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Biomedical subjects

P Robinson

Publications and source records attributed to P Robinson.

At least 73 records · Page 4Linked to original sources

Relationship of MRI and clinical staging to outcome in invasive bladder cancer treated by radiotherapy.

AIM: To compare MRI and clinical staging of invasive bladder cancer prospectively and identify additional prognostic features on MRI before radiotherapy. METHODS AND MATERIALS: 143 patients with a pathological diagnosis of transitional cell carcinoma underwent MRI (1.0 T) of the abdomen and pelvis before radical radiotherapy. Tumour size, site, degree of infiltration, presence of adenopathy and hydronephrosis were assessed and an appropriate radiological stage assigned. Following radiotherapy all patients received regular cystoscopic follow-up. Date of first relapse and date of death were recorded. RESULTS: The median follow-up was 2.8 years for survivors. Those patients upstaged from T2a clinically to T3b on MRI had a significantly worse outcome (P = 0.0078). In univariate analysis a number of MRI features were significantly associated with adverse outcome: tumour size, circumferential tumour extent, and presence of hydronephrosis (all P < 0.05). After adjustment for clinical T stage and histological grade, all these MRI features and the MRI T stage were found to confer additional prognostic information in predicting early disease relapse and death (P < 0.05). CONCLUSION: This study demonstrates that MRI before radiotherapy provides valuable additional prognostic information compared to clinical staging.

Aged↗

Interferon-gamma expression in jejunal biopsies in experimental human cryptosporidiosis correlates with prior sensitization and control of oocyst excretion.

To investigate the role of interferon (IFN)-gamma in human cryptosporidiosis, jejunal biopsies from experimentally infected volunteers and chronically infected AIDS patients were examined for IFN-gamma expression by in situ hybridization. IFN-gamma expression was compared with oocyst excretion, baseline serum anti-Cryptosporidium antibody, and symptoms. IFN-gamma mRNA was detected in biopsies from 13 of 26 volunteers after experimental infection but not in biopsies taken before C. parvum exposure or in biopsies from patients with AIDS-associated cryptosporidiosis. After challenge, 9 of 10 volunteers with baseline C. parvum antibody produced IFN-gamma, compared with 4 of 16 volunteers without baseline antibody (P<.01). Furthermore, IFN-gamma mRNA was detected in 9 of 13 volunteers who did not excrete oocysts, compared with 4 of 13 with organisms (P<.05). Thus, expression of IFN-gamma in the jejunum was associated with prior sensitization and absence of oocyst shedding. IFN-gamma production may explain the resistance to infection noted in sensitized persons but may not be involved in control of human primary infection.

AIDS-Related Opportunistic Infections↗

Transforming growth factor beta1 is expressed in the jejunum after experimental Cryptosporidium parvum infection in humans.

Biopsies from volunteers challenged with Cryptosporidium parvum were examined for transforming growth factor beta1 (TGF-beta1). None of the prechallenge biopsies exhibited TGF-beta. Seven of 12 volunteers with oocyst shedding expressed TGF-beta versus 2 of 13 volunteers without detected oocysts. The association of TGF-beta expression with oocyst excretion and the timing of symptoms suggests that TGF-beta mediates intestinal healing.

Animals↗

Perioperative and late stroke rates of carotid endarterectomy contralateral to carotid artery occlusion : results from a randomized trial.

BACKGROUND AND PURPOSE: Several previous studies have reported the benefits of carotid endarterectomy (CEA) contralateral to carotid occlusion with mixed results, but none of these were randomized except for the North American Symptomatic Carotid Endarterectomy Trial. The purpose of this study was to analyze the results of surgery in patients with contralateral carotid artery occlusion in a randomized trial in which randomization was done according to the method of closure. METHODS: In 399 CEAs (357 patients) that were randomized into primary closure versus patching, 49 had contralateral occlusion. Strokes were designated as ipsilateral if they arose from the same CEA side and contralateral if they arose from the occluded side. A Kaplan-Meier analysis was used to estimate perioperative strokes and stroke-free survival in patients with contralateral occlusion (group A) versus those without contralateral occlusion (group B). RESULTS: Demographic characteristics and mean follow-up for both groups were similar (group A, 40 months; group B, 33 months). Group A had a higher incidence of contralateral transient ischemic attacks (TIAs) (12.2% versus 0.9%; P<0.0001), contralateral strokes (2% versus 0%; P=0.025), and combined contralateral TIAs/strokes (14.3% versus 0.9%; P<0.0001). The rates for perioperative and all strokes (operative and late) were 2% and 4. 1% (2% ipsilateral and 2% contralateral strokes) for group A and 2. 9% and 3.4% (all ipsilateral) for group B (P=0.60 and 0.85, respectively). The rates for perioperative and all TIAs were 0% and 14.3% for group A versus 2.6% and 6.3% for group B (P=0.918 and P=0. 08, respectively). The rates for perioperative and all neurological events (TIA and stroke) were 2% and 18.4% for group A and 5.4% and 9. 7% for group B (P=0.27 and 0.113, respectively). The cumulative stroke-free survival rates at 5 years were 84% for group A and 77% for group B (P>0.1). The cumulative stroke-free survival rates at 5 years for symptomatic and asymptomatic patients in group A and group B were also similar. The perioperative and late deaths were similar for both groups (group A, 8%; group B, 14%). CONCLUSIONS: Group A had a higher incidence of contralateral TIAs and strokes than group B; however, the perioperative and all late stroke rates and survival rates of CEA were comparable in patients with and without contralateral occlusion.

