Focal amplification of the androgen receptor gene in hormone-naive human prostate cancer.

BACKGROUND: Androgen receptor (AR)-gene amplification, found in 20-30% of castration-resistant prostate cancer (CRPCa) is proposed to develop as a consequence of hormone-deprivation therapy and be a prime cause of treatment failure. Here we investigate AR-gene amplification in cancers before hormone deprivation therapy. METHODS: A tissue microarray (TMA) series of 596 hormone-naive prostate cancers (HNPCas) was screened for chromosome X and AR-gene locus-specific copy number alterations using four-colour fluorescence in situ hybridisation. RESULTS: Both high level gain in chromosome X (≥4 fold; n=4, 0.7%) and locus-specific amplification of the AR-gene (n=6, 1%) were detected at low frequencies in HNPCa TMAs. Fluorescence in situ hybridisation mapping whole sections taken from the original HNPCa specimen blocks demonstrated that AR-gene amplifications exist in small foci of cells (≤ 600 nm, ≤1% of tumour volume). Patients with AR gene-locus-specific copy number gains had poorer prostate cancer-specific survival. CONCLUSION: Small clonal foci of cancer containing high level gain of the androgen receptor (AR)-gene develop before hormone deprivation therapy. Their small size makes detection by TMA inefficient and suggests a higher prevalence than that reported herein. It is hypothesised that a large proportion of AR-amplified CRPCa could pre-date hormone deprivation therapy and that these patients would potentially benefit from early total androgen ablation.

Prognostic value of PTEN loss in men with conservatively managed localised prostate cancer.

BACKGROUND: The natural history of prostate cancer is highly variable and difficult to predict. We report on the prognostic value of phosphatase and tensin homologue (PTEN) loss in a cohort of 675 men with conservatively managed prostate cancer diagnosed by transurethral resection of the prostate. METHODS: The PTEN status was assayed by immunohistochemistry (PTEN IHC) and fluorescent in situ hybridisation (PTEN FISH). The primary end point was death from prostate cancer. RESULTS: The PTEN IHC loss was observed in 18% cases. This was significantly associated with prostate cancer death in univariate analysis (hazard ratio (HR)=3.51; 95% CI 2.60-4.73; P=3.1 × 10(-14)). It was highly predictive of prostate cancer death in the 50% of patients with a low risk score based on Gleason score, PSA, Ki-67 and extent of disease (HR=7.4; 95% CI 2.2-24.6; P=0.012) ), but had no prognostic value in the higher risk patients. The PTEN FISH loss was only weakly associated with PTEN IHC loss (κ=0.5). Both PTEN FISH loss and amplification were univariately predictive of death from prostate cancer, but this was not maintained in the multivariate analyses. CONCLUSION: In low-risk patients, PTEN IHC loss adds prognostic value to Gleason score, PSA, Ki-67 and extent of disease.

Molecular characterisation of ERG, ETV1 and PTEN gene loci identifies patients at low and high risk of death from prostate cancer.

BACKGROUND: The discovery of ERG/ETV1 gene rearrangements and PTEN gene loss warrants investigation in a mechanism-based prognostic classification of prostate cancer (PCa). The study objective was to evaluate the potential clinical significance and natural history of different disease categories by combining ERG/ETV1 gene rearrangements and PTEN gene loss status. METHODS: We utilised fluorescence in situ hybridisation (FISH) assays to detect PTEN gene loss and ERG/ETV1 gene rearrangements in 308 conservatively managed PCa patients with survival outcome data. RESULTS: ERG/ETV1 gene rearrangements alone and PTEN gene loss alone both failed to show a link to survival in multivariate analyses. However, there was a strong interaction between ERG/ETV1 gene rearrangements and PTEN gene loss (P<0.001). The largest subgroup of patients (54%), lacking both PTEN gene loss and ERG/ETV1 gene rearrangements comprised a 'good prognosis' population exhibiting favourable cancer-specific survival (85.5% alive at 11 years). The presence of PTEN gene loss in the absence of ERG/ETV1 gene rearrangements identified a patient population (6%) with poorer cancer-specific survival that was highly significant (HR=4.87, P<0.001 in multivariate analysis, 13.7% survival at 11 years) when compared with the 'good prognosis' group. ERG/ETV1 gene rearrangements and PTEN gene loss status should now prospectively be incorporated into a predictive model to establish whether predictive performance is improved. CONCLUSIONS: Our data suggest that FISH studies of PTEN gene loss and ERG/ETV1 gene rearrangements could be pursued for patient stratification, selection and hypothesis-generating subgroup analyses in future PCa clinical trials and potentially in patient management.

rHVDM: an R package to predict the activity and targets of a transcription factor.

