Dependence of radiochromic film response kinetics on fractionated doses

Because the rate and magnitude of the post-exposure growth of the MD-55 radiochromic film (RCF) dosimeter response depends significantly on total dose, we have investigated the influence of fractionation and protracted dose delivery on optical density (OD) as a function of total dose and the exposure-to-densitometry time interval for a 633-nm scanning laser densitometer. Both measurements and models demonstrate that fractionation induces transient OD over responses, which can be as large as 20%, but rapidly dissipate within 24 h. However, the superposition model predicts 2-5% over responses that persist as long as 700 h.

A Coarse Grained Model for DNA and Polymer Packaging: Statics and Dynamics

We present a numerical characterization of the statics and dynamics of the packaging of a semi-flexible polymer inside a sphere. The study is motivated by recent experiments on the packaging of DNA inside viral capsids. It is found that the force required to confine the coarse-grained polymer is in fair agreement with that found in experiments for the packaging of the phi29 bacteriophage genome. Despite its schematic nature, the model is capable of reproducing the most salient dynamical features of packaging experiments such as the presence of pauses during individual packaging processes and the trend of the resisting force as a function of chain packed fraction.

Enantiomeric separation of glutethimide derivatives using a Ceramospher RU-2 column

The enantiomeric resolution of p-acetylaminoglutethimide and p-nitroglutethimide was achieved on a Ceramospher RU-2 column using methanol as the mobile phase. The flow rates of the mobile phase were 1.0 and 0.5 mL/min for p-acetylaminoglutethimide and p-nitroglutethimide, respectively, with UV detection at 254 nm. The values of alpha of the resolved enantiomers of p-acetylaminoglutethimide and p-nitroglutethimide were 1.63 and 1.24 while the values of Rs were 1.44 and 0.86 respectively. The possible chiral mechanism was the formation of transient diastereomeric intermediates between the enantiomers and the chiral selector (1,10-phenanthroline) ruthenium II complex which was stabilized by pi-pi interactions.

Oxidative stress is implicated in the pathogenesis of lichen sclerosus

BACKGROUND

Lichen sclerosus (LS) is a chronic inflammatory skin disease of unknown aetiology which can be associated with secondary malignancies. Recent evidence supports an autoimmune basis for this disorder, as demonstrated by autoantibodies to extracellular matrix protein 1 (ECM-1). The pathophysiological mechanisms leading to autoimmunity and carcinogenesis are poorly understood.

OBJECTIVES

We hypothesized that oxidative stress, which has been demonstrated to be involved in the pathogenesis of several autoimmune and malignant disorders, contributes to these processes in LS.

METHODS

Skin biopsies from 16 patients with untreated, histologically confirmed vulval LS were examined immunohistochemically using antibodies against the lipid peroxidation products malondialdehyde and 4-hydroxynonenale and against the oxidative DNA damage marker 8-hydroxy-2'-deoxyguanosine. Protein carbonyls as markers of protein oxidation were visualized using the dinitrophenylhydrazone method. Expression of antioxidant enzymes was investigated. Normal vulval tissue from 16 subjects served as control.

RESULTS

In vulval LS tissue a significant increase of lipid peroxidation products was found particularly within the basal cell layers of the epidermis, thus colocalizing with ECM-1. Oxidative DNA damage was detected throughout LS biopsies. Intriguingly, protein oxidation was significantly increased within the dermis of LS lesions, indicating oxidative protein damage in the areas of sclerosis and inflammation. The enzymatic antioxidant defence in LS was found to be significantly disturbed.

CONCLUSIONS

This is the first study to demonstrate oxidative damage to lipids, DNA and proteins in LS, revealing a novel pathophysiological mechanism which may contribute to sclerosis, autoimmunity and carcinogenesis. Therapeutic strategies using antioxidants might be a useful new approach in the treatment of LS and could also help to prevent secondary malignancies.

Removal of chlorophenols from wastewater using red mud: an aluminum industry waste

Removal of toxic substances from wastewaters using low-cost alternatives to activated carbon is an important area in environmental sciences. Efforts have been made to convert red mud, an aluminum industry waste, into a low-cost potential adsorbent, and the final material has been used for the removal of phenol, 2-chlorophenol, 4-chlorophenol, and 2,4-dichlorophenol from wastewater. It is pertinent to mention that phenol and chlorophenols are highly carcinogenic and an priority class of pollutants which needs to be removed from effluents before discharge into water bodies. 2,4-Dichlorophenol and 4-chlorophenol are sorbed by the developed adsorbent up to 94-97%, while the removal of 2-chlorophenol and phenol was up to 50-81%. The removal of phenols and its derivatives was achieved up to 98% by column experiments at a flow rate of 0.5 mL/min. The order of removal was 2,4-dichlorophenol > 4-chlorophenol > 2-chlorophenol > phenol, and the removal takes place through a particle diffusion mechanism. The adsorption was found to be endothermic in nature and follows both Langmuir and Freundlich models. Estimation of the phenols was carried out by capillary electrophoresis, and the adsorbent has been successfully tried for the removal of chlorophenols from a wastewater. The developed process is very useful, economic, rapid, and reproducible for the removal of phenols.

Comparison of the OptiMAL rapid antigen test with field microscopy for the detection of Plasmodium vivax and P. falciparum: considerations for the application of the rapid test in Afghanistan

To establish the sensitivity and specificity of a batch of 'OptiMAL 48' rapid antigen tests procured by the World Health Organization in Afghanistan, a sample was tested, in parallel with routine, microscopical diagnosis, at basic health units (BHU) within Afghan refugee camps in Pakistan. The results of both methods of field diagnosis were compared with those of cross-checking microscopy at a reference laboratory, which were taken as the 'gold standard'. Out of 499 patients examined, 36% were diagnosed as malaria cases by field microscopy and 34% by the rapid test. For the OptiMAL 48 test, cross-checking of the corresponding smears at the reference laboratory gave a sensitivity of 79.3% and a specificity of 99.7% for Plasmodium falciparum and corresponding values of 86.1% and 98.7% for P. vivax infections. The performance of the field microscopy was better, with a sensitivity and specificity of 85.2% and 99.7% for P. falciparum, and 90.4% and 98.7% for P. vivax, respectively. These results show that the performance of OptiMAL 48 is adequate for acute- and post-emergency situations when the alternative is just clinical diagnosis. However, in the developing health system of Afghanistan, the main focus should be on the expansion of the existing network for microscopical diagnosis and quality control, to meet the needs of a stable situation. Rapid antigen tests are more suited to investigations of outbreaks in remote situations, where health services are deficient or absent.

