PubMed Health⌕ Search

Biomedical subjects

John Collins

Publications and source records attributed to John Collins.

At least 37 records · Page 2Linked to original sources
PubMed2004

Canadian access to hormonal contraceptive drug choices.

On October 29, 2002, Health Canada issued Guidance for Industry: Clinical Development of Steroidal Contraceptives Used by Women. The original draft of this guideline, published July 4, 2001, included recommendations for clinical trials in excess of those required in Europe and the United States. The proposed requirements, which reflected Health Canada's views, had the potential to discourage contraceptive research in Canada and to block registration of new products. To evaluate the impact of Canada's hormonal contraceptive regulation, a comparative analysis of the availability of products in various countries was performed, along with an evaluation of the time required from submission to approval of a new drug. Women in Canada have access to 35% of the contraceptive products available worldwide and to 37% of the hormonal contraceptives available worldwide, compared with 58% and 59% respectively, in the United States; 52% and 54% respectively, in the United Kingdom; 44% and 54%, respectively, in France; and 44% and 50% respectively, in Sweden. Regarding the more recent contraceptive products available worldwide, women in Denmark have the most choices (67% of available products), whereas women in Canada have the least (only 22% of available products). Eleven of 12 oral contraceptive products recently approved in other countries have either not been submitted for approval in Canada or remain in the Canadian regulatory process. Although the time-to-approval period in Canada, for drugs in general, is 6 months longer than in the United States, the mean lag time for 6 contraceptive products is 29.6 months as of January 1, 2004, and no oral contraceptives have been approved in Canada since 1997.

Canada↗
PubMed2004

Predictors of baseline peritoneal transport status in Australian and New Zealand peritoneal dialysis patients.

BACKGROUND: Factors that predict peritoneal transport status in peritoneal dialysis (PD) patients are poorly understood. The aim of the present study is to determine these factors in Australian and New Zealand incident PD patients. METHODS: The study included all patients on the Australian and New Zealand Dialysis and Transplant Registry who started PD therapy between April 1, 1991, and March 31, 2002, and underwent a peritoneal equilibration test (PET) within the first 6 months. Predictors of peritoneal transport category and dialysate-plasma creatinine ratio at 4 hours (D-P Cr 4h) were assessed by multivariate ordinal logistic regression and multiple linear regression, respectively. RESULTS: A total of 3,188 patients were studied. Mean D-P Cr 4h was 0.69 +/- 0.13. High transport status was associated with older age (adjusted odds ratio [OR], 1.08 for each 10 years; 95% confidence interval [CI], 1.03 to 1.13), Maori and Pacific Islander racial origin (OR, 1.48; 95% CI, 1.13 to 1.94), and normal body mass index (BMI; < 18.5 kg/m2: OR, 0.90; 95% CI, 0.65 to 1.24; BMI of 18.5 to 25 kg/m2: OR, 1 [reference]; BMI of 25 to 30 kg/m2: OR, 0.81; 95% CI, 0.70 to 0.95; BMI > 30 kg/m2: OR, 0.71; 95% CI, 0.58 to 0.86), but was not independently predicted by sex, diabetes, other comorbid diseases, smoking, previous hemodialysis therapy or transplantation, or residual renal function. Similar results were found when peritoneal permeability was modeled as a continuous variable (D-P Cr 4h). CONCLUSION: In Australian and New Zealand PD patients, higher peritoneal transport status is independently associated with racial origin, older age, and lower BMI. The diversity of peritoneal transport characteristics in different ethnic populations suggests that additional validation of PET measurements in various racial groups and study of their relationship to patient outcomes are warranted.

Adult↗
PubMed2004

Effective bladder sparing therapy with intra-arterial cisplatin and radiotherapy for localized bladder cancer.

