Single-molecule imaging of stochastic interactions that drive dynein activation and cargo movement in cells.

Cytoplasmic dynein 1 (dynein) is the primary minus end-directed motor protein in most eukaryotic cells. Dynein remains in an inactive conformation until the formation of a tripartite complex comprising dynein, its regulator dynactin, and a cargo adaptor. How this process of dynein activation occurs is unclear since it entails the formation of a three-protein complex inside the crowded environs of a cell. Here, we employed live-cell, single-molecule imaging to visualize and track fluorescently tagged dynein. First, we observed that only ∼30% of dynein molecules that bound to the microtubule (MT) engaged in minus end-directed movement, and that too for a short duration of ∼0.6 s. Next, using high-resolution imaging in live and fixed cells and using correlative light and electron microscopy, we discovered that dynactin and endosomal cargo remained in proximity to each other and to MTs. We then employed two-color imaging to visualize cargo movement effected by single motor binding. Finally, we performed long-term imaging to show that short movements are sufficient to drive cargo to the perinuclear region of the cell. Taken together, we discovered a search mechanism that is facilitated by dynein's frequent MT binding-unbinding kinetics: (i) in a futile event when dynein does not encounter cargo anchored in proximity to the MT, dynein dissociates and diffuses into the cytoplasm, (ii) when dynein encounters cargo and dynactin upon MT binding, it moves cargo in a short run. Several of these short runs are undertaken in succession for long-range directed movement. In conclusion, we demonstrate that dynein activation and cargo capture are coupled in a step that relies on the reduction of dimensionality to enable minus end-directed transport in cellulo and that complex cargo behavior emerges from stochastic motor-cargo interactions.

Discovery biology of neuropsychiatric syndromes (DBNS): a center for integrating clinical medicine and basic science.

BACKGROUND: There is emerging evidence that there are shared genetic, environmental and developmental risk factors in psychiatry, that cut across traditional diagnostic boundaries. With this background, the Discovery biology of neuropsychiatric syndromes (DBNS) proposes to recruit patients from five different syndromes (schizophrenia, bipolar disorder, obsessive compulsive disorder, Alzheimer's dementia and substance use disorders), identify those with multiple affected relatives, and invite these families to participate in this study. The families will be assessed: 1) To compare neuro-endophenotype measures between patients, first degree relatives (FDR) and healthy controls., 2) To identify cellular phenotypes which differentiate the groups., 3) To examine the longitudinal course of neuro-endophenotype measures., 4) To identify measures which correlate with outcome, and 5) To create a unified digital database and biorepository. METHODS: The identification of the index participants will occur at well-established specialty clinics. The selected individuals will have a strong family history (with at least another affected FDR) of mental illness. We will also recruit healthy controls without family history of such illness. All recruited individuals (N = 4500) will undergo brief clinical assessments and a blood sample will be drawn for isolation of DNA and peripheral blood mononuclear cells (PBMCs). From among this set, a subset of 1500 individuals (300 families and 300 controls) will be assessed on several additional assessments [detailed clinical assessments, endophenotype measures (neuroimaging- structural and functional, neuropsychology, psychophysics-electroencephalography, functional near infrared spectroscopy, eye movement tracking)], with the intention of conducting repeated measurements every alternate year. PBMCs from this set will be used to generate lymphoblastoid cell lines, and a subset of these would be converted to induced pluripotent stem cell lines and also undergo whole exome sequencing. DISCUSSION: We hope to identify unique and overlapping brain endophenotypes for major psychiatric syndromes. In a proportion of subjects, we expect these neuro-endophenotypes to progress over time and to predict treatment outcome. Similarly, cellular assays could differentiate cell lines derived from such groups. The repository of biomaterials as well as digital datasets of clinical parameters, will serve as a valuable resource for the broader scientific community who wish to address research questions in the area.

A comparative study of radiofrequency assisted versus microdebrider assisted turbinoplasty in cases of inferior turbinate hypertrophy.

