Prostate cancer: measuring PSA.

Population screening with prostate-specific antigen (PSA) for detection of prostate cancer is a topic associated with ongoing dissent and confusion within the oncology and wider medical community. The PSA blood test has been used in various stages of prostate cancer management, including screening and the assessment of future risk of prostate cancer development, detection of recurrent disease after local therapy and in the management of advanced disease. However, PSA-based decision-making in prostate cancer has significant shortcomings. This review will summarise the evidence and current recommendations for the use of PSA in detection and management of prostate cancer.

Does Increasing Packing Density Using Larger Caliber Coils Improve Angiographic Results of Embolization of Intracranial Aneurysms at 1 Year: A Randomized Trial.

BACKGROUND AND PURPOSE: The impact of increased aneurysm packing density on angiographic outcomes has not been studied in a randomized trial. We sought to determine the potential for larger caliber coils to achieve higher packing densities and to improve the angiographic results of embolization of intracranial aneurysms at 1 year. MATERIALS AND METHODS: Does Embolization with Larger Coils Lead to Better Treatment of Aneurysms (DELTA) was an investigator-initiated multicenter prospective, parallel, randomized, controlled clinical trial. Patients had 4- to 12-mm unruptured aneurysms. Treatment allocation to either 15- (experimental) or 10-caliber coils (control group) was randomized 1:1 using a Web-based platform. The primary efficacy outcome was a major recurrence or a residual aneurysm at follow-up angiography at 12 ± 2 months adjudicated by an independent core lab blinded to the treatment allocation. Secondary outcomes included indices of treatment success and standard safety outcomes. Recruitment of 564 patients was judged necessary to show a decrease in poor outcomes from 33% to 20% with 15-caliber coils. RESULTS: Funding was interrupted and the trial was stopped after 210 patients were recruited between November 2013 and June 2017. On an intent-to-treat analysis, the primary outcome was reached in 37 patients allocated to 15-caliber coils and 36 patients allocated to 10-caliber coils (OR = 0.931; 95% CI, 0.528-1.644; P = .885). Safety and other clinical outcomes were similar. The 15-caliber coil group had a higher mean packing density (37.0% versus 26.9%, P = .0001). Packing density had no effect on the primary outcome when adjusted for initial angiographic results (OR = 1.001; 95% CI, 0.981-1.022; P = .879). CONCLUSIONS: Coiling of aneurysms randomized to 15-caliber coils achieved higher packing densities compared with 10-caliber coils, but this had no impact on the angiographic outcomes at 1 year, which were primarily driven by aneurysm size and initial angiographic results.

Rapid intracranial clot removal with a new device: the alligator retriever.

BACKGROUND AND PURPOSE: Despite availability of an approved drug to treat acute cerebral ischemia, most patients with stroke do not realize a good outcome. A method that would rapidly increase or restore cerebral perfusion before irreversible cell death should improve patient outcomes. MATERIALS AND METHODS: We recently had the opportunity to treat 6 middle-aged-to-elderly patients who presented with signs and symptoms of acute cerebral ischemia, by mechanically removing their (predominantly) middle cerebral artery clots by using a new retrieval device that had been previously approved by the US Food and Drug Administration for intravascular retrieval of foreign bodies. During a 2-month period, the 6 patients were treated in 5 separate institutions. No patient had an unsuccessful attempt at clot removal. The cases were collected by personal communication with each operator. RESULTS: In all instances, use of the device resulted in rapid clot removal. Each patient had a large improvement in National Institutes of Health Stroke Scale score. Two of the 6 patients had experienced failure of another clot retrieval device, and 3 patients required no systemic thrombolytics, reducing the likelihood of one of the most feared complications of stroke therapy, intracranial hemorrhage. SUMMARY: We believe that use of this device may result in improved outcomes for patients with acute ischemic stroke. In our limited experience, it provided a rapid, safe, and effective means for achieving revascularization.

