Biomedical subjects

J F Wilson

Publications and source records attributed to J F Wilson.

At least 145 records · Page 8Linked to original sources

PubMed1992

Obesity stigma reduction in medical students.

The purpose of this study was to develop and evaluate an educational intervention designed to modify the stigma held by first-year medical students towards obese patients. The intervention, composed of video, audio and written components, was based on Petty and Cacioppo's elaboration likelihood model. Prior to the course, the medical students held largely accurate beliefs about the causes of obesity, but they still maintained negative stereotypes of the obese as lazy and lacking in self-control. Analysis of students' attitudes toward obese patients five weeks and one year after the course indicates that the intervention was effective. At the five-week assessment, students in the intervention group differed from students in the control group on six of eight measures of attitudes toward the obese. One year after the course, the intervention group was significantly more likely to rate genetic factors as important in obesity and less likely to blame the obese for their condition.

Adult↗

PubMed1992

Malignant thyroid lymphoma presenting as acute airway obstruction.

Malignant thyroid lymphoma is an uncommon form of thyroid cancer which most commonly presents in elderly women. Most patients demonstrate a rapidly enlarging mass and may show tracheal deviation on chest roentgenogram. Radioisotopic scanning of the thyroid often demonstrates a "cold" or "cool" process of decreased uptake in the affected area. There is often an underlying lymphocytic thyroiditis process noted. Unfavorable prognosis is related to extracapsular extension, blood vessel wall infiltration, diffuse architectural pattern, and cervical lymph node involvement. We present two unusual cases of thyroid lymphoma presenting with acute airway obstruction and review the literature concerning this subject. One case presented a clinical and radiographic appearance similar to a prevertebral space abscess.

Abscess↗

PubMed1992

A randomized comparison of patient-controlled versus standard analgesic requirements in patients undergoing cholecystectomy.

In the current study, 55 patients undergoing elective cholecystectomy were randomly allocated to receive postoperative analgesia (morphine sulfate) administered through either patient-controlled intravenous (PCA) or standard intramuscular (IM) routes. There were no significant differences in length of hospitalization or required dose of morphine sulfate. Patients randomized to PCA reported significantly improved subjective relief from pain and a smaller percentage of time in pain during each of the first two postoperative days. In addition, they reported less sedation and less interference with both postoperative breathing and pulmonary recovery than patients who received IM morphine. Theoretically, PCA regimens can deliver narcotic analgesia at a higher and more varied rate (with fewer side effects) compared with standard IM narcotic delivery, which is more limited by considerations of clinical doses. In PCA dosing, patients should experience less time in pain and sedation. The results of the current study support this premise.

Adult↗

PubMed1991

Endogenous gamma-aminobutyric acid tonically inhibits release of alpha-melanocyte-stimulating hormone from rat hypothalamic slices.

Release of immunoreactive alpha-melanocyte-stimulating hormone (alpha-MSH) from superfused slices of rat hypothalamus was stimulated by the gamma-aminobutyric acid (GABA) receptor antagonist, bicuculline, and inhibited by the benzodiasepine, chlordiazepoxide, an allosteric GABA receptor modulator, demonstrating the presence of tonic inhibition of alpha-MSH release by endogenous GABA in hypothalamic tissue. Chlordiazepoxide increased the effect of exogenous GABA which by inhibiting basal release of alpha-MSH demonstrated that the tonic inhibition was not maximal in the resting state.

Animals↗

PubMed1991

Anterior ischemic optic neuropathy causing blindness in the head and neck surgery patient.