Nasal obstruction is the most common complaint among patients presenting to otolaryngologists which disturbs the quality of life of the patient. The anterior end of inferior turbinate is in the narrowest part of nasal airway, enlargement of which causes significant nasal obstruction. In our, prospective and interventional, study a comparison was made between the results of bipolar radiofrequency assisted turbinoplasty and microdebrider assisted turbinoplasty in patients with chronic nasal obstruction due to inferior turbinate hypertrophy, not responding to medical treatments. The cases were randomly divided into radiofrequency (RF) and microdebrider (MD) groups, each consisting of 30 cases. Nasal obstruction, sneezing, itching in nose, rhinorrhea, intra operative bleeding, duration of surgery, post operative bleeding, post operative pain and crusting were the parameters recorded preoperative, intra operative and post operatively at 1 week, 1, 3 and 6 months. For bleeding and crusting standard 4-point scale was used. Rest of the symptoms were assessed subjectively on standard visual analogue scale (0-10). The statistical analysis was done by student's t test. Postoperatively, all the preoperative symptoms were significantly improved up to 6 months in group RF as well as group MD, but there were three cases of recurrence at 6th months of postoperative period in group RF. However, we recommend MD assisted inferior turbinoplasty under local anaesthesia in view of long term symptom relief and lesser recurrence.

Assessment of swallowing and its disorders-a dynamic MRI study.

Magnetic resonance imaging overcomes the limitations of videofluoroscopy in assessing without radiation exposure. The clinical utility of dynamic MRI for swallowing disorders is not well documented. This study demonstrates the feasibility of using dynamic MRI in assessment of swallowing disorders. Ten normal and three brainstem lesion patients participated in this study. GE Signa HDxt 1.5 Tesla MRI scanner with head-and-neck coil as a receiver and fast imaging employing steady state acquisition sequence was used. The swallow was analyzed in terms of symmetry and amplitude of movements of velum, faucial pillars, tongue, epiglottis and cricopharyngeous and images from the sagittal, coronal and axial planes. In sagittal plane posterior movement of tongue and its compression on velum, elevation of hyoid bone, elevation of larynx and lid action of epiglottis, in the coronal view the symmetrical movements of the faucial pillars and pharyngeal constrictor muscles and in axial plane three anatomical landmarks were targeted based on their role in swallowing, viz. velum, epiglottis and cricopharyngeous were studied. In brainstem lesion individuals, posterior movement of tongue, and elevation of larynx were not seen. Asymmetrical movements of faucial pillars and cricopharyngeous muscle were appreciated in the dynamic MRI. This demonstrates that, dynamic MRI is an efficient tool to understand the swallowing physiology and helps the speech language pathologist in modifying the swallowing maneuvers. Dynamic MRI is an effective tool in assessing swallowing and its disorders. This muscle specific information is not appreciated in videofluoroscopy and this information is necessary to modify the therapy maneuvers.

Knowledge, attitude and screening practices of general dentists concerning oral cancer in Bangalore city.

CONTEXT: Oral cancer presents with high mortality rates, and the likelihood of survival is remarkably better when detected early. The dental profession shares an important responsibility toward early screening, prompt referral and treatment. AIMS: The aim of the present study was to assess the oral cancer knowledge, attitude and screening practices among dental practitioners in Bangalore city. MATERIALS AND METHODS: This descriptive cross-sectional study was conducted using a 24-item self-administered questionnaire involving private dental practitioners of Bangalore city. A total of 1556 private dental practitioners of Bangalore made up the sampling frame of the study, and a sample of 250 dentists was found to be sufficient. Two hundred and fifty dentists were selected by cluster random sampling. The institutional review committee approved the study. Data were entered using SPSS 13.01. RESULTS: A total of 250 practicing dentists were approached, of which 240 participated in the study. Among the various risk factors for causing oral cancer, the use of alcohol was identified as a major risk factor by 238 (99%) dentists. The high-risk age group for oral cancer was identified as the fourth and fifth decades by 143 (59%) dentists. Adequate training for providing oral cancer examinations was acquired by 164 (68%) of the dentists. Two hundred and thirty-seven (98%) dentists strongly agreed that patients should be referred to specialists if they suspected oral cancer in any lesion. No more than 37% of the dentists routinely practiced complete oral cavity examination on all patients who attended their practice. A mere 31% of the dentists educated their patients on the adverse effects of these habits and assisted them in cessation programmes. CONCLUSIONS: These findings concerning dentists' knowledge and opinions related to oral and pharyngeal cancer suggest strongly that educational interventions for practitioners and dental students are necessary. We contend that an offering of continuing dental education programs would go a long way to enhance the prevention and early diagnosis of oral cancer.

