Liquid chromatography tandem mass spectrometry for plasma metadrenalines.

Evidence is accumulating which may result in plasma free metadrenalines (PMets) becoming the preferred test for diagnosing phaeochromocytoma and paraganglioma. Moreover, increased availability and benefits over other analytical methods like liquid chromatography with electrochemical detection and immunoassay are causing liquid chromatography tandem mass spectrometry (LC-MS/MS) to become the method of choice for PMet measurement. This review explores the evidence-base supporting this, and summarises published LC-MS/MS analytical methods for PMet analysis. Key aspects of methods (including SPE extraction, HILIC chromatography, MRM MS-detection and standardisation) are discussed. Common causes of analytical interference (e.g. ion suppression/enhancement, ionic cross talk, in source transformation and isobaric interferences) are outlined to illustrate the importance of sample purification and chromatographic resolution. The importance of supine, fasting sampling and Bayesian interpretation against supine, fasting reference intervals are explained, as well as the importance of age-specific reference intervals for normetadrenaline. Confounding factors like diet, drugs, renal function and acute illness are explored, along with potential strategies to address these (e.g. CKD-specific reference intervals).

Associations between participation in family activities and adolescent school problems.

INTRODUCTION: Adolescent risk outcomes related to school issues are widespread, with about 20% parents reporting poor school engagement amongst their youth. Previous literature suggests that adolescents who report strong bonds with their parents are often identified as being less likely to engage in risky behaviours, such as substance use. The current study sought to examine the association between the frequencies of selected family activities and school problems amongst adolescents after adjustments for family connectedness and other characteristics. METHODS: Data were drawn from the National Longitudinal Survey of Youth, 1997. Of the 8984 youth interviewed, 3855 also had a sibling interviewed who met the selection criteria. School problem outcomes measured were suspension occurrence, poor grades and highest grade completed low for age. Independent variables of interest were self-reported frequency of family dinner, fun and religious activities in a typical week. Multivariable logistic models were estimated for each outcome, and multivariable linear probability models were estimated adjusting for family fixed effects. RESULTS: Adjusting for family connectedness, there were significant associations between certain family activities and adolescent school problem measures. However, these results did not remain significant in models with family fixed effects, suggesting that associations could be driven by family-level confounders. DISCUSSION: This study did not find strong evidence of a protective relationship between family activities and school problems. Therefore, it suggested that programme and policymakers be cautious in overstating the importance of family activities in preventing adolescent risk outcomes until true causal relationships can be determined.

Panitumumab in the treatment of colon cancer: A biomarker dilemma.

Panitumumab is a fully human monoclonal antibody targeting epidermal growth factor receptor (EGFR) approved for use in colorectal cancer (CRC). Critical information regarding biomarkers in CRC has been discovered through the investigation of panitumumab treatment. The discovery of anti-EGFR resistance in the setting of Kirsten rat sarcoma viral oncogene (KRAS) and more recently, neuroblastoma RAS viral oncogene (NRAS) mutations in CRC has changed the focus of therapy for metastatic disease to one based on the molecular characteristics of the tumor. This review will give a brief background on panitumumab and its current uses in CRC.

Defining a holistic pain-relieving approach to wound care via a drug free polymeric membrane dressing.

Wound care practice continuously demonstrates that healing cannot be adequately controlled if a patient's experience of pain is not managed effectively. Current pain management guidelines do not account for the holistic treatment of pain emanating from a wound-an environment of uncontrolled or rogue inflammation, neuropathy and neuroischaemia. This article investigates how polymeric membrane dressings can interact with the pathology of wounds to correct abnormalities in pain pathways of the nervous system and dampen problematic ongoing pain to enhance the clinical picture of wound healing.

Clinical development of levetiracetam for amyotrophic lateral sclerosis.

This month's Spotlight on... focuses on the current clinical development of the antiepileptic drug levetiracetam for amyotrophic lateral sclerosis. We highlight the experimental rationale behind its progress into patient cohorts with regards to targeting three currently untreatable aspects of human amyotrophic lateral sclerosis: cramps, spasticity and disease progression.

Pharmacokinetically guided phase I trial of topotecan and etoposide phosphate in recurrent ovarian cancer.

