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S Lord

Publications and source records attributed to S Lord.

At least 19 recordsLinked to original sources
PubMed1997

Test-retest reliability of a battery of sensory motor and physiological measures of aging.

We report test-retest reliabilities for a battery of tests (vision, hearing, vibration sense, proprioception, forced expiratory volume, blood pressure, grip strength, and sway) shown previously to predict functional age. Fifty women aged 60 to 86 were retested on the battery after 3 months. All tests except proprioception and blood pressure had reliabilities between .70 and .94. We conclude that the battery provides reliable measures of sensory, motor, and physiological variables which may be used as markers of biological aging in psychological research.

Aged↗
PubMed1996

Schools, families, and early adolescents: what are we doing wrong and what can we do instead?

Although most individuals pass through adolescence without excessively high levels of "storm and stress," many individuals experience difficulty during this period. Why? Is there something unique about this developmental period that puts individuals at greater risk for difficulty? This paper focuses on these questions and advances the hypothesis that some of the "negative" psychological and behavioral changes associated with adolescent development result from a mismatch between the needs of developing adolescents and their experiences at school and at home. It provides theoretical and empirical examples of how this mismatch develops, how it is linked to negative age-related changes in early adolescents' motivation, self-perceptions, self-evaluations, and psychological competence, and how we could provide more developmentally appropriate social environments, particularly at school.

Adolescent↗
PubMed1993

Prediction of osteoporotic fractures by postural instability and bone density.

OBJECTIVE: To investigate the utility of risk factors such as bone mineral density, lifestyle, and postural stability in the prediction of osteoporotic fractures. DESIGN: Longitudinal, epidemiological, and population based survey. SETTING: City of Dubbo, New South Wales. SUBJECTS: All residents of Dubbo aged > or = 60 on 1 January 1989. MAIN OUTCOME MEASURE: Incidence of fracture for individual subjects. RESULTS: The overall incidence of atraumatic fractures in men and women was 1.9% and 3.1% per annum respectively. The predominant sites of fracture were hip (18.9%), distal radius (18.5%), ribs and humerus (11.9% in each case), and ankle and foot (9.1% and 6.6% respectively). Major predictors of fractures in men and women were femoral neck bone mineral density, body sway, and quadriceps strength. Age, years since menopause, height, weight, and lifestyle factors were also correlated with bone mineral density and body sway and hence were indirect risk factors for fracture. Discriminant function analysis correctly identified 96% and 93% (sensitivities 88% and 81%) of men and women, respectively, who subsequently developed atraumatic fractures. Predictions based on this model indicated that a woman with a bone mineral density in the lowest quartile in the hip together with high body sway had a 8.4% probability of fracture per annum. This represented an almost 14-fold increase in risk of fracture compared with a woman in the highest bone mineral density quartile with low postural sway. An individual with all three predictors in the "highest risk" quartile had a 13.1% risk of fracture per annum. CONCLUSIONS: Bone mineral density, body sway, and muscle strength are independent and powerful synergistic predictors of fracture incidence.

Aged↗
PubMed1993

Primary aging, secondary aging, and intelligence.

The distinction between primary aging, representing innate maturational processes, and secondary aging, representing the effects of environment and disease (Busse, 1969), was used to develop a model for the assessment of factors that are associated with age-related individual differences in intelligence. Intelligence was measured by performance on a number of tests that measure cognitive abilities known to decline with age. In a hierarchical multiple regression analysis, primary aging and education but not health explained a significant portion of the variance in fluid intelligence. Chronological age had a residual effect over and above that of primary and secondary aging, indicating that there was remaining age-associated variance unaccounted for in the proposed model. The results suggest that the model of primary and secondary aging is a valid means of operationalizing chronological age.

Activities of Daily Living↗
PubMed1993

False-positive rates of cervical zygapophysial joint blocks.

OBJECTIVE: To determine the false-positive rate of anesthetic blocks of the medial branches of the cervical dorsal rami in the diagnosis of cervical zygapophysial joint pain. DESIGN: Comparison between single diagnostic blocks, and a criterion standard of double-blind, controlled, differential anesthetic blocks. SETTING: Tertiary referral center. PATIENTS: The first 55 consecutive patients with neck pain for > 3 months after and attributable to a motor vehicle accident, and who had completed a second diagnostic block after an initial positive response. A total of 60 joints was studied, with five patients providing two joints each. The mean age was 41 years; 61% were female. METHODS: Each patient had been investigated with radiologically controlled blocks of the medial branches of the cervical dorsal rami to anesthetize the target cervical zygapophysial joint. The initial block was performed using either 0.5% bupivacaine or 2% lignocaine, randomly selected. The duration of pain relief was assessed in a double-blind fashion. The procedure was repeated with the complementary anesthetic. Only patients experiencing a longer period of pain relief from bupivacaine were considered to have true-positive responses. RESULTS: The second block failed to relieve pain in two of the tested joints. In a further 14 joints, the control blocks relieved pain, but the patient failed to correctly discriminate the longer acting anesthetic. The remaining 44 joints met the criteria for true-positive responses. The false-positive rate of single blocks was 16 of 60 or 27% (95% confidence interval 15%, 38%). CONCLUSIONS: Uncontrolled diagnostic blocks are compromised by a significant false-positive rate that seriously detracts from the specificity of the test.