Synthesis and biological evaluation of novel Mannich bases of 2-arylimidazo[2,1-b]benzothiazoles as potential anti-cancer agents.

A new series of Mannich bases of 2-arylimidazo[2,1-b]benzothiazoles were synthesized and evaluated for their anti-cancer activity. These compounds showed better cytotoxicity activity with IC(50) values ranging from 2.8 to 8.0 µM in HepG2, MCF-7 and HeLa cell lines. Further mechanism aspects responsible for the anti-cancer activity of two promising compounds 3c and 3f in HepG2 cell line were studied. Interestingly, 3c, 3f induced G2/M cell cycle arrest with down regulation of cyclin B and up regulation of Chk2 protein. Moreover, compounds 3c, 3f also showed the characteristic features of apoptosis such as enhancement in the levels of caspase-3. Treatments with compounds led to a decrease in levels of vital cell proliferation proteins such as Jun (C-Jun, JunB), p38 MAPK, p-JNK and PKCα. The compound 3f of the series could be considered as the potential lead for its development as a novel anti-cancer agent.

Usage of personal-protection measures against mosquitoes and the low prevalences of Wuchereria bancrofti microfilaraemia in the Indian city of Chennai.

The usage of personal-protection measures against mosquitoes and the prevalence of Wuchereria bancrofti microfilaraemia were assessed in different areas of the city of Chennai, a large urban area in southern India. Most of the households investigated (75% to 92%, depending on socio-economic status) used some form of personal protection (such as mosquito coils, vaporizing mats and liquids and mosquito nets). The study households spent a mean (S.D.) of 109.45 (141.65) Indian rupees/month on personal protection, such expenditure increasing significantly with increasing household income (F=2.95; P=0.03). Over the last three decades the prevalence of W. bancrofti microfilaraemia has been slowly declining in Chennai. Most of the 'moderate-income' areas of the city investigated in the present study appeared free of such microfilaraemia, and the prevalences recorded in about half of the low- and very-low-income study areas did not exceed 1.0%. The mean prevalences recorded in the moderate-, low- and very-low-income areas were 0.51%, 1.15% and 1.30%, respectively. Given their very low prevalences of microfilaraemia, relatively good housing, sanitation and health care and extensive use of personal-protection measures, the 100 million Indians living in (mostly urban) moderate- and high-income areas may not require active mass drug administrations (MDA) against lymphatic filariasis. The need to develop simple methods to stratify urban areas, into those that require and those that do not require active MDA, remains. If lymphatic filariasis is to be eliminated from India in a reasonable time-frame, at least as a public-health problem, MDA should now be focused on the poorer localities.

A campaign of "communication for behavioural impact" to improve mass drug administrations against lymphatic filariasis: structure, implementation and impact on people's knowledge and treatment coverage.

In the mass drug administrations (MDA) that form the principal strategy of the Global Programme to Eliminate Lymphatic Filariasis, treatment coverages of at least 65%-80% will be needed if the programme is to be successful. In the Indian state of Tamil Nadu, where treatment coverages were typically <65%, a comprehensive strategy of advocacy and communication, called the "communication for behavioural impact" (COMBI) campaign, has been developed and implemented, in an attempt to improve treatment coverage. This strategy combined advocacy, aimed at state-, district- and village-level administrations, with communication activities targeted at individual communities. The main aim was to alter the behaviour of many of those included in the rounds of MDA, so that they would be more likely to accept and consume the diethylcarbamazine tablets offered to them. The COMBI campaign had two variants, COMBI(+) and the more intensive COMBI(+ +), each of which has been implemented in six districts. Both the variants included the "personal selling" of treatment, via door-to-door visiting by a total of 113,500 filaria-prevention assistants. These assistants were able to visit 34%-49% of the households in each target community. In the COMBI(+ +) districts, up to 44% and 38% of households received information on lymphatic filariasis and its elimination via television commercials and posters, respectively. Overall, 78% of the villages in the COMBI(+ +) districts and 33% of those in the COMBI(+) districts were considered to have had good exposure to the communication campaign. At the end of this campaign about 30% more people (than pre-campaign) believed that lymphatic filariasis could be eliminated and many of those targeted considered lymphatic filariasis to be a dreadful disease, knew that a particular day had been designated "Filaria Day", and thought that the tablets offered in MDA should be consumed to prevent or eliminate the disease. Apparently as the result of the COMBI campaign, drug consumption increased, from 33% of those living in endemic communities, to 37% in the COMBI(+) districts and to 49% in the COMBI(+ +). Coverages as high as 65%-73% were recorded among those who had had the maximum exposure to the communication campaign. These results indicate that the COMBI campaign favourably changed the perception and behaviour of the people towards the elimination of lymphatic filariasis. The costs of the COMBI(+) and COMBI(+ +) strategies were only U.S.$0.002 and U.S.$0.009 per capita, respectively.

