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PubMed2006

Which two questions of Mini-Mental State Examination (MMSE) should we start from?

The MMSE is a simple and commonly used instrument to evaluate cognitive impairment. With the aim of enabling the examiner to skip a large portion of the MMSE when screening subjects with lower possibility of cognitive impairment, we examined the internal distribution of the MMSE scores among 792 older adults visiting a teaching hospital, a long-term care hospital, nursing homes, and a geriatric clinic. The correlation coefficients between the summed scores of any two items of MMSE and the total score were compared. A receiver operating characteristic (ROC) curve was drawn to show the sensitivity and the specificity of predicting cognitive impairment, which was defined by the total MMSE score being less than 24. The mean MMSE score was 20.5 +/- 6.9 (+/-S.D.). A good predictor for cognitive impairment was the summed scores of the time orientation and serial sevens with a sensitivity of 98.2% and a specificity of 69.2% if cut-off was set at 7/7+. This finding appears to help streamline the screening process for cognitive impairment in general elderly population.

Aged↗
PubMed2003

Flexibility analysis of enzyme active sites by crystallographic temperature factors.

Protein flexibility is inherent to protein structural behavior. Experimental evidence for protein flexibility is extensive both in solution and in the solid state. A major question is whether the flexibility observed in enzymes is simply an inherent property of proteins that must always be borne in mind or is essential for catalysis or substrate binding. The temperature factors or B-values, as determined crystallographically, are linearly related to the mean square displacement of an atom and give an indication of atomic flexibility in the crystalline state. In this paper, we describe the frequency distributions of the normalized B-factor (B'-factor) for the active site and non-active site residues in the selected 69 apo-enzymes. This analysis was performed over the entire sequences and for different structural subsets defined by the three-dimensional structure of proteins, as alpha-helices, beta-structures and coil conformation and buried and non-buried residues. The results show that in all cases, the active site residues predominantly occur in region of low B'-factor and the non-active site residues have a tendency to exist in the high B'-factor region. This observation suggests that the active site residues, in general, are less flexible than the non-active site residues and therefore the vibrational and the fast collective motions of the C(alpha) atoms of proteins appear not to have clear biological significance.

Amino Acids↗
PubMed2006

Beyond switches: ratcheting a particle energetically uphill with a compartmentalized molecular machine.

Here we correlate chemical (covalent), physical (thermodynamic), and statistical (population distribution) descriptions of behavior with the way that two new types of simple molecular machines (the threads of rotaxanes) perform the task of transporting a Brownian substrate (the rotaxane macrocycle) between two distinguishable binding sites. The first machine-substrate ensemble is a [2]rotaxane that operates through a mechanism that intrinsically causes it to change the average position of the macrocycle irreversibly. This contrasts with the behavior of classic stimuli-responsive molecular shuttles that act as reversible molecular switches. The second system is a compartmentalized molecular machine that is able to pump its substrate energetically uphill using the energy provided by a photon by means of an olefin photoisomerization. Resetting this compartmentalized molecular machine does not undo the work it has carried out or the task performed, a significant difference to a simple molecular switch and a characteristic we recognize as "ratcheting" (see Scheme 8). The ratcheting mechanism allows the [2]rotaxane to carry out the transport function envisaged for the historical thought-machines, Smoluchowski's Trapdoor and Maxwell's Pressure Demon, albeit via an unrelated mechanism and using an input of energy. We define and exemplify the terms "ratcheting" and "escapement" in mechanical terms for the molecular level and outline the fundamental phenomenological differences that exist between what constitutes a two-state Brownian switch, a two-state Brownian memory or "flip-flop", and a (two-stroke) Brownian motor. We also suggest that considering the relationship between the parts of a molecular machine and a substrate in terms of "statistical balance" and "linkage" could be useful in the design of more complex systems and in helping to understand the role of individual amino acids and peptide fragments during the directional transport of substrates by biological pumps and motors.

Journal Article↗
PubMed1998

Variations in angioplasty and bypass surgery.

