Search PubMed⌕ Search

Biomedical subjects

J G Wright

Publications and source records attributed to J G Wright.

At least 127 records · Page 7Linked to original sources
PubMed1994

Reliability and validity of the grading of heterotopic ossification.

The purpose of this study is to assess the reliability and validity of the Brooker grading of heterotopic ossification. Anteroposterior hip radiographs of 77 patients, taken 6 months following total hip arthroplasty, were blindly evaluated twice by two surgeons using the Brooker scale. Patients were also evaluated with the Harris hip scale, and range of motion of the hip was determined. All inconsistencies in heterotopic ossification grading were reviewed by the same two surgeons who developed six points of clarification to minimize ambiguities in the Brooker grading criteria. A second set of 76 radiographs were reviewed by the two surgeons using this modified Brooker index. The intraobserver reliability of the two readers was good, with agreements of 77 and 86% and weighted kappa values of 0.63 and 0.69, respectively. The two surgeons demonstrated fair interobserver reliability on the first reading (agreement of 68% and weighted kappa of 0.57) that improved to a good level of reliability (agreement of 77% and weighted kappa of 0.68) using the revised Brooker index. The grade of heterotopic ossification was correlated (r = -.25, P = .005) with the aggregate range of hip motion, but had no relationship to the patient's Harris rating. In conclusion, the grading of heterotopic ossification is reliable. Although the severity of heterotopic ossification did not correlate with the Harris scale, the relationship between heterotopic ossification and range of motion indicates that the Brooker index is also a valid measurement.

Hip Joint↗
PubMed1994

Detection of phencyclidine in urine using a polarization fluoroimmunoassay.

A polarization fluoroimmunoassay was developed for the detection of phencyclidine in urine and the reagents were adapted for use on the Abbott TDx analyser. The assay was used to look for evidence of phencyclidine abuse, over a 6 month period, amongst patients attending drug abuse clinics in the East End of London. Although over 2000 patients' samples tested negative, the assay successfully detected phencyclidine in an external quality control scheme.

Animals↗
PubMed1994

Echocardiographic screening in neonates undergoing surgery for selected gastrointestinal malformations.

To compare echocardiography with clinical examination, radiography, and electrocardiography for the detection of congenital heart defects (CHD) a four year prospective study was carried out in 166 neonates with selected congenital gastrointestinal malformations (anorectal anomaly, tracheo-oesophageal fistula, duodenal atresia, exomphalos, and gastroschisis). Routine examination and investigation detected CHD in 16 neonates. Using echocardiography CHD was diagnosed in 38 (23%) neonates of whom five had two gastrointestinal malformations: in 22/57 (39%) with a tracheo-oesophageal fistula, 10/67 (15%) with an anorectal anomaly, 4/20 (20%) with exomphalos, 6/20 (30%) with duodenal atresia, and 1/7 with gastroschisis. A significantly higher incidence of CHD in neonates with gastrointestinal malformations was diagnosed using echocardiography (23%) compared with routine examination and investigation (9%). Early diagnosis of CHD allowed a unified approach to be presented to the family.

Abnormalities, Multiple↗
PubMed1994

Ontario patients' acceptance of waiting times for knee replacements.

OBJECTIVE: To determine waiting times for an initial orthopedic consultation and subsequent knee replacement surgery in Ontario and patients' acceptance of these waiting times. METHODS: Mailed patient survey to 185 randomly selected knee replacement recipients discharged from 5 Ontario hospitals between 1985 and 1990, with telephone followup after 2 mailings, implemented between May and July, 1992. Patients were asked about waiting times for their initial orthopedic consultation and subsequent knee replacement surgery and their acceptance of these waiting times. RESULTS: Of the 185 patients, 40 were excluded because they were deceased, unable to respond, or not traceable. Of the 145 eligible patients, 127 or 87.6% responded. The median waiting times for an initial consultation and for knee replacement surgery were 4.0 and 9.5 weeks, respectively. Waiting times did not change significantly over the 5-year study period (Pearson correlation coefficients: 0.07, p = 0.53, for consultation, and -0.08, p = 0.44, for surgery). The waiting times for consultation and surgery were acceptable to 93.2% (95% confidence interval: 88.7-97.7%) and 88.1% (95% confidence interval: 82.3-93.9%) of respondents, respectively. The average acceptable surgical waiting time of 13.2 weeks was significantly shorter than the not acceptable average of 34.3 weeks (p < 0.001). CONCLUSION: The average waiting periods for an initial orthopedic consultation and subsequent knee replacement surgery were relatively short, and the majority of patients considered their waiting times acceptable.

