Systemic Therapy of Dermtophytosis with Voriconaole: A Clinical Observational Study of 250 Bangladeshi Patients.

Superficial fungal infection or dermatophytosis is one of the most common dermatological problems in a tropical country like Bangladesh. For last 4-5 years this skin problem is on rise with increase in cases of recalcitrant, recurrent and chronic dermatophytosis. In place of an easy task to treat dermatophytosis recently it has evolved into difficult to treat by traditional antifungal agents. Meanwhile, voriconazole, primarily appeared as an agent for deep fungal infections, has come out as a new promising systemic antifungal drug for dermatophytosis also. In Bangladesh recently an endeavor has been made to treat superficial fungal infection with voriconazole. Two hundred and ninety four patients suffering from recalcitrant, recurrent, resistant and chronic dermatophytosis between 12 and 70 years of age and both sexes were selected for the study between August 2018 and November 2018 from different parts of the country. Two categories of therapy were designed: Group A - 200mg 12 hourly for 14 days and Group B - 200mg 12 hourly for 28 days. Patients showing full response in 2 weeks were declared apparently cured and were kept under follow up. Those who did not show significant response (less than 50% improvement) in 2 weeks were considered failed. Unresponsive cases after 28 days were considered failed. Both groups were followed up for 4 weeks. Cases not showing any activity of the disease and negative microscopy on two occasions at 2 weeks interval were considered cured. Two hundred and fifty patients completed the study. Incidence of cure rate was more in Group B (93.04%) which is statistically significant (p<0.005). Relapse rate was observed more in Group A (22.83%). Visual side effects were 4.4% while vertigo and headache were observed in 12.0% and 10.8% respectably. Voriconazole is a promising treatment option for recurrent, recalcitrant and chronic dermatophytosis in dosage of 200mg twice daily for at least 4 weeks with negligible side effects. More diversified studies with longer follow up period is required for further opinion to establish an authenticated dosage schedule for treatment of superficial fungal infection.

Global maps of travel time to healthcare facilities.

Access to healthcare is a requirement for human well-being that is constrained, in part, by the allocation of healthcare resources relative to the geographically dispersed human population1-3. Quantifying access to care globally is challenging due to the absence of a comprehensive database of healthcare facilities. We harness major data collection efforts underway by OpenStreetMap, Google Maps and academic researchers to compile the most complete collection of facility locations to date. Leveraging the geographically variable strengths of our facility datasets, we use an established methodology4 to characterize travel time to healthcare facilities in unprecedented detail. We produce maps of travel time with and without access to motorized transport, thus characterizing travel time to healthcare for populations distributed across the wealth spectrum. We find that just 8.9% of the global population (646 million people) cannot reach healthcare within one hour if they have access to motorized transport, and that 43.3% (3.16 billion people) cannot reach a healthcare facility by foot within one hour. Our maps highlight an additional vulnerability faced by poorer individuals in remote areas and can help to estimate whether individuals will seek healthcare when it is needed, as well as providing an evidence base for efficiently distributing limited healthcare and transportation resources to underserved populations both now and in the future.

Efficacy of Itraconazole in the Prevention of Recurrence of Tinea Versicolor: A Three Year Follow Up.

