A preliminary study of black and white differences on the revised Wechsler intelligence scale for children

Investigated the performance of black and white children and youth on the WISC-R. The sample consisted of 120 Ss who were matched on the basis of their Full Scale WISC-R IQ score. Black males were matched with white males and black females were matched with white females, with 30 in each individual sample. The mean M.A. for the females was 10.6 and 10.0 for the males. Ss were matched in terms of Full Scale IQ. The Sander A statistical method was employed to analyze the data, and comparison of subtest scores between sexes was made by using the t-test for independent data. Evidence from the investigation indicates that the combined black sample performed better on the WISC-R Verbal Scale than did the white sample. Black males obtained significantly higher scores on Information and obtained higher scores on the four remaining Verbal scale subtests than did the white males. No differences were found between the females with regard to subtest scores. These findings did not support previous research that suggests that blacks tend to do more poorly on the Verbal area tests than on Performance tests of the WISC-R.     

家兔失神经支配腓肠肌肌纤维退行性变与修复性再生的超微结构观察

目的:观察家兔腓肠肌失神经支配后肌纤维在退行性变与修复性再生过程中超微结构的变化,探讨失神经支配骨骼肌修复性再生障碍的机制。方法:实验于2005-04/2006-04在南方医科大学中心实验室完成。选择成年新西兰大白兔20只,切断一侧胫神经腓肠肌肌支,术后1,4,8,12,16周分别采用耳缘静脉注射空气处死4只。取实验侧和对照侧腓肠肌内侧头肌组织少许,用于制备超薄切片标本,透射电镜观察各时间点兔失神经腓肠肌肌纤维形态。结果:纳入动物20只,均进入结果分析。①正常家兔腓肠肌肌原纤维排列整齐,肌小节和Z线清晰,线粒体均匀分布在肌原纤维之间,排列规则,细胞核位于质膜周边,未见溶酶体。②失神经支配1周,肌原纤维排列基本整齐,线粒体增多,无明显肿胀。③失神经支配4周,线粒体明显增多肿胀,部分线粒体空泡样变,溶酶体增多,Z线模糊,肌原纤维间隙增大。④失神经支配8周,肌纤维明显萎缩退行性变,大部分肌原纤维消失,残留的肌原纤维变得模糊,间隙增大,肌小结丧失正常的结构,胞浆内含有大量空泡变性的细胞器,可发现畸形核,染色质浓缩、边集,肌细胞膜极度皱缩。镜下发现较多的位于基膜下活化的肌卫星细胞,细胞内含有发达的粗面内质网和丰富的胞浆。一些肌卫星细胞直接与肌纤维融合。同时在间质中可发现一些形态上很象成纤维细胞的细胞,不过这些细胞含有大量的粗面内质网,胞浆内有颗粒和微丝,少量的圆形的线粒体。在退行性变的肌纤维基膜下也可发现肌管样结构的再生肌细胞,在这些肌管内一些肌丝在一起聚集成束,没有组装成肌原纤维,没有正常的肌小结结构。在它们周围有细小的空肌管样结构,可能是以往再生的肌细胞退行性变后的残余体。在间质中可发现一些细小的肌纤维。⑤失神经支配12周,大部分肌纤维萎缩退行性变,但是仍可发现没有萎缩的肌纤维,这些肌纤维细胞核位于周边,有良好的收缩系统,纤维排列规则,Z线清晰,有完整的肌膜。⑥失神经支配16周,肌卫星细胞的数量明显减少,并可发现大量细小的肌纤维,多分布在较大的肌纤维附近,肌膜完整平滑,无皱褶。可发现核位于中央的肌纤维,胞浆内肌原纤维结构清楚,但是肌原纤维的排列远不如核位于周边的肌纤维整齐,说明其收缩系统发育不良。结论:失神经支配后肌细胞退行性变和修复性再生同时存在,再生的肌细胞不能,化发育为成熟的肌纤维,进而发生退行性变。长时间失神经支配,肌卫星细胞的耗竭是失神经支配骨骼肌晚期的主要超微结构变化。     

Complex dislocation of the metacarpo-phalangeal joint of the index finger: A comparison of the surgical approaches

Complex dislocation of the index metacarpo-phalangeal joint almost always requires surgical intervention. Controversy exists as to the most suitable surgical approach to reduction: palmar or dorsal. We reviewed four cases and carried out dissections in eight cadaver hands to compare the surgical approaches. The interposed volar plate was found to be the most important obstacle to reduction. Both approaches were successful in obtaining reduction. The dorsal approach was simple and safe, but necessitated longitudinal division of the volar plate and may carry a theoretical risk of late instability. The palmar approach allows restoration of normal anatomy but the radial neurovascular bundle is always vulnerable.     