Data Collection↗
PubMed1994

Ask patients what they want. Evaluation of individual complaints before total hip replacement.

We aimed to assess individual differences in complaints in patients just before total hip replacement (THR) and the importance attached to the relief of each of them. In a pilot study, using open-ended interviews, we identified 16 main complaints, four of which (night pain, unequal leg length and discomfort during sexual and recreational activities) were not included in any of the six hip-rating scales in general use. Each of the 16 complaints was then assessed in 72 patients and rated for severity and the relative importance of relief. From this we calculated a severity-importance rating for each complaint and a patient-specific score for all complaints. The 72 patients had a mean age of 64 years (17 to 92) and 51% were men. The most important reasons for wanting a THR were day pain and walking difficulty, but the complaints mentioned above and not included in standard hip scores were also important. Greater attention to the individual requirements of patients might improve evaluation of the outcome of orthopaedic treatments.

Activities of Daily Living↗
PubMed1993

The expression of monocyte chemotactic protein (MCP-1) in human vascular endothelium in vitro and in vivo.

A monocyte chemotactic protein (MCP-1) is thought to play a major role in recruiting monocytes to the vascular endothelium where the adherence of monocytes is one of the earliest events in atherogenesis. We cloned MCP-1 cDNA from a lambda gt 11 cDNA library constructed from human aortic endothelial mRNA to test whether MCP-1 expressed in arterial endothelium is identical to those from other sources. A approximately 670 bp MCP-1 cDNA clone was identified and showed the identical sequence with the ones from other cell lines. Northern blot analysis using this cloned MCP-1 cDNA as probe revealed two hybridizing bands of RNA at 0.68 and 0.77 kb in human aortic, human pulmonary arterial, and human umbilical vein endothelial cell cultures. Primer extension analysis showed that the difference in size (approximately 90 bp) between the two transcripts is not due to a difference at the 5'-noncoding region. The amount of MCP-1 transcripts increased dramatically in aortic endothelial cells when stimulated with recombinant IL-1 alpha (100 units/ml), IL-1 beta (100 units/ml), or TNF-alpha (200 ng/ml). Northern blot and slot blot analysis of RNA isolated from both the endothelium and the underlying vessel wall of freshly removed human arteries and veins showed MCP-1 transcripts. This observation demonstrates for the first time that MCP-1 is expressed not only in atherosclerotic human arteries but also in symptom free arteries and veins in vivo.

Amino Acid Sequence↗
PubMed1993

Construction and characterization of a mercury-independent MerR activator (MerRAC): transcriptional activation in the absence of Hg(II) is accompanied by DNA distortion.

The MeR regulatory protein of transposon Tn501 controls the expression of the mercury resistance (mer) genes in response to the concentration of mercuric ions. MerR is unique among prokaryotic regulatory proteins so far described in that it acts as a repressor [-Hg(II)] and an activator [+Hg(II)] of transcription of the mer genes, but binds to a single site on the DNA in both cases. This transcriptional activation process has been postulated to involve a protein-induced conformational change in the DNA that allows RNA polymerase more readily to form an open complex at the promoter. It has been shown [Frantz and O'Halloran (1990) Biochemistry, 29, 4747-4751] that activation of transcription by MerR in the presence of mercury is accompanied by hypersensitivity of the operator to chemical nucleases that are sensitive to local distortion in DNA structure. Here we describe specific mutations in MerR that allow the protein to stimulate transcription in the absence of the allosteric activator Hg(II). We demonstrate that the degree of activation caused by these mutants directly correlates with the degree of DNA distortion as measured by the hypersensitivity of MerR-DNA complexes to the nuclease Cu-5-phenyl-o-phenanthroline. These results support the model described above.

