Antiangiogenic activity of zinc and zinc-sorafenib combination using the chick chorioallantoic membrane assay: A descriptive study

Aim

Zinc, a trace element, is known for downregulating several proangiogenic growth factors and cytokines. However, its antiangiogenic activity is not adequately studied. The present study was aimed to evaluate the possible antiangiogenic activity of zinc via the chick chorioallantoic membrane (CAM) assay. Furthermore, the antiangiogenic activity of the combination therapy of zinc with various doses of sorafenib, a tyrosine kinase inhibitor, was evaluated.

Materials and Methods

A pilot study was initially conducted so as to select suitable doses of zinc and sorafenib. The antiangiogenic activity after combining zinc 2.5 μg/embryo with sorafenib 1 and 2 μg/embryo was also evaluated. The antiangiogenic activity was quantified in terms of total length of blood vessels, number of junctions, number of branching points, and mean length of the blood vessels.

Results

Zinc 2.5 μg/embryo showed significant (P < 0.05) antiangiogenic activity, as compared to the control group. However, its effect was not comparable to that of sorafenib 2 μg/embryo. The combination of zinc 2.5 μg/embryo with sorafenib 2 μg/embryo did not show an additive/synergistic effect. The combination of zinc 2.5 μg/embryo with sorafenib 1 μg/embryo produced an antiangiogenic activity which was comparable (P > 0.05) to that of sorafenib 2 μg/embryo.

Conclusion

Zinc caused significant antiangiogenic activity in the CAM assay. The lack of addition/synergism in the zinc-sorafenib combination could have been due to the variability in the dose/ratio selection. Addition of zinc to sorafenib therapy could improve treatment tolerability, reduce cost of therapy, and reduce the emergence of drug resistance. Future mechanistic studies could identify the exact pharmacodynamics of zinc as an angiogenesis inhibitor.

Discovery of two novel laccase-like multicopper oxidases from Pleurotus citrinopileatus and their application in phenolic oligomer synthesis

BACKGROUND

Laccases and laccase-like multicopper oxidases (LMCOs) oxidize a vast array of phenolic compounds and amines, releasing water as a byproduct. Their low substrate specificity is responsible for their tremendous biotechnological interest, since they have been used for numerous applications. However, the laccases characterized so far correspond to only a small fraction of the laccase genes identified in fungal genomes. Therefore, the knowledge regarding the biochemistry and physiological role of minor laccase-like isoforms is still limited.

RESULTS

In the present work, we describe the isolation, purification and characterization of two novel LMCOs, PcLac1 and PcLac2, from Pleurotus citrinopileatus. Both LMCOs were purified with ion-exchange chromatographic methods. PcLac2 was found to oxidize a broader substrate range than PcLac1, but both LMCOs showed similar formal potentials, lower than those reported previously for laccases from white-rot fungi. Proteomic analysis of both proteins revealed their similarity with other well-characterized laccases from Pleurotus strains. Both LMCOs were applied to the oxidation of ferulic and sinapic acid, yielding oligomers with possible antioxidant activity.

CONCLUSIONS

Overall, the findings of the present work can offer new insights regarding the biochemistry and variability of low-redox potential laccases of fungal origin. Low-redox potential biocatalysts could offer higher substrate selectivity than their high-redox counterparts, and thus, they could be of applied value in the field of biocatalysis.

Attenuation of oxidative stress and neurotoxicity involved in the antidepressant-like effect of the MK-801(dizocilpine) in Bacillus Calmette-Guerin-induced depression in mice

Background The emerging line of research suggests that neuro-inflammation and oxidative stress are linked to the development of depression-like behavior. The tryptophan metabolizing enzyme, indolamine 2,3-dioxygenase (IDO), serves as an important interface between chronic inflammation and depression. IDO is induced by pro-inflammatory cytokines and diverts tryptophan towards the kynurenine pathway, decreasing serotonin synthesis. Further, the metabolites of kynurenine pathway increase brain oxidative stress and also cause N-methyl-D-aspartate (NMDA) receptor-mediated exitotoxicity. The resulting oxidative damage and dysfunction in glutamatergic neurotransmission alters the network connectivity of the brain, which may be the further mechanism for emergence of depression-like symptoms. Methods A depression-like illness was induced in mice by injecting Bacillus Calmette-Guerin (BCG) suspended in isotonic saline at a dose of 107 CFU I.P. The mice were then divided into different groups and were administered MK-801 or normal saline for the next 21 days, after which a battery of behavior and biochemical tests were conducted to assess them. Results The BCG group had significantly reduced sucrose preference index and an increase in immobility time in forced swim test (FST) and Tail Suspension Test (TST) as compared to the saline group. There was also a significant increase in the brain MDA levels and a decline in the brain GSH levels. The hippocampal tissue from the BCG group had significantly more comet cells than the saline group. The NMDA receptor antagonist, MK-801, was able to reverse the BCG-induced depression-like behaviour. MK-801 also showed significant decrease in brain oxidative stress but failed to show significant protection against BCG-induced neurotoxicity observed in comet assay. Conclusions The NMDA receptor antagonist, MK-801, mitigated BCG-induced, depressive-like behavior in mice by improving the sucrose preference and decreasing the duration of immobility time in TST and FST. The overall improvement in depression-like behavior was accompanied by a reduction in brain oxidative stress and comet cells, thus suggesting the antioxidant and neuroprotective action of MK-801.

Comparison of fluoxetine and 1-methyl-L-tryptophan in treatment of depression-like illness in Bacillus Calmette-Guerin-induced inflammatory model of depression in mice

BACKGROUND

The inflammatory response system has been implicated in the pathophysiology of major depression. The pro-inflammatory cytokines like interferon-γ induce the enzyme indoleamine-2,3-dioxygenase (IDO) of the kynurenine pathway of tryptophan metabolism. The induction of IDO reduces the availability of tryptophan for serotonin synthesis. Furthermore, the metabolites of kynurenine pathway have neurotoxic property, which along with decreased serotonin may account for depression-like illness.

