Comparison of three analytical techniques for determination of Th and U in environmental samples.

Alpha-particle spectrometry, gamma spectrometry and neutron activation analysis techniques for determination of Th and U in environmental samples have been compared. The analytical parameters studied include detection limit, accuracy, repeatability, reproducibility and surrogate recovery. The results show that neutron activation analysis technique has the best accuracy among the studied techniques; the other two techniques were assessed relative to it. The percentage difference between the three techniques results is about [-20, 20]. In addition, U and Th concentrations are generally overestimated by gamma spectrometry and alpha-particle spectrometry in all cases except Th concentration in the former technique, which is underestimated.

Epidemiology of urolithiasis with emphasis on ultrasound detection: a retrospective analysis of 5371 cases in Saudi Arabia.

This retrospective study was conducted to determine the prevalence of urinary calculi in the indigenous population of Saudi Arabia and compare it with expatriates of different nationalities working in Saudi Arabia with emphasis on the anatomic location of the calculi and the role of ultrasound in the detection and management. The study included 5371 patients (both sexes, mean age 36.6 years) examined by us from September 2004 to February 2008. The patients hailed from 30 countries, which included Bangladesh (42.3%), Pakistan (18.3%), Yemen (17.5%), India (6.5%), Sudan (3.4%), Saudi Arabia (2.8%), Egypt (2.3%) and Eritrea (1.7%). All patients were referred for abdominal/renal ultrasonography. Urinary calculi were detected in 1029 patients. The distribution of calculi was as follows: Renal 73.3%, pelviureteric junction 2.3%, proximal, middle and distal thirds of the ureter 13%, vesicouretic junction 9.8%, vesical 1.1% and urethral 0.5%. The prevalence of urinary calculi according to ethnic origin in descending order of frequency was Egyptians (29.5%), Pakistani (24.9%), Indian (23.3%),Yemeni (20.5%), Sudanese (17.6%), Bangladeshi (16.2%), Eritrean (15.4%) and Saudi Arabian (7.4%). Urinary calculi were found in 19.1% of the studied population. Approximately three-quarters of the calculi were located within the kidney. The nationalities with the highest prevalences were Egyptian, Pakistani and Indian.

Monitoring of ¹³7Cs fallout in Syrian environment.

This paper presents measurements of cesium 137 ((137)Cs) in the Syrian environment during the period between 2006 and 2010. More than 1,000 samples of soil, water, plants and aquatic life were collected from different locations. The measurements were realized using gamma spectroscopy, and the results showed that radioactivity concentrations were low overall. Concentrations ranged from below detection limits to several tens Bq kg(-1) (dry matter) or 9.8 mBq L(-1) (water), which were well below maximum allowable levels in food or drinking water as established according to Syrian national standards or the WHO/FAO Codex guidelines. However, high (137)Cs activity levels were observed in soil samples collected at a high elevation (Kadmous highs), where a mean concentration of 1,900 Bq kg(-1) was obtained.

Characterisation of hydrazides and hydrazine derivatives as novel aspartic protease inhibitors.

Virtual screening of an in-house virtual library of synthetic compounds using FlexX, followed by enzyme inhibition, identified hydrazide and hydrazine derivatives as novel aspartic protease inhibitors. These compounds inhibited human cathepsin D and Plasmodium falciparum plasmepsin-II with low micromolar concentrations (IC(50) = 1-2.5 microM). Modelling studies with plasmepsin-II predicted binding of ligands at the centre of the extended substrate-binding cleft, where hydrazide/hydrazine parts of the inhibitors acted as the transition state mimic by forming electrostatic interactions with catalytic aspartates.

Long-term consumption of sugar-rich diet decreases the effectiveness of somatodendritic serotonin-1A receptors.

