Fasting leptin and glucose in normal weight, over weight and obese men and women diabetes patients with and without clinical depression

A large number of diabetes patients suffer from major depression and are at high risk of mortality. In view of a role of leptin in diabetes, depression and energy homeostasis, the present study concerns circulating levels of leptin in different BMI groups of un-depressed and depressed diabetes patients. Six hundred thirty male and female patients with a primary diagnosis of diabetes were grouped according to BMI and with or without clinical symptoms of depression. Age matched healthy, normal weight male and female volunteers without clinical symptoms of depression or diabetes were taken as controls. Blood samples were obtained after an overnight fast of 12 h. Serum was stored for the determination of leptin and glucose. We found that there were more female than male diabetes patients with comorbid depression. Fasting leptin was higher in normal weight non-diabetes women than men; but comparable in normal weight men and women diabetes patients. Fasting glucose levels were higher in diabetes than non diabetes groups; values were comparable in men and women. Depression was associated with a decrease and increase in leptin respectively in normal-overweight and obese men and women diabetes patients. Glucose levels were also higher in obese depressed than un-depressed diabetes patients. The results suggested that the female gender is at greater risk to comorbid diabetes with depression. Adipo-insular axis plays an important role in diabetes, associated depression and in the greater risk of the female gender to comorbid diabetes with depression.

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.

Pterandric Acid – its Isolation, Synthesis and Stereochemistry

Some plant families have a specialized type of pollination system, with floral lipid rewards for pollinators, which is common. In neotropical Malpighiaceae species like Pterandra pyroidea, this specialized type of pollination system is apparently shifting from floral oils/lipids to pollen reward. Mass spectrometric analysis (GC/MS-EI) indicated that P. pyroidea floral oil has a unique chemical composition, i.e., few fatty acid constituents possessing acetoxy groups at positions 5 and 7, which is distinct from the other floral oils of sympatric Malpighiaceae species. The structure of the major floral oil constituent, a novel fatty acid, a nti-5,7-diacetoxydocosanoic acid, was confirmed based on synthesis, mass fragmentation, and 1H and 13C NMR analyses; the compound is herein named pterandric acid.

Pterandric acid--its isolation, synthesis and stereochemistry

Some plant families have a specialized type of pollination system, with floral lipid rewards for pollinators, which is common. In neotropical Malpighiaceae species like Pterandra pyroidea, this specialized type of pollination system is apparently shifting from floral oils/lipids to pollen reward. Mass spectrometric analysis (GC/MS-EI) indicated that P. pyroidea floral oil has a unique chemical composition, i.e., few fatty acid constituents possessing acetoxy groups at positions 5 and 7, which is distinct from the other floral oils of sympatric Malpighiaceae species. The structure of the major floral oil constituent, a novel fatty acid, anti-5,7-diacetoxydocosanoic acid, was confirmed based on synthesis, mass fragmentation, and 1H and 13C NMR analyses; the compound is herein named pterandric acid.

Inhibition of immobilization stress-induced anorexia, behavioral deficits, and plasma corticosterone secretion by injected leptin in rats

Leptin, originally identified as an anti-obesity hormone, also has an important role in the regulation of mood and emotion. The present study was designed to monitor effects of injected leptin on immobilization stress-induced anorexia, behavioral deficits, and plasma corticosterone secretion in rats. Exposure to 2 h immobilization stress decreased food intake and body weight in saline-injected animals. Animals exposed to open field, elevated plus maze, and light-dark transition tests the day following immobilization exhibited anxiety-like behavior. Leptin injected at doses of 0.1 and 0.5 mg/kg also decreased food intake and body weight in unstressed animals and elicited anxiolytic effects at dose of 0.5 mg/kg, monitored on the following day. Immobilization-induced decreases in food intake, body weight, as well as stress-induced behavioral deficits in the open field, elevated plus maze, and light-dark transition test were reversed by exogenous leptin in a dose-dependent (0.1-0.5 mg/kg) manner. Acute exposure to 2 h immobilization produced a fourfold rise in plasma levels of corticosterone. Animals injected with leptin at a dose of 0.1 mg/kg, but not at dose of 0.5 mg/kg, exhibited a marginal increase in plasma corticosterone. Immobilization-induced increases of plasma corticosterone were reversed by leptin injected at doses of 0.1 or 0.5 mg/kg. The data suggest that exogenous leptin can reduce stress perception, resulting in an inhibition of stress effects on the activity of hypothalamic-pituitary-adrenal axis and behavior. The reported pharmacological effects of leptin represent an innovative approach for the treatment of stress-related disorders.