Anterior ischemic optic neuropathy is an uncommon and devastating event that can result in unilateral or bilateral blindness. It has been reported as a complication of ophthalmologic or general surgical and cardiothoracic procedures as well as a spontaneous event in severe systemic disease. Aggravating intraoperative factors include anemia, hemorrhage, hypotension, preexisting small-vessel disease, and increased intraocular pressure. We present a case of anterior ischemic optic neuropathy as a complication in a 48-year-old man undergoing extensive resection of recurrent carcinoma of the head and neck. Possible contributing risk factors in our patient include preexisting hypertension, intraoperative blood loss, previous radical neck dissection with venous compromise, intraoperative head and neck edema, and the use of tightly adherent plastic bubble-type intraoperative eye protection. The possible pathogenesis of this devastating complication and recommendations for prevention and management of anterior ischemic optic neuropathy are described.

Blindness↗

PubMed1991

Psychological functioning across stages of treatment for infertility.

Psychological functioning was examined for a cross section of 104 couples in different stages of medical investigation for infertility. Couples were separated into three stages based upon the length of time they had been pursuing medical treatment for infertility: year 1, year 2, and year 3 and beyond. Emotional strain was moderately elevated during the first year, returned to more normal levels during the second year, and showed marked increases beyond year 3. Indices of marital adjustment and sexual satisfaction were stable across the first two stages but deteriorated after the third year. These data suggest that the stage of treatment may exert a major influence upon psychological functioning for infertile couples pursuing medical assistance. The results are consistent with a model of psychological strain that reflects an acute stress reaction to the initial diagnosis and treatment overlaid with a chronic strain response to longer-term treatment.

Adaptation, Psychological↗

PubMed1991

Is the dose-response relationship for local control of Hodgkin's disease obscured by lung inhomogeneity corrections?

Absence of a dose-response relationship has been reported for local control of Hodgkin's disease between 30 and 42 Gy delivered to the mantle field in definitive irradiation. These dose ranges were determined at the central ray using irregular field (IF) calculations without benefit of dosimetric correction for lung inhomogeneity. Detailed analysis was performed of dose delivered to hilar and mediastinal regions with mantle field irradiation incorporating lung inhomogeneity corrections for the indicated dose ranges using 60Co and 6 MV linear accelerator. Inclusion of lung inhomogeneity (LI) corrections revealed dose heterogeneity within the treatment volume, delivering higher total doses to hilar and lateral mediastinal regions. For a prescribed dose of 40 Gy to midline with 6 MV photons, the hila and mediastinum would receive 45 Gy with IF and LI corrections. Similar increases are observed with 60Co. Mantle field calculations should be performed with CT planning including lung inhomogeneity corrections to account for anatomic irregularity of the mediastinal contour and interposed lung. As lung inhomogeneity dosimetric data become available, conclusions drawn from clinical experience should be re-evaluated based upon location and extent of mediastinal disease involvement. Implications for treatment associated late toxicity using dose-volume histogram analysis should be considered.

Cobalt Radioisotopes↗

PubMed1991

Preschool children maintain intake of other foods at a meal including sugared chocolate milk.

Dietary self-selection was examined in 40 preschool children who were offered high-energy chocolate-flavored or plain milk with a lunchtime meal. Children aged 20-56 months were served various nutritious menus for lunch twice a week, for 8 weeks, and the chocolate milk was offered with half of the meals. The children consumed large quantities of the high-energy chocolate milk when it was offered, without decreasing their intake of other food items in the meal. Thus, significantly more energy was consumed during each of the different meals in which chocolate milk was served. These results open the possibility that, by offering palatable, high-energy drinks to preschool children at a mealtime, one might be able to increase children's caloric intake without compromising the rest of the diet at that meal. The effect of this increased caloric consumption on intake during subsequent meals, as well as the effect of repetition of the test meals, remains to be tested.

Animals↗

PubMed1991

Psychological sequelae of infertility treatment: the role of gender and sex-role identification.