Adult↗

An evaluation of a network for professional development in child and adolescent mental health in rural and remote communities.

In 1998 a telemedicine network was established in South Australia and the Northern Territory to deliver educational material to professionals working in child and adolescent mental health in remote areas. The network involved a wide range of health professions, from psychiatrists to psychologists and social workers. The first 12 months of network activity were evaluated by quantitative and qualitative techniques. Four sources of data were used: an activity log, questionnaires, interviews and action research. A total of 36 telemedicine sessions were held, ranging in duration from 45 to 90 min (average 56 min) and involving a total of 45 different professionals, who participated an average of four times each (range 1-15). The most common types of session were case discussions (47%), followed by specialist seminars (36%) and administrative and introductory sessions (17%). The benefits of the network included: networking and peer support; improved efficiency and reduced travel costs; and improved efficiency of health services. The problems included: costs; lack of access to technical support; and the need for staff induction and training.

Adolescent↗

What do GPs need to know? The use of knowledge in general practice consultations.

In the course of the consultation in primary care, the general practitioner integrates knowledge of different types that are drawn from different sources. As a consequence of the way practitioners develop expertise, this use of knowledge is often hidden from the conscious mind of the practitioner and often hidden from direct observation. On the other hand, understanding of this use of knowledge is crucial to several necessary developments of the profession of general practice. A method involving collaboration between researcher and practitioner sheds new light on this knowledge-in-use.

Clinical Competence↗

Meningococcal disease and the law: does non-notification really happen?

In Victoria, legislation clearly makes the notification of clinical or confirmed cases of meningococcal disease mandatory. Statistical modelling suggests that meningococcal disease is significantly under-notified, and that incorrect codes might be being ascribed to some in-patient episodes. The aims of this study were (i) to test the assumption that cases identified as non-notified cases were true cases, and (ii) to identify the reasons for non-detection on the hospital separation database and non-notification to the infectious diseases unit. Of 26 cases not identified on the in-patient dataset, the main causes were either being given completely incorrect ICD-9-CM codes (11 cases) or being given codes for a different type of meningitis (8 cases). Of 29 non-notified admissions, most were clinically (17) or microbiologically (6) confirmed cases, although 5 were coded in error and were not cases of meningococcal disease. Therefore, although the allocation of incorrect ICD-9-CM codes at separation was a major reason for discrepancy, non-notification was a real and recent problem. It is also possible that some clinical staff did not understand the relationship between Neisseria meningitidis and meningococcal disease, the public health implications of this infection, or the law relating to it.

Disease Notification↗

Occupational health practice in New Zealand.

On the basis of the national un-funded liability for work injuries and illnesses, and comparisons of health outcome and cost data to a benchmark, it can be concluded that occupational health practice in New Zealand is deficient. This deficiency persists despite recent legislative reforms and is due to a combination of Accident Rehabilitation and Compensation Insurance Corporation, health professional and industrial factors. It is clear that a comprehensive corrective strategy is needed to attend to: the up-skilling of health case managers and the medical profession in concert; and, to encouraging employers to introduce comprehensive occupational health programmes.

Benchmarking↗

Single dose pharmacokinetics and bioavailability of nevirapine in healthy volunteers.

The results of two randomized, single-dose, crossover bioavailability studies are presented which describe the pharmacokinetics and oral bioavailability of nevirapine, a novel nonnucleoside antiretroviral drug. In the first study 12 healthy male volunteers received nevirapine 15 mg via short-term i.v. infusion or orally as a 50 mg tablet or reference solution (50 mg/200 mL). Following the i.v. dose, nevirapine had a low systemic clearance (Mean +/- S.D., Cl = 1.4 +/- 0.3 L/h) and a prolonged elimination phase (t(1/2beta) = 52.8 +/- 14.8 h; MRT = 81.4 +/- 22.4 h). Nevirapine absolute bioavailability was 93 +/- 9% and 91 +/- 8% for the tablet and oral solution, respectively. In the second study, 24 healthy male volunteers were administered nevirapine as a 200 mg production-line tablet or oral reference solution (200 mg/200 mL). There was no significant difference in bioavailability between the tablet and reference solution. Overall, comparison of the pharmacokinetic parameters between the 50 and 200 mg doses indicates that nevirapine is well absorbed at clinically relevant doses. The absorption profiles using deconvolution revealed no evidence of differential enzyme induction between the two doses or routes of administration following a single dose.

Administration, Oral↗