SUMMARY: Highly parallel genomic platforms like microarrays often present researchers with long lists of differentially expressed genes but contain little or no information on how these genes are regulated. rHVDM is a novel R package which uses gene expression time course data to predict the activity and targets of a transcription factor. In the first step, rHVDM uses a small number of known targets to derive the activity profile of a given transcription factor. Then, in a subsequent step, this activity profile is used to predict other putative targets of that transcription factor. A dynamic and mechanistic model of gene expression is at the heart of the technique. Measurement error is taken into account during the process, which allows an objective assessment of the robustness of fit and, therefore, the quality of the predictions. The package relies on efficient algorithms and vectorization to accomplish potentially time consuming tasks including optimization and differential equation integration. We demonstrate the efficiency and accuracy of rHVDM by examining the activity of the tumour-suppressing transcription factor, p53. AVAILABILITY: The version of the package presented here (1.8.1) is freely available from the Bioconductor Web site (http://bioconductor.org/packages/2.3/bioc/html/rHVDM.html).

Prostate cancer evolution from multilineage primary to single lineage metastases with implications for liquid biopsy.

The evolutionary progression from primary to metastatic prostate cancer is largely uncharted, and the implications for liquid biopsy are unexplored. We infer detailed reconstructions of tumor phylogenies in ten prostate cancer patients with fatal disease, and investigate them in conjunction with histopathology and tumor DNA extracted from blood and cerebrospinal fluid. Substantial evolution occurs within the prostate, resulting in branching into multiple spatially intermixed lineages. One dominant lineage emerges that initiates and drives systemic metastasis, where polyclonal seeding between sites is common. Routes to metastasis differ between patients, and likely genetic drivers of metastasis distinguish the metastatic lineage from the lineage that remains confined to the prostate within each patient. Body fluids capture features of the dominant lineage, and subclonal expansions that occur in the metastatic phase are non-uniformly represented. Cerebrospinal fluid analysis reveals lineages not detected in blood-borne DNA, suggesting possible clinical utility.

Horizontally-acquired HIV infection in Kenyan and Swazi children.

Despite many reports of HIV-infected African children who have HIV-uninfected mothers, little is known about the extent and modes of horizontal HIV transmission in African children. We estimated the extent of horizontal HIV transmission in Swazi children by comparing child and mother HIV statuses in the 2006-2007 Swaziland Demographic and Health Survey (DHS). To identify correlates of horizontal HIV transmission, we conducted a case-control study of Kenyan children with horizontally acquired HIV infections and their uninfected siblings. Of 50 HIV-positive Swazi children in the DHS, 11 (weighted percent = 20, 95% confidence interval 11-33%) had HIV-negative mothers. These 11 children represented 0.6% of all Swazi children aged 2-12 who lived with their mothers. In the Kenyan study, children with horizontally acquired HIV infections had more kinds of blood exposures than their uninfected siblings. In particular, punctures related to health care for suspected malaria (phlebotomy, injection and infusion), injections while hospitalized and dental surgery (especially by informal providers) were more common in infected children. Horizontal HIV transmission appears to be common in some sub-Saharan African countries, and blood exposures seem to be the most likely routes of transmission. Rigorous surveillance and investigation of horizontally acquired HIV infection in children are urgently needed, along with universal public education about risks of specific blood exposures and ways to avoid them.

Diverse blood exposures associated with incident HIV infection in Calabar, Nigeria.

