Preparing for the renaissance: treating breast cancer during the COVID-19 pandemic and planning for a safe re-emergence to routine surgical care within a universal health care system

The evolving covid-19 pandemic is placing tremendous pressure on health systems. [...]

A systematic review of outcomes after salvage abdominoperineal resection for persistent or recurrent anal squamous cell cancer

AIM

Up to 30% of patients with squamous cell cancer of the anus (SCCA) will require a salvage abdominoperineal resection (APR) for either persistent or recurrent disease. The objective of this study was to assess cancer-related outcomes in patients with (i) persistent or (ii) recurrent SCCA.

METHOD

Embase and MEDLINE were searched. Publications were included if they assessed overall survival (OS), disease-free survival (DFS) and locoregional recurrence or metastatic disease after salvage APR for persistent or recurrent SCCA.

RESULTS

A total of 28 retrospective case series (study size ranged from nine to 111) met our inclusion criteria. The median time to salvage APR was 2.6 months [interquartile range (IQR) 2.6-5.0 months, six studies] for persistent disease and 27.6 months (IQR 15.0-32.7 months, five studies) for recurrent disease. The median 5-year OS from the time of salvage APR was 45.0% (IQR 32.0%-52.3%, 10 studies) for persistent disease and 51.0% (IQR 36.0%-60.9%, 11 studies) for recurrent disease. The median 5-year DFS following salvage APR was 44.0% (IQR 29.5%-53.0%, 10 studies) for all patients. Following salvage APR, the median locoregional recurrence rate was 23.5% (IQR 15.8%- 46.9%, 19 studies) and 9.0% (IQR 6.4%-13.3%, 16 studies) of patients developed metastatic disease after salvage APR.

CONCLUSION

Our review characterizes the best evidence for outcomes following salvage APR for patients with persistent or recurrent SCCA. The evidence is limited by the quality of included studies, as many were single centre case series.

Using propidium monoazide to distinguish between viable and nonviable bacteria, MS2 and murine norovirus

AIMS

The ability to distinguish between viable and/or infectious micro-organisms and inactivated cells is extremely important for correctly performing microbial risk assessments. In this study, we evaluated whether propidium monoazide (PMA)-qPCR could distinguish between viable and nonviable bacteria and viruses.

METHODS AND RESULTS

A PMA-qPCR combined assay was applied to viable and inactivated bacteria (Escherichia coli and Bacillus subtilis) and viruses (MS2 and murine norovirus [MNV]). PMA, a DNA-intercalating agent, in combination with PCR was better able to distinguish between viable and nonviable bacteria and viruses than conventional PCR.

CONCLUSIONS

These results suggest that a combined PMA-qPCR assay can be used to measure the viability of bacterial cells and bacteriophage MS2, but not MNV.

SIGNIFICANCE AND IMPACT OF THE STUDY

PMA-qPCR could potentially be used to measure the viability of some micro-organisms, including virus. However, a thorough evaluation should be performed prior to measuring the viability of micro-organisms by PMA-qPCR in a quantitative way.

Participation in continuing professional development by dental practitioners in Victoria, Australia in 2007

BACKGROUND

Mandatory continuing professional development (CPD) was introduced in 2005 in Victoria, Australia to ensure that dental practitioners maintained their skills, knowledge and kept up-to-date with current topics in dentistry. The aim of this study was to investigate the participation, impact on practice and attitudes of Victorian dentists and dental specialists to CPD activities since the commencement of mandatory CPD.

METHODS

A cross-sectional survey of a random sample of registered dentists and dental specialists (n = 895) was conducted from May to August 2008 using an anonymous, postal, self-administered questionnaire.

RESULTS

The response rate was 66%. More than three quarters of practitioners believed mandatory CPD is a reasonable requirement for continued registration. Dentists reported attending an average of 30.9 h of certifiable clinical CPD whilst specialists attended an average of 33.2 h of certifiable clinical CPD over a 12-month period. Nearly three quarters of respondents reported changing their practice as a result of CPD activities, whilst one quarter attended CPD mainly to meet the mandatory requirements.

CONCLUSIONS

Overall there was a positive attitude towards mandatory CPD and a high level of participation in CPD activities by Victorian dentists and specialists in 2007, although nearly half of the respondents attended <20 h of certified clinical CPD during 2007. A number of barriers exist, particularly for rural and female practitioners in accessing CPD, and further research is required to examine the benefits derived from mandatory CPD.

