Biomedical subjects

K Roy

Publications and source records attributed to K Roy.

At least 19 recordsLinked to original sources

PubMed2006

Causes of loss of Sonali chickens on smallholder households in Bangladesh.

In a 1-year-long prospective longitudinal study, we determined the causes of loss of 'Sonali' (male symbol Rhode Island Red x female symbol Fayoumi) chickens at key-rearers' households of the smallholder livestock development project-2 (SLDP-2) area in Bangladesh. A key rearer is a smallholder of chickens in the 'village poultry-production chain' (undertaken by SLDP-2 under the financial assistance of the DANIDA) who rears at least five Sonali and some 'Deshi' (non-descriptive and indigenous) chickens in their homesteads based on semi-scavenging system. The aim of this program is to ameliorate poverty, especially among women. Two co-ordination centers (set at the Potuakhali and Noakhali districts) supervised the development activities. We selected two upazilas (lower administration units) randomly from each of the two districts and in every selected upazila, we selected at random 125 key-rearer households. Incidence rates of loss of Sonali chickens from disease, predation, selling and slaughtering were 0.025, 0.023, 0.081 and 0.039 per bird-month at risk, respectively. The major predators of Sonali chickens in the study area were foxes, a kind of wild cat (Felis chaus), mongooses and human thieves. Colibacillosis (both single and mixed infections) had a contributory role in the death of 28% of dead Sonali birds collected for diagnosis; salmonellosis, Newcastle disease and internal parasites contributed to the next highest (14, 11and 10%) proportional mortalities.

Animal Husbandry↗

PubMed2006

QSPR of the bioconcentration factors of non-ionic organic compounds in fish using extended topochemical atom (ETA) indices.

Bioconcentration refers to the absorption or uptake of a chemical from the media to an organism's tissues leading to greater concentration in tissues than that in the surrounding environment. Considering the importance of bioconcentration from the viewpoint of ecological safety assessment, a QSPR study was conducted based upon log BCF of 122 non-ionic organic compounds in fish using the recently introduced extended topochemical atom (ETA) indices. In deriving the models, principal component factor analysis (FA) followed by multiple linear regression (MLR), stepwise regression, partial least squares (PLS) and principal component regression analysis (PCRA) were applied as statistical tools. This was repeated with non-ETA (topological and physicochemical) descriptors and a combination set including both the ETA and non-ETA descriptors. The ETA indices suggested negative contributions of functionalities of nitro, amino and hydroxy substructures and positive contributions of branching, volume and functionality of chloro substituents. Again, the predictive ability of the developed models was compared with the previously reported models. Finally the validation of all the QSAR models was discussed based on random division, sorted log BCF data and K-means clusters for the factor scores of the original variable (ETA) matrix without the response property values. The results suggest that ETA parameters are sufficiently rich in chemical information to encode the structural features contributing to the bioconcentration of the non-ionic organic compounds in fish and thus these merit further assessment to explore their potential in QSAR/QSPR/QSTR modelling.

Animals↗

PubMed2005

Digit preference in Goldmann applanation tonometry: the hedgehog effect.

PURPOSE: Digit preference is a subconscious bias towards numbers that end in certain digits. We conducted a study to assess for digit preference in intraocular pressure measurement using the Goldmann applanation tonometer. DESIGN: Prospective study with masked and unmasked phases. METHODS: The study was conducted in general ophthalmic clinics in a District General Hospital in Blackpool, United Kingdom, by 6 clinical ophthalmologists. Consecutive right eye intraocular pressure measurements were collected for a 2-month period for the masked phase and were repeated for the unmasked phase. The proportion of even numbers was the main outcome measure. RESULTS: Six ophthalmologists completed both phases: 555 of 917 readings were even in the masked phase (P = .075), and 679 of 1056 readings were even in the unmasked phase (P = .022). CONCLUSIONS: Our results suggest that digit preference influences measurements from the Goldmann applanation tonometer and that this persists when observers are aware of digit preference. This bias may influence both clinical decision-making and trial results.

Bias↗

PubMed2005

Severe illness and death among injecting drug users in Scotland: a case-control study.