Few types of blood exposures have been assessed in relation to incident HIV infection in sub-Saharan Africa, despite evidence that penile-vaginal sex cannot account for the epidemic in the region. To investigate correlates of incident HIV infection in Calabar, Nigeria, we surveyed clients at voluntary HIV counselling and testing centres. Participating clients who tested multiple times were generally similar to those testing only once in terms of demographic characteristics, sexual and blood exposures and HIV prevalence. Blood exposures were common. Serial testers had a 10% annual incidence of HIV infection. Seroconverters and seronegative serial testers were similar on most demographic characteristics and sexual exposures. However, seroconverters were more likely than seronegatives to report blood exposures during the test interval, both for most specific exposures as well as summary measures of blood exposures. In particular, seroconverters were substantially more likely to report one of a set of blood exposures that cannot be explained as a consequence of unprotected vaginal sex or of health care for symptoms of HIV infection (adjusted odds ratio = 6.6, 95% confidence interval = 1.2-38). The study design we used is an inexpensive approach for describing the local epidemiology of HIV transmission and can also serve as the foundation for more definitive investigations that employ contact tracing and sequencing of HIV DNA.

Evaluation of a patient referral contact tracing programme for hepatitis B and C virus infection in drug injectors.

Effective contact tracing for hepatitis B virus (HBV) and hepatitis C virus (HCV) infection could enhance disease control, especially in populations with low HBV vaccination rates and high prevalence of untreated HCV infection. We evaluated a low-cost approach to HBV/HCV contact tracing in injection drug users (IDUs). Index cases (n=26) were IDUs who seroconverted to HBV and/or HCV during a prospective cohort study in Seattle. Interviewers elicited index cases' recent injection partners and administered recall cues and other techniques to boost recall. Index cases received vouchers for free hepatitis testing, which they were to give to locatable partners. Persons redeeming vouchers also received small monetary incentives. Most (26/40) seroconverters participated in the paid contact interviews. Index cases reported many partners (mean=17), and in the aggregate, index cases indicated they could refer more than one third of their elicited partners for testing. Overall, only 17 persons were ultimately referred and just eight of these were confirmed as partners sought for referral. The supplementary elicitation techniques, and especially the recall cues, increased reporting of injection partners substantially. The injection network constructed from reported partnerships was mostly connected and cyclic. Successful contact tracing in IDUs likely requires active involvement by public health staff to locate and notify exposed injection partners.

TEAD1 and c-Cbl are novel prostate basal cell markers that correlate with poor clinical outcome in prostate cancer.

Prostate cancer is the most frequently diagnosed male cancer, and its clinical outcome is difficult to predict. The disease may involve the inappropriate expression of genes that normally control the proliferation of epithelial cells in the basal layer and their differentiation into luminal cells. Our aim was to identify novel basal cell markers and assess their prognostic and functional significance in prostate cancer. RNA from basal and luminal cells isolated from benign tissue by immunoguided laser-capture microdissection was subjected to expression profiling. We identified 112 and 267 genes defining basal and luminal populations, respectively. The transcription factor TEAD1 and the ubiquitin ligase c-Cbl were identified as novel basal cell markers. Knockdown of either marker using siRNA in prostate cell lines led to decreased cell growth in PC3 and disrupted acinar formation in a 3D culture system of RWPE1. Analyses of prostate cancer tissue microarray staining established that increased protein levels of either marker were associated with decreased patient survival independent of other clinicopathological metrics. These data are consistent with basal features impacting on the development and clinical course of prostate cancers.

Impacts of gold mine waste disposal on deepwater fish in a pristine tropical marine system.

Little is known about the impacts of mine waste disposal, including deep-sea tailings, on tropical marine environments and this study presents the first account of this impact on deepwater fish communities. The Lihir gold mine in Papua New Guinea has deposited both excavated overburden and processed tailings slurry into the coastal environment since 1997. The abundances of fish species and trace metal concentrations in their tissues were compared between sites adjacent to and away from the mine. In this study (1999-2002), 975 fish of 98 species were caught. Significantly fewer fish were caught close to the mine than in neighbouring regions; the highest numbers were in regions distant from the mine. The catch rates of nine of the 17 most abundant species were lowest, and in three species were highest, close to the mine. There appears to be limited contamination in fish tissues caused by trace metals disposed as mine waste. Although arsenic (several species) and mercury (one species) were found in concentrations above Australian food standards. However, as in the baseline (pre-mine) sampling, it appears they are accumulating these metals mostly from naturally-occurring sources rather than the mine waste.

