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Biomedical subjects

J Chandler

Publications and source records attributed to J Chandler.

At least 55 records · Page 3Linked to original sources
PubMed1996

Cytotoxicity of KDEL-terminated ricin toxins correlates with distribution of the KDEL receptor in the Golgi.

DNAs encoding ricin toxin A chain (RTA), with or without a C-terminal endoplasmic reticulum retention signal KDEL, were subcloned into pGEX2T bacterial expression plasmid. After transformation of JM105 E. coli cells and induction with isopropylthio-beta-galactoside (IPTG), fusion proteins were bound to an immobilized glutathione matrix and recombinant ricin A chains released with thrombin. Both recombinant wild-type RTA and RTA with KDEL had immunological reactivity and catalytic activity indistinguishable from plant RTA. The bacterial RTA products reassociated with plant ricin B chain (RTB) similarly to plant RTA. Cell cytotoxicities were measured on seven cell lines for each A-chain and heterodimer. Although KDEL sequences enhanced cytotoxicity in most cases, significant variability was observed. In each case, addition of KDEL enhanced A-chain cytotoxicity more than holotoxin cytotoxicity. Three cell lines showed reduced KDEL enhancement of both RTA and ricin cytotoxicity. The concentration of KDEL receptor was examined on each cell line by immunofluorescence microscopy with an antireceptor monoclonal antibody. Differences in sensitivity to KDEL-containing toxins correlated with altered distribution of KDEL receptor between endoplasmic reticulum (ER) and Golgi compartments.

Amino Acid Sequence↗
PubMed1995

Sensory interaction and descriptions of fabric hand.

82 subjects who viewed and felt fabrics (sensory interaction group) used different categories of terms to describe fabric hand than did 38 subjects who only felt the fabrics. Therefore, the methods used to measure fabric hand that isolate the senses may not accurately assess the way in which subjects describe fabric hand in nonlaboratory settings.

Adult↗
PubMed1994

Predicting falls: the role of mobility and nonphysical factors.

OBJECTIVE: Our purpose was to test a four-domain predictive model of recurrent falls developed for this study. In this model, limited mobility is considered a necessary but not sufficient element in risk of recurrent falls. Three other domains, attitudinal, social, and environmental, are proposed to influence fall risk only in persons with impaired mobility. DESIGN: Prospective cohort study. SETTING: Veterans Affairs Ambulatory Care Service serving rural and urban central North Carolina. SUBJECTS: Male Veterans aged 70 or older (n = 306) were monitored prospectively for falls. At baseline, 159 screened as high-risk mobility status and 147 as low-risk mobility status. MEASUREMENTS: The primary outcome was recurrent falls. The mobility screen used for risk assignment defined immobile as unable to sit without support for 60 seconds, mobile and stable as meeting criteria for normal ambulation and stair climbing, and mobile but unstable as those who met neither of the above criteria. The high-risk subjects were further assessed in their homes for mobility in more detail, attitude toward risk, social supports, and environmental status. Other data included demographics, functional status, diagnoses, and medications. RESULTS: Recurrent falls occurred in 37 (23.3%) high-risk subjects and seven (4.8%) low-risk subjects (relative risk = 4.8, confidence interval 2.5 to 9.6, P < 0.001). Within the high-risk group, the probability of recurrent falls was significantly affected by degree of impaired mobility (P < 0.001), attitude toward risk (P = 0.005), and environment score (P = 0.03). CONCLUSIONS: A simple mobility screen can identify elders at increased risk for recurrent falls. Risk within this group is further modified by risk-taking behavior and environment.

Accidental Falls↗
PubMed1993

Magnetic resonance imaging morphometric analysis of cerebral volume loss in human immunodeficiency virus infection. The HNRC Group.

Magnetic resonance imaging was used to compare male subjects seropositive for antibody to human immunodeficiency virus type 1 (HIV positive), with and without medical symptoms, with two groups of men who were seronegative (HIV negative). The control subjects included men at high risk for exposure to HIV-1 and those at low risk. None of the HIV-positive subjects met criteria for HIV-associated dementia or had detectable opportunistic brain disease. Quantitative image-analytic techniques were used to estimate volumes of ventricular and cortical cerebrospinal fluid, cerebral white matter, and cortical and subcortical gray matter structures. Relative to low-risk group control subjects and asymptomatic HIV-positive subjects, nondemented but medically symptomatic HIV-positive subjects showed significant increases in cerebrospinal fluid, reduced volume of cerebral white matter, and reduced cerebral gray matter volumes. Unexpectedly, however, some cerebrospinal fluid increases and gray matter volume decreases were present in the seronegative high-risk control subjects as well.