Thermodynamic properties of He-H2 fluid mixtures over a wide range of temperatures and pressures

The effect of pressure P and temperature T on the properties of mixing of helium-hydrogen (He-H2 ) fluid mixture is studied based on statistical mechanical perturbation theory. The constituent species are considered to be interacting via a pair potential consisting of short range repulsion and a long range attraction which has been included through a double Yukawa (DY) potential. He and H2 are the lightest elements; therefore, the quantum effect is included via first-order quantum correction in the framework of Wigner-Kirkwood expansion. The dimerization of the H2 molecule is treated as a hard convex body fluid for which the equation of state (EOS) can be derived from hard sphere system based on scaled particle theory. An advanced and most recent EOS has been used for our investigation. The use of the DY potential, which can readily be simulated to empirical potentials, has enabled us to obtain analytical expressions for attractive and quantum energy contributions in terms of Laplace transforms. With a view to ensure internal consistency of the various thermodynamic functions to extract information on segregation and order in the mixture, different functions, such as compressibility factor, Gibbs free energy of mixing, entropy of mixing, and concentration fluctuations in the long wavelength limit, have been calculated as functions of composition of the mixture over an extended region of P and T. The results suggest that segregation, heterocoordination, or both may occur in the He-H2 mixture depending upon its composition, pressure, and temperature.

Mucous membrane pemphigoid: nasal and laryngeal manifestations

Mucous membrane pemphigoid (MMP) is a sub-epithelial blistering disease that primarily involves mucosal surfaces but may also involve the skin. Clinically, it appears as vesiculobullous lesions of the oral cavity and eyes, but other tissues such as the nasopharyngeal and laryngeal mucosa can also be affected. Ultimately, scarring and airway stenosis may occur. The condition should be managed by a multidisciplinary team led by a dermatologist. Immunosuppressive therapy forms the mainstay of treatment, with surgery having both a diagnostic role and a use in the treatment of complications such as airway obstruction. There must be a low threshold of suspicion for laryngeal involvement in this group of patients, so that prompt action can be taken. Once laryngeal stenosis has occurred repeated endoscopic laser excision of scar tissue can be used to maintain an adequate airway. Adjuvant use of mitomycin-C can be used beneficially in the treatment of laryngeal complications of MMP.

Equilibrium uptake and sorption dynamics for the removal of a basic dye (basic red) using low-cost adsorbents

Waste carbon slurries (generated in fertilizer plants) and blast furnace slag (generated in steel plants) have been converted into low-cost potential adsorbents. The adsorbents have been characterized and tried for the removal of the dye basic red from wastewater. Studies were performed at different pH to find the pH at which maximum adsorption occurs. Equilibrium isotherms were determined to assess the maximum adsorption capacity of the adsorbents. Adsorption capacities are compared for activated carbon developed from fertilizer waste and activated slag developed from blast furnace waste. The adsorption data are correlated with Freundlich and Langmuir isotherms in each system. The kinetics of adsorption depends on the adsorbate concentration and the physical and chemical characteristics of the adsorbent. Studies were conducted to delineate the effect of pH, temperature, initial absorbate concentration, particle size of the adsorbent, and solid-to-liquid ratio. The adsorption of basic red was found to be endothermic and first-order in nature.

Dependence of radiochromic film optical density post-exposure kinetics on dose and dose fractionation

Radiochromic film (RCF) has been shown to be a precise and accurate secondary planar dosimeter for acute exposure radiation fields. However, its application to low dose-rate brachytherapy has been questioned because of possible dose-rate effects. To address this concern, we have measured the optical density (OD) of Model 55-2 RCF as a function of time (interval between the completion of irradiation and densitometry using a 633 nm laser scanner) following exposure (from less than 1 hour to 90 days) for single and split doses from 1 Gy to 100 Gy. Our work demonstrates that film darkening as a function of post-irradiation time depends significantly on total dose, with films exposed to lower doses developing faster than films given higher doses. At 1 Gy, the OD 90 days after exposure is 200% larger than that measured 1 h after exposure compared to a 20% increase over 90 days for doses larger than 20 Gy. An empirical model with time-independent, fast and slow growth terms was used to fit single exposure data. The dependence of the resulting best-fit parameters on dose was investigated. Splitting the dose into two fractions (20 Gy followed by doses of 1-80 Gy 24 h later) results in modest post-irradiation time-dependent changes in the total optical density (at most 15% at small doses), which dissipates within 20 hours following the second exposure. This experimental finding is consistent with the predictions of a simple cumulative dose superposition model. Overall, both experimental and empirical modeling suggest that dose-rate effects may be relatively small despite the strong dependence of film darkening kinetics on total dose. However, more experimental evaluation of radiochromic film response dependence on dose rate and dose-time-fractionation patterns is needed.

Thermodynamic study of the enantiomeric resolution of flurbiprofen by HPLC using Chiralpak AD-RH column

The chiral resolution of (+/-)-flurbiprofen was achieved using water-acetonitrile (60:40, v/v) containing 0.1% acetic acid on a Chiralpak AD-RH column at 20 degrees C. The enantio-resolution was studied with different percentages of acetonitrile. Thermodynamic parameters (enthalpy, entropy and free energy) were calculated by carrying out the enantio-resolution experiments at 0 to 60 degrees C. The enantio-resolution was found to be exothermic in nature. Attempts have been made to explain the mechanism of chiral resolution of flurbiprofen on the Chiralpak AD-RH column.

