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Biomedical subjects

B Powers

Publications and source records attributed to B Powers.

At least 19 recordsLinked to original sources
PubMed1997

One-stage reconstruction of partial laryngopharyngeal defects.

Advanced-stage lesions of the hypopharynx or tongue base often involve the larynx. The difficulty of reconstructing large partial laryngopharyngeal defects can result in total laryngectomy being performed to avoid the assumed problems with aspiration. This article describes the first reported experience using the pectoralis musculocutaneous flap for primary one-stage reconstruction of laryngopharyngeal defects following resection of advanced-stage lesions, to reconstruct both the laryngeal and the pharyngeal components of the defect. In this group of 21 patients, there were 16 with hypopharyngeal and 5 with tongue base cancers. Two had received prior treatment, and all received some form of postoperative radiotherapy and/or chemotherapy. Six patients experienced complications, including two fistulae, three wound infections, two myocardial infarctions, and one colon perforation. There were no instances of stenosis of the reconstructed segment. The length of hospitalization ranged from 9 to 60 days, the average being 17 days. Forty-seven percent (21) of the patients were not tolerating an oral diet at the time of discharge. However, 15 patients (71%) ultimately were eating by mouth, with 13 (62%) achieving an oral intake of liquids and solids. This analysis supports the hypothesis that the pectoralis major musculocutaneous flap is an effective one-stage primary reconstruction technique for laryngopharyngeal defects in patients either who have received prior therapy or who will receive postoperative therapy.

Aged↗
PubMed1997

A competency-based model of child depression: a longitudinal study of peer, parent, teacher, and self-evaluations.

In a two-wave longitudinal study of third and sixth graders (N = 617), we obtained self-reports of depression and peer, teacher, parent, and self-reports of competence in five domains: academic, social, attractiveness, conduct, and athletic. Competency evaluations by others predicted change in self-perceived competence over time for girls, but not for boys. Depression predicted change in self-perceived competence over time for boys but not for girls. Among girls, the relative importance of parent, teacher, and peer appraisals shifted from third to sixth grade. For both boys and girls, self-perceptions of competence predicted change in depression scores over time. Furthermore, self-perceived competencies mediated the relation between competency appraisals by others and children's self-reported depression. Results are interpreted in light of a competency-based model of child depression.

Adolescent↗
PubMed1997

Nurse managed occupational health services without on-site clinical care delivery: a case example.

1. In this program management/community network model of occupational health services, the occupational health nurse is responsible for managing program development and implementation, with vendors providing the clinical services. 2. Occupational health nurses' primary areas of responsibility are occupational health, disability case management, ergonomics, and health promotion. 3. Successful management of program outcomes requires the occupational health nurse to continually assess employee/business needs, maintain communication with employees and management, and partner with the environmental, health, and safety team, other functional work groups, and vendors. 4. Effective management of contracts becomes critical to the process beginning with clear service requirements through the delivery of quality services.

Ambulatory Care Facilities↗
PubMed1996

Clinical and manometric results of laparoscopic partial (Toupet) and complete (Rosetti-Nissen) fundoplication.

UNLABELLED: It is unclear whether a partial or complete gastric fundoplication done laparoscopically will offer the best control of reflux with the fewest side effects. Prospective evaluation of laparoscopic Rosetti-Nissen (360) and Toupet (180) fundoplication was performed with assessment of clinical and manometric data. METHODS: Patients with severe gastroesophageal reflux referred for surgical correction underwent preoperative motility and upper endoscopy. A Rosetti-Nissen or Toupet fundoplication was then performed laparoscopically. Short gastrics were not divided. No bougie was used in the Toupet, which was sutured intracorporeally. A 2-cm, loose, floppy wrap about a 50-Fr bougie was performed in the Nissen. Eleven patients underwent Rosetti-Nissen and 11 Toupet fundoplication. Mean ages, duration symptoms, weight, and baseline LES, were not different. Preop esophagitis grades were similar, as were Visick Scores and presence of dysphagia. RESULTS: Visick scores at 6 months were better in the Toupet group than the Rosetti-Nissen (P = 0.07). Persistent Dysphagia in four, Gas-Bloat in two, and Odynophagia in one within the Rosetti-Nissen group accounted for the difference, and were not seen in Toupets. LES pressures differed significantly pre and postop (P < 0.001). The change in LES pressure was significantly different between Toupet and Rosetti-Nissen (chart). Seven patients had postop 24-h pH tests; all had no reflux. Three Rosettis have required revision to Toupet, with resolution of their symptoms. CONCLUSIONS: In patients with severe GERD, laparoscopic Toupet and Rosetti-Nissen control symptoms and esophageal pH similarly. LES pressures are higher postop in the Rosetti-Nissen. Dysphagia and gas-bloat are more prevalent in the Nissen group. Laparoscopic Toupet fundoplication may be superior to Rosetti-Nissen in reducing the frequency of side effects frequently associated with antireflux surgery, yet with equal control of reflux.

