Cohort trends in age of initiation to heroin use

This paper examines gender differences and trends over time in the age of initiation to heroin use. Data from two large surveys: the Sydney component of the ANAIDUS, conducted in 1989, and the ASHIDU, conducted in 1994, were used to examine this issue. Together, these studies contained information on 1,292 individuals who identified themselves as heroin users. Results indicated that, while there were no significant gender differences in age of initiation to heroin use, there was a significant (p < 0.001) time trend in the mean age at which heroin was first used. Specifically, the mean age of first heroin use among individuals born during the interval 1940-1949 was 20.5 years while among those born during 1970-1979 the mean age of first heroin use was 16.5 years. These findings were confirmed by analyses of the National Household Survey. Further analysis of the ASHIDU data indicated that younger age of initiation to heroin use was associated with polydrug use, overdose and crime after the effects of duration of heroin use had been statistically controlled. These findings suggest that there has been both an increase in the willingness of young people to experiment with heroin and an increased availability of the drug over this time. In combination with evidence that there has been an increase in the amount of heroin being imported into Australia, and an increased demand for treatment for opiate dependence, these data suggest that Australia is experiencing an increase in the use of heroin, particularly among youth.

The velocity of probability transport in quantum mechanics

In his study of the 'time of arrival' problem in the nonrelativistic quantum mechanics of a single particle, Allcock [1] noted that the direction of the probability flux vector is not necessarily the same as that of the mean momentum of a wave packet, even when the packet is composed entirely of plane waves with a common direction of momentum. Packets can be constructed, for example for a particle moving under a constant force, in which probability flows for a finite time in the opposite direction to the momentum. A similar phenomenon occurs for the Dirac electron. The maximum amount of probabilitiy backflow which can occur over a given time interval can be calculated in each case.

Community care and criminal offending in schizophrenia

Background The introduction of community care in psychiatry is widely thought to have resulted in more offending among the seriously mentally ill. This view affects public policy towards and public perceptions of such people. We investigated the association between the introduction of community care and the pattern of offending in patients with schizophrenia in Victoria, Australia. Methods We established patterns of offending from criminal records in two groups of patients with schizophrenia over their lifetime to date and in the 10 years after their first hospital admission. One group was first admitted in 1975 before major deinstitutionalisation in Victoria, the second group in 1985 when community care was becoming the norm. Each patient was matched to a control, by age, sex, and place of residence to allow for changing patterns of offending over time in the wider community. Findings Compared with controls, significantly more of those with schizophrenia were convicted at least once for ail categories of criminal offending except sexual offences (relative risk of offending in 1975=3.5 [95% CI 2.0-5.5), p=0.001, in 1985=3.0 [1.9-4.9], p=0.001). Among men, more offences were committed in the 1985 group than the 1975 group, but this was matched by a similar increase in convictions among the community controls. Those with schizophrenia who had also received treatment for substance abuse accounted for a disproportionate amount of offending. Analysis of admission data for the patients and the total population of admissions with schizophrenia showed that although there had been an increase of 74 days per annum spent in the community for each of the study population as a whole, first admissions spent only 1 more day in the community in 1985 compared with 1975. Interpretation Increased rates in criminal conviction for those with schizophrenia over the last 20 years are consistent with change in the pattern of offending in the general community. Deinstitutionalisation does not adequately explain such change. Mental-health services should aim to reduce the raised rates of criminal offending associated with schizophrenia, but turning the clock back on community care is unlikely to contribute towards any positive outcome.

Finite element modeling of fluid-rock interaction problems in pore-fluid saturated hydrothermal/sedimentary basins

In order to use the finite element method for solving fluid-rock interaction problems in pore-fluid saturated hydrothermal/sedimentary basins effectively and efficiently, we have presented, in this paper, the new concept and numerical algorithms to deal with the fundamental issues associated with the fluid-rock interaction problems. These fundamental issues are often overlooked by some purely numerical modelers. (1) Since the fluid-rock interaction problem involves heterogeneous chemical reactions between reactive aqueous chemical species in the pore-fluid and solid minerals in the rock masses, it is necessary to develop the new concept of the generalized concentration of a solid mineral, so that two types of reactive mass transport equations, namely, the conventional mass transport equation for the aqueous chemical species in the pore-fluid and the degenerated mass transport equation for the solid minerals in the rock mass, can be solved simultaneously in computation. (2) Since the reaction area between the pore-fluid and mineral surfaces is basically a function of the generalized concentration of the solid mineral, there is a definite need to appropriately consider the dependence of the dissolution rate of a dissolving mineral on its generalized concentration in the numerical analysis. (3) Considering the direct consequence of the porosity evolution with time in the transient analysis of fluid-rock interaction problems; we have proposed the term splitting algorithm and the concept of the equivalent source/sink terms in mass transport equations so that the problem of variable mesh Peclet number and Courant number has been successfully converted into the problem of constant mesh Peclet and Courant numbers. The numerical results from an application example have demonstrated the usefulness of the proposed concepts and the robustness of the proposed numerical algorithms in dealing with fluid-rock interaction problems in pore-fluid saturated hydrothermal/sedimentary basins. (C) 2001 Elsevier Science B.V. All rights reserved.