A simple risk score to identify Southern Chinese at high risk for diabetes

AIMS

To develop a simple scoring system for identifying Southern Chinese at risk of diabetes.

METHODS

The score was derived from a risk factor matching cohort for Type 2 diabetes in Hong Kong Chinese (cohort 1, 2448 subjects without a history of diabetes; age, mean +/- sd 37.2 +/- 8.9 years, median 36.0 years; 1649 had risk factors for diabetes and 799 were age-matched control subjects from the community). Two other cohorts were used to validate the risk score (cohort 2, 3734 subjects with risk factors for diabetes; and cohort 3, 1513 participants of a community diabetes survey). All subjects had a 75 g oral glucose tolerance test (OGTT).

RESULTS

In cohort 1, 270 (11%) of the subjects were found to have diabetes on OGTT. A risk score system was derived using the beta values of the corresponding predictors in the logistic regression analysis. The area under the curve (95% confidence intervals) of the score system was 0.735 (0.705, 0.765). The application of a risk score of > or = 16 increased the detection rate 2.5-4 times in all three cohorts. A high post-test probability of diabetes of > 60% was derived from a risk score of > or = 20. Only 10-20 and approximately 5% with a score of > or = 12 and > or = 16, respectively, are indicated for OGTT. This will considerably improve the yield of OGTT screening.

CONCLUSIONS

A simple risk score identifies young-to-middle-aged Southern Chinese at high risk for diabetes. Subjects with a score of 16 or above (out of 30) should undergo OGTT for definitive diagnosis of diabetes.

The Joint Asia Diabetes Evaluation (JADE) Program: a web-based program to translate evidence to clinical practice in Type 2 diabetes

AIMS

The Joint Asia Diabetes Evaluation (JADE) Program is the first web-based program incorporating a comprehensive risk engine, care protocols, clinical decision and self-management support to improve ambulatory diabetes care. The aim was to validate the risk stratification system of the JADE Program using a large prospective cohort.

METHODS

The JADE interactive risk engine stratifies patients into different risk levels using results from an annual comprehensive assessment of complications and risk factors. We used a prospective registry consisting of 7534 Type 2 diabetic patients [45.6% men, median (range) age 57 years (13-92)] to perform internal validation of the risk engine.

RESULTS

The JADE Risk Engine categorized patients into four risk levels (from low to high): level 1, n = 4520 (6%); level 2, n = 1468 (19.5%); level 3, n = 4476 (59.4%); and level 4, n = 1138 (15.1%). After a median follow-up period of 5.5 years (mean +/- sd 5.4 +/- 2.81 years), 763 (10.1%) died, 1129 (14.9%) developed cardiovascular disease (CVD), 282 (3.7%) developed end-stage renal disease and 1400 (18.6%) had at least one of these events. Compared with risk level 1, levels 2, 3 and 4 were associated with 2.8-, 4.7- and 8.6-fold increased risk of clinical end-points. Risk levels 3 and 4 were, respectively, associated with 2.2- and 3.9-fold increased risk for all-cause death and 4.8- and 12.1-fold increased CVD risks.

CONCLUSION

Based on results from a comprehensive assessment, the JADE Risk Engine successfully categorizes patients into different risk levels to guide clinical management.

Effects of furniture polish on release of cat allergen-laden dust from wood surfaces

The purpose of this study was to evaluate the effects of furniture polish (FP) on the release of cat allergen (Fel d 1)-laden dust from wood surfaces and decay of Fel d 1 in dust over time. About 2 g of sieved (150 microm screen) allergen-laden dust was introduced as an aerosol into an experimental chamber by a Pitt-3 generator and allowed to settle onto two finished wood surfaces pre-treated with either distilled water (DW) or FP. After 24 h, each surface was vacuumed into separate plastic cassettes loaded with 37 mm diameter, 0.4 microm pore, polycarbonate filters. The recovered dust was weighed, extracted in phosphate-buffered saline, and assayed for Fel d 1 content using a two-site monoclonal antibody ELISA. After vacuuming, the remaining dust on the wood surfaces was wiped up with a water-moistened swab. The dusts were extracted from the swabs and assayed by ELISA for Fel d 1. More Fel d 1 was recovered by vacuuming from DW-pre-treated surfaces than from FP pre-treated surfaces (100% vs. 69 +/- 66%). On the contrary, more residual Fel d 1 (>99.9%) on the vacuumed surfaces was recovered from FP than from DW pre-treated surfaces by wet swabs. The concentration of Fel d 1 in dust did not change significantly at room temperature over 80 days. In conclusion, FP on wood surfaces makes dust stick to the surface, which likely reduces the release of allergen-laden dust from the wood surface.