OBJECTIVES: This article describes rates of and times to revascularization procedures for heart attack patients. DATA SOURCE: The data are from Statistics Canada's Person-Oriented Information Data Base. Hospital discharge records for heart attack patients were linked for fiscal years 1992/93 and 1993/94. ANALYTICAL TECHNIQUES: Hospital patients admitted between April 1 and September 30, 1993 with a primary diagnosis of acute myocardial infarction (AMI) were followed for six months to determine what percentage underwent percutaneous transluminal coronary angioplasty and/or coronary artery bypass graft surgery. Analyses of time-to-procedure were performed for those patients who had not been hospitalized for AMI in the previous 12 months. MAIN RESULTS: Approximately 24,000 Canadians were discharged from hospital during the first half of fiscal year 1993/94 with a diagnosis of AMI. Within six months, 8.7% had an angioplasty and 6.7% had a bypass; overall, 14.9% were revascularized. Women were less likely than men to have a bypass, but angioplasty rates did not differ significantly. The rate of revascularization declined with age. After adjusting for age and sex, rates were higher in the western provinces.

Adult↗
PubMed2003

Improved model based on the Weibull distribution to describe the combined effect of pH and temperature on the heat resistance of Bacillus cereus in carrot juice.

The effect of pH and temperature on the thermal inactivation of different strains of Bacillus cereus was modeled. Inactivation tests were carried out in carrot broth, following a full factorial design at four levels for temperature (from 90 to 105 degrees C, depending on the strain) and pH (6.2, 5.8, 5.2, and 4.7). Individual inactivation curves were analyzed by applying the Weibull model function (with percent discrepancy close to 20% for most cases), and the effects of pH and temperature on the scale parameter (designated D(beta)) and the shape parameter (beta) were also studied. Temperature and pH did not have a significant effect on the shape parameter (beta). The effect of temperature on the scale parameter was modeled by the zeta concept. The scale parameter decreased with pH, although the behavior of the strains was not homogeneous. Two global models with a small number of parameters were developed, providing a satisfactory description of the thermal inactivation of B. cereus, with percent discrepancy ranging from 18 to 25%.

Bacillus cereus↗
PubMedDate not supplied

Blunt diaphragmatic rupture in elderly patients.

BACKGROUND/AIMS: Severe blunt torso trauma can cause diaphragmatic rupture. Such trauma remains a diagnostic challenge to the trauma surgeon, particularly when the initial chest roentgenogram is unrevealing. Owing to age, preexisting diseases, and poor physiological reserves, elderly patients suffer higher mortality rates after trauma than young patients. The difference between elderly and young patients in terms of blunt diaphragmatic rupture is particularly interesting. METHODOLOGY: Records from 78 patients presenting with blunt diaphragmatic rupture at our hospital from July 1992 to January 2001 were retrospectively reviewed. Age, gender, co-morbid disease, trauma mechanism, associated organ injury, injury severity score, hemodynamic status on arrival at our Emergency Room, injury side and size of diaphragmatic rupture, delay before operation, and postoperative complications and mortality were determined for elderly (> or = 65 years) and young (<65 years) patients. RESULTS: 10 elderly and 68 young patients were collected and reviewed. Elderly patients had higher rate of preexisting disease (60% vs. 16.2%), associated injury of long bone fracture (60% vs. 23%), and initial normal chest roentgenogram (50% vs. 12%) and they had significant delays before operation. Only 20% of elderly patients were operated on within 24 hours of trauma, compared to 87% of young patients, and 50% elderly patients were actually operated on over a week after the trauma. Furthermore, no statistically significant differences existed between elderly and young patients in ISS (19.9 +/- 6.3 & 22.8 +/- 10.4), or the injury side of diaphragmatic rupture, although elderly patients did display shorter diaphragmatic ruptures (5.6 +/- 3.3 & 10.0 +/- 6.0cm, p<0.05), and longer periods on postoperative ventilatory support (17.7 +/- 21.2 & 3.2 +/- 5.0 days, p<0.05). Finally, elderly patients also had significantly higher rates of postoperative complications of pneumonia (30% & 5.9%), and mortality (50% & 2.9%) than young patients did. CONCLUSIONS: Compared to young patients, elderly patients with blunt diaphragmatic rupture had significantly higher rates of initial normal CXR, partly due to shorter length of diaphragmatic rupture, and partly due to ventilatory support, and consequent higher rate of delays before surgery. Furthermore, they also needed longer postoperative ventilator help, and prevailed higher rates of co-morbid disease, postoperative pneumonia, and mortality. Careful initial investigation and prudent radiological follow-up is recommended for elderly patients with severe blunt torso trauma.

