A fingernail clam (Sphaerium sp.) shows higher reproductive success in hypoxic waters

Low dissolved O2, or hypoxia, is becoming increasingly prevalent in aquatic habitats and is considered to be stressful for aerobic organisms. However, hypoxia also can be beneficial by decreasing cellular stress, particularly that related to free radicals. Therefore, an animal’s ideal habitat may have the minimum O2 necessary to sustain aerobic metabolism, with excess O2 increasing the need to scavenge free radicals and repair free radical damage. Here we show that a natural population of small (<9 mm shell length) freshwater clams (genus Sphaerium Scopoli, 1777) lives along a dissolved O2 gradient from extreme hypoxia to moderate hypoxia. We tested the hypothesis that clams living in extreme hypoxia would have higher reproductive success than clams that live in moderate hypoxia. Clam abundance was highest in water with very low dissolved O2, conditions previously demonstrated to decrease cellular stress. The internally brooding clams reproduced year-round and had higher reproductive output in extreme hypoxia than in moderate hypoxia. The findings demonstrate that the apparent cellular-level benefits of hypoxia may translate into increased fitness, especially for small organisms.

A randomized, placebo-controlled trial (NCIC CTG MAP.2) examining the effects of exemestane on mammographic breast density, bone density, markers of bone metabolism and serum lipid levels in postmenopausal women

We hypothesized that exemestane (EXE) would reduce mammographic breast density and have unique effects on biomarkers of bone and lipid metabolism. Healthy postmenopausal women were randomized to EXE (25 mg daily) or placebo (PLAC) for 12 months and followed for a total of 24 months. The primary endpoint was change in percent breast density (PD) between the baseline and 12-month mammograms and secondary endpoints were changes in serum lipid levels, bone biomarkers, and bone mineral density (BMD). Ninety-eight women were randomized (49 to EXE; 49 to PLAC) and 65 had PD data at baseline and 12 months. Among women treated with EXE, PD was not significantly changed from baseline at 6, 12, or 24 months and was not different from PLAC. EXE was associated with significant percentage increase from baseline in N-telopeptide at 12 months compared with PLAC. No differences in percent change from baseline in BMD (lumbar spine and femoral neck) were observed between EXE and PLAC at either 12 or 24 months. Patients on EXE had a significantly larger percent decrease in total cholesterol than in the PLAC arm at 6 months and in HDL cholesterol at 3, 6, and 12 months. No significant differences in percent change in LDL or triglycerides were noted at any time point between the two treatment arms. EXE administered for 1 year to healthy postmenopausal women did not result in significant changes in mammographic density. A reversible increase in the bone resorption marker N-telopeptide without significant change in bone specific alkaline phosphatase or BMD during the 12 months treatment period and 1 year later was noted. Changes in lipid parameters on this trial were modest and reversible.

The National Cancer Institute of Canada Clinical Trials Group MAP.3 trial: an international breast cancer prevention trial

Several large phase iii trials have demonstrated that tamoxifen—and more recently, raloxifene—can effectively reduce the incidence of invasive breast cancer by 50%. However, these selective estrogen receptor modulators can also be associated with several rare, but serious, adverse events. Recently, the third-generation aromatase inhibitors (ais) have demonstrated excellent efficacy in adjuvant breast cancer trials, and they show particular promise in the breast cancer prevention setting. The National Cancer Institute of Canada Clinical Trials Group (ncic ctg) has developed a randomized phase iii study to determine the efficacy of an ai (exemestane) to reduce the incidence of invasive breast cancer in postmenopausal women at an increased risk for developing breast cancer. The ncic ctg map.3 (ExCel) trial is a double-blind placebo-controlled multicentre, multinational trial. Based on the known preclinical and clinical profile of the ais, a greater reduction in breast cancer incidence with fewer side effects is hypothesized with this class of agents than with tamoxifen or raloxifene.