Mutant GABA(A) receptor gamma 2-subunit in childhood absence epilepsy and febrile seizures

Epilepsies affect at least 2% of the population at some time in life, and many forms have genetic determinants(1,2). We have found a mutation in a gene encoding a GABA, receptor subunit in a large family with epilepsy. The two main phenotypes were childhood absence epilepsy (CAE) and febrile seizures (FS), There is a recognized genetic: relationship between FS and CAE, yet the two syndromes have different ages of onset, and the physiology of absences and convulsions is distinct. This suggests the mutation has age-dependent effects on different neuronal networks that influence the expression of these clinically distinct, but genetically related, epilepsy phenotypes. We found that the mutation in GABRG2 (encoding the gamma2-subunit) abolished in vitro sensitivity to diazepam, raising the possibility that endozepines do in fact exist and have a physiological role in preventing seizures.

Finite element modelling of reactive fluids mixing and mineralization in pore-fluid saturated hydrothermal/sedimentary basins

We present the finite element simulations of reactive mineral carrying fluids mixing and mineralization in pore-fluid saturated hydrothermal/sedimentary basins. In particular we explore the mixing of reactive sulfide and sulfate fluids and the relevant patterns of mineralization for Load, zinc and iron minerals in the regime of temperature-gradient-driven convective flow. Since the mineralization and ore body formation may last quite a long period of time in a hydrothermal basin, it is commonly assumed that, in the geochemistry, the solutions of minerals are in an equilibrium state or near an equilibrium state. Therefore, the mineralization rate of a particular kind of mineral can be expressed as the product of the pore-fluid velocity and the equilibrium concentration of this particular kind of mineral Using the present mineralization rate of a mineral, the potential of the modern mineralization theory is illustrated by means of finite element studies related to reactive mineral-carrying fluids mixing problems in materially homogeneous and inhomogeneous porous rock basins.

Platinum nanoparticles embledded in layer-by-layer films from SnO2/polyallylamine for ethanol electrooxidation

Self-assembled films from SnO2 and polyallylamine (PAH) were deposited on gold via ionic attraction by the layer-by-layer(LbL) method. The modified electrodes were immersed into a H2PtCl6 solution, a current of 100 mu A was applied, and different electrodeposition times were used. The SnO2/PAH layers served as templates to yield metallic platinum with different particle sizes. The scanning tunnel microscopy images show that the particle size increases as a function of electrodeposition time. The potentiodynamic profile of the electrodes changes as a function of the electrodeposition time in 0.5 mol L-1 H2SO4, at a sweeping rate of 50mVs(-1). Oxygen-like species are formed at less positive potentials for the Pt-SnO2/PAH film in the case of the smallest platinum particles. Electrochemical impedance spectroscopy measurements in acid medium at 0.7 V show that the charge transfer resistance normalized by the exposed platinum area is 750 times greater for platinum electrode (300 k Omega cm(2)) compared with the Pt-SnO2/PAH film with 1 min of electrodeposition (0.4 k Omega cm(2)). According to the Langmuir-Hinshelwood bifunctional mechanism, the high degree of coverage with oxygen-like species on the platinum nanoparticles is responsible for the electrocatalytic activity of the Pt-SnO2/PAH concerning ethanol electrooxidation. With these features, this Pt-SnO2/PAH film may be grown on a proton exchange membrane (PEM) in direct ethanol fuel cells (DEFC). (c) 2008 Elsevier B.V. All rights reserved.

