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K Chambers

Publications and source records attributed to K Chambers.

18 recordsLinked to original sources
PubMed1999

Validity of the visual function index (VF-14) in patients with retinal disease.

OBJECTIVE: To test the validity of the Visual Function Index (VF-14) in patients with retinal disease. DESIGN: A self-administered questionnaire package in association with clinical examination findings. PARTICIPANTS: Consecutive patients attending the Vancouver General Hospital Eye Care Centre, Vancouver, British Columbia, retina clinic between May 1 and August 15, 1998. MAIN OUTCOME MEASURES: Responses to the questionnaire package as they relate to global self-assessment scales and visual acuity. In addition, correlations were calculated between the VF-14, the 36-Item Short-Form Health Survey, a Weighted Comorbidity Scale, and visual acuity scores. RESULT: Five hundred forty-seven patients were given the questionnaire package to complete. The VF-14 demonstrated a moderately strong positive association with patient self-rating of amount of trouble, satisfaction, and overall quality of vision. Correlations between the 36-Item Short-Form Health Survey, visual acuity, and the global scales were mild to moderate. The VF-14 was moderately correlated with visual acuity in the better and the worse eyes. CONCLUSIONS: This study provides support for the validity of the VF-14 as a measure of functional impairment in patients with retinal disease. Once responsiveness has been measured and an analysis of disease subtypes has been carried out, the VF-14 will be ready for inclusion in clinical trials to evaluate patients' functional ability. Further implementation and development of this outcome measure will better our understanding of the utility of the functional assessment format for patients with retinal disease.

Adolescent↗
PubMed1999

Action leadership: the development of an approach to leadership enhancement for grassroots community leaders in children's mental health.

The last decade has seen the development of a number of interagency systems for children with serious emotional disturbances and their families. Many public sector agencies, however, continue to have inadequate or fragmented services. It is believed that effective systems of care for children and families will not be adequate until more parents and community residents are involved in all phases of systems development. Consequently, the need for the development of leadership models that enhance the involvement of grassroots community leaders is crucial. This article summarizes a research team's preliminary experience in developing an "action leadership" model that empowers grassroots community leaders toward action. The team discovered that leadership enhancement and development of grassroots community leaders is not a static skill attribute of an individual but rather is acquired through a dynamic process in which both the facilitator of a community leadership initiative and its natural leaders are active participants in a shared learning and change experience.

Child↗
PubMed1999

Sex differences in male-typical copulatory behaviors in response to androgen and estrogen treatment in rats.

The present experiment was performed to test the hypothesis that gender differences in the capacity for brain estrogen synthesis could constitute a sexually dimorphic mechanism that limits the activational effects of testosterone (T) in females, and enhances them in males. We determined the effects of treatments with equivalent levels of either T or estradiol (E2) on olfactory behavior and mounting in age-matched heterosexually naive gonadectomized male and female rats that were genitally ansthetized with lidocaine paste in order to minimize the contribution of sexually dimorphic somatosensory inputs to the expression of copulatory behavior. We found that T stimulated mounting to a greater extent in males than in females, but had equivalent effects on mount latency and genital investigation in the two sexes. On the other hand, E2 stimulated equivalent levels of mounting in males and females and reduced mount latency to a similar extent in males and females. However, E2 had a pronounced effect on the levels of genital investigation in males but not in females. Serum steroid levels and the levels of nuclear steroid receptor occupation in the brain were not different between males and females, suggesting that the behavioral differences between males and females cannot be attributed to differences in peripheral steroid metabolism or brain uptake. The results obtained corroborate previous studies suggesting that female rats normally undergo considerable male-typical behavioral masculinization during fetal development. However, such male-typical features of normal development in female rats do not extend to the regulation of preoptic aromatase activity or to the capacity of females to display olfactory behaviors in response to adult E2 exposure, functions which are sexually dimorphic even in the rat. The present results support the view that gender differences in the capacity for brain estrogen synthesis contribute to the sexually dimorphic display of T-stimulated male-typical sexual motivation and copulatory behavior in rats.

Animals↗
PubMed1998

Clinical utility of a portable ultrasound device in intermittent catheterization.