Self-expanding stents for recanalization of acute cerebrovascular occlusions.

BACKGROUND AND PURPOSE: Stent-assisted revascularization increases prevailing recanalization rates ( congruent with 50%-69%) for vessel occlusions recalcitrant to thrombolytics. Although balloon-mounted coronary stents can displace thrombus (via angioplasty) and retain clot along vessel walls, intracranial self-expanding stents are more flexible and exert less radial outward force during deployment, increasing deliverability and safety. To understand the effectiveness of self-expanding stents for recanalization of acute cerebrovascular occlusions, we retrospectively reviewed our preliminary experience with these stents. MATERIALS AND METHODS: Eighteen patients (19 lesions) presenting with a clinical diagnosis of acute stroke underwent catheter-based angiography documenting focal occlusion of an intracranial artery. A self-expanding stent was delivered to the occlusion and deployed. Stent placement was the initial mechanical maneuver in 6 cases; others involved a combination of pharmacologic and/or mechanical maneuvers prestenting. GP IIb/IIIa inhibitors were administered in 10 cases intraprocedurally or immediately postprocedurally to avoid acute in-stent thrombosis. RESULTS: Stent deployment at the target occlusion (technical success) was achieved in all cases. Thrombolysis in Cerebral Ischemia (TICI)/Thrombolysis in Myocardial Ischemia (TIMI) 2/3 recanalization (angiographic success) was achieved in 15 of 19 lesions (79%). All single-vessel lesions (n=8) were recanalized, but only 7 of 11 combination internal carotid artery and middle cerebral artery lesions were recanalized. No intraprocedural complications occurred. Seven in-hospital deaths occurred: stroke progression, 4; intracranial hemorrhage, 2; respiratory failure, 1. Seven patients had >or=4-point National Institutes of Health Stroke Scale improvement within 24 hours after the procedure, 6 had modified Rankin Score (mRS)

Lutetium-177-labelled anti-prostate-specific membrane antigen antibody and ligands for the treatment of metastatic castrate-resistant prostate cancer: a systematic review and meta-analysis.

BACKGROUND: Promising therapeutic results of the prostate-specific membrane antigen (PSMA) ligand have been shown when labelling with lutetium-177 (177Lu). We performed a systematic review and meta-analysis to assess the therapeutic response of 177Lu-PSMA in the treatment of metastatic castration-resistant prostate cancer (mCRPC). METHODS: A systematic review was conducted using electronic databases up to December 2016. Two reviewers independently extracted data and assessed methodological quality. The main outcome of interest was antitumour biochemical response of 177Lu-PSMA, analysing two measures: 'any PSA decline' and '>50% decline' from baseline. A random-effects meta-analysis was used to calculate the pooled proportion across studies. The I2 statistic was calculated in each case to investigate the extent of heterogeneity across the studies. A sensitivity analysis was conducted removing two studies, which were presented as abstracts and proportions were summarised by chemical type (177Lu-J591/DKZ/I&T). All analyses were conducted using Stata v14. RESULTS: A total of 10 studies were included in the analysis giving a total sample size of 369, 220 (of 334 analysable) experienced any PSA decline. The pooled proportion of patients with any PSA decline was 68% (95% confidence interval (CI): 61-74). The I2 statistic was 39.1% (P=0.11) suggesting minor heterogeneity between results. The pooled proportion of patients with >50% PSA decline was 37% (95% CI: 22-52). The I2 statistic was 91.0% (P<0.001) suggesting substantial heterogeneity between results. On subgroup analysis, a higher proportion of patients in the 177Lu-DKZ/I&T subgroup had a PSA decline >50%, however, it can be seen that the 177Lu-DKZ/I&T subgroup had a substantial amount of heterogeneity across studies. CONCLUSIONS: This review suggests promising early results for the treatment of mCRPC, especially from patients treated with the more recently developed radioligands. Overall, our meta-analysis showed that approximately two-thirds of patients had a biochemical response. Randomised-controlled trials would be necessary to verify its effectiveness against current systemic therapies and create an ideal treatment protocol.