Dormancy release in Australian fire ephemeral seeds during burial increases germination response to smoke water or heat

Fire ephemerals are short-lived plants that primarily germinate after fire. Fresh and laboratory-stored seeds are difficult to germinate ex situ, even in response to fire-related cues such as heat and smoke. Seeds of eight Australian fire ephemeral species were buried in unburnt and recently burnt sites of natural bushland during autumn. Seeds were exhumed after 6 and 12 months and incubated in water and smoke water, either with or without a heat treatment at 70 degrees C for 1 h. Generally, germination did not increase after 6 months of burial, but after 12 months of burial germination was enhanced in seven of the eight species. Actinotus leucocephalus produced higher germination following 12 months of burial without any further treatment, and smoke water and heat further improved germination. The four Gyrostemonaceae species, Codonocarpus cotinifolius, Gyrostemon racemiger, Gyrostemon ramulosus and Tersonia cyathiflora, only germinated in the presence of smoke water, and their germination was enhanced by burial. Burial improved germination in response to a heat treatment in Grevillea scapigera and Alyogyne huegelii seeds, but did not enhance Alyogyne hakeifolia germination. During concurrent dry laboratory storage of seeds at 15 degrees C, only Actinotus leucocephalus produced increased germination in response to smoke water and heat over time. In summary, soil burial can alter the dormancy status of a number of Australian fire ephemeral seeds, rendering them more responsive to germination cues such as smoke water and heat. The requirement for a period of burial before seeds become responsive to smoke and/or heat would ensure that seeds persist in the soil until a subsequent fire, when there is an increase in nutrients available for growth and reduced competition from other plants.

Binding and internalization of the melanocyte stimulating hormone receptor ligand [Nle(4), D-Phe(7)]alpha-MSH in B16 melanoma cells

The current study aims to ascertain the fate of the melanocyte stimulating hormone (MSH) receptor and its ligand [Nle(4), D-Phe(7)]alpha-MsH (NDP-MSH) following binding to murine B16 melanoma cells. Cells were incubated with [I-125]-NDP-MSH for up to 180 min and binding, internalization and degradation determined. Intracellular trafficking of the radiolabel was assessed !using Percoll density gradient centrifugation of homogenized cells. Receptor down-regulation and receptor mRNA levels were also measured over 96 hr after exposure to 1 mu M ligand. NDP-MSH accumulation increased with time in a temperature-dependent manner and was inhibited by excess peptide. The ligand was rapidly internalized and translocated to the lysosomal compartment where it was degraded. Internalization was accompanied by a loss or down-regulation of cell surface receptors, suggesting internalization of the NDP-MSH-receptor complex. No recycling of the receptors between the plasma membrane and intracellular compartments could be detected in this cell-hue. Approximately 15% of the surface receptors were resistant to down-regulation, possibly indicating receptor heterogeneity. Down-regulation persisted ibr up to 96 hr and was accompanied by a decrease in MSH receptor mRNA levels 48 hr after treatment. However, before this time, transcript levels were the same in treated and control cells. In contrast to what was seen with NDP-MSH, cell surface receptors removed with trypsin wc:re rapidly replaced. These results show that NDP-MSH not only induced MSH receptor :internalization but also inhibited receptor turnover, resulting in a prolonged down-regulation. It is concluded that, in B16 cells, the MSH receptor undergoes ligand-dependent internalization, resulting in a prolonged down-regulation. Copyright (C) 1996 Elsevier Science Ltd

rTMS treatment for depression in Parkinson`s disease increases BOLD responses in the left prefrontal cortex

The mechanisms underlying the effects of antidepressant treatment in patients with Parkinson`s disease (PD) are unclear. The neural changes after successful therapy investigated by neuroimaging methods can give insights into the mechanisms of action related to a specific treatment choice. To study the mechanisms of neural modulation of repetitive transcranial magnetic Stimulation (rTMS) and fluoxetine, 21 PD depressed patients were randomized into only two active treatment groups for 4 wk: active rTMS over left dorsolateral prefrontal cortex (DLPFC) (5 Hz rTMS; 120% motor threshold) with placebo pill and sham rTMS with fluoxetine 20mg/d. Event-related functional magnetic resonance imaging (fMRI) with emotional stimuli was performed before and after treatment - in two sessions (test and re-test) at each time-point. The two groups of treatment had a significant, similar mood improvement. After rTMS treatment, there were brain activity decreases in left fusiform gyrus, cerebellum and right DLPFC and brain activity increases in left DLPFC and anterior cingulate gyrus compared to baseline. In contrast, after fluoxetine treatment, there were brain activity increases in right premotor and right medial prefrontal cortex. There was a significant interaction effect between groups vs. time in the left medial prefrontal cortex, suggesting that the activity in this area changed differently in the two treatment groups. Our findings show that antidepressant effects of rTMS and fluoxetine in PD are associated with changes in different areas of the depression-related neural network.

