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PubMed2000

Tropical pacific forcing of decadal SST variability in the western indian ocean over the past two centuries

A 194-year annual record of skeletal delta(18)O from a coral growing at Malindi, Kenya, preserves a history of sea surface temperature (SST) change that is coherent with instrumental and proxy records of tropical Pacific climate variability over interannual to decadal periods. This variability is superimposed on a warming of as much as 1.3 degrees C since the early 1800s. These results suggest that the tropical Pacific imparts substantial decadal climate variability to the western Indian Ocean and, by implication, may force decadal variability in other regions with strong El Nino-Southern Oscillation teleconnections.

Journal Article↗
PubMed1998

Cerebral Doppler blood flow velocimetry and central hemodynamics in the ovine fetus during hypoxemia-acidemia.

The purpose of this study was to assess the effects of hypocapnic hypoxia, acidemia and the combination of hypoxia/acidemia on blood flow velocity variables in the fetal cerebral circulation. Chronically instrumented fetal sheep were used and the ewes were induced to breathe a hypoxic gas mixture for about 90 min. This caused an initial period of hypoxemia followed by a period of mixed hypoxemia/acidemia. When the ewe was reoxygenated, the fetus experienced a period of normoxic acidemia. The fetal cerebral circulation was assessed by recording Doppler blood flow velocity waveform variables in a cerebral vessel and the umbilical artery, using standard ultrasound equipment. External carotid artery blood flow was maintained during hypoxic and hypoxic/acidotic periods despite a fall in cardiac output. In the cerebral vessel, mean maximum velocity (time-averaged maximum velocity), minimum diastolic velocity and maximum systolic velocity manifested increases during hypoxic and hypoxic-acidotic periods, but pulsatility index did not change due to the effect of reduced heart rate on pulsatility index. Umbilical artery pulsatility index increased in the hypoxic and hypoxic-acidotic periods, despite unchanged mean maximum velocity, minimum diastolic velocity and maximum systolic velocity. With acute hemodynamic changes, the measurement of pulsatility index can yield misleading results. For clinical and experimental research on the fetal cerebral circulation, more attention should be paid to the individual Doppler variables, especially to the mean maximum velocity, than to the pulsatility index alone. Changes in mean maximum velocity recorded from the cerebral artery seem to reflect changes in the cerebral arterial flow.

Acidosis↗
PubMedDate not supplied

Testing sensibility, including touch-pressure, two-point discrimination, point localization, and vibration.

Sensibility is much more than protective sensation, and the examiner needs to consider the various degrees of residual sensibility that influence both diagnosis and prognosis. Towards that end, objective tests of the extent and nature of peripheral nerve involvement should be employed. Objective tests reflect the current condition of sensibility and are not affected by cognitive influences, such as re-education. Most current clinical instruments used for measurement of sensibility fail to meet the criteria of an objective test because they: (1) can be shown to lack necessary sensitivity, and (2) are too variable. As a consequence, regardless of whether these instruments have been used in controlled clinical studies or are in common use, their results will not replicate with repeated testing. Unfortunately, therefore, sensibility changes will potentially go unrecognized in a large number of patients and many will be detected only in the later stages of peripheral nerve abnormality, when possibilities of treatment are less effective. This article discusses sensibility testing from the standpoint of what is known regarding strengths and weaknesses of various tests and sensory modalities, and makes an appeal for clinicians to review the instruments they use critically for sensibility measurement with regard to stimulus control. Clinicians must insist on validity and reliability in their instruments before they have confidence in the data obtained.

Discrimination, Psychological↗
PubMed1993

A comparative study of the debonding strengths of different ceramic brackets, enamel conditioners, and adhesives.