METHODS

The aim of this study was to compare the effects of treatment with fluoxetine and 1-methyl-L-tryptophan (1-MT) on Bacillus Calmette-Guerin (BCG)-induced inflammatory model of depression in mice. Behavioral tests included locomotor activity, forced swim test (FST) and tail suspension test (TST). Oxidative stress was assessed by examining the levels of thiobarbituric acid reactive species (TBARS) and non-protein thiols (NP-SH) in homogenized whole brain samples. Comet assays were performed to assess neurotoxicity.

RESULTS

The results of this study demonstrate that BCG treatment resulted in an increase in duration of immobility in FST and TST as compared to the saline group. Further, it produced a significant increase in the brain TBARS levels and decrease in the brain NP-SH levels. The hippocampal tissue from BCG group had significantly more comet cells than the saline group. 1-MT and fluoxetine were able to reverse the BCG-induced depression-like behavior and the derangement in oxidative stress parameters. Fluoxetine and 1-MT also reversed the BCG-induced neurotoxicity in such mice.

CONCLUSIONS

1-Methyl-L-tryptophan exhibits antidepressant-like effect comparable to that of fluoxetine in treating BCG-induced depression-like behavior in mice.

Pharmacological characterization of the first in class clinical candidate PF-05190457: a selective ghrelin receptor competitive antagonist with inverse agonism that increases vagal afferent firing and glucose-dependent insulin secretion ex vivo

BACKGROUND AND PURPOSE

Ghrelin increases growth hormone secretion, gastric acid secretion, gastric motility and hunger but decreases glucose-dependent insulin secretion and insulin sensitivity in humans. Antagonizing the ghrelin receptor has potential as a therapeutic approach in the treatment of obesity and type 2 diabetes. Therefore, the aim was to pharmacologically characterize the novel small-molecule antagonist PF-05190457 and assess translational pharmacology ex vivo.

EXPERIMENTAL APPROACH

Radioligand binding in filter and scintillation proximity assay formats were used to evaluate affinity, and europium-labelled GTP to assess functional activity. Rat vagal afferent firing and calcium imaging in dispersed islets were used as native tissues underlying food intake and insulin secretion respectively.

KEY RESULTS

PF-05190457 was a potent and selective inverse agonist on constitutively active ghrelin receptors and acted as a competitive antagonist of ghrelin action, with a human Kd of 3 nM requiring 4 h to achieve equilibrium. Potency of PF-05190457 was similar across different species. PF-05190457 increased intracellular calcium within dispersed islets and increased vagal afferent firing in a concentration-dependent manner with similar potency but was threefold less potent as compared with the in vitro Ki in recombinant overexpressing cells. The effect of PF-05190457 on rodent islets was comparable with glibenclamide, but glucose-dependent and additive with the insulin secretagogue glucagon-like peptide-1.

CONCLUSIONS AND IMPLICATIONS

Together, these data provide the pharmacological in vitro and ex vivo characterization of the first ghrelin receptor inverse agonist, which has advanced into clinical trials to evaluate the therapeutic potential of blocking ghrelin receptors in obesity and type 2 diabetes.

Isotopic disequilibrium in Globigerina bulloides and carbon isotope response to productivity increase in Southern Ocean

Oxygen and carbon isotope ratios in planktonic foraminifera Globigerina bulloides collected from tow samples along a transect from the equatorial Indian ocean to the Southern Ocean (45°E and 80°E and 10°N to 53°S) were analysed and compared with the equilibrium δ¹⁸O and δ¹³C values of calcite calculated using the temperature and isotopic composition of the water column. The results agree within ~0.25‰ for the region between 10°N and 40°S and 75–200 m water depth which is considered to be the habitat of Globigerina bulloides. Further south (from 40°S to 55°S), however, the measured δ¹⁸O and δ¹³C values are higher than the expected values by ~2‰ and ~1‰ respectively. These enrichments can be attributed to either a ‘vital effect’ or a higher calcification rate. An interesting pattern of increase in the δ¹³C(DIC) value of the surface water with latitude is observed between 35°S and~ 60°S, with a peak at~ 42°S. This can be caused by increased organic matter production and associated removal. A simple model accounting for the increase in the δ¹³C(DIC) values is proposed which fits well with the observed chlorophyll abundance as a function of latitude.

An improved method of high-precision determination of Δ(17)O of CO2 by catalyzed exchange with O2 using hot platinum

RATIONALE

CO2 and O2 can exchange their oxygen isotopes rapidly in the presence of hot (~670 °C) platinum and this has led to a method for determining the δ(17)O value of a CO2 sample. We have improved the method to achieve a precision of 0.008 ‰ (1-σ standard deviation) in the determination of δ(17)O values. Such high precision is essential to identify the stratospheric component in tropospheric CO2 and use it for global carbon flux studies. The crucial issue in the accurate determination of the δ(17)O value is estimation of a correction factor, which depends on the amount ratio CO2/O2. An attempt was also made to investigate the mechanism of exchange with their controlling parameters.

METHODS

The oxygen isotopes of a CO2 sample gas are exchanged with those of an appropriate amount of tank O2 in the presence of hot platinum. The pre-exchange CO2 and O2 gas samples as well as the post-exchange O2 sample are analyzed by isotope ratio mass spectrometry. A mixing model was developed involving the δ(18)O value of the CO2 and δ(17)O and δ(18)O values of pre- and post-exchange O2 to obtain the δ(17)O value of the CO2 sample. A correction to the measured value was determined to obtain the actual value with high accuracy and precision.