Pityriasis versicolor (PV) also known as tinea versicolor, which is chronic and superficial fungal skin disease caused by Malassezia yeasts. A permanent cure may difficult to achieve and this may explain the long-term nature of the disease. Consequently, a preventive treatment regimen may help to prevent the recurrence of pityriasis versicolor. Whether, the recurrence of tinea versicolor could be prevented by monthly itraconazole treatment regimen after a short course of itraconazole therapy. Open treatment followed by a randomized, single blind placebo control trial. Multi-center trial was characterized by an open, active treatment phase with itraconazole followed by a randomized placebo controlled treatment for prevention of recurrence. A total 200 patients (150 male and 50 female) were included in this study and was given 200mg itraconazole daily for 7 days (treatment phase). Patients in whom tinea versicolor was mycologically cured divided into Group A and Group B. Active open treatment was followed by preventive itraconazole treatment 200mg twice daily in Group A and placebo in Group B monthly for 6 consecutive months. The patients were diagnosed clinically and confirmed by Wood's lamp examination and KOH microscopy. Clinical improvement in 90%, negative Wood's lamp examination in 86.5% and Mycological cure in 85.5% were found at the end of open treatment. The mycological cure, 171 subjects were taken into this study for preventive treatment phase and divided into two groups- Group A & Group B. Preventive treatment was given in Group A and placebo in Group B. After the preventive treatment, the end point (After 6 months), clinical improvement, negative Wood's lamp examination and mycological cure were found in 81(90%), 76(84.4%) and 75(83.3%) in Group A and 44(55%), 41(51.3%) and 42(52.5%) in Group B respectively. In preventive treatment phase, 1 patient in Group A did not complete the study. No patient experienced any serious adverse effects. Prevention of recurrence of Pityriasis versicolor with itraconazole is as effective as treatment.

Efficacy of Fexofenadine in the Treatment of Chronic Idiopathic Urticaria.

Urticaria is a common clinical condition that gives a major concern for physicians and patients alike. Urticaria is referred to as chronic when wheals occur daily or almost daily for a period of at least six weeks. The primary purpose of this study is to find out the efficacy of fexofenadine in the treatment of chronic idiopathic urticaria patients among the Bangladeshi population. This quasi-experimental study was performed in the Department of Dermatology & Venereology, Shaheed Ziaur Rahman Medical College Hospital, Bogura, Bangladesh from July 2013 to December 2013. Total 100 patients of chronic idiopathic urticaria aged 18 years and above with exclusion and inclusion criteria were selected. Then they were given fexofenadine 120mg twice daily for the treatment of chronic idiopathic urticaria for four weeks. A semi quantitative rating scales were used for the assessment of therapeutic efficacy before and after treatment. Data were collected in a pre-designed questionnaire by face-to-face interview and analyzed by the help of SPSS. Among the 100 respondents after one week of treatment, 8.0% had complete disappearance of symptoms, 10.0% had marked improvement, 40.0% had moderate improvement and 42.0% had slight improvement. After two weeks of treatment 35.0% had complete disappearance of symptoms, 13.0% had marked improvement, 12.0% had moderate improvement and 40.0% had slight improvement. After three weeks of treatment 40.0% had complete disappearance of symptoms, 13.0% had marked improvement, 35.0% had moderate improvement and 12.0% had slight improvement. After four weeks of treatment 42.0% had complete disappearance of symptoms, 24.0% had marked improvement, 26.0% had moderate improvement and 8.0% had slight improvement. The study concluded that fexofenadine is very effective in the treatment of chronic idiopathic urtecaria.

Frequency and Risk Factors of Erectile Dysfunction among Bangladeshi Adult Men with Type 2 Diabetes Mellitus.

Various forms of sexual dysfunction occur in men with diabetes mellitus (DM) including disorders of libido, ejaculatory problems, and erectile dysfunction (ED). This cross sectional study was conducted in a tertiary hospital of Bangladesh from December 2017 to May 2018 to find out the frequency and risk factors of ED in subjects with type 2 DM (T2DM). One hundred fifty (150) consecutive male patients with T2DM attending the Endocrinology outpatient department (OPD) of the hospital during the study period were evaluated for the presence of ED by using the International Index of Erectile Function-5 (IIEF-5) questionnaire; their socio-demographic, anthropometric, and clinical data were also recorded. Glycemic status was assessed by measurement of fasting plasma glucose (FPG) and HbA1c. Morning serum testosterone was measured in all. Among 150 subjects 68(45.3%) had ED; ED was mild in 14.7%, mild to moderate in 18.0%, moderate in 6.0% whereas severe ED was present in 6.7% of the subjects. The subjects with ED had higher mean age, longer duration of DM, higher body mass index (BMI), higher HbA1c, higher FPG, higher serum creatinine, and lower serum testosterone level than those without ED. Study subjects in the higher age group and higher duration of DM had higher frequencies of ED. IIEF-5 score showed significant negative correlation with age, duration of DM, HbA1c, fasting plasma glucose, serum creatinine and significant positive correlation with serum testosterone. In logistic regression analysis, duration of DM and serum testosterone were found be independent predictors of ED. Frequency of ED among Bangladeshi type 2 diabetic males is high; duration of DM and serum testosterone are independent predictors of ED in them.