Bupropion (Zyban) toxicity

Bupropion is a monocyclic antidepressant structurally related to amphetamine. Zyban, a sustained-release formulation of bupropion hydrochloride, was recently released in Ireland, as a smoking cessation aid. In the initial 6 months since it's introduction, 12 overdose cases have been reported to The National Poisons Information Centre. 8 patients developed symptoms of toxicity. Common features included tachycardia, drowsiness, hallucinations and convulsions. Two patients developed severe cardiac arrhythmias, including one patient who was resuscitated following a cardiac arrest. All patients recovered without sequelae. We report a case of a 31 year old female who required admission to the Intensive Care Unit for ventilation and full supportive therapy, following ingestion of 13.5g bupropion. Recurrent seizures were treated with diazepam and broad complex tachycardia was successfully treated with adenosine. Zyban caused significant neurological and cardiovascular toxicity in overdose. The potential toxic effects should be considered when prescribing it as a smoking cessation aid.

Pharmacological comparison of human homomeric 5-HT3A receptors versus heteromeric 5-HT3A/3B receptors

The present study determined the detailed pharmacological profile of heterologously expressed human (h) homomeric 5-HT3A receptors in direct comparison to heteromeric h5-HT3A/3B receptors. The very minor differences in their respective pharmacological profiles indicates that the 5-HT3B receptor subunit alters, predominantly, the biophysical rather than the pharmacological properties of the 5-HT3 receptor.

Comparison of the chiral resolution of econazole, miconazole, and sulconazole by HPLC using normal-phase amylose CSPs

Resolution of the enantiomers of (+/-)-econazole, (+/-)-miconazole, and (+/-)-sulconazole has been achieved on different normal-phase chiral amylose columns, Chi-ralpak AD, AS, and AR. The mobile phase used was hexane-2-propanol-diethylamine, 400:99:1 (v/v). The flow rates of the mobile phase used were 0.50 and 1.00 mL min(-1). The alpha values for the resolved enantiomers of econazole, miconazole, and sulconazole on the chiral phases were in the range 1.63 to 1.04; the Rs values varied from 5.68 to 0.32.

Photoelectron diffraction mapping: molecules illuminated from within

We demonstrate the use of a multiparticle coincidence technique to image the diffraction of an electron wave whose source is placed at a specific site in a free molecule. Core-level photoelectrons are used to illuminate the molecule from within. By measuring the vector momenta of two molecular fragments and the photoelectron, a richly structured electron diffraction pattern is obtained in a body-fixed frame of the randomly oriented molecule in the gas phase. We illustrate this technique for CO, creating a photoelectron from the C(1s) shell and scanning its energy from zero to 30 eV.

A comparative study of the enantiomeric resolution of several tetralone derivatives on macrocyclic antibiotic chiral stationary phases using HPLC under normal phase mode

The enantiomeric resolution of five substituted 2-(4-pyridylalkyl)-1-tetralone derivatives has been achieved on three macrocyclic glycopeptide antibiotic chiral stationary phases namely, Chirobiotic R, T, and V columns. The mobile phase used was hexane-ethanol-triethylamine (12:8:0.01, v/v/v). The flow rates were 1 mL/min for Chirobiotic T and 2 mL/min for Chirobiotic R and V respectively. The UV detection was carried out at 254 nm. The values of alpha of the resolved enantiomers of the reported tetralone derivatives were in the range of 1.32 to 2.51 on Chirobiotic R, 2.02 to 2.88 on Chirobiotic T and 1.55 to 2.54 on Chirobiotic V respectively while the values of Rs were in the range of 1.00 to 2.50 on Chirobiotic R, 1.00 to 1.95 on Chirobiotic T and 1.00 to 1.60 on Chirobiotic V respectively. The best resolution was achieved on Chirobiotic R column.

Hypoperfusion-related cerebral ischemia and cardiac left ventricular systolic dysfunction

BACKGROUND

Cardiomyopathy and low ejection fraction (EF) are associated with cardiac thrombi and cardiogenic embolism but may also be risk factors for hypoperfusion-related cerebral ischemia (HRCI). Current stroke subtype criteria do not include an HRCI category.

METHOD

To look for evidence of HRCI, we compared mean infarct volume between serial patients with EF < or =35% and high-grade (> or = 70%) carotid stenosis and serial patients with normal EF and high-grade carotid stenosis. We matched serial stroke patients with EF < or =35% with stroke patients with normal EF and compared the number and type of ischemic lesion (symptomatic or asymptomatic) and mean infarct volume on magnetic resonance imaging. We blindly compared stroke subtype in these groups using modified Trial of ORG 10172 in Acute Stroke Treatment (TOAST) criteria, including an HRCI category.

RESULTS

In patients with carotid stenosis, ipsilateral infarct volume was greater with EF < or = 35% (74.7 mL, 95% CI, 17.3-132.1 mL) than in controls (17.1 mL, 95% Cl, 9.4-24.8 mL) (P<.05). There was no difference in the mean number of HRCI-compatible infarcts on computed tomography scan between patients with low EF and controls. Symptomatic HRCI occurred in 4 of 15 patients with low EF and in 0 of 15 controls.

CONCLUSIONS

Symptomatic HRCI occurs in patients with low EF. Severe arterial stenosis may interact with left ventricular systolic dysfunction to cause cerebral hypoperfusion. Modification of the TOAST criteria to include an HRCI subtype is feasible and HRCI should be included as a stroke subtype.

Environmental exposure of the pediatric age groups in Cairo City and its suburbs to cadmium pollution

