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Biomedical subjects

J Goodwin

Publications and source records attributed to J Goodwin.

At least 19 recordsLinked to original sources
PubMed2001

Structural and oxo-transfer reactivity differences of hexacoordinate and pentacoordinate (nitro)(tetraphenylporphinato)cobalt(III) derivatives.

The oxo-transfer catalyst (nitro)(pyridyl)cobalt(III) tetraphenylporphyrin has been reinvestigated by substitution of the distal pyridine ligand with 4-N,N-dimethylaminopyridine and 3,5-dichloropyridine. Differences in their structures and in the reactivity of the compounds toward catalytic secondary oxo transfer were investigated by FT-IR and UV-visible spectroscopy, cyclic voltammetry, X-ray diffraction, semiempirical calculations, and reactions with alkenes in dichloromethane solution. Very modest differences in the hexacoordinate compounds' structures were predicted and observed, but the secondary oxo-transfer reactivity at the nitro ligand varies markedly with the basicity of the pyridine ligand and the position of the coordination equilibrium. Oxo transfer occurs rapidly through the pentacoordinate species (nitro)cobalt(III) tetraphenylporphyrin that is generated by dissociation of the pyridine ligand and therefore is strongly related to the Hammett parameters of these nitrogenous bases. The reactive pentacoordinate species CoTPP(NO(2)) can be generated in solution by addition of lithium perchlorate to (py)CoTPP(NO(2)) by Lewis acid-base interactions or more simply by using the weaker Lewis base Cl(2)py instead of py as the distal ligand. In contrast to pentacoordinate (nitro)iron porphyrins, disproportionation reactions of CoTPP(NO(2)) compound are not evident. This pentacoordinate derivative, CoTPP(NO(2)), is reactive enough to stoichiometrically oxidize allyl bromide in minutes. Preliminary catalytic oxidation reaction studies of alkenes also indicate the involvement of both radical and nonradical oxo-transfer steps in the mechanism, suggesting formation of a peroxynitro intermediate in the reaction of the reduced CoTPP(NO) with O(2).

Journal Article↗
PubMed2001

Seasonal cold and circadian changes in blood pressure and physical activity in young and elderly people.

AIM: To test the hypothesis that there is no association between seasonal cold and the circadian responses of blood pressure, deep-body temperature and physical activity in healthy young and elderly men. METHODS: 25 healthy elderly (aged 70-82 years) and 21 young volunteers (aged 20-30 years) participated in a 3-year prospective cross-seasonal study. RESULTS: Ambulatory day-time blood pressures in the older men were higher in the winter than in the summer and higher in both seasons than in the young people. The seasonally related differences were associated with lower outdoor and indoor temperatures, lower body temperature and higher activity levels in the elderly group in the winter. The older but not the younger group had higher blood pressure and levels of physical activity at certain times of the day in the winter compared with the summer. CONCLUSION: Time-of-day winter increases in blood pressure in older people may be related to increased activity as well as to levels of ambient temperature. Although it is generally advantageous for older people to be physically active in order to prevent circulatory disease, there may be a rationale for advising that that they should avoid intense activity at certain times of the day, especially in the winter.

Adult↗
PubMed2001

The effect of fluid replacement on endurance performance.

The purpose of this study was to examine the effects of fluid replacement on power output (PO), rating of perceived exertion (RPE), heart rate (HR), body weight (BW), urine osmolarity (Uosm), and urine electrolyte concentrations ([UNa+], [UK+], [UCl-]) in physically active men (n = 4) and women (n = 7). The participants were asked to generate their highest possible PO during 60 minutes of cycling under 3 randomized conditions: ingestion of (a) no fluid (trial 1); (b) 1200 ml of distilled water (trial 2); and (c) 1,200 ml of Gatorade (trial 3). BW and urine volume (Vu) were measured before and after the ride to determine sweat rate [(SR = deltaBW + Vfluid intake + Vu)/time]. The results indicated that there were no significant differences between trials for PO (123-127 W), RPE (14), HR (140-142 b x min(-1)), and SR (11.9-12.4 ml x min(-1)). However, [UNa+] was significantly (p < 0.05) lower postexercise for all 3 trials, and [UCl-] was significantly reduced following trials 2 and 3. There was a significant increase (p < 0.001) in BW postexercise for trials 2 and 3 when compared with the no-fluid trial; however, the effects of water and Gatorade were similar. These results suggest that fluid replacement during 1 hour of moderately intense cycling does not enhance performance in physically active men and women who are normally hydrated.