PURPOSE: We evaluated the feasibility and efficacy of the organ preserving strategy of intra-arterial cisplatin and concurrent radiotherapy for localized bladder cancer. MATERIALS AND METHODS: Bladder preservation has been pursued over the decades in treatment regimens featuring radiotherapy alone or in conjunction with single or multiagent chemotherapy. The chemotherapy has consisted almost exclusively of intravenously administered drugs. There are theoretical and clinical data demonstrating a higher concentration of cisplatin within tumors following intra-arterial as opposed to intravenous delivery. This study was performed to evaluate whether this increased concentration would enhance radiosensitization and thereby increase the success of bladder preservation. RESULTS: We report on our prospectively collected experience during 15 years of treating 200 patients with localized bladder cancer using this regimen of 3 courses of intra-arterial cisplatin integrated with pelvic radiotherapy and reserving cystectomy for salvage as required. We report on the efficacy in terms of complete response rate, ultimate tumor-free bladder preservation, overall survival and patterns of failure. We detail the acute and chronic toxicity observed to date. CONCLUSIONS: This strategy has resulted in a durable high complete response rate and overall tumor-free bladder preservation rate of 75% while maintaining a survival comparable to that achieved with cystectomy. These results corroborate the hypothesis that intra-arterial administration of cisplatin enhances radiosensitization during pelvic radiotherapy.

Adenosarcoma↗
PubMed2004

Low vision services in South Devon: a multi-agency, multi-disciplinary approach.

Since 1994, the Low Vision Service in South Devon has been provided by a multi-agency, multi-disciplinary team. The team comprises of staff from Devon Social Services Sensory Team, Optima Low Vision Services Ltd, Royal National Institute for the Blind (RNIB) Manor House, Devon and Torbay Special Education Services and South Devon Healthcare Trust. In the 9 years of operation this service has been independently audited twice for patient satisfaction levels and compliance level in the use of low vision aids (LVAs). The results of the most recent service audit questionnaire reveal a high and constant patient satisfaction level with 92% of patients who answered the question reporting that the service was sufficient to meet their needs. The number of patients who used LVAs at least weekly was 88% of those answering the question. Plans for the future expansion of the service include the further development of interdisciplinary working.

Charities↗
PubMed2004

SOGC clinical practice guidelines: Canadian contraception consensus.

OBJECTIVE: To provide guidelines for health-care providers on the use of contraceptive methods to prevent pregnancy and sexually transmitted diseases. OUTCOMES: Overall efficacy of cited contraceptive methods, assessing reduction in pregnancy rate, risk of infection, safety, ease of use, and side effects; the effect of cited contraceptive methods on sexual health and general well-being; and the cost and availability of cited contraceptive methods in Canada. EVIDENCE: Medline and the Cochrane Database were searched for articles in English on subjects related to contraception, sexuality, and sexual health from January 1988 to March 2003, in order to update the Report of the Consensus Committee on Contraception published in May-July 1998. Relevant Canadian Government publications and position papers from appropriate health and family planning organizations were also reviewed. VALUES: The quality of the evidence is rated using the criteria described in the Report of the Canadian Task Force on the Periodic Health Examination. Recommendations for practice are ranked according to the method described in this Report.

Canada↗
PubMed2003

Adjuvant endocrine therapy compared with no systemic therapy for elderly women with early breast cancer: 21-year results of International Breast Cancer Study Group Trial IV.

