Time dependent distribution of [203Hg] mercuric nitrate in the subcellular fractions of rat and fish liver

Cytotoxicity of inorganic mercury to the liver of two species, Anabas testudineus and Sprague Dawley male rat was evaluated. Distribution kinetics of this metal in the different hepatic subcellular fractions were followed for 48 h after a single injection of [203Hg] mercuric nitrate at a dose of 4mg/kg b.w. Interaction of this metal with protein, DNA and RNA was also studied. In rat, nuclear and lysosomal fractions showed a significant increase in the protein content, while in fish, the amount of protein increased in all fractions except microsome. Comparatively more mercury was bound to protein in fish during the later phase of treatment. Retention of mercury in nuclear DNA of rat gradually declined from 15 min to 48 h of treatment, while, mitochondrial DNA binding to mercury increased from 15 min to 2 h of post injection and then declined in the later phase of the experiment. Such a biphasic binding pattern of mercury was shown by both the nuclear and mitochondrial DNA of the fish. The nuclear RNA of rat and mitochondrial and cytosolic RNA of both test species also showed a biphasic pattern of mercury binding, however, with a higher rate of binding in fish at the later phase of the experiment. The present study thus highlights that (a) mercury follows a definite distribution pattern in the subcellular fractions of the liver in both animal species, (b) cytosol is the major site of mercury accumulation.

AUSTRALIA ANTIGEN (HBsAG) IN INSTITUTIONALISED SCHIZOPHRENICS

In a study of sixty institutionalist Schizophrenic patients, sixty chronic schizophrenic outpatients and an equal number of age and sex matched normal controls from the same regional background, the prevalence of HBsAG was six, one and zero respectively. Institutionalized schizophrenic patients are a high risk group for hepatitis B virus infection.

Post - cataractomy delirium : a two year prospective study

A two year prospective study of 221 consecutive inpatients undergoing cataractomy revealed the incidence of post-cataractomy delirium to be 1.8%. While in one case the delirium was due to anticholinergic toxicity, in the remaining three cases no organic cause was evident. Sensory deprivation was present in two patients. Preventive measures for the condition are discussed.

Eating epilepsy: a study of twenty cases

Twenty cases of eating epilepsy have been studied over a period of 5 years (1985-1989). Males outnumbered females (4:1). Heavy meal comprising conventional Indian diet (viz, rice, vegetables, etc), was found to be the most important provocating factor (14 out of 20 cases). The attacks occurred at lunch time in most cases (15). Thirteen cases had generalised seizures. Electro-encephalogram showed focal changes in 10 cases, generalised changes in 6 cases, while 4 cases had normal electro-encephalogram. Computerised tomography scan was normal in all the cases (7) when it was done.

Transmission of viable Mycobacterium leprae by Aedes aegypti from lepromatous leprosy patients to the skin of mice through interrupted feeding

Female Aedes aegypti which took partial blood meals from the skin lesions of untreated lepromatous leprosy (LL) patients were then allowed to continue feeding on 72-96-hr-old Swiss albino suckling mice (Rockefeller strain). The bitten portion of skin was removed, divided into two parts and processed for the extraction of bacilli by two different methods using chloroform and petroleum ether. The proboscis of some of the fed mosquitoes was dissected out and examined for viable bacilli (stained by fluorescein diacetate and ethidium bromide) and acid-fast bacilli (AFB). Out of 50 probosces dissected 45 were found positive for AFB, with bacillary counts ranging up to 246 (average 40.20 +/- SD 41.80) per proboscis. The average percentage of viable bacilli (green solid) in the probosces immediately after feeding on LL patients was 43.90 and thereafter it decreased gradually to 3 on the seventh day. In the petroleum ether extract of mouse skin viable bacilli were observed in numbers up to 37 (average 15.25 +/- SD 10.25) per smear. The number of fluorescing bacilli (green and red) correlated with the total number of AFB.

Amplification of CCl4 toxicity by chlordecone: destruction of rat hepatic microsomal cytochrome P-450 subpopulation

Previous work has established marked amplification of CCl4 hepatotoxicity by prior exposure to chlordecone (CD). Since CCl4 is toxic by virtue of its bioactivation by the hepatomicrosomal cytochrome P-450 (cyt P-450) system, which is in turn destroyed, our first interest was to determine if cyt P-450 isozymes were selectively destroyed in this interaction. CoCl2 also decreased hepatic P-450 contents, so our other interest was to observe whether CoCl2 selectively decreased or spared CCl4 metabolizing P-450 enzymes. Solubilized hepatic microsomes from variously treated rats were used. The treatment protocol was dietary CD (10 ppm, for 15 d), and CCl4 (100 microliters/kg, ip). The treatments were CD alone, CCl4 alone, CD + CCl4 and with or without CoCl2 (60 mg/kg/d, sc for 2 d) treatment on d 13 and 14 of the dietary protocol. The control group received normal diet and corn oil vehicle. The key mixed-function oxidase (MFO) parameters measured were microsomal protein, cyt P-450 content, and aminopyrine demethylase (APD). Decrease of P-450 levels ranged from 2.2-fold (CD + CCl4) to 1.3-fold (CD + CoCl2). APD activity decreased by 48 and 26.6% in CD + CCl4 and CD + CoCl2 treatments, respectively. Using an anion-exchange high-performance liquid chromatography (HPLC) column, solubilized microsomal hemoproteins were resolved into five peaks. The P-450 content associated with each peak was determined. In CD rats there was slight increase in peak heights, whereas peak heights in CCl4 and control treatments were similar. CoCl2 decreased all peaks, the decrease of peak I being maximal. In CD + CCl4 treatment, absence of peaks II and III was noted. Microsomal proteins stained for heme showed decreased staining intensity of hemo-protein bands, particularly band 4 (MW 52,000), which was absent in CD + CCl4 interaction. These findings suggest that (1) CoCl2 does not selectively decrease or spare any P-450 isozymes and (2) CD + CCl4 interaction does destroy specific P-450 isozymes.