RESULTS

To obtain a precision better than 0.01 ‰ requires the amount ratio CO2/O2 to be controlled to better than ~15 %. We also find that the oxygen isotopes are nearly homogeneously distributed between the O2 and the CO2 molecules. In addition, determination of the (16) O(13)C(18)O/(16)O(12)C(16)O isotopologue ratio in the CO2 shows that the abundance of (16)O(13)C(18)O is close to that expected for random partitioning of the isotopes among the CO2 isotopologues.

CONCLUSIONS

The isotopic scrambling between O2 and CO2 that occurs on hot platinum allows one to accurately determine the δ(17)O values of CO2 through isotopic analysis of O2.

Isotopic homogenization and scrambling associated with oxygen isotopic exchange on hot platinum: studies on gas pairs (O2, CO2) and (CO, CO2)

The catalytic exchange between O₂ and CO₂ on hot platinum leads to isotope scrambling in CO₂ and homogenization of the oxygen isotopes in the two phases even though they could be different in isotope ratios from each other before the exchange.

Effectiveness of an Educational Feedback Intervention on Drug Prescribing in Dental Practice

Background Irrational use of drugs as well as inappropriate and over drug prescribing leads to unnecessary expenditures and emergence of resistant bacterial strains. Feedback intervention on drug prescribing habits and face to face educational intervention of prescription audit would be effective in rationalizing prescribing practices. Objective To measure the impact of educational feedback intervention on the prescribing behavior of dental surgeons. Methods Prospective audit of twelve hundred outpatients prescriptions in dental OPD at BPKIHS of those dental surgeon who attended the educational intervention session was collected randomly by trained persons on customized data collection sheet before and after educational intervention. Results A total 1200 prescription were collected, 300 before and 300 after intervention period at the internal of one month, three months and six months. Majority of the prescriptions (39.33%) contained four drugs but after intervention, prescriptions contained mostly one drug, 73% in first month, 78.67% in third month and 65.34% in six month. Mean number of drugs per prescription after intervention were decreased. There was increased number of generic names of drugs after intervention. Amoxicillin, Metronidazole, Chlorhexidine, Povidone iodine gargle, Nimesulide, Ibuprofen, Ibuprofen + paracetamol, and Paracetamol were most commonly prescribed by dental prescribers before and after intervention. Selection of antimicrobial was done on empirical basis which was correct because Amoxicillin concentration reaches effectively in gingival crevicular fluid and Metronidazole covered effectively against anaerobic bacteria were found in orodental infection. The uses of topical anti-infective preparation as irrigants of choice that can kill majority of micro-organisms found is root canal and dental tubules and minimize systemic use of antimicrobials. Nimesulide prescribing needs to be rationalized. Conclusion Feedback educational intervention of prescription audit is effective to improve their prescribing behaviors and rationalize drug utilization pattern for the benefit of the patients. DOI: http://dx.doi.org/10.3126/kumj.v10i4.10991 Kathmandu Univ Med J 2012;10(4):30-35

Effect of Isotopic Exchange upon Symmetry Dependent Fractionation in the O + CO → CO2 Reaction

In a recent study, it was demonstrated that the mechanism associated with the O + CO reaction produces a large, mass independent isotopic fractionation in the product CO2. A kinetic treatment of the data demonstrated that isotopic exchange between the O atom, produced by O2 photolysis and CO, occurred prior to the O + CO recombination. It was concluded that the likely source of the mass independent fractionation was the O + CO recombination. The present paper includes a kinetic evaluation of the added role of O + O2, along with O + CO, isotopic exchange. The new determinations provide a better fit of the experimental data.

New Evidence for Symmetry Dependent Isotope Effects: O+CO Reaction

The isotopic fractionation associated with the O + CO reaction has been studied using oxygen atoms produced by room temperature O2 photolysis at two different wavelengths, 185 and 130 nm. A large mass-independent isotopic fractionation is observed in the product CO2, extending the range of this type of reaction beyond O + O2 and SF5 + SF5.

Kinetic evaluation of the data restricts the source of the mass-independent fractionation mechanism to the O + CO recombination step rather than O2 photolysis, secondary ozone formation, or O2 photodissociation. At least one, and most likely two other fractionation processes appear to occur in the experiments, and interpretation of the isotopic results is tentative at present. Based on the relevant reaction rates and the value for the reduced partition function for isotopic exchange between O and CO, it is suggested that this process may occur prior to the δ17O≅δ18O recombination process. Secondary CO2 photolysis may superimpose an additional fractionation. The experimental data are also examined in the context of a model based upon energy randomization rates versus the lifetime of the activated complex.

Prostaglandin E1-induced Catalepsy in the Rat: Role of Putative Neutrotransmitters

Prostaglandin E1 (PGE1) produced dose-related catalepsy in rats when administered intracerebroventricularly. PGE1 induced catalepsy was significantly inhibited after pretreatment with pharmacological agents known to attenuate central serotonergic and cholinergic activity. It was also inhibited by PGF2α and naloxone. On the contrary, treatments enhancing central dopaminergic activity also reduced the cataleptic effect of PGE1. The results suggest that PGE1 induces catalepsy in rats by modulating activity of central neurotransmitters.

Prostaglandin d2 induced potentiation of the anticonvulsant actions of phenobarbitone and phenytoin in rats. Role of serotonin

Prostaglandin D2 (PGD2) produced a dose-related potentiation of the anticonvulsant actions of sub-effective doses of phenobarbitone and phenytoin against maximal electroshock-induced seizures in rats. PDG2-induced potentiation of phenobarbitone and phenytoin was significantly attenuated following pretreatment with centrally administered 5,6-dihydroxytryptamine, a selective neurotoxin for serotonergic neurones, p-chlorophenylalanine, a specific inhibitor of serotonin biosynthesis, and methysergide, a serotonin receptor antagonist, indicating that the potentiation was serotonin-mediated.

