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Biomedical subjects

J Martin

Publications and source records attributed to J Martin.

At least 37 records · Page 2Linked to original sources
PubMed2005

Pelvic radiotherapy in patients with hydronephrosis in stage IIIB cancer of the cervix: renal effects and the optimal timing for urinary diversion?

BACKGROUND AND PURPOSE: Many patients with Stage IIIB cervix cancer (Ca) and hydronephrosis will require ureteral stenting. The timing is important as delays or prolonged overall treatment times adversely affect outcome. Our aim was to measure the effect of pelvic radiotherapy (R/T) on renal function and identify a subset of patients at high risk of acute urinary obstruction during R/T. PATIENTS AND METHODS: From 1/1/2000 to 1/1/2002, all patients with Stage IIIB cervix Ca and hydronephrosis were analysed retrospectively. To quantify the impact of pelvic R/T, all eligible patients from 1/7/2002-1/7/2004 had prospectively recorded baseline biochemistry, creatinine clearance and renal ultrasounds; these were repeated weekly to detect any change in renal function or degree of hydronephrosis. RESULTS: 13 eligible patients were analysed retrospectively, 5 with unilateral hydronephrosis with 40% requiring urinary diversion (UD). 8 had bilateral hydronephrosis, with 75% requiring UD; 50% before R/T and 35% during R/T. Average creatinine clearance (CrCl) was 74 mL/min (1.24 mL/s) in unilateral hydronephrosis , bilateral = 52 mL/min (0.87 mL/s), in those stented during R/T it was < 40 mL/min (0.67 mL/s). The resulting break in R/T was 6 and 19 days. In the prospective study, 5 patients were eligible and 4 consented. 75% had unilateral hydronephrosis and did not require UD with an average CrCl = 71 mL/min (1.19 mL/s). 1 patient with bilateral hydronephrosis had a CrCl of < 20 mL/min (0.33 mL/s) with bilateral stents placed before R/T. CONCLUSIONS: Patients with bilateral hydronephrosis and a low CrCl < 50 mL/min (0.84 mL/s) should be considered for elective UD prior to R/T. Pelvic R/T did not induce any deterioration in renal function or degree of hydronephrosis.

Acute Kidney Injury↗
PubMed2005

Evaluation of in vitro effects of natural substances of plant origin using a model of protein glycoxidation.

In an in vitro model with purified porcine aspartate aminotransferase (AST, EC 2.6.1.1) as the protein, the effects of phenolic antioxidants of plant origin (arbutin, methylarbutin, ferulic and isoferulic acids, o-coumaric and p-coumaric acids, quinic acid), flavonoids (baicalin and baicalein), and of hydroxycitric acid (HCA) at 0.5-50 mM concentration on the enzyme activities and on its glycation by 50 mM D-fructose as the glycating agent were studied. During incubation with AST at 37 degrees C up to 24 days, fructose alone decreased AST activities as a result of protein glycation. In the absence of fructose, 50 mM phenolic compounds gradually decreased AST activity, while no or a weak effect of individual compounds was found at 3 mM concentration. A direct negative effect on AST was pronounced with ferulic acid. On the other hand, beneficial influences of phenolic compounds on glycation of AST by fructose were found mostly at 3 mM concentration. Effects on glycation were vague at 50 mM concentration, probably due to a combination of direct negative influences and antiglycation effects of individual compounds. No effect, neither positive nor negative, on AST activity and protein glycation, was found with quinic acid. The flavonoid baicalin and its aglycon baicalein rapidly decreased the in vitro activity of the enzyme in all concentrations used (0.5-3 mM), and no beneficial effects of the compounds on glycation of the enzyme by fructose were found. The influence of HCA on glycation was concentration-depended, ranging from beneficial inhibition of glycation at 2.5 mM concentration to a strong decrease in AST activity at 10 mM HCA. Both the beneficial and undesirable effects of natural antioxidants should be considered in case they are used as antiglycation factors. The results obtained can contribute to the evaluation of quality of various generally recommended antioxidants.

Animals↗
PubMed2005

Modified anthrax fusion proteins deliver HIV antigens through MHC Class I and II pathways.

