Surveillance of antibiotic resistance in invasive isolates of Neisseria meningitidis in Australia 1994-1999

A total of 1434 strains of Neisseria meningitidis isolated from cases of invasive meningococcal disease (IMD) in Australia between 1994 and 1999 were examined by standard methods for susceptibility to antibiotics used for treatment and prophylaxis. The proportion of isolates fully susceptible to penicillin decreased from 45% in 1994 to 26% in 1999 (P<0.001). All the other isolates were less sensitive to penicillin except for two meningococci with a penicillin MIC of 1 mg/l. The geometric mean penicillin MIC increased from 0.045 to 0.065 mg/l from 1994 to 1999. There was no significant difference in the geometric mean penicillin MICs of serogroup B and serogroup C meningococci. Penicillin susceptibility was significantly associated with a poorer outcome. Isolates from survivors of IMD had a higher geometric mean penicillin MIC (0.06 mg/l) than those from fatal cases (0.048 mg/l) (P< 0.001). This suggests that factors other than the decrease in susceptibility to penicillin observed were more relevant to outcome in IMD. All isolates were fully susceptible to ceftriaxone. Rifampicin resistance was infrequent (eight isolates in 6 years) and sporadic. A single isolate had decreased quinolone susceptibility. Despite the significant shift in susceptibility to penicillin recorded, this group of antibiotics remains a suitable treatment for IMD in Australia.     

Quantification of dentine shape in anthropoid primates

The external shape and thickness of the enamel component of primate molars have been employed extensively in phylogenetic studies of primate relationships. The dentine component of the molar crown also has been suggested to be indicative of phylogenetic relationships, but few studies have quantified dentine morphology in order to evaluate this possibility. To explore the utility of dentine shape as an indicator of phylogenetic affinity, a two-dimensional geometric morphometric analysis (EDMA-II) was performed using nine homologous land-marks on a sample of sectioned maxillary molars of extant ceboid, cercopithecoid, and hominoid primates. Results indicate that dentine shape (the configuration of the enamel-dentine junction, or EDJ) can distinguish taxa at every taxonomic level examined, including superfamilies, subfamilies, and closely related genera and species. This supports the idea that dentine morphology may be useful for phylogenetic studies. It is further suggested that the morphology of the EDJ may be more conservative than enamel morphology, and perhaps better-suited to phylogenetic studies. Among the samples studied, cercopithecoid primates have a unique dentine shape, and it is suggested that the development of bilophodont molars may be related to the distinctive EDJ configuration in cercopithecoids.     

APC from mice harbouring the filarial nematode, Brugia malayi, prevent cellular proliferation but not cytokine production

Specific T cell hyporesponsiveness and depressed antibody productionis a key feature of human infection with the filarial nematodes,Brugia malayi and Wuchereria bancrofti Despite this immune suppression,responses indicative of T_h2 subset activation are present, includingunusually high levels of specific lgG4. We tested the possibilitythat infection with filarial nematodes causes a reduction inthe co-stimulatory or antigen-presenting capacity of macrophagesresulting in a failure to activate specific T cells. Adherentperitoneal exudate cells (PEC) from mice implanted with adultB. malayi were used to present antigen to the conalbumin-specificT cell clone, D10.G4. Proliferation of the D10 cells at evenbackground levels was completely blocked by the presence ofimplant-derived adherent PEC. However, cytokine production bythese cells in response to antigen was intact, and thus PECfrom implanted mice are capable of functionally processing andpresenting antigen. The elicitation of a suppressive cell populationwas specific for live adults as cells from mice implanted withdead adult parasites effectively stimulated D10 proliferation.The block in cellular proliferation is not due to the productionof factors typically associated with macrophage suppressionsuch as nitric oxide, prostaglandins or catalase. These observationsare consistent with the T cell hyporesponsiveness seen in humancases of patent Brugia infection and may provide a murine modelfor the immune suppression seen in lymphatic filariasis.     