Function of root border cells in plant health: pioneers in the rhizosphere.

Plants dedicate a large amount of energy to the regulated production of living cells programmed to separate from roots into the external environment. This unusual process may be worth the cost because it enables the plant to dictate which species will share its ecological niche. For example, border cells can rapidly attract and stimulate growth in some microorganisms and repel and inhibit the growth of others. Such specificity may provide a way to control the dynamics of adjacent microbial populations in the soil to foster beneficial associations and inhibit pathogenic invasion. Plant genes controlling the delivery of border cells and the expression of their unique properties provide tools to genetically engineer plants with altered border cell quality and quantity. Such variants are being used to test the hypothesis that the function of border cells is to protect plant health by controlling the ecology of the root system.

Differential Expression of Proteins and mRNAs from Border Cells and Root Tips of Pea.

Many plants release large numbers of metabolically active root border cells into the rhizosphere. We have proposed that border cells, cells produced by the root cap meristem that separate from the rest of the root upon reaching the periphery of the cap, are a singularly differentiated part of the root system that modulates the environment of the plant root by producing specific substances to be released into the rhizosphere. Proteins synthesized in border cells exhibit profiles that are very distinct from those of the root tip (root cap, root meristem, and adjacent cells). In vivo-labeling experiments demonstrate that 13% of the proteins that are abundant in preparations from border cells are undetectable in root tip preparations. Twenty-five percent of the proteins synthesized by border cells in a 1-h period are rapidly excreted into the incubation medium. Quantitative variation in levels of specific marker proteins, including glutamine synthetase, heat-shock protein 70, and isoflavone reductase, also occurs between border cells and cells in the root tip. mRNA differential-display assays demonstrate that these large qualitative and quantitative differences in protein expression are correlated with similarly distinct patterns of gene expression. These observations are consistent with the hypothesis that a major switch in gene expression accompanies differentiation into root border cells, as expected for cells with specialized functions in plant development.

Systematic review and meta-analysis on management of acute urinary retention.

BACKGROUND: Acute urinary retention (AUR) is a common urological emergency. In this article, we review the current literature and present a structured summary in management of AUR. METHODS: A systematic review was conducted using the keywords 'acute AND retention AND urin*' within the title in search engines including Medline, EMBASE and EBM Review. The obtained literature was manually reviewed by the primary author (PDY) and was further refined by confining the subject to management of AUR. Exclusion criteria included paediatric and female population studies, case reports, reviews, surveys, economical assessment and articles on AUR in prostate cancer and post-operative patients. RESULTS: Total of 54 articles met our inclusion and exclusion criteria. The trial without catheter (TWOC) post-immediate catheterisation is widely practiced although there remains a significant variability in terms of type and duration of catheterisation required, use of concurrent medical therapy or post-catheterisation management. Our systematic review and subsequent meta-analysis has shown superiority of α1-adrenergic receptor blockers over placebo in achieving successful voiding in patients with AUR. Suprapubic catheter (SPC) is an alternative to urethral catheterisation (indwelling catheter (IDC)) and may provide several advantages. Clean intermittent self-catheterisation may be a safe and useful option for patients with AUR until their definitive management. The overall long-term outcome of in-and-out catheterisation remains promising in selected patients. Surgery is an end point in patients with unsuccessful TWOC as well as in those with significant lower urinary tract symptoms post-successful TWOC. CONCLUSIONS: We recommend use of α1-adrenergic receptor blockers before TWOC and discourage emergency operative management. Use of SPC over IDC in AUR is debatable. Duration of catheterisation is controversial but <3 days is a safe option in avoiding catheterisation-related complications. Although TURP remains the current gold standard, there has been an emergence of newer operative management utilising laser techniques.

