Foot contact angle variability during a prolonged run with relation to injury history and habitual foot strike pattern.

Foot strike pattern and movement variability have each been associated with running injuries. Foot contact angle (FCA) is a common measure of strike pattern. Thus, variability in FCA could be an important running injury risk factor. The purposes of this study were to compare (a) foot contact angle (FCA) and its variability between runners with and without injury history and, (b) FCA variability between habitual rearfoot strike (RFS) and non-RFS runners during a prolonged run. Twenty-three runners with and 21 without injury history participated. Motion capture was used to collect kinematic data during a 40 min treadmill run. Average FCA and its variability were compared between injury groups and among four time points. FCA and its variability were not different between runners with and without injury history or among time points during the run. FCA variability was lower in non-RFS compared to RFS runners (P < 0.001). Lower FCA variability in non-RFS runners may have implications for higher injury risks due to repeated localized tissue loading. Prospective analyses on the effects of lower FCA variability on injury risk are needed.

[The use of methylphenidate in children: analysis of prescription usage based in routine data of the statutory health insurance bodies concerning drug prescriptions]. / Der Einsatz von Methylphenidat im Kindesalter: Analyse des Verordnungsverhaltens auf der Basis von Routinedaten der gesetzlichen Krankenkassen zu Arzneimittelverordungen.

UNLABELLED: In Germany only few data is available on the use of stimulants in the treatment of Attention Deficit/Hyperactivity Disorder. For the first time a full survey of health insurance data was carried out on methylphenidate prescriptions from 2000 to 2001 in an East German District. 783 patients of the total cohort received at least one prescription for methylphenidate. In our sample, the treatment prevalence more than doubled in the observation period from 0.6 % to 1.4 % in children aged between 5 and 15 years, this age group representing the largest treatment group. Younger children, adolescents and adults were only rarely treated. The treatment was undertaken predominantly by paediatricians, general practitioners and neurologists/psychiatrists/child psychiatrists. Prescriptions were issued by one, or by not more than two doctors. CONCLUSION: In Mecklenburg-Vorpommern the prevalence of stimulant treatment has clearly increased. Since diagnosis-related data is not available it is not possible to assess the indications for treatment. Further studies should serve to evaluate the correspondence between diagnosis and therapy in relation to stimulant medication.

Visual scene memory and the guidance of saccadic eye movements.

An unresolved question is how much information can be remembered from visual scenes when they are inspected by saccadic eye movements. Subjects used saccadic eye movements to scan a computer-generated scene, and afterwards, recalled as many objects as they could. Scene memory was quite good: it improved with display duration, it persisted over time long after the display was removed, and it continued to accumulate with additional viewings of the same display (Melcher, D. (2001) The persistance of memory for scenes. Nature 412, 401). The occurrence of saccadic eye movements was important to ensure good recall performance, even though subjects often recalled non-fixated objects. Inter-saccadic intervals increased with display duration, showing an influence of duration on global scanning strategy. The choice of saccadic target was predicted by a Random Selection with Distance Weighting (RSDW) model, in which the target for each saccade is selected at random from all available objects, weighted according to distance from fixation, regardless of which objects had previously been fixated. The results show that the visual memory that was reflected in the recall reports was not utilized for the immediate decision about where to look in the scene. Visual memory can be excellent, but it is not always reflected in oculomotor measures, perhaps because the cost of rapid on-line memory retrieval is too great.

Shapes, surfaces and saccades.

