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Biomedical subjects

R C Wood

Publications and source records attributed to R C Wood.

At least 37 records · Page 2Linked to original sources
PubMed1993

Women defining health: food, diet and body image.

This article explores the relationship between gender and food through analysing data obtained from a series of women-only discussion groups, the participants of which explored self definitions of the term 'health'. What is distinct about this data, collected in the North East of England, is the clear link respondents perceive between food, diet and health. However, due to a number of factors such a knowledge may not result in dietary and ultimately bodily change. The many implications of such findings for health education are outlined in the discussion section of the paper.

Adult↗
PubMed1993

The role of nonionic myelography in the diagnosis of lumbar disc herniation.

RATIONALE AND OBJECTIVES: The accuracy and safety of nonionic myelography, unenhanced computed tomography (CT), and magnetic resonance (MR) in the diagnosis of lumbar disc herniation are reviewed. The comparative costs of these tests are also considered. METHODS: The accuracy of imaging tests that diagnose disc herniations was established by conducting a Medline search between 1985 and 1992. The morbidity associated with these tests are less formally established from selected articles. Finally, the mediocre reimbursement rates of these tests are reviewed. RESULTS AND CONCLUSIONS: The evolution of nonionic contrast media from the first to the second generation has been accompanied by a notable decrease in adverse reactions. Although nonionic myelograms are now better tolerated by patients, noninvasive imaging with CT and MR imaging has become as accurate as or more accurate than lumbar myelography, and should replace it as a screening test. Computed tomography may have advantages over MR imaging when issues of availability and cost are considered. In contrast to lumbar myelography, CT myelography may continue to be a useful method for clarifying ambiguous results of noninvasive tests. The morbidity associated with CT myelography can be minimized by using low doses of a nonionic agent, keeping the patient well hydrated, and using a small lumbar puncture needle. The incidence of adverse reactions can be expected to decrease further as new nonionic dimers become clinically available.

Contrast Media↗
PubMed1993

Relationship of "bleeding on probing" and "gingival index bleeding" as clinical parameters of gingival inflammation.

Bleeding on probing (BOP) and the gingival index have been used to clinically characterize the degree of gingival inflammation. It is, however, unclear to what extent these parameters correlate to each other and to probing pocket depth (PD). The purpose of this clinical study was to evaluate the association between BOP and GI bleeding (scores of 2 and 3), as well as the relationship of these variables to PD, in a group of patients presenting with naturally-occurring gingivitis. Based on screening examinations of 125 subjects with at least 20 teeth, no more than 4 sites with PD over 6 mm, a BOP frequency of 30% or greater, and no systemic condition that would influence the inflammatory response, were selected. 2 weeks after screening they were examined at 6 sites per tooth for plaque index, GI, PD and BOP. A standardized pressure sensitive probe (Florida Probe) with 20 g probing force was used for BOP and PD measurements. In this population, means of 40.9% (S.E. = 1.36) BOP sites and 35.3% (S.E. = 1.81) GI bleeding sites per patient were found. A total of 20,008 sites ranging in PD up to 5.9 mm were evaluated; however, the majority of sites (19,723, 98.6%) presented with < 4 mm PD. When sites were evaluated, BOP demonstrated a positive correlation with PD, whereas GI bleeding correlated with PD. For sites characterized by the absence of BOP as well as the absence of GI bleeding (scores 0 and 1), the highest % of agreement between the 2 indices (77.7%) was found in shallow sites (0.1-2 mm).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1993

Building-related asthma in Denver office workers.

OBJECTIVES: Reported cases of building-related asthma and hypersensitivity pneumonitis among workers in a Denver office building prompted an epidemiologic investigation. METHODS: A cross-sectional, self-administered survey of employees in the office building of the reported cases was compared with that of employees in a comparison building. RESULTS: A significant excess of respiratory disease existed among 512 Denver workers (case building) compared with 281 office workers in a suburban agency (control building). Denver employees had a higher prevalence of respiratory symptoms, and the prevalence of physician-diagnosed asthma with onset or exacerbation since building occupancy was 4.9 times greater for Denver employees than for suburban employees. Asthma was not associated with any particular ventilation system in the building. Water incursion from a below-grade wall may have contributed to the problem, but the etiology is unknown. CONCLUSIONS: This investigation provided evidence of office building-related asthma. Individual cases may be sentinel events for other cases of work-related asthma or hypersensitivity pneumonitis and may indicate a need for public health investigation of remediable causes.

Adult↗
PubMed1992

Campylobacter enteritis outbreaks associated with drinking raw milk during youth activities. A 10-year review of outbreaks in the United States.

