Optical imaging of orientation and ocular dominance maps in area 17 of cats with convergent strabismus

Strabismus (or squint) is both a well-established model for developmental plasticity of the brain and a frequent clinical symptom. While the layout and topographic relationship of functional domains in area 17 of divergently squinting cats has been analyzed extensively in recent years (e.g. L?wel et al., 1998), functional maps in convergently squinting animals have so far not been visualized with comparable detail. We have therefore investigated the functional organization of area 17 in adult cats with a surgically induced convergent squint angle. In these animals, visual acuity was determined by both behavioral tests and recordings of visual evoked potentials, and animals with comparable acuities in both eyes were selected for further experiments. The functional layout of area 17 was visualized using optical imaging of intrinsic signals. Monocular iso-orientation domains had a patchy appearance and their layout was different for left and right eye stimulation, so that segregated ocular dominance domains could be visualized. Iso-orientation domains exhibited a pinwheel-like organization, as previously described for normal and divergently squinting cats. Mean pinwheel density was the same in the experimental and control animals (3.4 pinwheel centers per mm2 cortical surface), but significantly (P < 0.00001) higher than that reported previously for normal and divergently squinting cats (2.7/mm2). A comparison of orientation with ocular dominance maps revealed that iso-orientation domains were continuous across the borders of ocular dominance domains and tended to intersect these borders at steep angles. However, in contrast to previous reports in normally raised cats, orientation pinwheel centers showed no consistent topographical relationship to the peaks of ocular dominance domains. Taken together, these observations indicate an overall similarity between the functional layout of orientation and ocular dominance maps in area 17 of convergently and divergently squinting cats. The higher pinwheel densities compared with previous reports suggest that animals from different gene pools might generally differ in this parameter and therefore also in the space constants of their cortical orientation maps.     

Effect of bremazocine,a kappa-opioid receptor agonist,on inositol phosphate formation in isolated iris-ciliary bodies

The goal of the current study was to examine the effect of the kappa-opioid agonist, bremazocine (BRE), on inositol phosphate (IP) formation in the rabbit iris-ciliary body (ICB). Concentrations of BRE (10(-7) to 10(-5) M) augmented levels of IP. Incubation of ICBs with BRE (10(-6) M) produced a time-dependent increase in IP levels that peaked at 60 s and declined to basal levels by 5 min. The increase in IP levels produced by BRE (10(-6) M) was inhibited by the kappa-opioid receptor antagonist, nor-binaltorphimine (nor-BNI, 10(-7) to 10(-5) M) and by activation of PKC with PDBu (10(-7) M). These results demonstrate that kappa-opioid receptor activation by BRE in the rabbit ICB is linked to IP production. Thus, opioid agonist-induced increases in IP activity could play a role in BRE-induced increases in atrial natriuretic peptide release and alterations in aqueous humor dynamics.     

Determinants of occupational disability following a low back injury: a critical review of the literature

The aim of this research was to determine prognostic indicators of work disability in occupational back pain as reported in the literature, by systematically searching the research literature, assessing the methodological quality of the research, and synthesizing the findings into a concise summary. An article was considered eligible for review if research participants had an injury of the back, the article was based on original research, published in English, and involved a cohort with back pain less than 6 months post injury with at least one follow up assessment. Each article was independently reviewed by two blinded reviewers using 19 appraisal criteria for methodological quality of prognostic studies. Nineteen studies met the methodological standard to be included. Time since onset, demographic factors, functional disability, psychological distress, pain reports, previous episodes, and work environment were identified as important prognostic factors. Most studies compartmentalized the factors they considered. What is needed is a comprehensive multivariate biopsychosocial job-related model of work disability.     

Patients' access to their online electronic health records

We surveyed a randomized group of 1050 adult patients stratified for age and sex, from a general practice in Oxfordshire, to find out their attitudes to electronic health records (EHRs). Eighty-six per cent thought that patients should have the right to see their records. While 72% knew that they had the right to see their records, only 4% had done so. Private EHR viewing booths with a computer and fingerprint identification system were installed in the primary care centre. Patients were randomly selected from those who responded to the questionnaire and wished to view their EHR. Of the 100 patients who saw their online EHR, 99 found the session useful and 84 found their records easy to understand. Three focus groups were held with 14 patients who said that they did not want to access their EHRs. The reasons patients gave during the focus groups included that they trusted their general practitioner and thought it would imply a lack of confidence. After the focus groups, 11 patients changed their minds and accessed their records. We believe that patient-accessed EHRs will offer substantial benefits to patients, health professionals and the National Health Service as a whole.     