8-Hydroxy-2-(di-n-propylamino)-tetralin (8-OH-DPAT), a 5-hydroxytryptamine (5-HT)-1A selective agonist was used to investigate a possible role of somatodendritic serotonin-1A receptors in the precipitation of hyperphagia and decreases of 5-HT metabolism associated with long-term consumption of sugar rich-diet. In the first part of study, dose-related hyperphagic effects of 8-OH-DPAT were monitored in freely feeding rats. In the second part of study, rats were fed freely on a sugar-rich diet (prepared by mixing standard rodent diet with table sugar in the ratio of 3:1 [w/w]) for 5 weeks. Hyperphagic effects of 8-OH-DPAT were monitored in sugar-rich diet and normal diet treated rats by injecting the drug at a dose of 0.25 mg/kg body weight, a dose that produced significant hyperphagia. Effects of 8-OH-DPAT on decreasing 5-HT metabolism in the hypothalamus were also investigated in the two groups. Results showed that administration of 8-OH-DPAT at a dose of 0.25 mg/kg body weight elicited hyperphagia and decreased 5-HT metabolism in normal diet treated animals but the effects in sugar-rich diet treated animals were smaller and not significant suggesting a decrease in the effectiveness of somatodendritic 5-HT-1A receptors, which provide a feedback control over the synthesis and release of 5-HT in terminal region. A possible mechanism involved in sugar-diet induced decreases of 5-HT metabolism is discussed.

Increasing antioxidant intake from fruits and vegetables: practical strategies for the Scottish population.

BACKGROUND: Increasing intakes of dietary antioxidants may help to reduce oxidative damage caused by free radicals and provide protection against the progression of a number of chronic diseases. The present study aimed to estimate the antioxidant intake from fruits and vegetables in the UK and Scottish population and to examine consumption models to identify potential strategies to optimize antioxidant intake from these foods. METHODS: This was a retrospective study of cross-sectional data on fruit and vegetable intake in relation to antioxidant intake. Antioxidant capacity of individual fruits and vegetables was determined by the ferric reducing antioxidant power assay and data on quantity and frequency of consumption of fruits and vegetables determined from National Diet and Nutrition Survey 2000-2001. RESULTS: Mean antioxidant intake in UK population from fruits and vegetables varied by region. In the Scottish sample (n = 123), mean antioxidant intake was estimated at 680 +/- 689 micromol day(-1) with 92% subjects consuming <400 g of fruits and vegetables per day. Consumption data showed that strawberries, apples, orange citrus fruits, purple broccoli and cauliflower were the top five sources of antioxidants from fruits and vegetables in the Scottish population. CONCLUSIONS: Appropriate selection of fruits and vegetables would help to achieve a higher antioxidant intake with the potential to produce significant health benefits.

Dose related effects of buspirone on serum electrolyte balance, plasma osmolality and systolic blood pressure (SBP) in rats.

Buspirone is a potent anxiolytic that decreases serotonin transmission. Changes in electrolyte balance, plasma osmolality and systolic blood pressure are often associated with stress-induced anxiety in rats as well as in human but effects of buspirone on changes in serum electrolytes balance, plasma osmolality and SBP of rats has not been reported. Present study concerns the effects of different doses of buspirone (0.25, 0.5, and 1 mg/kg) on serum electrolyte, plasma osmolality and systolic blood pressure (SBP) of rats. Anxiolysis related variable are also monitored. Results show that the administration of buspirone (0.25 mg/kg and 0.5 mg/kg) significantly increased the serum concentration of electrolytes and plasma osmolality but decreased the serum level of magnesium. These doses also reduced the systolic blood pressure (SBP). A dose of 1 mg/kg buspirone produced no effect on the concentration of serum electrolytes, and plasma osmolality. Anxiolytic effects of the drug were dose dependent but 1 mg/kg dose decreased the effect. The results are discussed in the context of serotonin receptors (5-HT1A) to be involved in buspirone-induced changes of electrolytes, SBP and plasma osmolality.

Effects of repeated restraint stress on serum electrolytes in ethanol-treated and water-treated rats.

The present study was designed to evaluate the effects of simultaneous ethanol administration (10%, v/v), and restraint stress (2 hrs/day for 5 day) on serum electrolytes. This restraint stress decreases serum concentration of Na(+), K(+), Ca(2+), phosphorus, and chloride. Ethanol treatment also decreased Na(+), K(+), Ca(2+), phosphorus, and chloride concentration. The decrease in Ca(2+) and phosphorus levels was greater for ethanol-treated restrained than water-treated restrained rats. Ethanol did not affect serum Mg(2+) while it was increased in restrained water-treated rats. Ethanol-treated restrained rats exhibited less serum Mg(2+) than ethanol-treated unrestrained or water-treated restrained rats. Possible mechanism involved in restraint or ethanol-induced changes of electrolytes is discussed. In conclusion, the result of this study suggest that alteration of serum electrolyte caused by repeated restrained in water-treated and ethanol-treated rats could possibly occur due to an increase in sympathetic activity leading to enhanced excretion of these electrolytes.