Results of surgical treatment for hyperparathyroidism associated with renal disease

Recently, the role and timing of surgery for treating secondary and tertiary hyperparathyroidism (HPT) have been questioned. In order to delineate the indications for surgery in these patients, a retrospective analysis of 53 consecutive patients treated with parathyroidectomy was conducted. Subtotal thyroidectomy was done in 37 of 45 patients undergoing their initial operations for HPT. Eight additional patients were referred after failed operations. Of 33 patients with preoperative bone pain, 70% improved. Joint pain improved in 87% of 30 patients, pruritus improved in 81% of 27 patients, and preoperative malaise improved in 73% of 33 patients after parathyroidectomy. Abdominal pain and irritated eyes were unlikely to improve. The best predictors of a successful outcome were a markedly elevated preoperative immunoreactive parathyroid hormone (mid-region) level and an elevated alkaline phosphatase level. There were no perioperative deaths. One patient (1.6%) had a recurrent laryngeal nerve injury, and one patient required reoperation for a neck hematoma. No patient had permanent hypoparathyroidism, but transient hypocalcemia (less than 7 mg/dL) occurred in 22%. Postoperative hypocalcemia correlated with elevated preoperative alkaline phosphatase levels (r2 = 0.247).     

Developmental and stage-specific expression of Smad2 and Smad3 in rat testis

Members of the transforming growth factor beta type (TGFbeta) superfamily and their receptors are expressed in the testis, and are believed to play important paracrine and autocrine roles during testicular development and spermatogenesis. The Smad proteins are downstream mediators for the family of TGFbeta growth factors. Smad2 and Smad3 are associated with both TGFbeta and activin signaling. However, very little is known about the expression and regulation of the Smad signaling proteins in the testis. In the present study, we have determined that Smad2 and Smad3 proteins are expressed in the postnatal testes of rats from 5 days to 60 days of age. Expression levels for both proteins are higher in young rats than in sexually mature rats. Smad2 and Smad3 messenger RNA levels parallel protein expression. Smad2 and Smad3 proteins are mainly localized in the cytoplasm of meiotic germ cells, Sertoli cells, and Leydig cells. Smad3 protein is localized to the nucleus of preleptotene to zygotene primary spermatocytes in young rats. Both proteins are expressed throughout all stages of the cycle of seminiferous tubules but are expressed at their lowest levels at stages VII-VIII in the seminiferous epithelium of adult rats. The presence of these downstream mediators in these cell types supports a role for TGFbeta and activin during spermatogenesis. The difference between the expression of Smad2 and Smad3 suggests that they may have different functions within the testis.     

Therapy of patients with human T-cell lymphotrophic virus I-induced adult T-cell leukemia with anti-Tac, a monoclonal antibody to the receptor for interleukin-2

Human T-cell lymphotropic virus I (HTLV-I)-induced adult T-cell leukemia (ATL) cells constitutively express interleukin-2 (IL-2) receptors identified by the anti-Tac monoclonal antibody (MoAb), whereas normal resting cells do not. This observation provided the scientific basis for a trial of intravenous anti-Tac in the treatment of nine patients with ATL. The patients did not suffer untoward reactions and did not have a reduction in the normal formed elements of the blood, and only one of the nine produced antibodies to the anti-Tac MoAb. Three patients had transient mixed, partial, or complete remissions lasting from 1 to more than 8 months after anti-Tac therapy, as assessed by routine hematologic tests, immunofluorescence analysis of circulating cells, and molecular genetic analysis of HTLV-I provirus integration and of the T-cell receptor gene rearrangement. The precise mechanism of the antitumor effects is unclear; however, the use of a MoAb that prevents the interaction of IL-2 with its receptor on ATL cells provides a rational approach for the treatment of this malignancy.     

A 10-year (2000-2010) systematic review of interventions to improve quality of care in hospitals

ABSTRACT: BACKGROUND: Against a backdrop of rising healthcare costs, variability in care provision and an increased emphasis on patient satisfaction, the need for effective interventions to improve quality of care has come to the fore. This is the first ten year (2000--2010) systematic review of interventions which sought to improve quality of care in a hospital setting. This review moves beyond a broad assessment of outcome significance levels and makes recommendations for future effective and accessible interventions. METHODS: Two researchers independently screened a total of 13,195 English language articles from the databases PsychInfo, Medline, PubMed, EmBase and CinNahl. There were 120 potentially relevant full text articles examined and 20 of those articles met the inclusion criteria. RESULTS: Included studies were heterogeneous in terms of approach and scientific rigour and varied in scope from small scale improvements for specific patient groups to large scale quality improvement programmes across multiple settings. Interventions were broadly categorised as either technical (n = 11) or interpersonal (n = 9). Technical interventions were in the main implemented by physicians and concentrated on improving care for patients with heart disease or pneumonia. Interpersonal interventions focused on patient satisfaction and tended to be implemented by nursing staff. Technical interventions had a tendency to achieve more substantial improvements in quality of care. CONCLUSIONS: The rigorous application of inclusion criteria to studies established that despite the very large volume of literature on quality of care improvements, there is a paucity of hospital interventions with a theoretically based design or implementation. The screening process established that intervention studies to date have largely failed to identify their position along the quality of care spectrum. It is suggested that this lack of theoretical grounding may partly explain the minimal transfer of health research to date into policy. It is recommended that future interventions are established within a theoretical framework and that selected quality of care outcomes are assessed using this framework. Future interventions to improve quality of care will be most effective when they use a collaborative approach, involve multidisciplinary teams, utilise available resources, involve physicians and recognise the unique requirements of each patient group.     