Abdominal Injuries↗
PubMedDate not supplied

Improving procedures for recording suicide statistics.

OBJECTIVE: To explore the changing relationship between rates of suicide and undetermined death in Britain and Ireland. DESIGN: Longitudinal analysis of the official statistics relating to unnatural deaths in England and Wales and the Republic of Ireland between 1976 and 1992. MAIN OUTCOME MEASURES: Male and female rates of suicide and undetermined deaths for Ireland and England and Wales, age adjusted to the standard world population. Ratio of undetermined deaths to suicide. RESULTS: The official Irish male suicide rate is now much higher than that of England and Wales while the female rates are broadly similar. The rate of undetermined deaths has risen amongst English males and remained stable for females but has significantly fallen off among both Irish males and females. The proportion of deaths classified as 'undetermined' is now very much less in Ireland than in England and Wales. DISCUSSION: National plans for suicide prevention in either country cannot be properly audited unless improved procedures are put in place to increase the validity and reliability of the official suicide figures. Each country could beneficially learn from the other in this regard.

Adolescent↗
PubMed1999

The comparison of mixed distribution analysis with a three-criteria model as a method for estimating the prevalence of iron deficiency anaemia in Costa Rican children aged 12-23 months.

BACKGROUND: A maximum likelihood method of mixed distribution analysis (MDA) is presented as a method to estimate the prevalence of iron deficiency anaemia (IDA) in Costa Rican infants 12-23 months old. MDA characterizes the parameters of the admixed distributions of iron deficient anaemics and non-iron-deficient-anaemics (NA) from the frequency distribution of haemoglobin concentration of the total sample population. METHODS: Data collected by Lozoff et al. (1986) from 345 Costa Rican infants 12-23 months old were used to estimate the parameters of the IDA and NA haemoglobin distributions determined by MDA and the widely used three-criteria model of iron deficiency. The estimates of the prevalence of IDA by each of the methods were compared. The sensitivity and specificity of MDA compared to diagnosis by the three-criteria method were assessed. Simulations were carried out to assess the comparability of MDA and the three-criteria method in low and high prevalence scenarios. RESULTS: The mean and standard deviation (SD) of the NA haemoglobin distribution determined by both methods was 12.1 +/- 1.0 g/dL. The IDA haemoglobin distribution determined by MDA had a mean and SD of 10.2 +/- 1.3 g/dL while the IDA distribution by the three-criteria method had a mean and SD of 10.4 +/- 1.3 g/dL. The prevalences of IDA as estimated by MDA and the three-criteria method were 24% and 29%, respectively. The sensitivity and specificity of MDA were 95% and 97%, respectively. The performance of MDA was similar to the three-criteria method at a simulated high prevalence of IDA and less similar at a low prevalence of IDA. CONCLUSIONS: Compared to the reference three-criteria method MDA provides a more accurate estimate of the true prevalence of IDA than the haemoglobin cutoff method in a population of children aged 12-23 months with a moderate to high prevalence of IDA. MDA is a less costly method for estimating the severity of IDA in populations with moderate to high prevalences of IDA, and for assisting in the design, monitoring and evaluation of iron intervention programmes.

Anemia, Iron-Deficiency↗
PubMed2004

Association of serum antioxidants and risk of coronary heart disease in South Indian population.