Primary structure of the mRNA encoding a 16.5-kDa ubiquitin-conjugating enzyme of Pisum sativum.

The complementary DNA (PsU BC4) representing an mRNA encoding an ubiquitin-conjugating enzyme (UBC) of Pisum sativum has been cloned. The coding region is 444 nucleotides (nt) in length and capable of specifying a 16.5-kDa protein of 148 amino acids (aa) with an isoelectric point of 7.95. The deduced aa sequence showed 97% identity with Arabidopsis thaliana AtUBC8-12 families and tomato ERT17, and 80% identity with yeast ScUBC4 and ScUBC5 and Drosophila melanogaster DmUBC4. The active site cysteine (Cys85) found in UBCs so far described is also conserved in the P. sativum sequence.

The normal and abnormal postnatal development of retinogeniculate projections in golden hamsters: an anterograde horseradish peroxidase tracing study.

In adult hamsters, the dorsal lateral geniculate nucleus (LGd), which lacks a noticeable pattern of cellular lamination, receives fibers predominantly from the contralateral eye except for a medial segment which receives fibers from the ipsilateral eye. Using the method of anterograde transport of horseradish peroxidase (HRP), it is shown in this study that the contralateral and ipsilateral retinogeniculate fibers innervate the LGd by day 0 with the development of the contralateral fibers slightly ahead of the ipsilateral ones. The entire contralateral LGd is filled with retinal fibers by day 1. The ipsilateral LGd is almost completely covered with retinal fibers on day 2 but with the fiber density much higher in the dorsal half of the nucleus. Thus, fibers from both eyes overlap with each other completely beginning on day 2 in the LGd. The segregation of these fibers becomes obvious on day 6 as indicated by a decrease in the density of ipsilateral fibers in the ventral portion of the LGd while the ipsilateral projection continues to concentrate in the dorsal half of the nucleus. A low density area in the dorsomedial part of the contralateral LGd is observed on day 7. By day 8, the segregation of the contralateral and ipsilateral projections has achieved an adult-like pattern. Thus, there seems to be two phases for the normal development of the retinogeniculate fibers. In the first phase, axons from both eyes grow in and occupy the entire LGd. In the second phase, those axons occupying inappropriate areas of the LGd are eliminated to form the adult pattern. The effect of unilateral eye removal at birth on the development of the retinogeniculate projection from the remaining eye was also studied with the anterograde HRP method. The ipsilateral fibers in the experimental animals are distributed in the lateral portion of the nucleus in the first two postnatal days. The entire LGd is not filled with ipsilateral fibers until day 4. From day 6 onwards, the ipsilateral fibers are more extensive than those of the normal animals. In addition to a dense projection to the dorsal two-thirds of the LGd, moderate amount of ipsilateral axons can be detected in the remaining ventral portion of the nucleus in day 6 and older experimental animals. The development of the contralateral retinal fibers in the experimental animals is similar to that of the normal from day 1 to day 6, i.e. the entire LGd is densely filled with crossed optic axons.(ABSTRACT TRUNCATED AT 400 WORDS)

An anterograde HRP study of the retinocollicular pathways in normal hamsters and hamsters with one eye enucleated at birth.

The present anterograde HRP study indicated that the uncrossed retinal projection to the superior colliculus in both normal hamsters and hamsters with one eye enucleated at birth was more extensive than previously reported. In addition, a small retinal projection to the contralateral inferior colliculus was also observed in all animals studied.

The postnatal development of retinocollicular projections in normal hamsters and in hamsters following neonatal monocular enucleation: a horseradish peroxidase tracing study.