Comorbidities in Patients with Psoriasis.

Psoriasis, a chronic inflammatory disease is associated with a long list of comorbidities. In our practice we like to draw attention in comorbidities of psoriatic arthritis and we are adapted with cardiovascular comorbidities. A great deal remains unknown about psoriasis associated comorbidities. An understanding of these comorbidity patterns can help us to ensure better care of patients with psoriasis. Objective of the study was to find out the comorbid conditions in the patients of psoriasis. This observational case control study was conducted 150 diagnosed cases of psoriasis and 150 age matched healthy control. Purposively 150 patients of psoriasis were selected from the Dermatology OPD of Bangabandhu Sheikh Mujib Medical University (BSMMU), Dhaka, Bangladesh from January 2017 to December 2018 as case. After a complete physical examination, a pre-designed structured questionnaire was fulfilled with patients and controls. To detect unknown comorbidities the following tests was done in both groups and compared: Blood sugar, urine routine and microscopic examination, serum creatinine, serum AST, ALT, GGT, and ALP levels measured by an enzymatic method, X-ray chest view, USG of whole abdomen/KUB. The diagnosed comorbidity was listed and referred for treatment accordingly. Charlson-age comorbidity index chart was used to estimate risk of mortality in two groups. The mean age of incident psoriasis was 38.64 years. Diabetes mellitus (4.67%), hypertension (4%), ischemic heart disease (IHD) (3.33%) were the top three comorbidities in patients with psoriasis. among them 11(7.33%) patients of psoriasis was with single comorbidity and 5(3.33%) of them was with multiple comorbidity. In control group 3(2%) participants was detected with comorbidity and that difference was significant statistically. In current study Charlson-Age Comorbidity index (CACI) was used as a tool to estimate the risk of mortality in two groups. The mean CACI score was 2.5 and 1 in two groups respectively and the difference was significant (p<0.05). The estimated risk of death (ERRD) score was calculated form CACI chart and the score was 2.78 and 1.47 in two groups respectively. There was no significant difference in two groups (p>0.05). The rate of occurrence of comorbidity was more in psoriasis group than in control. The listed comorbidity was in mild severity range but the risk of mortality was same in psoriasis group and control.

Relating N2O emissions during biological nitrogen removal with operating conditions using multivariate statistical techniques.

Multivariate statistical analysis was applied to investigate the dependencies and underlying patterns between N2O emissions and online operational variables (dissolved oxygen and nitrogen component concentrations, temperature and influent flow-rate) during biological nitrogen removal from wastewater. The system under study was a full-scale reactor, for which hourly sensor data were available. The 15-month long monitoring campaign was divided into 10 sub-periods based on the profile of N2O emissions, using Binary Segmentation. The dependencies between operating variables and N2O emissions fluctuated according to Spearman's rank correlation. The correlation between N2O emissions and nitrite concentrations ranged between 0.51 and 0.78. Correlation >0.7 between N2O emissions and nitrate concentrations was observed at sub-periods with average temperature lower than 12 °C. Hierarchical k-means clustering and principal component analysis linked N2O emission peaks with precipitation events and ammonium concentrations higher than 2 mg/L, especially in sub-periods characterized by low N2O fluxes. Additionally, the highest ranges of measured N2O fluxes belonged to clusters corresponding with NO3-N concentration less than 1 mg/L in the upstream plug-flow reactor (middle of oxic zone), indicating slow nitrification rates. The results showed that the range of N2O emissions partially depends on the prior behavior of the system. The principal component analysis validated the findings from the clustering analysis and showed that ammonium, nitrate, nitrite and temperature explained a considerable percentage of the variance in the system for the majority of the sub-periods. The applied statistical methods, linked the different ranges of emissions with the system variables, provided insights on the effect of operating conditions on N2O emissions in each sub-period and can be integrated into N2O emissions data processing at wastewater treatment plants.