BACKGROUND AND AIM: Higher prevalence of coronary heart disease (CHD) has been reported in south Indian population, which cannot be accounted for by the traditional risk factors like hyperlipidemia. Identification of new risk factors may help in treatment and prevention of CHD in this part of the world. In an attempt to investigate the causes of increased incidence of CHD in this part of the world, we intended to look for oxidative stress in our patients as a possible risk factor. As an initial step in this perspective, a case- control study was conducted to find out the serum antioxidant levels and their association with CHD in south Indian population. SETTINGS AND DESIGN: A tertiary care hospital; Case--control study. MATERIALS AND METHODS: One hundred thirty nine angiographically proven CHD patients (aged 29-75 years) were studied against 59 population based healthy controls (aged 29-72 years) free of CHD. Fasting serum cholesterol, triglycerides, HDL cholesterol, erythrocyte and plasma glutathione peroxidase and superoxide dismutase were estimated on automated clinical chemistry analyzer. LDL cholesterol and VLDL cholesterol were calculated. Vitamins A and E were estimated using high performance liquid chromatography (HPLC). STATISTICAL ANALYSIS: Unpaired t test was used to compare means. Binary logistic regression was done to find out the association between dependent and independent variables. RESULTS: Significantly higher levels of Total Cholesterol/HDL cholesterol and LDL cholesterol/HDL cholesterol ratio and lower HDL cholesterol levels were observed in patients when compared to controls. No significant difference of plasma and erythrocyte glutathione peroxidase and superoxide dismutase activity was observed between patients and controls. Significantly lower levels of vitamin E in patients than in controls was observed (P<0.001). Serum vitamin E was inversely associated with coronary heart disease even after controlling for age and other coronary risk factors (Odds ratio 0.898, 95% CI 0.826-0.976 P=0.01). CONCLUSIONS: The results of present study suggest that deficiency of vitamin E may be an independent risk factor of CHD. This study brings out the need for long- term monitoring of vitamin E supplementation as a preventive measure for CHD in the population studied.

Adult↗
PubMed2002

Season of birth in Japanese patients with schizophrenia.

A number of North American and European studies have observed a higher proportion of winter births in schizophrenia patients. Fewer studies have investigated this issue in Asian populations, and the findings are not as consistent as in the studies of Western populations. A statistically significant excess of winter births has not been observed in Japanese or Korean studies, while some of the studies found a decreased number of summer births among their patients. We further investigated the issue in Japanese patients with schizophrenia (n=2985). No significant excess of winter births was observed. Spearman correlation between schizophrenia births and ambient temperature was not significant. However, a decrease in the summer births was found, consistent with most of the previous Japanese studies. When analyzed by gender, a decrease in summer births was found in males, but not in females. In addition, a trend towards an increase in winter births was observed and Spearman correlation between low ambient temperature and schizophrenia births was significant in male subjects. More significant seasonality of birth in male patients than in female patients might be related to more susceptibility to pre- or perinatal disturbances in neurodevelopment in males than in females.

Age of Onset↗
PubMed2004

Noncancer disease incidence in atomic bomb survivors, 1958-1998.

We examined the relationships between the incidence of noncancer diseases and atomic bomb radiation dose using the longitudinal data for about 10,000 Adult Health Study (AHS) participants during 1958-1998. The current report updates the analysis we presented in 1993 with 12 additional years of follow-up. In addition to the statistically significant positive linear dose-response relationships detected previously for the incidence of thyroid disease (P < 0.0001), chronic liver disease and cirrhosis (P = 0.001), and uterine myoma (P < 0.00001), we also found a significant positive dose response for cataract (P = 0.026), a negative linear dose-response relationship for glaucoma (P = 0.025), and significant quadratic dose-response relationships for hypertension (P = 0.028) and for myocardial infarction among survivors exposed at less than 40 years of age (P = 0.049). Significant radiation effects for calculus of the kidney and ureter were evident for men but not for women (test of heterogeneity by sex: P = 0.007). Accounting for smoking and drinking did not alter the results. Radiation effects for cataract, glaucoma, hypertension, and calculus of the kidney and ureter in men are new findings. These results attest to the need for continued follow-up of the aging A-bomb survivors to fully elucidate the effects of radiation exposure on the occurrence of noncancer diseases.

Adolescent↗
PubMed2002

Prognostic analysis based on the multiple component Weibull and its application to acute myocardial infarction.