In a trial to assess the exposure of subjects in the pediatric age group to cadmium (Cd) pollution, serum Cd was estimated by atomic absorption spectrometry in 405 subjects, birth-18 years old, from Cairo City and its suburbs. Serum Cd mean concentrations were: 0.92 microg/l in 32 neonates (birth-4 weeks); 1.33 microg/l in 70 infants (4 weeks-2 years); 1.11 microg/l in 100 children in the preschool period (2-6 years); 1.34 microg/l in 103 primary school children (6-12 years); and 1.24 microg/l in 100 adolescents (12-18 years). In neonates, serum Cd was higher in babies with weights and heights that remained below the 5th percentile for age. Breast-fed infants had a serum Cd geometric mean level (1.25 microg/l) that was not in accordance to that of their mothers' milk (0.52 microg/l, P < 0.001), suggesting alternative routes of exposure. Environmental tobacco-smoke exposure was the most important determinant of Cd status in the school-aged children, the geometric mean being 1.42 microg/l in passive smokers vs. 1.2 microg/l in non-exposed children (P < 0.05). Moreover, adolescents who were active smokers had a significantly higher serum Cd level (1.7 microg/l) as compared to non-smokers (1.2 microg/l). Gender did influence the Cd status in adolescents, being higher among males, probably related to smoking, or to the difference in lifestyle of adolescents according to gender in the community. Alpha-1-microglobulinuria was accompanied by a higher serum Cd concentration in the group of adolescents only, suggesting a subclinical renal effect after several years of cumulative exposure. The residential classification, whether urban or suburban, did not influence the serum Cd status; neither did the present or past history of bronchial asthma. These findings certainly justify further evaluation of the problem of Cd pollution among Cairene individuals, knowing the long-term consequences of exposure to it. Systematic efforts for the proper disposal of Cd wastes and prevention of smoking in public places are recommended.

Nodal vessels disease as a risk factor for atrial fibrillation after coronary artery bypass graft surgery

OBJECTIVE

Atrial fibrillation (AF) is common after coronary artery bypass graft (CABG) surgery. Atrial ischaemia due to diseased atrioventricular (AV) and sinoatrial (SA) arteries has been proposed as a cause of AF post-CABG. We examined if the presence of diseased nodal arteries was a significant predictor of the development of AF post-CABG.

METHODS

100 consecutive cases (AF post-CABG) were compared to 100 consecutive controls (No AF post-CABG) with respect to pre-operative angiographic evidence of diseased nodal arteries. Cases and controls identified from the Society of Thoracic Surgeons database underwent detailed chart reviews to obtain data on potential risk factors. Patients were excluded if they were undergoing anything but a routine CABG procedure, were older than 65 years, or had previous AF. All angiograms were reviewed by a single radiologist blinded to outcome. The effect of grafting diseased nodal arteries on the development of AF post-CABG was also measured. A multiple logistic regression model was utilized to measure the effect of disease in each artery on the development of AF post-CABG.

RESULTS

Cases and controls were comparable regarding potential risk factors, with the exception that the AF group was older than the non-AF group. Significant AV artery disease was detected in 78 cases compared to 74 controls (adjusted odds ratio (OR) OR=1.04, CI, 0.51-2.12, P=0.82). Significant SA artery disease was detected in 34 cases compared to 21 controls (adjusted OR=2.093, CI: 1.06-4.09, P=0.03). Six of ten patients having revascularization of their SA nodal artery developed AF versus 28 of 45 of those who did not (OR=0.91, CI: 0.18-5.06, P=0.58). Forty-eight of 87 patients having revasacularization of their AV nodal artery developed AF versus 30 of 65 of those who did not (OR=1.44, CI: 0.72-2.88, P=0.27).

CONCLUSION

The presence of a diseased SA artery is significantly associated with AF post-CABG. Such association may be used to identify a subset of patients who might be targeted with prophylaxis.

Studies on the effect of alcohols on the chiral discrimination mechanisms of amylose stationary phase on the enantioseparation of nebivolol by HPLC

The chiral recognition mechanism of amylose CSPs has been described by achieving the enantiomeric resolution of (+/-)-nebivolol on Chiralpak AD and Chiralpak AD-RH columns with methanol, ethanol, 1-propanol, 2-propanol, 1-butanol as mobile phases at different flow rates. The energies of interactions of methanol, ethanol, 1-propanol, 2-propanol and 1-butanol with both phases were calculated. The (+)-RRRS enantiomer eluted first when using methanol, ethanol and 1-propanol, while the elution order was reversed when using 2-propanol and 1-butanol as the mobile phases. It has been concluded that the reversal elution order observed was due in part to the chiral cavities on the amylose CSP which were responsible for the bondings of different magnitude between chiral stationary phase and enantiomers, which are influenced with the type of alcohol used as mobile phase on the conformation of the 3,5-dimethyl phenyl carbamate moiety on the pyranose ring system of the amylose.

HPLC enantiomeric resolution of nebivolol on normal and reversed amylose based chiral phases

Racemic nebivolol, a beta-adrenergic blocker showing very promising beta-adrenergic antagonist properties in comparison to other beta-adrenergic blockers has been resolved by HPLC under normal and reversed phase modes. The columns used were Chiralpak AD and Chiralpak AD-RH containing amylose tris (3,5-dimethyl phenyl carbamate) as the chiral selector. The mobile phases used were pure ethanol and 1-propanol. The flow rates used were 0.5, 1.0 and 1.5 ml/min. The best resolution was achieved at 0.5 ml/min. flow rate with ethanol and 1-propanol on both Chiralpak AD and Chiralpak AD-RH stationary phases. The values of infinity for both alcohols on Chiralpak AD were 1.38 while on Chiralpak AD-RH these values were 1.41 and 1.38 respectively. The values of Rs for ethanol and 1-propanol were 2.63 and 1.71 on Chiralpak AD and 1.73 and 1.76 on Chiralpak AD-RH respectively.

Chrysotile asbestos fibers detected in the newborn pups following gavage feeding of pregnant mice

Female pregnant mice were fed chrysotile asbestos suspension by gavage to determine whether there is transfer of fibers to the fetuses. Groups of mice were given 2 doses of either 50 microg chrysotile suspension in 0.2 ml sterile normal saline (treated), or 0.2 ml saline (control), and were allowed to mate 2 d later. After pregnancy was confirmed, the treated and control groups received 2 additional doses of chrysotile asbestos or saline on gestational d 7 and 12. Both groups were allowed to deliver naturally, and the pups were sacrificed at 8, 1, 19, or 20 d after birth. The lungs and liver of two pups from each mother were processed for fiber counts using electron microscopy and energy-dispersive x-ray analysis (EDXA). All pups of the treated group had chrysotile fibers, while none were present in pups from controls. The mean fiber count of the lungs of treated group of pups was 780 fibers/g, and the mean fiber count of the liver was 214 fibers/g. Mean length of the fibers in the lung and liver was 18.48 microm and 18.30 microm, respectively. The fibers were thin, measuring 0.42 microm and 0.33 microm in the lung and liver, respectively. There was no significant difference in the weight gain between the treated and control group of pups. The postnatal fetal mortality of the 2 groups, 8.2% for the treated and 4.5% for the control group, were not statistically significant. To our knowledge, this is the first animal study to demonstrate that oral ingestion of chrysotile asbestos during pregnancy results in transfer of asbestos fibers to the fetuses.