Skin Biopsy and Histopathological Diagnosis of Dermatological Diseases.

Microscopic examination of skin and mucous membrane is an established investigation in diagnosis and follow up of many dermatological conditions frequently encountered during practice. Histopathological examination is performed with biopsied specimen from skin and or mucous membrane where required. However neither do all skin biopsies produce neither a conclusive diagnosis nor the dermatologists routinely perform this procedure to every patient they consult. This cross sectional descriptive study conducted by reviewing the records of all biopsied cases studied for histopathology in Mymensingh Medical College, Mymensingh and Shaheed Mansur Ali Medical College, Dhaka, Bangladesh from January 2012 to December 2016. The aim of this study was to investigate the favourable clinical diagnoses set by dermatologists when performing skin biopsy, the diagnoses reached by the dermatopathologists after microscopic examination, and the relationship between them and finally to comment on the instances that skin biopsy fails to fulfill the diagnostic task. Fourteen hundred and thirty six (1436) cases of skin biopsy were reviewed and descriptive statistics were performed. Maximum cases 39.1% (562) were in 2nd decade with almost equal sex distribution. The most frequently proposed clinical diagnoses included papulosquamous dermatoses 28.6% (410), whereas histological confirmation was in 13.1% (188). Histological diagnosis was more as nonspecific dermatitis 31.6% (454). After microscopic examination, a specific histological diagnosis was found in 83.5% (1199) of the cases and a consensus between clinical and histological diagnoses was observed in 69.2% (994). Neither histological diagnosis nor any feature consistent with clinical suspicion was observed in 10.1% (145) cases. Histopathological examination of skin biopsy is still a valuable diagnostic tool in many skin diseases and dermatoses with diagnostic dilemma. There are cases in which diagnostic inefficiency are being faced even after skin biopsy examination.

Current Trends of Using Systemic Antifungal Drugs and their Comparative Efficacy in Tinea Corporis and Tinea Cruris in Outpatient Department of Dermatology in a Tertiary Level Hospital.

Tinea corporis & cruris are one of the earliest known fungal infection and are very common throughout the world. Although tinea corporis and tinea cruris does not cause mortality but causes morbidity and poses a major health problem. This study was conducted to evaluate the Comparative Efficacy of Terbinafine and Fluconazole in the Treatment of Tinea corporis and Tinea cruris. This cross sectional comparative type of analytical study was carried out at the department of Pharmacology & Therapeutics with collaboration of Dermatology and Venereology in Mymensingh Medical College Hospital, Mymensingh, Bangladesh from January 2016 to December 2016. In this study 168 newly diagnosed Tinea corporis and Tinea cruris patient was purposively selected where pattern of comparative efficacy of terbinafine and fluconazole were analyzed. Among 168 patients most of the patients presented with tinea corporis (58.33%). Most patients belong to 21-30 years age group. Male female ratio in this study was 1.15:1. In this study 143 patients were treated by fluconazole 50mg once daily for 4 weeks and 25 patients were treated by terbinafine 250 mg once daily for 4 weeks. After 4 weeks, improvement rate by fluconazole was 86.02% and terbinafine 96.00%. The clinical score of both groups after 4th week of treatment, there was slight more reduction of clinical score in terbinafine using group than fluconazole using group. The difference between these two clinical score was not statistically significant (p>0.05). Although no significant difference was observed between these two groups of patient in clinical aspect, but due to its lower price and availability in the hospital, it is suggested that fluconazole is more suitable for the treatment of tinea corporis and tinea cruris.