The purpose of this study is to evaluate the use of a sharp-edged debonding instrument on four different ceramic brackets with three different bonding materials and two different enamel conditioning techniques. The effectiveness of the debonding instrument was determined by evaluating the following variables: the amount of force required to debond the bracket, the amount of residual adhesive remaining on the enamel surface, the frequency of bracket failure, and the prevalence of any visible enamel damage. The results indicated that the bracket type, the adhesive, as well as the enamel conditioner, all have an effect on bond strengths when using a sharp-bladed debonding instrument. The following conclusions were derived from the present findings: (1) The mean debonding strength values for the different bracket, adhesive, and enamel conditioner combinations ranged between a low of 40 kg/cm2 and a high of 194 kg/cm2. Most debonding values were between 60 and 115 kg/cm2. (2) A number of bracket, adhesive, and conditioner combinations are considered to have clinically adequate bonding strength and are relatively safe (Table IX). (3) The use of polyacrylic crystal growth enamel conditioner resulted in significantly less adhesive being left on the tooth as compared with the phosphoric acid enamel conditioner.

Acid Etching, Dental↗
PubMedDate not supplied

[Lateral hypothalamus stimulation as a conditioned stimulus for an alimentary instrumental reflex].

Dynamics of the behavioral effects of LH-stimulation which was used as a conditioned stimulus of alimentary reflex, was recorded in dogs during reflex elaboration, extinction and restoration. Before the elaboration, LH-stimulation elicited either an alimentary instrumental relflex, previously established, or a searching, sniffing, licking, orienting reaction, in the majority of cases with variable latencies. Combination of stimulation and achievement of the alimentary instrumental reflex with subsequent reinforcement in short time stabilized the feeding response. Searching, sniffing, orienting reaction disappeared during the elaboration of the conditioned reflex. Elimination of food reinforcement led to extinction of the alimentary reflex to LH-stimulation. In some sessions full abolition of the feeding response was achieved. LH-stimulation inhibitory properties are assumed. The restoration of the alimentary response to LH-stimulation after single reinforcement demonstrated a high plasticity of this structure. The dynamics of the reflex elaboration, extinction and restoration was the same in response both to brain stimulation and to distant stimuli (sound and light). The implicit motivational properties of LH-stimulation were manifested in the ability to activate the feeding behavior in the satiated dogs.

Animals↗
PubMed2002

A study of the mechanical stability of scoliosis constructs using variable numbers of sublaminar wires.

Sublaminar wiring with posterior instrumentation is one of the methods used when long fusions involving 10-12 thoracolumbar levels are required. Classically, wires are used at every consecutive level to make the construct as rigid as possible, although complications like dural tears, cerebrospinal fluid leak, and neurological deficit have been reported during their passage. We compared the mechanical stability under torsional strain of five specimens of each of three construct designs, by static and fatigue testing, using an electro-servo-hydraulic testing machine. In construct A, a contoured Hartshill rectangle was used from T2 to L2, with sublaminar wires passed at every level. In construct B, the Hartshill rectangle was wired to the spine at every alternate level. In construct C, every alternate level was wired except at the proximal end, where two consecutive levels were wired. Industrially fabricated spine models were used to prepare these constructs. The intervertebral motion within the construct was measured using the Fastrak magnetic field sensor device. On static testing, no statistically significant difference was found in the rotational displacement of the three construct designs. On fatigue testing, all samples of construct B consistently failed, with breakage of the wire at the most proximal level on the left side. But on adding additional wires to the next level (construct C), all five samples withstood fatigue testing at 300 N load to three million cycles. We conclude that wiring alternate levels instead of every level does not compromise the stability of the construct, provided that the most proximal two levels are consecutively wired. This practice would minimise the risk of dural tears and cord damage during wire passage and reduce surgical time, not to mention the economic benefits.

Biomechanical Phenomena↗
PubMed1985

Effect of manipulative variables on the accuracy of crown wax patterns.

An instrument was developed to carve wax patterns in a reproducible manner. The methods of wax application to the die and wax removal during carving were similar to routine laboratory procedures. The wax patterns were invested in stone with the dies on which they were prepared, and sectioned to allow the determination of their adaptation on sectioned samples. Shrinkage of wax patterns on dies was found to create a marginal gap at shoulders and bevels. Further shrinkage observed after removal from the die was attributed to relaxation of elastic stresses in the wax. Carving of bevels improved adaptation to the die for samples with large gaps at the shoulder. This improved adaptation can be attributed to plastic deformation in the wax bevel. Remodeling of pattern margins was found to improve adaptation to the die, especially if carried out after the pattern was removed and replaced on the die. Remodeling the margin should involve heating with a spatula of a narrow band of wax around the margin up to the axial die wall over the entire shoulder width.