T cell-based HIV vaccine candidates have focused on eliciting both CD4- and CD8-mediated responses. One challenge in vaccine development is the successful introduction and presentation of exogenous antigen to elicit an immune response. Modified bacterial toxins have been studied extensively as intracellular delivery agents because of their unique capability to translocate antigen across the cell membrane without affecting cell viability. Modified anthrax toxin lethal factor (LFn) fusion protein is able to effectively induce anti-HIV cytotoxic T lymphocytes in the absence of protective antigen (PA) and is being evaluated as a vaccine candidate. Here we describe, for the first time, the processing and presentation of LFn fusion proteins by the MHC Class II pathway. The ability of LFn--HIV to induce both CD8- and CD4-mediated responses may have relevance in current approaches to vaccine design. Furthermore, the translocation and presentation of antigens occurs in the absence of PA, which proposes a modified molecular mechanism of antigen presentation by the anthrax toxin model. Additionally, we found that LFn--HIV is specific and sensitive in detecting HIV-specific CD4(+) and CD8(+) T cell responses in T cell assays, further broadening the value of this antigen delivery system as a useful immunologic tool.

Antigen Presentation↗
PubMed2005

Anomalous conductance quantization in carbon nanotubes.

Conductance measurements of carbon nanotubes containing gated local depletion regions exhibit plateaus as a function of gate voltage, spaced by approximately 1e(2)/h, the quantum of conductance for a single (nondegenerate) mode. Plateau structure is investigated as a function of bias voltage, temperature, and magnetic field. We speculate on the origin of this surprising quantization, which appears to lack band and spin degeneracy.

Journal Article↗
PubMed2005

[Necessity and problems with case-related costing for intensive care patients].

To evaluate whether a German refined diagnosis-related groups (GR-DRGs)-based reimbursement of hospitals/departments covers costs per case, total cost per case accounting is necessary. The aim of the present paper is to delineate the necessity and problems with costs per case accounting for intensive care medicine. The new performance category 8-980 "complex intensive care treatment", in force from 2005 onwards, was integrated into the OPS catalogue to document intensive care work. Whether this will lead to more achievement-oriented cost accounting, has to be demonstrated by the calculations of the institute for reimbursement in hospitals. Basic financing of hospital allowance on a daily basis should be supplemented by extra charges due to analytical concepts of personnel share and to cost-consuming organ replacement procedures. This might lead to a more achievement-oriented cost accounting per case in the ICU.

Costs and Cost Analysis↗
PubMed2005

A two-year prospective study of the health-related quality of life of children with chronic illness--the parents' perspective.

The aim of this study was to assess prospectively changes in the health-related quality of life (HRQL) of children and adolescents with diabetes, asthma or cystic fibrosis (CF). One hundred and twenty-two parents of children aged 10-16 years with asthma, diabetes, or CF were recruited from specialist paediatric clinics. Parents described their children's HRQL using the Child Health Questionnaire (PF98) at baseline, 6, 12, 18 and 24 months post-baseline. They reported that the general health of children with CF was significantly worse than that of children with asthma and diabetes at baseline. In other domains there were few differences between the HRQL of children in the three groups. In several domains, the HRQL of children with asthma or diabetes improved over the 2 years of the study. This improvement was less evident for children with CF.

Adolescent↗
PubMed2005

Use of a nitrogen arm-stabilized endoscopic microdriver in neuroendoscopic surgery.

Stabilization and manipulation of instruments in endoscopic neurosurgery has traditionally been a manual task. Conventional self-retaining retractors have failed to provide reliable fixation for endoscopic procedures. Most surgeons rely on a team approach to endoscopy with one individual controlling the endoscope while the other manipulates instruments within the field of view. This two-surgeon approach is manpower intensive and not an option at many facilities. Recently developed technology provides the independent practitioner with another option. Several nitrogen-powered stabilizing arms have been introduced which decrease or eliminate problems with post-positioning drift. To facilitate fine maneuvering of the endoscope, a new positioning arm is available with an incorporated microdriver capable of sub-millimeter adjustments. We present an illustrative case of the utility of this device in selected endoscopic procedures.

Adolescent↗
PubMed2005

Managing waiting time for radiotherapy: a single machine unit experience.

Waiting time (WT) for radiotherapy (RT) is a significant clinical problem. This paper examines various strategies for managing WT for patients treated with radical and palliative intent in the new setting of a rural single machine unit in Australia. Cohorts of patients undergoing both radical and palliative RT in Bendigo had their WT prospectively recorded. Matched cohorts from the hub centre (Peter MacCallum Cancer Centre, Melbourne) treated with palliative intent were also collated. Strategies implemented included a devoted priority meeting, palliative points system, and reallocation of appointment times. The audit was to continue until best practice guidelines were bettered. Three cohorts of patients were compared. There is a significant trend for increasing numbers of patients treated per month since the centre opened (P < 0.0001). The ratio of palliative to radical intent patients remained stable between 46 and 52%. Mean WT for palliative RT reduced from 25 days in the first cohort to 7 days in the final cohort (P < 0.0005). Waiting time for palliative RT was initially longer at Bendigo than the hub centre (P < 0.0005), but by the final cohort there was a non-significant difference favouring the Bendigo cohort (P = 0.26). Waiting time for radical treatment also improved throughout the three cohorts in Bendigo (P < 0.0005). A number of new strategies have successfully resulted in the abolition of lengthy WT for RT in Bendigo despite the increasing demand for the RT service.