Removal of DDD and DDE from wastewater using bagasse fly ash, a sugar industry waste

Bagasse fly ash, a waste from the sugar industry, was converted into an effective adsorbent and was used for the removal of DDD [2,2-Bis(4-chlorophenyl)-1,1-dichloroethane] and DDE [2,2-Bis(4-chlorophenyl)-1,1-dichloroethene] pesticides from wastewater. The DDD and DDE are removed by the developed adsorbent up to 93% at pH 7.0, with the adsorbent dose of 5 g/l of particle size 200-250 microns at 30 degrees C. The removal of these two pesticides was achieved up to 97-98% in column experiments at a flow rate of 0.5 ml/min. The adsorption was found to be exothermic in nature. The bagasse fly ash system has been used for the removal of DDD and DDE from the wastewater. The developed system is very useful, economic, and reproducible.

HPLC enantiomeric resolution of novel aromatase inhibitors on cellulose- and amylose-based chiral stationary phases under reversed phase mode

The chiral resolution of seven aromatase inhibitors (four triazole derivatives (Ia, Ib, Ic, and Id) and three tetrazole derivatives (IIa, IIb, and IIc)) was achieved on Chiralcel OJ-R [cellulose tris (4-methyl benzoate)], Chiralcel OD-RH [cellulose tris (3,5-dimethylphenyl carbamate)], and Chiralpak AD-RH [amylose tris (3,5-dimethylphenyl carbamate)] chiral stationary phases. The mobile phases used were A: 2-PrOH-MeCN (90:10, v/v); B: 2-PrOH-MeCN (50:50, v/v); C: MeCN-H(2)O (50:50, v/v); D: MeCN-H(2)O (80:20, v/v); and E: MeCN-H(2)O (95:05, v/v). The flow rate was 0.5 mL/min for all the mobile phases. The resolution capability of these chiral stationary phases were in the order Chiralpak AD-RH > Chiralcel OD-RH > Chiralcel OJ-R. The values of alpha and Rs of the resolved enantiomers of the aromatase inhibitors varied from 1.02-5.63 and 1. 12-6.72, respectively.

Hemolysis of human red blood cells by riboflavin-Cu(II) system

The photodynamic action of riboflavin is generally considered to involve the generation of reactive oxygen species, whose production is enhanced when Cu(II) is present in the reaction. In the present study we report that photoactivated riboflavin causes K(+) loss from fresh human red blood cells (RBC) in a time dependent manner. Addition of Cu(II) further enhances the K(+) loss and also leads to significant hemolysis. Riboflavin in a 2:1 stoichiometry with Cu(II) leads to maximum K(+) loss and up to 45% hemolysis. Bathocuproine, a specific Cu(I)-sequestering agent, when present in the reaction, inhibits the hemolysis completely. Free radical scavengers like superoxide dismutase, potassium iodide and mannitol inhibited the hemolysis up to 55% or more. However, thiourea was the most effective scavenger showing 90% inhibition. These results suggest that K(+) leakage and hemolysis of human RBC are basically free radical mediated reactions.

Impaired activation of cytosolic phospolipase A(2) in inflamed canine colonic circular muscle

BACKGROUND & AIMS

Arachidonic acid (AA) is a critical second messenger in several cell types. We examined whether cholinergic AA acts as a second messenger in contraction of colonic circular muscle cells and if this role is altered by inflammation.

METHODS

The experiments were performed on single dispersed cells. AA release was measured by high-performance liquid chromatography. Escherichia coli membranes labeled with (3)H-AA were used as a substrate for determining phospholipase A(2) (PLA(2)) activity, and Western immunoblotting for protein expression.

RESULTS

Acetylcholine and the PLA(2) activator melittin induced cell contractions and AA release. Both effects were inhibited by the PLA(2) inhibitor ONO-RS-082. Cytosolic and membrane PLA(2) activities increased in response to acetylcholine. These were blocked by ONO-RS-082 and cytosolic PLA(2) 100-kilodalton antibody, but not by dithiothreitol, a secretory PLA(2) inhibitor. Acetylcholine- and melittin-stimulated release of AA and their contractile response were attenuated in inflamed cells. Immunoblotting indicated that the protein expression of cPLA(2) was suppressed during inflammation.

CONCLUSIONS

AA acts as a second messenger in muscarinic receptor-activated contractions of colonic circular muscle cells. cPLA(2) is the primary enzyme that releases AA in these cells; its expression as well as activation are significantly attenuated by inflammation. The attenuated release of AA may partly account for the inhibition of colonic circular muscle tone and phasic contractions observed during inflammation.

Progress in cancer chemoprevention

More than 40 promising agents and agent combinations are being evaluated clinically as chemopreventive drugs for major cancer targets. A few have been in vanguard, large-scale intervention trials--for example, the studies of tamoxifen and fenretinide in breast, 13-cis-retinoic acid in head and neck, vitamin E and selenium in prostate, and calcium in colon. These and other agents are currently in phase II chemoprevention trials to establish the scope of their chemopreventive efficacy and to develop intermediate biomarkers as surrogate end points for cancer incidence in future studies. In this group are fenretinide, 2-difluoromethylornithine, and oltipraz. Nonsteroidal anti-inflammatories (NSAID) are also in this group because of their colon cancer chemopreventive effects in clinical intervention, epidemiological, and animal studies. New agents are continually considered for development as chemopreventive drugs. Preventive strategies with antiandrogens are evolving for prostate cancer. Anti-inflammatories that selectively inhibit inducible cyclooxygenase (COX)-2 are being investigated in colon as alternatives to the NSAID, which inhibit both COX-1 and COX-2 and derive their toxicity from COX-1 inhibition. Newer retinoids with reduced toxicity, increased efficacy, or both (e.g., 9-cis-retinoic acid) are being investigated. Promising chemopreventive drugs are also being developed from dietary substances (e.g., green and black tea polyphenols, soy isoflavones, curcumin, phenethyl isothiocyanate, sulforaphane, lycopene, indole-3-carbinol, perillyl alcohol). Basic and translational research necessary to progress in chemopreventive agent development includes, for example, (1) molecular and genomic biomarkers that can be used for risk assessment and as surrogate end points in clinical studies, (2) animal carcinogenesis models that mimic human disease (including transgenic and gene knockout mice), and (3) novel agent treatment regimens (e.g., local delivery to cancer targets, agent combinations, and pharmacodynamically guided dosing).