Infertility has traditionally been viewed as a female problem and women have been expected to suffer greater psychological distress due to infertility. This paper investigates the nature of gender differences and sex-role identification in the psychological sequelae associated with infertility treatment. The expectation that infertile women experience higher distress levels than men was not supported by these data. No gender differences were observed in either the level of emotional strain, marital adjustment, or sexual satisfaction for the 104 couples studied. However, gender differences were apparent in factors associated with psychological distress, suggesting that while the level of strain might be comparable, the experience of infertility is different for men and women. Sex-role identification was found to have a greater relationship to the indices of distress than gender. Masculinity was associated with lower emotional strain and greater marital satisfaction for both genders and enhanced sexual satisfaction for men. Femininity was related to enhanced marital and sexual satisfaction for both genders. Gender differences and sex-role identification are discussed in the context of the unique experience of infertility.

Female↗

PubMed1991

Improved dose localization with dual energy photon irradiation in treatment of lateralized intracranial malignancies.

Dual energy photon irradiation (6 MV and 20 MV) was compared to conventional treatment planning with 6 MV photons in a lateralized intracranial malignancy. Dose volume analysis was performed of both the tumor plus a 2 cm margin (target volume, TV) and normal tissues (NT). Parallel opposed treatment using weightings of 1:1, 1.5:1, and 2:1 were compared for 6 MV photons alone or in combination with 20 MV photons. Uniform treatment of the TV was accomplished within the 60 Gy isodose. Significant differences were observed, however, in NT volumes receiving greater than or equal to 60 Gy and 45-59 Gy. Dual photon energy reduced treatment of NT volumes to greater than or equal to 60 Gy by 13% (177 cm3 vs 204 cm3 in 2:1 weighting) to 70% (147 cm3 vs 498 cm3 in 1:1 weighting) for comparable plans. Dose optimization was also performed for both 6 MV alone or in combination with 20 MV photons. Usual approaches to achieve dose lateralization with conventional isocentric techniques were applied including parallel opposed 6 MV photons ipsilaterally weighted 3.4:1 (POP), and a 110 degrees arc rotational field used to limit treatment to the eye (ARC). Dual energy photon optimized plans included a three beam parallel opposed plan (TOP) and a mixed photon ipsilateral (IPSI) approach. The technique using parallel opposed 20 MV photons and ipsilateral 6 MV photons (TOP) used beam weightings of 1.1 (contralateral 20 MVX): 1.6 (ipsilateral 6 MVX): 1 (ipsilateral 20 MVX) to achieve dose optimization. The ipsilateral approach with 6 MVX and 20 MVX (IPSI) used beam weightings of 1:1.4, respectively. All optimized plans demonstrated a 41% (120 cm3; POP) to 53% (95 cm3; TOP) improvement over parallel opposed 6 MV photons weighted 2:1 (204 cm3) in NT volume receiving greater than or equal to 60 Gy. Comparison of optimized treatment showed the IPSI plan to be superior, treating 12% of NT volume to greater than or equal to 60 Gy and 38% to 45-59 Gy; the 6 MV POP plan resulted in NT volumes of 15% and 51%, respectively, for those dose levels. Dual photon energy irradiation of lateralized intracranial malignancies allows reduction of dose to normal tissue volumes while achieving excellent coverage of the target volume. Treatment planning should be performed in all lateralized intracranial lesions to achieve dose optimization exploiting depth dose characteristics.

Brain Neoplasms↗

PubMed1991

Dosimetry of the breast for determining carcinogenic risk in mantle irradiation.

Development of secondary malignancies following treatment of Hodgkin's disease with radiation (central axis midline dose of 3600-4500 cGy) is a recognized risk, and the incidence in breast cancer has been reported to increase by a factor of 4.3 (95% confidence level 2.0 to 8.4) for patients treated with mantle irradiation. Increased incidence of breast cancer has also been shown in atomic bomb survivors, women who underwent multiple fluoroscopic examinations, and women treated for postpartum mastitis. The dose response, however, for radiation dose above 1000 cGy is virtually unknown. Quantitative analysis of carcinogenesis after radiation is exacerbated by the large dose gradient across the breast (300-4200 cGy for midline doses of 4000 cGy), large individual variation in breast size and treatment field position. We have developed differential dose volume histograms calculated using a 3-dimensional (Eg TAR) algorithm as a potential tool for retrospective and prospective epidemiological evaluation. The breast volume forms a bimodal distribution with respect to dose and with further analysis other quantities, such as mean dose and integral dose, can be calculated from the histograms. Using the mean dose, the linear model for carcinogenesis predicts an increased incidence of secondary breast cancer by a factor of 11.6 and 9.6 for the left and right breast, respectively. The dose calculations has been corrected for inhomonogenities 3-dimensionally and test of the accuracy has been included.