Participant characteristics on an international NCIC CTG breast cancer prevention trial

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Background: Antagonizing estrogen with tamoxifen has set the precedent for preventing breast cancer. Aromatase inhibitors reduce contralateral breast cancer in the adjuvant setting more than tamoxifen. The goal of MAP.3 is to determine whether exemestane reduces invasive breast cancers in post-menopausal women at risk for the disease. Methods: NCIC CTG MAP.3 is a randomized placebo controlled double blind trial of exemestane versus placebo. Recruitment began in September 2004 in North America and Spain. Criteria for entry on MAP.3 include: a Gail score of 1.66%; previous benign breast disease including LCIS; age over 60. The target sample size for the trial is 4560. Baseline characteristics of women enrolled thus far on MAP.3 were reviewed to determine whether their projected risk of breast cancer is consistent with the assumptions made in designing the trial. Results: Baseline characteristics are available on the 1784 women enrolled to MAP.3 to date. Over 70% of participants are over 60 years old (mean 64; SD=8.2 years) and the majority of the women are Caucasian (85%). The average 5-year risk of breast cancer is 2.7% (median, 2.2%). However, a greater proportion of women over 60 (30%) have a substantially lower Gail score (<1.66) compared to women less than 60 years of age (8%). Few women in the MAP.3 cohort have been enrolled on a basis of a history of prior breast atypical hyperplasia or LCIS (8%), or DCIS treated with mastectomy (2%). Nearly half the MAP.3 participants (45%) have at least one first degree relative with malignant breast cancer, and 7.5% of these women have 2 or more first degree relatives with the disease. Conclusions: The risk profile of the women on MAP.3 will determine the event rate and therefore the time to trial unblinding and analysis. This initial description of the MAP.3 population enrolled thus far indicates a slightly lower baseline breast cancer risk in comparison to the risk profile of those enrolled in previous breast cancer prevention trials with tamoxifen or raloxifene (NSABP P1, IBIS-1 and STAR). Reasons for this difference are being explored.

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Nitric oxide stimulates insulin gene transcription in pancreatic β-cells

Recent studies have identified a positive role for nitric oxide (NO) in the regulation of pancreatic beta-cell function. The aim of this study was to determine the effects of short-term exposure to NO on beta-cell gene expression and the activity of the transcription factor PDX-1. NO stimulated the activity of the insulin gene promoter in Min6 beta-cells and endogenous insulin mRNA levels in both Min6 and isolated islets of Langerhans. Addition of wortmannin prior to NO stimulation blocked the observed increases in insulin gene promoter activity. Although NO addition stimulated the phosphorylation of p38, inhibition by SB203580 did not block the effect of NO on the insulin gene promoter. NO addition also stimulated both the nuclear accumulation and the DNA binding activity of PDX-1. This study has shown that over 24h, NO stimulates insulin gene expression, PI-3-kinase activity and the activity of the critical beta-cell transcription factor PDX-1.

Effects of rosiglitazone and metformin on pancreatic beta cell gene expression

AIMS/HYPOTHESIS

Rosiglitazone and metformin are two oral antihyperglycaemic drugs used to treat type 2 diabetes. While both drugs have been shown to improve insulin-sensitive glucose uptake, the direct effects of these drugs on pancreatic beta cells is only now beginning to be clarified. The aim of the present study was to determine the direct effects of these agents on beta cell gene expression.

METHODS

We used reporter gene analysis to examine the effects of rosiglitazone and metformin on the activity of the proinsulin and insulin promoter factor 1 (IPF1) gene promoters in the glucose-responsive mouse beta cell line Min6. Western blot and gel retardation analyses were used to examine the effects of both drugs on the regulation of IPF1 protein production, nuclear accumulation and DNA binding activity in both Min6 cells and isolated rat islets of Langerhans.

RESULTS

Over 24 h, rosiglitazone promoted the nuclear accumulation of IPF1 and forkhead homeobox A2 (FOXA2), independently of glucose concentration, and stimulated a two-fold increase in the activity of the Ipf1 gene promoter (p<0.01). Stimulation of the Ipf1 promoter by rosiglitazone was unaffected by the presence of the peroxisome proliferator activated receptor gamma antagonist GW9662. No effect of either rosiglitazone or metformin was observed on proinsulin promoter activity. Metformin stimulated IPF1 nuclear accumulation and DNA binding activity in a time-dependent manner, with maximal effects observed after 2 h.