Role of serotonin-1A receptors in restraint-induced behavioral deficits and adaptation to repeated restraint stress in rats.

8-hydroxy-2-(di-n-propylamino) tetralin (8-OH-DPAT), a selective 5-hydroxy-tryptamine (5-HT; serotonin)-1A agonist was used to evaluate the role 5-HT-1 A receptors in restraint-induced behavioral deficits and adaptation to repeated restraint stress in rats. Animals were injected with 8-OH-DPAT at a dose of 0.25 mg/kg 1 h before exposing to an episode of 2 h/day restraint stress daily for 5 days. Effects of drug administration and restraint stress on 24 h cumulative food intakes were monitored daily. Intensity of 8-OH-DPAT-induced serotonin syndrome was also monitored each day before submitting animals to the episode of stress. Exposure to the first episode of 2 h restraint stress resulted in a decrease in 24 h cumulative food intake and an attenuation of 8-OH-DPAT-induced serotonin syndrome monitored next day. The deficits attenuated following 2nd and 3rd 2 h/day restraint were not observed following the 4th and 5th 2 h/day restraint. The decreases of food intake following 1st and 2nd day restraint sessions were smaller in 8-OH-DPAT than saline-injected animals. Administration of 8-OH-DPAT on day 6 elicited comparable serotonin syndrome in unrestrained and repeatedly restrained groups. Brain 5-HT metabolism decreased in unrestrained but not repeatedly restrained animals. The results suggest that a decrease in serotonergic neurotransmission is involved in restraint-induced behavioral deficits while a normalization of serotonin neurotransmission due to desensitization of somatodendritic 5-HT-1A receptors may help cope with the stress demand to produce adaptation to stress.

Intraerythrocyte and serum electrolytes in diabetic patients with hypertension.

OBJECTIVE: To determine the serum and intraerythrocyte concentrations of vasoactive ions in patients of diabetes mellitus of either gender with hypertension. DESIGN: Cross-sectional study. PLACE AND DURATION OF STUDY: The Department of Biochemistry, University of Karachi, from May-June 2002. PATIENTS AND METHODS: The study was conducted on 48 volunteers. Out of 48, 24(12 men and 12 women) were hypertensive patients with diabetes mellitus. Remaining (12 men and 12 women) were normal healthy subjects. Biochemical estimations were done by flame photometry and spectrophotometry. Data were analyzed by Two-way ANOVA followed by Newman-Keuls test. RESULTS: A decrease in serum concentrations of sodium, calcium, magnesium, phosphorus, chloride and intraerythrocyte potassium and an increase in the levels of glucose, haematocrit and intraerythrocyte sodium was observed in both male and female patients with diabetes mellitus and hypertension. No significant changes were observed in serum potassium levels. CONCLUSION: The results suggest that dysregulations of electrolyte balance caused by hyperinsulinemia or altered glucose metabolism may lead to hypertension.

Computer aided conformational analysis of sulfonated azo dyes diammonium orange G (C16H10N2O7S2 (NH4) x 4H2O.

The present work describes the conformational analysis of diammonium orange G (C16H10N2O7S2 (NH4) x 4H2O) by using Kitaigorodsky function. The minimum potential energy was found to be -0.0099839 at omega1 = 16 degrees and omega2 = 360 degrees.

Somatodendritic and postsynaptic serotonin-1A receptors in the attenuation of haloperidol-induced catalepsy.

