Search for gravitational waves associated with γ-ray bursts detected by the interplanetary network

We present the results of a search for gravitational waves associated with 223 γ-ray bursts (GRBs) detected by the InterPlanetary Network (IPN) in 2005-2010 during LIGO's fifth and sixth science runs and Virgo's first, second, and third science runs. The IPN satellites provide accurate times of the bursts and sky localizations that vary significantly from degree scale to hundreds of square degrees. We search for both a well-modeled binary coalescence signal, the favored progenitor model for short GRBs, and for generic, unmodeled gravitational wave bursts. Both searches use the event time and sky localization to improve the gravitational wave search sensitivity as compared to corresponding all-time, all-sky searches. We find no evidence of a gravitational wave signal associated with any of the IPN GRBs in the sample, nor do we find evidence for a population of weak gravitational wave signals associated with the GRBs. For all IPN-detected GRBs, for which a sufficient duration of quality gravitational wave data are available, we place lower bounds on the distance to the source in accordance with an optimistic assumption of gravitational wave emission energy of 10(-2)M⊙c(2) at 150 Hz, and find a median of 13 Mpc. For the 27 short-hard GRBs we place 90% confidence exclusion distances to two source models: a binary neutron star coalescence, with a median distance of 12 Mpc, or the coalescence of a neutron star and black hole, with a median distance of 22 Mpc. Finally, we combine this search with previously published results to provide a population statement for GRB searches in first-generation LIGO and Virgo gravitational wave detectors and a resulting examination of prospects for the advanced gravitational wave detectors.

Search for gravitational waves associated with γ-ray bursts detected by the interplanetary network

We present the results of a search for gravitational waves associated with 223 γ-ray bursts (GRBs) detected by the InterPlanetary Network (IPN) in 2005-2010 during LIGO's fifth and sixth science runs and Virgo's first, second, and third science runs. The IPN satellites provide accurate times of the bursts and sky localizations that vary significantly from degree scale to hundreds of square degrees. We search for both a well-modeled binary coalescence signal, the favored progenitor model for short GRBs, and for generic, unmodeled gravitational wave bursts. Both searches use the event time and sky localization to improve the gravitational wave search sensitivity as compared to corresponding all-time, all-sky searches. We find no evidence of a gravitational wave signal associated with any of the IPN GRBs in the sample, nor do we find evidence for a population of weak gravitational wave signals associated with the GRBs. For all IPN-detected GRBs, for which a sufficient duration of quality gravitational wave data are available, we place lower bounds on the distance to the source in accordance with an optimistic assumption of gravitational wave emission energy of 10(-2)M⊙c(2) at 150 Hz, and find a median of 13 Mpc. For the 27 short-hard GRBs we place 90% confidence exclusion distances to two source models: a binary neutron star coalescence, with a median distance of 12 Mpc, or the coalescence of a neutron star and black hole, with a median distance of 22 Mpc. Finally, we combine this search with previously published results to provide a population statement for GRB searches in first-generation LIGO and Virgo gravitational wave detectors and a resulting examination of prospects for the advanced gravitational wave detectors.

Feeding butter with elevated content of trans-10, cis-12 conjugated linoleic acid to lean rats does not impair glucose tolerance or muscle insulin response

Background

Numerous studies have investigated the effects of isolated CLA supplementation on glucose homeostasis in humans and rodents. However, both the amount and relative abundance of CLA isomers in supplemental form are not representative of what is consumed from natural sources. No study to date has examined the effects of altered CLA isomer content within a natural food source. Our goal was to increase the content of the insulin desensitizing CLA_t10,c12 isomer relative to the CLA_c9,t11 isomer in cow’s milk by inducing subacute rumenal acidosis (SARA), and subsequently investigate the effects of this milk fat on parameters related to glucose and insulin tolerance in rats.