CONCLUSIONS/INTERPRETATION

Metformin and rosiglitazone have direct effects on beta cell gene expression, suggesting that these agents may play a previously unrecognised role in the direct regulation of pancreatic beta cell function.

Otic barotrauma from air travel

Otic barotrauma occuring during air travel involves traumatic inflammation of the middle ear, caused by a pressure difference between the air in the middle ear and the external atmosphere, developing after ascent or more usually descent. The pressure difference occurs because of failure of the eustachian tube to equilibrate middle ear and atmospheric pressures. It is a common problem, presenting with ear fullness, otalgia and deafness. Severe cases may result in tympanic membrane perforation and even round window membrane rupture. Of three randomized controlled trials, one showed that oral pseudoephedrine decongestants reduced otalgia inadults with recurrent ear pain during air travel, whilst another found that oral pseudoephedrine did not decrease in-flight ear pain in children. The third trial showed that oxymetazoline decongestant nasal spray, taken 30 minutes before descent, did not produce a statistically significant reduction in symptoms of barotrauma in adults with recurrent ear pain during air travel. We review the causes, prevention and treatment of this condition.

Thickness dependence of structural relaxation in spin-cast, glassy polymer thin films

The isothermal structural relaxation of glassy, spin-cast polymer thin films has been investigated. Specifically, the thickness h of freshly cast poly(methyl methacrylate) thin films was measured over time using spectroscopic ellipsometry. The spin-cast films exhibit a gradual decrease in thickness, which is attributed to structural relaxation of the glass combined with simultaneous solvent loss. In all cases, h was found to be greater than the equilibrium thickness h(infinity) , which is obtained by cooling slowly from the melt. It is observed that both the rate of the volume relaxation and the fractional departure from h(infinity) (referred to as delta(0) ) increase with increasing film thickness. In the limit of very thin films, the initial h is close to h(infinity) , and delta(0) is small, whereas in thick films (>500 nm) , a plateau value of delta(0) of 0.16 is observed, which is close to the volume fraction of the solvent at the vitrification point. This dependence of delta(0) on thickness is observed regardless of the substrate, polymer molecular weight, or angular velocity during spin casting. Enhanced mobility near film surfaces could be leading to greater relaxation in thinner films prior to, and immediately after, the vitrification of the polymer during the deposition process.

Influence of the glass transition on solvent loss from spin-cast glassy polymer thin films

The interdependence of solvent loss and vitrification in spin-cast poly(methyl methacrylate) thin films is explored. Fast measurements of decreases in film thickness, achieved with ellipsometry, indicate that the rate of solvent (toluene) loss decreases sharply when the solvent volume fraction phi(solv) falls below about 0.15 and the film vitrifies. Ellipsometry and microgravimetry show that solvent is lost from a glassy thin film (150 nm thick) over of a period of more than ten hours, which is much longer than would be required if it was limited by diffusion in the glass. These results support the recently-proposed idea that the compression of the glass creates an energy barrier that slows down solvent loss.

Structural relaxation of spin-cast glassy polymer thin films as a possible factor in dewetting

Reiter has recently reported a situation in which the dewetting of quasi-solid films is linked to plastic deformation--rather than viscous flow--resulting from capillary forces. Herein we propose that, in thin films of some glassy polymers--especially poly(methyl methacrylate) (PMMA)--prepared by spin-casting from solvent, structural relaxation might impart sufficient stress to cause plastic deformation. We find that PMMA films decrease in thickness by several percent, which is sufficient to create significant stress in those cases in which the film is attached to a rigid substrate. The floating technique, which can take tens of minutes, might allow most of the structural relaxation to occur prior to dewetting experiments.

Assessment of an electronic daily diary in patients with overactive bladder

OBJECTIVE

To assess the effectiveness of a portable electronic diary as a data collection device for overactive bladder symptoms, and to evaluate its level of patient acceptability compared with a conventional paper-based voiding diary.

