Conservative surgical therapy for penile and urethral carcinoma

OBJECTIVES: Invasive penile and urethral tumors are traditionally treated with aggressive excision that requires involved organ and adjacent organ sacrifice. An alternative approach seeks to completely excise the tumor with adequate margins while preserving form and function of the organ. We present 6 patients who underwent such organ-sparing surgery. METHODS: Six selected cases (4 penile and 2 urethral) are presented with operative photographs and pertinent data. RESULTS: Three distal tumors of the penis were treated with excision limited to the glans with histopathologic findings of verrucous carcinoma, melanoma, and angiosarcoma. One patient with squamous cell carcinoma of the distal shaft refused partial penectomy and underwent a local wedge resection. A patient with locally advanced bulbourethral transitional cell carcinoma (TCC) refused cystourethrectomy and underwent an anterior urethrectomy and perineal urethrostomy. A 48-year-old woman with an adenocarcinoma contained in a very distal urethral diverticulum underwent simple diverticulectomy and excision of distal urethra. Postoperative voiding and sexual function were well preserved. Follow-up was 12 to 48 months. The patient with angiosarcoma died of lung metastases at 48 months with no local disease, and the patient with bulbourethral TCC developed pelvic disease at 12 months with no local recurrence and died of metastases at 25 months. CONCLUSIONS: Organ-sparing surgery is appropriate in selected patients on the basis of stage and location, high risk of distant failure, and patient disposition. Close follow-up is necessary. Comanagement with reconstructive and oncologic specialists optimizes results and outcomes.     

Poverty and disrepair: Challenging the myth of ignorance in private sector housing

As private home ownership grows in Europe, so do the problems of maintenance and repair for poorer owners. In England, it has been believed that one obstacle is the owners' apparent satisfaction with poor conditions. This paper deconstructs the questions in the English House Condition Survey 1981 on which that assumption has been based. By reference to other EHCSs and to a research methodology offering a more differentiated approach to establishing residents' views, it suggests that the problem is not ignorance at all. A more subtle understanding of the validity of housing satisfaction questionnaires is needed to develop effective policies of urban renewal.     

Significance of lymph node sampling in epithelial carcinoma of the ovary

Dendritic cells (DC) are a subset of leukocytes whose major function is antigen presentation. We investigated the phenotype and function of enriched (95-98.5%) rat DC. We show that both spleen and thymus DC express the natural killer cell receptor protein 1 (NKR-P1) as a disulfide linked homodimer of 60 kD. Freshly isolated DC express a low level of NKR-P1, which is strongly upregulated after overnight culture. Spleen, but not thymus DC, were able to kill the NK-sensitive YAC-1 cell line in vitro, and since this killing was Ca2+ dependent, a Fas ligand-Fas interaction was probably not involved. Besides their potent antigen-presenting function, DC can thus be cytotoxic for some tumor targets.     

Coherent Optical Recognition and Counting of Reticulated Red Blood Cells

A coherent optical data-processing system for identifying and counting blood cells has been developed. Optical Weiner-Kolmogorov (minimum mean-square error) linear filtering is employed to estimate the density per unit area of a given cell type present in a sample blood smear. The Weiner filter is designed to recognize the characteristics of an ensemble of cells of a type rather than specific individual cells. In this way the system is made insensitive to minor variations in shape, size, or orientation of the cells. A Poisson shot-noise model for blood cells as a spatial random process is employed to calculate the far-field scattering from the cells. Results of experiments in which the percentage of reticulated (immature) red cells present in a smear has been determined are presented. The identification and counting accuracies compare favorably with those obtained by laboratory technicians with a microscope. The potential time saving of instantaneous estimation for the entire smear is significant.     

