PAI-1 protein is a key molecular effector in the transition from normal to PTSD-like fear memory.

Moderate stress increases memory and facilitates adaptation. In contrast, intense stress can induce pathological memories as observed in post-traumatic stress disorders (PTSD). A shift in the balance between the expression of tPA and PAI-1 proteins is responsible for this transition. In conditions of moderate stress, glucocorticoid hormones increase the expression of the tPA protein in the hippocampal brain region which by triggering the Erk1/2MAPK signaling cascade strengthens memory. When stress is particularly intense, very high levels of glucocorticoid hormones then increase the production of PAI-1 protein, which by blocking the activity of tPA induces PTSD-like memories. PAI-1 levels after trauma could be a predictive biomarker of the subsequent appearance of PTSD and pharmacological inhibition of PAI-1 activity a new therapeutic approach to this debilitating condition.

Can Local Enhancement in Earthworms Affect the Outcome of the Standard Earthworm Avoidance Test?

Earthworms exhibit clumping behaviour in and out of the soil. However, it remains unknown if such social behaviour ultimately influences the outcome of ecotoxicological experiments in the laboratory. We performed several overnight avoidance tests to determine whether social behaviour (i.e., local enhancement) is a factor in pollution avoidance behaviour in the earthworm Eisenia fetida. The results showed that there was no clear influence of social behaviour on the choice or avoidance of Cd contaminated soils, although we suspect that 50 mg Cd/kg might not have been high enough to elicit a significant avoidance response. Nevertheless, when offered a choice between clean undisturbed soil and previously inhabited soil, the worms preferred the previously inhabited soil (p < 0.01). While the level of metal pollution investigated in this study did not disrupt or help predict social dynamics, local enhancement, perhaps driven by some sort of habitat imprinting, was successfully documented in Eisenia fetida.

High load of hepatitis E viral RNA in pork livers but absence in pork muscle at French slaughterhouses.

Pork ham muscle can be contaminated with HEV via blood vessels during viremia and represents a possible source of human contamination via the consumption of dried ham. This study evaluated the prevalence of HEV RNA in pork ham muscles and pork livers at slaughterhouses. Serology was determined on the corresponding serum samples. The apparent individual seroprevalence rate in the 49 pig farms studied was 59% [55.5%-61.4%]. None of the 1134 ham muscles tested was positive for the presence of HEV. HEV prevalence in paired liver samples was 2.8% with a level of contamination of up to 1.46 108copies/g. Sequences of viral strains isolated from positive livers belonged to genotype 3 and subtypes 3c, 3e, 3f and 3j. Our results confirmed that raw pork liver food products are a source of risk for humans but they also showed that there is a limited risk of human infection by HEV through the consumption of ham muscle.

Reduced susceptibilities to biocides and resistance to antibiotics in food-associated bacteria following exposure to quaternary ammonium compounds.

AIMS: Our aim was to assess the effects of step-wise exposure to didecyl dimethyl ammonium chloride (DDAC) on the antimicrobial (antibiotics and biocides) susceptibilities of food-associated bacterial strains. METHODS AND RESULTS: Adaptive responses of bacterial strains were investigated by exposing the strains daily to increasing subinhibitory concentrations of DDAC for 7 days. Following adaptation to DDAC, a threefold increase in the minimum inhibitory concentration (MIC) values for this biocide was observed in 48% of the Escherichia coli and Listeria monocytogenes strains, and 3% of the Salmonella strains. Reduced susceptibility to other biocides was found with the most important increase in MIC for benzalkonium chloride (BC) and a commercial biocide formulation (Galox Horizon) containing DDAC and glutaraldehyde, for all species except Salmonella. Increase in antibiotic MIC values was more pronounced in E. coli in terms of antibiotic numbers and of magnitude (from 4- to 32-fold increase) and, to a lesser extent, in Salmonella strains. Most of these strains had acquired resistance to ampicillin, cefotaxime, ceftazidime, chloramphenicol and ciprofloxacin. CONCLUSIONS: The effects of exposure to DDAC on biocides and antibiotics susceptibilities depend upon the bacteria species. SIGNIFICANCE AND IMPACT OF THE STUDY: Extensive use of DDAC at subinhibitory concentrations may lead to the development of antibiotic-resistant bacteria and may represent a public health issue.

BDNF-TrkB signaling through Erk1/2 MAPK phosphorylation mediates the enhancement of fear memory induced by glucocorticoids.