Adult↗
PubMed1993

Metabolic regulation of alpha-amylase gene expression in transgenic cell cultures of rice (Oryza sativa L.).

Expression of two genes in the alpha-amylase gene family is controlled by metabolic regulation in rice cultured cells. The levels of RAmy3D and RAmy3E mRNAs in rice cultured cells are inversely related to the concentration of sugar in the culture medium. Other genes in the rice alpha-amylase gene family have little or no expression in cultured cells; these expression levels are not controlled by metabolic regulation. A RAmy3D promoter/GUS gene fusion was metabolically regulated in the transgenic rice cell line 3DG, just as the endogenous RAmy3D gene is regulated. An assay of GUS enzyme activity in 3DG cells demonstrated that RAmy3D/GUS expression is repressed when sugar is present in the culture medium and induced when sugar is removed from the medium. The 942 bp fragment of the RAmy3D promoter that was linked to the coding region of the GUS reporter gene thus contains all of the regulatory sequences necessary for metabolic regulation of the gene.

Base Sequence↗
PubMed1993

How do physiological components of balance affect mobility in elderly men?

The purpose of this study was to assess the relationship between physiological components of balance and mobility in elderly men without significant disease. Our a priori hypothesis was that physical function is influenced more by accumulated modest impairments than by a single deficit. We examined 39 ambulatory men (> 69 years). Subjects were classified functionally as high, intermediate, or low. Assessment included mobility functions (6-minute walk, mobility skills, reach, 10ft walk time) and physiological components of balance: sensory (vibration, proprioception, vision, vestibular), effector (ankle, knee, hip strength, range of motion), and central processing (response time to perturbations). All mobility functions were significantly (p < .05) different between groups. Impairments in components of postural control were rarely different between groups: the major differences were in ankle strength and visual fields. The number of impaired domains differed across the three groups. Nineteen percent of the low group had at least three domains impaired; none of the intermediate or high groups were impaired in three domains. Fifty-six percent of the low, 20% of the intermediate, and 7% of the high were impaired in two or more domains. Variability in specific mobility measures was also predicted by the number of impaired domains. The decline in physical function may be better explained by the accumulation of deficits across multiple domains than by any single specific impairment.

Accidental Falls↗
PubMed1993

When older adults face the chair-rise challenge. A study of chair height availability and height-modified chair-rise performance in the elderly.

OBJECTIVE: Define the range of community seating heights available for use by older adults; test whether raising chair height by small increments facilitates chair-rise performance; and heighten physician and furniture industry awareness of discrepancies that may exist between actual and acceptable chair heights for older adults. DESIGN: Phase 1: Survey of commercially available chair heights. Phase 2: Cross-sectional descriptive study of chair-rise ability. SETTING: Phase 1: Local furniture stores, physician offices, hospital waiting areas, and nursing homes. Phase 2: Postural Control Lab. PARTICIPANTS: Twenty-two volunteers (nursing home residents and community dwellers). EXCLUSION CRITERIA: inability to stand independently and inability to bear full weight on the lower extremities in the standing position. MEASUREMENTS: Chair rise success at six heights (17-22 inches), self-reported difficulty (visual analogue scale), change in minimum hip angle and maximum shoulder angle during rise, using motion analysis. RESULTS: Phase 1: Community chair heights ranged from 12 to 18 inches, with a mean of 16.3 in physician offices, 16.6 in nursing homes, 16.4 in hospitals, 17.3 in "kitchens" and 15 in "living rooms." Phase 2: As chair height increased from 17 to 22 inches, chair rise effort decreased, as shown by near doubling of percent successful rises, decline in mean self-reported difficulty score, increase in mean minimum hip angle, and decrease in mean maximum shoulder angle. CONCLUSIONS: Seating height may need to be more closely scrutinized in areas frequented by frail elders. Augmentation of seat height by small increments facilitates chair rise performance.