OBJECTIVE: To evaluate the clinical utility of a new portable ultrasound device (PUD) in the management of intermittent catheter programs in patients with neuropathic bladder. DESIGN: Intervention study using randomized control trial. SETTING: Tertiary care center providing inpatient and ambulatory rehabilitation services to persons with neurologic disabilities. PARTICIPANTS: Thirty-eight inpatients and outpatients with neuropathic bladders requiring intermittent catheterization. MAIN OUTCOME MEASURES: Mean frequency of intermittent catheterization, mean number of episodes of overdistension, and patient satisfaction as measured with a Patient Satisfaction Questionnaire. RESULTS: The mean frequency of catheterization per day was reduced in the PUD group in comparison with controls (2.99 vs 4.12, p = .026). The number of episodes of overdistension was also reduced in the PUD group but did not reach statistical significance (12.45 vs 14.76, p = .61). Subjects generally expressed satisfaction with the PUD, with 16 of 18 patients at least somewhat satisfied with the device. CONCLUSION: The PUD is a useful tool for clinicians in patients undergoing intermittent catheterization programs that can reduce the number of required catheters. It is associated with a high degree of patient satisfaction.

Adult↗
PubMed1997

A primatized MAb to human CD4 causes receptor modulation, without marked reduction in CD4+ T cells in chimpanzees: in vitro and in vivo characterization of a MAb (IDEC-CE9.1) to human CD4.

A Primatized anti-CD4 monoclonal antibody (MAb), CE9.1, with V-domain from cynomolgus macaque (showing 92% homology with human consensus sequence V-domains), and a human IgG1 constant region, was characterized in vitro and in vivo in chimpanzees. This MAb binds human CD4 with Kd of 1.0 nM and was also able to bind to human IgG Fc receptors (Fc gamma R). However, despite being of the IgG1 subclass, CE9.1 did not bind to complement component C1q, nor did it mediate complement-dependent cytotoxicity. Examination of T cells from a number of species showed restricted reactivity for CE9.1, recognizing only human and chimpanzee CD4. In both human and chimpanzee MLRs, it had an IC50 of about 10.0 ng/mL. Therefore, a chimpanzee in vivo model was used to characterize CE9.1, CE9.1 caused transient decrease in the number of lymphocytes bearing the CD4 receptor starting at doses of 0.3 mg/kg in an in vivo dose ranging study in one chimpanzee. This effect was reversed within approximately 7 days. In a multiple high-dose study in which 10.0 mg/kg of CE9.1 was administered at intervals of 1-3 months, there was a dramatic loss of CD4 marker with a reciprocal increase in the number of CD3+ CD8- CD4- cells. The CD4 receptor was totally undetectable on these lymphocytes for 1-2 weeks, with a gradual, but complete, reversal within 4 weeks. We interpret these observations as receptor modulation because, although there was apparent loss of CD4+ lymphocytes, an equivalent number of CD3+CD8- T lymphocytes were present in circulation in all four chimpanzees treated with 10.0 mg/kg CE9.1. Even at this high dose, only limited reduction of CD4+ T lymphocytes was observed in these animals. These observations are in sharp contrast to what has been reported in rodents or in human clinical studies using other IgG1 mAbs to human CD4. CD8 counts, although variable, remained unaffected by CE9.1 treatment. No adverse events were observed following administration of CE9.1 to chimpanzees, and there was no detectable host immune responses to the Primatized MAb.

Animals↗
PubMed1995

The Christensen prosthesis. A retrospective clinical study.

The objective of this study was to determine if the Christensen temporomandibular joint prosthesis system in an effective alternative in treating patients with severe temporomandibular joint disorders. A total of 69 patients who were not responsive to either nonsurgical or prior surgical treatments were placed into one of three treatment groups depending on the following diagnoses: (1) placement of a glenoid fossa-eminence prosthesis with meniscus retention (22 patients, 40 joints); (2) placement of a glenoid fossa-eminence prosthesis without retention of the meniscus (26 patients, 49 joints); (3) total joint replacement (21 patients, 34 joints). Patients were evaluated immediately before surgery and at regular intervals after surgery for an average of 3.1 years. Success was measured as a significant improvement of function and decrease in pain as measured on a visual analogue scale, as well as improved incisor opening as measured with a Therabite Scale (Lorenz Surgical, Jacksonville, Fla.). Comparison of mean and average pre- and postsurgical values for all groups and criteria showed significant improvement. Results of this study indicate that the Christensen temporomandibular joint prosthesis system may offer a viable method for the treatment of severe temporomandibular joint disease with a high degree of success.