Between April and September 2000, 60 injecting drug users in Scotland died or were hospitalized with severe illness. Laboratory investigations suggested that Clostridium novyi and other bacteria were important aetiological agents. To determine associated environmental/behavioural factors a case-control study was undertaken with 19 'definite' and 32 'probable' cases in Glasgow, Scotland. For every deceased case (n=19), up to three proxy individuals were interviewed. Three controls were identified for each case. Multivariate logistic regression analyses compared (i) all cases and controls; (ii) definite cases and matched controls; (iii) probable cases and matched controls. In all three analyses injecting into muscle or skin and injecting most of the time with a filter used by someone else were the variables most strongly associated with illness. Comparing only muscle-injecting cases and controls, cases were significantly more likely to have injected larger amounts of heroin per average injection than were controls. The findings make an important epidemiological contribution to the understanding of the public health and clinical implications of the contamination of illicit drugs by histotoxic clostridia.

Adult↗

PubMed2005

Philadelphia chromosome positive essential thrombocythemia with dilated cardiomyopathy.

We report here an unusual case of a 30-year old male patient with essential thrombocythemia (ET) and dilated cardiomyopathy, who on further investigation was found to have Philadelphia chromosome positive (Ph+) cells in the bone marrow. The reverse transcriptase-polymerase chain reaction (RT-PCR) test on his peripheral blood leucocytes revealed b2a2 transcript of the bcr-abl fusion gene. Literature shows that the boundary line between Ph+ essential thrombocythemia and chronic myeloid leukemia (CML) is getting blurred day by day. Each one may be a part of the spectrum of a single clonal proliferative disease. Association of dilated cardiomyopathy with ET has not been reported.

Adult↗

PubMed2004

Separation of 90Y from 90Sr using zirconium vanadate as the ion exchanger.

The sorption and desorption behaviour of several radionuclides, including 241Am, 152,154Eu, 233U, 137Cs, 90Sr and 90Y was studied under varying acidities using zirconium vanadate as ion exchanger. The sorption follows the order: Cs > Eu > Am >Y > U, while Sr was not taken up by the ion exchanger. A radiochemical separation scheme for the 90Y daughter from its 90Sr parent using zirconium vanadate ion exchanger has been developed. The exchanger was synthesized and characterized in our laboratory.

Journal Article↗

PubMed2004

Trends in hospital admission for stroke in Calgary.

BACKGROUND: Stroke incidence has fallen since 1950. Recent trends suggest that stroke incidence may be stabilizing or increasing. We investigated time trends in stroke occurrence and in-hospital morbidity and mortality in the Calgary Health Region. METHODS: All patients admitted to hospitals in the Calgary Health Region between 1994 and 2002 with a primary discharge diagnosis code (ICD-9 or ICD-10) of stroke were included. In-hospital strokes were also included. Stroke type, date of admission, age, gender, discharge disposition (died, discharged) and in-hospital complications (pneumonia, pulmonary embolism, deep venous thrombosis) were recorded. Poisson and simple linear regression was used to model time trends of occurrence by stroke type and age-group and to extrapolate future time trends. RESULTS: From 1994 to 2002, 11642 stroke events were observed. Of these, 9879 patients (84.8%) were discharged from hospital, 1763 (15.1%) died in hospital, and 591 (5.1%) developed in-hospital complications from pneumonia, pulmonary embolism or deep venous thrombosis. Both in-hospital mortality and complication rates were highest for hemorrhages. Over the period of study, the rate of stroke admission has remained stable. However, total numbers of stroke admission to hospital have faced a significant increase (p=0.012) due to the combination of increases in intracerebral hemorrhage (p=0.021) and ischemic stroke admissions (p=0.011). Sub-arachnoid hemorrhage rates have declined. In-hospital stroke mortality has experienced an overall decline due to a decrease in deaths from ischemic stroke, intracerebral hemorrhage and sub-arachnoid hemorrhage. CONCLUSIONS: Although age-adjusted stroke occurrence rates were stable from 1994 to 2002, this is associated with both a sharp increase in the absolute number of stroke admissions and decline in proportional in-hospital mortality. Further research is needed into changes in stroke severity over time to understand the causes of declining in-hospital stroke mortality rates.

Alberta↗

PubMed2004

Hepatitis A virus and injecting drug misuse in Aberdeen, Scotland: a case-control study.