Methods

We fed female rats (~2.5 to 3 months of age) CLA _t10,c12 –enriched (SARA) butter or non-SARA butter based diets for 4 weeks in either low (10% of kcal from fat; 0.18% total CLA by weight) or high (60% of kcal from fat; 0.55% total CLA by weight) amounts. In an effort to extend these findings, we then fed rats high (60% kcal) amounts of SARA or non-SARA butter for a longer duration (8 weeks) and assessed changes in whole body glucose, insulin and pyruvate tolerance in comparison to low fat and 60% lard conditions.

Results

There was a main effect for increased fasting blood glucose and insulin in SARA vs. non-SARA butter groups after 4 weeks of feeding (p < 0.05). However, blood glucose and insulin concentration, and maximal insulin-stimulated glucose uptake in skeletal muscle were similar in all groups. Following 8 weeks of feeding, insulin tolerance was impaired by the SARA butter, but not glucose or pyruvate tolerance. The non-SARA butter did not impair tolerance to glucose, insulin or pyruvate.

Conclusions

This study suggests that increasing the consumption of a naturally enriched CLA_t10,c12 source, at least in rats, has minimal impact on whole body glucose tolerance or muscle specific insulin response.

IL-6 is not essential for exercise-induced increases in glucose uptake

Interleukin-6 (IL-6) increases glucose uptake in resting skeletal muscle. IL-6 is released from skeletal muscle during exercise; however; it is not known whether this IL-6 response is important for exercise-induced increases in skeletal muscle glucose uptake. We report that IL-6 knockout (KO) mice, 4 mo of age, have similar body weight to wild-type (WT), and, under resting conditions, oxygen consumption, food intake, substrate utilization, glucose tolerance, and insulin sensitivity are not different. Maximal exercise capacity is also similar to WT. We investigated substrate utilization and glucose clearance in vivo during steady-state treadmill running at 70% of maximal running speed and found that WT and IL-6 KO mice had similar rates of substrate utilization, muscle glucose clearance, and phosphorylation of AMP-activated protein kinase T172. These data provide evidence that IL-6 does not play a major role in regulating substrate utilization or skeletal muscle glucose uptake during steady-state endurance exercise.

Exercise restores insulin, but not adiponectin, response in skeletal muscle of high-fat fed rodents

High-fat (HF) diets impair skeletal muscle response to the insulin-sensitizing adipokine adiponectin (Ad) in rodents, preceding the development of insulin resistance. Skeletal muscle insulin response in HF-fed rats can be restored with chronic exercise; whether recovery of skeletal muscle Ad response is necessary for the exercise-induced recovery of insulin-stimulated glucose transport is not known. In the current study, insulin and Ad resistance were induced in rodents with 4 wk of HF feeding (HF4; low-fat fed animals used as control). Rats were then treadmill-exercised (HF5EX1, HF6EX2) or supplemented orally with the pharmacological agent β-guadinoproprionic acid (GPA; HF5GPA1, HF6GPA2) for 1 or 2 wk with continued HF feeding. Insulin and Ad responses (glucose transport and palmitate oxidation, respectively) were assessed 48 h after the last exercise bout ex vivo in isolated solei. Insulin response was impaired following 4 wk of HF feeding and improved with 1 and 2 wk of exercise and β-GPA supplementation (HF5EX1, HF6EX2, HF5GPA1, and HF6GPA2). The recovery of insulin response generally coincided with improved Akt Thr308 phosphorylation in HF5GPA1, HF6EX2, and HF6GPA2, although not in HF5EX1. Ad-stimulated palmitate oxidation was not restored with either treatment. Total protein contents of AdipoR1, AdipoR2, APPL1, and APPL2, as well as total and phosphorylated AMPK and ACC were unaltered by diet, exercise, and β-GPA at the assessed time points. We conclude that the exercise and pharmacologically (β-GPA)-induced recovery of skeletal muscle insulin response after HF feeding is not dependent on the restoration of Ad response, as assessed ex vivo.

What do children with cancer know about their medications?

Objective

To explore the health literacy of children diagnosed with Acute Lymphoblastic Leukemia (ALL) through their knowledge of their medications.

