Pectenotoxins - an issue for public health - A review of their comparative toxicology and metabolism

Pectenotoxins (PTXs) are a group of toxins associated with diarrhetic shellfish poisoning (DSP) and isolated from DSP toxin-producing dinoflagellate algae. Consumption of shellfish contaminated with PTXs has been associated with incidences of severe diarrhetic illness resulting in hospitalisation. Concern has been raised for public health following the discovery that these toxins are not only hepatotoxic and can cause diarrhetic effects in mammals, but that they are potently cytotoxic to human cancer cell lines and have been found to be tumour promoters in animals. With advances in knowledge and technology, more PTXs are being identified, but little is known of their toxicology and the potential impact these toxins may have on public health in the long term. Without such information, adequate health-risk assessments for the consumption of shellfish contaminated with PTXs cannot be performed. This review gives a brief introduction to diarrhetic shellfish toxins, details the known toxicology and metabolism of PTXs in animals, and discusses known incidences of PTX poisoning in humans. (C) 2001 Elsevier Science Ltd. All rights reserved.

Routine ultrasound screening in diabetic pregnancies

Objectives To assess the detection rate of congenital fetal malformations and specific problems related to routine ultrasound screening in women with pre-existing diabetes. Methods A retrospective study was carried out to assess the performance of routine ultrasound screening in women with pre-existing diabetes (Types 1 and 2) within a tertiary institution. The incidence, type and risk factors for congenital fetal malformations were determined. The detection rate of fetal anomalies for diabetic women was compared with that for the low-risk population. Factors affecting these detection rates were evaluated. Results During the study period, 12 169 low-risk pregnant women and 130 women with pre-existing diabetes had routine ultrasound screening performed within the institution. A total of 10 major anomalies (7.7%) and three minor anomalies (2.3%) were present in the fetuses of the diabetic women. Central nervous system and cardiovascular system anomalies accounted for 60% of the major anomalies. Peri-conceptional hemoglobin A 1 c of more than 9% was associated with a high prevalence of major anomalies (14311000). Women who had fetuses with major anomalies bad a significantly higher incidence of obesity (78% vs. 37%; P < 0.05). Ultrasound examination of these diabetic pregnancies showed high incidences of suboptimal image quality (37%), incomplete examinations, and repeat examinations (17%). Compared to the 'low-risk' non-diabetic population from the same institution, the relative risk for a major congenital anomaly among the diabetic women was 5.9-fold higher (95% confidence interval, 2.9-11.9). The detection rate for major fetal anomalies was significantly lower for diabetic women (30% vs. 73%; P < 0.01), and the mean body mass index for the diabetic group was significantly higher (29 vs. 23 kg/m(2); P < 0.001). Conclusion The incidence of congenital anomalies is higher in diabetic pregnancies. Unfortunately, the detection rate for fetal anomalies by antenatal ultrasound scan was significantly, worse than that for the low-risk population. This is likely to be related to the maternal body habitus and unsatisfactory examinations. Methods to overcome these difficulties are discussed.

Chloroquine or sulfadoxine-pyrimethamine for the treatment of uncomplicated, Plasmodium falciparum malaria during an epidemic in Central Java, Indonesia

A recent malaria epidemic in the Menoreh Hills of Central Java has increased concern about the re-emergence of endemic malaria on Java, which threatens the island's 120 million residents. A 28-day, in-vivo test of the efficacy of treatment of malaria with antimalarial drugs was conducted among 16 7 villagers in the Menoreh Hills. The treatments investigated, chloroquine (CQ) and sulfadoxine pyrimethamine (SP), constitute, respectively, the first- and second-line treatments for uncomplicated malaria in Indonesia. The prevalence of malaria among 1389 residents screened prior to enrollment was 33%. Treatment outcomes were assessed by microscopical diagnoses, PCR-based confirmation of the diagnoses, measurement of the whole-blood concentrations of CQ and desethylchloroquine (DCQ), and identification of the Plasmodium falciparum genotypes. The 28-day cumulative incidences of therapeutic failure for CQ and SP were, respectively, 47% (N = 36) and 22% (N = 50) in the treatment of P. falciparum, and 18% (N = 77) and 67% (N = 6) in the treatment of P. vivax. Chloroquine was thus an ineffective therapy for P. falciparum malaria, and the presence of CQ-resistant P. vivax and SP-resistant P. falciparum will further compromise efforts to control resurgent malaria on Java.

