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PubMed2005

Distribution of genes encoding putative virulence factors and fragment length polymorphisms in the vrrA gene among Brazilian isolates of Bacillus cereus and Bacillus thuringiensis.

One hundred twenty-one strains of the Bacillus cereus complex, of which 80 were isolated from a variety of sources in Brazil, were screened by PCR for the presence of sequences (bceT, hblA, nheBC, plc, sph, and vip3A) encoding putative virulence factors and for polymorphisms in variable-number tandem repeats (VNTR), using a variable region of the vrrA open reading frame as the target. Amplicons were generated from isolates of B. cereus and Bacillus thuringiensis for each of the sequences encoding factors suggested to play a role in infections of mammals. Intriguingly, the majority of these sequences were detected more frequently in Bacillus thuringiensis than in B. cereus. The vip3A sequence, which encodes an insecticidal toxin, was detected exclusively in B. thuringiensis. VNTR analysis demonstrated the presence of five different fragment length categories in both species, with two of these being widely distributed throughout both taxa. In common with data generated from previous studies examining European, Asian, or North American populations, our investigation of Brazilian isolates supports the notion that B. cereus and B. thuringiensis should be considered to represent a single species.

Animals↗

PubMed1965

Immunochemical studies on alpha-amylase. 3. Immunochemical relationships among amylases from various microorganisms.

Sirishinha, Stitaya (University of Rochester School of Medicine and Dentistry, Rochester, N.Y.), and Peter Z. Allen. Immunochemical studies on alpha-amylase. III. Immunochemical relationships among amylases from various microorganisms. J. Bacteriol. 90:1120-1128. 1965.-Immunochemical relationships among amylases obtained from a selected group of microorganisms were examined, and a cross-reaction was detected between the alpha-amylases of Bacillus stearothermophilus and B. subtilis. Immunodiffusion and quantitative precipitin studies, as well as cross-neutralization tests, indicate that B. stearothermophilus alpha-amylase reacts with a portion of antibody present in antisera to crystalline B. subtilis alpha-amylase. Amylases from these two species thus have some aspects of structure in common. Limited data obtained by immunodiffusion suggest that groupings which confer cross-reactivity to the B. stearothermophilus enzyme are lost after exposure to mercaptoethanol in the presence of ethylenediamine-tetraacetate, followed by treatment with iodoacetamide. With the antisera employed and within the concentration range examined, no immunochemical cross-reaction was observed among amylases from Aspergillus oryzae, B. subtilis, B. polymyxa, B. macerans, Pseudomonas saccharophila, and Euglena sanguinis. Immunoelectrophoresis of partially purified B. stearothermophilus alpha-amylase by use of antiserum to the crude enzyme, together with localization of amylase activity in immunoelectrophoretic plates, suggests that B. stearothermophilus alpha-amylase is antigenic in the rabbit.

Amylases↗

PubMed2000

Cooperation of multiple CCR5 coreceptors is required for infections by human immunodeficiency virus type 1.

In addition to the primary cell surface receptor CD4, CCR5 or another coreceptor is necessary for infections by human immunodeficiency virus type 1 (HIV-1), yet the mechanisms of coreceptor function and their stoichiometries in the infection pathway remain substantially unknown. To address these issues, we studied the effects of CCR5 concentrations on HIV-1 infections using wild-type CCR5 and two attenuated mutant CCR5s, one with the mutation Y14N at a critical tyrosine sulfation site in the amino terminus and one with the mutation G163R in extracellular loop 2. The Y14N mutation converted a YYT sequence at positions 14 to 16 to an NYT consensus site for N-linked glycosylation, and the mutant protein was shown to be glycosylated at that position. The relationships between HIV-1 infectivity values and CCR5 concentrations took the form of sigmoidal (S-shaped) curves, which were dramatically altered in different ways by these mutations. Both mutations shifted the curves by factors of approximately 30- to 150-fold along the CCR5 concentration axis, consistent with evidence that they reduce affinities of virus for the coreceptor. In addition, the Y14N mutation specifically reduced the maximum efficiencies of infection that could be obtained at saturating CCR5 concentrations. The sigmoidal curves for all R5 HIV-1 isolates were quantitatively consistent with a simple mathematical model, implying that CCR5s reversibly associate with cell surface HIV-1 in a concentration-dependent manner, that approximately four to six CCR5s assemble around the virus to form a complex needed for infection, and that both mutations inhibit assembly of this complex but only the Y14N mutation also significantly reduces its ability to successfully mediate HIV-1 infections. Although several alternative models would be compatible with our data, a common feature of these alternatives is the cooperation of multiple CCR5s in the HIV-1 infection pathway. This cooperativity will need to be considered in future studies to address in detail the mechanism of CCR5-mediated HIV-1 membrane fusion.

