Antibacterial photodynamic therapy on Staphylococcus aureus and Pseudomonas aeruginosa in-vitro

Photodynamic therapy (PDT) involves the use of drugs or dyes known as photosensitizers, and light source which induces cell death by the production of cytotoxic reactive oxygen species (ROS). This principle of cell death can be utilized to kill bacteria in vitro. We propose the use of blue light emitting diodes (LEDs) and Riboflavin as the light source and photosensitizer for in vitro killing of Staphylococcus aureus and Pseudomonas aeruginosa. Circularly arranged 65-blue LED array was designed as the light source to fit exactly over 7cm culture plate. Riboflavin having non-toxic properties and nucleic acid specificity was used as a photosensitizer. Clinical isolates of Staphylococcus aureus and Pseudomonas aeruginosa were used in our study. Effect of PDT on viability on these species of bacteria was compared with control samples that included: control untreated, control treated with light only and control treated with riboflavin only. Statistical analysis was done using one-way ANOVA test. PDT against Pseudomonas aeruginosa and Staphylococcus aureus was significantly (p < 0.05) effective compared to all control samples. Combination of blue LEDs and Riboflavin in PDT against these bacterial species has been successfully demonstrated in-vitro. Therefore, PDT has promising applications in the process of treating superficial wound infections.

Changing trends of services used as first contact by patients with mental health problems

BACKGROUND

In the past, traditional faith healers and practitioners of alternative medicine have often been reported to be the first source of contact for Indian patients with mental health problems. However, over the past few decades, this trend seems to be changing.

METHOD

Using a semi-structured questionnaire, we assessed 200 new patients at a psychiatric outpatient service in a general hospital for the first service contact used by them for their mental health problems.

RESULTS

Psychiatrists, non-psychiatric physicians, traditional faith healers and practitioners of alternative medicine were the first service contact for 91 (45.5%), 88 (44%), 16 (8%) and 5 (2.5%) patients, respectively. Patients suffering from severe mental illnesses were more likely to choose a psychiatrist as the first contact, whereas those with neurotic, stress-related and organic mental disorders contacted a non-psychiatric physician.

CONCLUSION

In the current scenario, psychiatrists and nonpsychiatric physicians serve as the first service contact for most patients with mental health problems in India, though traditional faith healers and practitioners of alternative medicine are contacted by a minority.

Cytotoxic and genotoxic effects of mercury in house fly Musca domestica (Diptera: Muscidae)

Mercury, one of the most widely diffused and hazardous environmental contaminants, induces oxidative stress in organisms, which ultimately leads to genotoxicity and cytotoxicity. House fly Musca domestica L. was used as a model for assaying the genotoxic potential of mercury with the help of micronucleus assay, chromosomal aberration assay as end points and cytotoxicity by assaying the mitotic index and the extent of tissue damage by trypan blue dye exclusion. Late third instar larvae were exposed to different dietary concentrations of mercury (0.0001 mg/ml- 10 mg/ml) for various time intervals. A dose dependent increase in chromosomal aberrations, micronucleus frequency and mitotic index was observed. Micronucleus frequency increases with time while mitotic index decreases showing decreasing rate of cell proliferation due to an increase in cell death. Trypan blue staining gives the visual manifestation of cytotoxicity at higher concentrations of mercury (1 mg/ml- 10mg/ml). The present study suggests that the house fly model may be used to assay the genotoxicity and cytotoxicity of mercury as well as other environmental pollutants.

Small interfering RNAs targeting viral structural envelope protein genes and the 5ʹ-UTR inhibit replication of bovine viral diarrhea virus in MDBK cells

Bovine viral diarrhea viruses (BVDVs) are important pathogens of cattle that occur worldwide, and for which no antiviral therapy is available. In the present study, the inhibitory effect of small interfering (si) RNAs on bovine viral diarrhea virus 1 (BVDV-1) replication in cultured bovine cells was explored. Four synthetic siRNAs were designed to target structural envelope region genes (Erns, E1, and E2) and one cocktail of siRNA was generated to target the 5ʹ-UTR of the BVDV-1 genome. The inhibitory effects of siRNAs were assessed by determination of infectious viral titer, viral antigen and viral RNA. The siRNA cocktail and three of the synthetic siRNAs produced moderate anti-BVDV-1 effect in vitro as shown by 25%-40% reduction in BVDV-1 antigen production, 7.9-19.9-fold reduction in viral titer and 21-48-fold reduction in BVDV-1 RNA copy number. Our findings suggest that siRNA cocktail targeted at the 5ʹ-UTR is a stronger inhibitor of BVDV-1 replication and the targets for siRNA inhibition can be extended to BVDV-1 structural envelope protein genes.

