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Biomedical subjects

J M Powell

Publications and source records attributed to J M Powell.

At least 19 recordsLinked to original sources
PubMed2001

Self-report of extent of recovery and barriers to recovery after traumatic brain injury: a longitudinal study.

OBJECTIVE: To examine the perspective of survivors of traumatic brain injury (TBI) regarding the extent and nature of their recovery over time. DESIGN: Inception cohort, longitudinal study. SETTING: Level I trauma center. PARTICIPANTS: One hundred fifty-seven consecutively hospitalized individuals with TBI (mean age, 36.1 yr; 80% men) with a broad range of injury severity. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Participants reported the extent of their recovery and barriers to full recovery at 1, 6, and 12 months. RESULTS: Participants reported a median return to normal at the 3 follow-up times of 65%, 80%, and 85%. After 1 month, self-reported extent of recovery correlated well with performance on the Glasgow Outcome Scale (p <.001 at 6 and 12 mo) and Wechsler Adult Intelligence Scale Performance IQ (p =.001 at 12 mo). The major reported barrier to recovery was physical difficulties, which constituted over half of the concerns at all time periods. Report of physical-related concerns decreased significantly (p =.002) over time whereas cognition-related concerns increased significantly (p =.02). CONCLUSION: Brain injury survivors consider themselves to have greater recovery than previously reported by clinicians or family members, consider physical problems a significant factor in their recovery, and appear to become more aware of cognitive impairments over time.

Adolescent↗
PubMed2001

The distress and risk assessment method (DRAM).

Our aim was to judge the influence of preoperative psychological disturbance on the outcome of lumbar discectomy. We evaluated 66 patients, before and after operation, using a self-administered questionnaire. Disability was assessed using the Oswestry disability index and psychological disturbance the Distress and Risk Assessment Method (DRAM) score. Patients were classified as normal, at risk or distressed, and the outcome of surgery in the three groups was compared at a follow-up of six months. The mean self-reported preoperative disability was significantly higher in those with psychological disturbance. A total of 54 patients (82%) returned completed postoperative questionnaires. Postoperative disability scores at six months were not significantly different in the three risk groups. Psychological disturbance improved after surgery. Our study suggests that the early outcome of lumbar discectomy is not affected by preoperative psychological disturbance. We conclude that a patient with a symptomatic prolapsed intervertebral disc should not be denied surgery on the basis of preoperative psychological assessment.

Adult↗
PubMed2000

Enhanced peroxynitrite formation is associated with vascular aging.

Vascular aging is mainly characterized by endothelial dysfunction. We found decreased free nitric oxide (NO) levels in aged rat aortas, in conjunction with a sevenfold higher expression and activity of endothelial NO synthase (eNOS). This is shown to be a consequence of age-associated enhanced superoxide (.O(2)(-)) production with concomitant quenching of NO by the formation of peroxynitrite leading to nitrotyrosilation of mitochondrial manganese superoxide dismutase (MnSOD), a molecular footprint of increased peroxynitrite levels, which also increased with age. Thus, vascular aging appears to be initiated by augmented.O(2)(-) release, trapping of vasorelaxant NO, and subsequent peroxynitrite formation, followed by the nitration and inhibition of MnSOD. Increased eNOS expression and activity is a compensatory, but eventually futile, mechanism to counter regulate the loss of NO. The ultrastructural distribution of 3-nitrotyrosyl suggests that mitochondrial dysfunction plays a major role in the vascular aging process.

Acetylcholine↗
PubMed1999

Immunolocalization and expression of prohibitin, a mitochondrial associated protein within the rat ovaries.

This study was designed to determine the cellular distribution and pattern of expression for the mitochondria-associated protein, prohibitin, during the transitional stages of follicular differentiation within the rat ovary. Immunohistochemical staining techniques were used on frozen sections to examine the localization of prohibitin to preantral, antral, preovulatory, and atretic follicles. Prohibitin localization was also determined in corpus luteum from adult rats, in addition to those from infant and juvenile ovaries, before and after gonadotropin stimulation. Western and Northern blotting techniques were used for qualitative and quantitative assessment of prohibitin expression levels within the ovary. Prohibitin was localized within granulosa cells of infant and juvenile ovaries in a relatively heterogeneous staining pattern. The oocyte also exhibited robust prohibitin expression at all stages of follicular development. In addition, strong prohibitin expression was evident in the corpus luteum as well as in follicles undergoing atresia. Additional data derived from studies involving a GnRH-agonist indicate that increases in prohibitin protein expression correlate with the initial events of apoptosis. Collectively, these results support a growth regulatory role for prohibitin within the rat ovary. Therefore, we propose that prohibitin may serve as an important regulator of granulosa cell fate during follicular development.