Accidents, Traffic↗
PubMed1991

Night-to-night variability of disturbed breathing during sleep in an elderly community sample.

Night-to-night variability of breathing and oxygenation during sleep was examined with portable monitoring equipment in 30 residents of a retirement village. Subjects had a variety of health problems as might be expected in the elderly, but all were living independently in self-contained units. None had clinical features to suggest obstructive sleep apnea. Two pairs of consecutive nights were studied, separated by 4-6 months. Satisfactory recordings on all four nights were obtained in 15 subjects, and in these subjects variability of measurements was examined across nights 1-4 using the kappa (K) statistic. There was low but significant agreement in estimated total sleep time (K = 0.23, p less than 0.01) and estimated wakefulness after sleep onset (K = 0.18, p less than 0.05) as assessed with a wrist actigraph. Good agreement was found among measures of disturbed breathing during sleep whether expressed in terms of numbers of events [respiratory disturbance index (RDI), K = 0.62, p less than 0.0001], their duration (event minutes, K = 0.53, p less than 0.0001), or associated disturbance of oxygenation (% cumulative time less than 90% SaO2, K = 0.50, p less than 0.001, n = 9). Twenty-eight subjects had at least two nights' satisfactory recordings. Although some of these individuals showed considerable variation in RDI, this had little overall effect on classification of them into normal (RDI less than or equal to 15) and abnormal groups. The accuracy of the first night's recording in predicting classification derived from recording on three or four nights was 83%.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1990

The genomic organization of platelet glycoprotein IIIa.

The platelet membrane glycoprotein (GP) IIb/IIIa complex, a member of the integrin family of adhesive receptors involved in cell-cell and cell-matrix interactions, contains binding sites for fibrinogen, von Willebrand factor, fibronectin, and vitronectin. Absence or defects of this receptor result in the platelet bleeding disorder Glanzmann's thrombasthenia. In this report, we describe the isolation of genomic DNA coding for the entire mature GPIIIa protein. Mature GPIIIa is encoded by 14 exons which range in length from 90 to 3618 base pairs, which are contained within an approximately 46-kilobase (kb) stretch of genomic DNA on chromosome 17. All of the exon/intron junctions were found to conform to the consensus splice donor and acceptor sequences. The coding region of the GPIIIa gene is identical with the previously described cDNA sequence except for three silent substitutions. One substitution creates a TaqI site which may be the site of a known GPIIIa polymorphism. A second substitution eliminates a SmaI site. Aside from the start of the first exon described, which begins at the second base of the first codon of the mature protein, there is no correlation between the organization of the exons in this gene and proposed functional domains of the protein based on analysis of the primary amino acid sequence. The less frequently used polyadenylation signal AAATTAAA was present at the 3'-end of the major RNA transcript. Recently, an alternatively processed GPIIIa transcript has been described. We demonstrate that this transcript results from nonsplicing of the final intron. The description of the GPIIIa gene organization should be of importance in understanding the evolution of the integrin family of receptors and should be useful in the molecular biology analysis of thrombasthenic patients who have a defect in the GPIIIa gene.

Amino Acid Sequence↗
PubMed1989

Interrater reliability of computer-assisted scoring of breathing during sleep.

Twenty-six records of sleep and breathing obtained with a portable monitoring system from elderly subjects were scored by three raters with computer assistance to examine interrater reliability of scoring. Raters were a medical student, a nurse practitioner, and a family physician, all of whom had at least one month's experience with the equipment. Agreement among raters was measured with the unweighted kappa statistic. Significant agreement was observed for all variables, although agreement was better for variables describing breathing (range of kappa 0.71-0.87) than for those describing sleep (range of kappa 0.34-0.57). Complete agreement among the three raters on diagnostic classification occurred in 17 cases. In the remaining 9 cases, 2 raters agreed, whereas the third differed by not more than one category for type of disturbance (e.g., normal versus hypopnea, hypopnea versus apnea) or severity (e.g., mild versus moderate). There was only one disagreement among raters for the 9 subjects with severe respiratory disturbance. We conclude that interrater reliability of identifying and characterizing breathing disturbance during sleep as recorded by portable monitoring is high among trained raters using computer assistance.