Generation of HIV-1 Resistant and Functional Macrophages From Hematopoietic Stem Cell�Cderived Induced Pluripotent Stem Cells

Induced pluripotent stem cells (iPSCs) have radically advanced the field of regenerative medicine by making possible the production of patient-specific pluripotent stem cells from adult individuals. By developing iPSCs to treat HIV, there is the potential for generating a continuous supply of therapeutic cells for transplantation into HIV-infected patients. In this study, we have used human hematopoietic stem cells (HSCs) to generate anti-HIV gene expressing iPSCs for HIV gene therapy. HSCs were dedifferentiated into continuously growing iPSC lines with four reprogramming factors and a combination anti-HIV lentiviral vector containing a CCR5 short hairpin RNA (shRNA) and a human/rhesus chimeric TRIM5α gene. Upon directed differentiation of the anti-HIV iPSCs toward the hematopoietic lineage, a robust quantity of colony-forming CD133⁺ HSCs were obtained. These cells were further differentiated into functional end-stage macrophages which displayed a normal phenotypic profile. Upon viral challenge, the anti-HIV iPSC-derived macrophages exhibited strong protection from HIV-1 infection. Here, we demonstrate the ability of iPSCs to develop into HIV-1 resistant immune cells and highlight the potential use of iPSCs for HIV gene and cellular therapies.     

Very old drivers: findings from a population cohort of people aged 84 and over

BACKGROUND: Increases in longevity will involve a significant increase among the number of drivers in the very old, who are at greater risk of being involved in road accidents. Data are thus needed from studies of older populations to characterize those still driving, the reasons for giving up and to help formulate appropriate policies for dealing with the problems faced and created by an increase in older drivers. METHODS: A driving questionnaire was administered to surviving members of a cohort comprising a representative sample of individuals aged >/=84, the Cambridge City over 75 Cohort. Out of 546 survivors 404 completed the driving questionnaire at the 9-year follow-up. In addition, subjects were assessed, at baseline and at each follow-up, for cognitive performance using the Mini-Mental State Examination (MMSE) and for physical impairment using the Instrumental of Activities in Daily Living (IADL) scale. RESULTS: Of the sample, 37% had driven in the past, and 8.4% were still driving, the majority regularly. The drivers tended to be younger (mean age 86.6 years), men (71%) and to be married (67.7%). Although physical disability and cognitive impairment are common in this age group, current drivers had few physical limitations on their daily activities and were not impaired on MMSE. None of the current drivers had visual impairment and 22.6% had hearing loss. Of those who had given up driving, 48.5% had given up at the age of >/=80. The commonest reasons for giving up driving were health problems (28.6%), and loss of confidence (17.9%). One-third reported giving up driving on advice. CONCLUSION: A process of self-selection takes place among older drivers. People over the age of 84 who are still driving have generally high levels of physical fitness and mental functioning, although some have some sensory loss. Given the likely increase in the number of older drivers over the next decades, safety will be improved most by strategies aimed at the entire driving population with older drivers in mind, rather than relying on costly screening programmes to identify the relatively small numbers of impaired older people who continue to drive.     

Experimental evidence against middle ear oxygen absorption

The present theory of eustachian tube (ET) function and middle ear (ME) ventilation posits that oxygen absorbed by the ME mucosa causes negative ME pressure which is relieved by periodic opening of the ET during swallowing and yawning. After developing a method to cannulate the ET of mongrel dogs we connected the cannulas hermetically to manometers. This system excluded ET function and tested the oxygen absorption capacity of the ME. When we controlled respiration and maintained blood gas PO2 and PCO2 at normal levels, we were unable to find any manometric evidence of negative pressure of gas absorption in the dog ME. Lowering the PCO2 and raising the PO2 of the blood by hyperventilation caused negative ME pressure which could be measured manometrically. We confirmed these findings with the tympanometer. Raising the PCO2 and lowering the PO2 by hypoventilation caused positive pressure in the ME. There is no evidence in these experiments that O2 absorption occurs or causes negative ME pressure in the dog. To the contrary there is evidence that elevated blood levels of the more diffusible CO2 cause an increase in the ME pressure and lowered CO2 level causes a negative ME pressure.