Allosteric Regulation↗
PubMed1993

Prospective evaluation of magnetic resonance imaging in the management of acute diabetic foot infections.

Infectious complications of the foot are a major cause of morbidity and mortality in diabetic patients. This prospective study evaluated the ability of MRI to adequately direct the medical and surgical management of 41 diabetic patients with acute foot infections. Forty-seven MRI scans of the foot in question were performed and classified as consistent with osteomyelitis, abscess, cellulitis or diffuse soft tissue infection, or any combination of these. Twenty-seven scans were negative or showed ill-defined soft tissue infection, or superficial cellulitis. Nineteen of these infections were treated nonoperatively and 17 resolved without surgical intervention. MRI was unsuccessful in directing management in one patient in whom an abscess spontaneously drained but was not seen on an MRI scan 4 days earlier. Eight scans revealed focal osteomyelitis and all eight of these patients were successfully managed with one operation. MRI showed a focal abscess in 12 patients, and adequate drainage was achieved without excessive disruption of uninvolved tissue planes in 11 of these patients. The remaining patient required a major amputation from the outset. Based on clinical outcome during the acute hospitalization period, operative findings, and/or pathologic confirmation, the positive predictive value of MRI in defining infectious pathology in the foot was 100% in this series of 20 positive scans. The negative predictive value of MRI was 96%. On the basis of this experience, we conclude that MRI is a diagnostic modality particularly well suited to evaluate acute diabetic foot infections and reliably aids in the management of acute infection to avoid exploration and debridement of uninvolved tissue.(ABSTRACT TRUNCATED AT 250 WORDS)

Abscess↗
PubMed1993

Magnetic resonance angiography in the preoperative evaluation of abdominal aortic aneurysms.

Magnetic resonance angiography (MRA) and magnetic resonance imaging (MRI) are noninvasive techniques of visualizing blood vessels without the use of intravenous contrast or ionizing radiation. This prospective study assessed preoperative MRA and MRI in the evaluation of 28 patients with abdominal aortic aneurysm (AAA). MRI and MRA accurately predicted the extent of cephalad AAA, the patency of the superior mesenteric artery, and the course of the left renal vein, but were less accurate in defining the extent of caudal AAA, flow of the inferior mesenteric artery, and multiple renal arteries. This study suggests that MRI and MRA are alternatives to the combination of angiography and computed tomographic scan in the preoperative evaluation of patients with suspected AAA and no evidence of mesenteric or renal ischemia. When combined with preoperative segmental Doppler arterial studies, an accurate surgical plan may be formulated. Further refinements in image acquisition and postprocessing software analysis will advance the use of MRI and MRA for complete evaluation prior to elective AAA repair.

Aged↗
PubMed1993

Effects of age and aerobic capacity on arterial stiffness in healthy adults.

