Biomedical subjects
B Sanders
Publications and source records attributed to B Sanders.
Arginine in burn injury improves cardiac performance and prevents bacterial translocation.
This study examined the effects of arginine supplement of fluid resuscitation from burn injury on cardiac contractile performance and bacterial translocation after a third-degree burn comprising 43% of the total body surface area in adult rats. Before burn injury, rats were instrumented to measure blood pressure; after burn (or sham injury), paired groups of sham-burned and burned rats were given vehicle (saline), L-arginine, D-arginine, or N-methyl-L-arginine (300 mg/kg in 0.3 ml of saline 30 min, 6 h, and 23 h postburn) plus fluid resuscitation; sham-burned rats received drug only. Twenty-four hours after burn trauma, hemodynamics were measured; the animals were then killed and randomly assigned to Langendorff heart studies or to studies examining translocation of gut bacteria. Burn rats treated with vehicle, D-arginine, or N-methyl-L-arginine had well-defined cardiocirculatory responses that included hypotension, tachycardia, respiratory compensation for metabolic acidosis, hypocalcemia, cardiac contractile depression, and significant bacterial translocation. Compared with values measured in vehicle-treated burn rats, L-arginine given after burn improved blood pressure, prevented tachycardia, reduced serum lactate levels, improved cardiac performance, and significantly reduced bacteria translocation, confirming that L-arginine administration after burn injury provided significant cardiac and gastrointestinal protection. Circulating neutrophil counts fell after burn trauma and serum glucagon levels rose, but these changes were not altered by pharmacological intervention. Our finding of significantly higher coronary perfusate guanosine 3',5'-cyclic monophosphate concentration in L-arginine-treated burn rats suggests that the beneficial effects of L-arginine were mediated by nitric oxide production.
Clinical trial of the uterine thermal balloon for treatment of menorrhagia.
STUDY OBJECTIVES: To evaluate the safety and efficacy of thermal balloon endometrial ablation in women with menorrhagia, and to identify factors influencing outcome. DESIGN: Prospective, observational study (Canadian Task Force classification II-2). SETTING: Three Canadian university-affiliated teaching hospitals. PATIENTS: One hundred twenty-one women suffering from menorrhagia serious enough to make them candidates for endometrial ablation or hysterectomy. Patients without obvious structural or (pre)malignant abnormalities were included if their uterine cavities sounded to less than 12 cm, they were in good health, and had undergone hysteroscopy or pelvic ultrasound and endometrial biopsy within 6 months and had a normal Papanicolaou smear within 1 year. INTERVENTIONS: A balloon catheter was placed through the cervix and after inflation in the endometrial cavity with 5% dextrose in water, was heated to 87 +/- 5 degrees C. Two-thirds of patients avoided general anesthesia and very few required cervical dilatation to admit the 4.5-mm diameter catheter. Balloon pressures were 90 to 140 mm Hg in 13 patients; pressures between 140 and 190 mm Hg were well tolerated by the rest. Nineteen women underwent 12 minutes of therapy, and the rest had 8-minute sessions. MEASUREMENTS AND MAIN RESULTS: No intraoperative complications occurred, and minor postoperative morbidity occurred in 4% of patients. Preoperative and postoperative bleeding was assessed by pad counts and patient self-reports. The degree of dysmenorrhea was recorded similarly. A paired t test was used to compare pretreatment with posttreatment pad counts. A Wilcoxon signed rank test was employed to evaluate the effect of treatment on dysmenorrhea. The effects on outcome of several independent variables were analyzed by multiple and logistic regression. Success of the procedure was constant over the year (range 86-90%). Treatment led to significant decreases in menstrual flow, duration, and pain (p <0.0001). No significant effects of parity, uterine position or cavity depth, timing, or various endometrial-thinning regimens were found. Increasing age was significantly associated with increased odds of success (p < 0.05). Excluding the 19 women who underwent 12 minutes of therapy did not change statistical results, whereas excluding the 13 treated with balloon pressures less than 140 mm Hg improved the results. Conclusion. The facts that bleeding and dysmenorrhea were significantly reduced by thermal balloon endometrial ablation, that no intraoperative complication occurred, and that postoperative morbidity was minimal, lead us to conclude that this is potentially a safe and effective technique. Larger studies and longer follow-up are required to substantiate this impression.
Model for outcomes assessment of antihistamine use for seasonal allergic rhinitis.