Animals↗
PubMed1998

Cytochemical demonstration of sites of hydrogen peroxide generation and increased vascular permeability in isolated pig hearts after ischaemia and reperfusion.

Isolated pig hearts, subsequently perfused with pig or human blood, were prepared for the cytochemical demonstration of sites of hydrogen peroxide generation and increased vascular permeability. Oxidant stress was associated with ultrastructural changes commonly seen following myocardial reperfusion. In addition, the precipitation of cerium perhydroxide following perfusion with physiological saline containing cerium chloride suggested the vascular endothelium and leukocytes as sources of oxidants. This was associated with rapid penetration of horseradish peroxidase through the intercellular clefts of the vascular endothelium into the interstitial space, suggesting increased vascular leakiness at these sites. The rapid penetration of horseradish peroxidase was observed at all monitored periods of reperfusion with pig or human blood. This indicates that the increased permeability occurred during the ischaemic period and continued during reperfusion. Morphological damage was greatest in pig hearts reperfused with whole human blood and this was attenuated if the blood was preabsorbed to remove antibodies prior to reperfusion. We conclude that oxidant stress was initiated during ischaemia and continued during reperfusion in this model.

Animals↗
PubMed1995

Capillary surface area is reduced and tissue thickness from capillaries to myocytes is increased in the left ventricle of streptozotocin-diabetic rats.

The left ventricles of normal and diabetic rats, fixed by vascular perfusion were examined using modern stereological techniques to quantify changes in the morphology accompanying streptozotocin-induced diabetes. The heart weight to body weight ratio increased in diabetic rats whilst left ventricular volume remained unchanged. Papillary muscles from the diabetic animals showed prolonged time to peak tension and relaxation, and altered sensitivity to adrenalin and calcium. The apparent cardiomyopathy observed when body weight loss exceeds heart weight loss in experimental diabetes was accompanied by specific pathological changes in the composition of the left ventricle. In the diabetic animals the volume of extracellular components increased threefold and the volume of capillaries fell. The surface density and total surface area of capillaries was reduced, and oxygen diffusion distance to myocyte mitochondria increased. The volume fraction of myocyte mitochondria was reduced during streptozotocin-induced diabetes.

Animals↗
PubMed1991

Bony transfixion of the median nerve following Colles' fracture. A case report.

Reported herein is the case of a 45-year-old man with a Colles' fracture complicated by median nerve transfixion by a bony spike. This seems not to have been reported previously and reinforces the belief that early median nerve exploration should be performed if there is nerve dysfunction associated with a volar bony spike on the postreduction roentgenograms.

Colles' Fracture↗
PubMed1990

Factors influencing the result of posterior spinal fusion in the treatment of adolescent idiopathic scoliosis.

Sixty-six consecutive patients with adolescent idiopathic scoliosis treated by posterior spinal fusion using Harrington distraction compression instrumentation were followed for a minimum of 3 years. Initial surgical correction was satisfactory, but during the follow-up period, mean 4.4 years (3-5 years), there was a loss of correction. Several factors (age, sex, the number of vertebrae in the fusions, and the use of cross wires) were important influences on correction. A method of assessing the balance of a posterior spinal fusion is described that is useful when assessing radiographs.

Adolescent↗
PubMed1988

Intra-articular knee injuries in racquet sports. A review of 128 arthroscopies.

Within the last decade, there has been a significant increase in racquet sport participation. The authors report that in a 5-year period, 17% of the injuries seen in a busy sports injuries clinic were associated with racquet sports, and over half of these were injuries to the knee. The findings are reported of those patients requiring knee arthroscopy, and the patterns of injury sustained are identified. Injuries to the knee in racquet sports are largely unavoidable and are inherent to the nature of the game.

Adult↗
PubMed1988

Metastatic carcinoid of bone. Report of two cases and review of the literature.

The skeletal manifestations of malignant carcinoid seem not to have been reported in the orthopedic literature. Bronchial and hindgut carcinoid tumors are less numerous than midgut tumors but metastasize to bone much more frequently. Carcinoid skeletal deposits are usually osteoblastic and most commonly affect the axial skeleton. The radiologic appearance is frequently indistinguishable from prostatic skeletal metastases or chronic sclerosing osteomyelitis. Two cases of skeletal metastases from midgut carcinoid are reported to demonstrate that metastases from carcinoid should be considered in the differential diagnosis of either bone malignancy or chronic sclerosing osteomyelitis.

Aged↗
PubMed1988

New clinical test for fracture of the scaphoid.