BACKGROUND: It has been well established that arterial stiffness, manifest as an increase in arterial pulse wave velocity or late systolic amplification of the carotid artery pressure pulse, increases with age. However, the populations studied in prior investigations were not rigorously screened to exclude clinical hypertension, occult coronary disease, or diabetes. Furthermore, it is unknown whether exercise capacity or chronic physical endurance training affects the age-associated increase in arterial stiffness. METHODS AND RESULTS: Carotid arterial pressure pulse augmentation index (AGI), using applanation tonometry, and aortic pulse wave velocity (APWV) were measured in 146 male and female volunteers 21 to 96 years old from the Baltimore Longitudinal Study of Aging, who were rigorously screened to exclude clinical and occult cardiovascular disease. Aerobic capacity was determined in all individuals by measurement of maximal oxygen consumption (VO2max) during treadmill exercise. In this healthy, largely sedentary cohort, the arterial stiffness indexes AGI and APWV increased approximately fivefold and twofold, respectively, across the age span in both men and women, despite only a 14% increase in systolic blood pressure (SBP). These age-associated increases in AGI and APWV were of a similar magnitude to those in prior studies of less rigorously screened populations. Both AGI and APWV varied inversely with VO2max, and this relationship, at least for AGI, was independent of age. In endurance trained male athletes, 54 to 75 years old (VO2max = 44 +/- 3 mL.kg-1.min-1), the arterial stiffness indexes were significantly reduced relative to their sedentary age peers (AGI, 36% lower; APWV, 26% lower) despite similar blood pressures. CONCLUSIONS: Even in normotensive, rigorously screened volunteers in whom SBP increased an average of only 14% between ages 20 and 90 years, major age-associated increases of arterial stiffness occur. Higher physical conditioning status, indexed by VO2max, was associated with reduced arterial stiffness, both within this predominantly sedentary population and in endurance trained older men relative to their less active age peers. These findings suggest that interventions to improve aerobic capacity may mitigate the stiffening of the arterial tree that accompanies normative aging.

Aging↗
PubMed1993

Exposure rates to patients' blood for surgical personnel.

BACKGROUND: Surgical personnel are at risk of contracting blood-borne diseases through exposure to patients' blood. Exposure rates for each surgical subspecialty have not been previously reported. The purpose of this study was to determine the rates of exposure to patients' blood for operating room personnel. METHODS: The study was conducted at Yale-New Haven Hospital, a level I trauma center and tertiary care hospital. During a 3-month period, exposed personnel were interviewed by a study nurse immediately after a cutaneous exposure to blood or after a sharp injury. RESULTS: During 2292 surgical procedures, 70 sharp injuries and 168 cutaneous exposures to blood were reported. The combined exposure rate (skin contact and sharp injury) was 10.4 per 100 procedures (95% confidence interval, 9.1 to 11.6) and ranged from 21.2 for general surgery to 3.3 for pediatric surgery (goodness-of-fit chi-squared, p < 0.001). The combined exposure rates were also significantly different among types of surgery and ranged from 18 for laparotomies to 4.3 for craniotomies (chi-squared, p < 0.001). The overall sharp injury rate was 3.1 per 100 procedures (95% confidence interval, 2.3 to 3.8) and ranged from 4.3 for general surgery to 1.3 for vascular surgery. CONCLUSIONS: The rate of exposure to blood for operating room personnel, which differ from prior studies, was 10.4 per 100 procedures and was highest for general surgical procedures. The differences in rates among studies might be attributable to different surgical technique, dissimilar case-mix, or different research methods relating to definition or ascertainment of exposure.

Blood↗
PubMed1993

Human immunodeficiency virus transmission between surgeons and patients in orthopaedic surgery.

Surgeons are at risk for contracting human immunodeficiency virus (HIV) from patients. The risk of HIV transmission between patient and surgeon and the potential strategies to reduce the risk of HIV transmission are important. Continuous occupational exposure makes the risk of HIV transmission greater for surgeons than patients. Although the risk of seroconversion after a single exposure is relatively low, the risk for surgeons is more appropriately expressed as a cumulative lifetime risk. The estimated cumulative risk of HIV seroconversion for surgeons may be as high as 1 to 4%. Currently available strategies to prevent HIV transmission require knowledge of the mechanisms of exposure. Adequate barriers, such as double-gloving, waterproof outerwear, and face protection, should be worn for most, if not all, orthopaedic procedures. Additional specific strategies, however, are required to minimize sharp injuries. Surgeons should report any significant exposure to the occupational health department of their institution. Hospitals should have appropriate guidelines and procedures for counseling exposed surgeons, HIV testing of source patients, consideration of zidovudine prophylaxis, and disability insurance policies for surgeons who are occupationally infected with HIV.

Gloves, Surgical↗