BACKGROUND: Drug selection for optimal treatment of common medical conditions may be difficult and involve many diverse factors. OBJECTIVE: The efficacy, safety, quality of life, and cost of treatment of seasonal allergic rhinitis with cetirizine, chlorpheniramine, or terfenadine were compared in a prospective, two-phase, randomized, single-blind clinical trial conducted in a managed care setting. METHODS: In phase I, which lasted 2 weeks, patients were randomized to receive one of the study drugs. In phase II, which lasted 4 weeks, the initial treatment was continued unless patients were dissatisfied, in which case they could be randomly assigned to receive another study drug. In both phases pseudoephedrine could be taken as needed. Patients kept daily diaries of symptoms and costs, and study drugs were evaluated at the end of each phase for efficacy, safety, and effect on quality of life by means of a validated questionnaire. A multiattribute outcomes assessment model for formulary decision making was used to rank the antihistamines. RESULTS: Physicians' and patients' assessments in phases I and II indicated that cetirizine and chlorpheniramine were significantly more effective than terfenadine (p < 0.05). Incidence of sedation in phase I and phase II was 40.5% and 16.7% for chlorpheniramine, 11.6% and 9.8% for cetirizine, and 6.7% and 5.1% for terfenadine, respectively. At the end of phase I, 28.9% of the patients treated with chlorpheniramine, 50% of the patients treated with terfenadine, and 69.4% of the patients treated with cetirizine were satisfied with their therapy and chose not to switch their medication. Quality of life scores improved most after treatment with cetirizine and least after treatment with terfenadine. CONCLUSION: The result of this trial indicate that antihistamine selection is best made with the use of a multiattribute evaluation that includes quality of life. In this study cetirizine was favored by patients and physicians most often, followed by chlorpheniramine and then terfenadine.
Uterine Balloon Therapy for the Treatment of Menorrhagia
From June 1994 to December 1995, 116 women (mean age 39 yrs, range 27-50 yrs) who met inclusion and exclusion criteria underwent endometrial ablation with a thermal balloon system. Forty-one (35%) were treated under general and 71 (61%) under neuroleptic anesthesia. Four (3%) treatments were performed under paracervical block only. A 16-cm long, 3-mm diameter catheter with a latex balloon at its tip housing a heating element was inserted into the uterus and filled with sterile 5% dextrose in water solution (mean 10.4 ml, range 2-55 ml). The catheter was connected to a control unit that maintained the temperature at 87 ± 5° C, monitored the pressure, and terminated the treatment after 8 minutes. The starting uterine pressure was 80 to 140 mm Hg in the first 13 women and greater than 140 mm Hg in the rest. Nineteen women were treated for 12 minutes and all others for 8 minutes. Complications were endometritis (3), hematometra (2), and cystitis (1). At 6-month follow-up, after 8 minutes of treatment, persistent menorrhagia was reported by 38% and 12% of patients at less than and greater than 140 mm Hg pressure, respectively. At greater than 140 mm Hg pressure, menorrhagia was reported by 13% of women after 8 and 12 minutes of treatment. In 38 women, amenorrhea or spotting occurred in 29%, hypomenorrhea in 45%, eumenorrhea in 21%, and menorrhagia in 5%. Uterine balloon therapy is a safe and effective treatment for menorrhagia at uterine pressures of 150 to 180 mm Hg and of 8 minutes' duration.
Preparticipation physical examinations.
Preparticipation physical examinations are a prerequisite for competition at most levels of sports. This article discusses the unique opportunity that the health care team has to participate in the provision of sports assessment and screening services to a wide variety of individuals. In addition, this article reviews the purpose of the examination, organizational consideration, components of the examination, and special considerations that should be included.
Custom CAD/CAM total temporomandibular joint reconstruction system: preliminary multicenter report.
PURPOSE: The purpose was to test the outcome of a custom computer assisted design/computer assisted manufactured (CAD/CAM) total temporomandibular joint (TMJ) reconstruction system. PATIENTS AND METHODS: There were 215 patients (13 males and 202 females); the average age at reconstruction was 40.9 +/- 10.3 years (range, 15 to 77 years). There were 363 joints placed, 296 bilateral and 67 unilateral. The patients had TMJ problems for an average of 10.3 +/- 7.0 years (range, 1 to 44 years), and had undergone a mean of 5.4 +/- 4.8 (range, 0 to 28) prior unsuccessful surgeries. Preoperative and postoperative data were collected for up to 48 months using a standardized data collection format. Subjective data related to pain, function of the lower jaw, and diet, were obtained using a visual analogue scale. Objective measures of mandibular range of motion were made directly on the patient preoperatively and postoperatively. RESULTS: Preliminary analysis of these data reveals a statistically significant decrease in pain, an increase in function, and improvement in diet (P < .0001) from the preoperative measurements to 1 and 2 years postoperatively. There was also improvement in mandibular vertical range of motion. The number of previous surgeries was a strong predictor of postoperative pain, function, and diet scores, as well as of maximal interincisal opening. A life table analysis of failures indicates good durability of the prosthesis over time. CONCLUSION: These preliminary data indicate that this custom CAD/CAM total TMJ reconstruction system seems to be useful in the treatment of the multiply operated, and/or anatomically mutilated TMJ.