The mechanism by which stimulation of somatodendritic and/or postsynaptic 5-hydroxytryptamine (5-HT, serotonin)-1A receptor could attenuate acute Parkinsonian-like effects of typical antipsychotics is investigated by comparing the anticataleptic and neurochemical effects of 8-hydroxy-2-di-n-propylaminotetralin (8-OH-DPAT) and buspirone in rats injected with haloperidol. Cataleptic effects of a submaximal dose (1 mg/kg) of haloperidol were attenuated more by prior administration of 8-OH-DPAT (0.25 mg/kg) than buspirone (1 mg/kg). Striatal 5-HT metabolism decreased more in buspirone- than 8-OH-DPAT-injected animals. Administration of haloperidol did not alter 5-HT metabolism in saline-, 8-OH-DPAT- or buspirone-injected animals. Dopamine decreased and its metabolite homovanillic acid (HVA) increased in the striatum of rats injected with buspirone. Effects of 8-OH-DPAT on dopamine metabolism were not significant. Haloperidol-induced increases of dopamine metabolites were attenuated by prior administration of 8-OH-DPAT, but not buspirone. The mechanism by which stimulation of somatodendritic as well as postsynaptic 5-HT-1A receptors could attenuate haloperidol-induced catalepsy is discussed. The findings have potential implications in the treatment of schizophrenia and motor behavior.

Serotonin and serotonin 1-A receptors in the failure of ethanol-treated rats to adapt to a repeated stress schedule.

OBJECTIVE: The effects of repeated-restraint stress on brain 5-hydroxytryptamine; serotonin (5-HT) metabolism and functional responses to a selective 5-HT-1A agonist, 8-hydroxy-2-(di-n-propylamino) tetralin (8-OH-DPAT), are compared in water- and ethanol-treated rats. METHOD: Locally bred male water- or ethanol-treated rats restrained 2 hours per day for 6 days were killed, and whole brains were collected for the neurochemical analysis by high performance liquid chromatography with electrochemical detection (HPLC-EC). In a separate experiment 8-OH-DPAT was injected in water- and ethanol-treated rats to compare elicited hyperactivity syndrome (a postsynaptic response) and effectiveness of the drug in reducing brain 5-HT synthesis (a presynaptic response). RESULTS: A single episode of 2-hour restraint stress decreased 24-hour cumulative food intake in both water- and ethanol-treated rats. Following repeated restraint stress of 2 hours per day for 5 days, the decreases were present in ethanol- but not water-treated rats. The sixth episode of 2-hour restraint stress did not alter brain tryptophan 5-HT and 5-hydroxyindoleacetic acid (5-HIAA) concentrations in water-treated repeatedly restrained rats but decreased tryptophan and increased 5-HT concentration in ethanol-treated rats. Ethanol-treated unrestrained and ethanol-treated repeatedly restrained rats exhibited higher levels of tryptophan 5-HT and 5-HIAA than their respective water-treated controls. Injecting 8-OH-DPAT at a dose of 0.25 mg/kg elicited comparable hyperactivity syndrome in water- and ethanol-treated rats but decreased 5-HT synthesis more in ethanol-treated than in water-treated rats. CONCLUSIONS: The present study shows that ethanol administration for 2 to 3 weeks, although it increases brain 5-HT metabolism, impairs adaptation by increasing the effectiveness of negative feedback control over 5-HT synthesis.

Neurochemical and extra pyramidal effects of atypical neuroleptic clozapine in rats.

In view of a possible role of serotonin (5-hydroxytryptamine, 5-HT) and dopamine (DA) in neuroleptic-induced muscle rigidity and catalepsy, the present study is designed to investigate the neurochemical and extrapyramidal effects of atypical antipsychotic/neuroleptic drug i.e., Clozapine (CZP) on the metabolism of serotonin and dopamine particularly in the caudate (a region of the brain involved in the control of movement), accumbens and rest of the rat brain. Interaperitoneal (i.p) injections of CZP at doses of 5.0 & 10 mg/kg decreased significantly (p<0.01) locomotor activity in familiar (home cage) environment. CZP produced a significant (P<0.01) cataleptic response only at doses of 10 mg/kg used. Maximal cataleptic effects in rats occurred at high doses of CZP. Acute administration of CZP significantly (p<0.01) decreased levels of NA in accumbens at all the doses used. Significant increases (p<0.01) in the levels of NA observed in rest of the brain only at moderate dose (5 mg/kg) of CZP. Results showed significant (p<0.01) increases in the levels of caudate DA following the administration of CZP at 10 mg/kg. However administration of CZP at all the doses produced similar significant (p<0.01) increases in the levels of HVA in all the regions of the rat brain. Overall insignificant effects of CZP occurred on brain regional TRP. However, plasma TRP significantly (p<0.01) increased at 2.5 mg/kg dose of CZP. Administration of CZP at doses of 2.5 and 10 mg/kg significantly (p<0.01) decreased 5-HT levels in the rest of the brain. Administration of CZP produced insignificant (p>0.05) effects on 5-HIAA levels in the caudate and accumbens regions but CZP at doses of 2.5 and 5 mg/kg significantly (p<0.01) decreased 5-HIAA levels in the rest of the brain. Neurochemical and extrapyramidal effects of atypical antipsychotic (clozapine) are discussed in relation to a potential therapeutic profile in rats.

