Biomedical subjects
Publications and source records attributed to Benjamin Davies.
To our knowledge, we provide an initial description of an adult patient undergoing a retroperitoneal partial nephrectomy in the prone position. The prone position was chosen because of the posteromedial location of the patient's right kidney lesion. We describe our surgical methods and the potential pitfalls to this approach.
Most retroperitoneal tumors such as renal cell carcinoma have been associated with tumor thrombus extending into the renal vein, inferior vena cava (IVC), and heart. The retroperitoneal metastatic potential of testicular tumors is well known. We report here the first instance of a cardiac murmur prompting diagnosis of metastatic testicular neoplasia in an 18-year-old patient. Chemotherapy was delayed and after successful surgical resection of the ventricular mass, the patient recovered uneventfully. This case underscores the need to pursue abnormal cardiac exams in newly diagnosed testicular cancer patients.
OBJECTIVES: To evaluate three urine markers, BTA stat, cytology, and urinary survivin levels, in the spinal cord injury (SCI) population. The incidence of bladder cancer in patients with SCI is up to 20 times greater than in the general population. However, bladder cancer biomarkers have not been assessed in this population. METHODS: Between April 1999 and April 2004, 457 patients with SCI enrolled at the HealthSouth Harmarville Rehabilitation Spinal Cord Clinic donated their urine to our SCI urine repository. BTA stat tests and the survivin assay were performed according to published standards. Cytology specimens were sent to our cytopathology laboratory for analysis. RESULTS: A total of 1075 urine specimens from 457 patients were analyzed. Of the 1073 BTA stat tests, 119 showed positive reactions and 954 were negative. In the survivin assays, 47 samples had a score of 1, 38 a score of 2, and 9 a score of 3. No cytology specimens were noted to have malignant cells. During the past 5 years, 3 patients were diagnosed with bladder cancer by cystoscopy and treated for superficial disease. For these patients, none of these three tests (BTA stat, survivin assay, and cytology) was positive before the diagnosis of bladder cancer. CONCLUSIONS: The BTA stat, survivin assay, and urine cytology were unable to predict bladder cancer cases in our cohort of patients with SCI. Cystoscopy, therefore, remains the gold standard for bladder cancer surveillance in patients with SCI.
PURPOSE: We determined if urinary survivin is influenced by the prostate and analyzed survivin levels in a healthy control population. MATERIALS AND METHODS: This was a blinded, retrospective analysis of frozen urine samples. Three groups were designated. Group 1 patients were diagnosed with prostate cancer and samples were collected immediately prior to radical retropubic prostatectomy. Group 2 patients had already undergone radical retropubic prostatectomy at least 3 months prior to providing a urine sample. Group 3 comprised healthy controls. Groups 1 and 2 patients were recruited at an institutional practice. Group 3 patients were recruited from the local community. RESULTS: The frequency of high survivin scores was much lower in patients who did not have a prostate (p < 0.0002). The survivin score was 2 in 35% and 44% of the patients in groups 1 and 3, respectively, while only 9% of those in group 2 had a survivin score of 2 (p < 0.0002). Of healthy controls 50% had a false-positive survivin score. Urinary survivin predicted prostate cancer poorly with 52% sensitivity and 50% specificity, and it did not predict any biological features of prostate cancer. CONCLUSIONS: Urinary survivin markedly decreases after prostatectomy. There is a 50% false-positive rate when using urinary survivin in controls. These 2 features make urinary survivin a poor bladder cancer biomarker.
Serotonergic neurons play a major role in the modulation of emotion and behaviour. Especially knockout studies have revealed a role for the serotonin(1A) (5-HT(1A)) receptor in anxiety related behaviour. Mutant animals exhibit enhanced anxiety-like responses, possibly resulting from impaired autoinhibitory control of midbrain serotonergic neurons. To further elucidate the role of the 5-HT(1A) receptors in affective behaviour, a complementary approach has been used and transgenic mice overexpressing this receptor subtype have been generated. The expression of the active 5-HT(1A) receptor protein as indicated by autoradiography was transiently increased during early postnatal development (P1.5) as compared to wild-type mice. Within the next 2 weeks, the increase in receptor binding vanished and was also not apparent in adult animals indicating adaptive changes in the regulation of 5-HT(1A) receptor expression. Although no evidence for increased receptor binding in the brains of adult homozygous mice was found by autoradiography, typical phenotypic changes indicative of 5-HT(1A) receptor overactivity were apparent. Transgenic mice revealed a reduced molar ratio of 5-hydroxyindoleacetic acid to serotonin in several brain areas and elevated serotonin values in the hippocampus and striatum. Moreover, anxiety-like behaviour was decreased in male and female transgenic mice and body temperature was lowered in male transgenic mice in comparison with heterozygous and wild-type mice. These findings further underline the pivotal role of 5-HT(1A) receptors in the homeostasis of anxiety-like behaviour and the crucial importance of stimulation of the 5-HT(1A) receptor during the early postnatal development for normal anxiety-like behaviour throughout life.
The expression level of the 5-HT(1A) receptor gene (htr1a) in the central nervous system (CNS) is implicated in the aetiology and treatment of anxiety disorders and depression. Previous studies of the murine htr1a have revealed that its proximal promoter is GC rich and TATA-less. Several functional transcription factor binding sites, including MAZ and SP1 recognition sequences, have been identified. To further analyse the promoter of this receptor gene, additional upstream sequence information extending to -5.5 kb of the murine htr1a was generated and promoter fragments extending to -20 kb were analysed for activity in cell culture and transgenic animals. Promoter fragments greater than 4.5 kb in length were active in 5-HT(1A) receptor mRNA positive cells and inactive in 5-HT(1A) receptor mRNA negative cells. Smaller fragments were not able to confer this specificity. In agreement, using additive transgenesis to drive LacZ expression in vivo, CNS specific reporter gene expression was found with these longer constructs. Transgene expression in the 4.5- and 20-kb mouse lines resembled the endogenous htr1a expression pattern, whereas the 5.5-kb mouse lines surprisingly revealed strongly reduced expression. None of the three constructs was prone to confer ectopic expression, however, variation of expression between the transgenic lines was observed. Using colocalization studies we analysed the degree of concurrence of transgenic and endogenous htr1a expression brought about by these three different constructs. The highest degrees of colocalization were observed in mice harbouring the 20-kb construct, suggesting a large promoter fragment is required to faithfully direct transgene expression in a 5-HT(1A) receptor like pattern.