Hypoplasia of the cerebellar vermis in neurogenetic syndromes

There are conflicting reports on the relationship between cerebellar vermal lobule hypoplasia and autism. Using quantitative magnetic resonance image analysis, we measured the cerebellar vermis in 125 normal individuals with a broad age range and 102 patients with a variety of neurogenetic abnormalities. We conclude that hypoplasia of cerebellar vermal lobules VI and VII is a nonspecific finding that even occurs in several conditions without autistic behavior. This suggests that it is not a specific neuroanatomical marker for autism, nor is cerebellar dys- genesis likely to be solely responsible for clinical autistic behaviors.     

Development of neurochemical separation of ON and OFF channels at retinal ganglion cells

Anatomical and physiological segregation of neurons into ON (brightening detector) and OFF (darkening detector) channels in the retina and subsequent visual system ensure the high sensitivity required for contrast detection and spatial discrimination. This segregation is finest at the visual axis. Neurochemically, ON and OFF ganglion cells at the visual axis seem to be distinguished by different inhibitory transmitters but not excitatory transmitters. Microiontophoretic studies of inhibitory transmitters on the retinal ganglion cells in kittens and adult cats suggest that this neurochemical distinction is poor in immature ganglion cells at the visual axis. Initially both ON and OFF cells seem to be supplied by GABAergic, glycinergic, and catecholaminergic amacrine cells, but in adults, ON cells remain supplied only by GABAergic amacrines, while OFF cells are supplied by glycinergic amacrines. Postnatal elimination of multiple inputs and strengthening of the appropriate inputs, as seen in the central nervous system, also seem to occur at the retinal neurotransmitter synapses during development.     

Patient-Physician Pairing: Does Racial and Ethnic Congruity Influence Selection of a Regular Physician?

Many public and private sector efforts are devoted toward increasing the training of physicians from under-represented minority groups, yet little has been documented regarding the association between physicians' racial backgrounds and the patient populations they serve. To address this question, we use 1987 National Medical Expenditure Survey to examine the impact of race/ethnicity on the matching between physician and patients. Our results show that minority patients are significantly more likely to report having a minority physician as their regular doctor. We estimate that minority patients are five times as likely as non-minorities to report that their regular physician is a member of a racial/ethnic minority. This effect is especially pronounced among Hispanics who identify a Hispanic physician as their regular provider 19 times more often than non-minorities. After controlling for other socio-economic factors, both these figures remain significant, but drop by approximately one-half. These results support the notion that minority patients tend to see minority physicians at a disproportional rate independent of other socio-economic factors.     

Preventive care for patients following myocardial infarction. The Wessex Research Network (WReN)

OBJECTIVE: We aimed to assess general practice care for patients following a myocardial infarction (MI). METHOD: A structured review was carried out of general practice records of patients identified from hospital administration data. A total of 266 survivors following MI were identified from the discharge data of 13 hospitals in Southern England and registered with 71 GPs belonging to the Wessex Research Network. Median time since hospital discharge was 2.1 years. The main outcome measures were the provision of appropriate preventive care, including cardiac rehabilitation, drug therapy, and lifestyle advice for modifiable risk factors. RESULTS: Basic care was provided to nearly all patients; 253 (95.1%, 95% Cl 91.8-97.4) had blood pressure documented after their MI, 216 of 234 patients eligible for aspirin (92.3%; 88.1-95.4) had been recommended treatment, and the provision of advice on smoking cessation was documented for 27 of 33 continuing smokers (81.8%; 64.5-93.0). However, only 73 of 236 patients eligible to attend a structured rehabilitation programme (30.9%; 25.0-36.8) were documented as having received rehabilitation. Of 89 patients with heart failure following MI, 33 (37.1%; 27.1-48.0) had no record of having been offered treatment with an ACE inhibitor. Total cholesterol measurement was documented for only 144 patients (54.1%; 48.1-60.1). We estimate that there is still the potential to prevent between 4 and 9 deaths in this group of 266 surviving patients in the next 2 years by further improving the quality of follow-up care. CONCLUSIONS: Preventive care in patients with proven ischaemic heart disease in general practice remains haphazard, even among doctors enthusiastic to participate in research and to audit their quality of care. As general practitioners we should ensure that we are providing high quality preventive care to patients with clinical disease before we focus on the even more demanding task of primary prevention.      