NAD-glycohydrolase production and speA and speC distribution in group A streptococcus (GAS) isolates do not correlate with severe GAS diseases in the Australian population

Streptococcus pyogenes isolates from a tropical region and a subtropical region of Australia with high and low incidences of severe streptococcal diseases, respectively, were analyzed for speA, speB, and speC gene distributions and NAD-glycohydrolase expression. No direct correlation of these characteristics with a propensity to cause invasive diseases was observed.

On being loud and proud: Non-conformity and counter-conformity to group norms

Most experiments on conformity have been conducted in relation to judgments of physical reality; surprisingly few papers have experimentally examined the influence of group norms on social issues with a moral component. In response to this, participants were told that they were either in a minority or in a majority relative to their university group in terms of their attitudes toward recognition of gay couples in law (Expt 1: N = 205) and a government apology to Aborigines (Expt 2: N = 110). In both experiments, it was found that participants who had a weak moral basis for their attitude conformed to the group norm on private behaviours. In contrast, those who had a strong moral basis for their attitude showed non-conformity on private behaviours and counter-conformity on public behaviours. Incidences of nonconformity and counter-conformity are discussed with reference to theory and research on normative influence.

A comparison of the efficacy and safety of olanzapine versus haloperidol during transition from intramuscular to oral therapy

Background: Acutely agitated patients with schizophrenia who receive intramuscular (IM) medications typically are switched to oral (PO) antipsychotic maintenance therapy Objective: The goal of this study was to assess the efficacy and safety of olanzapine versus those of haloperidol during transition from IM to PO therapy We used additional data from a previously reported trial to test the hypothesis that the reduction in agitation achieved by IM olanzapine 10 mg or IM haloperidol 7.5 mg would be maintained following transition to 4 days of PO olanzapine or PO haloperidol (5-20 mg/d for both). We also hypothesized that olanzapine would maintain its more favorable extrapyramidal symptom (EPS) safety profile. Methods: This was a multinational (hospitals in 13 countries), double-blind, randomized, controlled trial. Acutely agitated inpatients with schizophrenia were treated with 1 to 3 IM injections of olanzapine 10 mg or haloperidol 7.5 mg over 24 hours and were entered into a 4-day PO treatment period with the same medication (5-20 mg/d for both). The primary efficacy measurement was reduction in agitation, as measured by the Positive and Negative Syndrome Scale-Excited Component (PANSS-EC) score. Adverse events and scores on EPS rating scales were assessed. Results: A total of 311 patients (204 men, 107 women; mean [SD] age, 38.2 [11.6] years) were enrolled (131, 126, and 54 patients in the olanzapine, haloperidol, and placebo groups, respectively). In all, 93.1% (122/131) of olanzapine-treated patients and 92.1% (116/126) of haloperidol-treated patients completed the IM period and entered the PO period; 85.5% (112/131) of olanzapine-treated patients and 84.1% (106/126) of haloperidol-treated patients completed the PO period. IM olanzapine and IM haloperidol effectively reduced agitation over 24 hours (mean [SD] PANSS-EC change, -7.1 [4.8] vs -6.7 [4.3], respectively). Reductions in agitation were sustained throughout the PO period with both study drugs (mean [SD] change from PO period baseline, -0.6 [4.8] vs -1.3 [4.4], respectively). During PO treatment, haloperidol-treated patients spontaneously reported significantly more acute dystonia than olanzapine-treated patients (4.3% [5/116] vs 0% [0/122], respectively; P = 0.026) and akathisia (5.2% [6/116] vs 0% [0/122], respectively; P = 0.013). Significantly more haloperidol-treated patients than olanzapine-treated patients met categorical criteria for treatment-emergent akathisia (18.5% [17/92] vs 6.5% [7/107], respectively; P = 0.015). Conclusions: In the acutely agitated patients with schizophrenia in this study, both IM olanzapine 10 mg and IM haloperidol 7.5 mg effectively reduced agitation over 24 hours. This alleviation of agitation was sustained following transition from IM therapy to 4 days of PO treatment (5-20 mg/d for both). During the 4 days of PO treatment, olanzapine-treated patients did not spontaneously report any incidences of acute dystonia, and olanzapine had a superior EPS safety profile to that of haloperidol. The combination of IM and PO olanzapine may help improve the treatment of acutely agitated patients with schizophrenia. Copyright (C) 2003 Excerpta Medica, Inc.