Activation of glucocorticoid receptors (GR) by glucocorticoid hormones (GC) enhances contextual fear memories through the activation of the Erk1/2(MAPK) signaling pathway. However, the molecular mechanism mediating this effect of GC remains unknown. Here we used complementary molecular and behavioral approaches in mice and rats and in genetically modified mice in which the GR was conditionally deleted (GR(NesCre)). We identified the tPA-BDNF-TrkB signaling pathway as the upstream molecular effectors of GR-mediated phosphorylation of Erk1/2(MAPK) responsible for the enhancement of contextual fear memory. These findings complete our knowledge of the molecular cascade through which GC enhance contextual fear memory and highlight the role of tPA-BDNF-TrkB-Erk1/2(MAPK) signaling pathways as one of the core effectors of stress-related effects of GC.

[Risk factors of nasogastric tube placement after elective colorectal surgery included in a rehabilitation programme: a multivariate analysis]. / Facteurs de risque de pose de sonde gastrique en chirurgie colorectale programmée, dans le cadre d'un programme de réhabilitation postopératoire: une analyse multivariée.

OBJECTIVE: Nasogastric tube placement (NTP) is no more systematically recommended in patients scheduled for elective colorectal surgery but could be necessary in case of postoperative vomiting. The aim of this study was to determine independent risk factors for NTP after colorectal surgery. PATIENTS AND METHODS: We performed an observational study including 290 patients scheduled for elective colorectal surgery included in an enhanced recovery programme: immunonutrition, thoracic epidural analgesia, antiemetic prophylaxis, respiratory physiotherapy, absence of NT and drainage, forced mobilization and oral nutrition. The main outcome was the occurrence of vomiting requiring NTP. Univariate analysis included: age, sex, BMI, American Society of Anesthesiologist Physical Status Classification System (ASA), duration of surgery, epidural analgesia, and mobilization, intraoperative fluid, temperature, laparotomy, use of droperidol, parenteral nutrition, stoma, diabetes, hypertension or coronary disease, COPD, type of surgery. A logistic regression was performed to determine independent risk factors of NTP. RESULTS: Among the 290 patients included, 277 were analyzed. The incidence of NTP was 10.5% (95%CI [7.4-14.6%]). Univariate analysis documented BMI, low temperature in PACU (<35°C), ASA scores, duration of surgery and epidural analgesia, rectal and sigmoid resections, diabetes, transfusion, no use of droperidol, duration of mobilization, conversion to laparotomy. Three independent risk factors were associated with NTP: temperature in SSPI<35.5°C (OR: 14.49; IC95% [4.52-45.45], P<0.0001), BMI<21kg/m(2) (8.40; [1.99-35.71], P=0.0038) and lack of postoperative droperidol administration (3.37 [1.02-11.39], P=0.04). CONCLUSIONS: After colorectal surgery tolerance to rapid oral feeding is impaired by denutrition and postoperative hypothermia. The combined used of postoperative droperidol should also be considered to avoid postoperative NTP.

Methicillin-resistant Staphylococcus aureus ST398 contamination and transmission in pigs after a low dose inoculation.

AIMS: Methicillin-resistant Staphylococcus aureus (MRSA) ST398 has recently been described as a zoonotic agent. Its transmission between animals seems to be a pivotal factor in its emergence and dissemination. This experimental trial was performed to describe MRSA ST398 contamination and transmission in pigs after a low dose inoculation. METHODS AND RESULTS: Twelve specific pathogen-free (SPF) pigs were randomly divided between two separate pens. Three pigs in each pen received a nasal inoculation of 2 × 10(4) colony-forming units per animal, and three naïve pigs were left in contact with them. Every 2 days and at necropsy, different samples were screened for MRSA. It was detected in nasal swabs from five inoculated and three naïve contact pigs, as early as 1 day after inoculation. MRSA was also found in environmental wipes but never in faecal samples. At necropsy, MRSA was detected in the lymph nodes of two contact pigs and in the tonsils and lymph nodes of three inoculated pigs. Twelve other SPF pigs were included as negative control in a separate room. CONCLUSION: This experiment showed that inoculation of a low dose of MRSA ST398 could lead to the horizontal transmission of the bacterium between pigs, the contamination of mandibular lymph nodes and the contamination of the environment without faecal carriage. SIGNIFICANCE AND IMPACT OF THE STUDY: The minimal inoculated dose via nasal route to observe transmission of MRSA ST398 between pigs is equal or lower to 2 × 10(4) colony-forming units per animal, and faecal excretion seems not to be a necessary condition for horizontal transmission.