Prediction of residual retroperitoneal mass histology after chemotherapy for metastatic nonseminomatous germ cell tumor: multivariate analysis of individual patient data from six study groups

PURPOSE: To develop a statistical model that predicts the histology (necrosis, mature teratoma, or cancer) after chemotherapy for metastatic nonseminomatous germ cell tumor (NSGCT). PATIENTS AND METHODS: An international data set was collected comprising individual patient data from six study groups. Logistic regression analysis was used to estimate the probability of necrosis and the ratio of cancer and mature teratoma. RESULTS: Of 556 patients, 250 (45%) had necrosis at resection, 236 (42%) had mature teratoma, and 70 (13%) had cancer. Predictors of necrosis were the absence of teratoma elements in the primary tumor, prechemotherapy normal alfa-fetoprotein (AFP), normal human chorionic gonadotropin (HCG), and elevated lactate dehydrogenase (LDH) levels, a small prechemotherapy or postchemotherapy mass, and a large shrinkage of the mass during chemotherapy. Multivariate combination of predictors yielded reliable models (goodness-of-fit tests, P > .20), which discriminated necrosis well from other histologies (area under the receiver operating characteristic (ROC) curve, .84), but which discriminated cancer only reasonably from mature teratoma (area, .66). Internal and external validation confirmed these findings. CONCLUSION: The validated models estimate with high accuracy the histology at resection, especially necrosis, based on well-known and readily available predictors. The predicted probabilities may help to choose between immediate resection of a residual mass or follow-up, taking into account the expected benefits and risks of resection, feasibility of frequent follow-up, the financial costs, and the patient's individual preferences.     

Properties and functions of the thiamin diphosphate dependent enzyme transketolase

This review highlights recent research on the properties and functions of the enzyme transketolase, which requires thiamin diphosphate and a divalent metal ion for its activity. The transketolase-catalysed reaction is part of the pentose phosphate pathway, where transketolase appears to control the non-oxidative branch of this pathway, although the overall flux of labelled substrates remains controversial. Yeast transketolase is one of several thiamin diphosphate dependent enzymes whose three-dimensional structures have been determined. Together with mutational analysis these structural data have led to detailed understanding of thiamin diphosphate catalysed reactions. In the homodimer transketolase the two catalytic sites, where dihydroxyethyl groups are transferred from ketose donors to aldose acceptors, are formed at the interface between the two subunits, where the thiazole and pyrimidine rings of thiamin diphosphate are bound. Transketolase is ubiquitous and more than 30 full-length sequences are known. The encoded protein sequences contain two motifs of high homology; one common to all thiamin diphosphate-dependent enzymes and the other a unique transketolase motif. All characterised transketolases have similar kinetic and physical properties, but the mammalian enzymes are more selective in substrate utilisation than the nonmammalian representatives. Since products of the transketolase-catalysed reaction serve as precursors for a number of synthetic compounds this enzyme has been exploited for industrial applications. Putative mutant forms of transketolase, once believed to predispose to disease, have not stood up to scrutiny. However, a modification of transketolase is a marker for Alzheimer's disease, and transketolase activity in erythrocytes is a measure of thiamin nutrition. The cornea contains a particularly high transketolase concentration, consistent with the proposal that pentose phosphate pathway activity has a role in the removal of light-generated radicals.     

Histamine release from rat mast cells induced by the metabolic activation of drugs of abuse into free radicals

Techniques such as positron-emission tomography, single-photon-emission computed tomography, functional magnetic-resonance imaging and magnetoencephalography permit the observation of biological processes in the brain in a noninvasive manner. They have yielded new insights into the biological interrelations of sensory, motor and cognitive functions, as well as into brain diseases. Combined use of these techniques may provide more information than just the sum of its constituents, and this may narrow the gap between the biological data provided by these techniques and the mental models described by clinicians, mathematicians, psychologists and philosophers.     

Chemotherapy in advanced ovarian cancer: four systematic meta-analyses of individual patient data from 37 randomized trials. Advanced Ovarian Cancer Trialists' Group

The purpose of this systematic study was to provide an up to date and reliable quantitative summary of the relative benefits of various types of chemotherapy (non-platinum vs platinum, single-agent vs combination and carboplatin vs cisplatin) in the treatment of advanced ovarian cancer. Also, to investigate whether well-defined patient subgroups benefit more or less from cisplatin- or carboplatin-based therapy. Meta-analyses were based on updated individual patient data from all available randomized controlled trials (published and unpublished), including 37 trials, 5667 patients and 4664 deaths. The results suggest that platinum-based chemotherapy is better than non-platinum therapy, show a trend in favour of platinum combinations over single-agent platinum, and suggest that cisplatin and carboplatin are equally effective. There is no good evidence that cisplatin is more or less effective than carboplatin in any particular subgroup of patients.