PRACTICAL IMPLICATIONS

Re-aerosolization of cat allergen-laden dusts from wood surfaces (e.g. wood floor or furniture) significantly increases the concentration of airborne cat allergens. Our study indicates that exposure to airborne cat allergens might be reduced by surface treatment with commercially available FP because cat allergen-laden dusts stuck more tightly to the wood surface treated with FP.

Estimation of tuberculosis risk and incidence under upper room ultraviolet germicidal irradiation in a waiting room in a hypothetical scenario

Environmental control measures (ventilation, high-efficiency particulate air filtration, and upper room ultraviolet germicidal irradiation [UVGI]) are recommended to effectively control tuberculosis (TB) transmission from unsuspected TB patients in high-risk settings, but the effectiveness of their use is not often clear. This study presents a simulation model for a hypothetical hospital waiting room, in which the number of susceptible immunocompetent people in the waiting room follows a Poisson distribution (M = 5) in either low (annual number of TB patients = 5) or high TB risk settings (annual number of TB patients = 50), and used the model to evaluate the reduction of TB transmission risk by upper room UVGI. An exponential dose-response model was used for TB transmission and a two-zone model was used for evaluating the effect of upper room UVGI. Upper room UVGI reduced TB risk by 1.6-fold at 3 microW/cm2 UV irradiance in the upper room in the low TB risk setting and by 4.1-fold at 15 microW/cm2 UV irradiance in the upper room in the high TB risk setting. Use of upper room UVGI also reduced the mean annual new infection rate from 2.2 to 1.3 infections per year at 3 microW/cm2 and to 0.6 infections per year at 15 microW/cm2 in our hypothetical high-risk settings. The effect of upper room UVGI was sensitive to both vertical air velocity (air mixing) and UV irradiance level. Results from partitioning variability indicate that most variability of TB transmission risk came from waiting time in our hypothetical hospital.

Antifibrotic effect of extracellular biopolymer from submerged mycelial cultures of Cordyceps militaris on liver fibrosis induced by bile duct ligation and scission in rats

The antifibrotic effects of hot water extract (WEC), intracellular biopolymer (IPC) and extracellular biopolymers (EPC) from mycelial liquid culture of Cordyceps militaris on liver fibrosis were studied. Liver fibrosis was induced by a bile duct ligation and scission (BDL/S) operation, duration of 4 weeks in rats. In BDL/S rats, the levels of aspartate transaminase (AST), alanine transaminase (ALT), alkaline phosphatase (ALP), total bilirubin in serum and hydroxyproline content in liver were dramatically increased. The WEC or IPC treatment (30 mg/kg/day for 4 weeks, p.o.) in BDL/S rats reduced the serum AST, ALT and ALP levels significantly (p<0.01). The EPC treatment (30 mg/kg/day for 4 weeks, p.o.) reduced the serum ALT, AST and ALP levels significantly (p<0.01). Malondialdehyde contents in liver treated with WEC, IPC or EPC were significantly reduced (p<0.05). But Liver hydroxyproline content was decreased only in EPC treated BDL/S rats to 55% that of BDL/S control rats (p<0.01). The morphological characteristics and expression of alpha smooth muscle like actin in fibrotic liver, which appeared in BDL/S control group were improved in EPC treated fibrotic liver. These results indicate that EPC (30 mg/kg/day for 4 weeks, p.o.) has an antifibrotic effect on fibrotic rats induced by BDL/S.

Influence of relative humidity on particle size and UV sensitivity of Serratia marcescens and Mycobacterium bovis BCG aerosols

SETTING

A study of Serratia marcescens and BCG aerosols.

OBJECTIVE

To evaluate the effect of relative humidity (RH) on (1) the particle size and (2) sensitivity of 254nm germicidal ultraviolet (UV) irradiation.

METHODS

We built a RH controlled experimental chamber into which bacteria were aerosolized, exposed to varying amounts of UV irradiance over measured time periods, and quantitatively evaluated for viability. Aerosolized Serratia marcescens and bacille Calmette-Guérin (BCG) were subject to UV doses ranging from 57-829 microW. sec/cm(2), and sampled with a six-stage Andersen culture plate impactor at RHs ranging from 25-95%.