Breast Neoplasms↗

PubMed1991

Physical and emotional stress associated with components of the infertility investigation: perspectives of professionals and patients.

OBJECTIVE: The present study examined patients', nurses', and physicians' perceptions of the physical and emotional difficulty of infertility treatment. DESIGN: A mail survey method was used. PATIENTS, PARTICIPANTS: Participants included 26 patients, 76 nurses, and 71 physicians from infertility clinics in the United States and Canada. MAIN OUTCOME MEASURES: A rating scale measured the physical and emotional difficulty level of 36 components from the infertility investigation. RESULTS: Nurses rated the emotional and physical distress of patients higher than did patients and physicians, whereas patients rated their distress higher than did physicians. Older nurses and physicians inferred lower levels of physical and emotional distress than did their younger counterparts. A greater breadth of experience with infertility treatments was associated with higher ratings of emotional distress by nurses and lower ratings by physicians. CONCLUSIONS: Patients, nurses, and physicians perceive infertility treatment from unique vantage points creating differences in perceptions that have implications for patient care. Factors including era of professional training, stage of life, and changes resulting from advancing technology are viewed as influencing health care professionals' perceptions of infertility distress.

Adult↗

PubMed1991

Characteristics of NMDA receptors that stimulate release of hypothalamic alpha-MSH.

N-methyl-D-aspartic acid (NMDA) 10(-4) M stimulated release of immunoreactive alpha-melanocyte-stimulating hormone (alpha-MSH) from superfused slices of rat hypothalamus through receptors which shared common features with other central NMDA-type glutamate receptors. The receptors possessed inhibitory sites for both Mg2+ and ketamine; basal and NMDA-stimulated alpha-MSH release was reduced by high (5 mM) Mg2+ ion concentrations and by 10(-4) M ketamine, whilst use of Mg(2+)-free media led to a prolongation of the NMDA-stimulated response. The receptors were also shown to possess an allosteric glycine site. The glycine site agonist D-serine 10(-4) M potentiated basal and NMDA-stimulated alpha-MSH release whilst the antagonist, 7-chlorokynurenic acid 10(-4) M, reduced NMDA-stimulated release, an effect which was partially reversed by 10(-4) M D-serine.

Animals↗

PubMed1991

Physicians' psychologic reactions to malpractice litigation.

A questionnaire investigating the psychologic sequelae of malpractice litigation was administered to sued and nonsued physicians through a major malpractice insurer in a rural southern state. Factor analysis showed clusters of symptoms, including psychologic trauma, job strain, shame/doubt, and active coping. Psychologic stress decreased with time (but did not return to baseline after 2 years), with winning a case, and with increased age. Stress was increased among those with cases pending or multiple suits. Female physicians used more active coping strategies, and being in a high-risk specialty led to greater job strain and active coping, regardless of litigation experience. Malpractice litigation is a major life trauma that should be dealt with as any other trauma, including use of positive coping strategies such as knowledge of the psychologic sequelae, cognitive reframing, and collegial and personal support systems.

Adaptation, Psychological↗

PubMed1991

A continuum model of elephant trunks.

A continuum model is presented that relates the trunk parameters of loading, geometry, and muscle structure to the necessary conditions of static equilibrium. Linear theory for stress-strain behavior is used to describe an elephant trunk for an incremental displacement as the animal slowly lifts a weight at the trunk tip. With this analysis and experimental values for the trunk parameters, the apparent trunk stiffness Ea is estimated for the living animal. For an Asian elephant with a maximum compression strain of 33 percent, Ea is of the order of 10(6) N/m2. The continuum model is quite general and may be applied to similar nonskeletal appendages and bodies of other animals.