Adult↗
PubMed2000

Seasonal cold, excursional behaviour, clothing protection and physical activity in young and old subjects.

Previous reports indicate that everyday excursional exposures may play a part in increased winter mortality (Donaldson et al 1997) and that the avoidance of cold stress is associated with low indices of cold related mortality in Europe (Eurowinter Group 1997). However, few prospective data have been reported on excursional data and risk factors for arterial disease. In a field study carried out on 21 young (mean age 23.5) and 24 elderly healthy subjects (mean age 73.6) there were no significant differences between winter and summer in the number or duration of outside excursions. Never the less, elderly subjects had significantly more clothing insulation (clo), both indoors and outdoors in the winter than in the summer (p < or = 0.001) and this was also the case for young subjects. The urine temperature of the elderly in the winter was significantly lower (p < or = 0.01) than in the summer but this was not seen in the young. Elderly physical activity was significantly higher in the winter than in the summer (p < or = 0.05) but not for the young. Thus, elderly subjects showed no material change in excursional behaviour in the winter, even though clothing protection was arguably inadequate in view of lower body temperature, accompanied by increased physical activity. Blood pressure was significantly higher in the winter (p < or = 0.01) in the elderly, though the extent to which activity levels contributed to this contrast is uncertain from these data.

Adult↗
PubMed1999

Urinary myelin basic protein-like material in patients with multiple sclerosis during interferon beta-1b treatment.

OBJECTIVES: To determine levels of urinary myelin basic protein-like material (MBPLM) in patients with multiple sclerosis (MS) openly treated with interferon beta-1b and to correlate these with clinical changes. BACKGROUND: Levels of urinary MBPLM correlate with the presence of the progressive phase of MS and with the disease burden detected on T2-weighted, cranial magnetic resonance imaging. Measurement of urinary MBPLM level may be a feasible test for monitoring or predicting response to therapeutic measures. DESIGN AND METHODS: In a prospective study at one site, 166 patients with MS (131 with relapsing-remitting [RR] and 35 with secondary progressive [SP] disease) were treated for a minimum of 1 year and up to 3 years with interferon beta-1b and underwent assessment for neurologic disability (Expanded Disability Status Scale and Scripps Neurological Rating Scale) and change in disease subtype. Urine samples were obtained at 1219 of 1378 clinic visits, and urinary MBPLM level was determined and related to creatinine level to adjust for renal function. RESULTS: Statistical analysis using the general linear models procedure confirmed previous findings that the level of urinary MBPLM related to urinary creatinine level (MBPLM/creatinine) was higher (P<.001) in patients with SP than RR MS. Of the 131 patients with RR MS, SP disease developed in 13 during the observation period. Compared with those in the RR group, the RR to SP group had a higher level (P<.001) of urinary MBPLM and did not differ from the SP group. CONCLUSIONS: The level of urinary MBPLM is higher in SP MS than RR MS but not in RR MS that converts to SP MS. Level of urinary MBPLM may permit the examination of treatment tested to prevent RR disease from becoming progressive.

Adjuvants, Immunologic↗
PubMed1999

Optic nerve sheath meningiomas. Role of MR imaging.

Optic nerve meningiomas usually are seen in middle-aged and elderly women, and present as a slowly progressing axial proptosis and loss of vision. CT and MR imaging are the most valuable diagnostic tools to evaluate these tumors. This article reviews the MR imaging and CT characteristics of optic nerve sheath meningiomas and discusses features that may distinguish optic nerve sheath meningiomas from simulating lesions.

Aged↗
PubMed1998

Telekid Care: bringing health care into schools.