RESULTS

Percent survival for both organisms was inversely related to UV dose. Serratia marcescens was more susceptible to UV than BCG under all conditions. More than 95% of the bacterial aerosol particles were 1.1-4.7 microm in aerodynamic diameter, and particles sizes increased from low (25-36%) to high (85-95%) RH. The count median diameter ranged from 1.9-2.6 microm for Serratia marcescens and from 2.2-2.7 microm for BCG as RH increased. For both Serratia marcescens and BCG, resistance to UV increased as RH increased. The UV resistance of both Serratia marcescens and BCG aerosols dramatically increased at RH higher than 85%.

CONCLUSIONS

Our results indicate that differences in UV dose, kinds of microorganisms, airborne particle size and RH affect UV susceptibility.

Access to care and use of health services by low-income women

Data from the 1997 National Survey of America's Families (NSAF) are used to analyze access to care and use of health care services for low-income women. Three groups of women are examined: those with Medicaid coverage, those with private coverage, and those with no insurance. Findings show that uninsured women faced larger access barriers and utilized fewer services, particularly preventive care services, than women with either public or private coverage. Access and use did not differ greatly between Medicaid and privately covered women. The results suggest that expansions in coverage, either through Medicaid or through private options, could improve access to care for uninsured women.

Effect of tetrandrine on experimental hepatic fibrosis induced by bile duct ligation and scission in rats

Tetrandrine, an alkaloid isolated from the Chinese medicinal herb Stephania tetrandra, has been shown to elicit antifibrotic effects in various cell types. In the present study, the effect of tetrandrine on liver fibrosis was investigated by using bile duct ligation and scission in rats as a model of hepatic fibrosis. Treatment with tetrandrine in fibrotic rats reduced serum aspartate aminotransferase, alanine aminotransferase, and alkaline phosphatase levels to 72%, 52% and 51% that of controls at 10 mg/kg/day, respectively. Liver hydroxyproline contents in tetrandrine-treated rats with bile duct ligation and scission were also reduced to 65% of that of control rats with bile duct ligation and scission at 10 mg/kg/day. The morphological characteristics of fibrotic liver, which appeared in control bile duct ligation and scission group, were improved in tetrandrine-treated bile duct ligation and scission group. We also examined the effect of tetrandrine on cultured rat hepatic stellate cells, which plays an important role in the pathogenesis of hepatic fibrosis, activation to investigate whether it could act mainly by direct action on rat hepatic fibroblastic cells. In cultured rat hepatic stellate cells, tetrandrine reduced DNA synthesis to 57% of control hepatic stellate cells at 10 microg/ml without affecting cell viability. Smooth muscle-alpha-actin expression, the phenotypic marker of activated hepatic stellate cells, was also decreased. We conclude that tetrandrine has an antifibrotic effect on liver fibrosis in rats induced by bile duct ligation and scission, indicating that it might exert a direct effect on rat hepatic stellate cells.

Antifibrotic effect of Stephania tetrandra on experimental liver fibrosis induced by bile duct ligation and scission in rats

We examined the antifibrotic effect of a methanol extract from Stephania tetrandra (ST) on experimental liver fibrosis. Liver fibrosis was induced by bile duct ligation and scission (BDL/S) in rats. In BDL/S rats, activity levels of aspartate transaminase (AST), alanine transaminse (ALT), alkaline phosphatase (ALP), concentration of total bilirubin in serum, and hydroxyproline content of the liver were significantly increased. The ST treatment (either 100 mg/kg/day or 200 mg/kg/day, p.o. for 4 weeks) in BDL/S rats reduced the serum AST, ALT and ALP activity levels significantly (p< 0.01). Similarly, when compared to the control group, the concentration of hydroxyproline in the livers of the BDL/S rats treated with 100mg or 200mg ST treated rats decreased by 40% and 33% respectively, when compared to the BDL/S control group (p<0.01). The morphological characteristics of fibrotic liver that were observed in the BDL/S control group, improved in the ST treated BDL/S group. In the fibrotic liver of BDL/S rats treated with ST, a marked reduction in the numbers of alpha smooth muscle cell actin positive stellate cells was observed. These results indicate that doses of either 100 or 200 mg/kg/day of methanol extract from S. tetrandra, had an antifibrotic effect in rats with liver fibrosis induced by bile duct ligation and scission.

