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Biomedical subjects

G Peterson

Publications and source records attributed to G Peterson.

At least 19 recordsLinked to original sources

Pharmacy diabetes care program: analysis of two screening methods for undiagnosed type 2 diabetes in Australian community pharmacy.

OBJECTIVE: To compare the efficacy and cost-effectiveness of two methods of screening for undiagnosed type 2 diabetes in Australian community pharmacy. METHODS: A random sample of 30 pharmacies were allocated into two groups: (i) tick test only (TTO); or (ii) sequential screening (SS) method. Both methods used the same initial risk assessment for type 2 diabetes. Subjects with one or more risk factors in the TTO group were offered a referral to their general practitioner (GP). Under the SS method, patients with risk factors were offered a capillary blood glucose test and those identified as being at risk referred to a GP. The effectiveness and cost-effectiveness of these approaches was assessed. RESULTS: A total of 1286 people were screened over a period of 3 months. The rate of diagnosis of diabetes was significantly higher for SS compared with the TTO method (1.7% versus 0.2%; p=0.008). The SS method resulted in fewer referrals to the GP and a higher uptake of referrals than the TTO method and so was the more cost-effective screening method. CONCLUSIONS: SS is the superior method from a cost and efficacy perspective. It should be considered as the preferred option for screening by community based pharmacists in Australia.

Australia↗

Resilience and vulnerability of northern regions to social and environmental change.

The arctic tundra and boreal forest were once considered the last frontiers on earth because of their vast expanses remote from agricultural land-use change and industrial development. These regions are now, however, experiencing environmental and social changes that are as rapid as those occurring anywhere on earth. This paper summarizes the role of northern regions in the global system and provides a blueprint for assessing the factors that govern their sensitivity to social and environmental change.

Arctic Regions↗

Simulated effects of dryland cropping intensification on soil organic matter and greenhouse gas exchanges using the DAYCENT ecosystem model.

We present evidence to show that DAYCENT can reliably simulate soil C levels, crop yields, and annual trace gas fluxes for various soils. DAYCENT was applied to compare the net greenhouse gas fluxes for soils under different land uses. To calculate net greenhouse gas flux we accounted for changes in soil organic C, the C equivalents of N2O emissions and CH4 uptake, and the CO2 costs of N fertilizer production. Model results and data show that dryland soils that are depleted of C due to conventional till winter wheat fallow cropping can store C upon conversion to no till, by reducing the fallow period, or by reversion to native vegetation. However, model results suggest that dryland agricultural soils will still be net sources of greenhouse gases although the magnitude of the source can be significantly reduced and yields can be increased upon conversion to no till annual cropping.

Agriculture↗

Comparison of results of percutaneous balloon mitral commissurotomy in patients aged > or = 65 years with those in patients aged < 65 years.

Percutaneous balloon mitral commissurotomy (PBMC) is now first-line therapy in patients with symptomatic mitral stenosis (MS) and favorable valve morphology. Unfortunately, the outcome of Medicare-aged patients undergoing this procedure has not previously been defined. The results of PBMC in 55 patients > or = 65 years old (71 +/- 6 years) with moderate or severe MS were compared with 268 younger patients (47 +/- 10). Preprocedural New York Heart Association functional class and pulmonary pressures did not differ. The older patients had higher blood pressure, were more likely to be in atrial fibrillation and had higher valve scores (9.9 +/- 2.5 vs 8.6 +/- 2.2, p = 0.001). Procedural success was higher in the younger group (71% vs 55%, p = 0.013), with a greater increase in mitral valve area. Complications were similar in both groups and there were no periprocedural deaths. At 6 months a significant improvement in function class was seen in both groups. Restenosis, as assessed by serial echocardiography, occurred at a rate of 0.06 cm(2)/year in both groups, and functional class remained unchanged over 3 years. Event-free survival was similar at 48 months: 76% in the younger group and 69% in the older group. Our data thus demonstrates that PBMC can be safely performed in the Medicare-aged population. Despite less acute success in the older population, complication rates do not differ and decrement in valve area over time occurs at a similar rate. Functional class remains improved and event-free survival over 4 years appears similar in both groups. PBMC should thus be offered to patients with MS and suitable anatomy regardless of their age.

Adult↗

Relativistic effects and two-body currents in (H)((-->)e(')p)n using out-of-plane detection.

Measurements of the (2)H((-->)e,e(')p)n reaction were performed with the out-of-plane magnetic spectrometers (OOPS) at the MIT-Bates Linear Accelerator. The longitudinal-transverse, f(LT) and f(')(LT), and the transverse-transverse, f(TT), interference responses at a missing momentum of 210 MeV/c were simultaneously extracted in the dip region at Q2 = 0.15 (GeV/c)(2). In comparison to models of deuteron electrodisintegration, the data clearly reveal strong effects of relativity and final-state interactions and the importance of two-body meson-exchange currents and isobar configurations. We demonstrate that such effects can be disentangled by extracting these responses using the novel out-of-plane technique.

Journal Article↗

Carboplatin skin testing: a skin-testing protocol for predicting hypersensitivity to carboplatin chemotherapy.

