Fusion of bone marrow-derived stem cells with cardiomyocytes in a heterologous in vitro model.

OBJECTIVE: Recent studies have demonstrated that transplanted bone marrow-derived stem cells (BMCs) possess a broad differentiation potential and are able to form new cardiomyocytes. However, the identity of BMCs as true cardiomyocytes is still ambiguous. Therefore, we investigated the fate of transplanted fluorescence labeled BMCs and cardiomyocytes in co-culture. METHODS: For cell tracking we used two different fluorescent probes, Vybrant/DiO and Vybrant/DiI. BMCs were taken from human sternal marrow, purified using a Ficoll-gradient-centrifugation, treated with 5-azacytidine and stained with Vybrant/DiO. Furthermore, isolated spontaneous beating cardiomyocytes of neonatal rats (CM) were labeled with Vybrant/DiI. Thereafter, the BMCs were transplanted into CM-cultures and investigated on day 1, 4, 7, 14 and 28 using two-color fluorescence phenotyping by laser-scanning-cytometry (LSC). Two-color positive cells were harvested by patch-clamp technique and beta-MHC mRNA expression was analyzed by single-cell PCR. RESULTS: Two different morphological phenotypes were observed by LSC. First, isolated DiO labeled BMCs without contact or with direct cell contact to DiI labeled CMs. Second, some BMCs and CMs were double positive for DiO/DiI spontaneously forming hybrids. This population increased by 18% from day 1 to 4 and decreased only slightly until day 28. Additionally, few two-color positive cell formations expressed both human and rat specific beta-MHC mRNA as well as only human beta-MHC mRNA indicating that cell-fusion and transdifferentiation has occurred. CONCLUSION: These observations provide in vitro evidence for spontaneous cell fusion and transdifferentiation of BMCs in co-culture, raising the possibility that the observed phenomenons may contribute to development or maintenance of these cell types.     

Intraoperative management of penile erection with intracorporeal phenylephrine during endoscopic surgery

Intraoperative penile tumescence during endoscopic surgery is a troublesome complication that often is refractory to recommended methods of management. We report a new approach of pharmacological management with intracorporeal penile injections of phenylephrine (total dose of 0.1 mg.), which was successful in 3 successive patients. This approach is prompt, safe and reproducible, and it provides sustained resolution of erection without systemic side effects. It is concluded that local intracorporeal penile administration of this sympathomimetic agent appears to be a potent new tool in the armamentarium of the endoscopic surgeon dealing with this frustrating clinical situation, which merits further clinical trial.     

Suramin inhibits bone resorption and reduces osteoblast number in a neonatal mouse calvarial bone resorption assay.

The antineoplastic properties of suramin, a polyanionic agent with demonstrated antigrowth factor activity, are under evaluation in vitro, in vivo, and in clinical trials. Suramin has been shown to have antitumor activity in patients with advanced, hormone refractory prostate cancer. During these trials, significant resolution of osseous pain was observed in nearly three quarters of the patients treated with suramin. To evaluate the effect of suramin on bone cells, we studied the effect of suramin on bone resorption in a neonatal mouse calvarial assay. Suramin inhibited bone-resorbing activity in a dose-related fashion and had an additive effect with calcitonin. Calvaria pretreated with suramin had less bone-resorbing activity, fewer attached osteoblasts, and less medium alkaline phosphatase activity than control calvaria. Suramin also inhibited osteoclastic release of tritiated proline from labeled bone in a dose-dependent fashion. The effect of metastatic prostate carcinoma on bone is incompletely understood, but may be moderated by tumor-produced factors and/or cytokines. The effects of several such agents, therefore, were examined in combination with suramin. Bone resorption induced by PTH, epidermal growth factor, tumor necrosis factor, and a tumor-produced factor, PTH related-protein, was blocked by suramin. The ability of suramin to inhibit the bone-resorbing effects of several cytokines suggests that its mechanism may involve direct action on bone metabolism. Autoradiography performed on calvaria treated with labeled suramin demonstrated heavy deposition of suramin on the outer surface of the matrix, adjacent to osteoblasts and osteoclasts lining the outer table, suggesting that bone cells may be subject to high local concentrations of the drug, in keeping with this hypothesis.     

Diagnostic problems in local recurrence after breast saving treatment]

353 patients with stages pTis, pT1-2, pN0-1, cM0 breast cancer have been treated consecutively by breast conserving therapy in a prospective, nonrandomized study at the University Hospital Basel and the Women's Clinic Rheinfelden/Baden/Germany. The median age was 47 years, the median follow-up time 67 months, and 4% only of this collective were lost to follow-up after a median time of 42 months. In 79% of the cases the tumor was excised totally, while in 19% the resection margins were positive and in 2% only the margins were not available for histological judgement. The rate of local failure reached 8% with a median time interval of 53 months. 116 patients showed postactinic induration in the primary tumor region. 73 of these were given additional diagnostic examination: The postactinic induration was judget clinically suspicious in 51 cases and clinically nonsuspicious of local failure in 22 cases. All 73 patients received additional examination by mammography and biopsy. By comparison with the histological results the clinical results were correct in 59% and false in 41%, while the mammographic results were correct in 82% and false in 18% of the cases.     

Differential effect of catechol-O-methyltransferase Val158Met genotype on emotional recognition abilities in healthy men and women.

The catechol-O-methyltransferase (COMT) Val158Met polymorphism modulates executive functions and working memory and recent neuroimaging studies implicate an association with emotional processing. We examined the relationship between the COMT Val158Met polymorphism and facial emotion recognition and differentiation in 100 healthy individuals. Compared to Met homozygosity, Val homozygosity was associated with better and faster recognition of negative facial expressions such as anger and sad. Our study provides evidence for a possible influence of the COMT polymorphism on emotion recognition abilities in healthy subjects. Additional research is needed to further define the neurocognitive phenotypes associated with COMT polymorphisms.     

When in vitro fertilization fails: a prospective view.

New reproductive technologies such as in vitro fertilization (IVF) offer much hope to infertile couples, yet the odds for success are not high. In this study we examine the experiences of a cohort of women undergoing IVF or a related technology at three points in time: before technological intervention, approximately one month after the first failed cycle, and six months later. We consider the women's expectations and experiences and discuss implications of the findings for social work practice.     

Enhanced in vivo cytotoxicity of recombinant human tumor necrosis factor with etoposide in human renal cell carcinoma

Summary The combination of tumor necrosis factor (TNF) and etoposide (ETP) was evaluated for potential cytotoxic efficacy against a human renal cell carcinoma xenograft using an in vivo assay employing an athymic mouse host with tumor implanted a the subrenal capsule site. Both antitumor efficacy (relative survival or RTS) and toxicity (weight loss) of TNF and ETP alone and in combination were evaluated. While TNF and ETP alone were mildly inhibitory (RTS 90% and 71%, respectively), the combination caused marked tumor inhibition (45% of controls). Host toxicity encountered with the combination did not exceed the toxicity associated with ETP alone, suggesting that the therapeutic index may have been augmented. It is concluded that enhanced antitumor activity without substantial augmentation of toxicity is observed with this combination, providing a rationale for further evaluation of tumor necrosis factor-based regimens for the treatment of advanced renal carcinoma.Supported by a Merit Review grant, VA Medical Research Service, Durham, NC 27710, USA