Sexual Lifestyle, Risk Factors and Socioeconomic Status of the STD Patients in Bangladesh.

Sexually transmitted diseases (STDs) are increasing alarmingly with time among the young-adults in Bangladesh. The objective of the study was to investigate Sexual lifestyle, Risk Factors and Socioeconomic Status of the STD Patients. A total of 205 STD patients were selected following convenient method of sampling consistent with defined selection criteria from outpatient department of Skin and Venereal Disease of Mymensingh Medical College Hospital, Mymensingh. Period of data collection was from July 2014 to June 2015. The research instrument was an interviewer questionnaire and laboratory investigation reports. Results showed that the mean age of the respondents was 27±5.9 years of which 104(50.7%) unmarried and 95(46.3%) married. Level of education, 168(82.0%) of the STD patients were literate. Occupation of the STD patients, 201(98.0%) had specific occupation of which 74(36.1%) were businessmen, 48(23.4%) student, 24(11.7%) technical jobs, 20(9.8%) day labourer, 15(7.3%) household workers, 14(6.8%) service holders and 6(2.9%) were transport workers. Their average monthly income was Tk. 7892±6763. Majority of the STD patients 115((56.1%) expressed that they enjoyed extra-marital sex or illegal sex out of curiosity, 32(15.6%) habitual, 24(11.7%) to test sexual performance, 18(8.8%) inadequate response of the legal sex partners, 8(3.9%) hyper-sexuality and 8(3.9%) family disharmony. Most of the patients 200(97.6%) were heterosexual of which 165(80.5%) visited 1-10 sex partners, 18(8.8%) 11-20 sex partners and 22(10.7%) visited 21-100 sex partners in lifetime. In category of sex partners, 60(29.3%) were hotel-based sex partners, 111(54.1%) brothel-based, 20(9.8%) friends sex partners, 10(4.9%) street sex sellers and 4(2.0%) were residential sex partners respectively. Of them, 132(64.4%) did not use condom during sex, 65(31.7%) use it occasionally and only 8(3.9%) use condom regularly. Most of them 170((82.8%) had been suffering from gonococcal urethritis, 19(9.3%) non-gonococcal urethritis, 12(5.9%) genital herpes, and rest other specific infections. STDs were significantly (p<0.05) associated with category of sex partners and use of condom. Altering sexual lifestyle is still the only applicable way to stop this human catastrophe.

Effectiveness of Topical Corticosteroid, Topical Calcineurin Inhibitors and Combination of Them in the Treatment of Vitiligo.

Vitiligo is an acquired pigmentary skin disorder which is disfiguring and difficult to treat. Cure and response rates for vitiligo are significantly lower. This study was conducted to evaluate the effectiveness of topical corticosteroid, topical calcineurin inhibitors (tacrolimus) and combination of them in the treatment of vitilligo in two tertiary care Hospital, in the Department of Dermatology and Venereology OPD (out patient department) in Mymensingh Medical College Hospital and Jahurul Islam Medical College Hospital, Bajitpur, Kishoregonj from January 2015 to December 2015. Newly diagnosed 112 vitiligo patients, aged more than 1 year to 70 years were assigned for therapy and to observe the response. This study indicates that, in case of vitiligo treatment topical tacrolimus was the most effective drug. Topical tacrolimus, topical corticosteroid and combination of them are to be effective in the treatment of vitiligo with reduction in the number of vitiliginous spots by increased repigmentation. But topical tacrolimus was the most effective drug, as it caused highest percentage of repigmentation of vitiliginous spot.

Hepatitis-B Infections among the Injection Drug Abusers: An Emerging Risk in Public Health, Bangladesh.