GenMed 010: a one day workshop on generic medicines

This report outlines the content of a one-day workshop on Generic Medicines that was held at KIST Medical College, Lalitpur, Nepal on 13(th) December 2010, which was attended by 32 delegates from different institutions in Nepal, including pharmacists, pharmacologists and medical doctors. Right medicine, right patient, right dose, right frequency and duration, right information and right monitoring are conditions to be fulfilled for the rational use of medicine (RUM). The World Health Organization (WHO) defines generic medicine as 'a pharmaceutical product, usually intended to be interchangeable with the innovator product, marketed after the expiry of patent or other exclusivity rights'. Economic factors, supportive legislation and regulation, public and professional acceptance and quality assurance are key enabling factors promoting use of generics. Increased patent protection for medicines and removing process patents is a key feature of new trade agreements and newer medicines for diseases like HIV/AIDS, tuberculosis and infectious diseases are likely to be more expensive. The Medicine and Therapeutics Committee (MTC) can play a key role in promoting generic medicine use in institutions.Nepal being among the Least Developed Countries (LDCs) need not provide patent protection for medicines until 31(st) December 2015. Only a few 'true' generics are available in Nepal and there is huge cost variation in the price of different branded generics. Clinicians have concerns about the quality of medicines in general, substitution of poor quality brands by pharmacists and about therapeutic substitution. Generics have to meet the same regulatory requirements and be bioequivalent to reference preparations assuring their quality.

Effect of surfactants on phosphatase level of fresh water fish Labeo rohita

Alterations in the activity of enzymes Acid phosphatase (E.C.3.1.3.2) and Alkaline phosphatase (EC 3.1.3.1) in organs such as liver, gills and muscle of rohu following its exposure to surfactants viz. CTAB, SDS and Triton X-100 were analyzed. Different levels of exposure were given depending on the LC50 value of the surfactant used. Also, the influence of age and weight of the organisms was tested simultaneously. The activity of ACP in the tissues of fish exposed to all the three surfactants showed marked enhancement after exposure; the effect being highest in the liver followed by gill and muscle. Activity levels of ALP in different tissues of the fish exposed to the surfactants also showed an increase. Maximum increase was found in the liver followed by muscle, and gill. The increase in the levels of these enzymes indicates a stressful condition of the fish.

Combined effects of arginine and hydroxyurea on BFU-E derived colony growth and HbF synthesis in erythroid progenitors isolated from sickle cell blood

Hydroxyurea (HU) increases HbF synthesis in sickle cell disease (SCD). Recent studies suggest HU-induced HbF synthesis is mediated through a NO-cGMP pathway. Since arginine is the main precursor of NO, we investigated the effects of arginine and HU mixtures on HbF synthesis and burst forming unit erythroid (BFU-E) proliferation. Mixtures of HU (0, 15, 25, 100μM) and arginine (0, 25, 50, and 100μM) resulting in optimal HbF synthesis and minimal HU-induced cytotoxicity in erythroid progenitors were determined. HU dose-dependently attenuated growth of BFU-E colonies and stimulated HbF synthesis. In contrast, arginine dose-dependently increased BFU-E colonies without affecting HbF synthesis. Furthermore, arginine at concentrations >100μM in combination with varying concentrations of HU, decreased HbF synthesis compared to HU controls. HU, 15-25μM, in combination with 25-50μM arginine not only minimized cytotoxicity, but also increased HbF synthesis when compared with HU controls. NG-nitro-L-arginine-methyl ester (L-NAME; 100μM), a nitric oxide synthase inhibitor, attenuated the effects of HU+arginine on HbF synthesis compared to HU and HU+arginine controls. These results suggest HU+arginine-induced HbF synthesis in human erythroid progenitors is NO dependent. The synergistic effect on HbF synthesis seen with combinations HU+arginine is an important observation in understanding potential therapeutic uses of HU and arginine.

Childhood neurological illness in Nepal

The commonly encountered neurological disorders in Nepalese children are febrile encephalopathies, neurocysticercosis, and epilepsy, and neonatal encephalopathy, neuro-psychiatric and neuromuscular disease. Also, these children in Nepal remain one of the most vulnerable and marginalized groups in the community. Due to the lack of proper facilities some preventable and treatable neurological conditions continue to paralyze the children's physical and mental health. The alarmingly high prevalence of these neurological illnesses has high mortality and morbidity in children ultimately adding financial burden to the family, society and the country as a whole. The paucity of data and difficulties in proper collection of reliable facts further hampers to understand the actual magnitude of this problem.

Molecular characterization of RNA and protein synthesis during a one-step growth curve of bovine viral diarrhoea virus in ovine (SFT-R) cells

The aim of this study was to determine the kinetics of noncytopathic bovine viral diarrhoea virus (BVDV) multiplication and synthesis of BVDV specific RNA and proteins in ovine cells (SFT-R) during a one-step growth curve. The virus titre and RNA level were determined by focus-forming assay and real time RT-PCR. The RNA synthesis was detected by Northern blot while synthesis of E2 and NS3 proteins was assayed by immunohistochemistry and Western blot. The results showed that synthesis of viral RNA is initiated at 4h, NS3 and E2 proteins are detectable at 6-7h and the replication cycle is complete at 10-12h. Additionally, we provide evidence that NS2-3 protein was cleaved in ovine cells early during infection and in proliferated leukocytes of acutely infected sheep. This study showed that synthesis of BVDV RNA and proteins in ovine cells occurs at similar times as found in bovine cells.