CD4 Antigens↗

PubMed2003

Risk factors for nuclear, cortical and posterior subcapsular cataracts in the Chinese population of Singapore: the Tanjong Pagar Survey.

AIM: To describe risk factors for nuclear, cortical, and posterior subcapsular (PSC) cataracts in Chinese Singaporeans. METHODS: A population based cross sectional study was carried out on ethnic Chinese men and women aged 40-81 years. A stratified, clustered, disproportionate (more weights to older people), random sampling procedure was used to initially select 2000 Chinese names of those aged 40-79 years from the 1996 electoral register in the Tanjong Pagar district in Singapore. Eligible subjects (n = 1717) were invited for a standardised ocular examination and interview at a centralised clinic, following which an abbreviated examination was conducted for non-respondents in their homes. Cataract was graded clinically using to the Lens Opacity Classification System (LOCS) III system. The main outcome measures were adjusted odds ratio for risk factors for specific cataract types (nuclear, cortical and PSC), any cataract and cataract surgery, examined in multiple logistic regression models. RESULTS: Out of the 1232 (71.8%) examined, 1206 (70.2%) provided lens data for this analysis. Increasing age was associated with all cataract types, any cataract, and cataract surgery. There was no significant sex difference in presence of any cataract, specific cataract types or cataract surgery. After controlling for age, sex, and other factors, diabetes was associated with cortical cataract (3.1; 95% CI: 1.6 to 6.1), PSC cataract (2.2; 95% CI 1.2 to 4.1), any cataract (2.0; 95% CI: 0.9 to 4.5), and cataract surgery (2.3; 95% CI: 1.3 to 4.1). Lower body mass index was associated with cortical cataract (1.8; 95% CI: 1.1 to 2.9; lowest versus highest quintile) and any cataract (2.3; 95% CI: 1.3 to 4.0). Current cigarette smoking was associated with nuclear cataract (1.7, 95% CI: 1.0 to 2.9; more than 10 cigarettes per day versus none). A non-professional occupation was associated with nuclear cataract (2.9; 95% CI: 1.5 to 5.8; for production or machine operators and 2.6; 95% CI: 1.2 to 5.5; for labourers or agricultural workers, both versus professionals). Lower education was associated with nuclear cataract (2.3; 95% CI: 1.0 to 5.2, none versus tertiary), while lower household income was associated with PSC cataract (4.7, 95% CI: 1.1 to 20.0; income S$4000). CONCLUSIONS: Age related cataracts are associated with a variety of risk factors among Chinese people in Singapore, similar to those reported in European, Indian, and African derived populations. These data support common aetiological mechanisms for age related cataracts, irrespective of ethnic origin.

Adult↗

PubMed2004

Public attitudes towards the use of primary care patient record data in medical research without consent: a qualitative study.