Prostaglandins and central serotonergic activity in the rat

Pharmacological and biochemical studies indicate that prostaglandins (PGs) exert a modulatory influence on rat brain serotonergic activity. With several experimental approaches, it has been shown that PGEs and PGD2 facilitate central serotonergic activity in rats. On the contrary, PGF2α not only inhibits rat brain serotonergic activity but also antagonizes the facilitatory effect of the other PGs. The studies support the proposed neuromodulatory role for PGs in central synaptic transmission.

Naloxone blocks the beneficial effects of aqueous extract of Murraya koenigii (L.) Spreng leaves in models of pain

AIM

This study investigated the antinociceptive effects of aqueous extract of Murraya koenigii (AEMK) leaves (200, 400 and 800 mg/kg, orally) on animal models of acute and persistent pain and its modulation by naloxone.

MATERIALS AND METHODS

Antinociceptive effects were assessed using tail-flick, hot plate and formalin tests in mice. To differentiate between central and peripheral antinociceptive effect of AEMK, naloxone (2 mg/kg) was administered along with the 800 mg/kg dose of extract. Morphine was used as a standard drug.

RESULTS

AEMK and morphine significantly increased the tail-flick latency (tfl) and paw licking/jumping latency in tail-flick and hot plate tests, respectively, in comparison to control. Also, in both the tests AEMK and morphine significantly increased the AUC0-120 min. In formalin test, AEMK (400 mg/kg and 800 mg/kg) and morphine significantly reduced licking time in both early and late phases in comparison to control.

CONCLUSIONS

Thus, in all three pain models AEMK showed antinociceptive effect, which was blocked by naloxone suggesting the involvement of opioidergic central mechanism.

Tobacco and alcohol: the relation to pulmonary tuberculosis in household contacts

Tuberculosis is transmitted commonly by droplet nuclei and facilitated by weak immune system. Lowered immunity may be associated with cigarette smoking, tobacco chewing and alcohol consumption. The co-relationship between these all factors to TB should be explored. This study aims to detect the hidden household contacts (HC) cases early and to examine the relative contribution of tobacco and alcohol use to the risk of TB. Across-sectional study was in Dharan among HCs. From June 2009 to May 2010, 184 index cases with sputum smear positive for AFB and their 802 HCs were included. Three sputum specimens were collected from each HCs and examined microscopically for AFB detection. AFB were detected in sputum of 13 (1.6%) HCs. The association between habits (alcohol user and smoking) and TB was found except with chewing tobacco user (P > 0.05). The risk of contact TB was 4 and 8 times greater in smoker (OR = 3.94 95% CI = 1.26-12.26, P < 0.05) and alcoholic (OR = 8.23 95% CI = 2.71-24.98, P < 0.05) HCs respectively. This study has revealed smoking and alcohols as the risk factors for tuberculosis. Effective campaign to discourage use of alcohol and tobacco, and awareness programme about the mode of transmission of TB are needed in community.

Prevalence of tuberculosis in household contacts of sputum smears positive cases and associated demographic risk factors

Pulmonary tuberculosis (PTB) is transmitted by aerosolized droplets nuclei. Home is the vulnerable place for transmission of this disease to its contacts. Risk factors associated with this contact transmission may differ according to locality. This study aims to determine the prevalence of household contact (HC) PTB and examine the risk factors contributing to it. A cross-sectional study was conducted to determine the prevalence of HC TB among HCs aged > 5 years in Dharan. During the study period (June 2009 - May 2010), 184 index cases with sputum smear positive for AFB and their 802 HCs were included. Three sputum specimens were collected from each HCs and examined microscopically for AFB detection. The prevalence of HC TB was found to be 1.6%. The result was statistically associated (P < 0.05) with illiterate HCs (OR= 5.77, 95%CI =1.52-21.81), close proximity with ICs (OR=3.07, 95%CI = 1.02-9.25), primary relatives to ICs (OR= 4.85, 95%CI = 1.07-22.05) and slum dweller (OR = 4.56, 95%CI = 1.25-16.71). Similarly, AFB positivity was associated (P<0.05) with household crowding (OR = 7.46, 95%CI = 2.36-23.49), room size < or = 10 x 10 feet (OR=4.05, 95%CI = 1.23-13.25), firewood user while cooking (OR = 5.96, 95%CI = 1.92-18.45). The prevalence of HCs tuberculosis is found to be 1.6%. Poverty, illiteracy, overcrowding, close proximity, close relation with ICs, firewood while cooking, slum dweller, are major factors highlighted by this study as risk factors of contact TB. Our results recommend a much better contact tracing and treatment program.

Etiological agents of corneal ulcer: five years prospective study in eastern Nepal

To identify the most common isolates from the corneal ulcers with antimicrobial pattern of bacterial isolates. All patients with suspected corneal ulceration presenting to BP Koirala Institute of Health Sciences from Jan 2004 - Dec 2008 were evaluated. Corneal scraping was performed and processed for direct microscopy, bacteriological and fungal culture. Bacterial isolates were subjected to antimicrobial susceptibility testing. Of 351 specimens examined, growth of etiological agents were obtained in 278 (79.20%). Of these, 113 (40.65%) had pure fungal growth, 108 (38.85%) had pure bacterial growth and 57 (20.50%) had mixed fungal and bacterial infection. The commonest fungal pathogen was Aspergillus spp 50 (33.33%) followed by Fusarium spp 19 (12.66%). Staphylococcal aureus 57 (44.53%) was isolated as commonest bacterial agent. Coagulase Negative Staphylococci 20 (15.6%) was second in the list. Pseudomonas spp 12 (9.40%) was the most common gram negative bacilli isolated. Most of the bacterial isolates were sensitive to commonly used antibiotics. Corneal Ulcer is a common problem in eastern Nepal. Knowledge of both fungal and bacterial agents associated with this condition is of value for the prevention and management of corneal ulcers and their complications.

