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Biomedical subjects

A L Wright

Publications and source records attributed to A L Wright.

At least 91 records · Page 5Linked to original sources
PubMed1991

Quantification of allergic and irritant patch test reactions using laser-Doppler flowmetry and erythema index.

The laser-Doppler blood flow and erythema index were assessed in 16 patch test reactions caused by irritants (1% aq. sodium lauryl sulphate and 1% aq. benzalkonium chloride) and in 13 varied allergic reactions, at 2 or 4 days. Both irritant and allergic responses produced statistically significant increases in laser-Doppler flow index and erythema index compared to control sites (p less than 0.05 or less, using the Wilcoxon rank-sum test). A disproportionately greater increase in erythema index than in laser-Doppler flow was seen in mild irritant reactions, compared to allergic, though the two could not be reliably distinguished by these tests. 2 non-allergic nickel sulphate sites produced an increase in both blood flow and erythema without any clinical change. Petrolatum alone produced no significant change in either measurement. The laser-Doppler flow showed an overall correlation with the erythema index (product moment method; r = 0.55, p less than 0.001), but there was little correlation between these indices and patch test reactivity as judged clinically by conventional scoring. Generally, allergic and irritant patch test reactions could not be differentiated on the basis of laser-Doppler flow or erythema index. However, the disproportionate increase in erythema index over laser-Doppler flow index for mild irritant responses warrants further study in other irritant models.

Allergens↗
PubMed1991

Initial airway function is a risk factor for recurrent wheezing respiratory illnesses during the first three years of life. Group Health Medical Associates.

We recently reported a significant relationship between lung function measured prior to any lower respiratory tract illness and subsequent wheezing illnesses during the first year of life (N Engl J Med 1988; 319:1112-7). Follow-up has continued for this group of infants during the second and third years of life. When compared with never wheezers, infants who wheezed during the first year of life and had at least one additional lower respiratory illness had 22% lower initial levels of an indirect index of airway conductance derived from the shape of tidal breathing curves (p less than or equal to 0.01), 22% lower respiratory conductance (p less than or equal to 0.05), 25% lower maximal flows at the end-expiratory point (p less than or equal to 0.01), and 10% lower functional residual capacity (p less than or equal to 0.05). Infants who wheezed only once during the first 3 yr of life or who started wheezing during the second year of life had normal tidal breathing curves but significantly lower maximal expiratory flows (p less than or equal to 0.05). Their functional residual capacity was also lower than that of never wheezers (p less than or equal to 0.05). We conclude that diminished initial airway function may be a predisposing factor for recurrent wheezing respiratory illnesses starting in the first year of life. Infants who will have only one wheezing respiratory illness or who will start wheezing after the first year of life seem to have lower levels for some but not for all lung function tests performed in this study.

Age Factors↗
PubMed1990

On the creation of 'problem' patients.

Recent debates regarding clinical transactions oppose a macro-level approach which emphasizes political, economic and institutional forces, and those analysts who consider patient perceptions regarding illness to be major influences on the outcome of clinical encounters. This paper utilizes both approaches to illuminate the interactions between medical personnel and 'problem patients'. The macro-level approach draws attention to the way power is negotiated and expressed in clinical interactions, and to medicalization that gives priority to medical values and condemns patients who do not act in accord with these values. The patient belief approach explores one of the major weapons in the struggle for control, the disease model of illness. Use of both approaches permits a better understanding of clinical medicine in these problematic interactions.

Adult↗
PubMed1990

Prehospital cardiac arrest: the impact of witnessed collapse and bystander CPR in a metropolitan EMS system with short response times.

OBJECTIVE: Numerous studies have shown initiation of bystander CPR to significantly improve survival from prehospital cardiac arrest. However, in emergency medical services (EMS) systems with very short response times, bystander CPR has not been shown to impact outcome. The purpose of this study was to determine the effect of bystander CPR on survival from out-of-hospital cardiac arrest in such a system. DESIGN: Prehospital, hospital, and death certificate data from a medium-sized metropolitan area were retrospectively analyzed for adult, nontraumatic cardiac arrest during a 16-month period. RESULTS: A total of 298 patients met study criteria. One hundred ninety-five arrests (65.4%) were witnessed, and 103 (34.6%) were unwitnessed. Twenty-five witnessed victims (12.8%) were discharged alive, whereas no unwitnessed victims survived (P less than .001). Patients suffering a witnessed episode of ventricular fibrillation/tachycardia (VF/VT) were more likely to survive (21.9%) than were other patients (2.0%, P less than .0001). Among witnessed patients, initiation of bystander CPR was associated with a significant improvement in survival (20.0%) compared with the no-bystander CPR group (9.2%, P less than .05). Bystander CPR was also associated with improved outcome when witnessed patients with successful prehospital resuscitation were evaluated as a group; 18 had bystander CPR, of whom 13 (72.2%) survived compared with only 12 of 38 patients with no bystander CPR (31.6%, P less than .01). CONCLUSION: Our data revealed improved survival rates when bystander CPR was initiated on victims of witnessed cardiac arrest in an EMS system with short response times.