Methods

Within the Basic Interpretive approach to qualitative research, semi-structured interviews were conducted with children from ages 6 to18 years (n=16) between May and September 2009 to determine their knowledge of medication properties, medication habits and medication teaching. REB approval was obtained.

Results

The younger children (mean age 7.5 years) correctly answered, on average, 51% of the questions on colour, 26% of the questions on name, 25% of the questions on frequency, and 8% of the questions on the purposes of their medications. The older children (mean age 16 years) scored at least 35% higher for each characteristic. All of the younger children reported that physicians consistently directed medication education to parents only, and that the younger children were rarely present during these sessions. 13 of the 16 children stated that they want to learn more about and be more involved in education sessions addressing their medications.

Conclusions

Children with ALL at the IWK Health Centre do not have a good knowledge of their medications, however most children expressed that they want to know more about their medications.

The effects of KT3-671, a new angiotensin II (AT 1) receptor blocker in mild to moderate hypertension

AIMS

To compare the antihypertensive effect, and tolerability and safety of once daily doses of KT3-671 with that of placebo in patients with mild to moderate uncomplicated essential hypertension.

METHODS

A randomised, multicentre, double blind, parallel-group comparison of KT3-671 with placebo. Hypertensive patients [Ambulatory Blood Pressure Monitoring (ABPM), mean daytime DBP > 90 mmHg, Office sitting mean DBP 95-114 after a 7-28 day washout period] entered a 2-week, single blind, run-in phase. Patients eligible for the double-blind phase were randomised to receive KT3-671 40 mg, 80 mg, 160 mg or placebo once daily over 4 weeks. The primary end-point was trough mean sitting office DBP. The study had 90% power to detect a 5 mmHg change between treatments and placebo at the 5% level of significance. The secondary end-points were 24 hour, daytime and night time mean ABPM.

RESULTS

Office DBP was significantly lower with KT3-671 40 mg but not the other 2 dosage groups (-3.2; 95% CL -6.1 : -0.3 P < 0.03). Office SBP was significantly reduced with all dosage groups (40 mg -5.9, 95% CL -11 : -0.9; 80 mg -4.9, 95% CL -9.9 : 0.1 and 160 mg -5.7, 95% CL -10.8 : -0.7 P < 0.05). All doses of KT3-671 reduced systolic and diastolic ABPM. The number of patients with treatment related adverse events were comparable to placebo (38.8% KT3-671 vs 32.8% placebo). There was some evidence of a dose-response relationship with fall in nocturnal ABPM.

CONCLUSIONS

Oral KT3-671 was well tolerated. KT3-671 reduced office systolic BP at all doses and diastolic BP at some of the doses. Due to greater precision and power, the falls in mean ambulatory systolic and diastolic pressure were all significantly lower than placebo.

The novel 5-lipoxygenase inhibitor ABT-761 attenuates cerebral vasospasm in a rabbit model of subarachnoid hemorrhage

OBJECTIVE

Eicosanoids have been implicated in the pathogenesis of cerebral vasospasm after subarachnoid hemorrhage (SAH). Leukotrienes, 5-hydroxyperoxyeicosatetraenoic acid, and 5-hydroxyeicosatetraenoic acid are part of this group of substances, resulting from the 5-lipoxygenase activity on arachidonic acid metabolism. This study examined the effects of ABT-761, a new 5-lipoxygenase inhibitor, on cerebral vasospasm in an in vivo rabbit model of SAH.

METHODS

A total of 48 rabbits were assigned to one of six groups: SAH + placebo (n = 8), SAH + ABT-761 20 mg/kg (n = 8), SAH + ABT-761 30 mg/kg (n = 8), control + placebo (n = 8), control + ABT-761 20 mg/kg (n = 8), and control + ABT-761 30 mg/kg (n = 8). Drug administration was initiated 30 minutes after induction of SAH and repeated 24 hours later. The animals were killed 48 hours after SAH, using the perfusion-fixation method. The cross sectional areas of basilar artery histological sections were measured by an investigator blinded to the treatment groups of the individual samples.

