Measurement of the neutron radius of 208Pb through parity violation in electron scattering

We report the first measurement of the parity-violating asymmetry A(PV) in the elastic scattering of polarized electrons from 208Pb. A(PV) is sensitive to the radius of the neutron distribution (R(n)). The result A(PV)=0.656±0.060(stat)±0.014(syst) ppm corresponds to a difference between the radii of the neutron and proton distributions R(n)-R(p)=0.33(-0.18)(+0.16) fm and provides the first electroweak observation of the neutron skin which is expected in a heavy, neutron-rich nucleus.

Search for a new gauge boson in electron-nucleus fixed-target scattering by the APEX experiment

We present a search at the Jefferson Laboratory for new forces mediated by sub-GeV vector bosons with weak coupling α' to electrons. Such a particle A' can be produced in electron-nucleus fixed-target scattering and then decay to an e + e- pair, producing a narrow resonance in the QED trident spectrum. Using APEX test run data, we searched in the mass range 175-250 MeV, found no evidence for an A'→ e+ e- reaction, and set an upper limit of α'/α ~/= 10(-6). Our findings demonstrate that fixed-target searches can explore a new, wide, and important range of masses and couplings for sub-GeV forces.

Search for effects beyond the born approximation in polarization transfer observables in e(over→)p elastic scattering

Intensive theoretical and experimental efforts over the past decade have aimed at explaining the discrepancy between data for the proton electric to magnetic form factor ratio, G(E)/G(M), obtained separately from cross section and polarization transfer measurements. One possible explanation for this difference is a two-photon-exchange contribution. In an effort to search for effects beyond the one-photon-exchange or Born approximation, we report measurements of polarization transfer observables in the elastic H(e[over →],e(')p[over →]) reaction for three different beam energies at a Q(2)=2.5  GeV(2), spanning a wide range of the kinematic parameter ε. The ratio R, which equals μ(p)G(E)/G(M) in the Born approximation, is found to be independent of ε at the 1.5% level. The ε dependence of the longitudinal polarization transfer component P(ℓ) shows an enhancement of (2.3±0.6)% relative to the Born approximation at large ε.

Recoil polarization measurements of the proton electromagnetic form factor ratio to Q2 = 8.5 GeV2

Among the most fundamental observables of nucleon structure, electromagnetic form factors are a crucial benchmark for modern calculations describing the strong interaction dynamics of the nucleon's quark constituents; indeed, recent proton data have attracted intense theoretical interest. In this Letter, we report new measurements of the proton electromagnetic form factor ratio using the recoil polarization method, at momentum transfers Q2=5.2, 6.7, and 8.5  GeV2. By extending the range of Q2 for which G(E)(p) is accurately determined by more than 50%, these measurements will provide significant constraints on models of nucleon structure in the nonperturbative regime.

Physiological fluctuation of (99m)Tc-sestamibi uptake in normal mammary glands: a systematic investigation in female rats

BACKGROUND

Scintimammography is an imaging tool for the diagnosis and management of primary breast tumors. There remains a significant knowledge gap regarding the physiological fluctuations in the basal level of (99m)Tc-sestamibi uptake in normal mammary tissues with respect to the female reproductive cycle.

PURPOSE

To systematically characterize (99m)Tc-sestamibi uptake in normal mammary tissues in female Sprague Dawley (SD) rats in different estrous phases.

MATERIAL AND METHODS

The exact phase of the reproductive cycle was determined in 18 female SD rats. Each rat was sacrificed at 20 min after (99m)Tc-sestamibi injection (14.8 MBq/kg). The mammary glands were dissected, and the radioactivity uptake was measured by gamma counting.

RESULTS

Tc-99m-sestamibi uptake oscillates by about twofold and reaches a maximum at the proestrous phase of the rat reproductive cycle.

CONCLUSION

Tc-99m-sestamibi uptake fluctuates significantly in normal mammary tissues in synchrony with the female reproductive cycle, and peaks in the proestrous phase in rats, which is equivalent to the early to mid-follicular phase in the human menstrual cycle. This finding will likely benefit the detection of breast lesions that may otherwise be obscured by fluctuating background signals in surrounding normal breast tissues.