Laparoscopic adrenalectomy: Gaining experience by graded approach.

INTRODUCTION: Laparoscopic adrenalectomy (LA) has become a gold standard in management of most of the adrenal disorders. Though report on the first laparoscopic adrenalectomy dates back to 1992, there is no series of LA reported from India. Starting Feb 2001, a graded approach to LA was undertaken in our center. Till March 2006, a total of 34 laparoscopic adrenalectomies were performed with success. MATERIALS AND METHODS: The endocrinology department primarily evaluated all patients. Patients were divided into Group A - unilateral LA and Group B - bilateral LA (BLA). The indications in Group A were pheochromocytoma (n=7), Conn's syndrome (n=3), Cushing's adenoma (n=2), incidentaloma (n=2); and in Group B, Cushing's disease (CD) following failed trans-sphenoid pituitary surgery (n = 8); ectopic ACTH- producing Cushing's syndrome (n=1) and congenital adrenal hyperplasia (CAH) (n=1). The lateral transabdominal route was used. RESULTS: The age group varied from 12-54 years, with mean age of 28.21 years. Average duration of surgery in Group A was 166.43 min (40-270 min) and 190 min (150-310 min) in Group B. Average blood loss was 136.93 cc (20-400 cc) in Group A and 92.5 cc (40-260 cc) in Group B. There was one conversion in each group. Mean duration of surgical stay was 1.8 days (1-3 days) in Group A and 2.6 days (2-4 days) in Group B. All the patients in both groups were cured of their illness. Three patients in Group B developed Nelson's syndrome. The mean follow up was of 24.16 months (4-61 months). CONCLUSION: LA though technically demanding, is feasible and safe. Graded approach to LA is the key to success.

Situation analysis in a large urban area of India, prior to launching a programme of mass drug administrations to eliminate lymphatic filariasis.

The main strategy now adopted for the elimination of lymphatic filariasis (LF) is based on mass drug administrations (MDA). Annual administration of antifilarial drugs to 65%-80% of the population at risk of the disease is believed to be necessary if LF is to be eliminated, at least as a public-health problem, within a reasonable time-frame. To facilitate the development of drug-delivery strategies that are sufficient to ensure such high treatment coverages in large urban areas, a situation analysis was undertaken in the Indian city of Chennai. The subjects interviewed came from households with high, moderate, low or very low incomes. A lack of information on the prevalence and socio-economic impact of the disease meant that LF was not viewed as a major pubic-health problem in the study area, even though cases of elephantiasis and hydrocele were detected in 2%-8% and 7%-20% of the households investigated. Overall, 40% of the interviewees from very-low-income households and 78% of those from middle-income households knew that (the parasite causing) elephantiasis was transmitted by mosquitoes. Only 4% of the subjects from high-income areas and 1% of those from low-income areas were aware that filarial infection was a major cause of hydrocele. Most of the subjects (>55% of each of the four socio- economic groups considered) felt that they were not at risk of developing elephantiasis. When specifically asked, only 35% of the subjects from high-income households but 84% of those from low-income households said that they would be willing to consume tablets of an antifilarial drug (diethylcarbamazine) in MDA to eliminate LF. It is therefore unclear whether high-income households in urban areas should be included in MDA programmes. The interviewees felt that an intensive campaign of information, education, communication and advocacy would be necessary if an effective MDA-based programme were to be implemented. Drug distribution through the health services was the most preferred option.Clearly, factors such as a lack of appreciation of the socio-economic impact of LF, a general belief that the risk of elephantiasis is low, doubts about the need to include all sectors of the eligible population in MDA, and a common dependence on private practitioners make successful MDA against LF in urban areas a challenging task. On the positive side, however, an urban population is often covered by a huge network of colleges, private practitioners, non-governmental organizations and residents' associations, and such networks provide new opportunities in the development of effective drug-delivery strategies.