Measurement of the 17O-excess (Δ17O) of tropospheric ozone using a nitrite-coated filter

RATIONALE

The (17)O-excess (Δ(17)O) of tropospheric ozone (O(3)) serves as a useful marker in studies of atmospheric oxidation pathways; however, due to the complexity and expense of currently available analytical techniques, no systematic sampling campaign has yet been undertaken and natural variations in Δ(17)O(O(3)) are therefore not well constrained.

METHODS

The nitrite-coated filter method is a new technique for O(3) isotope analysis that employs the aqueous phase NO(2)(-) + O(3) → NO(3)(-) + O(2) reaction to obtain quantitative information on O(3) via the oxygen atom transfer to nitrate (NO(3)(-)). The triple-oxygen isotope analysis of the NO(3)(-) produced during this reaction, achieved in this study using the bacterial denitrifier method followed by isotope-ratio mass spectrometry (IRMS), directly yields the Δ(17)O value transferred from O(3). This isotope transfer process was investigated in a series of vacuum-line experiments, which were conducted by exposing coated filters to O(3) of various known Δ(17)O values and then determining the isotopic composition of the NO(3)(-) produced on the filter.

RESULTS

The isotope transfer experiments revealed a strong linear correlation between the Δ(17)O of the O(3) produced and that of the oxygen atom transferred to NO(3)(-), with a slope of 1.55 for samples with bulk Δ(17)O(O(3)) values in the atmospheric range (20-40‰). This finding is in agreement with theoretical postulates that place the (17) O-excess on only the terminal oxygen atoms of ozone. Ambient measurements yield average Δ(17)O(O(3))(bulk) values in agreement with previous studies (22.9 ± 1.9‰).

CONCLUSIONS

The nitrite-coated filter technique is a sufficiently robust, field-deployable method for the determination of the triple-oxygen isotopic composition of tropospheric O(3). Further ambient measurements will undoubtedly lead to an improved quantitative view of natural Δ(17)O(O(3)) variation and transfer in the atmosphere.

Tuberculin reactivity in bacille calmette-guerin vaccinated individuals with sputum positive pulmonary tuberculosis

The study was carried out to assess the value of tuberculin skin test for the diagnosis of Tuberculosis (TB) in BCG vaccinated individuals and to find out the sensitivity rate of tuberculin skin test (TST) in comparison to acid fast bacilli positive pulmonary TB. Similar population with high BCG vaccination coverage having both pulmonary TB patients (n=150) and apparently healthy individuals (n=150) in eastern Nepal were enrolled in this comparative study. Sputum from all the subjects was subjected to Z-N microscopy. TST was performed on these subjects by standard Mantoux method. Among the patients (mean age 36.18±14.15 yrs) and controls (mean age 35.61±13.44 yrs), 55.33 % and 47.33 % respectively have been found to be positive PPD reactors (>10mm) which is statistically not significant (P>0.05). About 23% of the patients & 27% of controls failed to react (anergic) to 5 TU PPD. PPD reactivity rate was high in the patients whose sputum smears were graded as 1+ in Z-N microscopy. The sensitivity of TST was highest for the induration of >5mm (77.3%). Specificity increased with increasing size of induration and was highest (73.3%) with induration of >15 mm. Tuberculin skin test is an all or none phenomenon. In Nepal, tuberculin test has a limited value in the diagnosis of pulmonary TB as both the apparently healthy individuals and patients with sputum smear positive pulmonary TB who had been immunized with BCG, showed almost similar rate of tuberculin reactivity. DOI: http://dx.doi.org/10.3126/jcmsn.v7i1.5970 JCMSN 2011; 7(1): 28-35

In vitro activity of cefoperazone-sulbactam combination against gram negative bacilli

Cefoperazone is a â-lactam antimicrobial and Sulbactam is an irreversible â-lactamase inhibitor. The objective of this study was to know the susceptibility pattern of gram negative bacilli (GNB) towards cefoperazone-sulbactum. All GNB isolated from different clinical samples during the period of May, 2010 to Aug, 2010 were tested for susceptibility to cefoperazone-sulbactum, meropenem, ceftazidime, cefotaxime, ceftriaxone, chloromphenicol, cotrimoxazole, ampicillin, amikacin, nalidixic acid, ciprofloxacin, carbenicillin and piperacillin using standard Kirby-Bauer disc diffusion antimicrobial susceptibility testing method. The susceptibilities were recorded according to CLSI guidelines. A total of 406 GNB were isolated (urine: 66.7%, pus: 19.2%, and blood: 7.9%). Escherichia coli (54.4%) was most frequently isolated organisms followed by Acinetobacter species (17.7%), Klebsiella pneumoniae (9.1%) and Pseudomonas species (6.1%). Overall, 11.8% of isolates showed resistance to cefoperazone-sulbactam. Frequencies of isolates showing resistance to meropenem and amikacin were 14.7% and 26.25% respectively. Only 3.9% of Escherichia coli isolates showed resistance to cefoperazone-sulbactam. For other organisms, their lowest frequency ranging from 0-20%, exhibited resistance to meropenem. In Pseudomonas spp, in-vitro activity of amikacin was also better as only 11.1% isolates showed resistance to it. This study demonstrated the in-vitro synergistic effect of cefoperazonerazone-sulbactam and meropenem having good activity against GNB compared to the activity of other commonly tested antimicrobials. Cefoperazone-sulbactam can be recommended for the clinical practice against GNB exhibiting resistant to other antimicrobials as it is cheaper alternative to meropenem. Our results also focused on the continuous surveillance of the trends and features of resistance of common antimicrobials.

Signet ring cell carcinoma of the gallbladder: a case report

Carcinoma of the gall bladder is the most common biliary tract tumor with higher incidence in females and increasing age. The risk is significantly higher in cholelithiasis. Signet ring cell carcinoma is a rare form of mucinous adenocarcinoma and has a worse prognosis. Early diagnosis is rare. We report a case of signet ring cell carcinoma of the gall bladder in a 70 years old female patient. The gross finding was yellowish white mass measuring 4 x 3.5 cm on cut surface of the gall bladder along with thickened wall. Histopathological examination of the specimen shows the sheets of signet ring cells with lateral spread through the lamina propria and large amount of extracellular mucin. There was metastasis in the retroperitoneum and mesenteric lymph node. The tumor was stage IV (according to TNM staging). Patient died 20th post operative day. Since very few cases have been reported, information regarding the behavior and prognosis of gall bladder carcinoma is limited. However it has been seen that stage III and IV carcinoma usually have worse prognosis.