A pharmacokinetically guided phase I study of topotecan and etoposide phosphate was conducted in recurrent ovarian cancer. The scheduling of the topoisomerase I and II inhibitors was determined using in vitro activity data. All patients had recurrent disease following prior platinum-containing chemotherapy. Patients had a World Health Organisation performance status of 0-2 and adequate bone marrow, renal and hepatic function. Treatment was with topotecan intravenously for 5 days followed immediately by a 5-day intravenous infusion of etoposide phosphate (EP), with pharmacokinetically guided dose adjustment. Plasma etoposide levels were measured on days 2 and 4 of the infusion. A total of 21 patients entered the study. In all, 48% were platinum resistant and 71% had received prior paclitaxel. The main toxicities were haematological, short lived and reversible. A total of 29% of patients experienced grade 4 thrombocytopenia and 66% grade 4 neutropenia after the first cycle. Neutropenia and thrombocytopenia was dose limiting. The maximum-tolerated dose was topotecan 0.85 mg m(-2) day(-1) days 1-5 followed immediately by a 5-day infusion of EP at a plasma concentration of 1 mug ml(-1). The response rate (RR) was 28% in 18 evaluable patients. There was marked interpatient variability in topoisomerase IIalpha levels measured from peripheral lymphocytes, with no observed increase following topotecan. This regimen of topotecan followed by EP demonstrated good activity in recurrent ovarian cancer and was noncrossresistant with paclitaxel. Both the toxicity and RR was higher than would be expected from the single agent data, in keeping with synergy of action.

Molecular mechanisms of cerebrospinal fluid production.

The epithelial cells of the choroid plexuses secrete cerebrospinal fluid (CSF), by a process which involves the transport of Na(+), Cl(-) and HCO(3)(-) from the blood to the ventricles of the brain. The unidirectional transport of ions is achieved due to the polarity of the epithelium, i.e. the ion transport proteins in the blood-facing (basolateral) membrane are different to those in the ventricular (apical) membrane. The movement of ions creates an osmotic gradient which drives the secretion of H(2)O. A variety of methods (e.g. isotope flux studies, electrophysiological, RT-PCR, in situ hybridization and immunocytochemistry) have been used to determine the expression of ion transporters and channels in the choroid plexus epithelium. Most of these transporters have now been localized to specific membranes. For example, Na(+)-K(+)ATPase, K(+) channels and Na(+)-2Cl(-)-K(+) cotransporters are expressed in the apical membrane. By contrast the basolateral membrane contains Cl(-)- HCO(3) exchangers, a variety of Na(+) coupled HCO(3)(-) transporters and K(+)-Cl(-) cotransporters. Aquaporin 1 mediates water transport at the apical membrane, but the route across the basolateral membrane is unknown. A model of CSF secretion by the mammalian choroid plexus is proposed which accommodates these proteins. The model also explains the mechanisms by which K(+) is transported from the CSF to the blood.

Predictors of infection with Trichomonas vaginalis: a prospective study of low income African-American adolescent females.

OBJECTIVES: To identify psychosocial predictors of Trichomonas vaginalis infection among low income African-American adolescent females living in a high risk urban area of the United States. METHODS: Baseline plus 6 and 12 month follow up data collected as part of an HIV prevention intervention trial were utilised. The baseline sample consisted of 522 African-American females, 14-18 years of age. Recruitment sites were located in low income neighbourhoods of Birmingham, Alabama, characterised by high rates of unemployment, substance abuse, violence, teenage pregnancy, and sexually transmitted infections. Self administered vaginal swab specimens were cultured for T vaginalis. Baseline measures collected as part of a self administered survey and face to face interviews were used to predict subsequent infection with T vaginalis at any of the three assessment periods conducted over the span of 1 year. RESULTS: At baseline, 12.9% were diagnosed with T vaginalis. At the 6 and 12 month follow ups, T vaginalis was diagnosed in 8.9% and 10.2%, respectively. The strongest multivariate predictor of T vaginalis infection was biologically confirmed marijuana use; those using marijuana were more than six times as likely to test positive for T vaginalis (adjusted odds ratio (AOR) = 6.2, p = 0.0003). Other multivariate predictors were reporting that typical sex partners were at least 5 years older (AOR = 2.6; p = 0.005), reporting sex with non-steady partners (AOR = 1.9; p = 0.02), and history of delinquency (AOR = 1.3; p = 0.02). The odds of testing positive increased by 31% for every one unit increase on a six item scale measure of delinquency. CONCLUSIONS: Infection with T vaginalis was common and significant multivariate predictors comprised a constellation of problem behaviours, each of which are potentially amenable to behavioural intervention.

Production of antigen-specific human monoclonal antibodies: comparison of mice carrying IgH/kappa or IgH/kappa/lambda transloci.

