二乙酰基莲心碱对猪冠状动脉条的影响

目的:观察二乙酰基莲心碱拮抗氯化钾、乙酰胆碱(Ach)和组胺(His)所致猪冠状动脉条收缩的作用.方法:离体平滑肌实验方法,观察二乙酰基莲心碱对氯化钾,Ach,His所致猪冠状动脉条收缩曲线的影响以及在无钙克氏液中,对His引起猪冠状动脉条第一相收缩和钙引起第二相收缩的影响.结果:不同剂量二乙酰基莲心碱可使氯化钾,Ach,His所致冠脉条收缩量效曲线呈非竞争性拮抗作用,对冠脉条第一相和第二相收缩都有明显的抑制作用结论:二乙酰基莲心碱具有扩张冠脉的作用,此作用与拮抗细胞内钙的释放和抑制外钙内流有关.     

Longitudinal Changes in Muscle Mass,Muscle Strength,and Physical Performance in Acutely Hospitalized Older Adults

ObjectivesAcute hospitalization may lead to a decrease in muscle measures, but limited studies are reporting on the changes after discharge. The aim of this study was to determine longitudinal changes in muscle mass, muscle strength, and physical performance in acutely hospitalized older adults from admission up to 3 months post-discharge.DesignA prospective observational cohort study was conducted.Setting and ParticipantsThis study included 401 participants aged ≥70 years who were acutely hospitalized in 6 hospitals. All variables were assessed at hospital admission, discharge, and 1 and 3 months post-discharge.MethodsMuscle mass in kilograms was assessed by multifrequency Bio-electrical Impedance Analysis (MF-BIA) (Bodystat; Quadscan 4000) and muscle strength by handgrip strength (JAMAR). Chair stand and gait speed test were assessed as part of the Short Physical Performance Battery (SPPB). Norm values were based on the consensus statement of the European Working Group on Sarcopenia in Older People.ResultsA total of 343 acute hospitalized older adults were included in the analyses with a mean (SD) age of 79.3 (6.6) years, 49.3% were women. From admission up to 3 months post-discharge, muscle mass (?0.1 kg/m²; P = .03) decreased significantly and muscle strength (?0.5 kg; P = .08) decreased nonsignificantly. The chair stand (+0.7 points; P < .001) and gait speed test (+0.9 points; P < .001) improved significantly up to 3 months post-discharge. At 3 months post-discharge, 80%, 18%, and 43% of the older adults scored below the cutoff points for muscle mass, muscle strength, and physical performance, respectively.Conclusions and ImplicationsPhysical performance improved during and after acute hospitalization, although muscle mass decreased, and muscle strength did not change. At 3 months post-discharge, muscle mass, muscle strength, and physical performance did not reach normative levels on a population level. Further research is needed to examine the role of exercise interventions for improving muscle measures and physical performance after hospitalization.     

Anatomical connection strength predicts dopaminergic drug effects on fronto-striatal function

Rationale

The neurotransmitter dopamine plays a key role in cognitive functions that are associated with fronto-striatal circuitry and has been implicated in many neuropsychiatric disorders. However, there is a large variability in the direction and extent of dopaminergic drug effects across individuals.

Objectives

We investigated whether individual differences in dopaminergic drug effects on human fronto-striatal functioning are associated with individual differences in white matter tracts.

Methods

The effects of the dopamine receptor agonist bromocriptine were assessed using functional magnetic resonance imaging in 22 healthy volunteers in a placebo-controlled, double-blind, within-subject design. Human psychopharmacology and functional neuroimaging were combined with functional connectivity analyses and structural connectivity analyses to establish a link between dopaminergic drug effects on fronto-striatal function and fronto-striatal anatomy.

Results

We demonstrate that bromocriptine alters functional signals associated with attention switching in the basal ganglia. Crucially, individual differences in the drug’s effect on these signals could be predicted from individual differences in fronto-striato-thalamic white matter tracts, as indexed by diffusion tensor imaging. Anatomical fronto-striatal connectivity also predicted drug effects on switch-related functional connectivity between the basal ganglia and the prefrontal cortex.

Conclusions

These data reinforce the link between dopamine, cognition and the basal ganglia and have implications for the individual tailoring of dopaminergic drug therapy based on anatomical fronto-striatal connection strength.     