Chemical Phenomena↗
PubMed1990

Action and emotion in everyday life.

This study of naturally occurring behaviour employed a "beeper technique" to investigate the actions carried out by 152 subjects in eight different groups, viz. adult students, employed students who were also parents, unemployed, art students, doctoral students, alcoholics, retired people and a control group. Actions were sampled for seven subsequent days, five times per day between 8 a.m. and 10 p.m. at randomly selected occasions. Each action was rated on a number of variables, shortly after it was sampled (median delay approximately 10 min). Some of the findings were: Time allocation corresponded well with national estimates. Being under situational control was highly aversive. Instrumental and consummatory orientations correlated positively. The background variables were, on the whole, only rather weakly related to action ratings, but it was found that women and retired persons tended to report a higher level of well-being.

Activities of Daily Living↗
PubMed2000

The effects of childhood residence in Japan and testing language on cognitive performance in late life among Japanese American men in Hawaii.

OBJECTIVES: To examine the association of years spent in Japan during childhood with cognitive test performance in late life among Japanese American men, and to assess the influence of the language used for testing on this association. DESIGN: A cross-sectional study. SETTING/PARTICIPANTS: A total of 3734 Japanese American men, aged 71-93 years, who were first- or second-generation migrants and living on Oahu Island, Hawaii. MEASUREMENTS: The outcome variable was cognitive test performance assessed using the Cognitive Abilities Screening Instrument (CASI), which was developed for cross-cultural studies of cognitive impairment. The explanatory variable of main interest was the number of years spent in Japan during school-age childhood years (ages 6-17). The associations of CASI scores with childhood years in Japan was evaluated using a stepwise multiple linear regression model in which a total of 40 potential confounders were included as covariates. RESULTS: In the total sample, there was an inverse association between CASI scores and middle childhood years in Japan. This association remained significant after controlling for age, education, socioeconomic status, traditional Japanese food consumption, pulmonary function, apolipoprotein E4, proficiency in speaking Japanese, and other possible confounders. When data were analyzed separately for subgroups according to the language preferred at testing (English or Japanese), associations between childhood years in Japan and CASI scores were in opposite directions negative for the group tested in English and positive for the group tested in Japanese. The interaction between the testing language and childhood years in Japan was statistically significant. CONCLUSIONS: There was an inverse association between years spent in Japan during school-age years of childhood and cognitive test performance in late life. This association could not be accounted for by age, education, or other confounding factors. However, this finding was not observed in participants who preferred being tested in Japanese. To assess cognitive test performance in older people, it is of prime importance to use the most optimal language for testing, usually the subject's native language.

Adolescent↗
PubMed2006

Predicting long-term independency in activities of daily living after middle cerebral artery stroke: does information from MRI have added predictive value compared with clinical information?

BACKGROUND AND PURPOSE: To investigate whether neuroimaging information has added predictive value compared with clinical information for independency in activities of daily living (ADL) 1 year after stroke. METHODS: Seventy-five first-ever middle cerebral artery stroke survivors were evaluated in logistic regression analyses. Model 1 was derived on the basis of clinical variables; for model 2, neuroimaging variables were added to model 1. Independent variables were stroke severity (National Institutes of Health Stroke Scale), consciousness (Glasgow Coma Scale), urinary continence, demographic variables (age, gender, relationship, educational level), hospital of admission, and clinical instruments: sitting balance (trunk control test), motor functioning (Motricity Index), and ADL (Barthel Index). Neuroimaging variables, determined on conventional MRI scans, included: number of days to scanning, lesion volume, lesion localization (cortex/subcortex), hemisphere, and the presence of white matter lesions. ADL independency was defined as 19 and 20 points on Barthel Index. Differences in accuracy of prediction of ADL independence between models 1 and 2 were analyzed by comparing areas under the curve (AUC) in a receiver operating characteristic analysis. RESULTS: Model 1 contained as significant predictors: age and ADL (AUC 0.84), correctly predicting 77%. In model 2, number of days to scanning, hemisphere, and lesion volume were added to model 1, increasing the AUC from 0.84 to 0.87, accurately predicting 83% of the surviving patients. CONCLUSIONS: Clinical variables in the second week after stroke are good predictors for independency in ADL 1 year after stroke. Neuroimaging variables on conventional MRI scans do not have added value in long-term prediction of ADL.