Analysis of Variance↗
PubMed2005

Playground safety in South Western Sydney.

OBJECTIVE: Recognition of the cost of injuries sustained in playgrounds has led to the development of Australian/New Zealand Standards for playground safety. This study assesses compliance of public playgrounds in South Western Sydney with the current Standards. METHODS: Playgrounds in South Western Sydney were randomly audited for compliance with Australian/New Zealand Standards for playground equipment pertaining to fall height, type of undersurface material, adequacy of maintenance of undersurface materials and adequacy of the safe fall zone. Comparisons were made with an audit of playgrounds in New South Wales undertaken in 1995 by Kidsafe. RESULTS: Of the 257 pieces of equipment from 87 playgrounds audited, only three (3.4%) playgrounds and 65 (25.3%) pieces of equipment complied with all criteria assessed. Compared with the 1995 study, there has been a significant improvement in equipment complying with height standards (84.4% vs 72.2%, P < 0.0001) and appropriate undersurface material (66.8% vs 45.4%, P < 0.0001). Pinebark is now the most common appropriate undersurface material used but is poorly maintained, particularly in high-traffic areas. Of 131 pieces of equipment with an appropriate undersurface material, only 38 (29%) had an adequate safe fall zone. CONCLUSIONS: Improvements in playground safety have occurred; however, very few playgrounds meet the Australian/New Zealand Standards. Compliance with Standards pertaining to maintenance of undersurface materials and safe fall zone is poor. Mechanisms need to be developed to support councils in the upgrading and maintenance of existing playgrounds.

Accident Prevention↗
PubMed2005

Antireflux surgery for Barrett's esophagus: comparative results of the Nissen and Collis-Nissen operations.

Using a Collis-Nissen repair instead of a standard Nissen fundoplication to treat the reflux disease of Barrett's esophagus is controversial. This paper compares the Nissen and Collis-Nissen operations when treating Barrett's esophagus. Thirty-three patients with documented Barrett's esophagus (male : female, 26 : 7, median age, 48.8 years) had a Nissen fundoplication during 1976-1989. Fifty-one patients (male : female = 41 : 10, median age = 53.2 years) underwent a Collis-Nissen operation between 1990 and 1999. Clinical assessments, esophagogram, radionuclide emptying, manometry, 24-h pH study, and endoscopy were obtained pre- and postoperatively. There was no operative death in either group. Median follow-up was 8.0 years for the Nissen group and 6.5 years for the Collis group. Postoperative reflux symptoms were more frequent in the Nissen group (52%) when compared to the Collis group (7%, P < 0.001). These symptoms correlated with the 24-h pH recordings revealing an increased acid exposure in the Nissen group (3.4%) as opposed to 1% in the Collis group (P = 0.003). Endoscopy revealed mucosal erosions and ulcers in 39% of patients receiving a standard Nissen repair while these damages were seen in 7% of patients who were offered an elongation gastroplasty with a total fundoplication (P = 0.007). The cumulative success rate was 83% for the Nissen group and 100% for the Collis group at 5 years, and 63% versus 90% at 10 years (Log-rank test, P = 0.004). The Collis-Nissen fundoplication provides better reflux protection for Barrett's patients than a standard Nissen repair. It lowers the risk of fundoplication failure.

Barrett Esophagus↗
PubMed2005

The safety of dosing dalteparin based on actual body weight for the treatment of acute venous thromboembolism in obese patients.

Data evaluating the safety of using weight-based low-molecular-weight heparin in the treatment of obese patients with acute venous thromboembolism are limited. The product monograph of dalteparin suggests the maximum dose should be limited to 18,000 U subcutaneously once daily. There are no specific data regarding the risk of recurrence or bleeding in patients given dalteparin in a weight-based dose of 200 IU kg(-1). We report a retrospective chart review of 193 obese patients who weighed more than 90 kg and who received dalteparin at or near to 200 IU kg(-1) actual body weight for 5-7 days for acute venous thromboembolism with 90 day follow-up information. Of the patients, 77% had idiopathic venous thromboembolism, 16% had an underlying malignancy, and 7% had a transient risk factor. Warfarin was initiated within 2 days with a target International Normalized Ratio range of 2.0-3.0. All patients were followed for 12 weeks post diagnosis. Only two patients had a major hemorrhage, 4 and 8 weeks from diagnosis. This study supports the safety of dosing dalteparin based on actual body weight in obese patients.

Adult↗