Actin mutations are one cause of congenital fibre type disproportion

We report three heterozygous missense mutations of the skeletal muscle alpha actin gene (ACTA1) in three unrelated cases of congenital fiber type disproportion (CFTD) from Japan and Australia. This represents the first genetic cause of CFTD to be identified and confirms that CFTD is genetically heterogeneous. The three mutations we have identified Leucine221Proline, Aspartate292Valine, and Proline332Serine are novel. They have not been found previously in any cases of nemaline, actin, intranuclear rod, or rod-core myopathy caused by mutations in ACTA1. It remains unclear why these mutations cause type 1 fiber hypotrophy but no nemaline bodies. The three mutations all lie on one face of the actin monomer on the surface swept by tropomyosin during muscle activity, which may suggest a common pathological mechanism. All three CFTD cases with ACTA1 mutations had severe congenital weakness and respiratory failure without ophthalmoplegia. There were no clinical features specific to CFTD cases with ACTA1 mutations, but the presence of normal eye movements in a severe CFTD patient may be an important clue for the presence of a mutation in ACTA1.     

A prospective study of assault against staff by youths in a state psychiatric hospital

OBJECTIVE: This study examined the frequency and nature of violence directed at staff in a state inpatient psychiatric hospital for children and adolescents. METHODS: A total of 215 assaults that occurred over a two-month period were examined by using information obtained from staff at the time of the assault and from the hospital database. Assaults were analyzed for situational characteristics of the incidents as well as the characteristics that best differentiated between assaultive and nonassaultive patients. RESULTS: Thirty-three percent of all hospitalized patients were involved in an assaultive incident. A majority of the patients who assaulted staff were neither involved in the juvenile justice system nor psychotic. Although youths who were involved in repeat assaults were more likely to be male, gender did not differentiate between those who were assaultive toward staff and those who were not. Some type of verbal direction or redirection (typically minor) on the part of the staff preceded a majority (68 percent) of the assaults. CONCLUSION: Preconceived notions about why youths assault staff at psychiatric hospitals do not appear to be validated by these data, which suggest a more complex picture.     

Expression of CD47 (integrin-associated protein) decreases on red blood cells during storage.

In light of recent studies that demonstrate that CD47 antigen is an important "self-recognition" marker involved in protecting circulating red blood cells (RBCs) from phagocytosis by macrophages, the aim of the present study was to investigate whether CD47 expression on RBCs is altered during storage. Red cell concentrates (RCCs) were prepared and stored at 4 degrees C and samples were collected on days 1, 14, 28 and 42 post donation. RBCs were labelled with anti-CD47 antibody and analysed by flow cytometry. A small but significant and progressive decrease in CD47 antigen expression was observed in non-irradiated and irradiated RBCs stored for 14 days onwards. CD47 was also detected in increasing quantities in supernatant from RCCs after 14 days of storage. It is proposed that loss of CD47 during storage, in addition to other biophysical changes, may target many transfused RBCs for clearance from the transfusion recipient's circulation.     

Effect of a patient training video on visual field test reliability

AIMS: To evaluate the effect of a visual field test educational video on the reliability of the first automated visual field test of new patients. METHODS: A prospective, randomised, controlled trial of an educational video on visual field test reliability of patients referred to the hospital eye service for suspected glaucoma was undertaken. Patients were randomised to either watch an educational video or a control group with no video. The video group was shown a 4.5 minute audiovisual presentation to familiarize them with the various aspects of visual field examination with particular emphasis on sources of unreliability. Reliability was determined using standard criteria of fixation loss rate less than 20%, false positive responses less than 33%, and false negative responses less than 33%. RESULTS: 244 patients were recruited; 112 in the video group and 132 in the control group with no significant between group difference in age, sex, and density of field defects. A significant improvement in reliability (p=0.015) was observed in the group exposed to the video with 85 (75.9%) patients having reliable results compared to 81 (61.4%) in the control group. The difference was not significant for the right (first tested) eye with 93 (83.0%) of the visual fields reliable in the video group compared to 106 (80.0%) in the control group (p = 0.583), but was significant for the left (second tested) eye with 97 (86.6 %) of the video group reliable versus 97 (73.5%) of the control group (p = 0.011). CONCLUSIONS: The use of a brief, audiovisual patient information guide on taking the visual field test produced an improvement in patient reliability for individuals tested for the first time. In this trial the use of the video had most of its impact by reducing the number of unreliable fields from the second tested eye.     