Adult↗
PubMed1995

Use of pedicled fat pad graft as an adjunct in the reconstruction of palatal cleft defects.

The purpose of this article is to provide the rationale for the use of pedicled buccal fat pad grafts as an adjunct to the reconstruction of palatal or dentoalveolar clefts in cases when healing by secondary intention may need to be considered and integrated into the initial treatment plan because of the size of the defect or qualitative or quantitative tissue constraints. Four representative cases are presented in which a pedicled buccal fat graft was adjunctively used in conjunction with pedicled mucosal flaps to gain closure of large oroantral or oronasal cleft deformity.

Adipose Tissue↗
PubMed1995

The correlation of multichannel urodynamic pressure-flow studies and American Urological Association symptom index in the evaluation of benign prostatic hyperplasia.

PURPOSE: We correlated multichannel pressure-flow urodynamics and the American Urological Association (AUA) symptom index in the evaluation of benign prostatic hyperplasia. MATERIALS AND METHODS: We evaluated 121 consecutive, symptomatic patients older than 55 years with the AUA symptom score and multichannel pressure-flow urodynamic studies. Testing was performed during a single session and the data obtained from 103 patients were plotted on the Schäfer nomogram for assessment of outflow obstruction. Linear regression statistical analysis was used to determine correlations. RESULTS: There was no significant correlation between uroflowmetry and Schäfer curves (r = 0.173 to 0.326), uroflowmetry and AUA symptom scores (r = 0.134 to 0.153) and, most importantly, AUA symptom scores and Schäfer curves (r = 0.025 to 0.137). CONCLUSIONS: We conclude that these modalities measure independent variables, and should not be linked in the evaluation and treatment decision of the patient with prostatism.

Aged↗
PubMed1993

Use of a low pressure liquid chromatography system for haemoglobinopathy screening.

A closed low pressure liquid chromatography system (LPLC) is described which is suitable for haemoglobinopathy screening. The system (Glycomat) was originally developed for the quantitation of the glycated haemoglobin (HbA1). The same biochemical principles have been applied to the separation of haemoglobin A2 (HbA2) and haemoglobin variants. The instrument offers three modes of use including a fast haemoglobin elution, a variant screen and a HbA2 assay for thalassaemia screening. The fast screen isolates all of the common haemoglobin variants except HbE which elutes with HbA. This mode is a more rapid alternative to the Sickledex test. The variant screen produces a wider separation of abnormal variants giving an identification and quantitation for each. The HbA2 assay separates this minor fraction from all other haemoglobins giving an accurate percentage. Abnormal variants are also separated. To validate the HbA2 assay 252 samples were assayed by the cellulose acetate electrophoresis/elution method and LPLC with a correlation of 0.932. The system provides an accurate and sensitive alternative to traditional manual chromatography and electrophoresis methods. The automated sampler allows batches from 1-99 samples to be processed with significant savings in operator time.

Chromatography, Liquid↗
PubMed1992

Effect of recombinant human erythropoietin on erythropoiesis in homozygous sickle-cell anaemia and renal failure.

The development of end-stage renal disease (ESRD) in patients with sickle-cell anaemia results in increased transfusion dependence, increasing the risk of iron overload. Correction of anaemia with recombinant human erythropoietin (rHuEpo) in dialysis patients might also result in stimulation of haemoglobin F production, which protects against sickling, although very high doses were required to achieve this effect in non-uraemic animals. rHuEpo was administered to three transfusion-dependent patients with ESRD and homozygous sickle-cell disease (initial dose 100 U/kg twice weekly, increasing to 125 U/kg at 6 weeks, and to 150 U/kg at 9 weeks in two patients). This resulted in reticulocytosis and increased circulating erythroid blast-forming units. Total haemoglobin was predominantly HbA (i.e. transfused blood) at the start of the study, reflecting transfusion dependence, but after 3 months' treatment was between 60 and 94% HbS. No sickling crises occurred. Haemoglobin F remained at less than 3% of total haemoglobin. One patient was withdrawn at 10 weeks with CAPD peritonitis. The other two patients completed 12 weeks' treatment without transfusion but final Hb concentrations were 4.5 and 5.5 g/dl. Whether larger doses of rHuEpo will be more successful in managing such patients remains unclear. No effect on HbF production can be expected.