Here we compare human monoclonal antibody (MAb) production from mouse strains that carry disruptions of their endogenous mouse IgH/IgK loci and harbor human IgM + Igkappa(BABkappa) or human IgM + Igkappa + IgA transloci (BABkappa,lambda). We found that whereas both strains proved effective for the isolation of antigen-specific IgM antibodies, many of the IgM MAbs elicited from BABkappa comprise human mu chains that are associated with mouse lambda chains. In contrast, BABkappa,lambda mice gave rise to fully functional, polymeric human IgM antibodies comprising both human IgH and human IgL chains. Therefore, the inclusion of a human Iglambda translocus (in addition to the human IgH + Igkappa transloci) not only diminishes problems of endogenous mouse Iglambda expression but also provides a strain of mice that yields fully human MAbs to a wide range of antigens, as witnessed by the isolation of MAbs to human blood cells, tumor cell lines, and an immunoglobulin idiotype.

Direct association of Bloom's syndrome gene product with the human mismatch repair protein MLH1.

Bloom's syndrome (BS) is a rare genetic disorder characterised by genomic instability and cancer susceptibility. BLM, the gene mutated in BS, encodes a member of the RecQ family of DNA helicases. Here, we identify hMLH1, which is involved in mismatch repair (MMR) and recombination, as a protein that directly interacts with BLM both in vivo and in vitro, and that the two proteins co-localise to discrete nuclear foci. The interaction between BLM and hMLH1 appears to have been evolutionarily conserved, as Sgs1p, the Saccharomyces cerevisiae homologue of BLM, interacts with yeast Mlh1p. However, cell extracts derived from BS patients show no obvious defects in MMR compared to wild-type- and BLM-complemented BS cell extracts. We conclude that the hMLH1-BLM interaction is not essential for post-replicative MMR, but, more likely, is required for some aspect of genetic recombination.

Parent-adolescent communication and sexual risk behaviors among African American adolescent females.

OBJECTIVE: To examine associations between parent-adolescent communication about sex-related topics and the sex-related communication and practices of African American adolescent females with partners, as well as their perceived ability to negotiate safer sex. DESIGN: A theory-guided survey and structured interview were administered to 522 sexually active African American females 14 to 18 years old. Recruitment sites were neighborhoods with high rates of unemployment, substance abuse, violence, and sexually transmitted diseases. Multivariate analyses, controlling for observed covariates, were used to identify the association of less frequent parent-adolescent communication with multiple assessed outcomes. RESULTS: Less frequent parent-adolescent communication (scores below the median) was associated with adolescents' non-use of contraceptives in the past 6 months (adjusted odds ratio [AOR] = 1.7) and non-use of contraceptives during the last 5 sexual encounters (AOR = 1.6). Less communication increased the odds of never using condoms in the past month (AOR = 1.6), during the last 5 sexual encounters (AOR = 1.7), and at last intercourse (AOR = 1.7). Less communication was also associated with less communication between adolescents and their sex partners (AOR = 3.3) and lower self-efficacy to negotiate safer sex (AOR = 1.8). CONCLUSIONS: The findings demonstrate the importance of involving parents in human immunodeficiency virus/sexually transmitted disease and pregnancy prevention efforts directed at female adolescents. Pediatricians and other clinicians can play an important role in facilitating parent-adolescent communication about sexual activity.

HIV/STD-protective benefits of living with mothers in perceived supportive families: a study of high-risk African American female teens.

BACKGROUND: The joint influence of living with the mother in a perceived supportive family may be an important HIV/STD-protective factor among sexually active female adolescents. METHODS: Sexually active African American female adolescents (N = 522) completed a self-administered survey and structured interview. Adolescents scoring high on family support and reporting that their mother lived with them were compared with the remaining adolescents in respect to unprotected vaginal sex (past 30 days), sex with a non-steady partner (past 6 months), communication with sex partners, attitudes toward condoms, and perceived ability to negotiate condom use. Logistic regression analyses controlled for the influence of parent-adolescent communication about sex and parental monitoring. RESULTS: Adolescents residing with their mothers in a perceived supportive family were more likely to communicate with their sex partners about sexual risk (OR = 1.53). They were less likely to report sex with a non-steady partner (OR = 0.51) or having unprotected sex with a steady partner (OR = 0.52) or any partner (OR = 0.55). CONCLUSIONS: Controlled analyses suggest that living with the mother in a perceived supportive family is an important HIV/STD-protective factor among female adolescents. HIV/STD prevention programs for female adolescents that include the mothers may promote positive and lasting effects.

Condom carrying is not associated with condom use and lower prevalence of sexually transmitted diseases among minority adolescent females.