Progress in cancer chemoprevention: development of diet-derived chemopreventive agents

Because of their safety and the fact that they are not perceived as "medicine," food-derived products are highly interesting for development as chemopreventive agents that may find widespread, long-term use in populations at normal risk. Numerous diet-derived agents are included among the >40 promising agents and agent combinations that are being evaluated clinically as chemopreventive agents for major cancer targets including breast, prostate, colon and lung. Examples include green and black tea polyphenols, soy isoflavones, Bowman-Birk soy protease inhibitor, curcumin, phenethyl isothiocyanate, sulforaphane, lycopene, indole-3-carbinol, perillyl alcohol, vitamin D, vitamin E, selenium and calcium. Many food-derived agents are extracts, containing multiple compounds or classes of compounds. For developing such agents, the National Cancer Institute (NCI) has advocated codevelopment of a single or a few putative active compounds that are contained in the food-derived agent. The active compounds provide mechanistic and pharmacologic data that may be used to characterize the chemopreventive potential of the extract, and these compounds may find use as chemopreventives in higher risk subjects (patients with precancers or previous cancers). Other critical aspects to developing the food-derived products are careful analysis and definition of the extract to ensure reproducibility (e.g., growth conditions, chromatographic characteristics or composition), and basic science studies to confirm epidemiologic findings associating the food product with cancer prevention.

[Chloroquine sensitivity of Plasmodium falciparum at the Gamkalley Clinic and the Nigerian armed forces PMI (Niamey, Niger)]

In vivo tests for Plasmodium falciparum were carried out in 1998 during the rainy season among children in Niamey, in the Republic of Niger. Chloroquine was prescribed at 25 mg/kg for 3 days in febrile patients with uncomplicated P. falciparum malaria. Forty-five 1-5 year-olds and thirty-three 6-15 year-olds were included in the study. A group of 53 adult patients was also surveyed to evaluate the efficacy of chloroquine in semi-immune persons. Body temperature and blood smears including parasitemia were recorded on days 0, 3, 7 and 14. Less than 10% of the patients were delinquent. Around 75% of the patients were successfully treated in the 1-5 year-olds and 6-15 year old age groups. Relapses were observed in 20% of the 1-5 year-olds (early relapses 8.9%, late relapses 11.1%) and in 16.7% in the 1-15 year-olds (early relapses 6.4%, late relapses 10.3%). Among adults, successful treatment was obtained in 86.8% of the cases and early and late relapses were respectively observed in 3.8% and 1.9% of the cases. All the patients with malaria relapses were cured with second-line treatments (pyrimethamine-sulfadoxine or quinine). According to these results, chloroquine resistance appears to be moderate in Niamey. Therefore chloroquine should remain the first line treatment of uncomplicated P. falciparum malaria in this population.

The false-negative fraction: a statistical method to measure the efficacy of cervical smear screening laboratories

The false-negative fraction (FNF) is emerging as a statistical parameter that may be used to evaluate the efficacy of Papanicolaou smear screening laboratories. Our objectives for this paper are to acquaint non-laboratorians with this important measurement and to measure the FNF of the Air Force Cyto-center (AFCC) at the Armed Forces Institute of Pathology in Washington, DC. The FNF is defined as estimated false negatives divided by (true positives plus estimated false negatives). Most often, the number generated is multiplied by 100 and expressed as a percent. We have determined the FNF of the AFCC to be 3.7%. This value compares favorably with most others reported in the medical literature.

Biologic characteristics of patients with hypocellular myelodysplastic syndromes

Rates of proliferation and apoptosis as well as expression of tumor necrosis factor alpha (TNF-alpha), transforming growth factor beta (TGF-beta) and the number of macrophages were measured in bone marrow (BM) biopsies of 33 patients who presented with hypocellular (cellularity < 30%) myelodysplastic syndromes (MDS). Results showed that 2/3 of the patients had high apoptosis, high cytokine levels and large number of macrophages in their biopsies while 1/3 did not. Apoptosis and TNF-alpha levels were directly related (r = 0.583, P = 0.003, n = 24) as was apoptosis and the degree of anemia (P = 0.033, n = 18). A subgroup of patients with abnormalities of chromosomes 5 or 7 had higher platelets (P = 0.026) and higher apoptosis (P = 0.038) when compared with the rest of the group. Eight patients had no evidence of apoptosis and almost no detectable TNF-alpha in their biopsies. We conclude that within the hypocellular variant of MDS, there may be two distinct sub-groups of patients, one who present with high cytokine-mediated intramedullary apoptosis and the other who may be better characterized as having a stem-cell failure defect since they showed no evidence of apoptosis.

Biologic characteristics of 164 patients with myelodysplastic syndromes

Rates of proliferation, apoptosis and cytokine expression were measured in bone marrow (BM) biopsies of 164 myelodysplastic syndrome (MDS) patients. There were 107 males and 57 females. Median age was 69 years and 101 had refractory anemia (RA), 17 RA with ringed sideroblasts (RARS), 38 with RA and excess blasts (RAEB) and 8 with RAEB in transformation (RAEB-t). Apoptosis measured by in-situ end labeling (ISEL) was directly related to the number of macrophages (p = 0.028, n = 83). Mean tumor necrosis factor alpha (TNF-alpha) and ISEL positivity were higher in RAEB + RAEB-t patients (p = 0.0554 and p = 0.06 respectively) while hemoglobin was higher for RA + RARS group (p = 0.0472). Patients with high apoptosis had lower white blood cell counts (p = 0.0009), lower percentage of blasts (p = 0.0009) and higher number of macrophages (p = 0.0086). We conclude that measurements of apoptosis, proliferation and cytokine expression provide important biological information which helps to distinguish RA + RARS patients from RAEB + RAEB-t patients, and may be of additive prognostic significance.