Healthy Hunger-Free Kids Act Increases Phytochemicals in Menus and Curriculum Furthers Identification of Phytochemical-Rich Foods.

OBJECTIVE: This study evaluated whether providing the Fruits and Vegetables (F/V) required by the Healthy Hunger-Free Kids Act (HHFKA) increased phytochemical/antioxidant content of school lunches. Additionally, the ability of adolescents to apply their nutritional knowledge following participation in a nutrition-focused science-based curriculum was assessed. METHODS: Changes in antioxidant/phytochemical content from F/V offered in school lunch menus were analyzed Pre-and Post-HHFKA. Food logs completed by 717 youth aged 10-18 were analyzed for correctly identifying "fighting foods". RESULTS: Significant increases in antioxidant/phytochemical content resulted following implementation of HHFKA (P<0.05). Seventy-five percent [0, 100] of the time students accurately identified "fighting foods" in their one-day in-school food log (n=468). CONCLUSIONS AND IMPLICATIONS: Creatively incorporating nutrition education into core curriculum, when paired with a supportive built environment that increases F/V access (HHFKA), generates a multilevel intervention promoting F/V consumption among school-aged youth.

Long-term BP monitoring in the evaluation of antihypertensive therapy.

Noninvasive BP monitoring was performed in hypertensive patients before and during placebo therapy and before and during therapy with the long-acting peripheral alpha-adrenergic receptor antagonist, terazosin hydrochloride. Placebo therapy did not result in significant changes in casual BP or in averages of whole-day, daytime, or nighttime BPs. Short-term therapy with terazosin did not induce significant changes in casual supine or daytime BPs. However, whole-day BP monitoring disclosed that nighttime BPs were lower during shortterm therapy. Moreover, the circadian pattern of BP was shifted downward during terazosin therapy. Long-term therapy with terazosin resulted in significant changes in BP. All BP values were lowered significantly. The differences in the circadian BP pattern between placebo and long-term terazosin therapy show that in these patients BP was lowered throughout the 24 hours of the day. The results of the study emphasize the usefulness of 24-hour BP monitoring in the evaluation of the effectiveness of long-acting antihypertensive agents.

Pharmacokinetics of single-dose rectal zonisamide administration in normal dogs.

BACKGROUND: Few medications are available for parental administration to animals with seizures. Rectal administration of medications is often used if the animal cannot be administered oral medications. HYPOTHESIS/OBJECTIVES: To determine the pharmacokinetic differences in zonisamide when administered rectally in either of 2 vehicles and p.o. to dogs. ANIMALS: Eight healthy research dogs. METHODS: Randomized cross-over design. Zonisamide, 10 mg/kg, was administered rectally in polyethylene glycol (PEG-R), rectally in water (H2O-R), and as an oral capsule. Plasma zonisamide concentrations were measured until 72 hours after administration. Zonisamide was quantitated by HPLC and plasma concentration versus time curve data was analyzed by using noncompartmental modeling. RESULTS: Mean maximum plasma zonisamide concentrations (µg/mL) were significantly higher after oral administration (11.56 ± 4.04) compared to H2O-R (5.00 ± 1.83) (P = .004). Disappearance half-life (hours) and mean time to maximum concentration (hours) were not significantly different between methods of administration. Mean relative bioavailability of PEG-R (85 ± 69%) was significantly higher than that of H2O-R (53 ± 37%) (P = .039). Dogs tolerated all dosing forms with no evidence of adverse effects. CONCLUSIONS AND CLINICAL IMPORTANCE: The vehicle in which zonisamide is dissolved influences rectal bioavailability, with PEG preferred to H2O-R. Because of the prolonged time to maximum concentration, rectal administration of zonisamide should not be used to treat status epilepticus in dogs. A dose higher than what was used in this study might be necessary, if currently recommended minimum therapeutic concentrations (10 µg/mL) are to be achieved with a single-dose administration.