Adult↗
PubMed1996

Modeling causal relations between academic and social competence and depression: a multitrait-multimethod longitudinal study of children.

The authors obtained self-reports, peer nominations, teacher ratings, and parent reports of depression and social and academic competence on 490 3rd graders and 455 6th graders near the beginning and end of the school year. Confirmatory factor analysis and structural equation modeling revealed that (a) measures showed significant convergent and discriminant validity; (b) within-wave correlations between constructs were large and significant, although the depression-social competence correlation was larger than the depression-academic competence correlation; (c) the cross-wave stability of all constructs was remarkably high; and (d) social competence at Wave 1 predicted depression at Wave 2 for 6th graders after controlling for depression at Wave 1. Depression did not predict change in either academic or social competence over time. Implications for competence-based and failure-based models of child depression are discussed.

Achievement↗
PubMed1992

Thrombocytopenia post liver transplantation. Correlations with pre-operative platelet count, blood transfusion requirements, allograft function and outcome.

This study reports that thrombocytopenia is a universal phenomenon post hepatic transplantation. In 53 consecutive adult patients undergoing liver transplantation the platelet count fell by a mean of 63% (157 x 10(9)/l to 50 x 10(9)/l). The platelet count reached a nadir at Day 5 post-transplant but returned to pre-operative levels by Day 14. Non-parametric regression analysis found that pre-operative platelet count, blood transfusion requirements and maximum post-operative ALT values were independent predictors of the percentage fall in platelet count. No correlation was seen with length of graft cold ischaemic time or the use of University of Wisconsin (UW) solution. The nadir day correlated with maximum post-operative bilirubin and ALT, graft ischaemic time and use of UW solution. Maximum post-operative ALT was also an independent predictor of nadir platelet count. It was observed that patients who did not survive the hospital admission had lower post-operative platelet counts and these did not return to pre-operative levels by Day 14. The percentage fall in platelet count was an independent predictor of survival. Severe thrombocytopenia was associated with cerebral haemorrhage in 3 patients. This report provides evidence that allograft dysfunction (maximum post-operative bilirubin and/or AST/ALT) was the most consistent independent predictor of the nadir platelet count, nadir day and percentage fall in platelet count post liver transplantation although the exact mechanism(s) of the platelet changes remain uncertain.

Blood Transfusion↗
PubMed1988

Benign solitary schwannoma of the foot. A case report and review of the literature.

Benign solitary schwannomas of the foot are a rare occurrence; only four cases have been previously reported. A schwannoma associated with the medial plantar nerve present for more than 40 years before the onset of symptoms was diagnosed in a 73-year-old man. Excision of the mass, with preservation of the involved nerve, was possible and successfully relieved symptoms.

Aged↗
PubMed1982

Thymoma detection by mediastinal CT: patient with myasthenia gravis.

The precise role of computed tomography (CT) in evaluating the mediastinum for thymomas in patients with myasthenia gravis is not defined. The only published CT accuracy assessment reports a false-positive rate of 90%. Mediastinal CT was performed in 23 consecutive unselected patients with myasthenia gravis who underwent thymectomy independent of their neurologic status or diagnostic imaging results. Four patients had discrete thymomas; all were detected by CT. Conventional chest radiography and tomography were positive in three and falsely negative in one. In the remaining 19 patients with a normal or atrophic thymus or microscopic hyperplasia, CT was falsely positive in two; conventional chest radiography and tomography were falsely positive in three. Mediastinal CT is an accurate technique for evaluation of thymoma in patients with myasthenia gravis.

Adolescent↗
PubMed1980

Survival of Campylobacter fetus subsp. jejuni in biological milieus.