Animals↗

PubMed1991

Specific cellular and humoral immune responses in patients with different long-term courses of alveolar echinococcosis (infection with Echinococcus multilocularis).

Alveolar echinococcosis is a serious and often fatal disease of humans that in most cases can be efficiently cured only by complete surgical resection of the Echinococcus multilocularis lesion. In a few patients, however, a spontaneous cure of the disease has been observed by demonstrating the presence of lesions with dead metacestodes. The present study shows a comparative analysis of the cellular (lymphoproliferative assay) and humoral (antibody activity in an Em2 enzyme-linked immunosorbent assay [ELISA] and immunoblotting) immune response in 1) patients who were cured by a radical surgical resection of the E. multilocularis parasite lesion, 2) patients who had a partial surgical resection of the parasite lesion, 3) patients who had a non-resectable alveolar echinococcosis, and 4) patients who were shown to be spontaneously cured and had lesions with dead parasites. The in vitro lymphoproliferative response to E. multilocularis antigen stimulation was very high in cured patients who had radical surgery or in patients with lesions containing dead parasites, but it was significantly lower in patients who had partial surgical or no resection. Antibody concentrations in the Em2-ELISA were high in patients who had incomplete or no surgery, and low or negative in cured patients who had radical surgery or in patients with lesions containing dead parasites. Immunoblot analysis of patient sera revealed a consistent antibody banding pattern among cured patients with radical surgery and patients with incomplete or no surgery, whereas cured patients with lesions containing dead parasites showed a very faint antibody pattern.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1991

Performance of techniques used to detect drugs of abuse in urine: study based on external quality assessment.

Twenty-five samples of lyophilized urine from the U.K. External Quality Assessment Scheme for Drugs of Abuse were analyzed by an average of 95 laboratories between April 1987 and December 1989. Samples contained mixtures of analytes and included replicated concentrations of morphine, methadone, amphetamine, and cocaine at 0, 1, 2, and 5 mg/L and of benzoylecgonine at 0, 0.4, 1, 2, and 4 mg/L. Some chromatographic techniques were inadequate for detecting morphine, amphetamine, cocaine, and benzoylecgonine at the lower concentrations of analytes studied: gas-liquid chromatography was least sensitive for morphine; in-house thin-layer chromatography (TLC) was least sensitive for the other analytes. Few significant differences in specificity were detected between techniques, although significant interference from structurally related compounds was demonstrated in assays of morphine, methadone, and amphetamine. Exceptions were the Boehringer (BCL) test for opiates and TLC applied to amphetamine and benzoylecgonine, which demonstrated considerable lack of specificity.

Amphetamine↗

PubMed1990

Ionic, neuronal and endocrine influences on the proopiomelanocortin system of the hypothalamus.

Increasing evidence supports a neurotransmitter or a neuromodulator action for peptides derived from proopiomelanocortin in the hypothalamus. Peptide release involves sodium, potassium and calcium ion channels and is dependent on the presence of extracellular calcium ions at the time of depolarisation of neuronal membranes. Dopaminergic and gamma-aminobutyric acid-containing neuronal systems inhibit POMC-derived peptide release from the hypothalamus through D2-dopamine and GABAA receptors, respectively. Serotoninergic mechanisms exert a biphasic effect on peptide release being directly stimulatory at low concentrations of serotonin and indirectly inhibitory at higher concentrations via interactions with the endogenous dopaminergic system. Cholinergic and glutamergic drugs stimulate peptide release through nicotinic and N-methyl-D-aspartate receptors, respectively. Finally, circulating steroids regulate the hypothalamic POMC system with testosterone stimulating POMC gene expression whilst oestradiol and glucocorticoids induce an inhibitory control.

Animals↗