Protective effect of curcumin in rat liver injury induced by carbon tetrachloride

This study was carried out to investigate the protective effects of curcumin on acute or subacute carbon tetrachloride-induced liver damage in rats. Acute hepatotoxicity was induced by intraperitoneal injection of carbon tetrachloride after 4 consecutive days of curcumin treatment. Subacute hepatotoxicity was induced by oral administration of carbon tetrachloride twice a week during 4 weeks of curcumin treatment. In rats with acute liver injury, curcumin (100 and 200 mg kg(-1)) lowered the activity of serum alanine aminotransferase to 52-53% (P < 0.05) and aspartate aminotransferase to about 62% (P < 0.05) those of control rats. In rats with subacute liver injury, curcumin (100 mg kg(-1)) lowered the activity of serum alanine aminotransferase to 34% (P < 0.01) and alkaline phosphatase to 53% (P < 0.05) of control rats. The liver hydroxyproline content in the curcumin (100 mg kg(-1))-treated group was reduced to 48% of the carbon tetrachloride control group (P < 0.01). Malondialdehyde levels in curcumin (100 mg kg(-1)) treated rat liver was decreased to 67% of the control rat liver (P < 0.01) in subacute injury. It was concluded that curcumin improved both acute and subacute liver injury induced by carbon tetrachloride in rats.

A double-blind, placebo-controlled study of the safety, tolerability and pharmacokinetics of CP-101,606 in patients with a mild or moderate traumatic brain injury

CP-101,606 is a postsynaptic antagonist of the glutamate-mediated NR2B subunit of the N-methyl-D-aspartate (NMDA) receptor. When administered intravenously (i.v.) at the time of injury, CP-101,606 is neuroprotective in animal models of traumatic brain injury (TBI) and ischemia. Minimal adverse effects have been observed in normal human volunteers given i.v. doses of up to 3 mg/kg/hr for 72 hours. The objective of the present clinical trial was to assess the safety, pharmacokinetics, and tolerability of CP-101,606 infused for various times in patients who had suffered either an acute moderate or mild TBI (Glasgow Coma Score 9-14) or hemorrhagic stroke. Patients began receiving treatment within 12 hours of brain injury. A total of 53 subjects (45 with TBI and 8 with stroke) were randomized in a double-blind fashion to receive CP-101,606 or placebo (4 drug: 1 placebo). Drug/placebo was administered by i.v. infusion (0.75 mg/kg/hr) for 2 hours and then stopped (n = 25) or continued for 22 hours (n = 4) or 70 hours (n = 24) at a rate of 0.37 mg/kg/hr. Mean plasma drug concentrations were well above the predicted therapeutic concentration of 200 ng/ml within two hours of initiating treatment and were sustained as long as drug was infused. All the patients tolerated their drug/placebo treatment, and there were no clinically significant cardiovascular or hematological abnormalities in either group. A Neurobehavioral Rating Scale, used to detect personality changes and behavioral disturbances, indicated that all subjects showed an improvement from their postinjury, predosing baseline but did not significantly differ from each other with respect to type of head injury and/or treatment with drug or placebo. Modified Kurtzke Scoring also showed a similar pattern of improvement irrespective of type of head injury or drug/placebo treatment. This study suggests that CP-101,606, infused for up to 72 hours has no psychotropic effects and is well-tolerated in patients who have sustained a mild or moderate TBI or hemorrhagic stroke.

An open-label study of CP-101,606 in subjects with a severe traumatic head injury or spontaneous intracerebral hemorrhage