Effect of ezetimibe/simvastatin compared with atorvastatin on lipoprotein subclasses in patients with type 2 diabetes and hypercholesterolaemia

AIM

To evaluate the effects of the usual starting and next higher doses of ezetimibe/simvastatin and atorvastatin on the cholesterol content of lipoprotein subclasses in patients with type 2 diabetes and hypercholesterolaemia.

METHODS

This post hoc analysis compared the effects of treatment with ezetimibe/simvastatin 10/20 mg vs. atorvastatin 10 and 20 mg/day and ezetimibe/simvastatin 10/40 mg/day vs. atorvastatin 40 mg/day on the cholesterol content of lipoprotein subclasses in the modified intent-to-treat (mITT) population (n = 1013) and in subgroups of patients with triglyceride (TG) levels <200 mg/dl (n = 600) and >or=200 mg/dl (2.6 mmol/l) (n = 413).

RESULTS

Ezetimibe/simvastatin significantly reduced low-density lipoprotein cholesterol (LDL-C) subclasses LDL(1)-C, LDL(2)-C and LDL(3)-C; real LDL-C (LDL-C(r)); intermediate-density lipoprotein cholesterol (IDL-C), IDL(1)-C, IDL(2)-C; very low-density lipoprotein cholesterol (VLDL-C), VLDL(3)-C; and remnant-like lipoprotein cholesterol (RLP-C) from baseline more than atorvastatin at all dose comparisons (p < 0.01) in the mITT population. Significant improvements were also observed in high-density lipoprotein cholesterol (HDL-C) subclass HDL(3)-C at the ezetimibe/simvastatin 10/20 mg vs. atorvastatin 20 mg and highest dose comparisons (p < 0.001) and in VLDL(1 + 2)-C at the lowest and highest dose comparisons (p < 0.001). Changes in LDL(4)-C and LDL-C subclass patterns (A, B and I) were comparable for both treatments. Generally, similar results were observed for patients with TG levels <200 and >or=200 mg/dl (2.3 mmol). For both treatments, notable differences between TG subgroups were that patients with elevated TGs had smaller reductions in LDL(2)-C, slightly smaller decreases in all IDL subclasses and greater decreases in all VLDL-C subclasses than those with lower TG levels. Frequency of pattern B was also reduced more in patients with higher TGs for both treatments.

CONCLUSIONS

Ezetimibe/simvastatin reduced the cholesterol content of most lipoprotein subclasses from baseline with generally similar efficacy in patients with low and high TGs. Despite the different mechanism of action of ezetimibe, the response to ezetimibe/simvastatin and atorvastatin treatment related to these lipoprotein subclasses was generally consistent with the overall effects of these therapies on the major lipid/lipoprotein classes. The clinical significance of these results awaits further study.

B-cell function and islet cell and other organ-specific autoantibodies in relatives to insulin-dependent diabetic patients

The pancreatic B-cell function (glucose tolerance, C-peptide release) and organ-specific autoantibodies, including islet cell cytoplasmic and cell surface (mouse), were studied in 45 first-degree relatives of patients with insulin-dependent diabetes mellitus diagnosed before the age of 30 years. Compared to 107 healthy persons without any family history of either insulin-dependent or non-insulin-dependent diabetes mellitus, the prevalence of autoantibodies was increased among the relatives. The prevalence of islet cell antibodies did not differ between relatives and controls and none of the individuals had complement-fixing islet cell antibodies. There was no difference in glucose tolerance or C-peptide release between relatives and controls, whether they had autoantibodies or not. At a three-year follow-up, none of the individuals had developed insulin-dependent diabetes.