Why is it important to study malaria epidemiology in India?

Malaria is a major vector-borne disease in India. Based on vast geographic areas with associated topographic and climatic diversity, the variable malaria epidemiology in India is associated with high parasite genetic diversity and rapidly evolving drug resistance, differential distribution of vector species and emerging insecticide resistance and underlying human genetic diversity and past evolutionary histories. Further, changing climatic patterns have possibly changed malaria epidemiology to a great extent. The outcome of these changes is an increased incidence of Plasmodium falciparum over the P. vivax malaria in recent years. Accordingly, the drug and insecticide application policy in India has changed too. The above facts and associated rapid shifting trend of malaria epidemiology makes India a hot-spot for malaria research.

Identification of bovine viral diarrhea virus type 1 in yaks (Bos poephagus grunniens) in the Himalayan region

Since cattle are widely infected by bovine viral diarrhea virus (BVDV) in India, we searched for pestivirus infection in yaks. Of 71 pure and crossbred yaks from Himalayan region, pestivirus antigen was detected by Ag-ELISA in three animals. Pestivirus in leukocyte and cell culture isolated virus samples originating from positive yaks was also confirmed by RT-PCR using panpestivirus specific primers selected from 5'-untranslated region (5' UTR). The 5' UTR, N(pro) and E2 regions were sequenced and used for genetic typing. Phylogenetic analysis revealed that pestiviruses detected in three Himalayan yaks were similar genetically, belonging to BVDV-1. Antigenic characterisation of yak pestivirus also confirmed the typing as BVDV-1. This is the first report on the identification of BVDV type 1 in yaks.

Membrane fluidity and lipid composition in clinical isolates of Candida albicans isolated from AIDS/HIV patients

In this study, we describe the membrane lipid composition of eight clinical isolates (azole resistant and sensitive strains) of Candida albicans isolated from AIDS/ HIV patients. Interestingly, fluorescence polarization measurements of the clinical isolates displayed enhanced membrane fluidity in fluconazole resistant strains as compared to the sensitive ones. The increase in fluidity was reflected in the change of membrane order, which was considerably decreased (decrease in fluorescence polarization "p" value denotes higher membrane fluidity) in the resistant strains. The ergosterol content in azole susceptible isolates was greater, almost twice as compared to the resistant isolates. However, no significant alteration was observed in phospholipid and fatty acid composition of these isolates. Labeling experiments with fluorescamine dye revealed that the percentage of phosphatidylethanolamine exposed to the membrane's outer leaflet was higher in the resistant strains as compared to the sensitive strains, indicating increased floppase activity of the two major ABC drug efflux pumps, CDR1 and CDR2 possibly due to their overexpression in resistant strains. The results of the present study suggest that changes in the status of membrane lipid phase especially the ergosterol content and increased activity of drug efflux pumps by overexpression ofABC transporters, CDR1 and CDR2 might contribute to fluconazole resistance in C. albicans isolated from AIDS/HIV patients.

Genetic and antigenic characterization of bovine viral diarrhea virus type 2 isolated from Indian goats (Capra hircus)

Recent studies have shown that bovine viral diarrhea virus (BVDV) type 1 is widely prevalent in Indian cattle. In a surveillance of randomly collected 562 blood samples from seven states during 2004-2006, BVDV type 2 was detected in two native Indian goats by nested reverse transcription polymerase chain reaction (nRT-PCR). The virus isolated from them was classified antigenically as BVDV 2 on the basis of virus neutralization test and reactivity with monoclonal antibodies. Phylogenetic analysis of three different genomic regions, 5' un-translated region (5' UTR), E(rns) structural coding region and NS5B nonstructural coding region typed Indian goat isolate as BVDV 2a having close similarity with strains from North America and Europe suggesting its probable introduction through trade. It was placed in a separate clade within the 2a branch having unique mutations in E(rns) and NS5B region. This is the first report of BVDV 2 in India and only second time recorded in goat species. The isolation of BVDV 2 from goat warrants intensive surveillance in cattle and sheep.

Pathogenicity of an Indian isolate of bovine viral diarrhea virus 1b in experimentally infected calves

The aim of this study was to determine the pathogenicity of an Indian bovine viral diarrhea virus (BVDV) 1b isolate in 7-9-months-old male calves. Infected (four) and control (two) calves were bled at three days interval for hematological, virological and serological studies until day 27. All infected calves developed respiratory illness, biphasic pyrexia, mild diarrhea, leucopenia and mild thrombocytopenia. Viraemia was demonstrated between 3 and 15dpi and the infected calves seroconverted by 15dpi. Prominent kidney lesions were endothelial cell swelling, proliferation of mesangial cells and podocytes leading to glomerular space obliteration. Degeneration and desquamation of cells lining seminiferous tubules were observed in two infected calves. Consolidation of lungs with interstitial pneumonia, mild gastroenteritis and systemic spread were also evident. It was concluded that Indian BVDV isolate induced moderate clinical disease in calves and glomerulonephritis resulting from acute BVDV infection was observed for the first time.