The pattern of distribution of the retinal projections to the superior colliculus (SC) has been studied in developing normal hamsters and in hamsters following unilateral eye enucleation at birth, using the anterograde horseradish peroxidase (HRP) method. The results show that in normal hamsters the contralateral retinocollicular projection has already reached the caudal pole of the SC on the day of birth, and covered the entire SC by day 1. The ipsilateral retinocollicular projection is distributed only to the rostrolateral portion of the SC on day 0, but has covered the entire area of the SC on day 1. The innervation of the SC by the ipsilateral projection increases gradually until it reaches its maximum density on day 3 or day 4. Beginning on day 6, the density of the ipsilateral projection decreases markedly except in areas where there is a distinct clumping of retinal fibers. The normal adult pattern, which consists of dense clumps of ipsilateral retinal projections in the rostral half of the SC and a sparse ipsilateral retinal projection distributing in almost the entire extent of the SC, is established on day 10. In animals in which one eye was removed on the day of birth, the ipsilateral projection is observed in the rostral two-thirds of the SC on day 1, and innervates the entire extent of the colliculus on day 2. On day 3 or day 4, this projection is denser than that found in normal animals of the same age. The SC remains heavily innervated by ipsilateral fibers on and after day 6. The abnormal adult pattern, which consists of dense ipsilateral retinal projections in most parts of the SC, is observed on day 10. The anomalous ipsilateral retinocollicular projection which develops in eye-enucleated animals suggests that there is a competitive interaction between fibers from the two eyes during development which is critical in shaping the normal adult pattern of the ipsilateral retinocollicular projection. The early development of the contralateral projection is in advance of the ipsilateral projection, and removal of the contralateral fibers by eye enucleation at birth seems to result in a further delay in the development of the ipsilateral projection. This suggests that in the hamster the contralateral fibers may play a role in guiding the ipsilateral fibers to reach their target region.(ABSTRACT TRUNCATED AT 400 WORDS)

Arachnoid cysts of the cerebellopontine angle: diagnosis and surgery.

OBJECTIVE: The optimal surgical management of arachnoid cysts remains controversial. The cerebellopontine angle (CPA) is a rare location for arachnoid cysts, and only 28 cases of arachnoid cysts occurring in the CPA have been reported in the literature. We discuss the diagnosis, radiographic imaging, and surgical management of CPA arachnoid cysts. METHODS: Five patients (three male and two female patients) with a mean age of 5.6 years have been operated on at our institution since 1980. Magnetic resonance imaging allows for the accurate diagnosis of these arachnoid cysts, which can present with only discrete symptoms, such as headache or ataxia. All five arachnoid cysts compressed the cerebellum or brain stem. One patient had associated hydrocephalus. Three patients presented with refractory headaches associated with nausea and vomiting. The remaining two patients presented with cerebellar signs. No patient had an initial cranial neuropathy. RESULTS: All patients underwent a retrosigmoid suboccipital craniotomy and microsurgical resection and fenestration of the cyst walls. One patient underwent two procedures. A cystoperitoneal shunt was inserted at the first operation. After the shunting procedure, the patient's condition deteriorated; however, after the microsurgical resection and fenestration, his symptoms improved. With a mean 5.2-year follow-up, there has been no evidence of clinical or radiographic recurrence. CONCLUSION: Although CPA arachnoid cysts represent a small number of total arachnoid cysts, the CPA is the second most common location for arachnoid cysts to occur. CPA cysts are congenital lesions found in children who present with subtle signs or symptoms. The definitive treatment for these arachnoid cysts is a retrosigmoid suboccipital craniotomy and microsurgical resection and fenestration of the cyst walls.

Contemporary management of spinal osteomyelitis.