BACKGROUND: Most of the studies associated with condom carrying and use have been conducted with adults. Because minority teenage females are particularly at risk for STD/HIV infection, further investigations specifically focusing on this population are warranted. GOAL: To determine whether observed condom carrying among adolescent females was associated with multiple measures of self-reported condom use, self-reported history of sexually transmitted diseases, and prevalence of biologically confirmed sexually transmitted diseases. METHODS: For this study, 522 sexually active African American adolescent females were recruited from low-income neighborhoods in Birmingham, Alabama. Measures of self-reported condom use, STD history, and condom carrying were collected. Adolescents were also tested for three prevalent sexually transmitted diseases. RESULTS: At the time of the assessment, 8% of the adolescents were observed to have a condom with them. Condom carrying was not found to be significantly associated with condom use and prevalence of sexually transmitted diseases. CONCLUSION: Condom carrying may not be an important outcome of sexually transmitted disease/HIV prevention programs designed to reduce HIV/sexually transmitted disease risk among adolescent females.

Role of the Bloom's syndrome helicase in maintenance of genome stability.

The RecQ family of DNA helicases has members in all organisms analysed. In humans, defects in three family members are associated with disease conditions: BLM is defective in Bloom's syndrome, WRN in Werner's syndrome and RTS in Rothmund-Thomson syndrome. In each case, cells from affected individuals show inherent genomic instability. The focus of our work is the Bloom's syndrome gene and its product, BLM. Here, we review the latest information concerning the roles of BLM in the maintenance of genome integrity.

Correlates of using dual methods for sexually transmitted diseases and pregnancy prevention among high-risk African-American female teens.

PURPOSE: To identify correlates of consistent dual-method use among African-American female adolescents at risk of sexually transmitted diseases (STDs) and pregnancy. METHODS: A convenience sample of 522 sexually active female teens attending adolescent medicine clinics, health department clinics, and school health classes volunteered. Recruitment sites were in low-income neighborhoods of Birmingham, Alabama. Adolescents completed a questionnaire and a face-to-face interview and provided vaginal swab specimens for laboratory diagnosis of STDs. Those reporting use of condoms and at least one other method of contraception, for each of the last five occasions they had sex were classified as consistent dual-method users. The questionnaire assessed frequency of adolescents' communication with their parents and partners about sex. The questionnaire also assessed two measures of parental supervision and adolescents' desire to avoid pregnancy. Multiple logistic regression assessed the independent contribution of each correlate of consistent dual-method use. RESULTS: Seventy-one adolescents (13.6%) were classified as consistent dual-method users. A strong desire to avoid pregnancy was the most influential correlate of consistent dual-method use [odds ratio (OR) =2.3]. Adolescents reporting that their parents generally knew whom they were with (OR = 2.0) and those reporting more frequent communication with parents (OR = 1.9) were also more likely to be consistent dual users. CONCLUSION: The findings suggest the need for research to examine the efficacy of interventions building on adolescent females' desire to avoid pregnancy. Study findings also suggest that interventions promoting improved parent-adolescent communication and improved parental supervision may contribute to adolescents' use of dual methods for STD and pregnancy prevention.

Dating violence and the sexual health of black adolescent females.

OBJECTIVE: This study examines the association between having a history of dating violence and the sexual health of adolescent females. METHODS: Black adolescent females (n = 522) completed a survey that assessed dating violence, defined as ever having a physically abusive boyfriend, and an interview that assessed sexual behaviors. RESULTS: Dating violence was reported by 18.4% of adolescents (n = 96). Adolescents with a history of dating violence were, in the past 6 months, 2.8 times more likely to have a sexually transmitted disease, 2.8 times more likely to have nonmonogamous male partners, and half as likely to use condoms consistently. Furthermore, adolescents with a history of dating violence were significantly more likely to fear the perceived consequences of negotiating condom use (odds ratio [OR] = 2.8); fear talking with their partner about pregnancy prevention (OR = 2.6); have a higher perceived risk of acquiring a sexually transmitted disease (OR = 2.1); perceive less control over their sexuality (OR = 2.4); have peer norms nonsupportive of using condoms (OR = 3.1); and have norms nonsupportive of having a healthy relationship (OR = 2.1). CONCLUSIONS: Adolescents who have experienced dating violence are more likely to exhibit a spectrum of unhealthy sexual behaviors, attitudes, beliefs, and norms.

Psychosocial correlates of adolescents' worry about STD versus HIV infection: similarities and differences.