PURPOSE: Increasing numbers of older women are affected by early breast cancer, because of prolonged life expectancy and the increasing incidence of breast cancer with age. The role of adjuvant therapy for this population is still a matter of debate. We reviewed the long-term outcome of a mature trial comparing endocrine treatment versus no adjuvant therapy in older women with node-positive breast cancer. PATIENTS AND METHODS: From 1978 to 1981, 349 women 66 to 80 years of age with pathologically involved lymph nodes after total mastectomy and axillary clearance were randomly assigned to receive 12 months of adjuvant tamoxifen plus low-dose prednisone (p+T) or no adjuvant therapy. Three hundred twenty patients were eligible. RESULTS: At 21 years' median follow-up, 1 year of p+T significantly prolonged disease-free survival (DFS; P =.003) and overall survival (P =.05; 15-year DFS, 10% +/- 3% v 19% +/- 3%; hazard ratio, 0.71; 95% CI, 0.58 to 0.86). When comparing competing causes of failure (breast cancer recurrence and deaths before breast cancer recurrence), p+T was far superior in controlling breast cancer recurrence (P =.0003), but the improvement was seen mainly in soft tissue sites. Conversely, patients in the p+T group were more likely to die before a breast cancer recurrence (P =.03). CONCLUSION: This trial demonstrates that significant treatment benefits continue to be observed in older patients treated for 1 year with p+T. Despite issues relating to competing causes of failure, older breast cancer patients can benefit from treatment and should be considered for trials of adjuvant systemic therapy.

Aged↗
PubMed2003

Microfluidic flow transducer based on the measurement of electrical admittance.

A new flow transducer for measuring the flow rate of a conducting fluid in a microchannel is reported. In this paper, the measure of flow of such fluid under laminar flow conditions based on the change of electrical admittance is established with the aid of a pair of electrodes parallel to the line of flow in a glass-PDMS microfluidic device. This flow sensor is simple in design and can be integrated to most of the microfluidic platforms. The effect of flow rate of the electrolyte, the frequency of the applied ac voltage, the voltage applied across the detector electrodes, and the conductivity of the electrolyte are varied to optimize for high sensitivity. The optimized values are then used to demonstrate the measurements of very low flow rates (<1 nL s(-1)). This flow sensor can be extended towards the measurement of chemical and biochemical buffers and reagents.

Journal Article↗
PubMed2003

Access to dialysis in New Zealand renal services.

AIM: To assess the equity of access to dialysis treatment in New Zealand renal services. METHODS: All patients with chronic renal failure assessed by NZ renal services for whom a decision regarding dialysis was made in the years 1997 and 1998 were entered into the study. Information collected included patient demographics, cause of renal failure, scores for comorbidity and activities of daily living (ADL), renal centre and dialysis decision. RESULTS: Records were available for 823 patients, of whom 710 were offered dialysis and 676 accepted treatment. Compared with those who accepted an offer of dialysis, those not offered treatment were older (67.4 vs 53.3 years, p <0.001), and had higher scores for comorbidity (340 vs 128, p <0.001) and ADL (150 vs 32, p <0.001), but there was no difference in primary disease incidence. Patients at one centre were referred with significantly higher average comorbidity, and at two centres with significantly different ADL scores, than those referred to the reference centre. The acceptance rate was significantly lower at one centre when adjusted for age, ethnicity, gender, and comorbidity and ADL scores. CONCLUSIONS: Of all referred patients, 13.7% were not offered dialysis treatment. They had significantly higher comorbidity, and were older and more disabled than those patients offered treatment. There was one centre with a significantly lower adjusted acceptance rate.

Activities of Daily Living↗
PubMed2003

Decreased immunoreactivity for p27 protein in patients with early-stage breast carcinoma is correlated with HER-2/neu overexpression and with benefit from one course of perioperative chemotherapy in patients with negative lymph node status: results from International Breast Cancer Study Group Trial V.