Long-Term Results of Percutaneous Bilioenteric Anastomotic Stricture Treatment in Liver-Transplanted Children

The purpose of this study was to evaluate the mid- and long-term results of percutaneous transhepatic cholangiography (PTC) and biliary drainage in children with isolated bilioenteric anastomotic stenosis (BAS) after pediatric liver transplantation. Sixty-four children underwent PTC from March 1993 to May 2008. Nineteen cholangiograms were normal; 10 showed intrahepatic biliary stenosis and BAS, and 35 showed isolated BAS. Cadaveric grafts were used in 19 and living donor grafts in 16 patients. Four patients received a whole liver, and 31 patients received a left lobe or left lateral segment. Roux-en-Y hepaticojejunostomy was performed in all patients. Indication for PTC was based on clinical, laboratory, and histopathologic findings. In patients with isolated BAS, dilation and biliary catheter placement, with changes every 2 months, were performed. Patients were separated into 4 groups according to number of treatment sessions required. The drainage catheter was removed if cholangiogram showed no significant residual stenosis and normal biliary emptying time after a minimum of 6 months. The relationship between risk factors (recipient`s weight < 10 kg, previous exposure to Cytomegalovirus, donor-recipient sex and weight relations, autoimmune disease as indication for transplantion, previous Kasai`s surgery, use of reduced liver grafts, chronic or acute rejection occurrence) and treatment was evaluated. Before PTC, fever was observed in 46%, biliary dilation in 23%, increased bilirubin in 57%, and increased gamma-glutamyltransferase (GGT) in 100% of patients. In the group with BAS, 24 of 35 (69%) patients had histopathologic findings of cholestasis as did 9 of 19 (47%) patients in the group with normal PTC. Of the 35 patients, 23 (65.7%) needed 1 (group I), 7 needed 2 (group II), 4 needed 3 (group III), and 1 needed 4 treatment sessions (group IV). The best results were observed after 1 treatment session, and the mean duration of catheter placement and replacement was 10 months. The primary patency rate was 61.2%, and the recurrence rate was 34.3% (group I). Seven patients (7 of 35; 20%) had their stricture treated with a second treatment session (group II). The average drainage time in group II was 24 months. During a period > 20 months, 4 patients (4 of 35; 11.4%) required 1 additional treatment session (group III), and 1 patient (1 of 35; 2.9%) had a catheter placed at the end of the study period (group IV). Drainage time in group I was significantly shorter than those in groups II, III, and IV (p < 0.05). There was no statistically significant relation between therapeutic response and the selected risk factors (p > 0.05). The majority of complications, such as catheter displacement and leakage, were classified as minor; however, 2 patients (5.7%) with hemobilia were noted. Complications increased according to the need for reintervention. In conclusion, balloon dilation and percutaneous drainage placement is safe and effective, and it has long-term patency for children with BAS after liver transplantation. Because of prolonged treatment time, reintervention may be necessary, thereby increasing the complication rate. Balloon dilation and percutaneous drainage placement should be considered as the first treatment option because of its minimally invasive nature.

Plasma Osteopontin Levels in Patients With Head and Neck Cancer Undergoing Chemoradiotherapy

Objectives: To explore the prognostic role of plasma levels of osteopontin (OPN), a phosphoglycoprotein with adhesive properties, in patients with head and neck squamous cell carcinoma (HNSCC) undergoing concomitant chemoradiotherapy. Previous studies have proposed OPN level as a prognostic factor in several cancers. Design: Prospective analysis of plasma OPN levels, before and within 12 weeks after treatment, in a cohort of patients with HNSCC undergoing platinum-based chemoradiotherapy at our center. Setting: Academic center. Patients: Sixty-nine patients diagnosed as having HNSCC. Interventions: Plasma levels of OPN were assessed before the start and after the conclusion of chemoradiotherapy by using an enzyme-linked immunosorbency assay kit. Chemoradiotherapy was exclusive (n = 52) or adjuvant to surgery (n = 17). Main Outcome Measures: Levels of OPN were correlated with clinicopathological characteristics, to treatment, and overall survival. Results: Pretreatment plasma OPN levels were higher in patients with advanced T and N stages compared with patients with early stages (P = .009 and .07, respectively). Mean (SD) plasma levels of OPN measured before (102.5 [68.1] ng/mL) and after (104.0 [53.6] ng/mL) treatment did not differ (P = .18, paired t test). Pretreatment and posttreatment levels of OPN were lower in patients who achieved a complete response compared with those who failed to respond (75.0 [41.5] vs 131.2 [82.9] ng/mL [P = .005] and 86.8 [40.5] vs 141.6 [58.4] ng/mL [P = .004], respectively). Patients with high pretreatment OPN levels (> 82.1 ng/mL) had shorter survival time (P < .001). Posttreatment OPN levels were marginally (P = .10) associated with survival time in univariate analysis. Conclusions: In patients with HNSCC undergoing chemoradiotherapy, a low pretreatment plasma OPN level is associated with treatment response and better survival. Modulation of OPN levels by chemoradiotherapy may also be associated with outcome. Further studies with serial measurement of OPN levels are warranted in these patients.