The measurement of psychological maltreatment: early data on the Child Abuse and Trauma Scale.
This paper describes a self-report measure, the Child Abuse and Trauma Scale, which yields a quantitative index of the frequency and extent of various types of negative experiences in childhood and adolescence. Data on this measure are presented for two large samples of college students and for a small clinical sample of subjects with a diagnosis of Multiple Personality Disorder. The strong internal consistency and test-retest reliability of the scale in the college population is documented, and its validity is attested to by demonstrating that it correlates significantly with outcomes such as dissociation, depression, difficulties in interpersonal relationships, and victimization, all of which have previously been associated with childhood trauma or abuse. The extremely high scores of the Multiple Personality subjects confer additional validity to the measure. The authors suggest that the construct of psychological maltreatment underlies the destructive elements of numerous forms of abuse and neglect, and that the scale they have developed may provide a useful index of this construct.
Management of internal derangements of the temporomandibular joint.
This article discusses the orthodontist's involvement in treating patients with complex temporomandibular joint (TMJ) disorders. It includes a review of the literature and information regarding classification, epidemiology, incidence, and diagnosis of TMJ internal derangements. Controversies in management discussed include the importance of disc position, the consequences of not repositioning the disc, and the predictability of progression of disease. Considerations regarding home care, medical care, and surgical care are also presented.
Mediation of abusive childhood experiences: depression, dissociation, and negative life outcomes.
A study of 301 college undergraduates is employed to test a causal model which proposes that dissociation and depression act as mediator variables that develop from child abuse and lead to various negative outcomes. As predicted, child maltreatment was found to be related to negative life experiences, with depression and dissociation differentially mediating the various outcomes.
Stress Proteins as Molecular Chaperones: Implications for Toxicology.
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Forced single-nostril breathing and cognition.
This experiment investigated whether forced single-nostril breathing differentially affects cognitive abilities presumed to be mediated by the left and right cerebral hemispheres. Phase I was an attempted replication of a reported sex difference in the effects of unilateral breathing on verbal versus spatial performance and Phase II was a study of breathing effects on different verbal and spatial tests. No differences associated with breathing condition were found in the replication study. In Phase II, men breathing through the right nostril scored significantly lower than men in the control condition on a letter-matching test although they did not differ significantly from men in the left-nostril condition on that test. There were no significant breathing-related differences on two spatial tests, and no differences associated with breathing condition for the women. Assessment of nostril dominance before and after cognitive testing showed that the forced-breathing exercise did not significantly alter subjects' nostril dominance. A significant left-nostril bias was found in this sample.
Is the gender difference in mental rotation disappearing?
Several investigators have used meta-analysis to compare the results of studies of gender differences on various spatial tests and have concluded that the magnitude of the gender difference in spatial ability is decreasing over time. The present study used meta-analytic techniques to compare the effect size (d) of the gender difference in 14 studies published from 1975 to 1992 which administered the Mental Rotations test to adolescents and young adults. Males scored significantly higher than females in all the studies. Analyses of the d's computed for the studies revealed that the magnitude of the gender difference on the Mental Rotations test has remained stable over time. Neither the Pearson correlation relating the d's to the publication dates of the studies nor the Z test of the linear contrast relating the publication dates of the studies to the effect sizes showed a linear change in the size of the gender difference over time. The finding of a stable gender difference on the Mental Rotations test argues against the general conclusion that the gender difference in spatial ability is decreasing.
Superior fatigue resistance of elite black South African distance runners.