BACKGROUND: The objective of this study was to clarify the prognostic and predictive value of immunoreactivity for the cyclin-dependent kinase inhibitor p27(Kip1) in patients with early-stage breast carcinoma and to investigate its relation with clinicopathologic features and other markers. METHODS: Immunoreactivity for p27 protein was analyzed on tumor slides from 461 patients who were enrolled in the International Breast Cancer Study Group (IBCSG) Trial V (median follow-up, 13 years), including 198 patients with lymph node negative disease and 263 patients with lymph node positive disease. Tumors with < 50% immunoreactive neoplastic cells were considered low expressors. Immunoreactivity for p27 was correlated with several clinicopathologic characteristics. Disease free survival (DFS) and overall survival were analyzed according to p27 immunoreactivity and treatment group. RESULTS: In the lymph node negative population, decreased p27 immunoreactivity was associated with higher tumor grade (P = 0.001) and HER-2/neu overexpression (P = 0.04). In the lymph node positive population, low p27 expression was associated with higher tumor grade (P = 0.01), low expression of thymidylate synthase (P = 0.001), and higher Ki-67 expression (P = 0.007). DFS was not significantly different according to p27 status in either lymph node negative patients (10-year DFS: low p27 expression, 53% +/- 5%; high p27 expression, 55% +/- 5%) or in lymph node positive patients (10 year DFS: low p27 expression, 33% +/- 4%; high p27 expression, 32% +/- 4%). However, in the lymph node negative population, the benefit of one course of perioperative chemotherapy with cyclophosphamide, methotrexate, and 5-fluorouracil was confined exclusively to patients with tumors that showed reduced p27 immunoreactivity (P = 0.03; test for interaction). CONCLUSIONS: This analysis indicates that p27 immunoreactivity has little if any prognostic value in patients with early-stage breast carcinoma. However, these findings suggest that, in patients with breast carcinoma who have negative lymph node status, reduced p27 immunoreactivity is associated with HER-2/neu overexpression and may be predictive of a benefit from the early administration of adjuvant chemotherapy.

Adult↗
PubMed2003

Ki-67 expression in breast carcinoma: its association with grading systems, clinical parameters, and other prognostic factors--a surrogate marker?

BACKGROUND: The number of mitoses and, thus, the proliferative capacity of a tumor is one of the most crucial variables for tumor grading. The Ki-67 nuclear antigen may be considered as an alternative to mitotic counts in grading schemes and as a single parameter that can be used in fine-needle aspirates and small biopsies. METHODS: Immunohistochemistry using the anti-Ki-67 antibody MIB-1 was performed on 434 breast carcinoma specimens from the International Breast Cancer Study Group (formerly Ludwig) Trial V. Three groups based on Ki-67 percent were used to replace the mitotic counts component in the Nottingham grade (NHG) to produce the Nottingham/Ki-67 grade (NKG) and to assess Ki-67 as a single parameter. RESULTS: In both the lymph node positive subgroup and the lymph node negative subgroup, the NKG and Ki-67 group was correlated significantly with Bloom-Richardson grade (BRG), NHG, and Nottingham type. Tumor size in the lymph node negative cohort and estrogen receptor status, progesterone receptor status, and c-erbB-2 expression in the lymph node positive cohort also were correlated significantly with NKG. Ki-67 percentage was correlated significantly with c-erbB-2 expression in the lymph node positive cohort only. NKG was similar to BRG and NHG when it was evaluated for prognostic significance. Patients with higher categoric Ki-67 percentages had worse overall and disease free survival in all groups except for the untreated, lymph node negative group. CONCLUSIONS: Ki-67 detection represents a valuable tool and is a good objective substitute for mitotic counts when used in a grading system. When it is used alone, Ki-67 detection provides valuable information, although it is necessary to combine this with other parameters in the study of core biopsies and fine-needle aspirates.

Breast Neoplasms↗
PubMed2003

The relationship of symptoms and psychological factors to delay in seeking medical care for breast symptoms.

BACKGROUND: The psychological processes involved in the delay between noticing breast symptoms and seeking medical care are not well understood. METHODS: We evaluated 85 women referred to a specialist breast clinic prior to their clinic appointment. We assessed the relationship between delay and the type of breast symptom, immediate emotional response to the symptom, perceived risk of breast cancer, fear of breast cancer treatment, and disclosure of the breast symptom to others. RESULTS: Delay was unrelated to demographic factors but was related to the type of breast symptom; women who had a breast lump waited a significantly shorter time period before visiting the doctor than those without a breast lump. Initial symptom distress on the discovery of the breast symptom was also significantly related to delay. Knowledge of a friend or family member with breast cancer, perceived risk of breast cancer and fear of breast cancer treatment, and disclosure of the symptom to a partner or other person were all unrelated to delay. CONCLUSIONS: The results show the importance of the type of symptom and initial emotional distress in delay and highlight the importance of widening public perceptions of breast symptoms other than breast lumps in order to reduce delay times.