Potential role of increased iron stores in diabetes

Diabetes mellitus (DM) is an important risk factor for the development of cardiovascular disease. Extensive clinical, epidemiologic, and basic studies suggest that excessive tissue iron stores may contribute to the occurrence and complications of DM. Secondary diabetes occurs in inherited pathologic iron overload syndromes of European- and African-derived populations and is an established complication of transfusional iron overload. Epidemiologic studies have repeatedly shown positive correlation between levels of serum ferritin and those of fasting glucose, insulin, and glycosylated hemoglobin. Iron reduction therapy in hereditary hemochromatosis and transfusional iron overload is associated with improved glucose tolerance and reduced incidence of secondary diabetes. Trials of iron reduction therapy in diabetes mellitus, although limited and inconclusive, have shown clinical improvement in some patients. The current article reviews evidence suggesting that tissue iron contributes to DM and its complications and presents preliminary data that emphasize the potential importance of iron overload in DM of African Americans.     

Role of the psychiatrist in the care of patients with hepatitis C and HIV/AIDS

Hepatitis C and HIV/AIDS are among the most significant infectious diseases of our time. Psychiatric patients are often part of the higher risk population to contract these diseases, and patients who have contracted these diseases experience a wide variety of psychiatric problems associated with the underlying infection and with its treatment. The authors provide an overview of these infectious diseases and then describe the varying roles psychiatrists have in caring for these patients in the various settings of their work. The complexity of these patients presents a unique challenge to, and opportunity for, psychiatrists to integrate and coordinate their interventions with those of other medical providers and thereby enhance the patient's cooperation with all aspects of care.     

Targeted mass treatment for syphilis with oral azithromycin

From mid 1997 to end of 1999, there was a sexually-transmitted infectious syphilis outbreak mainly in heterosexual people in British Columbia, Canada, that was concentrated in Vancouver. The rate across the province increased from less than 0.5 to 3.4 per 100000, and the rate in Vancouver reached 12.9 per 100000. We aimed to eliminate the syphillis outbreak by treating people at risk of infection. In 2000, a targeted mass treatment programme provided azithromycin (1.8 g orally) to 4384 at-risk residents in this city. After the programme, syphilis frequency fell significantly for 6 months (p=0.016), but rose again in 2001. Results from curve fitting analyses showed that the number of cases in 2001 (177) was higher than expected (0.0001相似文献   

Rapid intravenous loading of levodopa for human research: clinical results

Levodopa has several advantages as a pharmacological challenge agent for human neuroscience research. Exogenous levodopa changes striatal neuronal activity and increases extracellular dopamine concentrations, and with adequate inhibition of peripheral metabolism levodopa does not change mean cerebral blood flow. For neuroimaging studies of Parkinson disease (PD) and Tourette syndrome, we sought to rapidly produce a biologically relevant steady-state levodopa concentration and then maintain that concentration for at least an hour. We also wished to minimize side effects, even in individuals without prior levodopa treatment. We designed a two-stage intravenous infusion protocol based on published levodopa pharmacokinetic data. We report results of 125 infusions in 106 subjects, including healthy volunteers, PD patients, and people with chronic tics. At higher doses (target steady-state levodopa concentrations of 2,169 and 1,200 ng/ml), treatment-naive volunteers had unacceptably frequent side effects. The final infusion protocol, with a target steady-state concentration of 600 ng/ml, was well-tolerated (mild nausea in 11% of subjects was the only side effect occurring significantly more than in single-blind saline infusions), produced the desired plasma levodopa concentration (612+/-187 ng/ml, mean+/-S.D.), and produced statistically significant antiparkinsonian benefit (16% mean reduction in a standard rating of parkinsonian motor signs, P<0.0005).     

Early posthatch starvation induces myonuclear apoptosis in chickens

The effect of early posthatch starvation on myonuclear apoptosis was examined in chickens. Male broiler chickens were or were not provided feed for the first 3-d posthatch. Subsequently, all chickens were provided feed for an additional 4-d posthatch. Chickens were killed at 3- and 7-d posthatch, and the pectoralis thoracicus was harvested, fixed and embedded in paraffin. Muscle sections were labeled with the terminal deoxynucleotidyl transferase histochemical staining technique to identify apoptotic nuclei. At 3- and 7-d posthatch, there was a significantly (P < 0.05) smaller myofiber cross-sectional area for the starved compared with the fed chickens. A larger proportion (P < 0.05) of apoptotic nuclei relative to total nuclei was observed in the starved compared to the fed chickens killed at 3-d posthatch, but the proportion of apoptotic nuclei relative to total nuclei did not differ (P > 0.05) between the starved and fed chickens killed at 7-d posthatch. It appears that apoptosis is a mechanism contributing to the smaller myofiber size observed when feed is not provided early posthatch.