Disparate relationships between blood pressure and left ventricular mass in patients with and without left ventricular hypertrophy.

The relationship between casual blood pressure and left ventricular (LV) mass has been reported to be fairly weak in hypertensive patients. In this study we analyzed this relationship using noninvasive devices to monitor blood pressure for 24 hours in ambulatory patients and M-mode echocardiography to determine LV mass. Among the 33 patients with hypertension, 21 had echocardiographic LV hypertrophy (LV mass greater than 250 g). Patients with LV hypertrophy did not differ significantly from patients without hypertrophy with respect to age or casual systolic or diastolic blood pressure. The averages of whole-day systolic and diastolic blood pressures were 146 +/- 17 (SD) over 90 +/- 12 and 136 +/- 16 over 89 +/- 12 mm Hg, respectively. The relationship between whole-day average systolic blood pressure and LV mass was significantly positive (r = 0.66, p less than 0.05) in patients without hypertrophy but was not significant in patients with LV hypertrophy (r = -0.24). Similarly, the relationship between whole-day average diastolic blood pressure and LV mass was significantly positive in the former group (r = 0.64, p less than 0.05) but significantly negative in hypertensive patients with LV hypertrophy (r = -0.67, p less than 0.01). Thus, blood pressure correlates positively with LV mass only in patients without cardiac hypertrophy. In hypertensive patients with LV hypertrophy, factors additional to the high blood pressure itself must participate in the regulation of LV mass.

Doppler echocardiographic assessment of left ventricular systolic and diastolic function in mild hypertension.

Abnormalities in left ventricular (LV) wall thickness and mass have been demonstrated in patients with mild hypertension utilizing M-mode echocardiography. In addition, studies using radionuclide angiography have demonstrated abnormalities in early diastolic LV filling in asymptomatic hypertensive patients with normal ejection fraction and cardiac output. Recently, Doppler recordings of flow velocity in the ascending aorta and through the mitral valve have been shown to provide useful information about LV function. To determine whether flow abnormalities could be detected in patients with mild hypertension, we recorded Doppler aortic and mitral valve flow velocities in 21 men with mild hypertension. Casual systolic blood pressure was 147 +/- 18 mm Hg (mean +/- SD) and diastolic blood pressure was 96 +/- 9 mm Hg. LV mass (310 +/- 75 g) was elevated (i.e., above the 95% normal prediction interval) in 8 of 19 patients who underwent M-mode echocardiography; LV ejection fraction was normal in all patients (mean, 80%). As in previous studies in normal subjects, we found in these hypertensive patients an inverse correlation between age and both aortic peak flow velocity (r = -0.51, p less than 0.05) and transmitral early diastolic peak flow velocity (r = -0.44, p less than 0.05) and a positive relationship between age and mitral valve late diastolic peak flow velocity (r = 0.73, p less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

A vasodilator that avoids renin stimulation and fluid retention: antihypertensive treatment with trimazosin.

Trimazosin was given for periods of at least 6 mo to 25 patients with mild to moderate essential hypertension. In doses of 300 to 900 mg dialy trimazosin alone led to blood pressure control (supine diastolic blood pressure less than 90 mm Hg with a fall of at least 10 mm Hg) in 16 patients (64%). Despite the decrements in blood pressure there were no changes in body weight or creatinine clearance. There was also no changes in plasma renin activity or urinary aldosterone excretion rate. Although patients with high control renin values appeared to have greater blood pressure decreases than those with low renin values, responsiveness to treatment was not associated with consistent effects of trimazosin on the renin-angiotensin system. Trimazosin induced a small decrease in plasma total cholesterol concentration. In seven patients whose blood pressures were not controlled by trimazosin alone, the addition of polythiazide led to decreased blood pressure and in five control of pressure was achieved. Thus, trimazosin is an effective antihypertensive when given by itself or in combination with a diuretic. Its mechanism of action has not been established, but its ability to induce vasodilation without concomitant sodium retention or stimulation of the renin axis may be an important factor in its effectiveness.