Activities of Daily Living↗
PubMed1992

Functional reach: predictive validity in a sample of elderly male veterans.

A new measure of balance, functional reach, has been recently developed. Functional reach is the maximal distance one can reach forward beyond arm's length while maintaining a fixed base of support in the standing position. Reliability, criterion, and concurrent construct validity of functional reach have been established. The purpose of this study was to assess the predictive validity of functional reach in identifying elderly subjects at risk for recurrent falls. Two hundred and seventeen elderly, community-dwelling male veterans (aged 70-104) underwent baseline screening and were followed for 6 months to monitor falls. Subjects with two or more falls during the 6-month follow-up were classified as recurrent fallers. Logistic regression reveals that if individuals were unable to reach, the adjusted odds ratio (OR) of having two falls was 8.07 (2.8-23.71); if their reach was less than or equal to 6 inches the OR was 4.02 (1.84-8.77); and if reach was greater than 6 inches but less than 10 inches the OR was 2.00 (1.35-2.98). The association between functional reach and recurrent falls was not confounded by age, depression, or cognition. We conclude that functional reach is a simple and easy-to-use clinical measure that has predictive validity in identifying recurrent falls.

Accidental Falls↗
PubMed1992

Functional reach: a marker of physical frailty.

OBJECTIVE: To establish the concurrent validity of our new balance instrument, functional reach (FR = maximal safe standing forward reach), as a marker of physical frailty compared with other clinical measures of physical performance. DESIGN, SETTING AND PARTICIPANTS: 45 community-dwelling persons age 66-104 were evaluated at one point in time using (1) FR (yardstick method), (2) Physical and Instrumental Activities of Daily Living (PADL, IADL), (3) Life Space, a 3-point measure of social mobility, (4) 10-item hierarchical mobility skills protocol, (5) 10-foot walking speed, (6) one-footed standing, and (7) tandem walking. Data analysis employed Spearman correlations. Partial r's were also calculated after controlling for age. RESULTS: The FR performance range was broad (4.3-16.5 inches, mean 10.9, SD 3.1). Except for PADL, the association of FR with the other physical performance measures was strong, with r's ranging from 0.64-0.71; the association of FR with PADL was 0.48. After controlling for age in the regression analysis, partial r's ranged from 0.52-0.63. The association of FR with age was -0.50. CONCLUSIONS: Based on cross-sectional data, FR is a practical instrument that correlates with physical frailty even more than with age.

Activities of Daily Living↗
PubMed1992

Epidemiology and pathogenesis of paranasal sinus mycoses.

In a prospective study, 50 cases of paranasal sinus mycoses were diagnosed in 2 years out of 119 clinically suspected patients from north India. Young men from rural areas were most commonly afflicted. Patients with paranasal sinus mycoses could be grouped in three clinical varieties: noninvasive, 31; invasive, 17; allergic, 2. Maxillary and ethmoid were the common sinuses concurrently involved in these patients, whereas sphenoid and frontal sinuses were also affected in invasive variety. Aspergillus flavus (80%) was the most common isolate, followed by A. fumigatus (6%). Alternaria species was identified in two patients with noninvasive granuloma. In invasive variety, Rhizopus arrhizus and Candida albicans were the causative agents in two patients and one patient, respectively. Regarding pathogenesis besides epidemiologic factors, the immunologic factors were also evaluated. It was found that presence or absence of precipitating antibody against antigens from the etiologic agents correlates well with disease progression. Allergic factor was found in all varieties, though presence of cell-mediated immunity was demonstrated in 29% patients with noninvasive granuloma only. The combination of skin test against aspergillin and precipitin demonstration at the outset will therefore help in preliminary screening.

Adolescent↗
PubMed1991

Vision research in departments of ophthalmology. An Association of University Professors of Ophthalmology perspective.

A research committee of the Association of University Professors of Ophthalmology disseminated a survey questionnaire to determine the state of research in departments of ophthalmology across the United States. The questionnaire contained 71 questions that were designed to assess attitudes and trends within members' departments and to solicit suggestions from the membership. Of the 145 members and affiliates queried, 140 responded. While the results of the survey indicate significant diversity among departments, departmental chairpersons view research as a major priority in the goals of their departments, and they envision maintenance or expansion of research over the next decade. The survey results have been collated and serve now as the basis for this Association of University Professors position article.