BACKGROUND: Telekid Care is a project that attempts to overcome the health and educational barriers faced by children in urban Kansas City, Kansas. Telemedicine units were placed in school nurses' offices and linked to physicians at the University of Kansas Medical Center (KUMC). This paper describes the development of this project, presents utilization data, and discuss the lessons learned from the application of telemedicine in a school setting. RESULTS: Project developers spent 11 months designing the protocol and procedures for a pilot test. Four elementary schools participated, and 187 consultations were conducted. The most common reason for consultation was ear, nose, and throat (ENT) problems, making up 28% of all consults. Mandatory school physical examinations and dermatology problems combined to make up an additional 40% of the consults. The average time that elapsed between the request for a consult and confirmation of an appointment was 23 minutes. When immediate service was requested, 85% of the consults occurred the day of the request. These results strongly demonstrate telemedicine's ability to offer immediate service to children in need. CONCLUSION: Telemedicine enabled underserved inner-city children to gain access to health services. This service was most effective when it was integrated into the delivery system. Furthermore, community groups strongly favored the project, positively influencing its acceptance as an innovative health care delivery system.

Appointments and Schedules↗
PubMed1998

Correlates of prescription and over-the-counter medication usage among older Mexican Americans: the Hispanic EPESE study. Established Population for the Epidemiologic Study of the Elderly.

OBJECTIVES: To determine the prevalence rates of prescription and over-the-counter (OTC) medication usage among community-dwelling older Mexican Americans. DESIGN: Cross-sectional survey of a regional probability sample of older Mexican Americans. SETTING: The 1992-1997 Hispanic Established Population for the Epidemiologic Study of the Elderly (H-EPESE), a probability sample of noninstitutionalized Mexican Americans, age 65 and over, living in the five Southwestern states of Texas, New Mexico, Colorado, Arizona, and California. PARTICIPANTS: 2899 persons, age 65 and over, considered Mexican American, using appropriate weighting procedures to produce regional estimates. OUTCOME MEASURES: Use of prescription and OTC medication within the last 2 weeks before the survey confirmed by in-home review of medication containers. RESULTS: Medication users consumed a mean of 2.9 prescription and 1.3 OTC medications. Over half (58.9%, n = 1,798) of the participants used at least one prescribed medication, and 31.3% (n = 847) used at least one OTC medication within the 2 weeks before their participation in the study. Factors associated with both prescription and OTC medication usage were self-perceived health and number of co-morbid conditions. Factors associated only with prescription medication usage included female gender, alcohol usage, ADL dependency, and presence of additional insurance. Structural assimilation was associated only with OTC medication usage. CONCLUSIONS: These data show lower prevalence rates of prescription medication usage among Mexican American older men and lower rates of OTC medication usage in older Mexican Americans of both genders than previously reported in other ethnic groups. This may reflect differences in time and geographic location of the Hispanic EPESE relative to other EPESE studies, ethnic differences in access to care as reflected by insurance in addition to Medicare, ethnic differences in survival, especially among males, or ethnic differences in medication preferences.

Activities of Daily Living↗
PubMed1998

Age-related changes in the level of urinary myelin basic protein-like material during childhood.

OBJECTIVE: To examine the developmental profile of myelin basic protein-like material (MBPLM) in urine. If urinary MBPLM exhibits a developmental profile corresponding to that of forebrain myelination, certain inferences should follow deviations from normal. Thus, MBPLM might provide a marker for monitoring the neurodevelopmental status in infants at risk for adverse outcomes. BACKGROUND: MBPLM in different immunochemical forms is detectable in human CSF and urine, presumably a result of myelin basic protein (MBP) catabolism. Urinary MBPLM has been used successfully as a marker of disease status in adults with MS. Urinary MBPLM increases in MS patients changing from a relapsing-remitting to a progressive course, possibly reflecting attempted or failed remyelination. Scant information exists concerning the presence or specific levels of urinary MBPLM during infancy and childhood when myelination is most active. METHODS: MBPLM was assayed in 402 urine specimens from 398 infants and children ranging in age from birth to 17 years according to previously described methods. RESULTS: MBPLM is detectable in urine from newborns, although at substantially lower levels than in adults (157.3 +/- 83.9 ng/mg creatinine). Whether expressed as nanograms per milliliter urine or nanograms per milligram creatinine, MBPLM levels are lower (p < 0.05) from birth through 12 months and greater (p < 0.05) between ages 2 to 8 years than in adults. CONCLUSION: Human urinary MBPLM exhibits a developmental profile that parallels the onset of normal myelination and exceeds normal adult values through early childhood. Thus, urinary MBPLM could serve as a useful marker of myelination in the developing child.