BACKGROUND: Adolescents' worry (perceived threat) of sexually transmitted diseases (STDs) and HIV infection may have different correlates. This study examined associations between selected psychosocial and behavioral constructs and adolescents' worry about STD and HIV infection. GOAL: To assess levels and correlates of worry about STD and HIV among a high-risk sample of black adolescent females. STUDY DESIGN: High-risk black females (n = 522), enrolled in a randomized, controlled HIV and STD prevention trial, completed a questionnaire and structured interview at baseline. Worry about STD and HIV infection, recent risk behaviors, and several measures potentially related to worry were assessed. RESULTS: Levels of worry for both STD and HIV were low. Recent history of STD infection was associated with STD worry (OR, 4.6) and HIV worry (OR, 2.0). Infrequent communication about sex (OR, 2.0) and low perceived ability to negotiate condom use (OR, 2.0) were related to STD worry; whereas, only partner-specific barriers were related to HIV worry (OR, 1.9). CONCLUSIONS: Despite high risk, adolescents were generally complacent about the threat of infection with STD and HIV. Adolescents' worry about STD and HIV infection had different sets of correlates.

Socioeconomic status and self-reported gonorrhea among African American female adolescents.

BACKGROUND: Socioeconomic status is often used to explain race differences in sexually transmitted diseases (STDs), yet the independent association of socioeconomic status and STDs among adolescents has been understudied. OBJECTIVE: To examine the associations between socioeconomic status and self-reported gonorrhea among black female adolescents, after controlling for sexual risk behaviors. METHODS: Interviews and surveys were completed by 522 sexually active black adolescent females residing in low-income urban neighborhoods. RESULTS: Adolescents whose parents were unemployed were more than twice as likely to report a history of gonorrhea, compared with those with employed parents. Adolescents living with two parents were less likely to report a history of gonorrhea. CONCLUSIONS: The results of this study indicate that gonorrhea is associated with low socioeconomic status among black adolescent females regardless of the level of sexual risk behaviors. Lower socioeconomic status may be an marker for risky sociosexual environments.

Potential role for the BLM helicase in recombinational repair via a conserved interaction with RAD51.

Bloom's syndrome (BS) is an autosomal recessive disorder that predisposes individuals to a wide range of cancers. The gene mutated in BS, BLM, encodes a member of the RecQ family of DNA helicases. The precise role played by these enzymes in the cell remains to be determined. However, genome-wide hyper-recombination is a feature of many RecQ helicase-deficient cells. In eukaryotes, a central step in homologous recombination is catalyzed by the RAD51 protein. In response to agents that induce DNA double-strand breaks, RAD51 accumulates in nuclear foci that are thought to correspond to sites of recombinational repair. Here, we report that purified BLM and human RAD51 interact in vitro and in vivo, and that residues in the N- and C-terminal domains of BLM can independently mediate this interaction. Consistent with these observations, BLM localizes to a subset of RAD51 nuclear foci in normal human cells. Moreover, the number of BLM foci and the extent to which BLM and RAD51 foci co-localize increase in response to ionizing radiation. Nevertheless, the formation of RAD51 foci does not require functional BLM. Indeed, in untreated BS cells, an abnormally high proportion of the cells contain RAD51 nuclear foci. Exogenous expression of BLM markedly reduces the fraction of cells containing RAD51 foci. The interaction between BLM and RAD51 appears to have been evolutionarily conserved since the C-terminal domain of Sgs1, the Saccharomyces cerevisiae homologue of BLM, interacts with yeast Rad51. Furthermore, genetic analysis reveals that the SGS1 and RAD51 genes are epistatic indicating that they operate in a common pathway. Potential roles for BLM in the RAD51 recombinational repair pathway are discussed.

Children's sexual play and behavior in pre-school settings: staff's perceptions, reports, and responses.

OBJECTIVES: The aims of this study were to learn about the nature, frequency, and patterns of young children's observed sexual play and behavior in pre-school settings, and staff responses to them. METHOD: Fifty eight staff in 11 pre-school settings were interviewed and data obtained about their recall of observed sexualized play and behaviors of children in their care. Responses were sought both to an open question and to 20 different hypothetical scenarios describing children's behaviors with a genital or sexual content. They were asked about the proportion of children observed and the frequency of the behaviors. They were also asked for their predicted responses to encountering each of these scenarios. RESULTS: Children's curiosity about genitalia, looking and limited touching were more commonly observed, and drawing or modeling of genitalia and simulating sexual intercourse were also reported. Children inserting anything into another child and oral-genital contact had only rarely been observed. Rare behaviors always caused concern and led to some intervention. Concern about the more common behaviors was related to additional factors such as frequency, manner and talk accompanying the behavior and to other information known about the child. CONCLUSIONS: The results confirm findings from studies in other countries about the reported prevalence of more and less commonly observed sexual and genitally orientated behaviors in young children. They lend justification for concerns about children showing rarely observed behaviors or showing preoccupation with genitalia and indicate the need for a search for an explanation of these behaviors when observed.