Adaptation, Psychological↗
PubMed2003

Recommendations for the use of icodextrin in peritoneal dialysis patients.

Icodextrin is a starch-derived, high molecular weight glucose polymer, which has been shown to promote sustained ultrafiltration equivalent to that achieved with hypertonic (3.86%/4.25%) glucose exchanges during prolonged intraperitoneal dwells (up to 16 h). Patients with impaired ultrafiltration, particularly in the settings of acute peritonitis, high transporter status and diabetes mellitus, appear to derive the greatest benefit from icodextrin with respect to augmentation of dialytic fluid removal, amelioration of symptomatic fluid retention and possible prolongation of technique survival. Glycaemic control is also improved by substituting icodextrin for hypertonic glucose exchanges in diabetic patients. Preliminary in vitro and ex vivo studies suggest that icodextrin demonstrates greater peritoneal membrane biocompatibility than glucose-based dialysates, but these findings need to be confirmed by long-term clinical studies. This paper reviews the available clinical evidence pertaining to the safety and efficacy of icodextrin and makes recommendations for its use in peritonal dialysis.

Diabetes Complications↗
PubMed2003

Stimulated intra-uterine insemination is not a natural choice for the treatment of unexplained subfertility. Current best evidence for the advanced treatment of unexplained subfertility.

When conventional treatment of unexplained infertility has not been successful, the next choice lies between either gonadotrophin treatment with intrauterine insemination (FSH/IUI) and IVF. Cohort studies indicate that FSH/IUI is less effective while the cost per birth is higher with IVF. The relevant evidence should come from randomized controlled trials, but the results need to be recalculated for the outcome of greatest interest, a singleton live birth. Judged by this standard, FSH/IUI is statistically superior to no treatment, but the effect is small in couples with unexplained infertility. By the same standard, IVF is superior to FSH/IUI treatment, but this benefit is achieved only at considerable cost. The evidence is not robust, comprising only a few trials which involve a minute fraction of the existing patients with unexplained infertility. Current best evidence is consistent with a progression from low-tech to high-tech treatment, but it is not convincing enough to support a rigid management protocol. A large multicentre factorial trial is needed to evaluate the relative value of existing empiric treatments for unexplained infertility.

Clomiphene↗
PubMed2003

Colles fracture, spine fracture, and subsequent risk of hip fracture in men and women. A meta-analysis.

BACKGROUND: In postmenopausal women, a history of any fracture is an important risk factor for a future hip fracture. Whether similar findings apply to aging men remains to be established. We conducted a systematic review and meta-analysis of the literature to compare men and women with respect to the relative risk of hip fracture after a wrist or spine fracture. METHODS: Studies published in full from January 1982 through September 2002 in English, French, or German were identified from the PubMed database and from reference lists of retrieved articles. We included cohort studies that reported fractures associated with minimal trauma of the wrist or spine as a risk factor for a subsequent hip fracture among (white) women and men who were fifty years old or older. Data were extracted by two independent reviewers and were checked for accuracy in a second review. Differences in assessments were resolved by consensus of the two reviewers. RESULTS: Nine cohort studies were included in this meta-analysis: five studies were conducted in the United States and four, in Europe. After homogeneity of association was demonstrated across all studies, a fixed-effects meta-analysis was used to calculate pooled relative risks with 95% confidence intervals. Among postmenopausal women, the relative risks for a future fracture of the hip after a fracture of the wrist or spine were 1.53 (95% confidence interval, 1.34 to 1.74; p < 0.001) and 2.20 (95% confidence interval, 1.92 to 2.51; p < 0.001), respectively. In older men, these relative risks were 3.26 (95% confidence interval, 2.08 to 5.11; p < 0.001) and 3.54 (95% confidence interval, 2.01 to 6.23; p < 0.001), respectively. Fractures of the distal part of the radius increased the relative risk of hip fracture significantly more in men than in women (p = 0.002). The impact of a spine fracture, conversely, did not differ between genders (p = 0.11). Sensitivity analyses with use of random-effects methodology confirmed these findings to be robust. CONCLUSIONS: This meta-analysis suggests that a previous spine fracture has an equally important impact on the risk of a subsequent hip fracture in both genders. The prospective association between a Colles fracture and a subsequent hip fracture, however, is significantly stronger among men than among postmenopausal women. Men with a Colles fracture are at high risk for a future hip fracture and should be evaluated as candidates for preventive measures.