Study of patients with painless inguinal hernia in the quality of life

Inguinal hernias are one of the commonest surgical problems in our set up. It is a protrusion of abdominal cavity contents through the inguinal canal. This is a retrospective study done in the Department of Surgery, Nepal Medical College Teaching Hospital (NMCTH) from January 2009 to December 2010. During this period, 120 patients with painless hernia were enrolled in the study. The age range was from 30 years to 76 years with mean age of presentation at 53 years. Out of 120 patients who underwent mesh repair only 74 patients (61.7%) had visible hernia on standing and 46 patients (38.3%) had palpable impulse on cough. 90 patients (75%) were males and indirect hernia (53.3%) was more common than direct hernia. Out of 120 cases, 30 cases underwent inguinal neurectomy which on follow up had no pain at all. In other 90 cases, neurectomy was not confirmed from the operative note. In these 90 cases, 12 patients had mild pain and 10 patients had moderate to severe pain on 6 months follow up. To conclude, surgical repair is recommended for painless inguinal hernia as most of the patients develop symptoms over time and to avoid undue complications.

Effect of Ocimum sanctum, ascorbic acid, and verapamil on macrophage function and oxidative stress in mice exposed to cocaine

OBJECTIVE

To investigate the effect of Ocimum sanctum, ascorbic acid, and verapamil on macrophage function and oxidative stress in experimental animals exposed to cocaine.

MATERIALS AND METHODS

Mice were used in this study and were divided randomly into different groups of six animals each. They were either treated with intraperitoneal injection of saline or cocaine hydrochloride or an oral feeding of oil of Ocimum sanctum, ascorbic acid or verapamil, or both (ascorbic acid and verapamil), and were evaluated for a respiratory burst of macrophages, superoxide and nitric oxide (NO) production, estimation of TNF-alpha in the serum and supernatant of cultured macrophages, estimation of lipid peroxidation (malondialdehyde- MDA) in the serum, and superoxide dismutase activity in the erythrocytes.

RESULTS

Unstimulated respiratory burst as well as superoxide production was enhanced on treatment with cocaine and all the three drugs were found to attenuate this enhancement. The bactericidal capacity of macrophages decreased significantly on chronic cocaine exposure, as it was associated with decreased respiratory burst and superoxide production. There was a significant decrease in NO production by macrophages on chronic cocaine exposure and all the test drugs were found to restore nitrite formation to a normal level. There was an increase in the malonylodialdehyde (MDA) level and decrease in the superoxide dismutase level on chronic cocaine exposure, and all the three drugs effectively decreased the MDA level and increased superoxide dismutase level. There was an increase in serum TNF-alpha on chronic cocaine exposure, which was decreased significantly by ascorbic acid and verapamil.

CONCLUSION

O. sanctum, ascorbic acid, and verapamil were equally effective in improving the macrophage function and reducing oxidative stress. These findings suggested that O. sanctum, ascorbic acid, and verapamil attenuated acute and chronic cocaine-mediated effects.

Comparison of antinociceptive effect of the antiepileptic drug gabapentin to that of various dosage combinations of gabapentin with lamotrigine and topiramate in mice and rats

INTRODUCTION

Newer anticonvulsants have a neuromodulatory effect on pain perception mechanisms in a hyperexcitable and damaged nervous system.

AIM

This study was designed to study the analgesic effects of gabapentin alone and in combination with lamotrigine and topiramate in experimental pain models.

MATERIALS AND METHODS

Adult albino mice (n=490) weighing 20-30 g and rats (n=130) weighing 100-200 g were injected intraperitoneally with gabapentin, lamotrigine, and topiramate alone and in different dose combinations. The hot-plate method, tail-flick method, capsaicin-induced mechanical hyperalgesia, and formalin assay were used to assess the antinociceptive effects.

RESULTS

Of the three antiepileptic drugs, when given separately, gabapentin was more efficacious than either topiramate or lamotrigine in all the pain models. Combination of 25 mg/kg gabapentin with 25 mg/kg topiramate was more efficacious (P<.05) than 50 mg/kg gabapentin alone in the capsaicin-induced mechanical hyperalgesia test. Similarly, 50 mg/kg gabapentin with 50 mg/kg topiramate or 5 mg/kg lamotrigine was more efficacious (P<.05) than 50 or 100 mg/kg gabapentin alone in late-phase formalin-induced behaviors.

CONCLUSIONS

Combination of gabapentin with either lamotrigine or topiramate produced better results than gabapentin alone in capsaicin-induced mechanical hyperalgesia test and in late-phase formalin-induced behaviors.

Antimicrobial Resistant Streptococcus pneumoniae

Introduction: Pneumococcal infections are important cause of morbidity and mortality. Knowledge of antimicrobial susceptibility patterns plays important role in the selection of appropriate therapy.  Present study was undertaken to analyze the susceptibility patterns of pneumococcal isolates against  commonly used antimicrobials with special reference to determination of minimum inhibitory  concentration (MIC) of penicillin in a tertiary care hospital in eastern Nepal. Methods: Twenty-six strains of S. pneumoniae isolated from various clinical specimens submitted to microbiology laboratory were evaluated. All isolates were tested for antimicrobial susceptibility by  disk diffusion method. MIC of penicillin was tested by broth dilution method. Results: Of the total isolates 19 (73%) were from invasive infections. Seven isolates were resistant to cotrimoxazole. No resistance to penicillin was seen in disk diffusion testing. Less susceptibility to penicillin (MIC 0.1-1.0 mg/L) was observed in five (17%) isolates. High level resistance to penicillin was not detected. One isolate was multidrug resistant. Conclusions: S. pneumoniaeisolates with intermediate resistance to penicillin prevail in Tertiary Care Hospital in eastern Nepal, causing invasive and noninvasive infections. As intermediate resistance is not detected in routine susceptibility testing, determination of MIC is important. It helps not only in the effective management of life threatening infections but is also essential in continuous monitoring and early detection of resistance. In addition, further study on pneumococcal infections, its antimicrobial resistance profile and correlation with clinical and epidemiological features including serotypes and group prevalence is recommended in future. Keywords: antimicrobial susceptibility pattern, penicillin, Streptococcus pneumoniae.