Intramuscular Olanzapine and Intramuscular Haloperidol in Acute Schizophrenia: Antipsychotic Efficacy and Extrapyramidal Safety During the First 24 Hours of Treatment

To determine the antipsychotic efficacy and extrapyramidal safety of intramuscular (IM) olanzapine and IM haloperidol during the first 24 hours of treatment of acute schizophrenia. Method: Patients (n = 311) with acute schizophrenia were randomly allocated (2:2: 1) to receive IM olanzapine (10.0 mg, n = 131), IM haloperidol (7.5 mg, n = 126), or IM placebo (n = 54). Results: After the first injection, IM olanzapine was comparable to IM haloperidol and superior to IM placebo for reducing mean change scores from baseline on the Brief Psychiatric Rating Scale (BRPS) Positive at 2 hours (-2.9 olanzapine, -2.7 haloperidol, and -1.5 placebo) and 24 hours (-2.8 olanzapine, -3.2 haloperidol, and -1.3 placebo); the BPRS Total at 2 hours (-14.2 olanzapine,-13.1 haloperidol, and -7.1 placebo) and 24 hours (-12.8 olanzapine, -12.9 haloperidol, and -6.2 placebo); and the Clinical Global Impressions (CGI) scale at 24 hours (-0.5 olanzapine, -0.5 haloperidol, and -0.1 placebo). Patients treated with IM olanzapine had significantly fewer incidences of treatment-emergent parkinsonism (4.3% olanzapine vs 13.3% haloperidol, P = 0.036), but not akathisia (1.1% olanzapine vs 6.5% haloperidol, P = 0.065), than did patients treated with IM haloperidol; they also required significantly less anticholinergic treatment (4.6% olanzapine vs 20.6% haloperidol, P < 0.001). Mean extrapyramidal symptoms (EPS) safety scores improved significantly from baseline during IM olanzapine treatment, compared with a general worsening during IM haloperidol treatment (Simpson-Angus Scale total score mean change: -0.61 olanzapine vs 0.70 haloperidol; P < 0.001; Barnes Akathisia Scale global score mean change: -0.27 olanzapine vs 0.01 haloperidol; P < 0.05). Conclusion: IM olanzapine was comparable to IM haloperidol for reducing the symptoms of acute schizophrenia during the first 24 hours of treatment, the efficacy of both being evident within 2 hours after the first injection. In general, more EPS were observed during treatment with IM haloperidol than with IM olanzapine.

Cell death and degeneration in the symbiotic dinoflagellates of the coral Stylophora pistillata during bleaching

Rising sea temperatures are increasing the incidences of mass coral bleaching (the dissociation of the coral-algal symbiosis) and coral mortality. In this study, the effects of bleaching (induced by elevated light and temperature) on the condition of symbiotic dinoflagellates (Symbiodinium sp.) within the tissue of the hard coral Stylophora pistillata (Esper) were assessed using a suite of techniques. Bleaching of S. pistillata was accompanied by declines in the maximum potential quantum yield of photosynthesis (F-v/F-m, measured using pulse amplitude modulated [PAM] fluorometry), an increase in the number of Sytox-green-stained algae (indicating compromised algal membrane integrity and cell death), an increase in 2',7'-dichlorodihydrofluroscein diacetate (H(2)DCFDA)stained algae (indicating increased oxidative stress), as well as ultrastructural changes (vacuolisation, losses of chlorophyll, and an increase in accumulation bodies). Algae expelled from S. pistillata exhibited a complete disorganisation of cellular contents; expelled cells contained only amorphous material. In situ samples taken during a natural mass coral bleaching event on the Great Barrier Reef in February 2002 also revealed a high number of Sytox-labelled algae cells in symbio. Dinoflagellate degeneration during bleaching seems to be similar to the changes resulting from senescence-phase cell death in cultured algae. These data support a role for oxidative stress in the mechanism of coral bleaching and highlight the importance of algal degeneration during the bleaching of a reef coral.