To provide new information on the epidemiology and pathophysiology of human infection with Campylobacter fetus subsp. jejuni, we studied its survival in several milieus. Standard inocula of organisms were placed in hydrochloric acid, human bile and urine, bovine milk, or stream water and kept at 4, 25, or 37 degrees C; viable organisms were then counted. Stools from humans infected with Campylobacter were similarly tested. Survival in acid was pH and time dependent, with 7-log kill within 5 min in solutions at pH 2.3. Organisms multiplied in bile at 37 degrees C and survived for 2 months. Organisms survived better in feces, milk, water, and urine kept at 4 degrees C than they did in these milieus at 25 degrees C. Maximal viabilities of Campylobacter organisms kept at 4 degrees C were 3 weeks in feces, 3 weeks in milk, 4 weeks in water, and 5 weeks in urine. Study results suggest that when these milieus are contaminated with C. fetus subsp. jejuni, they may be significant environmental reservoirs.

Animals↗
PubMed1979

Cervical spine trauma: the common combined conditions.

The two most common groups of combined traumatic conditions of the cervical spine are hyperextension and hyperflexion fracture-dislocations. In a series of 400 patients with fractures and/or dislocations of the cervical spine, 25% had hyperextension and 19% hyperflexion fracture-dislocations. A computer analysis of the cases revealed that there are five distinct types of hyperextension and four types of hyperflexion fracture-dislocations. Each of the types is considered as to incidence, causes, mechanism of injury, and roentgen and differential diagnosis.

Cervical Vertebrae↗
PubMed1979

Traumatic anterior atlanto-occipital dislocation.

The five cases of atlanto-occipital dislocation reported in the world literature are reviewed, and four additional cases are presented, including two survivors. The pathological anatomy of this potentially catastrophic injury and its management are briefly discussed. Because immediate recognition of the atlanto-occipital dislocation is critical to proper treatment and because the neurological findings are extremely varied, a new radiographic criterion for its identification has been developed.

Adult↗
PubMed1972

Sexual receptivity: facilitation by medial preoptic lesions in female rats.

Lesions in the medial preoptic area of ovariectomized female rats reduced the quantity of estrogen needed to induce sexual receptivity in these animals. In addition, the number of days over which receptive behavior could be elicited after a single initial estrogen injection and with subsequent daily progesterone treatment was significantly increased by lesions in the medial preoptic area. These findings support the view that estrogen acts to reduce an inhibitory action that is tonically exerted by the medial preoptic area on pathways mediating estrous behavior.

Animals↗
PubMedDate not supplied

A phase II trial testing the thermal dose parameter CEM43 degrees T90 as a predictor of response in soft tissue sarcomas treated with pre-operative thermoradiotherapy.

We prospectively evaluated whether delivering a thermal dose of > 10 cumulative equivalent minutes at 43 degrees C to >90% of the tumour sites monitored (CEM43 degrees T90) would produce a pathologic complete response (pCR) in > 75% of high-grade soft tissue sarcomas treated pre-operatively with thermoradiotherapy. The impact of thermal dose on local failure (LF), distant metastasis (DM), and toxicity was also assessed. Thirty-five patients > or = 18 years old with grade 2 or 3 soft tissue sarcomas accessible for invasive thermometry were enrolled on the protocol. All patients received megavoltage external beam radiotherapy (RT) in daily fractions of 1.8-2.0 Gy, five times a week, to a median total dose of 50 Gy and an initial hyperthermia treatment (HT) of I h duration utilizing the BSD 2000 with Sigma 60 or MAPA applicators at frequencies of 60-140 MHz. Further HT was given for patients with CEM43 degrees T90 > 0.5 after initial HT ('heatable' patients), twice a week to a maximum of 10 HT or CEM43 degrees T90 > 100. Of the 35 patients entered, 30 had heatable tumours, one of which was inevaluable for pCR or LF as the patient died of DM prior to surgery, leaving 29 evaluable patients. Of these 29 patients, 15 (52%) had a pCR (95% CI: 37-73%), significantly less than the projected rate of > or = 75% (p = 0.02). Of the 25 heatable tumours that achieved CEM43 degrees T90 > or = 10, 14 (56%) had a pCR (95% CI: 39-78%) significantly less than the projected rate (p = 0.06). Three of the 29 patients (10%) with heatable tumours had a LF, versus 1/5 unheatable tumours (p = 0.48). Fourteen of the 30 patients (47%) with heatable tumours developed DM, versus 2/5 unheatable tumours (p = 1.00). Ten of the 30 patients (33%) with heatable tumours developed treatment-induced toxicity. Thus, no correlation of thermal dose with histologic response was observed. Prospective control of CEM43 degrees T90 failed to achieve the projected pCR rate following pre-operative thermoradiotherapy for high-grade soft tissue sarcomas, despite excellent local control. Possible explanations for this outcome are discussed.

Adult↗