AUTACOID INTERACTIONS IN THE REGULATION OF BLOOD FLOW IN THE HUMAN PLACENTA

1. Interactions between autacoids may play important roles in the regulation of blood flow in the foetal placenta. In order to investigate this aspect of placental haemodynamics, human normal-term placentae were perfused in vitro and the responses of the foetal vessels to various combinations of vasoactive agents were determined. 2. Vasoconstriction responses to 5-hydroxytryptamine (5-HT) were potentiated in the presence of endothelin-1 (ET-1), the thromboxane A₂-mimetic U46619 and a nitric oxide synthase inhibitor, N-nitro-l -arginine (NOLA), but not in the presence of angiotensin II. 3. N-Nitro-l -arginine caused vasoconstriction of the perfused placenta and indomethacin attenuated this effect and blocked the potentiation of the 5-HT response by NOLA. 4. Indomethacin did not affect ET-1-induced pressure increases and infusion of U46619 had no effect on release of ET-Iike immunoreactivity into the foetal placental circulation. 5. The present study provides evidence of interactions between several autacoids in human perfused placentae in vitro. These interactions may play important roles in foetal placental haemodynamics in normal or pathological situations.     

Induction of an anomalous blue-green wavelength discrimination by reduced viewing time

Wavelength discrimination was studied on three colour-normal human observers for open viewing and for reduced time viewing. All three observers show a loss of blue-green wavelength discrimination when viewing time is reduced to 3.75 msec. This loss is shown to be an effect of viewing time alone and not of reduced retinal illuminance. The results confirm those reported by Foster, Scase and Taylor¹ although the target size and methodology are different.     

Attention deficit hyperactivity disorder: Perceptions, practice and politics

Abstract: Some of the issues related to the doubts and complexities involved in the diagnosis and treatment of attention deficit hyperactivity disorder (ADHD) are reviewed. While some writers claim that it is clear that all children presenting with ADHD should be treated by pharmacological means, there are associated risks and politics. However, in the absence of well established and research-supported alternative understandings of the aetiology and treatment of the disorder, many practitioners feel unable to offer a useful service. Resulting frustrations have led some parents to form their own support networks, which make strong demands for increased services. More creative and innovative therapeutic interventions focusing on the broader impact of ADHD must be developed to deal with this disorder.     

MULTIDRUG RESISTANT TUBERCULOSIS – BIOMECHANISM,EPIDEMIOLOGY AND MANAGEMENT STRATEGIES

Muitidrug resistant tuberculosis has shown an alarming increase and this assumes added importance in view of the increasing number of HIV infected patients. This article reviews the biomechanism of resistance and discusses the present stategies that are available and recommended to tackle the rising incidence of tuberculosis due to resistant mycobacteria.KEYWORDS: Antitubereular drugs, Drug resistance, Mycobacterium tuberculosis     

Early cognitive impairment: Role of clock drawing test

Background: Folstein's Mini Mental Status Examination (MMSE) often fails to identify executive dysfunction even if quite severe. Detailed neuropsychological tests and extensive bedside tests are available to evaluate executive function, but most of them are time consuming. This study was done to determine the value of a Clock Drawing Test (CDT) as a simple tool to identify cognitive dysfunction in various neurological disorders and to assess its utility as an adjunct to MMSE in identifying executive dysfunction in a a busy out patient department (OPD).