Elimination of neglected tropical diseases in the South-East Asia Region of the World Health Organization

The neglected tropical diseases (NTDs), which affect the very poor, pose a major public health problem in the South-East Asia Region of the World Health Organization (WHO). Although more than a dozen NTDs affect the region, over the past five years four of them in particular - leprosy, lymphatic filariasis, visceral leishmaniasis (kala-azar) and yaws - have been targeted for elimination. These four were selected for a number of reasons. First, they affect the WHO South-East Asia Region disproportionately. For example, every year around 67% of all new leprosy cases and 60% of all new cases of visceral leishmaniasis worldwide occur in countries of the region, where as many as 850 million inhabitants are at risk of contracting lymphatic filariasis. In addition, several epidemiological, technological and historical factors that are unique to the region make each of these four diseases amenable to elimination. Safe and effective tools and interventions to achieve these targets are available and concerted efforts to scale them up, singly or in an integrated manner, are likely to lead to success. The World Health Assembly and the WHO Regional Committee, through a series of resolutions, have already expressed regional and global commitments for the elimination of these diseases as public health problems. Such action is expected to have a quick and dramatic impact on poverty reduction and to contribute to the achievement of the Millennium Development Goals. This paper reviews the policy rationale for disease control in the WHO South-East Asia Region, the progress made so far, the lessons learnt along the way, and the remaining challenges and opportunities.

Antimicrobial resistant Streptococcus pneumoniae

INTRODUCTION

Pneumococcal infections are important cause of morbidity and mortality. Knowledge of antimicrobial susceptibility patterns plays important role in the selection of appropriate therapy. Present study was undertaken to analyze the susceptibility patterns of pneumococcal isolates against commonly used antimicrobials with special reference to determination of minimum inhibitory concentration (MIC) of penicillin in a tertiary care hospital in eastern Nepal.

METHODS

Twenty-six strains of S. pneumoniae isolated from various clinical specimens submitted to microbiology laboratory were evaluated. All isolates were tested for antimicrobial susceptibility by disk diffusion method. MIC of penicillin was tested by broth dilution method.

RESULTS

Of the total isolates 19 (73%) were from invasive infections. Seven isolates were resistant to cotrimoxazole. No resistance to penicillin was seen in disk diffusion testing. Less susceptibility to penicillin (MIC 0.1-1.0 mg/L) was observed in five (17%) isolates. High level resistance to penicillin was not detected. One isolate was multidrug resistant.

CONCLUSIONS

S. pneumoniae isolates with intermediate resistance to penicillin prevail in Tertiary Care Hospital in eastern Nepal, causing invasive and noninvasive infections. As intermediate resistance is not detected in routine susceptibility testing, determination of MIC is important. It helps not only in the effective management of life threatening infections but is also essential in continuous monitoring and early detection of resistance. In addition, further study on pneumococcal infections, its antimicrobial resistance profile and correlation with clinical and epidemiological features including serotypes and group prevalence is recommended in future.

Ayurvedic processed seeds of nux-vomica: neuropharmacological and chemical evaluation

The effect of detoxification on Strychnos nux-vomica seeds by traditional processing with aloe and ginger juices (B), by frying in cow ghee (C), and by boiling in cow milk (D) was investigated. The ethanolic extracts of these samples were subjected to spontaneous motor activity (SMA), pentobarbitone-induced hypnosis, PTZ induced convulsions, diazepam-assisted protection, and morphine-induced catalepsy. All samples reduced SMA and inhibited catalepsy. The seeds processed in milk (D) showed the lowest strychnine content in the cotyledons, exhibited marked inhibition of PTZ induced convulsions and maximal potentiation of hypnosis, and were the safest (LD(50)).

Phenotypic characterisation and drug sensitivity testing of mycobacteria isolated from extra-pulmonary tuberculosis

BACKGROUND

Tuberculosis (TB) is a major cause of morbidity and mortality globally, with most cases occurring in developing countries. The importance of extra pulmonary tuberculosis (EPTB) among all forms of tuberculosis has not yet been ascertained in developing countries.

OBJECTIVE

To identify and perform phenotypic characterization of clinically important mycobacterium isolates from extra-pulmonary sites along with drug susceptibility testing.

MATERIALS AND METHODS

A total of 513 specimens from patients of (EPTB) with varied presentation were studied. Speciation and characterization of isolates were done on the basis of growth and biochemical characteristics. Drug susceptibility testing for mycobacterium isolates was done by proportion method.

RESULTS

Fifty four patients clinically suspected to have extra-pulmonary tuberculosis were culture positive for mycobacteria. On characterization 48 of the 54 isolates were identified as M. tuberculosis, 4 as M. bovis and 2 were M. avium/intracelulare. Drug susceptibility testing was done for the both M. tuberculosis as well as M. bovis. In single drug resistance, Streptomycin was highest followed by Isoniazid, Ethambutol and Refampicin. Multi drug resistance (MDR) was found in 6 isolates and it was observed only in group I cases.