Time relationship of immune changes to HTLV-III/LAV seroconversion in patients with hemophilia

Longitudinal immune studies of patients with hemophilia A were begun in 1982 by the Regional Hemophilia Center in St. Louis, Missouri. Serum samples collected from 74 participants between 1982 and 1985 were analyzed for antibody to human T-lymphotropic virus type III (HTLV-III)/lymphadenopathy-associated virus (LAV). The incidence of antibody to HTLV-III/LAV has increased significantly in this population of patients with hemophilia. Only one of eight hemophiliacs had detectable antibody before July 1982, whereas 88.7% (55/62) were positive in 1985. T-cell surface markers were markedly abnormal in seropositive hemophilia patients with decreased percentage and number of OKT4-positive cells compared with seronegative hemophiliacs and controls. Lymphoproliferative responses to mitogens and antigens were normal in seronegative hemophilia patients. Seropositive hemophiliacs, compared with seronegative hemophiliacs, had significantly decreased lymphoproliferative responses, especially to pokeweed mitogen, tetanus, and Candida stimulations. Immune studies of seven HTLV-III/LAV seropositive hemophiliacs revealed antigen unresponsiveness and decreased T4 cells 2 to 32 months prior to development of full-blown AIDS. Longitudinal immune studies from 1983-85 revealed increasing number of seropositive hemophiliacs with antigen unresponsiveness and decreased T4 cells.     

Effect of accuracy constraint on joint coordination during pointing movements

Given the number of muscles and joints of the arm, more ways are available to produce an identical hand movement when pointing to a target than are strictly necessary. How the nervous system manages these abundant degrees of freedom was the focus of this study of pointing to targets of low and high indices of difficulty (ID). Two essential features of movement synergies were examined. The first reflects the preferred relations among the outputs of each movement element and was studied through principal component analysis. The second feature of synergy reflects the flexibility of those relationships evidenced by the use of multiple, goal-equivalent solutions to joint coordination. This second feature, which is the main focus of this report, was studied using the uncontrolled manifold approach. Motor abundance was defined operationally as the component of variance of joint combinations that left unchanged the value of important performance variables (goal-equivalent variability, GEV). This variance component was contrasted with the component of variance leading to a change in the value of these variables (non-goal-equivalent variability, NGEV). The difference between GEV and NGEV was evaluated with respect to the performance variables movement extent, movement direction, and path of the arm's center of mass. More than 90% of the variance of joint motions across the pointing trial were accounted for by one principal component, indicating a consistent temporal coupling among most joint motions in a single functional synergy. The flexible nature of this synergy was revealed by the variability analysis. All subjects had significantly higher GEV than NGEV for most of the movement path. Thus, variable patterns of joint coordination did not represent noise but the use of equivalent coordinative solutions related to stabilizing important performance variables. Higher GEV than NGEV was present regardless of the task's ID. One exception was at the time of peak velocity, leading to poorer control of movement extent than movement direction. Increasing the task's ID led to an overall reduction of joint configuraion variance, particularly GEV. These results support earlier work indicating that the use of goal-equivalent solutions to joint coordination is a common feature of the control of this and many other motor tasks. Functionally important performance variables appear to be controlled through flexible but task-specific coordination among the motor elements Electronic Publication     

Rotational moulding in the production of prostheses

This paper discusses the place of rotational moulding in the provision of prosthetic shanks and shank sections. It covers the selection of thermoplastic material, the moulding conditions and their automation in a machine process, and the development of a suitable range of moulds. Also covered is the question of interfacing between the moulded shank sections and other limb components, fatigue strength as tested to date and early results of patient field trials. The most developed of the possible prosthetic options available consists of a hollow tapered column having inserts at each end by which it is clamped through alignment couplings to the socket and foot respectively. For a below-knee application, the complete tapered column prosthesis weighs typically 1 kg. Static and fatigue testing of representative samples by the simultaneous application of compressive and bending loads to the maximum values specified by international standards exposed no failures by the time a million cycles had been reached. This method of fabrication has the merit of being capable of implementation locally on an "as required" basis. Additional advantages include the low cost of the mould tooling and the flexibility to mould a variety of shapes. Prosthetic feet are a possibility as are special shoes and orthotic parts. These may require other materials and experimentation is proceeding using structural and resilient foams.     

Serial Dexamethasone Suppression Tests and Clinical Outcome in ECT

Serial dexamethasone suppression tests (DST), obtained during a course of electroconvulsive therapy in 43 severely depressed patients, did not exhibit relationships between the initial DST, final DST, or the change in DST with clinical outcome measures at the time of discharge. In 37 patients reviewed six months after discharge, no relationship with the continuation of improvement, rehospitalization, or suicide was found. We are unable to confirm a clinical application for the DST in the management of patients during a course of convulsive therapy.     

Associations between admissions factors and the need for remediation

Advances in Health Sciences Education - This study examines the way in which student characteristics and pre-admissions measures are statistically associated with the likelihood a student will...