Contractions of specific abdominal muscles in postural tasks are affected by respiratory maneuvers

The influence of respiratory activity of the abdominal muscles on their reaction time in a postural task was evaluated. The electromyographic (EMG) onsets of the abdominal muscles and deltoid were evaluated in response to shoulder flexion initiated by a visual stimulus occurring at random throughout the respiratory cycle. Increased activity of the abdominal muscles was produced by inspiratory loading, forced expiration below functional residual capacity, and a static glottis-closed expulsive maneuver. During quiet breathing, the latency between activation of the abdominal muscles and deltoid was not influenced by the respiratory cycle. When respiratory activity of the abdominal muscles increased, the EMG onset of transversus abdominis and internal oblique, relative to deltoid, was significantly earlier for movements beginning in expiration, compared with inspiration [by 97-107 ms (P < 0.01) and 64-90 ms (P < 0.01), respectively]. However, the onset of transversus abdominis EMG was delayed by 31-54 ms (P < 0.01) when movement was performed during a static expulsive effort, compared with quiet respiration. Thus changes occur in early anticipatory contraction of transversus abdominis during respiratory tasks but they cannot be explained simply by existing activation of the motoneuron pool.

Oral sensorimotor function for feeding in patients with tetanus

Tetanus still remains a significant health problem in developing countries; it is a serious disease with a high mortality rate. The purpose of this study was to characterize the oral sensorimotor function for feeding in patients with tetanus. Thirteen patients clinically diagnosed with tetanus and admitted to an intensive care unit between December of 2005 and May of 2007 underwent a screening too) for dysphagia, involving the assessment of clinical features and 2 swallowing tests. Results indicate that the oral sensorimotor function for feeding in these patients is severely compromised, with the exception for the clinical feature of palate elevation and performance in the saliva swallowing test. The factor analysis indicated that the evaluation of tongue movement change in the oromotor examination is important in predicting alterations of cough/voice in the water swallowing test, thus suggesting that oral feeding might be unsafe. When looking at developing countries, the prolonged intensive medical and nursing care required by many patients with tetanus places extra demands on an already stretched healthcare budget. Intervention by a speech pathologist could mean that time in the ICU would be reduced as well as the number of re-admissions due to complications. (C) 2009 Elsevier B.V. All rights reserved.

Tube feeding with a diabetes-specific feed for 12 weeks improves glycaemic control in type 2 diabetes patients

Background and aims: Assess longer-term (12 weeks) effects of a diabetes-specific feed on postprandial glucose response, glycaemic control (HbA1c), lipid profile, (pre)-albumin, clinical course and tolerance in diabetic patients. Methods: In this randomized, controlled, double-blind, parallel group study 25 type 2 diabetic patients on tube feeding were included. Patients received a soy-protein based, multi-fibre diabetes-specific feed or isocaloric, fibre-containing standard feed for 12 weeks, while continuing on their anti-diabetic medication. At the beginning, after 6 and 12 weeks, several (glycaemic) parameters were assessed. Results: The postprandial glucose response (iAUC) to the diabetes-specific feed was lower at the 1st assessment compared with the standard feed (p = 0.008) and this difference did not change over time. HbA1c decreased over time in the diabetes-specific and not in the standard feed group (treatment*time:p = 0.034): 6.9 +/- 0.3% (mean +/- SEM) at baseline vs. 6.2 +/- 0.4% at 12 weeks in the diabetes-specific group compared to 7.9 +/- 0.3% to 8.7 +/- 0.4% in the standard feed group. No significant treatment*time effect was found for fasting glucose, insulin, (pre-) albumin or lipid profile, except for increase of HDL in the diabetes-specific group. Conclusions: The diabetes-specific feed studied significantly improved longer-term glycaemic control in diabetic patients. This was achieved in addition to on-going anti-diabetic medication and may affect clinical outcome. (C) 2009 Elsevier Ltd and European Society for Clinical Nutrition and Metabolism.