OBJECTIVES: Recent legislative changes within the United Kingdom have stimulated professional debate about access to patient data within research. However, there is currently little awareness of public views about such research. The authors sought to explore attitudes of the public, and their lay representatives, towards the use of primary care medical record data for research when patient consent was not being sought. METHODS: 49 members of the public and four non-medical members of local community health councils in South Wales, UK gave their views on the value and acceptability of three current research scenarios, each describing access to data without patient consent. RESULTS: Among focus group participants, awareness of research in primary care was low, and the appropriateness of general practitioners as researchers was questioned. There was general support for research but also concerns expressed about data collection without consent. These included lack of respect and patient control over the process. Unauthorised access to data by external agencies was a common fear. Current data collection practices, including population based disease registers elicited much anxiety. The key informants were equally critical of the scenarios and generally less accepting. CONCLUSIONS: This exploratory study has highlighted a number of areas of public concern when medical records are accessed for research without patient consent. Public acceptability regarding the use of medical records in research cannot simply be assumed. Further work is required to determine how widespread such views are and to inform those advising on confidentiality issues.

Access to Information↗

PubMed1995

Pleural malignant mesothelioma and non-occupational exposure to asbestos in Casale Monferrato, Italy.

OBJECTIVES: To assess and quantify the occurrence of pleural malignant mesotheliomas in people who neither experienced occupational exposure to asbestos nor were married to (or known to live with) workers exposed to asbestos in the workplace. The study was conducted in the area of the local health authority of Casale Monferrato, in north western Italy, where a large factory that produced asbestos cement was active up to 1985. No other major activities related to asbestos have ever been present in the area. METHODS: A retrospective survey covering the period 1980 to 1991 identified 126 incident pleural malignant mesotheliomas histologically diagnosed among residents in the local health authority (population at the 1981 census 98,000). Submission of 83 of 95 cases diagnosed during 1980-9 for revision by a panel of five expert pathologists led to the exclusion of 21. The 31 cases diagnosed in 1990-1 were not submitted for revision. For 64 of the 105 retained cases, information derived from different sources (rosters of the employees in the asbestos cement factory dated back to 1907, list of their spouses, clinical records) did not suggest occupational or paraoccupational exposure to asbestos. RESULTS: Incidence excludes cases for which there was some suggestion of occupational or paraoccupational exposure to asbestos. Incidence of histologically confirmed malignant mesothelioma among residents in the local health authority (annual x 100,000; age adjusted) was 4.2 in men and 2.3 in women (based on 26 and 18 cases respectively). In both sexes, rates in 1985-9 were higher than in the previous quinquennium. Corresponding estimates for 1990-1 (based on unrevised diagnoses) suggest similar rates in men and women. CONCLUSION: Rate ratios which are four to six times those measured by conventional Italian cancer registries can hardly be totally explained by bias produced by lack of recognition of occupational or paraoccupational exposure. The problem of proving this type of negative data is common to other circumstances of alleged cancer clusters of environmental (non occupational) origin.

Adult↗

PubMed1994

Setting up regional audit in genitourinary medicine and HIV: the south east Thames experience.

Audit at regional level is a useful complement to local audit, especially in small specialties. Regional audit can reduce professional isolation and lead to the development of uniformly high standards in the care given by a variety of providers. The development of regional audit in genitourinary medicine in South East Thames (UK), and of HIV medicine in South Thames, is described. Meetings are held quarterly, and concentrate on standard setting and development of guidelines. Information about the practice of individual units is collected by questionnaire, the results presented, and guidelines developed. Participation in completing questionnaires and attending the meetings is good. Regional guidelines in eleven topics have been produced, and methods of auditing changes in practice are now being assessed. A regional common data-set is being developed to assist in the audit process.

Ambulatory Care↗

PubMed2006

Association between Chlamydia pneumoniae antibodies and wheezing in young children and the influence of sex.