The objective of the study was to determine the incidence of Hepatitis-B (HBV) infection among the injection drugs abusers (IDUs). The research work was a cross-sectional study. A total of 400 IDUs were selected from July 2012 to June 2013 at the Outpatient Department of the Central Drug Addiction Treatment Center, Tejgaon, Dhaka, Bangladesh. They were selected consecutively following the purposive sampling method on the basis of defined selection criteria. Research instruments were a pre-tested interviewer questionnaire and blood specimen. Results showed that 79.70%(315) of the IDUs were found literate and 20.3%(85) illiterate. In present occupation, majority of them 60.5%(242) had no work and 39.5%(158) specific occupation. The mean age of them was 27.9±6.4 years. In marital status, 46.5%(186) were unmarried, 20.7%(83) married after addiction and 30.3%(121) married before addiction. Majority of the IDUs 75.2%(289) started their addiction with cannabis. In addition to injection drugs use, all of them were multiple drug abusers. In response to the sharing of needle, 35.7%(143) of the IDUs shared needle uncommonly and 64.3%(257) did not shared it at all. Ninety-three percent (372) of them were heterosexual and polygamous having extramarital sex with multiple partners. The quality of sex-partners was wife, friends, brothel & hotel based sex sellers and street sex sellers. Majority of IDUs {82.0%(328)} did not use condom at all and 15.5(62) sold blood several times in their lifetime. Seven percent {7.0%(28)} injection drug abusers had been suffering from hepatitis-B virus (HBV) infection. HBV infection was found to be significantly (p≥0.05) associated with the quality of sex partners and number of sex partners, and age and marital status. There is no significant association with sharing of needle particularly occasional sharing of needle. Altering the behaviors of IDUs, especially their sexual lifestyles, drug habit, using of disposable syringe without sharing of needle, and also alternative preventive measures against injection drugs are still the applicable way to control spread of the HBV among the IDUs in Bangladesh.

Topical Tacrolimus versus Hydrocortisone on Atopic Dermatitis in Paediatric Patients: A Randomized Controlled Trial.

Atopic dermatitis (AD) is a chronic, inflammatory skin disease in early childhood. Atopic dermatitis is familial disease, often coexists with other atopic diseases with multiple risk factors associated with atopic eczema. The disease is more frequent in urban areas compared with rural areas. Changes in nutrition and a decrease in infant breast-feeding and respiratory allergies are contributory factors for the condition. A Randomized Controlled Trial (RCT) was carried to compare the efficacy and safety of Tacrolimus ointment with a topical corticosteroid reference therapy. A total 60 patients aged between 2 to 10 years, having atopic dermatitis for at least one year and comply Hanifin-Rajka criteria were selected using random number table and allocated into study and control groups through randomization. Study group was treated with topical Tacrolimus 0.03% twice daily for three weeks, while the control group was treated with 1% Hydrocortisone acetate for the same period. Both groups had a washed out phase for 2 weeks with a follow up period of 6 weeks. Eczema Area and Severity lndex (EASI) was assessed at baseline and three weeks after treatment. Efficacy was evaluated at each visit by six clinical signs of atopic dermatitis through measurement of the affected surface area and the EASI score in each of four body regions. Before intervention, in study group mean EASI score was 11.29 with a SD of 2.14, while in control group it was 11.05 with a SD of 2.46. Difference was statistically insignificant (p>0.05). At the end of the treatment, in study group mean EASI score was 4.86 with a SD of 1.01, while in control group it was 7.97 with a SD of 1.80. Statistically high significant difference was observed between EASI scores of two groups before and after the treatment (p<0.001). After getting treatment with Tacrolimus, median reduction of EASI score was 56.07 in study group, while getting treatment with Hydrocortisone, median reduction of EASI score was 27.16. Difference was highly significant (p<0.001). It is evidenced that Tacrolimus ointment (0.03%) acts as an effective as well as safe non-steroidal topical therapy for the treatment of dermatitis in paediatric patients.