Randomized, controlled trial of topical exit-site application of honey (Medihoney) versus Mupirocin for the prevention of catheter-associated infections in hemodialysis patients

The clinical usefulness of hemodialysis catheters is limited by increased infectious morbidity and mortality. Topical antiseptic agents, such as mupirocin, are effective at reducing this risk but have been reported to select for antibiotic-resistant strains. The aim of the present study was to determine the efficacy and the safety of exit-site application of a standardized antibacterial honey versus mupirocin in preventing catheter-associated infections. A randomized, controlled trial was performed comparing the effect of thrice-weekly exit-site application of Medihoney versus mupirocin on infection rates in patients who were receiving hemodialysis via tunneled, cuffed central venous catheters. A total of 101 patients were enrolled. The incidences of catheter-associated bacteremias in honey-treated (n = 51) and mupirocin-treated (n = 50) patients were comparable (0.97 versus 0.85 episodes per 1000 catheter-days, respectively; NS). On Cox proportional hazards model analysis, the use of honey was not significantly associated with bacteremia-free survival (unadjusted hazard ratio, 0.94; 95% confidence interval, 0.27 to 3.24; P = 0.92). No exit-site infections occurred. During the study period, 2% of staphylococcal isolates within the hospital were mupirocin resistant. Thrice-weekly application of standardized antibacterial honey to hemodialysis catheter exit sites was safe, cheap, and effective and resulted in a comparable rate of catheter-associated infection to that obtained with mupirocin (although the study was not adequately powered to assess therapeutic equivalence). The effectiveness of honey against antibiotic-resistant microorganisms and its low likelihood of selecting for further resistant strains suggest that this agent may represent a satisfactory alternative means of chemoprophylaxis in patients with central venous catheters.

Clinical tests of musculoskeletal dysfunction in the diagnosis of cervicogenic headache

Persistent intermittent headache is a common disorder and is often accompanied by neck aching or stiffness, which could infer a cervical contribution to headache. However, the incidence of cervicogenic headache is estimated to be 14-18% of all chronic headaches, highlighting the need for clear criterion of cervical musculoskeletal impairment to identify cervicogenic headache sufferers who may benefit from treatments such as manual therapy. This study examined the presence of cervical musculoskeletal impairment in 77 subjects, 27 with cervicogenic headache, 25 with migraine with aura and 25 control subjects. Assessments included a photographic measure of posture, range of movement, cervical manual examination, pressure pain thresholds, muscle length, performance in the cranio-cervical flexion test and cervical kinaesthetic sense. The results indicated that when compared to the migraine with aura and control groups who scored similarly in the tests, the cervicogenic headache group had less range of cervical flexion/extension (P = 0.048) and significantly higher incidences of painful upper cervical joint dysfunction assessed by manual examination (all P < 0.05) and muscle tightness (P < 0.05). Sternocleidomastoid normalized EMG values were higher in the latter three stages of the cranio-cervical flexion test although they failed to reach significance. There were no between group differences for other measures. A discriminant analysis revealed that manual examination could discriminate the cervicogenic headache group from the other subjects (migraine with aura and control subjects combined) with an 80% sensitivity. (C) 2005 Elsevier Ltd. All rights reserved.

The importance of host ecology in thelastomatoid (Nematoda : Oxyurida) host specificity

An experimental investigation of host specificity within the Thelastomatoidea is presented by means of a comparison of the thelastomatoids of two panesthiine cockroaches, Panesthia cribrata and R tryoni tryoni, with those of other log-dwelling arthropods and those of leaf litter dwelling arthropods found near by. 145 log-dwelling and leaf-litter dwelling arthropods, representing adjacent ecological niches, were collected from Lamington National Park, Queensland, Australia. A high degree of thelastomatoid species sharing (19 incidences from 26 specimens) occurs between log-dwelling arthropods and the two cockroach species. No overlap in thelastomatoid fauna was observed between the log dwelling and leaf-litter dwelling groups. Our results suggest that host specificity of thelastomatoids is largely dictated by host ecology. (c) 2006 Elsevier Ireland Ltd. All rights reserved.

Graduate overeducation and its effects among recently arrived immigrants to Australia: A longitudinal survey

There is increasing importance attached to skill-based immigration in many countries including Australia. This paper investigates the incidences, determinants, and returns to graduate overeducation among tertiary qualified immigrants during the early phase of their settlement in Australia. We place particular emphasis on visa categories and region of origin. As expected, those on visas with higher skill requirements perform better in the labour market. The bulk of these are immigrants from English Speaking Backgrounds (ESB). Non-English Speaking Background (NESB) immigrants, on the other hand, have higher and persistent rates of overeducation. The wage returns to required and surplus education match the stylized facts of overeducation for ESB and Other NESB immigrants while Asian NESB immigrants receive no return to surplus education. Thus, the results suggest that NESB graduate immigrants are a heterogeneous group, with Asian graduate immigrants facing greater assimilation hurdles in the Australian labour market.