BACKGROUND: The proposed association between Chlamydia pneumoniae (Cpn) infection and wheezing needs further clarification. METHODS: Serum samples obtained from 1581 children aged 4 years in a population based cohort were tested for antibodies to Cpn and IgE antibodies to common allergens. Data on environmental factors and disease were collected prospectively from birth. RESULTS: The occurrence of IgG antibodies to Cpn at 4 years of age was associated with reported wheezing at different ages; however, these findings were most often not significant. In girls, the occurrence of anti-Cpn IgG was associated with wheezing at the ages of 1, 2, and 4 years (odds ratios (ORs) 3.41 (95% confidence interval (CI) 1.46 to 7.96), 2.13 (95% CI 1.02 to 4.44), and 2.01 (95% CI 1.14 to 3.54), respectively), and even higher ORs were observed for each age category when only high level antibody responses to Cpn were analysed. At the time of blood sampling the association between anti-Cpn IgG and wheezing was restricted to girls without atopic sensitisation (OR 2.39 (95% CI 1.25 to 4.57). No associations with wheezing were detected in boys, in whom IgE sensitisation was inversely associated with the presence of anti-Cpn IgG (OR 0.49 (95% CI 0.26 to 0.90)). CONCLUSIONS: This study suggests an association between evidence of earlier Cpn infection and a history of wheezing in young girls. Infection with Cpn may be an important risk factor for wheezing and possibly for non-atopic asthma, predominantly in girls.

Antibodies, Bacterial↗

PubMed2002

A variable minisatellite sequence in the chloroplast genome of Sorbus L. (Rosaceae: Maloideae).

The chloroplast genome is now known to be more variable than was once thought. Reports of RFLP (restriction fragment length polymorphism) and sequence variation, as well as variation in chloroplast microsatellites, are common. Here, data are presented on the variability of a minisatellite sequence in the chloroplast genome of Sorbus species. RFLP analysis of a PCR product comprising the region between the trnM and rbcL genes of nine Sorbus species identified seven size variants. Sequencing revealed the observed size polymorphism to be due to differences in the number of copies of an imperfect 9-bp motif. A more intensive survey of the variability of the minisatellite was undertaken in populations of Sorbus aucuparia. The potential uses of such regions in chloroplast DNA are discussed and a possible mechanism for the evolution of the minisatellite is presented.

Base Sequence↗

PubMed2003

Coronary artery imaging with multidetector CT: visualization issues.

Noninvasive imaging of the coronary arteries has attracted growing interest in the past few years. One of the possible acquisition techniques is multidetector computed tomography (CT) that produces large three-dimensional (3D) data sets that require visualization techniques for data evaluation. The objective of this article is to increase knowledge of possible 3D visualization techniques together with their advantages and disadvantages for the routine evaluation of cardiac data sets. Common imaging techniques available to the radiologist at standard workstations are multiplanar reformation (MPR), oblique MPR, curved MPR, maximum-intensity projection (MIP), shaded-surface display, and direct volume rendering. Each of these techniques has its advantages and disadvantages for the visualization of the coronary artery tree. Several additions to the basic techniques have been developed to overcome some of their shortcomings. Different clinical examinations, such as stent evaluation, stenosis evaluation, and bypass evaluation, require different visualization techniques. The choice of preferred technique for each clinical study depends on the advantages and disadvantages of the various techniques as described in the literature. Because of the large number of possible settings and projection angles, it is important for users to interactively manipulate the images and review the whole vessel volume rather than just looking at static reformatted images. Errors such as findings of false stenoses can be avoided by means of accurate and appropriate use of software features. This requires training of users both with regard to the capabilities of the software and the background of the different techniques and their possible pitfalls. The authors believe that volume rendering of the whole heart is useful for anatomic evaluation of the coronary arteries. For more detailed observation of specific lesions, slab imaging with volume rendering or MIP is required.

Coronary Angiography↗

PubMed1994

Failure of hemoconcentration during standing to reveal plasma volume decline induced in the erect posture.