Activities of Daily Living↗
PubMed2002

Rapid antibiotic delivery and appropriate antibiotic selection reduce length of hospital stay of patients with community-acquired pneumonia: link between quality of care and resource utilization.

OBJECTIVES: To measure quality-of-care variables relevant to the treatment of community-acquired pneumonia and to determine their relative contribution to variation in length of hospital stay (LOS). METHODS: One hundred cases of pneumonia requiring hospitalization from each of 7 institutions (2 community and 5 university teaching hospitals) were randomly selected (total sample, 700 cases). Demographic and clinical variables were abstracted using a standardized data instrument. Three quality-of-care measures were analyzed: (1) site of initial antibiotic treatment (emergency department vs floor), (2) door-to-needle time, and (3) appropriateness of antibiotic selection. Appropriate antibiotic selection was defined by the 1998 Infectious Disease Society of America guidelines for the treatment of hospitalized pneumonia cases. Regression modeling was used to determine associations between LOS and our quality-of-care (process) variables. RESULTS: The mean +/- SD LOS for this sample was 7.0 +/- 4.1 days. Prolonged LOS, defined as greater than or equal to the 75th percentile of the LOS distribution, was the dependent variable in our regression analysis and was greater than or equal to 9.0 days. After clinical and demographic variables were adjusted for, logistic regression modeling revealed that all 3 quality-of-care measures were associated with prolonged LOS: (1) initial antibiotic treatment in the emergency department (odds ratio [OR], 0.31; 95% confidence interval [CI], 0.19-0.48); (2) appropriate antibiotic selection (OR, 0.55; 95% CI, 0.35-0.88); and (3) door-to-needle time (OR, 1.75 per 8 hours; 95% CI, 1.34-2.29). In a secondary analysis, we examined the clinical and demographic characteristics of the patients who were treated more rapidly in the emergency department compared with those who were treated on the inpatient floor. No clinically meaningful differences were observed between these groups. CONCLUSIONS: Unlike clinical and demographic variables, process-of-care variables are modifiable and amenable to quality improvement. We observed that rapid antibiotic initiation and appropriate antibiotic selection in the emergency department have a statistically significant association with shorter LOS. These findings suggest quality improvement targeted at these processes of care may improve resource utilization and reduce LOS for patients with community-acquired pneumonia.

Aged↗
PubMedDate not supplied

[Chronic diseases and functional limitation in older adults: a comparative study in seven cities of Latin America and the Caribbean].

OBJECTIVE: To identify the relationship between selected chronic diseases and the presence of disability in inhabitants 60 years old or older in seven cities of Latin America and the Caribbean. METHODS: In 2000 and 2001 a descriptive cross-sectional study was conducted with a sample of 10 891 persons 60 or older in seven cities: Bridgetown, Barbados; Buenos Aires, Argentina; Havana, Cuba; Mexico City, Mexico; Montevideo, Uruguay; Santiago, Chile; and São Paulo, Brazil. This research was part of the Salud, Bienestar y Envejecimiento (Health, Well-Being, and Aging) project (known as the "SABE project"). The dependent variables in the study were difficulty in performing basic activities of daily living, and difficulty in performing instrumental activities of daily living. Compiled from self-reports, the independent variables were: age, sex, educational level, living alone or with other person(s), self-assessed health, and the presence or not of hypertension, diabetes mellitus, cancer, chronic obstructive pulmonary disease, ischemic heart disease, cerebrovascular diseases, and osteoarthritis. The presence of depression and cognitive impairment in the participants was evaluated, and body mass index was also calculated. To compare the degree of influence of the different variables on disability, a standardized coefficient for each association was calculated. RESULTS: In the seven cities studied, the variables that showed a direct association with difficulty in carrying out basic activities of daily living and instrumental activities of daily living were: suffering from a higher number of noncommunicable diseases, from cerebrovascular diseases, from osteoarthritis, or from depression; being older; being female; rating one's own health as bad; and experiencing cognitive impairment. In general the strongest associations were between difficulty in carrying out instrumental activities of daily living and depression, being older, reporting one's health as bad, and the presence of cerebrovascular diseases, osteoarthritis, or cognitive impairment. CONCLUSIONS: Our research provides the first systematized description of the associations between disability and chronic noncommunicable diseases in older adults in Latin America and the Caribbean. Difficulties that older adults have in carrying out instrumental activities of daily living are the first ones to appear. Therefore, follow-up mechanisms should be established that make possible the early detection of this type of disability.