Cutaneous anthrax in a school teacher.

Cutaneous anthrax is an infection of the skin caused by Bacillus anthracis. This is a report of a case of cutaneous anthrax attending outpatients of Mymensingh Medical College Hospital in October, 2010. The infected person was a retired school teacher with a very good body build. He reported to handle cow flesh about 4-5 days ago, developed few painless papules over shin of right leg, which gradually became large bullae and blackish eschar developed over the lesion. Smears from the lesions were investigated which confirmed the causative agent B. anthracis. The patient was treated with oral Ciprofloxacin (500mg) twice daily for seven days which cured the infection as observed on his subsequent follow up visits on 7 and 14 days later. Oral Ciprofloxacin is found effective as recommended by the World Health Organization.

Pattern of mental illness on substance abusers.

The aim of this study was to investigate mental illnesses among the substance abuse dependent populations. A total of 1076 substance abusers were recruited from the Outpatient Department of the Central Drug Addiction Treatment Center, Tejgaon, Dhaka from July 2008 to June 2009. They sought detoxification therapy voluntarily at this centre. The research participants were selected consecutively following the defined selection criteria. Research instruments were interviewer-administered questionnaire and standard mental state examination scales. Of the 1076 substance abusers, 82.6% had been using heroin currently and rest of them used phensedyl followed by injection drugs and cannabis with a period ranged 2-30 years. Results showed that 91.3% of the substance abusers had been suffering from insomnia and 75.0% had altered food habit. About 49.0% showed disturbed behaviors and 45.2% had been suffering from sexual dysfunctions. Around 32.0% of the substance abusers had been suffering from nonspecific generalized anxieties and 72.7% were found in abnormal mood/affects. A striking finding was that 7.3% of the substance abusers had been suffering from perceptual and/or thought disturbances. In conclusion, 7.3%-92.5% of the substance abusers had been suffering from mental illnesses. Insomnias, decreased intake of food and taste preference, irritable mood/affects, loss of interest in sex and non-specific anxieties were highly prevalent among them. Medical management and altering lifestyle are still the only applicable way to control this human catastrophe.

Instability of human rotavirus G genotypes circulating in a rural area of Bangladesh.

A total of 280 fecal specimens from patients with acute gastroenteritis attending one rural hospital (Dharmapasha health complex, Sunamgonj) in Bangladesh from August 2004 to May 2006 were tested for rotavirus by Polyacrylamide Gel Electrophoresis (PAGE). The diversity of rotavirus was investigated using electropherotyping and reverse transcription-PCR amplification of the VP7 and VP4 genes. The electrophoretic patterns of dsRNA of rotavirus showed 9 different migrations (6 long and 3 short) by PAGE. In the year 2004-2006, group A rotavirus was detected in 112 out of 280(40.0%) specimens. G and P genotyping was performed among the 46 representative positive specimens, 20(43.5%) were emerging strain G9P[8], which were associated with VP6 genotype II (subgroup II), and NSP4 genotype B, followed by 16(34.8%) G2P[4], 8(17.4%) G1P[8] and 2(4.4%) G4P[8] strains. G9P[8] was found to be the most predominant strain in 2004, but the prevalence rate abruptly decreased during the period 2005-2006. In addition G2P[4] was the most prevalent strain in 2005 and 2006. G1P[8] was less prevalent in the study period then the previous years. Nucleotide Sequence identity of VP7 gene of G9 rotaviruses were higher than 99.4% with each other and all the G9 rotavirus strains in this study clustered in a single branch of the phylogenetic tree. Nucleotide sequence identity of complete VP4 gene of P[8] rotaviruses were more than 99.7% with each other and all the P[8] rotavirus strains in this study grouped in a single cluster suggesting recent emergence from a common ancestor. An important finding of this study is that the genetic profile of rotavirus is changing within very short period in Bangladesh and continued surveillance of the circulating strains is necessary to detect new strains or new variants which can escape immune protection induced by available vaccines.