This study proposes a new method for a prognostic analysis on the course of diseases. This method aims to separate, among same disease population, several prognostic groups showing different temporal patterns in the course of the disease and evaluate the influence of prognostic factors separately for each group. To do this, we develop a new temporal distribution that we call multiple component Weibull distribution, which is given by a linear combination of Weibull distributions with different shape and scale parameters. This method is applied to the prognostic analysis of cardiac death of acute myocardial infarction (AMI) during hospitalization. The subjects are the first year study population enrolled in the 5-year prospective survey conducted by the Heart Institute, Tokyo Women's University. We separated the prognosis of AMI into two prognostic groups, one with early death of initial failure type and the other with late death of weak abrasion failure type. It was found that a prognostic factor of early death, mostly caused by cardiogenic shock or cardiac failure, was Killip classification, whereas, in the late death, mostly caused by cardiac rupture or perforation, Q type MI and age other than Killip classification were found to be influential prognostic factors.

Age Factors↗
PubMed2004

Temporal trends and spatial distributions of brominated flame retardants in archived fishes from the Great Lakes.

To explore the geographical distribution and temporal trends of polybrominated diphenyl ethers (PBDEs) in the Great Lakes, lake trout from Lakes Superior, Michigan, Huron, and Ontario and walleye from Lake Erie, collected during the period of 1980-2000, were analyzed. The concentrations of fifteen PBDE congeners and one polybrominated biphenyl (PBB-153) were determined in each fish sample. Lake trout from Lakes Michigan and Ontario had the highest sigmaPBDE concentrations during the years investigated. The sigmaPBDE concentrations in fishes from the five lakes increased exponentially with time, doubling every 3-4 years. The relative proportion of BDEs-47, -99, and -100 compared to BDEs-153 and -154 increased significantly as a function of time. Over the period 1980-2000, the concentrations of PBB-153, which was a component of a flame retardant banned in the 1970s, generally remained the same in these Great Lakes fishes, except for lake trout from Lake Huron, where the PBB-153 concentrations decreased significantly, but slowly.

Animals↗
PubMed2001

Atypical radiological images of pulmonary tuberculosis in 192 diabetic patients: a comparative study.

SETTING: Comparative studies of pulmonary tuberculosis images in diabetics have yielded conflicting results. OBJECTIVE: To assess radiological images of pulmonary tuberculosis in a large population of diabetic patients. DESIGN: Radiographs from in-patients admitted with pulmonary tuberculosis and diabetes (TBDM group, n = 192) were reviewed and compared with a control group of patients with pulmonary tuberculosis alone (TB group, n = 130). RESULTS: Both groups had a similar evolution time of tuberculosis (approximately 2 years). Statistical differences were observed as follows: TBDM patients were older (51.3+/-0.9 vs. TB group 44.9+/-1.8 years, mean +/- SEM), and had a decreased frequency of upper (17% vs. 56%), and an increased frequency of lower (19% vs. 7%) and upper + lower (64% vs. 36%) lung field lesions. More TBDM patients developed cavitations (82% vs. 59%) more often in the lower lung fields (29% vs. 3%). More multiple cavities were seen in TBDM patients (25% vs. 2%). TBDM group had a lower total leukocyte count (8836.7+/-219.5 vs. 10013.1+/-345.2 cells/mm3), mainly due to a lower number of non-lymphocyte cells (6815.8+/-221.8 vs. 8095.7+/-321.9 cells/mm3). Multiple logistic regression showed that being a diabetic patient was the most important factor determining lower lung field lesions and cavities. CONCLUSIONS: This study in a large number of diabetics with pulmonary tuberculosis confirmed that their chest X-ray images significantly depart from the typical presentation. Clinicians must keep this in mind to avoid misdiagnosis.

Adult↗
PubMedDate not supplied

A comparison of self-selectivity corrections in economic evaluations and outcomes research.