RESULTS

In placebo-treated animals, the average luminal cross sectional area of the basilar artery was reduced by 68% after SAH as compared with controls (P < 0.0001). After SAH, the vasospastic response was attenuated in animals treated with 20 or 30 mg/kg representing a 28 or 35% reduction, respectively (P = 0.0011 and P = 0.0038).

CONCLUSION

The results demonstrated that ABT-761 is effective in attenuating experimental cerebral vasospasm, indicating that this new drug represents a potential therapeutic agent for the treatment of vasospasm after SAH.

The ascertainment and management of tuberculosis in Tayside, Scotland during 1993-94

OBJECTIVE

To evaluate whether utilising a database of dispensed prescriptions for anti-tuberculous chemotherapy could improve case ascertainment compared to standard methods. A further objective was to assess whether cases were managed according to standard guidelines.

DESIGN

Retrospective case note audit.

SETTING

Tayside, Scotland

SUBJECTS

Patients identified by conventional (i.e. SMRI diagnostic codes, notifications to the Health Board, microbiology and pathology reports) and the data base (MEMO) as potentially having tuberculosis and receiving treatment between 1st January 1993 and 31st December 1994. One hundred and ninety one potential cases were identified. One hundred and twenty two case notes were obtained for review. Eighty eight of these were initially thought to have tuberculosis and the results below refer to these 88 cases.

RESULTS

MEMO identified 43 cases not found by conventional methods. Cases identified by MEMO were more likely to have been managed as outpatients and less likely to have positive microbiology than cases identified by conventional means. Only 26 cases were notified to the Health Board, including all smear positive cases.

CONCLUSIONS

Notification of tuberculosis continues to be incomplete. Use of the MEMO system almost doubled case ascertainment. The absence of a firm diagnosis may lead to a reluctance to notify cases being treated as tuberculosis.

Parallel expression of macrophage metalloelastase (MMP-12) in duodenal and skin lesions of patients with dermatitis herpetiformis

BACKGROUND

Dermatitis herpetiformis (DH) is a specific dermatological manifestation of coeliac disease and 80% of DH patients have gluten sensitive enteropathy manifested by crypt hyperplasia and villous atrophy. Matrix degradation mediated by collagenase 1 (MMP-1) and stromelysin 1 (MMP-3) has previously been implicated in the pathobiology of coeliac intestine and cutaneous DH blisters.

AIMS

To study expression of stromelysin 2, metalloelastase, collagenase 3, and matrilysin in the intestine and skin of DH patients.

METHODS

In situ hybridisation using 35S labelled cRNA probes was performed on duodenal biopsies of 15 DH patients, three samples each of control duodenal or jejunal mucosa, fetal ileal explants, lesional DH skin, and 19 serial biopsies of experimental DH blisters. Immunostaining was used to examine type IV collagen, macrophages (CD68), and 92 kDa gelatinase (MMP-9) in the specimens.

RESULTS

Metalloelastase (MMP-12) was abundantly expressed by subepithelial macrophages in both coeliac intestine and spontaneous and induced DH rash. It was also upregulated in the experimental model of coeliac disease (staphylococcal endotoxin B stimulated fetal explants). The only other MMP detected was MMP-9 which did not colocalise with MMP-12.

CONCLUSIONS

Upregulation of metalloelastase is associated with T cell mediated immune responses both in the intestine and skin. In addition to modulating macrophage migration, it may contribute to degradation of proteoglycans or basement membrane components in the subepithelial mucosa.