The hypothesis was tested that the hemoconcentration observed during standing provides erroneous information about the induced plasma volume (PV) decline. Male volunteers (n = 10) stood quietly for 15 min after supine rest. On standing arterial hemoglobin (Hb) rose slowly to reach an increase of 5.9 +/- 0.3% (SE) after 15 min. Early after resuming the supine position, Hb increased further to 9.2 +/- 0.5% above control level and then declined gradually. Venous antecubital blood from the left arm supported horizontally at heart level in both the supine and standing positions (no hydrostatic load) showed very similar changes. However, Hb in venous blood collected during standing from the right arm held in the natural dependent position rose much more markedly than that in arterial blood and in venous blood from the horizontal arm (470 +/- 122, 105 +/- 24, and 55 +/- 7% greater increase at 5, 10, and 15 min, respectively). Taken together, these observations indicated that 1) analyses of arterial blood sampled from the standing subject grossly underestimated the prevailing "overall" hemoconcentration and PV decline, a phenomenon ascribed to incomplete mixing of blood between dependent and nondependent regions; 2) arterial blood sampled from the recumbent subject early (60 s) after completion of standing reflected the "true" overall intravascular hemoconcentration, with a calculated PV decline of no less than 511 +/- 27 ml, because the supine position facilitated proper mixing of blood between circulatory compartments; 3) data from common venous sampling from the dependent arm during standing primarily reflected a regional hemoconcentration (fluid loss) in the arm rather than PV decline; and 4) short-term quiet standing caused a more prominent and hemodynamically important decrease in PV than usually believed.

Adult↗

PubMed2002

Neurochemical phenotypes of MRF neurons influencing diaphragm and rectus abdominis activity.

In prior studies that used transneuronal transport of isogenic recombinants of pseudorabies virus, we established that medial medullary reticular formation (MRF) neurons sent collateralized projections to both diaphragm and abdominal muscle motoneurons. Furthermore, inactivation of MRF neurons in cats and ferrets increased the excitability of diaphragm and abdominal motoneurons, suggesting that MRF neurons controlling respiratory activity are inhibitory. To test this hypothesis, the present study determined the neurochemical phenotypes of MRF premotor respiratory neurons in the ferret by using immunohistochemical procedures. Dual-labeling immunohistochemistry combining pseudorabies virus injections into respiratory muscles with the detection of glutamic acid decarboxylase-like immunoreactive and glutamate-like immunoreactive cells showed that both GABAergic and glutamatergic MRF neurons project to respiratory motoneurons, although the latter are more common. These data suggest that the role of the MRF in respiratory regulation is multifaceted, as this region provides both inhibitory and excitatory influences on motoneuron activity.

Animals↗

PubMed2001

Bronchopulmonary dysplasia and surfactant.

Bronchopulmonary dysplasia (BPD) is the most common respiratory complication in preterm infants who survive prolonged mechanical ventilation. Exogenous surfactant administration clearly reduces the severity of respiratory distress syndrome (RDS) and consequently the need for aggressive ventilation and prolonged oxygen therapy. However, the overall incidence of BPD has not decreased but in fact may even have increased after the introduction of surfactant therapy. There are several reasons for the lack of effect on the incidence of BPD. First, surfactant therapy and antenatal steroids have markedly increased survival of the smallest infants, i.e. those at higher risk of BPD. Second, there has been a change in the pathogenesis and the presentation of BPD. While the classic BPD was mainly the consequence of barotrauma and oxygen toxicity, the new BPD seen in the surfactant era results from the interaction of many factors that lead to prolonged mechanical ventilation and colonization of the airway with pathogens that may trigger an inflammatory cascade. While the overall incidence of BPD has not been substantially modified by surfactant therapy, the more severe cases of BPD have become less common. The data regarding the effect of surfactant administration on the incidence and severity of BPD is conflicting. There is substantial evidence that the administration of exogenous surfactant, either as prophylaxis or as a treatment in infants with established RDS, can reduce neonatal mortality and the occurrence of BPD or death. The data also suggest that prophylactic or early administration is more effective than late treatment in reducing mortality and BPD or death. No clear difference has been documented between natural or synthetic surfactant treatment in terms of their effect on incidence of BPD or mortality. The lack of consistency in the results with surfactant replacement may reflect the changing pathogenesis of BPD and the multiplicity of factors involved among which surfactant deficiency is only one.

Bronchopulmonary Dysplasia↗

PubMed1981

Clinical trial of a new antigonadotropic substance, 2,6-cis-diphenylhexamethylcyclotetrasiloxane, in cancer of the prostate. A pilot study.