OBJECTIVE: Two alternative selectivity correction methods have been widely applied in the health economics literature: the sample selection model (SSM) and the multipart model (MPM). The difference between these two approaches results from their initial assumptions about the distribution of error terms. Because the distributional assumptions cannot be theoretically verified, the usefulness of the methods can only be evaluated by real world comparison. This article reviews and empirically tests the two alternative selectivity correction methods to give a reality-based evaluation. METHODS: Using a randomized sample of patients as the "gold standard," the SSM and MPM are applied to a nonrandomized sample of patients with an identical set of dependent and independent variables. By comparing the actual estimates of the two methods, we evaluate the robustness of the two approaches. RESULTS: The results show that neither method is empirically robust in replicating the results of the randomized trial. There is no consistent pattern in the coefficients from either selectivity-correction method for replicating the coefficients in the randomized sample. CONCLUSIONS: Researchers should be cautious in applying these correction methods, and any conclusions based on these approaches may need to be qualified.

Angioplasty, Balloon, Coronary↗
PubMed1998

German medullary thyroid carcinoma/multiple endocrine neoplasia registry. German MTC/MEN Study Group. Medullary Thyroid Carcinoma/Multiple Endocrine Neoplasia Type 2.

INTRODUCTION: A national registry for medullary thyroid carcinoma (MTC) and multiple endocrine neoplasia type 2 (MEN2) was set up to evaluate epidemiological, clinical and prognostic factors of the sporadic and hereditary forms of MTC. PATIENTS AND METHODS: Coded data from 1217 patients with MTC from 57 participating centers in Germany were registered and statistically analyzed. The series included 515 (42%) males (mean age 43.1+/-16.1 years) and 702 (58%) females (mean age 44.4+/-17.6 years), with a mean follow-up of 5.2 years; 865 (71%) exhibited the sporadic form and 352 (29%) the familial form (244 MEN2a, 32 MEN2b, 76 FMTC). The mean age at diagnosis was 49 years for sporadic and 30 years for the familial form. RESULTS: Of the patients, 17% presented at stage I, according to the UICC, and 30%, 45%, and 8% presented at stages II, III, and IV, respectively. There were 12% of patients who died of the disease. The overall adjusted survival rate was 87% at 5 years, and 76% at 10 years. In a univariate analysis, the stage of disease at diagnosis, age, gender, and form were relevant prognostic factors. In a multivariate proportional-hazards analysis, the difference between patients with sporadic and familial disease disappeared. CONCLUSION: As the tumor stage at presentation is the major prognostic factor, early diagnosis and surgical intervention before cervical lymph node metastases appear is necessary to improve survival especially in sporadic cases.

Adult↗
PubMed2003

Horizontal and vertical variabilities of mercury concentration and speciation in sediments of the Gdansk Basin, Southern Baltic Sea.

The mercury compounds introduced to the environment because of anthropogenic activity are accumulated, mainly, in marine sediments. Both distribution of mercury in the Baltic Sea and factors affecting it are remain largely unknown. Due to its complex chemistry and variable conditions in the Baltic Sea bottom sediments, mercury may be reemitted to the overlaying water, and thus to the environment. The aim of this study was twofold. Total mercury contents were measured in sediments of the Gdansk Basin along a Vistula mouth (main source)--Gdansk Deep (deposition area) transect in order to assess spatial distribution of the element. Soft and sandy bottom sediment cores were collected and cut into slices. The mercury measurements consisted of acid digestion followed by CV-AAS determination. A five-step sequential extraction procedure involving measurements of mercury species water soluble, bound to humic substances and insoluble, was employed in order to investigate mercury speciation. On the basis of speciation results stability and remobilisation potential was assessed. The second aim was demonstrating that mercury gradients in vertical profiles of the investigated sediment cores exist. Total mercury contents varied in range from 28 ng/g x dw to 844 ng/g. Mercury associated with organic matter and sulphides, (respectively 39% and 49%) were the dominant species of the element. The results indicated that the river run-off is a source of mercury in the area. Vertical gradients of both total content and speciation of mercury in the soft sediments were attributed to both remobilisation from sediments, and decreasing trend in the anthropogenic load of the element deposited to sediments.

Baltic States↗