Aged↗
PubMed2001

The clinical relevance of the citrate effect on International Normalized Ratio determinations depends on the reagent and instrument combination used.

Multiple studies have shown that the two different citrate concentrations in common use as the anticoagulant in blood collection for haemostasis assays can affect the results obtained with the prothrombin time assay. It is clear from the literature that there is considerable variability in the results obtained using different instrument-reagents combinations, but the clinical relevance of these differences is unclear. Most of the studies have used an optical system for end-point detection. This study reports on the citrate sensitivity using mechanical end-point detection. Using two different reagents, one previously shown to be citrate sensitive on optical systems (Neoplastin CI plus) and a citrate-insensitive reagent (Neoplastin CI), we demonstrate that the effect of using different citrate concentrations (0.105 or 0.129 mol/l) has statistically significant but clinically irrelevant effects on the International Normalized Ratio using a mechanical instrument (STA)-reagent combination (mean percentage difference in results, 1.9 and 3.8% respectively). This demonstrates that the citrate effect is both instrument type and reagent dependent. Every reagent and instrument combination needs to be tested to see whether any citrate effect exists. In a secondary study, it was shown that the international reference rabbit thromboplastin (CRM 149(s)) was not citrate-concentration sensitive.

Animals↗
PubMed2002

Alcohol consumption is associated with improved health-related quality of life in head and neck cancer patients.

The study aim was to investigate the relationship between alcohol consumption and health-related quality of life (HRQL) in post-therapeutic head and neck cancer patients. A cross-sectional study design was used with a sample of 191 subjects. Data were collected through interview and chart review. Alcohol consumption was evaluated through the dichotomous response to the question "During the past month have you drunk alcohol on one or more occasions?" HRQL was evaluated through the EORTC QLQ-C30 and H&N35 instruments. Data were also collected concerning sociodemographic and clinical variables. Multivariate regression was used to evaluate the hypothesized association. Of 28 domains comprising the EORTC QLQ-C30 and H&N35 instruments, eight were significantly associated with alcohol consumption, while 19 of the 20 remaining domains showed a tendency towards an association. Alcohol drinking was associated with significantly better physical and role functioning, and better global HRQL, plus less fatigue, pain, problems swallowing, dry mouth and feelings of illness. This suggests that, while the study findings are limited by its design and the sample bias, despite alcohol's role as an aetiological factor, it may be reasonable to drink a little as one recovers from head and neck cancer.

Adult↗
PubMed1995

Total body electrical conductivity measurements: an evaluation of current instrumentation for infants.

Quantitation of the body's fat and learn masses is an important component of nutritional assessment. Such measurements, however, are difficult to conduct routinely in infants due to the numerous limitations of traditional methods. The application of total body electrical conductivity measurements for quantitating fat-free mass (FFM) overcomes many of these limitations. The instruments required to perform these measurements in pediatric patients (HP-2) have recently become commercially available, but their measurement performance has not been evaluated. In these studies, we compared the precision, day-to-day variability, and magnetic field profile of three HP-2 instruments. We also derived a new calibration equation that relates the FFM to the total body electrical conductivity measurement in piglets, and compared it with an equation (provided currently by the manufacturer) derived on a prototype instrument. The performance of the instruments was generally similar, although a significant difference in the magnetic field of one instrument was identified. The coefficient of variation of inanimate phantom measurements varied from +/- 0.2 to +/- 0.5%, and the day-to-day variability was generally similar. Such measurement error is significant (+/- 0.035 to +/- 0.078 kg FFM) for small subjects. The new calibration equation was similar to the original equation; therefore, all the data were pooled to generate a new equation that is linear at least to 10 kg. Thus, the HP-2 total body electrical conductivity instruments, which can be safely and easily used to measure FFM and fat in infants through 1 y of age, proved to be reliable and precise, and results obtained from different instruments can be confidently compared.