Humans↗
PubMed1991

Nurse Education Tomorrow Conference 1990. Reforming nurse education. 1--The reorganisation of nursing knowledge.

With the development of Project 2000, nurse education is being increasingly drawn into higher education with the expansion of diploma and degree courses. This paper explores the implications of these new relationships, drawing on the sociology of the curriculum and education in its analyses. It examines the impact of these changes on the professional standing of nurses and nursing and the reorganisation of the curricular codes that underpin nurse education. A movement towards higher education will introduce a new educational culture into nurse training and the wide multi-disciplinary base of nursing knowledge and practice will offer new challenges to nurse educators. The changes in nurse education add a new dynamic to the old tensions between academic and vocational training and raise new questions about the relationship of nurse education to the academic tribalism of higher education.

Curriculum↗
PubMed1991

Nurse Education Tomorrow Conference 1990. Reforming nurse education. 2--Implications for teachers and students.

The development of Project 2000 will lead to the reorganisation of nursing knowledge as nurse education enters higher education. This paper explores the implications of these changes for the future of role of nurse teachers and the new choices for professional development as teachers evolve into nursing theorists, lecturer practitioners and educational managers. The paper also explores changing pedagogic relationships with students, changing assessment strategies, their new supernumerary position in clinical environments, and reference groups likely to be selected by students. Finally it examines the ways in which links with higher education and the contributions of non-nurse academics may lead to the reorganisation of course management structures.

Education, Nursing↗
PubMed1991

Mortality among industrial workers exposed to phenol.

We conducted a follow-up study to evaluate mortality among 14,861 workers employed in five facilities producing or using phenol and formaldehyde. More than 360,000 person-years of follow-up accrued. Mortality rates from all causes of death combined were similar to those in the general U.S. population. We observed excesses of cancer of the esophagus, cancer of the kidney, and Hodgkin's disease among workers exposed to phenol, but none of these excesses showed a dose-response relation with exposure to phenol. Excess lung cancer mortality (SMR = 1.2) showed no consistent pattern by any exposure index. Workers exposed to phenol had lower mortality ratios for cancer of the buccal cavity and pharynx, cancer of the stomach, cancer of the brain, arteriosclerotic heart disease, emphysema, disease of the digestive system, and cirrhosis of the liver. Of these, arteriosclerotic heart disease, emphysema, and cirrhosis of the liver were inversely related to duration of phenol exposure and to cumulative phenol exposure levels. Although these inverse associations may be due to chance or uncontrolled confounders, the ability of phenol to interfere with the generation of oxidants in experimental systems suggests that the pattern may have biologic plausibility.

Adult↗
PubMed1991

Postural responses and effector factors in persons with unexplained falls: results and methodologic issues.

Automatic postural responses and effector factors were examined in 10 persons with unexplained falls after clinical examination and 24 older controls. Fallers were more unstable than controls on clinical tests of balance (20% of fallers vs 79.2% of controls were able to stand on one foot (P less than .005), 40% of fallers and 100% of controls were stable while turning in place (P less than .001), postural stress test median score was 12 for fallers and 20 for controls (P less than 0.001). We found prolonged tibialis anterior latency (fallers 158.8 +/- 23.7, controls 143.2 +/- 15.7 milliseconds, P = 0.03), marked losses in ankle strength (dorsiflexion: faller 3.2 +/- 2.9, controls 8.9 +/- 4.2 foot-pounds, P less than 0.001; plantarflexion: fallers 7.9 +/- 5.3, controls 21.4 +/- 11.1 foot-pounds, P less than 0.001), and decreases in range of motion (ankle plantarflexion: fallers 29.2 +/- 7.0, controls 37.8 +/- 12.4 degrees, P = 0.02). Gastrocnemius latency and electromyographic (EMG) measures of sequence showed no differences between fallers and controls. Sequence measures were not symmetric between the lower extremities in either fallers or controls. In this population of persons with unexplained falls who demonstrated substantial impairments in functional balance, effector factors appear more impaired than automatic postural responses. Alternatively, contemporary analysis of automatic postural responses may require further development before it can be useful to study balance problems in older persons.

Accidental Falls↗