Rate of psychiatric illness 1 year after traumatic brain injury

OBJECTIVE

Neurobehavioral symptoms are not uncommon after a traumatic brain injury. However, psychiatric syndromes per se have rarely been studied in patients with such an injury. The purpose of this study was to evaluate the type and extent of psychiatric syndromes in patients with traumatic brain injury.

METHOD

One hundred ninety-six hospitalized adults were studied 1 year after a traumatic brain injury with the use of a two-stage psychiatric diagnostic procedure. Psychiatric diagnoses were made according to ICD-10 criteria on the basis of data from the Schedules for Clinical Assessment in Neuropsychiatry interview.

RESULTS

Of 164 patients interviewed, 30 (18.3%) had an ICD-10 diagnosis of a psychiatric illness. Among the 120 patients who were 18-64 years old, 21.7% had a psychiatric illness, compared with 16.4% in a study of the general population. A depressive illness was present in 13.9% of the traumatic brain injury patients, compared with 2.1% of the general population, and panic disorder was present in 9.0%, compared with 0.8% of the general population.

CONCLUSIONS

In comparison with the general population, a higher proportion of adult patients had developed psychiatric illnesses 1 year after a traumatic brain injury; the rates of depressive episode and panic disorder were significantly higher in the study group. A history of psychiatric illness, an unfavorable global outcome according to the Glasgow Outcome Scale, a lower score on the Mini-Mental State examination, and fewer years of formal education seemed to be important risk factors in the development of a psychiatric illness. Compensation claims, however, were not associated with the rate of psychiatric illness.

Biological characteristics of myelodysplastic syndrome patients who demonstrated high versus no intramedullary apoptosis

Spontaneous intramedullary apoptosis was measured in bone marrow (BM) biopsies of 175 patients with myelodysplastic syndromes (MDS) using in situ end-labeling (ISEL) of fragmented DNA. Two groups of high (n=71) versus low (n =43) levels of apoptosis were identified while 61 patients were ISEL-negative. Semiquantitative assessment of 3 cytokines, the number of macrophages and in vivo labeling indices (LI) were also determined from consecutive sections of the biopsy. Patients with high apoptosis levels tended to have a high LI (p=0.013), more macrophages in their BM biopsies (p=0.006) and higher tumor necrosis factor alpha (TNF-alpha) levels (not significant) compared to patients with no apoptosis. In addition, low risk MDS patients had significantly lower rates of apoptosis (p = 0.047) and lower levels of TNF-alpha (p = 0.055) compared to high-risk MDS patients. We conclude that the genesis of cytopenias in MDS is of multifactorial origin and that cytokine-associated apoptosis clearly identifies a distinct biological subgroup of patients who may benefit selectively by use of anti-cytokine therapies.

Evidence for the participation of arachidonic acid metabolites in trehalose efflux from the hormone activated fat body of the cockroach (Periplaneta americana)

The hypertrehalosemic hormones, HTH-I and HTH-II, activate trehalose synthesis and increase the rate of sugar efflux from Periplaneta americana fat body in vitro. These processes are unaffected by the diacylglycerol, 1-oleyl-2-acetyl-sn-glycerol, an activator of protein kinase C. Similarly, H-7 and spingosine, inhibitors of protein kinase C, are also inactive against trehalose efflux. The possibility that diacylglycerol lipase might generate an active fatty acid species was ruled out because of the failure of the inhibitor RHC-80267 to inhibit trehalose efflux. Activation of trehalose efflux from the intact fat body by HTH-I was strongly inhibited in a concentration dependent manner by the cyclooxygenase inhibitors indomethacin and diclofenac, but not by acetylsalicylic acid. Nordihydroguaiaretic acid, a lipoxygenase inhibitor, also blocked HTH-I activated trehalose efflux in a concentration dependent fashion. The phospholipase A(2) inhibitors mepacrine and 4'-bromophenacyl bromide were also effective in decreasing the efflux of trehalose from HTH-I challenged fat body. The data suggest possible roles for arachidonic acid metabolites in the regulation of trehalose synthesis and in the efflux of the sugar from the fat body.

Light versus heavy sedation after cardiac surgery: myocardial ischemia and the stress response. Maritime Heart Centre and Dalhousie University

The influence of light versus heavy sedation after coronary artery bypass graft (CABG) surgery on the development of postoperative myocardial ischemia has not been described. After uncomplicated CABG surgery, 50 patients were randomly assigned to receive LOW (n = 24; target Ramsay Sedation Score [RSS] = 2) or HIGH (n = 26; target RSS = 4) sedation with propofol. Analgesia was provided to maintain a visual analog scale (VAS) pain score <7. Myocardial ischemia was identified perioperatively using continuous 3-lead Holter monitoring. By measuring creatine kinase (CK) MB levels preoperatively, at entry to the intensive care unit (ICU), and every 12 h for 48 h; and by obtaining serial 12-lead electrocardiograms (ECG) (preoperatively; 2, 4, 12, 24, and 48 h after ICU admission, 8:00 AM the morning after surgery; and 5 min pre- and postextubation), myocardial infarction was identified. Endocrine stress response was assessed by measuring serum cortisol levels preoperatively, on admission to the ICU, and 24 h postoperatively. In a subset of patients (LOW n = 10, HIGH n = 11), plasma and urinary catecholamine levels were also measured. There were no between-group differences in demographics, operative course, hemodynamic variables, or cortisol levels while in the ICU. The VAS pain score and target RSS were achieved and sustained, and they differed between groups. There were three myocardial infarctions in each group by CKMB criteria alone. No ECG-identifiable myocardial infarction occurred. The ST segment versus time curve (LOW 187 +/- 295 versus HIGH 1071 +/- 2137 mm/min) differed between groups. Urinary and plasma catecholamine levels were similar between groups over the observation period. We conclude that the use of a reduced sedation regimen in combination with adequate analgesia did not result in an increased endocrine stress response or risk of myocardial ischemia.