Adult↗
PubMed1991

Automated quantitative microcolumn chromatography of haemoglobin A2.

Automated cation exchange microcolumn chromatography of haemoglobins has been modified for the analysis of haemoglobin A2. It provides the quantitative data of sufficient precision and specificity for the investigation of potential heterozygotes for beta-thalassaemia. Results have been compared with an established method of electrophoresis followed by densitometry of the eluted bands.

Chromatography, Ion Exchange↗
PubMed1986

Preservation of neuronal function during prolonged focal cerebral ischemia by ventriculocisternal perfusion with oxygenated fluorocarbon emulsion.

The left middle cerebral artery and both carotid arteries of 17 cats were occluded to evaluate the effects of oxygenated fluorocarbon emulsion on brain ischemia. Carotid and middle cerebral arteries were occluded concurrently for 2 hours, followed by occlusion of the middle cerebral artery only for another 24 hours. Six animals were treated with oxygenated fluorocarbon emulsion delivered by ventriculocisternal perfusion, 5 received ventriculocisternal perfusion with mock cerebrospinal fluid, and 6 were untreated. Perfusions were started 3 hours after the initial ischemic insult. Infarct size judged by tetrazolium staining and standard neuropathological stains was significantly smaller in the treated animals. The mechanism of protection is as yet unknown, but most likely reflects oxygen/nutrient diffusion into the ischemic middle cerebral artery zone from the ventricular fluorocarbon, or removal of harmful metabolites. The results imply that ventriculocisternal perfusion with fluorocarbon emulsion can preserve neuronal function during a major cerebral vessel occlusion. In the cat, therapy is effective if begun within 3 hours after ischemia starts.

Animals↗
PubMed1984

Pain amelioration after thoracotomy: a prospective, randomized study.

Twenty patients undergoing a posterolateral thoracotomy for lung resection or a nonpulmonary procedure were divided into four groups. Group 1 was the control group. Patients in Group 2 had an intercostal nerve block at the time of closure. Those in Group 3 underwent a continuous intercostal nerve block for five days. Electronic pain control was used in Group 4. An additional group of patients underwent operation through an anterolateral thoracotomy (Group 5) and was compared with the control group. Breathing performance was evaluated daily for five days with bedside spirometry, and intergroup comparison was done utilizing the unpaired t test and analysis of variance. Forced expiratory volume in one second, expressed as percent of preoperative values, was significantly better in Group 3 (continuous intercostal nerve block) at 52.4 +/- 9.2% (standard deviation; p less than 0.05) and in Group 5 (anterolateral thoracotomy) at 52.0 +/- 7.5% (p less than 0.05) than in the control group (38.4 +/- 8.8%) five days postoperatively. It is concluded that bedside spirometry is a simple and reliable technique to assess postoperative changes in ventilatory mechanics due to pain. The pain that follows posterolateral thoracotomy can be substantially decreased with a continuous intercostal nerve block. Anterolateral thoracotomy is notably less painful than posterolateral thoracotomy and should be considered the approach of choice for patients with decreased pulmonary reserve who undergo uncomplicated pulmonary resection.

Adult↗
PubMedDate not supplied

Prenatal spinal evaluation and functional outcome of patients born with myelomeningocele: information for improved prenatal counselling and outcome prediction.

OBJECTIVE: Prenatal ultrasonography can localize the level of the spinal cord malformation, allowing prediction of the potential postnatal neurological deficit and functional prognosis. METHODS: This study has two evaluations: (a) a retrospective prenatal review of 26 fetuses with spinal dysraphism (1987-1991), and (b) a follow-up descriptive study of patients (1971-1981) who underwent closure of the spinal lesion and ventricular shunting in the neonatal period. RESULTS: Prenatal ultrasound evaluation enabled the accurate definition of the last intact vertebral level which allows separation of fetuses into three functional groups (last intact level L2, L3-4, L5-sacral). Patterns of ambulation, urinary and bowel continence, and school performance vary according to level of spinal lesion and the neurological deficit. The need for ventricular shunts, the incidence of other spinal malformations and surgical interventions did not vary with the level of the spinal lesion. CONCLUSIONS: The functional outcome for patients with myelomeningocele is variable; however, distinct patterns emerge based on the level of spinal dysraphism and the resultant neurological deficit. By relating the level of the fetal spinal lesion to outcome data, more precise functional prognoses can be given to families.

Counseling↗