Adipose Tissue↗
PubMed1997

Office spirometry: equipment selection and training of staff in the private practice setting.

Spirometry is a basic pulmonary function test that is widely used for the detection of airflow limitation. Its use will continue to grow in the medical office setting because it is useful for both diagnostic and monitoring purposes. Additionally, the assessment of airflow reversibility is a quick, safe, and useful adjunct to baseline spirometry. Many manufacturers offer various models and types of spirometers. Before purchasing, determine the needs and characteristics of the office and its staff, and then choose an appropriate device. There is no "holy grail" for selecting what instrument is best for a specific office. Rather, it requires time and effort to make a good choice. Carefully assess the instrument before purchase and, ideally, compare several instruments. Once an instrument is purchased and it arrives, carefully validate it before reporting results. Proper training of the technicians who perform the testing is perhaps the most important factor in obtaining good spirometric testing. After adequate training, it is also important to have continued competency assessments, periodic inservices, and careful review of test results. The ATS and American Association for Respiratory Care (AARC) published extensive guidelines on the performance of spirometry. These recommendations should be followed to ensure quality and reduce interlaboratory variability. Patients should be properly prepared, the instrumentation properly calibrated, and the test conducted so that there is a good start, adequate exhalation time, satisfactory end-of-test, and good reproducibility between trials.

Age Factors↗
PubMed2005

Social cognitive theory variables associated with physical activity among high school students.

The purpose of this study was to describe the relationships between Social Cognitive Theory (SCT) variables and frequency of moderate-vigorous physical activity in a sample of high school students. Days of moderate and vigorous physical activity were assessed using a previously validated one-day recall instrument administered on seven consecutive days. The SCT variables tested were: self-regulation, social situation, social outcome expectations, physical appearance outcome expectations, general health outcome expectations, negative outcome expectations, self-efficacy for ability, and self-efficacy for barriers. The SCT variables studied are potentially modifiable via educational interventions. Results revealed that 15 % of the subjects reported 3 or more days of physical activity. Four of the SCT were retained in the regression model accounting for 31 % of the variance in days or moderate-vigorous physical activity. SCT is useful for understanding frequency of moderate-vigorous physical activity among adolescents.

Adolescent↗
PubMed1998

Preoperative evaluation of activity and function in patients with paralytic scoliosis.

Preoperative evaluation of patients with paralytic scoliosis should take into account the consequences of surgery on the every day life of the patient. However, the parameters that are customarily used in these operations relate only to very narrow measures such as the angle of scoliosis or kyphosis. The aim of this study was to introduce a set of instruments appropriate for measuring both function and activities in paralytic scoliosis patients. The study took as its starting point the WHO International Classification of Impairments, Disabilities and Handicaps (ICIDH), in which an activity is described at the level of the individual and function at the level of the organ. A consecutive series of 100 paralytic scoliosis patients with 18 different diagnoses were evaluated preoperatively with a set of instruments that had been specially developed at Linköping hospital, in which the variables are classified according to the system used in the ICIDH. The set of instruments included general information and evaluation of activities and function--sitting, balance, weight distribution to sitting surface, angle of scoliosis, reaching, pain estimation, activities of daily living (ADL) Barthel and ADL Klein and Bell, care given, time spent resting, and seating supports). The results showed that patients with paralytic scoliosis constitute a heterogeneous group in activities and function. Even when the patients were grouped into four subgroups according to the Scoliosis Research Society Classification, they remained very heterogeneous. However, reaching, Klein and Bell Activities of Daily Living and pain could only evaluate patients who could understand verbal instructions. In those who could not, assessment relied more heavily on measures of function and level of dependence. It was concluded that the choice of assessment must be guided by the patient's ability to understand verbal instructions irrespective of his/her disorder. It is important to use the three levels--impairments, disabilities and handicaps-- in order to focus on the different outcomes in the two groups with respect to the patient's total situation.

Activities of Daily Living↗