The authors noted that in patients with scaphoid fractures pronation of the affected wrist followed by ulnar deviation produces pain in the anatomic snuff box that is not present in those without a scaphoid fracture. They therefore evaluated this test prospectively in 73 patients. The test gave a 52% positive predictive value and a 100% negative predictive value. They recommend that the test may be used with confidence in the emergency department to exclude a scaphoid fracture in patients with clinical features suggesting scaphoid injury but a normal x-ray film. Use of this test would reduce the number of patients whose wrists are needlessly immobilized in a scaphoid cast.

Carpal Bones↗
PubMed1987

Recurrent ureteric obstruction in association with Henoch-Schönlein purpura.

The most common urological manifestation of Henoch-Schönlein purpura is focal proliferative glomerulonephritis. Ureteric obstruction as a consequence of the disease has been reported in children but is rare. We report an adult male patient with Henoch-Schönlein purpura causing unilateral, bi-focal, recurrent ureteric obstruction. We speculate that ureteric involvement in Henoch-Schönlein purpura may be more common than hitherto suspected and that even with a demonstrable obstructive episode, consideration must be given for an initial conservative approach.

Adult↗
PubMed1986

Decreased circumcision rate with videotaped counseling.

Despite the lack of medical indication for routine circumcision in the newborn, neonatal circumcision continues to be done on the vast majority of male infants in the United States. A trial of videotaped "informed consent" counseling was undertaken to determine whether such counseling could affect the parental choice about circumcision. We studied the circumcision frequency rate (CFR) after videotape counseling. We compared it to the rates following standard oral counseling. Videotaped counseling, in contrast to the standard physician-parent oral counseling, significantly reduced the incidence of parents' requests for routine neonatal circumcision.

Circumcision, Male↗
PubMed1985

Bacterial and viral pathogens causing fever in infants less than 3 months old.

We studied 182 sick, febrile (temperature greater than 38 degrees C) infants less than 3 months of age, who presented at our Tripler Army Medical Center, Honolulu, during a one-year period, to determine the relative causes of fever in this age group. Blood, cerebrospinal fluid, urine, nasopharyngeal secretions, and stool specimens were cultured for bacterial and viral pathogens. Paired acute and convalescent sera were collected to serologically confirm infection in infants from whom viral isolations were obtained only from the nasopharynx or stool. A viral pathogen was isolated in 75 infants (41%) and a bacterial pathogen was isolated in 27 infants (15%). Nonpolio enteroviruses were the most common pathogens demonstrated. They were isolated from 64 infants (35%), and 40 (62%) of these infants had aseptic meningitis, the most frequently made diagnosis. Urinary tract infection was the most common bacterial infection observed. It occurred in 20 infants (11%) and was most often seen without associated pyuria in uncircumcised male infants. Salmonellosis, the second most common bacterial infection, was observed in six infants (3%), and two of these did not have diarrhea or other gastrointestinal tract symptoms. No infant had septicemia and only one infant had bacterial (group B streptococcal) meningitis.

Bacterial Infections↗
PubMed1984

Schizophrenic patients and their families. A survey in a psychiatric service based on a DGH unit.

We identified the population of schizophrenic patients under 65 in a geographically defined area. The number using psychiatric services based on a new District General Hospital unit in the course of one year was 364, a prevalence of 2.2 per 1000 adult population. Half the patients lived in supportive private households, most often with spouses or mothers. More women than men married and retained supporters. Patients and their primary supporters were interviewed separately. The PSE Catego programme classed 47 per cent of patients as psychotic. Supporters reported disturbed behavior in 65 per cent of patients, and restricted social performance in 78 per cent. There was evidence of hardship (emotional and physical ill-health, problems with children) in 90 per cent of households. Supporters' subjective distress was directly related to the presence of psychosis and disturbed behaviour and inversely related to the duration of the illness. Drop-out and failure to take medication appeared to be causes of the relatively high prevalence of psychosis.

Adolescent↗
PubMed1983

Septic arthritis caused by Kingella kingae.

Kingella kingae is a slow-growing, fastidious gram-negative coccobacillus that is a normal inhabitant of the oropharynx of man, but it has rarely been implicated as a human pathogen. Two cases of septic arthritis caused by this organism are reported along with a review of seven previously reported cases of infections caused by this organism. Bone and joint infections predominate. Gram's-stained smears of pus from bone or joint fluid aspirate have been negative for organisms, and a delay of growth in cultures with initial difficulty in classification of the isolate is characteristic. Kingella kingae organisms have been uniformly sensitive to the penicillins and all other commonly used antibiotics that were tested. Response to treatment was good in all nine patients found to have infections caused by this organism.

Anti-Bacterial Agents↗