Comparison between ultrasound-guided transversus abdominis plane and conventional ilioinguinal/iliohypogastric nerve blocks for day-case open inguinal hernia repair.

BACKGROUND: Transversus abdominis plane (TAP) block has been reported to provide effective analgesia after lower abdominal surgery, but there are few data comparing ilioinguinal/iliohypogastric nerve (IHN) block with ultrasound-guided TAP block in patients undergoing inguinal hernia repair. METHODS: Two hundred and seventy-three patients undergoing day-case open inguinal hernia repair with a mesh were randomly allocated to receive either ultrasound-guided TAP block or blind IHN block with levobupivacaine 0.5%, before surgery. Patients were monitored for visual analogue scale (VAS) scores at rest (in the post-anaesthesia care unit, and at 4 and 12 h) and at rest and during movement (at 24, 48 h, 3 and 6 months). Pain at 6 months was also assessed using the DN4 questionnaire for neuropathic pain. RESULTS: Median VAS pain scores at rest were lower in the ultrasound-guided TAP group at 4 h (11 vs 15, P=0.04), at 12 h (20 vs 30, P=0.0014), and at 24 h (29 vs 33, P=0.013). Pain after the first 24 h, at 3 and 6 months after surgery, and DN4 scores were similar in both groups (P=NS). The proportion of patients with VAS >40 mm on movement at 6 months was comparable {18.2% [95% CI (12.2-26.1%)] vs 22.4% (15.8-30.6%) in the TAP and IHN groups, respectively, P=0.8}. Postoperative morphine requirements were lower during the first 24 h in the TAP block group (P=0.03). CONCLUSIONS: Ultrasound-guided TAP block provided better pain control than 'blind' IHN block after inguinal hernia repair but did not prevent the occurrence of chronic pain.

Flexibility of experimental alumina/feldspar and SR ADORO dental composites.

INTRODUCTION: Flexure of a dental composite can be detrimental to the success of a restoration. Flexibility considerations are thus important when comparing dental materials to optimize the success of resin restorations. AIMS AND OBJECTIVES: Flexibility of 5.6 x 18.0 x 2.0 mm3 experimental alumina/feldspar and SR ADORO dental composites specimens were compared. It was hypothesized that alumina/feldspar composites would be less flexible under a load than SR ADORO composites and that the flexibility would decrease significantly as the feldspar content was increased. METHODS: Alumina was chemically sintered or bonded with 40%, 50% and 60% feldspar mass, silanized and infiltrated with urethane dimethacrylate (UDMA) to prepare the alumina/feldspar dental restorative composite specimens. Three point bending tests were performed in the Instron 44 machine for flexural comparison to SR ADORO. RESULTS AND CONCLUSIONS: The alumina/feldspar specimens showed lower flexibility (mm displacement) than SR ADORO (p < 0.05). Accurate flexibility comparisons were performed with 5.6 x 18.0 x 2.0 mm3 specimens. Flexibility comparisons performed with 5.6 x 18.0 x 2.0 mm3 specimens indicated that experimental alumina/feldspar dental composites may provide added marginal seal benefit. However confirmation via in vivo function of alumina/feldspar dental composites is recommended.

The enhancement of stress-related memory by glucocorticoids depends on synapsin-Ia/Ib.

The activation of glucocorticoid receptors (GR) by glucocorticoids increases stress-related memory through the activation of the MAPK signaling pathway and the downstream transcription factor Egr-1. Here, using converging in vitro and in vivo approaches, respectively, GR-expressing cell lines, culture of hippocampal neurons, and GR genetically modified mice (GR(NesCre)), we identified synapsin-Ia/Ib as one of the effectors of the glucocorticoid signaling cascade. Stress and glucocorticoid-induced activation of the GR modulate synapsin-Ia/Ib through two complementary mechanisms. First, glucocorticoids driving Egr-1 expression increase the expression of synapsin-Ia/Ib, and second, glucocorticoids driving MAPK activation increase its phosphorylation. Finally, we showed that blocking fucosylation of synapsin-Ia/Ib in the hippocampus inhibits its expression and prevents the glucocorticoid-mediated increase in stress-related memory. In conclusion, our data provide a complete molecular pathway (GR/Egr-1/MAPK/Syn-Ia/Ib) through which stress and glucocorticoids enhance the memory of stress-related events and highlight the function of synapsin-Ia/Ib as molecular effector of the behavioral effects of stress.