An organic siloxane compound, 2,6-cis-diphenylhexamethylcyclotetrasiloxane, (Cisobitan) has been shown to possess antigonadotropic properties. In this study it has been tried in prostatic cancer. 9 patients received the drug in the dose of 4-5 mg/kg body weight. General condition and subjective response, cytologic changes and semiquantitative scintigraphic changes of metastases were recorded, as well as common laboratory data. In this limited trial, Cisobitan was not adequate for tumour palliation. In a few instances subsequent oestrogen treatment was more effective. No side effects of Cisobitan were noted for periods up to 6 months. Further studies may be of value, perhaps using a higher dose.

Aged↗

PubMedDate not supplied

Epidemiology of aortic aneurysms: I. Mortality trends in the United States, 1951 to 1981.

The trends in mortality from aortic aneurysms in the United States from 1951 through 1981 were studied. Annual age-specific and age-adjusted mortality for aortic aneurysms were calculated for white males, white females, nonwhite males, and nonwhite females. For all four groups, a constant increase in age-adjusted mortality was noted for the period 1951 to 1968 (an average annual increase of 17% for white males, 12% for white females, 14% for nonwhite males, and 15% for nonwhite females), plateauing in 1968, with a slight decline noted after 1968. The increase corresponded to an increase in the total number of U.S. aortic aneurysm deaths from about 2500 to approximately 14,000. The decline was most notable for dissecting aneurysms. Analysis of the age-specific rates by birth cohort suggests that mortality is increasing with each subsequent cohort. Analysis of specific aneurysm types (dissecting, thoracic, abdominal, and not otherwise specified) suggests that abdominal ones are most common. These data are reviewed in the context of existing knowledge of aortic aneurysms. Further studies to validate these findings and to develop hypotheses for the etiology of aortic aneurysms are needed.

Adult↗

PubMed1998

Differences in the mechanical properties of the rat carotid artery in vivo, in situ, and in vitro.

The elastic properties of carotid arteries of spontaneously hypertensive rats (SHR) and normotensive controls (Wistar-Kyoto rats [WKY]) were examined in vivo, in situ, and in vitro. The changes of internal diameter were measured with a high-resolution A-mode echo-tracking device simultaneously with the intra-arterial pressure at the carotid. The internal diameter at mean arterial blood pressure (MBP) was substantially smaller in vitro than in vivo in SHR (-33.8%) and WKY (-48.3%). The arterial distensibility was lower in vitro in all arteries compared with in vivo conditions (SHR, -30.1%; WKY, -60.4%; at MBP) despite a reduced incremental elastic modulus in vitro (SHR, -56.9%; WKY, -45.1%; at MBP). However, the in vitro and in vivo measurements show consistent elastic behavior of the carotid arteries between both strains of rats. Carotid arteries from WKY were also examined in situ. Although no significant reduction in internal diameter could be observed in situ, distensibility was dramatically decreased (-87% at MBP). These results emphasize the importance of considering the original vascular geometry when determining elastic properties of arteries. We conclude that experimental conditions are likely to be a critical determinant for the assessment of the mechanical properties of conduit vessels.

Animals↗

PubMedDate not supplied

Multiple regression of predictors and criteria of dental school performance.

This study reports normative data for 370 students admitted to the UCLA School of Dentistry, data on commonly used performance predictors, and the regression equation best fitted for forecasting performance in this school. Most variance was associated with denatl school grade point average, National Board Dental Examination averages, and clinical performance. Best predictors were achievement level and trend in preadmission academic performance. The selection interview and high school preformance were also evaluated as predictor criteria.

Age Factors↗

PubMed2004

Role of stereoselective assays in bioequivalence studies of racemic drugs: have we reached a consensus?

The existence of stereoselectivity in metabolism and drug disposition, coupled with the existence of genetic polymorphisms and modulation of enantiomeric kinetics via special delivery systems, provides some compulsion to assess bioequivalence using stereoselective data. However, examination of the literature suggests that nonstereoselective data are commonly used for the bioequivalence assessment of drug racemates.

Humans↗