Thyroidal stimulation of tubulin and actin in primary cultures of neuronal and glial cells of rat brain

The influence of triiodothyronine (T3) on the level of tubulin and other proteins in primary cultures of neuronal (N) and glial (G) cells from rat brain has been investigated. Quantitation of tubulin by [3H]colchicine binding assay revealed that when cells from 1 day rat brain were cultured for 18 hr with physiological doses (0.5-5 nM) of T3, the hormone elicited 35-40% increase in the soluble (30,000 g supernatant) tubulin content of G cells only. This stimulation was age-dependent and occurred neonatally at a time corresponding to the onset of synaptogenesis. In mouse and chick brain also, [3H]colchicine binding assay showed a similar selective stimulation of the soluble tubulin content of G cells by T3 with virtually no effect on N cells. However, SDS-polyacrylamide gel electrophoresis of the total proteins in the 30,000 g supernatants from N and C cells of rat brain, labeled for 18 hr with [14C]leucine in the presence of T3, revealed that T3 elicited 2-3-fold enhancement of radiolabeled tubulin in the N cells which is relatively greater than the 1.5-fold increase seen in the G cells. Analysis of the autoradiograms of these labeled proteins also revealed that in addition to tubulin, T3 stimulated the accumulation of radiolabeled actin by 1.5- and 2-fold in N cells and G cells respectively. Similar electrophoretic analysis of the solubilized labeled proteins in the 30,000 g pellets from N and G cells indicated that the failure to detect the stimulation of tubulin in the 30,000 g supernatants from N cells by [3H]colchicine binding assay could be at least partly due to rapid translocation of the dimeric soluble tubulin into insoluble membrane fractions or due to presence of higher oligomeric forms of tubulin which are insensitive to [3H]colchicine binding assay.

Cardiogenic shock with imipramine

A 35 years old physically healthy individual, being treated far depression with imipramine and electroplexy, developed cardiogenic shock which was managed successfully with inotropic support. The case is presented to highlight a rare and potentially fatal side effect of tricyclic anti-depressants.

Monosymptomatic hypochondriacal psychosis-2 case reports

Two patients with monosymptoniatic hypochondriacal psychosis are reported and the condition is briefly discussed.

Transmission of Mycobacterium leprae from lepromatous leprosy patients to the skin of mice through intermittent feeding

Batches of hungry Aedes aegypti mosquitoes which partially sucked blood from the skin lesions of proved untreated lepromatous leprosy (LL) patients were allowed immediately to feed on a portion of the skin of a cleanly shaved swiss mouse. The portion of the skin was cut, homogenized on the same day and extracted with chloroform. Out of 10 extracts, stained for acid fast bacilli (AFB), Mycobacterium leprae were demonstrated in eight, indicating transfer of bacilli mechanically to the biting spot through intermittent feeding. Out of 50 probosces dissected and stained for AFB, M. leprae were demonstrated in 45.

The dexamethasone supperssion test in endogenous depression

In 34 patients of endogenous depression and 30 normal controls, the dexamethasone suppression test (DST) had a sensitivity of 67.6%, a specificity of 93.3% and a positive predictive power of 92%, which compares favourably with other diagnostic tests in clinical medicine. DST non-suppressors were significantly more depressed as compared to DST suppressors, had a higher incidence of suicidal attempts and past and family history of depression, needed electroconvulsive therapy more often, but showed a better response to therapy. Though the claim of the DST being a specific biological marker for endogenous depression remains controversial, it is an useful investigative tool for the diagnosis and treatment of endogenous depression.

Comparison of the inhibitory effects of some compounds present in crude oils on rat platelet aggregation: role of intra- and extra- cellular calcium

In vitro addition of some representative aliphatic, aromatic or heterocyclic compounds present in petroleum crude oils to washed rat platelets resulted in a concentration-dependent inhibition of aggregation induced by ADP or thrombin. Increasing concentration of extracellular Ca2+ did not alter the pattern of inhibition. ADP-induced intracellular Ca2+ mobilization was unaffected by most of the compounds tested. However, Ca2+ uptake was significantly inhibited when platelets were preincubated with these agents. This suggests that some components of crude oil may inhibit platelet aggregation by bringing about alterations in the platelet plasma membrane.

Inhibition of rat platelet aggregation by a Prudhoe Bay crude oil and its aliphatic, aromatic, and heterocyclic fractions

Washed platelets isolated from rats 24 hr after oral treatment with a Prudhoe Bay crude oil (PBCO) showed a substantial inhibition of aggregation induced by ADP, arachidonic acid, or epinephrine. In vitro addition of a dimethyl sulfoxide extract of PBCO or its aliphatic, aromatic, or heterocyclic fractions to washed platelets also resulted in an inhibition of aggregation. ADP release was inhibited in platelets to which an extract of PBCO or its fractions were added in vitro or in platelets isolated from rats treated in vivo with PBCO. Thromboxane B2 release was increased in platelets isolated from rats intubated with PBCO or in platelets to which a dimethyl sulfoxide extract of the aromatic or heterocyclic fraction was added. However, thromboxane B2 release was inhibited in platelets to which PBCO or the aliphatic fraction extracts were added. The results indicate that PBCO inhibits platelet aggregation presumably by bringing about alterations in the platelet plasma membrane. Inhibition of ADP release could contribute to the inhibition of aggregation but thromboxane B2 is believed not to play a significant role.