Saccadic localization of spatially extended objects requires the computation of a single saccadic landing position. What representation of the target guides saccades? Saccades were examined for various targets composed of dots to determine whether landing position corresponded to the center-of-gravity (average location) of the dots, the center-of-area of the shape, or the symmetric axis. Targets were composed of dots configured as outline drawings of circles, ellipses, cardioids, wiggly lines, or amorphous blobs. In some cases, dot spacing was varied, extraneous dot clusters were superimposed, or different distributions of dots inside the boundary were added. Quasi-random dot clusters without a well-defined contour were also studied. Instructions were to look at the target as a whole, and keep latency long enough to avoid compromising accuracy. Saccades landed with a high level of precision (S.D.s 7-10% of target eccentricity) near the center-of-area of the target shape, rather than at the center-of-gravity of the dots or on the symmetric axis. Landing position was unaffected by the spacing of dots along the boundary, the addition of dots within the boundary, or the addition of the extraneous dot clusters. When the target was a cluster of quasi-random dots, saccades landed closer to the center-of-area of the implied surface than to the average location of the dots. Overall, the positions of individual dots were important only insofar as the dots affected overall target shape. The results show that a representation of target shape guides saccades, rather than a more primitive representation of individual elements within the attended region.

To operate or not to operate? The value of fine needle aspiration cytology in the assessment of thyroid swellings.

AIMS: To evaluate all thyroid fine needle aspirations (FNA) done over a six year period to assess the accuracy and value of the technique. METHODS: There were 335 FNAs of which 184 had subsequent histology and 49 others had clinical follow up, providing 233 patients for analysis. All cytology and histology was reviewed with no significant alterations in diagnosis. The FNAs were classified into three groups: benign, suspicious (recommend excision), and malignant. The histology and medical records were reviewed to determine whether the cytology was accurate. RESULTS: There were 130 benign FNAs, 126 had non-malignant histology or normal clinical follow up, and four had malignancies on histology (two lymphomas, one follicular carcinoma, and one carcinoma not otherwise specified). There were 45 suspicious FNAs. Of these five had either follicular or papillary carcinoma, 14 had follicular adenomas, and 26 had colloid nodular goitres or normal clinical follow up. Of the 21 malignant FNAs, 11 had carcinoma and 10 had either a non-malignant histology or normal follow up. There were 126 true negatives, 30 true positives, 4 false negatives, and 36 false positives. This gives a sensitivity of 88%, a specificity of 78%, a positive predictive value of 46%, a negative predictive value of 97%, and an accuracy of 80%. CONCLUSIONS: FNA cytology of the thyroid has a high negative predictive value, which is useful to reassure the majority of patients presenting with thyroid enlargement. However, a negative FNA should never exclude malignancy if there is a strong clinical suspicion. If this rule is adhered to a large number of patients will be spared unnecessary surgery and no malignant nodule will go untreated.

Differential expression of gp200-MR6 molecule in benign hyperplasia and down-regulation in invasive carcinoma of the breast.

In this study, we used immunohistochemical and biochemical analysis to show that gp200-MR6, a 200 kDa molecule that is functionally associated with the human interleukin 4 (IL-4) receptor complex, is expressed at high levels on normal breast epithelial tissues, at lower levels on in situ carcinomas, and that the expression is lost in the invasive carcinoma of the breast. Furthermore, a preliminary study showed that benign epithelial hyperplasia of the breast expresses the gp200-MR6 heterogeneously. Two populations of cells have been observed: MR6 positive and MR6 negative. Interestingly, MR6-positive cells were observed to have different morphology from those that were MR6 negative; the nuclei of the former were larger and rounded in shape, whereas the nuclei of the latter were relatively small and oval in shape. In sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) and Western blotting, monoclonal antibody MR6 detects the same molecular weight molecule in both normal and transformed tissue, indicating that the molecule is not a product of a truncated gene. The intensity of the gp200-MR6 bands correlates with the immunohistochemical data, indicating that the molecule is expressed at high levels in normal tissue and at lower levels in malignant tissue. These results suggest that analysis of gp200-MR6 expression may be useful in tumour grading and prognostic evaluation in breast cancer. Moreover, the molecule may be involved early in the process of tumorigenesis of the breast, in which a loss or a down-regulation of gp200-MR6 could contribute towards tumour development and progression via an effect on cell growth and differentiation.

Role of re-screening of cervical smears in internal quality control.