Albuterol Delivery by Metered-Dose Inhaler With a Pediatric Mechanical Ventilatory Circuit Model

Study Objective . To determine albuterol delivery by metered-dose inhaler (MDI) in an in vitro pediatric mechanical ventilatory circuit model. The influence of a spacing device, endotracheal tube (ETT) diameter and length, and air humidity was also investigated. Design . An albuterol MDI canister was connected to an AeroVent spacer or Airlife MDI adapter and ETT 4.0, 5.0, or 6.0 mm at commercially available and equal lengths. The ETT tip was attached to an in-line filter holder with a 1-μm type A/E glass fiber filter. Ventilator settings were fractional concentration of inspired oxygen 50%, tidal volume 250 ml, inspiratory:expiratory (I:E) ratio 1:3, rate 25 breaths/minute, temperature 35°C, and a decelerating flow pattern. Ten albuterol canisters were activated two times each (total 2000 μg) into dry (4.0-, 5.0-, and 6.0-mm ETT) and humidified air (4.0- and 6.0-mm ETT) and repeated in triplicate. Percentage MDI output was determined by weighing the filter before and after drug administration (balance sensitivity 10 μg). Significant differences (p≤0.05) among the groups with and without a spacer and in dry and humidified air were determined by ANOVA with Scheffe's multiple comparison test. Multiple regression was used to determine significant associations between ETT diameter and length and delivery. Main Results . With the AeroVent spacer in humidified air, delivery with the 4.0- and 6.0-mm ETT was approximately 2.3% and 5%, respectively. The spacer and dry air significantly improved delivery. Conclusions . In humidified air, the dose of albuterol by MDI with an AeroVent spacer should be doubled for children intubated with 6.0-mm ETT, and four puffs administered for every one puff desired for 4.0-mm ETT. The results of this investigation should prove useful in initial clinical trials of albuterol MDI in ventilator-dependent infants and children.     

Different effects of unilateral versus bilateral subthalamic nucleus stimulation on walking and reaching in Parkinson's disease.

The purpose of this study was to determine the effects of unilateral versus bilateral subthalamic nucleus (STN) stimulation on quantitative measures of walking and reaching in Parkinson's disease (PD). We used kinematic measures and the Unified Parkinson's Disease Rating Scale (UPDRS) motor subscale (subscale III) to evaluate the movement of 6 people with PD who had bilateral STN stimulators implanted for at least 6 months and withheld their anti-parkinson medication for at least 8 hours. Subjects were studied with both stimulators off, one on, and both on. Kinematic data were collected as subjects walked, reached to a target, and were rated using the UPDRS motor subscale. STN stimulation improved walking speed and stride length, with the greatest benefit from bilateral stimulation. Reaching speed was improved by unilateral STN stimulation alone, with no additive effect of bilateral stimulation. UPDRS motor subscale ratings paralleled the kinematic findings. STN stimulation did not restore PD subjects' movements to the level of age-matched controls. Overall, these results provide further evidence that the basal ganglia pathways involved in control of walking and reaching may be distinct. We speculate that basal ganglia may influence walking through bilateral pedunculopontine projections and reaching through ipsilateral thalamocortical projections. Our findings also suggest that maximal improvement of walking requires bilateral rather than unilateral STN stimulation.     

Prevalence of knee abnormalities in patients with osteoarthritis and anterior cruciate ligament injury identified with peripheral magnetic resonance imaging: a pilot study.

OBJECTIVES: 1) To assess, with a peripheral magnetic resonance imaging system (pMRI), the prevalence of bony and soft tissue abnormalities in the knee joints of normal subjects, osteoarthritis (OA) patients, and individuals who have suffered an anterior cruciate ligament (ACL) rupture; and 2) to compare the prevalence among groups. METHODS: Magnetic resonance (MR) images of 28 healthy, 32 OA, and 26 ACL damaged knees were acquired with a 1.0-T pMRI system. Two radiologists graded the presence and severity of 9 MR image features: cartilage degeneration, osteophytes, subchondral cyst, bone marrow edema, meniscal abnormality, ligament integrity, loose bodies, popliteal cysts, and joint effusion. RESULTS: Ten of 28 healthy (35.7%), 24 of 26 ACL (92.3%), and all OA knees (100%) showed prevalent cartilage defects; 5 healthy (17.9%), 20 ACL (76.9%), and all OA knees (100%) had osteophytes; and 9 normal (32.1%), 21 ACL (80.8%), and 29 OA knees (90.6%) had meniscal abnormalities. One-half of the knees in the OA group (16 of 32, 50%) had subchondral cysts, and almost one-half had bone marrow edema (15 of 32, 46.9%). These features were not common in the ACL group (7.7%, and 11.5%, respectively) and were not observed in healthy knees. The OA group had the most severe cartilage defects, osteophytes, bone marrow edema, subchondral cysts, and meniscal abnormalities; the ACL group showed more severe cartilage defects, osteophytes, and meniscal abnormalities than did normal subjects. CONCLUSION: The results suggest that knees that have sustained ACL damage have OA-like reatures; most subjects (19 of 26, 73.1%) could be identified as in the early stage of OA. The prominent abnormalities present in ACL-damaged knees are cartilage defects, osteophytes, and meniscal abnormalities.