To describe an epidemiological investigation of an outbreak of hepatitis A virus (HAV) infection among injecting drug users in Aberdeen, Scotland. A case-control study to determine whether transmission was facilitated by poor personal hygiene or through sharing injecting equipment. Cases were more likely to report not washing their hands after using the toilet [odds ratio (OR) = 12.9, 95% confidence interval (CI) = 1.58-105.89] or before preparing food (OR = 4.0, 95% CI = 1.01-15.8), and less likely to have washed their hands prior to preparing drugs (OR = 10.67, 95% CI = 2.14-53.07). Cases were also more likely to report recipient sharing of needles/syringes (OR = 8.27, 95% CI = 1.68-40.57), and to have had injecting contact with someone who was jaundiced (OR = 29.4, 95% CI = 3.18-271.44). The results indicate that the lack of hygiene within the context of individuals gathering to prepare and inject drugs provides ample opportunity for the transmission of HAV. Although the promotion of good hygiene and the avoidance of sharing injecting equipment are important measures in preventing HAV transmission, they are unlikely to effect major behavioural change. Such measures should, therefore, be reinforced by routinely offering HAV vaccine to injectors.

Adolescent↗

PubMed2003

Distinguishing early and late onset non-melancholic unipolar depression.

AIM: We seek to determine whether unipolar non-melancholic major depression commencing early in life has a differing clinical picture, and whether it may have differing determinants. METHODS: We study a sample of such patients, comparing those with depression onset in their first 25 years against residual subjects, matching exactly by sex and controlling for age. RESULTS: There were no differences in current depression severity. Despite early onset subjects having a distinctly younger current mean age, they had a lifetime pattern of both greater depression chronicity and disability, and judged themselves as less likely to have benefited from any antidepressant medication or psychotherapy. 'Phenotypically' early onset subjects did not differ in terms of 'depressive' symptoms, but were distinguished by a greater irritability, which we interpret as reflecting a temperament dimension influencing symptom expression. Multivariate analyses indicated that the clinical pattern in those with an early onset was distinguished by more evident irritability and anxiety, that there was a distinct familial contribution to early onset depression, that its forerunners were an early personality style of behavioural inhibition or shyness, and that they were more likely to use alcohol and illicit drugs. CONCLUSIONS: While early onset unipolar depression is unlikely to be a pure depressive 'type', it may well be that certain familial temperament characteristics lead to an early onset of depression marked by irritability, a process that invokes a spectrum disorder concept linking temperament style and the depressive manifestations. Early onset depression is indicative of a poor prognosis, both in terms of response to interventions and in regard to chronicity and disability.

Adult↗

PubMed2003

Hepatitis C infection among dental personnel in the West of Scotland, UK.

Hepatitis C virus (HCV) is considered a serious occupational hazard for healthcare workers, particularly those performing exposure-prone procedures. In the UK, the majority of dental procedures are classified as exposure prone. In order to gauge the prevalence and determinants of infection among dental healthcare workers, a voluntary anonymous survey of HCV infection among primary care dental workers employed in the West of Scotland was undertaken, in which occupational and personal risk data were collected in parallel with a blood specimen. The overall prevalence of HCV antibodies was 0.1% (1/880, 95% CI 0-0.6); this is no greater than the estimated prevalence of HCV infection in the local population. Personal risk data collected suggested that the single infection identified was acquired through a non-occupational route. These results suggest that HCV infection is not a major occupational risk for dental healthcare workers.

Dental Auxiliaries↗

PubMed2003

Risk of hepatitis C virus transmission from patients to surgeons: model based on an unlinked anonymous study of hepatitis C virus prevalence in hospital patients in Glasgow.

BACKGROUND: The risk of a surgeon acquiring the hepatitis C virus (HCV) through occupational exposure is dependent on the prevalence of HCV infection in the patient population, the probability of a percutaneous injury transmitting HCV, and the incidence of percutaneous injury during surgery. AIMS: To estimate the prevalence of HCV infection in the adult surgical patient population in North Glasgow and thereafter estimate the risk of HCV transmission to surgeons through occupational exposure. METHODS: The prevalence of HCV infection was estimated through the unlinked anonymous testing of samples from male surgical patients, aged 16-49 years, in two North Glasgow hospitals from 1996 to 1997, and adjusting these data for age and sex. Using published estimates of the incidence of percutaneous injury during surgery and percutaneous injury transmitting HCV, the risk of occupational transmission of HCV to surgeons was then derived. RESULTS: The estimated prevalence of anti-HCV infection for all adult patients in the two hospitals combined was 1.4% (cardiothoracic/cardiology 0.8%, orthopaedics/rheumatology 1.4%, general surgery/ENT 2.0%). The estimated probability of HCV transmission from an HCV infected patient to an uninfected surgeon was 0.001-0.032% per annum (0.035-1.12% risk over a 35 year professional career). CONCLUSIONS: The risk of an individual surgeon acquiring HCV through occupational exposure is low, even in an area with an extremely high prevalence of HCV among its injecting drug using population. Surgeons however should be encouraged to observe universal precautions and present for assessment after needlestick injuries to protect themselves and their patients from this insidious infection.