CP-101,606 is a postsynaptic antagonist of N-methyl-D-aspartate (NMDA) receptors bearing the NR2B subunit. When administered intravenously (i.v.), it decreases the effects of traumatic brain injury (TBI) and focal ischemia in animal models. Therapeutic plasma concentrations (200 ng/ml) in animals, have been well tolerated in healthy human volunteers. The purpose of the present dose escalation study was to assess the safety, tolerability, and pharmacokinetics of CP-101,606 in subjects who had suffered either an acute severe TBI (Glasgow Coma Scale 3-8) or spontaneous intracerebral hemorrhage. Thirty patients, 20 with a TBI and 10 with a stroke, were enrolled in the trial and began receiving an i.v. infusion of CP-101,606 for 2 hours, 24 hours, or 72 hours within 12 hours of brain injury. For the first two hours, the drug was given a rate of 0.75 mg/kg/hr and then stopped (n = 17) or continued for 22 (n = 2) or 70 hours (n = 11) at 0.37 mg/kg/hr. Plasma and cerebrospinal fluid (CSF) were collected at serial times during and after treatment. There were no consistent changes in blood pressure or pulse nor any clinically significant hematological or electrocardiogram (ECG) abnormalities attributable to CP-101,606. No adverse events or behavioral changes were considered to be related to the drug. Plasma concentrations of CP-101,606 over 200 ng/ml were rapidly achieved in the blood and CSF within two hours and were sustained there as long as the drug was infused. CSF concentrations were slightly higher than that in plasma by the end of infusion suggesting good penetration of CP-101,606 into the CSF. Outcome in the severe TBI patients, as measured by the Glasgow Outcome Score at six months, suggested that a two-hour infusion yielded a range of scores similar to contemporary patients with a severe TBI treated at our hospital while the outcomes of the patients treated with either a 24- or 72-hour infusion were better on average. Thus, these results indicate that CP-101,606 infused for up to 72 hours is well tolerated, penetrates the CSF and brain, and may improve outcome in the brain-injured patient.

Antifibrotic effects of the methanol extract of Polygonum aviculare in fibrotic rats induced by bile duct ligation and scission

The antifibrotic effect of the methanol extract from Polygonum aviculare (PA), Artemisia capillaris (AC) and an aqueous solution of biphenyl dimethyl dicarboxylate (DDB) on liver fibrosis were studied. Liver fibrosis was induced by a bile duct ligation and scission (BDL/S) operation, duration of 4 weeks in rats. In BDL/S rats, the levels of aspartate transaminase (AST), alanine transaminase (ALT), alkaline phosphatase (ALP), total bilirubin in serum and hydroxyproline content in liver were dramatically increased. The PA treatment in BDL/S rats reduced the serum AST, ALT and ALP levels significantly (p<0.01). Liver hydroxyproline content in PA treated BDL/S group was also reduced to 40% that of BDL/S control group (p<0.01). The morphological characteristics of fibrotic liver, which appeared in BDL/S control group were improved in the PA treated BDL/S group. But neither AC nor DDB treatment improved any parameters in fibrotic rats induced by BDL/S. These results indicate that PA has an antifibrotic effect on fibrotic rats induced by BDL/S.

Biotransformation of theophylline in cirrhotic rats induced by biliary obstruction

The object of this work was to study the pharmacokinetic differences and the cause of these differences in cirrhotic rats induced by biliary obstruction when aminophylline (8 mg/kg as theophylline, i.v.) was administered. The concentrations of theophylline and its major metabolite (1,3-dimethyluric acid) in plasma were determined by HPLC. In addition, formation of 1,3-dimethyluric acid from theophylline in microsomes and the changes in the activity of drug metabolizing enzymes, which are suggested to be involved in theophylline metabolism, were determined. In cirrhotic rats, the systemic clearance of theophylline was reduced to 30% of the control value while AUC (area under the plasma concentration-time curve) and (t1/2)beta were increased 1.3 fold and 3.5 fold, respectively. The formation of 1,3-dimethyluric acid was decreased to 30% of the control value in microsomes of cirrhotic rat liver. In cirrhotic rat liver, activities of aniline hydroxylase (CYP2E1 related), erythromycin-N-demethylase (CYP3A related), and methoxyresorufin-O-demethylase (CYP1A2 related), which were reported to be related with theophylline metabolism, were decreased to 67%, 53%, and 76% that of normal rat liver, respectively. From the results, it can be concluded that in cirrhotic rats induced by biliary obstruction, the total body clearance of theophylline is markedly reduced and it may be due to decreased activity of drug metabolizing enzymes in liver.