Diaspirin cross-linked Hb and norepinephrine prevent the sepsis-induced increase in critical O(2) delivery

We hypothesized that support of arterial perfusion pressure with diaspirin cross-linked Hb (DCLHb) would prevent the sepsis-induced attenuation in the systemic O(2) delivery-O(2) uptake relationship. Awake septic rats were treated with a chronic infusion of DCLHb or a reference treatment [norepinephrine (NE)] to increase mean arterial pressure by 10-20% over 18 h. Septic and sham control groups received normal saline. Isovolemic hemodilution to create anemic hypoxia was then performed in a metabolic box during continuous measurement of systemic O(2) uptake. O(2) delivery was calculated from hemodynamic variables, and the critical point of O(2) delivery (DO(2 crit)) was determined using piecewise regression analysis of the O(2) delivery-O(2) uptake relationship. Sepsis increased DO(2 crit) from 4.99 +/- 0.17 to 6.69 +/- 0.42 ml x min(-1) x 100 g(-1) (P < 0.01), while O(2) extraction capacity was decreased (P < 0.05). DCLHb and NE infusion prevented the sepsis-induced increase in DO(2 crit) [4.56 +/- 0.42 ml x min(-1) x 100 g(-1) (P < 0.01) and 5.04 +/- 0.56 ml x min(-1) x 100 g(-1) (P < 0.05), respectively]. This was explained by a 59% increase in O(2) extraction capacity in the DCLHb group compared with septic controls (P < 0.05), whereas NE treatment decreased systemic O(2) uptake in anemic hypoxia (1.51 +/- 0.08 vs. 1.87 +/- 0.1 ml x min(-1) x 100 g(-1) in septic controls, P < 0.05). We conclude that DCLHb ameliorated O(2) extraction capacity in the septic microcirculation, whereas NE decreased the metabolic demands of the tissues.

Community antibiotic therapy, hospitalization and subsequent respiratory tract isolation of Haemophilus influenzae resistant to amoxycillin: a nested case-control study

The study objective was to determine whether recent community antibiotic prescribing and hospitalization are associated with beta-lactam resistance in respiratory isolates of Haemophilus influenzae. Data obtained for hospitalization and community prescribing (in the previous 3 months) from 412 adults (>15 years) in whom an episode of respiratory tract infection had been described, during which H. influenzae was isolated, were analysed. Seventy-three (17.7%) isolates of H. influenzae were resistant to amoxycillin. Resistance was associated with recent hospitalization [odds ratio (OR) 3.2, 1.8-5.6] and antibiotic exposure in the community (2.1, 1.2-3.6). These variables were independently associated with amoxycillin resistance [hospitalization (OR 4.5, 1. 7-12.5) and community beta-lactam antibiotic exposure (3.9, 1.6-9. 8)]. Hospitalized patients probably received antibiotics during their admission although aquisition of the organism or the beta-lactamase via plasmids from other Gram-negative organisms in the hospital could also be a factor. Control measures to reduce the inappropriate use of antimicrobials in the community and in hospital need to be reinforced.

Not so simple cystitis: how should prescribers be supported to make informed decisions about the increasing prevalence of infections caused by drug-resistant bacteria?

Trimethoprim is a safe, effective, and inexpensive treatment for cystitis. However, at least 25% of bacteria isolated from urine samples in general practice are now resistant to trimethoprim in the laboratory. The relationship between laboratory resistance and clinical outcome is complex. Cephalexin appears to be more active than trimethoprim in the laboratory but has been consistently less effective in clinical trials. There is little point in collecting data about the prevalence of drug resistance in urinary bacteria unless it is linked to evidence about the impact of resistance on clinical outcomes. Pragmatic clinical trials are required to provide practices with clear thresholds for managing their antibiotic policies; for example, 'Change from trimethoprim to drug X when the probability of trimethoprim resistance reaches Y%.' Prescribers should be aware that trimethoprim resistance is most likely to occur in patients who have been exposed to trimethoprim or other antibiotics in the previous six months, and that the risk increases with age. This information could be used to stratify women according to risk of infection by trimethoprim-resistant bacteria. Health education leaflets are an effective method for reducing the frequency of recurrent cystitis. Symptomatic treatment can control symptoms and allow time for microbiological investigation. Both of these strategies may help to reduce unnecessary prescribing of antibiotics in general and quinolones in particular.