CONCLUSION

EPTB accounts for 10-15 percent of all cases of tuberculosis. Mycobacterium was present in 10.5 percent samples. 48 isolates out of 54 samples were found to be M. tuberculosis. The maximum numbers of M. tuberculosis were isolated from lymph node aspiration.

Vaccine desirability during an effectiveness trial of the typhoid fever polysaccharide Vi vaccine in Kolkata India

BACKGROUND

High rates of typhoid fever and the emergence of multi-drug resistant strains create a need for prevention efforts including vaccines. Socio-behavioral research can provide important data for participation in future trials and public health vaccination campaigns.

DESIGN

A 3b phase clinical trial in Kolkata India including pre- and post-vaccination socio-behavioral surveys.

RESULTS

47.9% of respondents were male. Ward 29 respondents included 32.4% Hindu and Ward 30 respondents were 99.0% Hindu. Lower rates of participation were found among Muslim respondents and those with post high school education. Lack of information and negative information affected participation. Joint decision-making within households increased participation rates.

METHODS

seven hundred households were randomly selected 503 respondents (71.85%) completed both the pre- and post-closed-ended surveys. Data analysis included descriptive statistics, Pearson's chi-square tests, independent t-tests, and stepwise logistic regression analysis. Four open-ended questions were included in the survey. These qualitative data were coded and reviewed for common themes and patterns.

CONCLUSIONS

Individuals' decisions to participate or not participate in a vaccine trial entail a balance between individual beliefs, household dynamics and socio-political influences. Efforts prior to vaccination trials need to develop strategies which address potential underlying mediators for belief systems as well as structural factors which may reinforce individuals' beliefs and perceptions about vaccination trials.

Anomalous enrichment of 17O and 13C in photodissociation products of CO2: possible role of nuclear spin

Oxygen and carbon isotope fractionation associated with products (CO and O(2)) of gas phase photodissociation of CO(2) have been studied using photons from Hg lamp (184.9 nm) and Kr lamp (123.6 and 116.5 nm). In dissociation by Hg lamp photons both CO and O(2) are enriched in (17)O by about 81 per thousand compared to the estimate based on a kinetic model. Additionally, CO is enriched in (13)C by about 37 per thousand relative to the model composition. In contrast, in dissociation by higher energy Kr lamp photons no such anomaly was found in O(2). The observed isotopic enrichments in case of Hg lamp dissociation are proposed to be due to a hyperfine interaction between nuclear spin and electron spins or orbital motion causing enhanced dissociation of isotopologues of CO(2) containing (17)O and (13)C. The (17)O enrichment is higher than that of (13)C by a factor of 2.2+/-0.2 which can be explained by the known magnetic moment ratio of (17)O and (13)C due to differing nuclear spins and g-factors. These results have potential implications in studies of the planetary atmospheres.

Epidemiological and bacteriological profile of burn patients at Nepal Medical College Teaching Hospital

This study was conducted to know the epidemiological and bacteriological profile of burn patients at Nepal Medical College Teaching Hospital. The charts of 50 burn patients admitted in department of surgery were reviewed retrospectively. All the epidemiological characteristics, mode of injury, time taken to reach hospital and involved body surface areas were noted. The charts were also reviewed for bacterial isolates from burn wounds and its sensitivity pattern for various antibiotics. Data was analyzed using the statistical package for social sciences (SPSS) for Windows. The mean age of patients was 31.8 years with male:female ratio of 1.3:1. Half of the patients were from Kathmandu. Fifty two percent of patients directly came to our hospital while rests were referred from other hospitals. The average time taken to reach hospital was 11.3 hours. Those patients who were referred from outside the valley took longer time (p = 0.002). Flame burn was the leading cause for injury (66.0%) followed by scald burn (16.0%), electric burn (14.0%) and acid burn (4.0%). Staphylococcus aureus (28.0%) was the commonest organism isolated from wound swab culture. Others were Klebsiella (16.0%), Pseudomonas (13.0%), Proteus (13.0%) and E.coli (13.0%). No growth was noted in 17.0% of patients. During the treatment, 14.0% of patients died and 4.0% left against medical advice. Remaining patients were discharged after complete recovery. Body surface area involvement was found to be a significant predictor of mortality (p < 0.001) and the length of hospital stay was significantly low for them (p = 0.05).

Prescription Writing Skills of Pre-Clinical Medical and Dental Undergraduate Students

Objective of this prospective study was to assess the acquisition of prescribing skill of preclinicalmedical and dental undergraduate students. Prescription writing skills of 258 students of both firstand second year of MBBS and BDS students were analyzed through an objective structured practicalexamination. MBBS student of second year scored 85.01% and 92.82% respectively in physician anddrug related component whereas first year MBBS students scored 89.9% and 83.4%. BDS studentof first year scored 91.96% and 86.33% in physician and drug related components which is betterthan second year that scored 83.33% and 77.94% respectively. This study revealed that the studentsof both courses acquire prescribing skills to a limited extent during preclinical phase. Prescribingerrors were found both in physician and drug related components. To minimize the different form ofprescribing errors vigorous training in the internship period will help to minimize prescribing errorsand improve rational prescribing too.Key words: dental, examination, medical, objective, prescription, student

Prescription writing skills of pre-clinical medical and dental undergraduate students

Objective of this prospective study was to assess the acquisition of prescribing skill of preclinical medical and dental undergraduate students. Prescription writing skills of 258 students of both first and second year of MBBS and BDS students were analyzed through an objective structured practical examination. MBBS student of second year scored 85.01% and 92.82% respectively in physician and drug related component whereas first year MBBS students scored 89.9% and 83.4%. BDS student of first year scored 91.96% and 86.33% in physician and drug related components which is better than second year that scored 83.33% and 77.94% respectively. This study revealed that the students of both courses acquire prescribing skills to a limited extent during preclinical phase. Prescribing errors were found both in physician and drug related components. To minimize the different form of prescribing errors vigorous training in the internship period will help to minimize prescribing errors and improve rational prescribing too.