Neuronal migration defect: a case of subcortical heterotopia in a California sea lion

A 2 and a half-year-old male California sea lion (Zalophus californianus) presented with a history of intermittent generalized seizures. Magnetic resonance imaging revealed a large focal mass occupying the right cerebral hemisphere with moderate dilatation of the contralateral lateral ventricle. At necropsy, the right cerebral hemispheric white matter was expanded by numerous irregularly shaped, pale pink nodules up to 10 mm in diameter. The overlying cortex was characterized by increased numbers of small, poorly developed gyri with shallow, often indistinct, sulci (polymicrogyria). Microscopically, nodules were composed of neurons, oligodendroglia, microglia, and supporting neuropil and were well delineated from the surrounding white matter. The gross, histological, and immunohistochemical features of this lesion are consistent with a neuronal migration defect resulting in unilateral subcortical heterotopia.

Developing and testing an intervention to prevent homelessness among individuals discharged from psychiatric wards to shelters and 'No Fixed Address'

Shelter data in a recent study revealed discharges from psychiatric facilities to shelters or the street occurred at least 194 times in 2002 in London, Ontario, Canada. This problem must be addressed to reduce the disastrous effects of such discharge, including re-hospitalization and prolonged homelessness. An intervention was developed and tested to prevent homelessness associated with discharge directly to no fixed address. A total of 14 participants at-risk of being discharged without housing were enrolled, with half randomized into the intervention group. The intervention group was provided with immediate assistance in accessing housing and assistance in paying their first and last month's rent. The control group received usual care. Data was collected from participants prior to discharge, at 31 and 6-months post-discharge. All the individuals in the intervention group maintained housing after 3 and 6 months. All but one individual in the control group remained homeless after 3 and 6 months. The exception joined the sex trade to avoid homelessness. The results of this pilot were so dramatic that randomizing to the control group was discontinued. Discussions are underway to routinely implement the intervention. Systemic improvements can prevent homelessness for individuals being discharged from psychiatric wards.

Perceptions of health and health service utilization among homeless and housed psychiatric consumer/survivors

Homelessness has a direct impact on health. Homeless individuals report several barriers to accessing health care. Although research exists regarding the utilization of health services for homeless and housed psychiatric consumer/survivors, few studies have compared the perceived health and service utilization of these two groups. The objective of this study was to determine whether or not differences exist between the utilization of health services and the perceptions of health of homeless and housed psychiatric consumer/survivors in London, Ontario, Canada. It was hypothesized that differences would exist between homeless and housed psychiatric consumer/survivors on all health-related variables examined. A secondary analysis of quantitative data was conducted in a Community-University Research Alliance on Mental Health and Housing project funded by the Social Sciences and Humanities Research Council of Canada. Key findings include significant differences in the characteristics of each population, the use of health services and their perceptions of health. Implications for practice and policy are discussed.

Medium- and long-term outcome of laparoscopic redo fundoplication

BACKGROUND

For a small subset of patients, laparoscopic fundoplication fails, typically resulting in recurrent reflux or severe dysphagia. Although redo fundoplications can be performed laparoscopically, few studies have examined their long-term efficacy.

METHODS

Using a prospectively maintained database, the authors identified and contacted 41 patients who had undergone redo laparoscopic fundoplications at the University of Washington between 1996 and 2001. The median follow-up period was 50 months (range, 20-95 months). Current symptoms were compared with those acquired and entered into the authors' database preoperatively. Patients also were asked to return for esophageal manometry and pH testing.

RESULTS

All redo fundoplications were performed laparoscopically. There were no conversions. The most common indication for redo fundoplication was recurrent reflux. The most common anatomic abnormality was a herniated wrap. Heartburn improved in 61%, regurgitation in 69%, and dysphagia in 74% of the patients. Complete resolution of these symptoms was achieved, respectively, in 45%, 41% and 38% of these same patients. Overall, 68% of the patients rated the success of the procedure as either "excellent" or "good," and 78% said they were happy they chose to have it. For those who underwent reoperation for gastroesophageal reflux disease, distal esophageal acid exposure according to 24-h pH monitoring decreased after redo fundoplication from 15.7% +/- 18.1% to 3.4% +/- 3.6% (p = 0.041).

CONCLUSION

Although not as successful as primary fundoplication, a majority of patients can expect durable improvement in their symptoms with a laparoscopic redo fundoplication.