OBJECTIVE: To determine the incidence of recognized outbreaks of Campylobacter enteritis associated with drinking raw milk during youth activities. DESIGN: Retrospective survey of 51 state and territorial health departments. SETTING: The 50 United States and the Territory of Puerto Rico. POPULATIONS: Persons in preschool through college. MEASUREMENT: Information was obtained for all Campylobacter outbreaks associated with consumption of raw milk during youth activities from 1981 through 1990 that were investigated by state and territorial health departments. RESULTS: Twenty outbreaks were identified in 11 states. Four hundred fifty-eight outbreak-associated cases occurred among 1013 persons who drank raw milk, with an overall attack rate of 45%. At least one outbreak was reported for each year of the 10-year period. Fourteen outbreaks (70%) occurred among children in kindergarten through third grade, compared with one outbreak (5%) among fourth through sixth graders. The remaining five outbreaks (25%) occurred in mixed groups of children and teenagers. Only nine (60%) of 15 outbreaks identified from 1981 through 1988 were reported to the Campylobacter national surveillance system maintained by the Centers for Disease Control and Prevention. CONCLUSION: Drinking raw milk on school field trips or other youth activities continues despite the occurrence of multiple Campylobacter outbreaks documented from this practice. Such illnesses can be prevented by educating dairy farmers and officials of schools and youth organizations about the hazards of drinking raw milk. Public health organizations need to develop and implement such educational programs.

Adolescent↗
PubMed1990

What is twin birthweight discordance?

The purpose of this study was to define the level of twin birthweight discordance across gestational age at which perinatal morbidity, neonatal death, or congenital anomalies were more likely to occur. One hundred ninety-four sets of twins (1982-1985) were retrospectively studied. Discordance was defined as (birthweight of larger-birthweight of smaller/birthweight of larger) x 100. The mean discordance was 10.3 +/- 8.5% (26 to 32 weeks = 7.6 +/- 5.9%; 33 to 36 weeks = 9.5 +/- 9.5%; 37 to 42 weeks = 11.4 +/- 8.5%) (p = 0.07). The occurrence of morbidity, neonatal death, and anomalies was increased with prematurity or the occurrence of small for gestational age in both twins. However, neither morbidity, neonatal death, nor anomalies were significantly related to level of discordance. These data demonstrate that prematurity and birthweight below the tenth percentile may present a greater threat to twins than does birthweight discordance. These findings should be given due consideration in planning antepartum management.

Birth Weight↗
PubMed1990

Presentation of antigen to suppressor cells by a dimethylbenz (a) anthracene-resistant, Ia-positive, Thy-1-negative, I-J-restricted epidermal cell.

The epidermal layer of the skin contains class II major histocompatibility (MHC)-positive antigen-presenting cells (APC), the most well characterized population being Langerhans' cells (LC). The chemical carcinogen 7,12 dimethylbenz (a) anthracene (DMBA) depletes about two-thirds of these cells from murine epidermis, and contact sensitizers applied to DMBA-treated skin induce specific immunological tolerance. This tolerance results from epidermal cells migrating to local lymph nodes within 3-6 hr after contact with antigen where they present the antigen to suppressor cells. Here we demonstrate that this epidermal cell which activates suppressor cells is a class II MHC-positive. Thy-1-negative, I-J-restricted APC. Hence at least two types of class II MHC-positive epidermal cells migrate to local lymph nodes and present antigen to lymphocytes; LC, which are sensitive to the effects of DMBA and activate helper lymphocytes, and another, which is resistant to DMBA and activates suppressor cells in an I-J-restricted manner. During the early stages of carcinogenesis any antigen present in the epidermis would be presented only by the cells which activate suppressor lymphocytes, resulting in tolerance induction. This may enable neoplastic cells to avoid the initiation of anti-tumour immunity.

9,10-Dimethyl-1,2-benzanthracene↗
PubMed1989

Bilateral anterior transposition of the inferior obliques.

Sixty-one children with bilateral overaction of the inferior oblique muscle with concurrent or previous infantile esotropia received bilateral inferior oblique recessions with anteriorization to a point 2 to 4 mm anterior to the lateral end of the inferior rectus insertion. Subsequent reoperation for recurrent overaction of the inferior obliques was needed in only one case. Also, substantial reduction in dissociated vertical deviation (DVD), when present, and almost complete absence of subsequent need for surgery for DVD among the 61 children of this series were new findings. Only one of the 61 required subsequent surgery for manifest DVD. In another series of 60 infantile esotropes of similar ages drawn from the same practice who had previously had no inferior oblique surgery, nine needed surgery for DVD. This difference (one of 61 vs nine of 60) was significant.