Antifibrotic effects of a polysaccharide extracted from Ganoderma lucidum, glycyrrhizin, and pentoxifylline in rats with cirrhosis induced by biliary obstruction

For the past few years, we have been investigating polysaccharides from Ganoderma lucidum as antifibrotic agents. In a previous study, we discovered that polysaccharides extracted from G. Iucidum lowered the collagen content in liver but had no effect on serum biochemical parameters in rats subjected to bile duct ligation and scission-induced fibrosis. In this study, we changed the extraction method and obtained polysaccharides extracted from G. Iucidum. The polysaccharide from G. Iucidum reduced the serum aspartate transaminase (AST), alanine transaminase (ALT), alkaline phosphatase (ALP) and total bilirubin and also reduced the collagen content in liver and improved the morphology. Pentoxifylline, which is reported to exhibit an antifibrotic effect in pigs with fibrosis induced by yellow phosphorus, did not have any antifibrotic effects in fibrosis induced by biliary obstruction. Glycyrrhizin, which is used in the treatment of hepatitis, reduced serum ALT and AST values but there was no significance. It had no effect on liver hydroxyproline content which implies that glycyrrhizin has no antifibrotic effect in the rats with fibrosis induced by bile duct ligation and scission. These data suggest that the polysaccharide from Ganoderma lucidum could be a promising antifibrotic agent. However, further study is needed to understand the inhibition mechanism of collagen deposition of polysaccharides from Ganoderma Iucidum and its clinical applicability remains to be established.

Elevated PLA2 activity in schizophrenics and other psychiatric patients

We measured serum phospholipase A2 (PLA2) activity in 39 schizophrenics, 26 psychiatric controls, and 26 normal controls using a radioenzymatic assay with phosphatidylcholine as precursor. Serum PLA2 activity was significantly higher in schizophrenics (p = 0.002) and other psychiatric (including substance abusing) patients (p = 0.032) than in normal controls. Enzyme activity did not differ between the schizophrenic patients and psychiatric controls. Fifty-one percent of the schizophrenics and 46% of psychiatric controls had PLA2 values above the highest value for normal controls. In the psychiatric control group higher than normal PLA2 activities were observed in all diagnostic categories, including major depression, bipolar disorder, posttraumatic stress disorder (PTSD), and substance abuse. In the context of others' findings of increased circulating PLA2 in infectious and inflammatory conditions, these increases must be viewed as disease nonspecific. The significance of these changes and their relationship to other acute-phase protein changes needs to be clarified in future research.

Dopamine in schizophrenia: a review and reconceptualization

OBJECTIVE

The initial hypothesis that schizophrenia is a manifestation of hyperdopaminergia has recently been faulted. However, several new findings suggest that abnormal, although not necessarily excessive, dopamine activity is an important factor in schizophrenia. The authors discuss these findings and their implications.

METHOD

All published studies regarding dopamine and schizophrenia and all studies on the role of dopamine in cognition were reviewed. Attention has focused on post-mortem studies, positron emission tomography, neuroleptic drug actions, plasma levels of the dopamine metabolite homovanillic acid (HVA), and cerebral blood flow.

RESULTS

Evidence, particularly from intracellular recording studies in animals and plasma HVA measurements, suggests that neuroleptics act by reducing dopamine activity in mesolimbic dopamine neurons. Post-mortem studies have shown high dopamine and HVA concentrations in various subcortical brain regions and greater than normal dopamine receptor densities in the brains of schizophrenic patients. On the other hand, the negative/deficit symptom complex of schizophrenia may be associated with low dopamine activity in the prefrontal cortex. Recent animal and human studies suggest that prefrontal dopamine neurons inhibit subcortical dopamine activity. The authors hypothesize that schizophrenia is characterized by abnormally low prefrontal dopamine activity (causing deficit symptoms) leading to excessive dopamine activity in mesolimbic dopamine neurons (causing positive symptoms).

CONCLUSIONS

The possible co-occurrence of high and low dopamine activity in schizophrenia has implications for the conceptualization of dopamine's role in schizophrenia. It would explain the concurrent presence of negative and positive symptoms. This hypothesis is testable and has important implications for treatment of schizophrenia and schizophrenia spectrum disorders.

Nifedipine blocks sleep induction by flurazepam in the rat

Previous studies have implicated the benzodiazepine receptor in the sleep-inducing effects of these widely used hypnotics, but the effector mechanism of this process is poorly understood. There is also in vitro evidence that benzodiazepines enhance calcium entry into synaptosomal preparations, leaving open the possibility that altered calcium flux may be involved in their actions. In order to explore this hypothesis, we administered intraventricular nifedipine, a calcium blocking agent. It was found that pretreatment with a dose of nifedipine which by itself does not affect sleep will prevent sleep induction by flurazepam in rats. Effects on anticonvulsant properties of flurazepam or anxiolytic effects of diazepam were not apparent. This suggests that changes in calcium channel function may be involved in the hypnotic action of benzodiazepines.