PATIENTS AND METHODS

Patients were identified through USA and UK hospital incontinence clinics. Patients were trained in the use of paper and electronic diaries before randomization, to complete either diary for 7 days. The diaries were then collected and, after a further training session, patients completed the other diary type for 7 days.

RESULTS

In all, 35 patients were recruited into the trial; overall, patients using the paper diaries (35) and electronic diaries (33) recorded similar data for the median number of incontinent episodes per week (8.2 and 7.0, respectively) and for the median number of significant leaks per day (0.4 and 0.5, respectively). However, the number of daily micturitions was slightly lower for the electronic than for the paper diary (7.3 vs 8.5, respectively). The frequency of urgency recorded in the electronic diary was higher than that recorded in the paper diary (5.8 vs 4.7). As 94% of patients found the electronic diary easy to use, and the electronic diary reflects real-time data entries, the electronic diary data may provide a more accurate reflection of patient symptoms.

CONCLUSION

We confirmed that the electronic diary is a novel method of collecting clinically relevant symptom data from patients with an overactive bladder. In addition, the ease-of-use ratings support the use of the electronic diary as a superior alternative to paper diaries, providing real-time data which can be rapidly analysed, and thus allowing a speedy review of data during ongoing clinical studies.

A comparison of physician and patient perception of the problems of habitual snoring

Assumptions are often made by doctors about the nature of the impact of uncomplicated snoring. The aim of this study was to provide a comprehensive view of the problems experienced by snoring patients, and to compare these with the perceptions of otolaryngologists. Part 1: 121 snorers and 419 otolaryngologists completed open-ended problems lists; Part 2: 56 snorers and 63 matched controls completed a mood questionnaire and the Golombok Rust Inventory of Marital State (GRIMS.) There was a clear agreement between snorers and otolaryngologists that sleep-related difficulties comprise the most frequent category of problems that may result from snoring. Snorers report a significantly greater number of physical problems and significantly fewer relationship problems than perceived by otolaryngologists. GRIMS scores were similar in patients and controls. Snorers, however, were significantly more depressed. Doctors appear to address snoring from the twin perspectives of damaged relationships and possible sleep apnoea. Their patients are more concerned about disturbing the sleep of others, and are subject to low mood. The snorers' 25 different responses are now being used as the basis for a Snoring Symptom Index.

The 1999 Helene Fuld Health Trust Fellowship. Promoting leadership development in undergraduate nursing students

In 1999, based on the recommendation of The Conservation Company. The Helene Fuld Health Trust selected New York University's Robert F. Wagner Graduate School of Public Service, in partnership with the Division of Nursing in the School of Education, to restructure its fellowship program for undergraduate nursing students. Bringing together an interdisciplinary team with experience in leadership development, nursing and health policy, and health care administration, NYU designed and delivered an innovative and state-of-the-art leadership development program for the 1999 Fuld Fellowship program. The new program started in June 1999 with 21 nursing students from all over the country. This article describes the goals and methods of the program; it also discusses early observations of the program's success that could be relevant to nursing education.

The Drosophila Geminin homolog: roles for Geminin in limiting DNA replication, in anaphase and in neurogenesis

We have identified a Drosophila homolog of the DNA replication initiation inhibitor Geminin (Dm geminin) and show that it has all of the properties of Xenopus and human Geminin. During Drosophila development, Dm Geminin is present in cycling cells; protein accumulates during S phase and is degraded at the metaphase to anaphase transition. Overexpression of Dm geminin in embryos inhibits DNA replication, but cells enter mitosis arresting in metaphase, as in dup (cdt1) mutants, and undergo apoptosis. Overexpression of Dm Geminin also induces ectopic neural differentiation. Dm geminin mutant embryos exhibit anaphase defects at cycle 16 and increased numbers of S phase cells later in embryogenesis. In a partially female-sterile Dm geminin mutant, excessive DNA amplification in the ovarian follicle cells is observed. Our data suggest roles for Dm Geminin in limiting DNA replication, in anaphase and in neural differentiation.