Investigation of self-organizing oscillator networks for use in clustering microarray data.

The self-organizing oscillator network (SOON) is a comparatively new clustering algorithm that does not require the knowledge of the number of clusters. The SOON is distance based, and its clustering behavior is different to density-based algorithms in a number of ways. This paper examines the effect of adjusting the control parameters of the SOON with four different datasets; the first is a (communications) modulation dataset representing one modulation scheme under a variety of noise conditions. This allows the assessment of the behavior of the algorithm with data varying between highly separable and nonseparable cases. The main thrust of this paper is to evaluate its efficacy in biological datasets. The second is taken from microarray experiments on the cell cycle of yeast, while the third and the fourth represent two microarray cancer datasets, i.e., the lymphoma and the liver cancer datasets. The paper demonstrates that the SOON is a viable tool to analyze these problems, and can add many useful insights to the biological data that may not always be available using other clustering methods.

Transport properties of CdS nanowire embedded poly(3-hexyl thiophene) nanocomposite.

Electrical transport properties of CdS nanowire embedded regioregular poly(3-hexyl thiophene) (P3HT) nanocomposite are investigated and the results are compared with those of the pure P3HT polymer. Both dc and ac conductivities of P3HT and CdS-P3HT nanocomposites show semiconducting nature and conductivity of CdS-P3HT is much less than that of the pure P3HT conducting polymer. The difference in the electrical behavior is attributed to the formation of nanowires in the CdS-P3HT nanocomposite. The dc conductivity data at high and low temperatures are qualitatively consistent with the optical-photon-assisted hopping and variable-range hopping models, respectively. However, the multiphonon-assisted hopping models of small polarons in nonadiabatic regime, which consider strong interactions with electrons with the optical as well as acoustical phonons, are the best to interpret quantitatively the experimental data in the entire temperature range for both P3HT and CdS-P3HT nanocomposites. We observe that the quantum tunneling model of small polarons is consistent with almost every respect of the loss data of P3HT conducting polymer, while for CdS-P3HT nanocomposite the ac conductivity varies with temperature in a different manner, which is explained in terms of simple quantum tunneling model of electrons in contrast to that of pure P3HT conducting polymer.

Classification of breast masses in mammograms using genetic programming and feature selection.

Mammography is a widely used screening tool and is the gold standard for the early detection of breast cancer. The classification of breast masses into the benign and malignant categories is an important problem in the area of computer-aided diagnosis of breast cancer. A small dataset of 57 breast mass images, each with 22 features computed, was used in this investigation; the same dataset has been previously used in other studies. The extracted features relate to edge-sharpness, shape, and texture. The novelty of this paper is the adaptation and application of the classification technique called genetic programming (GP), which possesses feature selection implicitly. To refine the pool of features available to the GP classifier, we used feature-selection methods, including the introduction of three statistical measures--Student's t test, Kolmogorov-Smirnov test, and Kullback-Leibler divergence. Both the training and test accuracies obtained were high: above 99.5% for training and typically above 98% for test experiments. A leave-one-out experiment showed 97.3% success in the classification of benign masses and 95.0% success in the classification of malignant tumors. A shape feature known as fractional concavity was found to be the most important among those tested, since it was automatically selected by the GP classifier in almost every experiment.

Genetic programming and feature selection for classification of breast masses in mammograms.

A dataset of 57 breast mass mammographic images, each with 22 features computed, was used in this investigation. The extracted features relate to edge-sharpness, shape, and texture. The novelty of this paper is the adaptation and application of genetic programming (GP). To refine the pool of features available to the GP classifier, we used five feature-selection methods, including three statistical measures -- Student's t-test, Kolmogorov-Smirnov Test, and Kullback-Leibler Divergence. Both the training and test accuracies obtained were above 99.5% for training and typically above 98% for testing.