Biomedical subjects
Publications and source records attributed to John M Russell.
Metastases to the penis are a rare event with most arising from pelvic organs, but occasionally the kidneys. Furthermore, very few cases exist where primary rectal carcinoma metastasising to the penis has been reported. We report on such a case and discuss the general management of penile metastases.
Androgen withdrawal causes the regression of prostate cancer and is used in therapy, but the role of androgens in the development of prostate cancer is uncertain. We present a case of prostate cancer diagnosed in a man who had been clinically androgen deficient for some years. This case and reviewed literature suggest that while early androgen exposure may be important in the prostatic carcinogenesis, late onset androgen deficiency is not protective. Thus, hypogonadal men considering androgen replacement therapy need to be adequately counseled, screened for prostate cancer and followed closely during treatment.
A hallmark of human cytomegalovirus (HCMV) infection is the characteristic enlargement of the host cells (i.e., cytomegaly). Because iron (Fe) is required for cell growth and Fe chelators inhibit viral replication, we investigated the effects of HCMV infection on Fe homeostasis in MRC-5 fibroblasts. Using the metallosensitive fluorophore calcein and the Fe chelator salicylaldehyde isonicotinoyl hydrazone (SIH), the labile iron pool (LIP) in mock-infected cells was determined to be 1.04 +/- 0.05 microM. Twenty-four hours postinfection (hpi), the size of the LIP had nearly doubled. Because cytomegaly occurs between 24 and 96 hpi, access to this larger LIP could be expected to facilitate enlargement to approximately 375% of the initial cell size. The ability of Fe chelation by 100 microM SIH to limit enlargement to approximately 180% confirms that the LIP plays a major role in cytomegaly. The effect of SIH chelation on the mitochondrial membrane potential (DeltaPsi(M)) and morphology was studied using the mitochondrial voltage-sensitive dye JC-1. The mitochondria in mock-infected cells were heterogeneous with a broad distribution of DeltaPsi(M) and were threadlike. In contrast, the mitochondria of HCMV-infected cells had a more depolarized DeltaPsi(M) distributed over a narrow range and were grainlike in appearance. However, the HCMV-induced alteration in DeltaPsi(M) was not affected by SIH chelation. We conclude that the development of cytomegaly is inhibited by Fe chelation and may be facilitated by an HCMV-induced increase in the LIP.
We (41) previously reported that Na-K-Cl-cotransporter (NKCC) function and microsomal protein expression are both dramatically reduced late in human cytomegalovirus (HCMV) infection of a human fibroblast cell line (MRC-5). We now report DNA microarray data showing that no significant HCMV-dependent NKCC gene repression can be detected 30 h postexposure (PE) to the virus. Consequently, we used plasma membrane biotinylation and subsequent subcellular fractionation in combination with semiquantitative immunoblotting and confocal microscopy to investigate the possibility that intracellular redistribution of the NKCC protein after HCMV infection could be a cause of the HCMV-induced loss of NKCC ion transport function. Our results show that the lifetime of plasmalemmal NKCC protein in quiescent, uninfected MRC-5 cells is approximately 48 h, and <20% of the total expressed NKCC protein are in the plasma membrane. The remainder (approximately 80%) was detected as diffusely distributed, small punctate structures in the cytoplasm. Following HCMV infection: 1) NKCC protein expression in the plasmalemma was sharply reduced (approximately 75%) within 24 h PE and thereafter continued to slowly decrease; 2) total cellular NKCC protein content remained unchanged or slightly increased during the course of the viral infection; and 3) HCMV infection caused NKCC protein to accumulate in the perinuclear region late in the HCMV infection (72 h PE). Thus our results imply that, in the process of productive HCMV infection, NKCC protein continues to be synthesized, but, instead of being delivered to the plasma membrane, it is clustered in a large, detergent-soluble perinuclear structure.
BACKGROUND: Ureteric stents have been used in urological practice for over 25 years and in many cases have become almost routine. The purpose of the present review is to highlight the uses, complications and risk management issues associated with their use. METHODS: An extensive literature review was conducted and knowledge from past experience was accessed to give a summary of past and current ureteric stent use in urology. RESULTS: Broadly, there are stone and non-stone indications for stenting. Complications may range from the commonly experienced 'stent syndrome' to the medico-legal dilemma of the forgotten stent. Risk management must be applied to all uses of stenting to minimize complications and achieve best practice. CONCLUSION: Although almost routine in many areas of urological practice, the complications and implications for risk management of ureteric stenting cannot be ignored.
Suprapubic catheters have gained wide acceptance in urology. Although many regard their insertion a simple procedure, morbidity is significant and is probably underreported. We describe a percutaneous technique using intraoperative ultrasonography combined with flexible cystoscopy to ensure safe insertion, minimizing the risk to adjacent viscera.