Adult↗
PubMed1990

Cost-effectiveness analysis of paramedic emergency medical services in the treatment of prehospital cardiopulmonary arrest.

STUDY OBJECTIVES: 1) Identification of marginal costs associated with prehospital resuscitation of cardiopulmonary arrest; 2) Determination of cost effectiveness for such resuscitation; and 3) Comparison of cost effectiveness of paramedic care with selected other medical interventions. DESIGN: Retrospective review of 190 cases of out-of-hospital cardiac arrest. SETTING: City limits of a midsized southwestern city. The events studied took place outside of medical facilities. TYPE OF PARTICIPANTS: Victims of out-of-hospital cardiac arrest for whom the EMS system was activated by a 911 telephone request for emergency medical assistance. MEASUREMENTS AND MAIN RESULTS: The cost, including training, personnel, equipment, and response time maintenance, per year of life saved was found to be $8,886.00 for paramedic care. This result was compared with published cost-effectiveness figures for heart transplantation, liver transplantation, bone marrow transplantation, and chemotherapy for acute leukemia. Paramedic care was more cost effective, as measured by cost per year of life saved, than organ transplantation and chemotherapy for acute leukemia. CONCLUSION: Out-of-hospital treatment by paramedics of cardiopulmonary arrest is more cost effective than heart, liver, bone marrow transplantation, or curative chemotherapy for acute leukemia.

Arizona↗
PubMed1990

Hypothyroidism in textile workers.

Four cases of overt hypothyroidism, three of whom were men in their early forties, had occurred over a period of 6 years at a textile factory where thiourea and resorcinol were used in the finishing departments. A follow-up survey of 189 men and 48 women (44 per cent of employees) revealed 12 new cases of varying grades of hypothyroidism, categorized after the system proposed by Evered. These included a case of mild hypothyroidism in a male worker, who subsequently received thyroid hormone replacement therapy as a hospital out-patient. A full occupational hygiene survey was carried out to determine possible sources of exposure to thiourea and resorcinol. Although we were unable to demonstrate a statistically significant occurrence of biochemically and immunologically detectable disturbances in thyroid function among this workforce, we did note that three of the original index cases and several of those workers with varying degrees of minor dysfunction in the follow-up study seemed to cluster in locations where exhausted fumes could accumulate.

Adult↗
PubMed1990

Dysplastic naevi in association with partial deletion of chromosome 11.

A patient is reported who developed dysplastic naevi at an early age. He also suffered from a syndrome including Wilms' tumour, aniridia, mental retardation and diabetes mellitus in association with an interstitial deletion of the short arm of chromosome 11. It is suggested that genetic factors may be important in sporadic as well as familial cases of the dysplastic naevus syndrome.

Adult↗
PubMed1990

An immunophenotypic study of lichen nitidus.

Skin biopsies from three patients with lichen nitidus were studied using a battery of monoclonal antibodies against cells in the dermal infiltrate. In each case the findings were identical with a marked excess of CD4+ cells over CD8+ cells and the presence of large numbers of CD1+ cells. These results are very similar to those seen in lichen planus reinforcing the association between these two conditions.

Antibodies, Monoclonal↗
PubMed1990

Malignant melanoma at sites of therapeutic X-irradiation.

Two patients are reported in whom malignant melanoma developed at sites of low-dose superficial X-ray therapy given for treatment of benign dermatoses. No causal link has been established between melanoma and X-irradiation, but previous reports of a possible association are reviewed. The probably importance of ultraviolet exposure after X-irradiation in such patients is emphasised.

Adult↗
PubMed1990

Reticulate pigmentation due to bleomycin: light- and electron-microscopic studies.

An unusual case of extensive reticulate pigmentation due to bleomycin is reported. Light- and electron-microscopic studies showed a marked increase of melanin pigment in the basal keratinocytes and a number of melanophages in the upper dermis. The number of melanocytes appeared to be normal. Electron microscopy also revealed damage to subcellular organelles. The increase in pigmentation is thought to be a consequence of this focal damage.

Bleomycin↗
PubMed1990

Effect of occupational lead exposure on serum 1,25-dihydroxyvitamin D levels.

The effects of lead exposure on serum 1,25-dihydroxyvitamin D levels and calcium homeostasis have been studied in 63 males occupationally exposed to the metal in the UK. The exposure indices used were blood lead, reflecting short-term exposure, and an in vivo X-ray fluorescence measurement of tibia lead which reflects cumulative lead exposure. Serum 1,25-dihydroxyvitamin D levels were higher than those in a referent population, who were non-occupationally exposed to lead, and were correlated with both blood lead and tibia lead. Multiple regression analysis suggested that blood lead was the variable responsible for the increase in serum 1,25-dihydroxyvitamin D. There were no other abnormalities in calcium metabolism associated with the degree of lead exposure.

Alanine↗
PubMed1990

Scarring alopecia in psoriasis.