Aged↗
PubMed1988

Breath methane and large bowel cancer risk in contrasting African populations.

Breath methane has been measured in 1016 people from four populations resident in Southern Africa which experience widely different risks of bowel cancer and other colonic diseases. Highly significant differences in the proportion of subjects with detectable methane in breath were found; % producers--rural black 84, urban black 72, white 52, Indian 41 (chi 2 121 p less than 0.001 3 df). There was a slight preponderance of female producers over male (female producers 63%, males 57%) and an age trend with fewer producers in the older age groups in the urban blacks and Indians, these comparisons being significant when tested by stepwise logistic regression analysis. Bowel cancer risk, determined from a variety of sources, was lowest in rural blacks, greatest in whites, with intermediate rates for urban blacks and Indians. Methane production in the human colon shows significant interethnic differences but which bear no relation to bowel cancer risk in these populations.

Adolescent↗
PubMed1985

A family study of schizophrenic and normal control probands: implications for the spectrum concept of schizophrenia.

Morbidity risks for mental illness were determined in 750 first-degree relatives of chronic schizophrenic and normal control probands. Psychiatric disorders that were more frequent in relatives of schizophrenic probands than in relatives of normal control probands were chronic schizophrenia (5.8% versus 0.6%), schizotypal personality disorder (definite, 14.6% versus 2.1%; probable, 12.1% versus 6.5%), and paranoid personality disorder (7.3% versus 2.3%). The data suggest that schizotypal and paranoid personality disorders are genetically related to schizophrenia. The implications for schizophrenia research are discussed.

Adolescent↗
PubMed1985

Familial transmission of schizotypal and borderline personality disorders.

The authors determined the risk for psychiatric disorders in the first-degree relatives of 36 probands with schizotypal personality disorder (13 definite, 23 probable), 17 probands with borderline personality disorder (two definite, 15 probable), and 90 normal control probands. The relatives of probands with schizotypal personality disorder without a concurrent diagnosis of borderline personality disorder had a significantly greater risk for schizotypal personality disorder than the relatives of normal control probands, borderline probands, or schizotypal probands with coexisting borderline personality disorder. The relatives of borderline probands had a significantly greater risk for definite and probable borderline personality disorder than the relatives of normal control probands.

Adult↗
PubMed1983

Cis-platinum ototoxicity: clinical experience and temporal bone histopathology.

A clinical and pathologic study of cis-platinum ototoxicity was performed. Twenty-four patients treated with cis-platinum for head and neck cancer were studied prospectively. Post cis-platinum hearing losses were subclinical, detected in 25% of patients, isolated to 4 and 8 kHz, and did not exceed 25 dB at any frequency. Temporal bones from a 9-year-old with frontal lobe astrocytoma and with cis-platinum ototoxicity were studied with routine and special techniques to elucidate oto and neurotoxicity. Degenerative changes in the outer hair cells in the lower turns of the cochlea, in the spiral ganglion, and cochlear nerve were the most striking findings.

Adult↗
PubMedDate not supplied

Preseason hamstring muscle weakness associated with hamstring muscle injury in Australian footballers.

Hamstring muscle strain is the most prevalent injury in Australian Rules Football, accounting for 16% of playing time missed as a result of injury. Thirty-seven professional footballers from an Australian Football League team had preseason measurements of hamstring and quadriceps muscle concentric peak torque at 60, 180, and 300 deg/sec measured on a Cybex 340 dynamometer. Players were studied prospectively throughout the 1995 season. During that time, six players sustained clinically diagnosed hamstring muscle injuries that caused them to miss match-playing time. The injured hamstring muscles were all weaker than in the opposite leg in absolute values and hamstring-to-quadriceps muscle ratios. According to our t-test results, hamstring muscle injury was significantly associated with a low hamstring-to-quadriceps muscle peak torque ratio at 60 deg/sec on the injured side and a low hamstring muscle side-to-side peak torque ratio at 60 deg/sec. Flexibility (as measured by the sit-and-reach test) did not correlate with injury. Discriminant-function analysis using the two significant ratio variables resulted in a canonical correlation with injury of 0.4594 and correctly classified legs into injury groups with 77.4% success. These results indicate that preseason isokinetic testing of professional Australian Rules footballers can identify players at risk of developing hamstring muscle strains.

Adult↗