OBJECTIVE: We review the results of treatment of a series of patients with spinal osteomyelitis, to formulate a systematic and comprehensive approach to the management of this disease in light of recent technical and conceptual advances in imaging, spinal biomechanics, and internal fixation. METHODS: We retrospectively reviewed the records for 57 consecutive patients with pyogenic spinal osteomyelitis who were treated between June 1987 and June 1995. Pain and weakness were the most common presenting symptoms. The mean duration of symptoms at the time of diagnosis was 10.6 weeks. Surgical indications included the presence or development of motor deficits with epidural compression and/or localized kyphotic deformities or the failure of medical therapy. RESULTS: Thirty-three patients underwent surgery as their initial treatment. Six additional patients experienced medical therapy failure and received subsequent surgical treatment. Seventeen patients were treated using an anterior approach only, 13 were treated using a posterior approach only, and 9 were treated using a combined anterior and posterior approach. After a minimal follow-up period of 24 months, 93% of the surgically treated patients showed neurological improvement or were neurologically intact, with a mean 16-degree decrease in localized kyphotic deformities and with solid bony fusion and resolution of pain for all patients. CONCLUSION: Early surgical decompression results in rapid improvement of neurological deficits, decreases in kyphotic deformities, and stabilization with bony fusion. The presence of active infection does not preclude the use of internal fixation. Nonsurgical management is indicated for patients with minimal or no neurological deficits and the absence of significant localized kyphotic deformities. However, 25% of patients who were initially treated nonsurgically experienced medical therapy failure and underwent surgical treatment.

Contrast-enhancing progressive multifocal leukoencephalopathy: radiological and pathological correlations: case report.

OBJECTIVE AND IMPORTANCE: Progressive multifocal leukoencephalopathy (PML), a demyelinating disease caused by the JC papovavirus, is an opportunistic infection afflicting patients with impaired cellular immunity. Although initially described in patients with hematological malignancies, PML has become associated with several other immunocompromised states, particularly human immunodeficiency virus (HIV) infection. There are numerous central nervous system manifestations in patients with acquired immunodeficiency syndrome. A major characteristic that distinguishes PML from other more common lesions, such as toxoplasmosis or non-Hodgkin's lymphoma, is the lack of contrast enhancement. We describe a case of PML that exhibits contrast enhancement, and we conclude that the diagnosis of PML must be considered in patients with HIV who have contrast-enhancing lesions. CLINICAL PRESENTATION: A 40-year-old woman presented with progressive hemiparesis, blurred vision, and ataxia. Magnetic resonance imaging revealed a contrast-enhancing lesion involving the left middle cerebellar peduncle, causing mild compression of the fourth ventricle. INTERVENTION: The patient underwent a stereotactic serial biopsy with the presumptive diagnosis of moderate- to high-grade glioma. Histological examination of the biopsy specimen revealed early PML. Subsequently, a test for HIV was obtained and the results were positive. CONCLUSION: We have reported another atypical radiographic characteristic of PML associated with HIV. We conclude that PML lesions can enhance after the administration of gadolinium. Therefore, the diagnosis of PML must be entertained in patients whose test results were positive for HIV with contrast-enhancing lesions and that a stereotactic serial biopsy may be necessary to provide a definitive diagnosis.

Disseminated ependymomas of the central nervous system.

Ependymomas are rare central nervous system (CNS) neoplasms that occasionally disseminate along the neuraxis or to extraneural sites. Definitive criteria predictive of dissemination have yet to be determined. One hundred forty patients with CNS ependymoma (88 primary spinal and 52 primary intracranial tumors) were surgically treated by the senior author (F.J.E.) between 1986 and 1994. Sixteen patients (11.4%) demonstrated tumor dissemination. The disseminated group consisted of 11 (12.5%) of 88 primary spinal and five (9.6%) of 52 primary intracranial ependymomas. The authors retrospectively reviewed the patients with CNS ependymoma and have identified several characteristics associated with dissemination from the primary tumor site. The mean time from diagnosis to dissemination was 6.8 years. The patients with disseminated disease were younger (16.8 vs. 28.3 years old, p = 0.02), had fewer gross-total resections (29% vs. 68%, p = 0.015), and had tumors with higher proliferative indices (MIB-1 staining, 13.14% vs. 2.06%, p = 0.02). High-grade tumors had a mean proliferation index of 21%, versus 2.4% and 1.6% for myxopapillary and low-grade tumors, respectively (p = 0.0003). In contrast to previous studies, tumor histology was the most significant variable for time to dissemination as determined by multivariate analysis (p = 0.008). Myxopapillary and high-grade tumors were 3.6 and 5.6 times more likely to have a shorter time to dissemination than low-grade tumors. In addition, dissemination is associated with a worse prognosis. At follow-up review, 31% of patients with disseminated disease had died compared to 7% of patients without dissemination (p = 0.04). It is concluded that younger patients with subtotal resections, myxopapillary or high-grade histology, and tumors with high proliferative indices are at substantial risk for the development of disseminated disease during their clinical course.