Electrolyte content of serum, erythrocyte, kidney and heart tissue in salt induced hypertensive rats.

The effect of salt load on the systolic blood pressure (SBP) and electrolyte levels of serum, erythrocyte, kidney and heart tissue was studied in rats. NaCl treatment increased sodium (5.69 +/- 0.4 mmol/L p < 0.001, 149.8 +/- 4.0 mEq/L, p < 0.001) and decreased potassium (112.6 +/- 2.4 mmol/L p < 0.001, 5.0 +/- 0.2 mEq/L, p < 0.001) in red cell and serum respectively. A decreased level of serum magnesium (1.4 +/- 0.3 mEq/L, p < 0.005) was observed. Sodium content was increased in both heart (39.93 +/- 2.9 mumol/g, p = n.s) and kidney tissues (44.39 +/- 0.5 mumol/g, p < 0.001). A pronounced increase in intracellular calcium (2.54 +/- 0.2 mumol/g, p < 0.001) and a decrease of magnesium content (6.05 +/- 0.8 mumol/g, p < 0.001) was observed in kidney tissue after treatment. The results suggested that marked changes in electrolyte levels of erythrocytes, serum, heart and kidney tissues in NaCl loaded rats may play a definite role in the development of salt induced hypertension.

Stress and hypertension: role of serum, red cell and tissue electrolytes.

The role of stress in the precipitation of hypertension is often described in clinical studies, although the underlying mechanism remains unknown. The present study concerns the role of electrolytes in stress induced hypertension in rats. Acute immobilization stress of one hour elevated systolic blood pressure (SBP) in rats. Restraint induced blood pressure elevation was associated with increased sodium concentration in the red cells, heart and kidney, and decreased potassium in the red cells. Magnesium concentration increased and calcium concentration decreased in the serum. Increases of calcium and decreases of magnesium were also observed in the heart and kidney tissues. The results may help toward an understanding of the relationship between hypertension and electrolyte homeostasis. A possible role of Na(+)-K(+)-ATPase activity leading to observed changes of electrolytes or vice versa is discussed.

24h withdrawal following repeated administration of caffeine attenuates brain serotonin but not tryptophan in rat brain: implications for caffeine-induced depression.

Caffeine injected at doses of 20, 40 and 80 mg/kg increased brain levels of tryptophan, 5-hydroxytryptamine (5-HT) and 5-hydroxyindole acetic acid (5-HIAA) in rat brain. In view of a possible role of 5-HT in caffeine-induced depression the effects of repeated administration of high doses of caffeine on brain 5-HT metabolism are investigated in rats. Caffeine was injected at doses of 80 mg/kg daily for five days. Control animals were injected with saline daily for five days. On the 6th day caffeine (80 mg/kg) injected to 5 day saline injected rats increased brain levels of tryptophan, 5-HT and 5-HIAA. Plasma total tryptophan levels were not affected and free tryptophan increased. Brain levels of 5-HT and 5-HIAA but not tryptophan decreased in 5 day caffeine injected rats injected with saline on the 6th day. Plasma total and free tryptophan were not altered in these rats. Caffeine-induced increases of brain tryptophan but not 5-HT and 5-HIAA were greater in 5 day caffeine than 5 day saline injected rats. The findings are discussed as repeated caffeine administration producing adaptive changes in the serotonergic neurons to decrease the conversion of tryptophan to 5-HT and this may precipitate depression particularly in conditions of caffeine withdrawal.

Aspiration pneumonia as a cause of death.

This study of aspiration pneumonia is based on postmortem examinations carried out over a decade from 1979 to 1988 at York, on subjects of all ages and both sexes. The purpose of this study was not only to analyse the autopsy findings, but also to find out the real prevalence, the major causes leading to aspiration pneumonia, and its associated clinical features.