Acute stroke care in an Irish general hospital.

A majority of in-patients with acute stroke in Ireland are cared for by general physicians. We studied the process of care and outcomes of stroke patients admitted to an acute general hospital in a rural setting. Ninety-five patients (55 males and 40 females) were admitted over 36 weeks. A majority of patients had a CT brain scan (97%) and were assessed by the multidisciplinary team (59-70%). The mean length of stay was 16.6 days. In patient mortality was 18.9%. The commonest discharge destination was to the Medical Rehabilitation Unit (44%). A high prevalence of cardiovascular risk factors was identified indicating significant potential for secondary prevention.

A high-throughput assay for mitochondrial membrane potential in permeabilized yeast cells.

A fluorometric assay for mitochondrial membrane potential in permeabilized yeast cells has been developed. This method involves permeabilizing the plasma membrane and measuring the distribution of a mitochondrial membrane potential sensitive probe 3,3'-dipropylthiadicarbocyanine iodide (DiSC(3)(5); DiSC(3)). In permeabilized cells, DiSC(3) fluorescence decreased when introduced into energized mitochondria and increased three- to sixfold when the mitochondrial membrane potential was dissipated by the chemical uncoupler carbonylcyanide m-chlorophenyl hydrazone. Plasma membrane potential was abolished by permeabilization, as shown by a lack of polarization of the plasma membrane induced by K(+) and glucose. Uncoupling protein 1 (UCP1), a mitochondrial H(+) transporter, was used as a model for method validation. The fluorescence intensity responded vigorously to specific modulators in UCP1-expressing cells. This method has been adapted as a high-throughput assay to screen for modulators of mitochondrial membrane potential.

p53 expression in correlation to clinical outcome in patients with renal cell carcinoma.

OBJECTIVE: The aim of this study was to evaluate the role of p53 as prognostic factor in renal cell carcinoma (RCC) and its relation to clinicopathological factors. MATERIAL AND METHODS: The nuclear accumulation of p53 protein was determined by immunohistochemical analysis in RCC specimens from 90 patients and was correlated with clinical stage, grade, DNA ploidy, S-phase fraction and cancer-specific survival. RESULTS: p53 overexpression was observed in 17 of 90 (19%) tumours. There was a significant correlation to stage (p = 0.016) and grade (p = 0.020) but not to DNA ploidy or S-phase. Patients with high p53 immunoreactivity had shorter cancer-specific survival (p = 0.003) than those with normal p53 protein expression. This difference was found in papillary and chromophobe tumour types (p < 0.0001) but not in conventional RCC. CONCLUSIONS: In patients with RCC, significant correlations between p53 protein expression and tumour stage, grade and survival time were observed. For patients with chromophobe and papillary tumour types, but not in conventional RCC, p53 immunoreactivity gave prognostic information, suggesting that the prognostic differences in p53 immunoreactivity might be due to disparate genetic abnormalities in the different RCC types.

Forskolin increases the expression of the pancreatic tumor antigen, Nd2, and uptake of Nd2 antibody.

Nd2 antibody recognizes an antigen that is tumor specific in pancreas. It has been used successfully in clinical radioimmunodetection studies to identify exocrine pancreatic tumors. In the present study we show that the uptake of radiolabeled Nd2 antibody by SW1990 pancreatic carcinoma cells was increased by the adenyl cyclase activator, forskolin. Dibutyryl cyclic AMP and forskolin were both effective in increasing the level of Nd2 antigen in SW1990 cells. Immunoprecipitation studies showed that the Nd2 epitope is associated with MUC1 mucin. Forskolin increased Nd2/MUC1 antigen in both a membrane fraction and a high buoyant density mucin-like fraction. Nd2 immunoreactivity was reduced by treatment of mucins with proteases and beta-mercaptoethanol. Immunohistochemical studies showed that periodate catalyzed beta-elimination greatly reduced Nd2 immunoreactivity. These results suggest that the Nd2 epitope is unusual in having characteristics of both a peptide and a carbohydrate, protease and conformation sensitivities and involvement of O-linked oligosaccharides. Nd2 antibody does not react with several known pancreatic cancer antigens. In summary, activation of the cyclic AMP pathway increased cellular uptake of Nd2 antibody and the cellular expression of the tumor-specific, mucin-associated Nd2 antigen. These results suggest a means of improving the effectiveness of monoclonal antibodies in targeting tumor antigens for the diagnosis and treatment of malignancy.

Forskolin and phorbol ester have opposite effects on the expression of mucin-associated sialyl-Lewis(a) in pancreatic cancer cells.