AIMS: To investigate the use of rapid re-screening as a quality control method for previously screened cervical slides; to compare this method with 10% random re-screening and clinically indicated double screening. METHODS: Between June 1990 and December 1994, 117,890 negative smears were subjected to rapid re-screening. RESULTS: This study shows that rapid re-screening detects far greater numbers of false negative cases when compared with both 10% random re-screening and clinically indicated double screening, with no additional demand on human resources. The technique also identifies variation in the performance of screening personnel as an additional benefit. CONCLUSION: Rapid re-screening is an effective method of quality control. Although less sensitive, rapid re-screening should replace 10% random re-screening and selected re-screening as greater numbers of false negative results are detected while consuming less resources.

Interobserver variation in the reporting of the histopathological grading of anal intraepithelial neoplasia.

AIM: To assess the consistency in the histological reporting of anal intraepithelial neoplasia (AIN) among experienced histopathologists. METHOD: One hundred anal biopsy specimens were retrieved from archival material at St Mark's Hospital, London and graded by five histopathologists according to criteria outlined by Fenger (six point scale, ranging from normal to invasive carcinoma). RESULTS: There was only moderate agreement among the pathologists, with unweighted k scores ranging from 0.09 to 0.48, and weighted k scores of 0.17 to 0.60. CONCLUSIONS: There is considerable interobserver variation in the reporting of AIN. A simplified system of grading may help to abolish this.

Identification of glioma-associated antigen MUC 2-63 as CD44.

Monoclonal antibody MUC 2-63 recognises neurogenic tumours and has been used successfully for radioimaging human malignant gliomas. We now show that the MUC 2-63 antigen has the same tissue distribution and molecular weight range as the CD44 antigen and confirm the identity of these two molecules in blocking studies using MUC 2-63 and the CD44 anti-framework antibody F10-44-2. Thus not only MUC 2-63 but also other anti-CD44 monoclonal antibodies should prove useful in imaging and, perhaps, therapy of brain tumours.

The use of cytology in the diagnosis of basal cell carcinoma.

Two hundred and forty patients with basal cell carcinomas (BCCs) on the head or neck were studied. Scrapings of the lesions were taken for cytological examination, and a 3-mm punch biopsy was performed for histopathological study. The accuracy of diagnosis by each method was compared. Both methods confirmed the clinical diagnosis in 226 cases, and both were negative in 10 cases. Cytopathology gave one false negative result (0.42%), and histopathology gave two false negative results (0.83%). Cytopathology gave one false positive result (0.42%), and histopathology did not produce any false positive results. We conclude that cytological examination of skin scrapings from suspected BCCs is a rapid and reliable method of diagnosis.

Rapid cervical cytology screening.

2030 Papanicolaou-stained cervical smears were submitted for rapid screening prior to routine screening; 30 seconds were allowed for each slide, and those thought to be abnormal were identified. The results were compared with those of conventional screening. All severe and moderately dyskaryotic cases were detected by the rapid technique, as were the majority of mild dyskaryosis and borderline cases. When a laboratory has a backlog it may be worth rapid-screening all slides in addition to routine screening, so that patients most at risk can receive prompt treatment.

Tumour-associated upregulation of the IL-4 receptor complex.

In a previous study we have shown that monoclonal antibody MR6, which we believe recognizes a component of the human IL-4 receptor complex, binds to a wide variety of epithelial tumours. We have now used this reagent to carry out more detailed analysis of tumours of the breast. Our immunohistochemical data indicate that approximately 30% of these tumours show elevated expression of the molecule to which MR6 binds. In addition, three samples of lymphoma were all MR6-positive. Normal breast tissue from the same patients was either negative or weakly positive. Immunoprecipitation and Western blotting analysis with MR6 show that the molecule expressed on tumour cells is indistinguishable from that on normal tissues. It has an apparent molecular weight of 200 kD, but is highly sensitive to proteolysis yielding a molecule of 145 kD. These data raise the possibility that upregulation of the IL-4 receptor complex may be involved in tumourigenesis. In addition, since only a third of tumours are MR6-positive, the antibody may have potential in differential diagnosis.