Laparoscopic nephrectomy in the first year of life.

A child was found antenatally to have a cystic right kidney on maternal ultrasound. This was evaluated in the immediate postnatal period with imaging studies and confirmed to be a multicystic, dysplastic kidney. Expectant management was followed; however, the kidney was found to be unchanged in size on a 6-month ultrasound and the parents elected surgical removal rather than continued medical surveillance. A nephrectomy was performed using laparoscopic techniques rather than standard open surgery. Operating time was less than 1 hour. The patient's recovery was unremarkable.

Single foetal death in twin pregnancies: review of the maternal and neonatal outcomes and management.

OBJECTIVE: To review the maternal and neonatal outcomes, and management of single foetal death in twin pregnancies. DATA SOURCES: Medline literature search (1950 to 1999) and hospital audit of single antepartum foetal deaths in twin pregnancy from 1993 through 1997. DATA SELECTION: Key words for literature search: twin pregnancy/pregnancies; single fetal death/demise. DATA EXTRACTION: Data were extracted and reviewed independently by the authors. DATA SYNTHESIS: During the study period, 182 (0.76%) of 23,804 deliveries involved twin pregnancies. Seven (3.8%) of the twin pregnancies were complicated by the death of one foetus. Single foetal death in a twin pregnancy in the late second and third trimesters is associated with significant morbidity and mortality in the surviving co-twin, especially in a pregnancy involving monochorionic twins. Management should be individualised; conservative management is preferred by most obstetricians. CONCLUSION: Single foetal death in twin pregnancies should be managed in a tertiary referral centre, where intensive foetal surveillance and adequate neonatal support are available. A multidisciplinary approach should be adopted.

Metastatic merkel cell tumour to the bladder.

Merkel cell tumour is becoming increasingly recognized. A case of Merkel cell tumour metastatic to the urinary bladder is presented. The primary site was a cutaneous lesion of the left hand which later metastasized to the axillary and supraclavicular lymph nodes before metastasizing to the bladder. This is believed to be the first reported case of metastatic Merkel cell tumour to the bladder.

A placebo controlled double blind study using perioperative prazosin in the prevention of urinary retention following inguinal hernia repair.

Acute urinary retention is a frequent complication following inguinal hernia repair. The smooth muscle of the bladder neck and the prostate have been demonstrated to be rich in alpha-1 adrenergic receptors. It has been postulated that the aetiology of acute urinary retention postoperatively is at least partially due to adrenergic stimulation; blocking these receptors may reduce the incidence of acute urinary retention. We have used prazosin in a double blind, placebo controlled study to establish its efficacy in the prevention of acute urinary retention in patients undergoing elective inguinal hernia repair. A total of 70 male patients were enrolled; 36 patients had been allocated active drug and 34 patients had been allocated placebo. Only two patients developed acute urinary retention. Both patients had been allocated prazosin and had received a general anaesthetic for their hernia surgery. In either arm of the study, a higher number of patients developing urinary retention would have been expected but this may be explained by the greater vigilance on urinary output by nursing staff aware that the trial was being conducted. On the basis of our findings, we do not recommend the routine use of perioperative prazosin with inguinal hernia repair. Further studies in high risk groups would be necessary to assess more fully the efficacy of prazosin in this situation.