Child abuse, cardiopulmonary resuscitation, and rib fractures.

Rib fractures have occasionally been described in children receiving cardiopulmonary resuscitation (CPR). Because child abuse is sometimes suspected in these cases, it is both medically and legally important to establish whether the rib fractures are secondary to abuse or CPR. One hundred thirteen children, including 41 victims of child abuse, 50 patients who had CPR, and 22 patients who had rib fractures, were studied. Twenty-nine patients had rib fractures; 14/29 (48%) were abusive. Other causes of fracture were: motor vehicle accidents (four), rickets/osteoporosis (five), surgery (five), and osteogenesis imperfecta (one). In spite of prolonged resuscitation performed with variable degrees of skill, no fractures could be attributed to CPR. On the other hand, rib fractures occurred frequently in abused children (6/41 or 15%). Abusive fractures were often multiple, of different ages, and affected multiple adjacent ribs. Patients with abusive rib fracture also had other physical and radiologic signs of abuse or neglect.

Use of bacterial antigen detection in the diagnosis of pediatric lower respiratory tract infections.

Two immunochemical methods were used to identify Haemophilus influenzae and Streptococcus pneumoniae capsular antigens in the urine and serum of 162 children with acute lower respiratory tract infection. These methods were compared with standard bacterial blood culture. Viral and mycoplasma cultures of respiratory secretions were obtained simultaneously to determine the frequency of antigenuria at the time of nonbacterial acute lower respiratory tract infection. Urine from groups of well children and children with acute otitis media was tested for capsular antigens to determine the incidence of antigenuria. Antigenuria was found in 24% of children 2 months to 18 years of age with acute lower respiratory tract infection compared with a 2% incidence of bacteremia. Antigenuria was found in 4% of asymptomatic children and 16% of children with acute otitis media. One third of children with symptoms of acute lower respiratory tract infection and viral isolates from the oropharynx had bacterial antigenuria. The sixfold increase in frequency of bacterial antigenuria in children at the time of lower respiratory symptoms suggests that bacterial acute lower respiratory tract infection may be more common than identified by traditional culture techniques. Because bacterial antigen may come from other sites such as the middle ear, further studies are needed to determine the role of antigen detection in the diagnosis of pediatric acute lower respiratory tract infection.

Long-term propranolol therapy for angina pectoris.

Sixty-three patients with stable, severe typical angina pectoris (New York Heart Association functional class III or IV) were treated with propranolol and studied prospectively with a follow-up period of 5 to 8 years to assess the rate of complications and long-term effectiveness after an initial control period. The patients' mean age was 56 years; the mean daily dose of propranolol was 255 mg. The average yearly mortality rate was 3.8 percent with a cumulative 5 year mortality rate of 19 percent. Patients whose reduction of angina with propranolol was less than 50 percent had a nearly four-fold greater mortality rate than those whose reduction was 50 percent or more (P less than 0.01). Thirty-two percent of patients per year were angina-free with propranolol and 84 percent per year had 50 percent or more reduction in anginal episodes. There was no evidence for tachyphylaxis. Heart failure developed in 25 percent of patients, two thirds of whom had either congestive heart failure with an acute infarction or a prior history of congestive heart failure. All patients whose initial cardiothoracic ratio was greater than 0.5 had heart failure during the first 3 years of propranolol therapy. Of 12 patients who had an acute infarction during therapy, 7 died, 6 with cardiogenic shock; in contrast, 8 of 9 patients who had congestive heart failure without acute infarction survived. Eight percent of patients had other significant side effects, including gastrointestinal symptoms (three patients), hallucinations (one) and postural hypotension (one). The occurrence of asthma in three patients was dose-related and did not require drug discontinuation. Propanolol is an effective form of long-term therapy for severe angina pectoris; it does not induce tachyphylaxis or increase the overall mortality rate, although it may increase the risk of cardiogenic shock in acute myocardial infarction. Previous history of congestive heart failure, a cardiothoracic ratio of more than 0.5 without overt heart failure and mild asthma are relative contraindications. A 50 percent or greater reduction in anginal pain with propranolol predicts a low mortality group.