Scalp biopsies were taken from 3 patients with a scarring alopecia associated with severe scalp psoriasis. The histological findings in each case showed inflammatory destruction of the infundibular region of the hair follicle. The similarity of these changes in each case strongly suggests an association with the psoriasis.

Adult↗
PubMed1990

AgNORs in benign, dysplastic, and malignant melanocytic skin lesions.

Nucleolar organizer regions (NORs) are loops of DNA situated on the short arms of acrocentric chromosomes 13, 14, 15, 21, and 22; they can be demonstrated in formalin-fixed paraffin-embedded sections by a one-step silver technique, the resulting black structures being termed AgNORs. We have applied the technique to 30 benign "banal" nevi (BN), 30 dysplastic nevi (DN), and 30 malignant melanomas (MM). AgNORs in 200 nuclei were scored and the means calculated. Counts were as follows: BN showed a mean of 1.3 AgNORs per nucleus within a range of 1.1-1.6; DN showed a mean of 1.2 within a range of 1.0-1.6; and MM showed a mean of 2.1 within a range of 1.2-4.2. A significant difference existed between counts for MM and those for BN and DN, despite some overlap. There was no statistically significant difference between BN and DN. Although still within the field of research, the AgNOR technique may prove to be of value in helping to differentiate MM from DN, but is unlikely to be of help in separating DN from BN.

Cell Nucleus↗
PubMed1989

Breast feeding and lower respiratory tract illness in the first year of life. Group Health Medical Associates.

OBJECTIVE: To assess the relation between breast feeding and subsequent experience of lower respiratory tract illness. DESIGN: Prospective (from well child visits) and retrospective (from maternal recall) study of breast feeding and prospective assessment by paediatricians of lower respiratory tract illness in infants during first year of life. SETTING: Health maintenance organisation. PARTICIPANTS: Over 1000 infants who were healthy at birth and whose parents used the paediatricians of a local health maintenance organisation. MAIN OUTCOME MEASURES: Duration of breast feeding and type of lower respiratory tract illness (wheezing and non-wheezing) at different age intervals during the first year of life. RESULTS: Breast feeding was associated with a decreased incidence of wheezing illnesses only in the first four months of life. Interactions existed between breast feeding and sharing a room, being Mexican American, and being a boy. Multivariate techniques showed that after controlling for a variety of factors children who received minimal breast milk had a greater risk of early wheezing illnesses; the risk was further increased by simultaneous exposure to sharing a room. CONCLUSION: Breast feeding seems to protect against wheezing respiratory tract illnesses in the first four months of life, particularly when other risk factors are present.

Breast Feeding↗
PubMed1989

Sociocultural factors in puerperal infectious morbidity among Navajo women.

From 1980 to 1982, a sample of 968 pregnant Navajo women in New Mexico was enrolled in a prospective study of biologic and sociocultural factors in puerperal infectious morbidity. Past studies have independently implicated both genital infection and psychosocial stressors in perinatal complications, but, to the authors' knowledge, no previous work has concurrently investigated the interactive effects of genital pathogens and psychosocial processes. Endocervical cultures for Mycoplasma hominis and Chlamydia trachomatis were obtained during prenatal visits, and structured interviews were conducted assessing social support and the degree of cultural traditionality, in this context a proxy measure of acculturative stress. The incidences of postpartum fever, endometritis, and premature rupture of membranes were significantly associated with the concurrence of two factors: the presence of genital tract M. hominis and a highly traditional cultural orientation. When demographic and conventional obstetric risk factors were controlled for, women with both M. hominis and high traditionality experienced infectious complications at a rate twice that of women with either factor alone. Among the plausible explanations for this result is the possibility that acculturative stress undermines physiologic resistance to infectious genital tract disease.

Adolescent↗
PubMed1989

The Tucson Children's Respiratory Study. I. Design and implementation of a prospective study of acute and chronic respiratory illness in children.

The Tucson Children's Respiratory Study, Tucson, Arizona, has been established as a long-term, longitudinal, prospective study of the risk factors for acute lower respiratory tract illnesses in early childhood and for chronic obstructive airways disease in later life. A total of 1,246 newborns were enrolled into the study between May 1980 and January 1984, representing 78% of eligible infants. Cord blood for immunologic studies, neonatal blood specimens for blood counts and differentials, and blood specimens at nine to 15 months of age for immunologic studies, blood counts, and differentials have been obtained on the majority of enrolled children. Pre-illness physiologic and more detailed immunologic studies have also been done on large subgroups of subjects. The majority of lower respiratory tract illnesses suffered by these children in the first three years of life have been assessed in detail for etiologic agents by means of culture and serologic techniques; 1,052 illnesses have been evaluated thus far. The type of illness and nature of etiologic agents are very similar to those reported in other epidemiologic studies. Thus, this group of enrolled infants and their family members constitute an appropriate population for the long-term study of risk factors for acute and chronic respiratory disorders.

Acute Disease↗