Reconstruction of three-dimensional anatomical landmark coordinates using video-based stereophotogrammetry

A method is described for reconstructing the 3-dimensional coordinates of anatomical landmarks from multiple video images. This method consists of 2 stages: (1) separate reconstructions of landmark coordinates visible in dorsal and ventral orientations using Direct Linear Transformation (Abdel-Aziz & Karara, 1972), and (2) least-squares alignment of the partial reconstructions using landmarks present in both. The repeatability of the overall reconstructions and of individual landmarks were assessed by performing multiple independent reconstructions of landmark coordinates for 2 canid specimens. Results indicate that the repeatability of interlandmark distances based on stereophotogrammetric reconstructions from standard-resolution video images is comparable to that of caliper measurement, and slightly superior to that of electronic 3-dimensional digitisation. At least 4 images should be available per landmark for optimal repeatability, but additional images allow only a slight increase in repeatability.     

The cold pressor test: Vascular and myocardial response patterns and their stability

The purposes of the present study were to compare the cardiovascular response patterns evoked by three versions of the cold pressor test (either forehead stimulation or hand or foot immersion) and to determine the reproducibility of the responses over a 2-week interval. Blood pressure, heart rate, stroke volume, cardiac output, total peripheral resistance, and systolic time intervals were obtained during rest and during the cold pressor test in 42 young men. Across conditions, the pressor response was supported by peripheral resistance increases with concomitant stroke volume decreases. Although the response panerns were generally similar across sites, exceptions were apparent for heart rate. Forehead stimulation was characterized by no significant change in heart rate, whereas limb (hand or foot) immersion was associated with significant heart rate acceleration. The responses elicited by the three cold pressor test conditions were reliable and showed little evidence of attenuation over the test-retest interval.     

CASE REPORT: Antibiotic-associated haemorrhagic colitis

Antibiotic-associated haemorrhagic colitis is an uncommon cause of bloody diarrhoea in patients taking penicillin or penicillin-related antibiotics. Symptoms of abdominal pain and bloody diarrhoea occur within 1 week of antibiotic use and resolve without specific therapy within days of discontinuing the offending antibiotic. There is an apparent increased incidence of the disease in patients of Oriental ethnicity. The pathogenesis is unknown. We present two cases of haemorrhagic colitis in patients taking penicillin-related antibiotics who presented within 4 months of each other. One of the patients was being treated for Helicobacter pylori infection. The published literature is reviewed with particular emphasis on the histology and pathogenesis of the condition.     

Visual event-related potentials in first-episode psychotic patients and their relatives

We conducted a comprehensive examination of the sensory visual event-related potential (ERP) of psychiatric patients and their relatives using a methodology that improves upon those used previously by other investigators. One hundred thirty-five patients at the onset of their first psychotic episode, 146 first-degree relatives of these patients, and 113 normal controls were exposed to light flashes of four different intensities while their ERPs were recorded from three central scalp sites. For most analyses, various ERP amplitude measures did not discriminate the different psychiatric groups or their relatives either from one another or from the normal controls. These findings indicate that patients with schizophrenia, schizophreniform disorder, and affective disorder at the early stage of their illness do not display significant deficits in the processing and regulation of simple sensory visual stimulation.     

Antisperm Antibodies Detected by ZER Enzyme-Linked Immunosorbent Assay Kit Are Not Those Detected by Tray Agglutination Test

ABSTRACT: Antisperm antibodies may play a role in the pathogenesis of infertility, particularly in the male. One of the standardized methods for detecting antisperm antibodies is the tray agglutination test (TAT). Unfortunately, this assay requires fresh motile spermatozoa. Tests for binding of antibody to fixed sperm or sperm extracts have been developed as enzyme-linked immunosorbent assays (ELISA), and we compared the results of using one such ELISA method with the TAT to detect antisperm antibodies in a panel of known positive and negative sera from infertile and control patients. With respect to the TAT assay, the ELISA gave a 75% false-positive test rate and a 63% false-negative rate. It is important to validate new assays such as the ELISA before widespread application to patient screening particularly since patients judged to have antisperm antibodies may be treated with high-dose corticosteroid drugs that are not without significant side effects.     

Stillbirth and birth order

1. Some stillbirth sibships are characterized by positive birth-order effects, and among them some are probably of the sort illustrated by Fig. 1; other stillbirth sibships are characterized by negative order effects, and among them some are probably of the sort illustrated by Fig. 2. 2. The ‘strength’ of these two opposing effects was roughly equal in the sample tested, so there was no over-all trend of stillbirths with birth order within sibships. 3. There seem to be a few sibships in which a curvilinear effect is present, with higher risks of stillbirth at the beginning and at the end of the same sibship. 4. Lastly, it seems possible (though no direct evidence on this point has been presented in this paper) that many stillbirths belong to sibships which do not exemplify any appreciable maternal age or order effect. 5. It seems likely that the positive and negative effects are related to specific pathological causes of stillbirth. 6. It seems possible that the occasional sibship seeming to show higher risks at both ends is due to the co-existence in a single woman of a propensity to bear two types of stillbirth—one type characterized by a positive effect, and the other by a negative effect. 7. The stillbirth ratio declines from the 1st to the 2nd and 3rd birth ranks, and thereafter increases. 8. The initial drop is due to a genuine negative birth order (or maternal age) effect. 9. The subsequent rise seems to be not primarily due to secular changes within individual women (either as a result of maternal age or birth order) but to an association of fertility with proneness to stillbirth. The cause may thus be social rather than biological. 10. The cause of this association is not that a stillbirth is likely to occasion reproductive compensation. (Indeed in this sample, at all the birth ranks up to the ninth, a stillbirth promoted birth limitation instead.) 11. The association of fertility with a propensity to stillbirth may be mediated by social class or by duration of marriage, but it is not clear that the underlying cause of this association has been uncovered. 12. One recommendation would follow from this work if its findings should be confirmed: stillbirth-prone women on the average have more pregnancies than other women. This fact is a major cause of the variation of stillbirths rate with birth rank. This being so, workers using multivariate analysis may feel the need to scrutinize the assumptions implicit in their models.