Pterandra pyroidea: a case of pollination shift within neotropical Malpighiaceae

BACKGROUND AND AIMS

Most Neotropical species of Malpighiaceae produce floral fatty oils in calyx glands to attract pollinating oil-collecting bees, which depend on this resource for reproduction. This specialized type of pollination system tends to be lost in members of the family that occur outside the geographic distribution (e.g. Africa) of Neotropical oil-collecting bees. This study focused on the pollination ecology, chemical ecology and reproductive biology of an oil flower species, Pterandra pyroidea (Malpighiaceae) from the Brazilian Cerrado. Populations of this species consist of plants with oil-secreting (glandular) flowers, plants with non-oil-secreting flowers (eglandular) or a mix of both plant types. This study specifically aims to clarify the role of eglandular morphs in this species.

METHODS

Data on pollinators were recorded by in situ observations. Breeding system experiments were conducted by isolating inflorescences and by enzymatic reactions. Floral resources, pollen and floral oils offered by this species were analysed by staining and a combination of various spectroscopic methods.

KEY RESULTS

Eglandular flowers of P. pyroidea do not act as mimics of their oil-producing conspecifics to attract pollinators. Instead, both oil-producing and oil-free flowers depend on pollen-collecting bees for reproduction, and their main pollinators are bumble-bees. Floral oils produced by glandular flowers are less complex than those described in closely related genera.

CONCLUSIONS

Eglandular flowers represent a shift in the pollination system in which oil is being lost and pollen is becoming the main reward of P. pyroidea flowers. Pollination shifts of this kind have hitherto not been demonstrated empirically within Neotropical Malpighiaceae and this species exhibits an unusual transition from a specialized towards a generalized pollination system in an area considered the hotspot of oil-collecting bee diversity in the Neotropics. Transitions of this type provide an opportunity to study ongoing evolutionary mechanisms that promote the persistence of species previously involved in specialized mutualistic relationships.

Acute administration of clozapine and risperidone altered dopamine metabolism more in rat caudate than in nucleus accumbens: a dose-response relationship

The present study compares the extrapyramidal and neurochemical effects of clozapine and risperidone in rat caudate (corpus striatum) and nucleus accumbens (ventral striatum) dose-dependently. Animals injected with clozapine (2.5, 5.0 and 10.0 mg/kg IP) or risperidone (1.0, 2.5 and 5.0 mg/kg IP) in acute were sacrificed 1 h later to collect brain samples. Extrapyramidal side effects (EPS) in terms of locomotor activity and catalepsy were monitored in each animal after the drug or vehicle administration. Maximum cataleptic potentials were found only at high doses of clozapine (10.0 mg/kg; 60%) and risperidone (5.0 mg/kg; 100%). Neurochemical estimations were carried out by HPLC-EC. Both drugs at all doses significantly (p<0.01) increased the concentration of homovanillic acid (HVA), a metabolite of DA, in the caudate nucleus and decreased in nucleus accumbens. Levels of Dihydroxyphenylacetic acid (DOPAC) significantly (p<0.01) increased in the caudate by clozapine administration and decreased in the nucleus accumbens by the administration of both drugs in a dose-dependent manner. 5-Hydroxyindoleacetic acid (5-HIAA), the predominant metabolite of serotonin significantly decreased in the caudate and nucleus accumbens in a similar fashion. Levels of tryptophan (TRP) were remained insignificant in caudate and nucleus accumbens by the injections of two drugs. In caudate, clozapine and risperidone administrations significantly (p<0.01) decreased HVA/DA ratio and increased DOPAC/DA ratio in nucleus accumbens at all doses. The findings suggest the evidence for DA/5-HT receptor interaction as an important link in the lower incidence of EPS. The possible role of serotonin_1A receptors in the pathophysiology of schizophrenia is also discussed.

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.