Adolescent↗

PubMed2002

Protective immune responses elicited in mice by immunization with formulations of poly(lactide-co-glycolide) microparticles.

Parenteral administration of microparticle encapsulated DNA elicits immune responses to the encoded antigens. Experiments were performed to test whether the addition of certain lipophilic agents to such formulations enhanced the activity of a beta-galactosidase (beta-gal) DNA vaccine. Addition of either taurocholic acid (TA) or monomethoxy polyethylene-glycol-distearoylphosphatidylehanolamine (PEG-DSPE) increased the efficiency of DNA encapsulation. Immunization of mice with encapsulated DNA formulations containing either compound significantly increased the number of antibody positive responders over that achieved with non-lipid containing particles. Moreover, responding animals demonstrated trends towards higher antibody titers and increased T cell responses. Tumor protection against the CT26.CL25 tumor cell line was demonstrated with lipid and non-lipid containing formulations. These results are the first demonstration of protection obtained by parenteral administration of PLG encapsulated DNA vaccines.

Animals↗

PubMed2002

Monitoring hepatitis C virus infection among injecting drug users in the European Union: a review of the literature.

Hepatitis C virus (HCV) among injecting drug users (IDUs) is one of the European Union's (EU) major public health problems. This review examines the current state of knowledge regarding HCV among IDUs in EU countries. Studies published between January 1990 and December 2000, were identified through a computerized search (MEDLINE and EMBASE). Ninety-eight studies have reported prevalence for HCV among groups of IDUs in all EU countries except Luxembourg. The prevalence of anti-HCV ranged from 30 to 98%. Incidence rates ranged from 6.2 to 39.3 per 100 person years. This review provides a comprehensive examination of HCV infection among IDUs in the countries of the EU, and quite clearly demonstrates that the quality and epidemiological relevance of the studies published varies widely. Thus, the reported data may not reflect accurately the current or recent past prevalence of HCV among IDUs in the EU. A strategic approach to the surveillance of HCV among IDUs in the EU, utilizing robust and consistent methods, is required urgently.

Adult↗

PubMed2002

Gender differences in depression risk and coping factors in a clinical sample.

OBJECTIVE: To examine gender differences in depression risk and coping factors in a clinical sample of patients with a diagnosis of DSM-IV major depression. METHOD: Patients were assessed for substance use and abuse, family history of psychiatric disorder, interpersonal depressogenic factors and lifetime history of anxiety disorders. Trait anxiety, coping styles when depressed, parental bonding, marital features and personality style were also measured. Patients were reassessed at 12-month follow-up. RESULTS: There were few gender differences in experience of depression (either in duration, type or severity prior to treatment) in a group with established episodes of major depression but women reported more emotional arousability when depressed. Women reported higher rates of dysfunctional parenting and childhood sexual abuse, and rated their partners as less caring and as more likely to be a depressogenic stressor. Men were more likely to have a generalized anxiety disorder at assessment, to use recreational drugs prior to presentation. Men were rated as having a more rigid personality style and 'Cluster A' personality traits both at assessment and follow-up. CONCLUSION: There were few gender differences in severity or course of established episodes of major depression. Gender differences were related to levels of arousal, anxiety disorders, and repertoires for dealing with depression, rather than depressive symptoms per se.

Adaptation, Psychological↗

PubMed2002

Examining the utility of a temperament model for modelling non-melancholic depression.