Social support for youth physical activity: Importance of siblings, parents, friends and school support across a segmented school day

Background  

Whilst evidence exists for the influence of encouragement on physical activity participation, the diversity of support sources and the type of physical activity examined previously is limited. This study examined the importance of perceived encouragement from parents, siblings/cousins, friends, and schools on participation levels across three time-specific activity opportunities that are available during a school day (after-school physical activities, lunchtime activity, and active transportation to and from school).     

The risk of disseminated Bacille Calmette-Guerin (BCG) disease in HIV-infected children

OBJECTIVES: Bacille Calmette-Guerin (BCG), a live attenuated Mycobacterium bovis vaccine, poses a risk to human immunodeficiency virus (HIV)-infected children; this risk has not been well quantified. We estimate the risk of disseminated BCG disease in HIV-infected children in a setting highly endemic for tuberculosis and HIV. DESIGN AND METHODS: We conducted a prospective hospital-based surveillance study in the Western Cape Province, South Africa. Clinical and laboratory-confirmed cases of disseminated BCG disease in children<1 year of age from January 2002 to December 2004 at a referral hospital were used as numerator data. Denominator data for calculations of disseminated BCG risk were obtained through estimating the total number of HIV-infected infants receiving BCG based on the known vaccination coverage in the study setting, combined with population data on the total number of children<1 year of age, the known HIV prevalence amongst women attending public antenatal care facilities and different scenarios (5-15%) for the rate of vertical HIV transmission. RESULTS: Nine cases of disseminated BCG disease were identified over the study period, seven of these were in HIV-infected infants. The estimated risk for HIV-infected infants to develop disseminated BCG disease, given a 95% BCG coverage and an HIV prevalence of 12.4-15.4% amongst women, were as follows for different scenarios of vertical HIV transmission: 329-417/100,000 vaccinees (assuming 5% vertical HIV transmission), 164-208/100,000 vaccinees (assuming 10% vertical HIV transmission) and 110-139/100,000 vaccinees (assuming 15% vertical HIV transmission). CONCLUSIONS: The risk of disseminated BCG disease is increased several hundred fold in HIV-infected infants compared to the documented risk in HIV-uninfected infants. Data on the protective effect of BCG in HIV-exposed and infected children is lacking. Population- and hospital-based surveillance is vitally important to more accurately estimate the safety and benefits of BCG in HIV-exposed and infected infants.     

Thoracic wall involvement by Hodgkin disease and non-Hodgkin lymphoma: CT evaluation

Thoracic computed tomographic (CT) scans of 250 patients with newly diagnosed or recurrent lymphoma revealed thoracic wall involvement in 24 patients (11 with Hodgkin disease, 13 with non-Hodgkin lymphoma). Thoracic wall involvement occurred without contiguous mediastinal or parenchymal involvement in 17 patients. Of these, 13 patients had masses beneath the pectoralis muscles or within the breast, and four had masses arising from the ribs. Five additional patients had mediastinal masses with thymic involvement and parasternal extension through the thoracic wall. Pulmonary parenchymal lymphoma with thoracic wall invasion was noted in the remaining two patients. In five of nine patients receiving radiation therapy, treatment plans were modified by CT demonstration of thoracic wall lymphoma.     

Missed opportunities for measles immunisation in selected western Cape hospitals

Measles is still a major cause of childhood mortality and morbidity in South Africa. The World Health Organisation (WHO) has recently recommended that greater attention be paid to opportunities for immunisation in the curative sector. This study quantified the extent of missed opportunities for measles immunisation in children attending primary, secondary and tertiary level curative hospitals in the western Cape. Exit interviews of 1,068 carers of children aged between 6 and 59 months inclusive showed that 2.4-40.7% of carers had been requested to produce a Road-to-Health card, and that 4.8-43.1% of carers had a card available. The proportion of children with documented evidence of measles immunisation available ranged from 4.8% to 40.0% between facilities. The study demonstrated that a considerable number of potential opportunities to immunise children against measles are currently being missed in children attending hospitals and day hospitals in the western Cape. The study documents the effect of a fragmented approach to health care, and indicates a need for rapid integration of preventive and curative components of health care into a metropolitan-based primary health care service.