A retrospective review of trends and clinical characteristics of methamphetamine-related acute psychiatric admissions in a South African context.

OBJECTIVE: Epidemiological studies indicate that methamphetamine (MA) abuse poses a major challenge to health in the Western Cape. The objectives of this study were to retrospectively assess the trends, clinical characteristics and treatment demand of MA-related admissions to a psychiatric ward in this region. METHOD: The clinical records of patients admitted to an acute psychiatric admission ward at Tygerberg Hospital from 1 January 2002 to 30 June 2002 and 1 January 2006 to 30 June 2006, were retrospectively reviewed. Admission numbers including those of adolescent and adult substance users were compared for both study periods. Study samples comparing demographic profile, admission status, length of stay, psychopathology, treatment requirements and referral pattern to other disciplines between MA users and non-users were collected for the 2006 period. RESULTS: There was a significant (p <0.01) increase in adolescent substance user admissions between the study periods. A significant (p <0.01) increase in adolescent and adult MA user admissions was also noted. MA users were significantly (p = 0.04) younger than non-MA users, whilst the former presented mainly with psychotic features associated with aggression, requiring involuntary admission of an average of 8 weeks. MA users required significantly (p = 0.007) more benzodiazepines compared to non-MA users. CONCLUSION: Although MA use is relatively recent to the Western Cape, its adverse psychiatric effects and consequences have become a major challenge. These effects in both adolescent and adult patient populations and the associated impact on psychiatric services demand urgent intervention strategies as well as prospective study.

Effect of short-term treatment with meloxicam and pimobendan on the renal function in healthy beagle dogs.

The aim of the study was to investigate the renal function in clinically normal dogs receiving meloxicam and pimobendan alone or in combination. Ten adult female beagle dogs were administered the treatment for 7 days in a randomized crossover trial (control/meloxicam/pimobendan/meloxicam and pimobendan). Renal function was assessed by blood urea, creatinine, sodium, potassium and chloride concentrations and by glomerular filtration rate, measured by means of renal scintigraphy [renal uptake of (99m)Tc-diethylenetriaminepentacetic acid (DTPA)] and plasma clearance of (99m)Tc-DTPA. As compared with the control group, renal uptake and plasma clearance of (99m)Tc-DTPA were not significantly modified after a 7-day period of treatment with meloxicam or pimobendan alone, or meloxicam and pimobendan in combination. Furthermore, urea, creatinine, sodium, potassium and chloride levels in the serum of the dogs during the 7-day period treatment were not significantly modified in relation to the treatments. It was therefore concluded that meloxicam and pimobendan alone or in combination did not alter renal function in healthy dogs.

Wear and flexural strength comparisons of alumina/feldspar resin infiltrated dental composites.

INTRODUCTION: Incorporating a feldspar chemical bond between alumina filler particles is expected to increase the wear-resistant and flexural strength properties. AIMS AND OBJECTIVES: An investigation was carried out to evaluate the influence of the feldspar chemical bonding between alumina filler particles on wear and flexural strength of experimental alumina/feldspar dental composites. It was hypothesized that wear resistance and flexural strength would be significantly increased with increased feldspar mass. METHODS: Alumina was chemically sintered and bonded with 30% and 60% feldspar mass, silanized and infiltrated with UDMA resin to prepare the dental restorative composite material. RESULTS AND CONCLUSIONS: Higher wear-resistant characteristics resulted with increased feldspar mass of up to 60% (p < 0.05). Higher flexural strength characteristics resulted as the feldspar mass was increased up to 60% (p > 0.05). Feldspar chemical bonding between the alumina particles may improve on the wear-resistance and flexural strength of alumina/feldspar composites.

Antipsychotic prescription patterns in Xhosa patients with schizophrenia or schizoaffective disorder.