Foot-targeting in reaching and grasping

Foot positioning was investigated when right-handed (Experiment One) and left handed adults (Experiment Two) stopped walking to grasp a stationary 70 mm ball at shoulder height. In both experiments centroid location formed by the toe and heel coordinates relative to the object was highly consistent within a target-location condition, demonstrating a foot-targeting phenomenon. Centroid location in the anterior-posterior direction was uninfluenced by grasping hand but the centroid shifted right for left hand grasps and left for right hand grasps. With the target either centrally located or on the same side as the dominant hand, foot positioning brought the grasping hand closer to the target in the medial-lateral direction. When the target object was aligned with the shoulder opposite the dominant hand both groups adopted foot positions to the left of the target. Thus, neither group adopted optimal foot position when the target was located opposite their dominant hand. Foot orientation angle relative to the target was also influenced by choice of grasping hand. Collectively, the findings demonstrate a close association between grasping hand and foot position when approaching to reach and grasp an object but also suggest that foot-dominance may influence medial-lateral centroid location.     

The assessment of lens opacities in clinical practice: results of a national survey

AIM: To investigate the examination of lens opacities in routine ophthalmic clinical practice. METHOD: A questionnaire survey was mailed to 703 consultant ophthalmologists in the UK. The surgeons were asked which lens feature(s) they assessed in their clinics when deciding whether to offer cataract surgery. RESULTS: 489 replies were received. A broad range of lens opacities was assessed, with differences between surgeons for some opacities with high prevalences in the population, particularly cortical opacities. Many (74% of 467) surgeons assessed one or more lens opacities (anterior subcapsular cataract, vacuoles, water clefts, coronary flakes, focal dots, retrodots, fibre folds) which may be visually important but which have received relatively little attention by researchers. CONCLUSIONS: Some classes of lens opacity which are traditionally measured by researchers may be ignored in clinical practice and opacities which are traditionally ignored by some researchers are regarded as clinically important by a substantial number of surgeons.     

Bone lead and blood lead levels in relation to baseline blood pressure and the prospective development of hypertension: the Normative Aging Study

Between 1991 and 1997, the authors studied 833 participants of the Normative Aging Study in a substudy of bone lead levels (measured by K-shell x-ray fluorescence), blood lead levels, and hypertension. Among these subjects, 337 were classified as normotensive, and 182 and 314 were classified as having borderline and definite hypertension, respectively, at baseline. These bone and blood lead levels were typical of those of community-exposed men. Among the 519 subjects with no history of definite hypertension at baseline, cross-sectional analyses revealed positive associations between systolic blood pressure and bone lead levels. Of the 474 subjects who were free from definite hypertension at baseline and had follow-up data, 74 new cases of definite hypertension were reported. Baseline bone lead levels were positively associated with incidence of hypertension. In proportional hazards models that controlled for age, age squared, body mass index, and family history of hypertension, an increase in patella (trabecular) lead from the midpoint of the lowest quintile to that of the highest quintile was associated with a rate ratio of definite hypertension of 1.71 (95% confidence interval: 1.08, 2.70). No association was found with blood lead level. These results support the hypothesis that cumulative exposure to lead, even at low levels sustained by the general population, may increase the risk of hypertension.     

Visual expertise in the perception of action

Within the exercise and the sports sciences, various "expert observers" rely on visual assessments of movement. Strengths and limitations of unaided observation are outlined based on the biological motion perception literature and related work. The concepts of coordination, control, and action are used to propose an "action prototype" for pattern recognition.