at 3 days (P less than 0.05). There were no spontaneous deaths during 12 days of infection. In rabbits with the catheter removed before infection, bacterial titers were similar to those titers in rabbits with the catheter continuously in place. This model will permit study of various drug regimens for treatment of this disease.     

Systemic candidiasis in infants: a case presentation and literature review

A 4 1/2-month-old male infant with systemic candidiasis had anuria secondary to Candida albicans fungus balls impacted in the renal pelves. The patient was treated with temporary urinary diversion, amphotericin B, and flucytosine. Six weeks after therapy had been concluded, the patient had C albicans arthritis of the right hip and responded to a second course of amphotericin B and flucytosine therapy. This article discusses immunologic evaluation and presents a literature review.     

neu/erbB-2 amplification identifies a poor-prognosis group of women with node-negative breast cancer. Toronto Breast Cancer Study Group

PURPOSE: It remains a challenge to predict which women with axillary node-negative (ANN) breast cancer at greatest risk of relapse may benefit most from adjuvant therapy. Increases in neu/erbB-2 have been implicated in breast cancer prognosis. Although overexpression has been investigated extensively, this study represents the first prospective assessment of the prognostic value of neu/erbB-2 DNA amplification in a cohort of women with newly diagnosed ANN. METHODS: A consecutive series of women was monitored for recurrence (median follow-up duration, 36 months) and tumors from 580 individuals were analyzed for amplification. The association of amplification with risk of recurrence was examined in survival analyses with traditional and histologic markers as prognostic factors. RESULTS: Neu/erbB-2 was amplified in 20% of cases. We found an increased risk of disease recurrence when neu/erbB-2 was amplified > or = twofold that persisted with adjustment for other prognostic factors (relative risk, 2.36; P = .002). We found some evidence that amplification was more important in patients who received chemotherapy compared with untreated patients. CONCLUSION: neu/erbB-2 amplification is an independent prognostic factor for risk of recurrence in ANN breast cancer. Women with tumors without neu/erbB-2 amplification have a good prognosis; aggressive therapy in this group is therefore difficult to justify. On the other hand, even with adjuvant chemotherapeutic treatment, women whose tumors exhibit neu/erbB-2 amplification have an increased risk of recurrence. We encourage a randomized trial to compare more aggressive adjuvant chemotherapy versus standard chemotherapy for ANN women whose tumors exhibit neu/erbB-2 amplification.