The carbohydrate antigen sialyl-Lewis(a) is important to pancreatic tumour biology because the circulating antigen is used in serological tests for malignancy and because cell surface antigen is involved in tumour cell binding to the endothelial adhesion molecule, E-selectin, in extravasation. In this study, we examined the effects of the adenylyl cyclase activator, forskolin, and the diacylglycerol analogue, phorbol 12-myristate 13-acetate (PMA), on the expression and release of sialyl-Lewis(a) in human pancreatic cancer cells. Increases in the release of sialyl-Lewis(a) from SW1990 cells produced by forskolin and PMA were associated with increases in the activities of protein kinases A and C, respectively, and could be blocked by inhibitors specific for these enzymes. Immunoprecipitation experiments showed that sialyl-Lewis(a) was associated with MUC1 mucin. Forskolin also increased the cellular content of antigen and MUC1 mRNA. Actinomycin D and a protein kinase A inhibitor, H8, blocked these effects. In contrast, PMA reduced cellular antigen and MUC1 mRNA levels, although it produced a temporary increase in release of the antigen. The effects of PMA were blocked by the protein kinase C inhibitor, H7. PMA also reduced cell binding to the adhesion molecule E-selectin. In summary, PKA and PKC alter cell MUC1-associated sialyl-Lewis(a) in opposite directions. These changes may have clinical utility in the diagnosis of pancreatic cancer and the prevention of metastases.

Phorbol ester reduces phosphorylation of epidermal growth factor receptor in pancreatic cancer cells by activation of a tyrosine phosphatase.

In this study we report that phorbol 12-myristate 13-acetate (PMA) transiently reduced the level of EGF receptor tyrosine phosphorylation in three pancreatic cancer cell lines (HPAC, SW1990, and UCVA-1) in response to EGF. The effect was maximal at 40-90 min. Pretreatment with the protein kinase C inhibitor GF 109203X reduced the PMA effect. Flow cytometry experiments showed that PMA produced only a slight reduction in the surface expression of EGF-R. The phosphotyrosine phosphatase inhibitor bpV(phen) returned phosphorylation to almost control levels. Moreover, homogenates of PMA treated pancreatic cells reduced the phosphorylation of activated receptor that was immunoprecipitated from A431 epidermoid cells. A combination of orthovanadate and NaF or bpV(phen) inhibited the effect of the homogenates. These results suggest that PMA activates a phosphotyrosine phosphatase activity that reduces the steady-state level of tyrosine phosphorylation of the receptor that is induced by EGF.

Accuracy of clinical staging in non-seminomatous testicular cancer--a single centre experience of retroperitoneal lymph node dissection.

The management of low stage non-seminomatous testicular cancer remains a controversial issue. Programs of surveillance or primary retroperitoneal lymph node dissection (RPLND) after orchiectomy show equally good survival rates. Current focus is therefore on reduction of toxicity or side effects of the treatment while maintaining maximal prognostic safety. The clinician's decision of therapy is based on clinical staging methods including computerized tomography, pulmonary x-rays and serum tumour marker levels. In this study, the accuracy of clinical staging was compared with histopathology in 64 patients with clinical stages (CS) I and IIa, operated upon with RPLND between 1980 and 1992. Lymph node metastases were histopathologically verified in 37% of CS I and in 47% of CS IIa tumours. Thus, the clinical staging was inaccurate in 37% in CS I and in 53% in CS IIa patients. No clear relationship was shown between the risk factors: vascular invasion and/or tumour marker levels and metastatic spread. The specificity of clinical staging in non seminomatous testicular cancer was low. RPLND, on the other hand, is a reliable method for assessment of metastatic spread and will minimise unnecessary use of chemotherapy. Modern techniques for lymphadenectomy have a very low rate of post-operative morbidity. Development of better non-invasive imaging techniques for detection of lymph node metastases is hoped for, in order to improve the information on tumour spread and make it possible to individualize therapy. Thus, unnecessary therapy and following side-effects can be avoided, improving the patient's quality of life during and after treatment.

Vein invasion in renal cell carcinoma: impact on metastatic behavior and survival.

PURPOSE: The development of a thrombus extending into the veins is well recognized in renal cell carcinoma. We investigated the hypothesis that vein invasion alone has no adverse impact on survival but is a highly negative factor in other tumors. MATERIALS AND METHODS: In 200 consecutive patients invasion of the renal vein and vena cava was evaluated and compared with the clinical course. RESULTS: A total of 26 patients had vena caval and 47 had renal vein invasion. Patients with venous invasion had a significantly shorter survival but no survival difference was demonstrated based on the level of involvement. CONCLUSIONS: Our study indicates that vein invasion itself seems to be an important prognostic factor in renal cell carcinoma.