Large Q fever outbreak due to sheep farming near residential areas, Germany, 2005

In June 2005 Coxiella burnetii-infected sheep, grazing and lambing on a meadow bordering a residential area, caused a large Q fever outbreak (331 cases) in Germany. Our outbreak investigation provided attack rates (AR) by distance between residence and meadow, sex and age groups. The AR of people living within 50 m of the meadow was 11.8%. It decreased the further the residence was from the meadow, falling to 1.3% at 350-400 m distance (RR 8.7, 95% CI 4.5-17.1). The AR was higher in men (RR 1.4, 95% CI 1.1-1.8). In the 25-64 years age group, the AR was 2.3 times higher compared to other age groups (95% CI 1.7-3.0). The distance-related AR showed a relationship between risk of infection and living close to the meadow. Ongoing urbanization will probably lead to further Q fever outbreaks, hence prevention activities undertaken by animal and public health practitioners should be aligned and strengthened.

Reduction of Maternal Adrenal Steroids Results in Increased VEGF Protein Without Increased eNOS in the Ovine Placenta

Fetal sheep studies have shown that reduced maternal cortisol or aldosterone levels alter placental morphology, with a reduction in placental blood flow. We have now tested the hypothesis that changes in placental morphology with relative adrenal hypoadrenalism are associated with changes in vascular endothelial growth factor (VEGF) and endothelial nitric oxide synthase (eNOS). Four groups of late gestation pregnant ewes with singleton fetuses were studied; controls (intact adrenals), normal cortisol and aldosterone (ewes adrenalectomized and replaced with normal cortisol and aldosterone levels), low cortisol (ewes adrenalectomized and replaced with low cortisol levels), and low aldosterone (ewes adrenalectomized and replaced with low aldosterone levels). The placenta was categorized into A, B, C or D type placentomes. There were significantly more B and C type placentomes in the adrenalectomized groups than in controls. Overall, B types had more VEGF mRNA than A types. VEGF protein levels corresponding to a 23 kDa band were highest in low aldosterone animals in A and C type placentomes. VEGF protein levels corresponding to a 47 kDa band were higher in C type placentomes than A types; protein levels were also higher overall in low cortisol animals compared to controls. Fetoplacental eNOS protein levels were lower in the adrenalectomized groups than in controls. In conclusion, our results indicate that increases in cotyledonary VEGF(164) protein were associated with fetal tissue overgrowth in the placenta when the pregnancy-induced increase in adrenal steroids was prevented in the ewe. However, cotyledonary eNOS protein was suppressed with reduced maternal adrenal steroids, which is consistent with the reduced placental perfusion previously observed in this model.

Genetic characterization, pathogenicity, and protection studies with an avian adenovirus isolate associated with inclusion body hepatitis

An avian adenovirus (AAV) was isolated from liver samples of two 2-wk-old broiler-breeder flocks obtained from grandparents vaccinated at 10 and 17 wks of age with an autogenous inactivated vaccine containing the European AAV 8 (8565 strain) and 11 (1047 strain) serotypes (AAV8/11 vaccine). Affected broiler-breeders exhibited clinical signs and macroscopic and microscopic lesions associated with inclusion body hepatitis (IBH). The isolated adenovirus, identified as Stanford, was molecularly characterized as European serotype 9. The pathogenicity of the Stanford strain was confirmed after inoculation of specific-pathogen-free (SPF) chickens at 1-7 days of age, causing 100% and 20% mortality, respectively. The level of protection against IBH was evaluated in two broiler-breeder progenies from AAV 8/11-vaccinated grandparent flocks and a commercial broiler flock by challenge at 1 or 7 days of age with the AAV 8 and 11 serotypes and/or the Stanford strain. The broiler-breeder progenies and the commercial broiler flock exhibited protection against IBH after challenge. No significant differences in mean body weights were observed at 3 wk of age in any of the evaluated groups. We conclude that broiler-breeder progenies from 30- to 50-wk-old grandparents vaccinated with the AAV 8/11 vaccine were adequately protected against challenge with the AAV 8 and 11 serotypes and the Stanford strain.