Behavioral effects of 1-(m-chlorophenyl)piperazine (m-CPP) in a rat model of tardive dyskinesia

The present study was designed to monitor the responsiveness of 5-hydroxy tryptamine (5-HT)-2C receptor in rats treated with haloperidol exhibiting tardive dyskinesia (TD). Results show that haloperidol injected at a dose of 1 mg/kg twice a day for two weeks elicited vacuous chewing movements (VCMs). Which increased in a time dependent manner following the drug administration for 3-5 weeks. The behavioral effects of 1-(m-chlorophenyl)piperazine (m-CPP) a 5-HT-2C and 5-HT-1B agonist were monitored 2 days after 5 weeks of saline or haloperidol administration. The results show that hypophagic as well as anxiogenic-like effects of m-CPP are greater in repeated haloperidol than repeated saline injected animals, while hypolocomotive effects of m-CPP are not different in repeated saline and haloperidol injected animals. Results are discussed in the context of role of 5-HT-2C receptors in the regulation of the activity of dopaminergic neuron and its possible impact on elicitation of TD.

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.

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.

Effect of NSAIDS on serum electrolytes and osmolality

Rabbits and rats were injected two Nonsteroidal anti-inflammatory drugs (aspirin 300 mg/kg or indomethacin 3 mg/kg) intraperitoneally. One hour after injection blood was analyzed for serum electrolytes and osmolality. Administration of both aspirin and indomethacin in rabbits and rats caused increase in serum sodium, potassium, calcium, chloride, magnesium, phosphorus and osmolality. Results suggest the marked similarity in the action of aspirin and indomethacin on electrolytes and osmolality. It is concluded that the ingestion of aspirin and indomethacin can have a major effect on serum electrolytes and osmolality that may influence the interpretation of clinical data in patients taking these drugs.

Three cases of gangrenous ischaemic colitis

The concept of ischaemic colitis is relatively recent. It is more common in the elderly than is realised, and results from reduction or occlusion of the blood supply to the colon. Three cases of ischaemic colitis in its gangrenous form are reported. The patients died despite all therapeutic measures. Necropsy revealed full thickness gangrene of the involved segment of the colon.

Effect of ethanol on serum electrolytes and osmolality

Rats and rabbits were injected ethanol 2 g/kg intraperitoneally. One hour after injection blood was analyzed for serum electrolytes and osmolality. Administration of ethanol caused decrease in serum sodium (p less than 0.0005), potassium (p less than 0.0005), calcium (p less than 0.0005), chloride (p less than 0.005), magnesium (p less than 0.0005) in rabbits. Further studies of intraperitoneal administration of ethanol in rats showed decrease in concentration of sodium (p less than 0.025), potassium (p less than 0.025), calcium (p less than 0.01) chloride (p less than 0.005) magnesium (p less than 0.005), phosphorus (p less than 0.025) and glucose (p less than 0.005). Administration of ethanol caused an increase in serum osmolality in both rabbits and rats (p less than 0.005, p less than 0.05). It is concluded that ethanol ingestion is probably the commonest cause of the hyperosmolar state. Although the osmotic and sedative effects of ethanol are pharmacologically unrelated, the presence of ethanol should be considered in comatose patients in whom the measured plasma osmolality appreciably exceeds that predicted on the basis of plasma glucose, urea and electrolytes concentration.

X-ray diffraction studies on the structure of alpha-chitin

The structure for alpha-chitin originally proposed by Carlström is generally considered to be the true structure. However, it fails to account for several remaining problems of chitin structure which include a complete explanation of the infrared spectrum and also the different properties of alpha- and beta-chitins. We have reexamined the structure by X-ray diffraction using automatic rigid subunit least-squares refinement and also the difference Fourier method. The R-value was reduced from 0.31 to 0.22 by a number of small modifications to the structure proposed by Carlström. Consideration of symmetry suggests that two distinct types of statistical modifications could be present in the structure, both of which would allow complete intersheet hydrogen bonding between O6H groups within the general framework of Carlström structure. The X-ray results give some support to one of these modifications. However, it is predictable that both would affect the X-ray diffraction only marginally so that a clear proof lies beyond the present sensitivity of the method. The proposed extra hydrogen bonding in alpha-chitin provide the first clear explanation for the different properties of these kinds of chitin.

The kinetics of the decarboxylation of β-resorcylic acid in catechol

Kinetic data are reported for the decarboxylation of β-resorcylic acid in resorcinol and catechol for the first time. The reaction is first order. The observation supports the view that the decomposition proceeds through an intermediate complex mechanism. The parameters of the absolute reaction rate equation are calculated.