OBJECTIVE: Depression is currently modelled dimensionally, along severity, duration and recurrency dimensions. An alternative model allows dimensional expressions of temperament and personality to influence risk to onset as well as persistence. Here, we examine the utility of a temperament model. METHOD: A questionnaire assessing temperament dimensions and a number of depression variables was administered to a large routine general practice sample and with the temperament measure also completed by a small clinical sample. RESULTS: 'Anxious worrying' and 'irritable' dimensions were identified as internalizing and externalizing expressions of a trait anxiety dimension, three other 'temperament' dimensions (i.e. 'introversion', 'self-centred' and 'obsessive') were refined, while a 'self-blame' dimension intruded into the factor analytic solution. High scores on the 'anxious worrying' dimension were associated with all depression parameters. The 'irritable', 'introversion' and 'self-blame' dimensions were less clearly linked with depression variables, while higher scores on the 'self-centred' and 'obsessional' dimensions did not appear to increase the chance of depression onset, persistence or recourse to treatment. CONCLUSION: A temperament-based approach appears to have some conceptual utility in modelling depression, and particularly, the non-melancholic disorders. It is likely, however, to require complementing with refined at-risk personality dimensions.

Adult↗

PubMed2002

Multiple molecular targets of indole-3-carbinol, a chemopreventive anti-estrogen in breast cancer.

The mechanism of action of the anti-estrogen indole-3-carbinol (I3C), present in cruciferous vegetables, is being examined in our laboratory with a view to promote the use of this naturally occurring chemopreventive as an alternative to synthetic anti-estrogens in human breast cancer. Our previous results clearly demonstrated that despite its low affinity for the estrogen receptor (ER), I3C abrogated estradiol-mediated cellular and biochemical effects in estradiol-responsive cells and tissues. In an earlier report, we identified ER phosphorylation as one of the targets of I3C, and in this communication we describe the consequence of inhibition of ER phosphorylation. Estradiol-induced DNA-binding proteins that bound to several DNA-responsive elements were inhibited by I3C and this effect was not at the level of DNA-protein physical interaction as inclusion of I3C in vitro in the reaction mix did not affect the binding. We analyzed the spectrum of genes induced by estradiol and modulated and/or intercepted by I3C. Our results conclude that although estradiol-mediated functions are affected by I3C, its biochemical targets are multiple and some of these may be modulated by the oligomeric products of I3C.

Anticarcinogenic Agents↗

PubMed2001

Spatial patterns of morphological diversity across the Indo-Pacific: analyses using strombid gastropods.

Biological diversity can be measured using various metrics, but existing knowledge of spatial patterns of diversity is largely based on species counts. There is increasing evidence that trends in species richness might not match trends in other biodiversity metrics, such as morphological diversity. Here, we use data from a large group of Indo-Pacific gastropods (family Strombidae) to show that the species richness of a region is a poor predictor of the morphological diversity present there. Areas with only a few species can harbour an impressive array of morphologies and, conversely, morphological diversity in the most species-rich regions is no higher than in regions with half their taxonomic diversity. Biological diversity in the Pacific is highly threatened by human activity and our results indicate that, in addition to species richness, morphological diversity metrics need to be incorporated into conservation decisions.

Animals↗

PubMed2001

MyoD can induce cell cycle arrest but not muscle differentiation in the presence of dominant negative SWI/SNF chromatin remodeling enzymes.

Cell cycle arrest is critical for muscle differentiation, and the two processes are closely coordinated but temporally separable. SWI/SNF complexes are ATP-dependent chromatin-remodeling enzymes that have been shown to be required for muscle differentiation in cell culture and have also been reported to be required for Rb-mediated cell cycle arrest. We therefore looked more closely at how SWI/SNF enzymes affect the events that occur during MyoD-induced myogenesis, namely, cell cycle regulation and muscle-specific gene expression, in cells that inducibly express dominant negative versions of Brahma (BRM) and Brahma-related gene 1 (BRG1), the ATPase subunits of two distinct SWI/SNF complexes. Although dominant negative BRM and BRG1 inhibited expression of every muscle-specific regulator and structural gene assayed, there was no effect on MyoD-induced activation of cell cycle regulatory proteins, and thus, cells arrested normally. In particular, in the presence or absence of dominant negative BRM or BRG1, MyoD was able to activate expression of p21, cyclin D3, and Rb, all of which are critical for cell cycle withdrawal in the G1/G0 phase of the cell cycle. These findings suggest that at least one basis for the distinct mechanisms that regulate cessation of cell proliferation and muscle-specific gene expression during muscle differentiation is that SWI/SNF-mediated chromatin-remodeling enzymes are required only for the latter.

Base Sequence↗