OBJECTIVE: To examine the degree to which South African physicians use similar treatment guidelines in their prescription of antipsychotic medication. METHOD: Data on the prescriptions for Xhosa patients with schizophrenia and schizoaffective disorder were retrospectively examined to investigate differences between three catchment areas in the Western Cape, especially in terms of clozapine use. RESULTS: There was an overall low rate (10.0%) of clozapine use and a relatively high occurrence of polypharmacy (28.6% of 510 patients). There were statistically significant differences between the three catchment areas in terms of clozapine (p=0.002) and haloperidol (p=0.001) use. Valkenberg hospital had the highest number of clozapine prescriptions and the lowest of haloperidol. Prescriptions of depot antipsychotics did not differ between catchment areas. CONCLUSION: Discrepancies in antipsychotic medicine prescription patterns were evident between the examined hospitals. It is becoming paramount for practical implementation of guidelines to be improved in South Africa to address, e.g., low clozapine use and the high frequency of polypharmacy.

Dental composite materials: highlighting the problem of wear for posterior restorations.

Manufacturers of dental composites promote their products as having ideal wear resistant characteristics. Evaluation of the problems that persist with wear of dental composites is made. Recommendations for further research involving wear resistance of dental composite materials are provided. This article provides a review of English, peer-reviewed literature involving wear resistance of dental composite materials conducted through ScienceDirect and hand searched data bases between 1994 and 2006.

Acute extradural haematoma in the elderly.

The world's population of persons over 65 years of age (elderly) is increasing. Acute extradural haematoma (AEDH) in the elderly is rare. There has not been a publication dedicated solely to the evaluation of AEDH in the elderly. We undertook this study in order to establish a clinical profile in this important subgroup. It took the form of a retrospective evaluation of the in-patient charts of elderly patients with AEDH, performed over a 23-year period (1983-2005) at a single institution. Of 3249 patients with AEDH, 32 (<1%) were defined as elderly. Assault was the commonest causative factor (56%), followed by falls (25%) and motor vehicle accidents (19%). Eight patients died (25% mortality). Only a third of patients, (34%) made a good outcome, the majority of these were assault victims. No patient in coma, or over 75 years made a good outcome. The prognosis of elderly patients with AEDH is poor. Conservative treatment for comatose patients and the over 75s is justified.

[Cross-cultural study on loneliness of students at the University of the Free State]. / 'n Kruiskulturele ondersoek na eensaamheid onder studente van die Universiteit van die Vrystaat.

Many young people today are lonely and hopeless, and feel that life has no meaning. The existing literature indicates that this phenomenon is taking on near-epidemic proportions in industrialised Western countries. A considerable amount of cross-cultural investigations have already been conducted overseas between different population groups, in order to determine what the causes of this phenomenon are and whether culture plays an important role in the development of loneliness. As far as this type of research is concerned South Africa is currently far behind the rest of the world. Serious efforts shall have to be made to determine whether loneliness is taking on the same proportions locally and if certain population groups are more vulnerable than others, because it could have far-reaching consequences on their physical as well as psychological health. South Africa has a rich population variety which could enable researchers to investigate emotional constructs like loneliness that could contribute to the unravelling of this multifaceted phenomenon. The purpose of this investigation was therefore to determine whether students from different cultural backgrounds at the University of the Free State differ from each other, as far as their experience of loneliness is concerned. Questionnaires were distributed among students and 270 respondents, of which 122 were white and 148 black, took part in this study. A factorial analysis of variance was applied on the data, with loneliness as dependent variable, and cultural background, gender and age as independent variables. The results firstly show that cultural background is a very important variable as far as loneliness is concerned. Black students are significantly more lonely than white students while no gender and age differences between the groups were found.

Morality as a predictor of loneliness: a cross-cultural study.

Loneliness is currently regarded as one of the most common and prevalent problems experienced by adolescents, and it is also observed as a painful, unpleasant and negative experience. South African adolescents also have to face and cope with this predicament daily. The main objective of this study was to establish the perception of adolescents of different cultures regarding loneliness and morality and to investigate the relationship between them. It was also determined which of the independent variables, namely morality, gender, age, mother tongue and ethnicity, contributed significantly to the prediction of loneliness. A total of 714 adolescents from three different secondary schools in the greater Bloemfontein area between the ages of 13 and 17 were selected. Adolescents were used because they are increasingly being confronted with moral issues and because loneliness occurs more commonly during adolescence. The focus was on three ethnic groups, namely Coloured, black and white. Three different questionnaires, namely the Le Roux Loneliness Scale, the Morally Debatable Behaviours Scale and a biographical questionnaire were completed to obtain the necessary data. A significant inverse correlation between loneliness and morality was determined, while morality was identified as the best predictor of loneliness.