Child↗
PubMed1989

Correction of density changes caused by methodological errors in CADIA.

Quantitative evaluation of radiographic changes by computer-assisted densitometric image analysis (CADIA) requires exact knowledge about method errors. In the present study, density change errors were determined from pairs of films with "no change". From this distribution of error values, a series of threshold values for correction of changes due to method errors was selected. The threshold values were then applied to results from analysis of densitometric changes in sites with "known loss" or "no change" of the alveolar bone among films from cynomolgus monkeys. The density errors formed non-normal distributions with no difference in magnitudes between the absolute values expressing density decreases and density increases in the same areas. Calculation of sensitivity, specificity, type 1 and type 2 errors showed that these variables were clearly influenced by selection of different threshold values for correction of the density change errors. It is therefore recommended that threshold values be determined for each analytical system initially as well as following any equipment or computer program modification. Before selecting the threshold value for a specific radiographic analysis, the desired level of sensitivity and specificity should be evaluated.

Absorptiometry, Photon↗
PubMed1989

Therapeutic ultrasound for refractory glaucoma: a three-center study.

We present the results of therapeutic ultrasound for refractory glaucoma in a three-center study over 1 year. One hundred fifty-eight eyes were treated, with a mean follow-up of 8.0 months. The mean fall in intraocular pressure was 38.4%. Life table analysis for three success criteria are presented. Success varied between 66% and 72% at the mean follow-up time. Complications occurred in 11.4%, including phthisis bulbi in 0.6% and persistent hypotony in 2.5%. There was a mean loss of less than one line of visual acuity. Therapeutic ultrasound appears to be safe and effective for treatment of refractory glaucoma.

Adult↗
PubMed1986

Variability of strabismus surgery for acquired esotropia.

We developed a mathematical model to predict the probable success rate of the first surgery to correct acquired esotropia with normal accommodative convergence-accommodation ratio in children. A computer-averaged dose-response curve of the effect of 68 bilateral medial rectus recessions was combined with various assumptions regarding likely errors in surgical performance and likely errors in measurement of the preoperative deviation. Fifteen different sets of reasonable assumptions were tested, giving a range of theoretical success rates from 72% to 96%. The results of this study clearly indicate that a certain proportion of failures is to be expected when this or other forms of strabismus are treated surgically by a fully competent ophthalmic surgeon performing as accurately as is practically possible.

Child↗
PubMed1986

Analysis of birth weight percentile as a predictor of perinatal outcome.

Birth weight-gestational age tables are convenient methods for the neonatal evaluation of intrauterine growth, however, the limits of acceptable birth weight for gestational age are controversial. The purpose of this study was to identify the birth weight percentiles that accurately predicted poor perinatal outcome from 28 through 41 weeks' gestational age. In a homogeneous population of 44,811 patients, the birth weight percentile that predicted poor perinatal outcome varied with gestational age. The birth weight percentile that predicted normal outcome in 80% of normal patients declined from the 55th percentile at 28 to 29 weeks to the 24th percentile at 34 to 35 weeks. From 28 through 35 weeks' gestational age, possibly owing to the confounding effects of prematurity, patients classified as normal by birth weight criteria still had a significant risk of poor outcome. After 36 weeks' gestational age, poor perinatal outcome occurred in 3.9% of patients and tended to occur at the extremes of birth weight. Classification by birth weights approximating the tenth and 90th percentiles identified a population in which the majority of the poor perinatal outcome occurred. However, poor outcome occurred in only 10% of patients with birth weights below the tenth or above the 90th percentiles. Among those with birth weights between the tenth and 90th percentiles, outcome was normal in 98%. Therefore, from 36 through 41 weeks' gestational age, the prevalence of poor perinatal outcome was low, and birth weight percentile was a weak predictor of outcome in the individual patient.

Birth Weight↗
PubMed1986

Birth weight percentile and perinatal outcome: recurrence of intrauterine growth retardation.

In 9596 patients followed throughout two pregnancies, recurrence of intrauterine growth retardation (IUGR) was evaluated as a function of previous birth weight percentile and attendant complications of pregnancy. Among 4623 patients with two uncomplicated pregnancies, the prevalence of recurrent IUGR was significantly related to the severity of growth retardation in the first pregnancy (P less than .0001). Those patients with both medical complications and IUGR in the first pregnancy remained at significantly increased risk for recurrent IUGR, even when the second pregnancy was uncomplicated. In second pregnancies, the combination of a previous history of an IUGR neonate and an additional current complication of pregnancy acted synergistically to increase the risk of recurrent IUGR to a level higher than that attributable to either risk factor alone.

Birth Weight↗