Age Factors↗
PubMed2003

Use of videotaping to assess competencies and course outcomes.

A constant challenge in nursing education is effectively teaching competencies and allowing students to safely practice essential nursing skills. Faculty members must develop sound methods of instruction to achieve program outcomes, which determine program effectiveness, assure professional readiness, and meet accreditation standards. To this end, the use of videotaping is suggested. Videotaping offers a safe way for students to practice skills and develop confidence prior to actual performance. This article reviews the literature on videotaping and discusses videotaping as used at Central Missouri State University baccalaureate school of nursing. Videotaping is a teaching-learning strategy used to help students develop effective communication, physical assessment, and selected psychomotor skills. Videotaping also provides students with a mechanism for detailed instructor feedback to improve performance.

Clinical Competence↗
PubMed2002

Delay in seeking medical care for self-detected breast symptoms in New Zealand women.

AIMS: To investigate the extent of patient delay in new patients with self-detected breast symptoms referred to a specialist breast clinic. To examine the association between delay and sociodemographic factors, the practice of breast self-examination (BSE), how the breast symptom was discovered, and personal experience of breast cancer in family and friends. METHODS: Eighty five women referred to the South Auckland Health Breast Clinic completed a questionnaire and interview after arrival at the clinic and prior to their consultation with the medical specialist. Delay was measured as the time interval between initial self-detection of a breast symptom and first contact with a general practitioner (GP) for evaluation of the symptom. Analysis of patient characteristics and delay time was conducted using Pearson product moment correlations, t-test for independent samples and one way analysis of variance (ANOVA) where appropriate. RESULTS: The median delay time between initial breast symptom detection and seeing a GP was 14 days. Of the total sample of 85 women, 40% had seen their doctor within 7 days, 52% within 14 days, 69% within 30 days, and 14% had waited over 90 days. Delay time was not significantly associated with any sociodemographic factors. No difference in delay time was found between the ethnic groups of European, Maori or Pacific women. No difference in delay was shown between those women who performed regular BSE and those who did not. However, women who discovered their breast symptom by chance or through BSE had a shorter delay time than women experiencing breast pain. Although experience of a friend or family member with breast cancer was not significantly associated with delay, there was a trend for women who had a family member with breast cancer to have a longer delay time before seeing their GP. CONCLUSIONS: This study is the first in New Zealand to investigate the extent of patient delay for women with self-detected breast symptoms and the factors influencing this delay. The majority of women saw their doctor within one month of self-detection of a breast symptom, however 14% delayed over three months before seeing their GP. Women who had a family member with breast cancer tended to respond to their breast symptom by delaying seeking medical attention, suggesting that risk perceptions of developing breast cancer may influence delay times in seeking medical help. Results from this study are taken from women referred by their GP to a specialist breast clinic. Certainly, further clarification of the factors that influence delay involving broader patient groups is vital to the development of public education initiatives aiming to encourage women to seek prompt medical evaluation of breast symptoms.

Adult↗