The mosquito problem and type and costs of personal protection measures used in rural and urban communities in Pondicherry region, South India.

Personal protection measures have become an important tool against mosquito nuisance. The severity of mosquito nuisance and the type and costs of personal protection measures in the Pondicherry region in South India have been investigated, using a structured questionnaire. The number of respondents sampled was 300 in the urban area and 100 in rural areas. 87 and 63% of the urban and rural respondents, respectively, felt that mosquito nuisance was severe in their locality. 83% of the urban and 27% of the rural respondents are aware that mosquitoes transmit diseases and were able to name at least one mosquito-borne disease. All the neighbourhood shops in urban and a majority in rural areas stocked personal protection products. As many as 99.3 and 73% of the urban and rural respondents, respectively, were found to use personal-protection measures during some or all seasons of the year. Mosquito coils were the most widely used measure in both urban and rural areas, followed by vaporising mats in the former and electric fans in the latter areas. 48 and 40% in urban and rural areas, respectively, used personal-protection measures daily. In urban areas 46% used the measures in more than one room. Only a small proportion (3-14%) used bed nets. The average monthly expenditure on the measures was Rupees (Rs.) 62.17 (US$ 1.30) (range: Rs. 0.00-500.00) in urban areas and Rs. 8.03 (US$ 0.17) (range Rs. 0.00-45.00) in rural areas. Annual expenditure on personal protection measures in urban areas amounted to 0.63% of the per capita income. 73.7% of the respondents in urban areas expressed satisfaction with the protective effect of the measures used by them. However, 46.3% of the urban and 15% of the rural respondents felt that the personal-protection measures are harmful to health. Some of the perceived harmful effects are allergy, breathing problems, cough and head ache.

Effectiveness of community and health services-organized drug delivery strategies for elimination of lymphatic filariasis in rural areas of Tamil Nadu, India.

Lymphatic filariasis (LF) is targeted for global elimination. Repeated annual single-dose mass treatment with antifilarials has been recommended as the principal strategy to achieve LF elimination. This requires an effective and sustainable strategy to deliver the drug, diethylcarbamazine (DEC), to communities. In this study, a new drug delivery strategy - community-directed treatment (comDT) - was developed and implemented and its effectiveness compared with that of the traditional health services-organized drug delivery, in rural areas of Tamil Nadu, India. Qualitative and quantitative data showed that the communities and health services were able to distribute the drug in almost all villages. The drug distribution rate and treatment compliance rate of comDT and health services treatment were statistically compared after adjusting them for clustering. Under the comDT 68% (n=20 villages; range: 0-97%) of the population received DEC, compared with 74% (n=20 villages; range: 48-95%) with the health services treatment strategy (P > 0.05). However, only about 53% (range: 0-91%) of comDT recipients and 59% (range: 32-79%) of those who received DEC from the health services consumed the drug (P > 0.05). Although statistically not significant, the distribution and compliance rates were lower under the comDT strategy. Also, the strategy's operationalization appears to be difficult because of some social factors, and the tradition of communities' dependence on health services for treatment, whereas health services-organized distribution was much less cumbersome and found to be more acceptable to people. However, the distribution (74%) and compliance rates (59%) achieved by health services were also only moderate and may not be adequate to eliminate LF in a reasonable time frame. Health services manpower alone may not be sufficient to distribute the drug. We conclude that drug distribution by health services is the best option for India and participation of the community volunteers and village level government staffs in the programme is necessary to effectively distribute the drug and attain the desirable levels of treatment compliance to eliminate LF.