Black athletes currently dominate long-distance running events in South Africa. In an attempt to explain an apparently superior running ability of black South African athletes at distances > 3 km, we compared physiological measurements in the fastest 9 white and 11 black South African middle-to long-distance runners. Whereas both groups ran at a similar percentage of maximal O2 uptake (%VO2max) over 1.65-5 km, the %VO2max sustained by black athletes was greater than that of white athletes at distances > 5 km (P < 0.001). Although both groups had similar training volumes, black athletes reported that they completed more exercise at > 80% VO2max (36 +/- 18 vs. 14 +/- 7%: P < 0.005). When corrections were made for the black athletes' smaller body mass, their superior ability to sustain a high %VO2max could not be explained by any differences in VO2max, maximal ventilation, or submaximal running economy. Superior distance running performance of the black athletes was not due to a greater (+/- 50%) percentage of type I fibers but was associated with lower blood lactate concentrations during exercise. Time to fatigue during repetitive isometric muscle contractions was also longer in black runners (169 +/- 65 vs. 97 +/- 69 s; P < 0.05), but whether this observation explains the superior endurance or was due to the lower peak muscle strength (46.3 +/- 10.3 vs. 67.5 +/- 18.0 Nm/l lean thigh volume; P < 0.01) remains to be established.
Temporomandibular joint arthroscopy: a 6-year multicenter retrospective study of 4,831 joints.
Four health outcomes (range of motion, pain, diet, and disability) were measured in six diagnostic categories (internal derangement with closed lock, internal derangement with painful click, osteoarthritis, hypermobility, fibrous ankylosis, and arthralgia) in a 6-year retrospective multicenter study of 4,831 temporomandibular joints having undergone arthroscopic surgery. After arthroscopic surgery, 91.6% of all patients had good or excellent motion; 91.3% had good or excellent pain reduction; 90.6% had good or excellent ability to maintain a normal diet; and 92% had a good or excellent reduction in disability. These health outcomes compare favorably with all other known treatments for these conditions. Also, the surgical technique was relatively free of complications (4.4%).
Sex differences in performance and hemispheric organization for a nonverbal auditory task.
Musically experienced and inexperienced men and women discriminated among fundamental-frequency contours presented either binaurally (i.e., same contour to both ears) or dichotically (i.e., different contours to each ear). On two separate occasions, males made significantly fewer errors than did females in the binaural condition, but not in the dichotic condition. Subjects with prior musical experience were superior to musically naive subjects in both conditions. The dichotic pitch task produced a left-ear advantage, which was unrelated to gender or musical experience. The results suggest that the male advantage on the binaural task reflects a sex difference in the coordination of the two hemispheres during conjoint processing of the same stimuli rather than a difference in the direction or degree of hemispheric specialization for these stimuli.
Arthroscopic treatment of temporomandibular joint locking resulting from disc derangement: two-year results.
This article reports 2-year postarthroscopic surgical treatment data for 18 subjects (17 female and 1 male) who had a diagnosis of restricted mandibular movement due to an internal derangement of the temporomandibular joint (TMJ). These subjects had been treated by an average of 2.1 +/- 1.1 doctors for their TMJ problem before seeing the surgeon for arthroscopic treatment. The subjects' mean pain score at the final time point (21 to 30 months after surgery) was decreased by 57% in usual pain intensity. Jaw function showed an average improvement of 67%. These subjects also showed a 13-mm mean increase in their maximum active opening ability at the 2-year postsurgical time point. Slight to definite clicking noises were present presurgically in 11 of 18 patients, and similar joint noises were reported in 14 of 18 patients postsurgically. The mean overall improvement was rated as 8.18 +/- 2.4, with 10 the highest possible rating. One subject rated her improvement as 0, two subjects rated their improvement as 6 out of 10. No significant morbidity was reported by the subjects as a result of their surgery.
Dissociation and childhood trauma in psychologically disturbed adolescents.
OBJECTIVE: To test the hypothesis that dissociation in adolescence is positively correlated with stress or abuse experienced earlier, the authors assessed dissociation in a heterogeneous group of disturbed adolescents and examined the relationship between the degree of dissociation and the degree of reported childhood stress, abuse, or trauma. METHOD: The subjects were 47 adolescents, 13-17 years old, who were institutionalized for periods of 1-13 weeks in a private mental hospital; 35 were girls and 12 were boys. Participants completed the Dissociative Experiences Scale and a child abuse and trauma questionnaire. The hospital records of 40 of the 47 adolescents were also available. RESULTS: Scores on the Dissociative Experiences Scale correlated significantly with self-reported physical abuse or punishment, sexual abuse, psychological abuse, neglect, and negative home atmosphere but not with abuse ratings made from hospital records. CONCLUSIONS: Together with the authors' previous work showing a relation between childhood stress and later dissociation in normal college students, these findings support the view that dissociation represents a reaction to early negative experience and places multiple personality disorder at the extreme end of a continuum of dissociative sequelae of childhood trauma. Researchers should continue to try to identify psychiatric patients with prominent dissociative characteristics or symptoms and attempt to correlate this phenomenology with negative earlier experiences.