IMPLICATIONS

This randomized study of patients after coronary artery bypass surgery examined whether light (versus heavy) sedation with propofol in the intensive care unit was associated with an increased degree of myocardial ischemia. Using techniques to detect myocardial ischemia, including Holter monitoring, electrocardiogram, and myocardial enzyme measurements, no differences were found. We conclude that light sedation does not increase the endocrine stress response or the risk of myocardial infarction.

Midterm results with the Sorin Monostrut heart valve prosthesis

OBJECTIVE

To monitor the hematological and clinical sequelae of a single tilting disc cardiac valve prosthesis.

DESIGN

Prospective nonrandomized trial.

SETTING

University teaching hospital.

PARTICIPANTS

All patients receiving a single mechanical cardiac valve prosthesis were offered the Sorin Monostrut valve if they met the criteria for valve use. Seventy-five per cent of the patients entered were in New York Heart Association (NYHA) functional class III or IV. One hundred and forty-seven patients were subsequently followed at three months and then yearly after valve implantation for seven years.

MAIN OUTCOME MEASURES

At one year, preoperative indexes of hemolysis were compared with three-month and one-year postoperative values. Actuarial curves for survival, freedom from cerebrovascular events and explantation were constructed for the seven-year follow-up period.

RESULTS

Hemolysis, as measured by lactate dehydrogenase values, commonly occurs preoperatively, remaining significantly elevated three months and one year following valve implantation. Serum haptoglobin was normal preoperatively but was significantly low at one year. Anemia was uncommon and most patients had normal reticulocyte counts at one year. At three years, 81% of patients were in NYHA functional class I.

CONCLUSIONS

Midterm results show that this valve is structurally reliable and meets all current requirements for a safe mechanical valve.

Fatty acids stimulate trehalose synthesis in trophocytes of the cockroach (Periplaneta americana) fat body

Trophocytes from the disaggregated fat body of the cockroach (Periplaneta americana) respond to synthetic hypertrehalosemic hormone (HTH) by increasing the rate of trehalose synthesis. The cells give a similar response when incubated with stearic, oleic, linoleic, or arachidonic acid. A maximal increase in trehalose synthesis was obtained with 1-10 microM fatty acids. Synthesis of trehalose by the trophocytes was also increased by 1 microM prostaglandin F2alpha to nearly the same extent as that evoked by HTH. Furthermore, the data show that the trophocytes are capable of converting linoleic acid into arachidonic acid. This suggests that the cells may convert arachidonic acid, formed from the linoleic acid released by the action of HTH, to a prostaglandin which serves as an integral part of the hypertrehalosemic mechanism.

Buspirone fails to affect cocaine-induced conditioned place preference in the mouse

The conditioned place preference (CPP) procedure was employed to examine the effects of the 5-hydroxytryptamine1A (5-HT1A) receptor agonist, buspirone, on cocaine reinforcement. Cocaine (5.0 mg/kg, S.C., 30 min) produced a significant place preference whereas buspirone (0.5-2.0 mg/kg, I.P., 30 min) per se failed to induce a CPP. Buspirone pretreatment (0.5-2.0 mg/kg, I.P.) 30 min prior to cocaine (5.0 mg/kg, S.C., 30 min) conditioning had no effect on the acquisition of cocaine-induced CPP. Pretreatment with buspirone on the postconditioning test day also failed to affect the expression of an already established place preference response to cocaine. These results demonstrate an inability of buspirone to block both the acquisition and the expression of cocaine reward, as modeled in the CPP paradigm.

Evidence that free fatty acids in trophocytes of Periplaneta americana fat body may be regulated by the activity of phospholipase A2 and cyclooxygenase

Previous studies have shown that palmitic, stearic, oleic and linoleic acid levels in trophocytes prepared from the fat body of male Periplaneta americana are increased following treatment of the cells with hypertrehalosemic hormone (HTH). Melittin, an activator of phospholipase A2, mimicked the action of HTH by increasing the free fatty acid content in a concentration-dependent manner. The increase caused by HTH could be eliminated by pretreatment of the trophocytes with 1 mM 4'-bromophenacyl bromide (BPB), an inhibitor of phospholipase A2. BPB also decreases the concentration of free fatty acids in trophocytes not treated with HTH but by a smaller margin. Nordihydroguaiaretic acid (NDGA) and indomethacin, inhibitors of lipoxygenase and cyclooxygenase, respectively, eliminated the increase in free fatty acids evoked by HTH. In the absence of HTH both inhibitors increased the free fatty acid content of the trophocytes, an effect consistent with the known mode of action of these agents. None of the inhibitors tested, all of which blocked HTH activated trehalose synthesis, prevented activation of phosphorylase by HTH. This is taken as evidence that other downstream sites are also important in the regulation of trehalose production by the fat body. It is suggested that the increase in free fatty acids evoked by HTH, or metabolites of those fatty acids, may regulate the synthesis and release of trehalose from the trophocytes because of potential effects on trehalose phosphate synthase, trehalose 6-phosphate phosphatase, and the trehalose transport mechanism in the trophocyte membrane.

Prognostic significance of multiple genetic lesions on chromosomes 19, 10, and 17 in oligodendrogliomas

Patients diagnosed with oligodendrogliomas/oligoastrocytomas and with somatic loss of genes on chromosome 19q13.2-q13.3 survived for >5-6 years, a survival period typical of the tumors of oligodendroglial origin. One patient with oligoastrocytoma, harboring allelic loss on chromosome 10p in the tumor DNA, had a recurrence five years later with progression to anaplastic astrocytoma. However, another patient with oligoastrocytoma, whose tumor suffered multiple genetic lesions on chromosomes 19q13.2-13.3, 10q22-24, and 17p13.1 (a point mutation in the p53 gene), had two subsequent recurrences as anaplastic astrocytomas and a survival period of 29 months. Our data suggest that in tumors of oligodendroglial origin the inactivation of a tumor suppressor gene on chromosome 10, especially in conjunction with other genetic aberrations, is indicative of aggressive clinical course.