Adolescent↗
PubMed1997

Impact of psychosocial factors on health outcomes in the elderly. A prospective study.

One hundred and thirty-five initially healthy men and women older than 65 years of age were studied prospectively to identify factors associated with health outcomes. At study onset, measures of personality, social interaction, and health locus of control were obtained while participants were still healthy. A reliable health outcome measure was developed, based on the annual objective coding of morbidity. Correlations between variables showed significant associations between age, a less independent personality trait, and poor health outcomes. Anxiety and low levels of social interaction were associated with poor health after 8 years. Gender and health locus of control were not significantly related to health outcomes. A path analysis showed significant direct paths between age and trait anxiety and 8-year health outcomes, and indirect paths between anxiety and extroversion and 8-year health, by way of social interaction. There was no evidence that social interaction mediated the effects of either anxiety or extroversion on health. The structure of psychosocial characteristics of the healthy elderly sample was revealed in the pattern of correlations between personality, social interaction, and locus of control.

Aged↗
PubMed1996

Genetic and biochemical dissection of transgenic RNA-mediated virus resistance.

RNA-mediated virus resistance has been observed in transgenic plants at varying frequencies, suggesting that a nuclear requirement or other pre-condition must be met. This study was undertaken to characterize genetically transgenes that confer a highly resistant state to infection by tobacco etch virus (TEV). Transgenic tobacco line 2RC-6.13, expressing an untranslatable mRNA containing the TEV coat protein open reading frame, had three distinct transgene integration events that segregated as two linkage groups. A genetic series of plants that contained zero, one, two, or all three transgene inserts in both homozygous and heterozygous conditions was produced and examined. Genetic and biochemical data suggested that RNA-mediated virus resistance is a multigenic trait in line 2RC-6.13; three or more transgenes were necessary to establish the highly resistant state. One or two transgene copies resulted in an inducible form of resistance (i.e., recovery). Transcription rates and steady state RNA levels of the transgene-derived transcript present in different members of the genetic series supported a post-transcriptional RNA degradation process as the underlying mechanism for transgene transcript reduction and virus resistance. This degradation process appeared to initiate via cleavage of specific sites within the target RNA sequence, as determined by RNA get blot and primer extension analyses of transgene-derived mRNA from various transgenic plant lines.

Capsid↗
PubMed1996

Fat and carbohydrate metabolism during exercise in elderly and young subjects.

We evaluated the effect of aging on fat and carbohydrate metabolism during moderate intensity exercise. Glycerol, free fatty acid (FFA), and glucose rate of appearance (Ra) in plasma and substrate oxidation were determined during 60 min of cycle ergometer exercise in six elderly (73 +/- 2 yr) and six young adults (26 +/- 2 yr) matched by gender and lean body mass. The elderly group was studied during exercise performed at 56 +/- 3% of maximum oxygen uptake, whereas the young adults were studied during exercise performed at the same absolute and at a similar relative intensity as the elderly subjects. Mean fat oxidation during exercise was 25-35% lower in the elderly subjects than in the young adults exercising at either the same absolute or similar relative intensities (P < 0.05). Mean carbohydrate oxidation in the elderly group was 35% higher than the young adults exercising at the same absolute intensity (P < 0.001) but 40% lower than the young adults exercising at the same relative intensity (P < 0.001). Average FFA Ra in the elderly subjects was 85% higher than in the young adults exercising at the same absolute intensity (P < 0.05) but 35% lower than the young adults exercising at a similar relative intensity (P < 0.05). We conclude that fat oxidation is decreased while carbohydrate oxidation is increased during moderate intensity exercise in elderly men and women. The shift in substrate oxidation was caused by age-related changes in skeletal muscle respiratory capacity because lipolytic rates and FFA availability were not rate limiting in the older subjects.

Adult↗