PURPOSE: A high incidence of moderate to severe hypersensitivity reactions (HRs) is noted in patients who have been treated with multiple courses of carboplatin. Presently, there is no reliable way to predict which patients may be at risk for this potentially severe adverse reaction. We developed a skin-test protocol to identify patients at high risk for HR to carboplatin chemotherapy. PATIENTS AND METHODS: Patients undergoing more than seven courses of carboplatin received a 0.02-mL intradermal injection of an undiluted aliquot of their planned carboplatin infusion 1 hour before each course of the agent. A positive skin test was prospectively defined as that resulting in a wheel of at least 5 mm with a surrounding flare. We recently reported a 27% incidence of HRs in patients receiving more than seven courses of carboplatin. These patients served as historical controls for the current study. RESULTS: Forty-seven patients with recurrent ovarian or primary peritoneal carcinoma receiving carboplatin were skin tested. Thirteen of 47 patients (28%) manifested a positive skin test at a median of nine total courses of carboplatin (range, eight to 17 courses). This rate of skin-test positivity was not significantly different from the incidence of documented HR reported in a historical control group (P =.89), suggesting comparable populations. A negative skin test accurately predicted the absence of HR in 166 of 168 courses of chemotherapy. Only two of 47 patients (4%) experienced a HR after a negative skin test. Thus, administering carboplatin only to patients with a negative skin test may result in a significant reduction in HRs relative to historical controls (P =.002). CONCLUSION: An easily performed skin test appears to predict patients in whom carboplatin may be safely administered. Treatment modifications based on the results of skin testing may reduce the incidence of HRs in patients receiving repeated courses of carboplatin.

Antineoplastic Agents↗

Combination chemotherapy with carboplatin and docetaxel in the treatment of cancers of the ovary and fallopian tube and primary carcinoma of the peritoneum.

PURPOSE: Standard chemotherapy for advanced ovarian cancer currently includes a platinum agent (usually carboplatin) and paclitaxel. Because docetaxel is an active agent in platinum-resistant ovarian cancer, it is relevant to evaluate both the toxicity and efficacy of the combination of carboplatin and docetaxel in this clinical setting. PATIENTS AND METHODS: The Gynecologic Oncology Program of the Cleveland Clinic Taussig Cancer Center conducted a phase II trial of carboplatin (area under the concentration-versus-time curve of 6) and docetaxel (60 mg/m(2)), delivered every 3 weeks for six courses, in patients with ovarian and fallopian tube cancers and primary carcinoma of the peritoneum who had either received no prior chemotherapy or had experienced a treatment-free interval of greater than 2 years before developing disease recurrence. RESULTS: Fifty patients (median age, 57 years; range, 44 to 81 years) entered the trial (47 had had no prior chemotherapy). Our toxicity findings included the following: grade 4 neutropenia (64% of patients); hypersensitivity reactions (34%, none requiring discontinuation of therapy); peripheral neuropathy (6%). We had objective responses for 32 of 42 (81%) assessable patients. CONCLUSION: The combination of carboplatin and docetaxel is highly active in ovarian cancer, with the major toxicity being bone marrow suppression. Hypersensitivity reactions are frequent but do not prevent continuation of treatment. With the dose and schedule employed in this trial, neurotoxicity is uncommon. Defining a role for this regimen in routine clinical practice will require the conduct of randomized controlled clinical trials.

Adult↗

Neurotoxicity associated with a regimen of carboplatin (AUC 5-6) and paclitaxel (175 mg/m2 over 3 h) employed in the treatment of gynecologic malignancies.

While the combination chemotherapy regimen of carboplatin (AUC 5-6) and paclitaxel (175 mg/m2 over 3 h) is widely employed in the treatment of ovarian cancer, there are limited data available in the oncologic literature regarding the neurotoxic potential of the program. We retrospectively reviewed the clinical course of 87 patients treated in the Gynecologic Cancer Program of the Cleveland Clinic Taussig Cancer Center to address this important clinical issue. The overall incidence of peripheral neuropathy in this population was 25%, with 13% of women experiencing symptoms > or = grade 2 in severity. We conclude that while neurotoxicity is common following the use of this regimen, significant neurological dysfunction (> or = grade 2) is relatively infrequent.

Adult↗

Actions of the soy phytoestrogen genistein in models of human chronic disease: potential involvement of transforming growth factor beta.

The structural similarity, but non-identity, between 17beta-oestradiol and the soy phytoestrogen genistein suggests that the two compounds will have actions that may be identical in some target biological systems, but different in others. Epidermal growth factor (EGF)-stimulated proliferation of human mammary epithelial cells (that do not express the oestrogen receptor) was significantly suppressed at genistein concentrations (5-10 microM) that are attainable physiologically. Others have shown previously that transforming growth factor beta (TGFbeta) has similar growth-inhibitory effects on human cells. Analysis of the conditioned medium of human mammary epithelial cells exposed to genistein plus EGF showed increased levels of TGFbeta relative to those in the medium of cells exposed to EGF or genistein alone. Related experiments in a primate model of menopause demonstrated that ingestion of soy containing isoflavones was correlated with the suppression of neurodegeneration-relevant phosphorylation of the microtubule-associated protein tau, while intake of Premarin (a hormone replacement therapy that is commonly prescribed for women) was not correlated. The results discussed here indicate that genistein, and probably other related phytoestrogens, have pleiotropic actions, some of which may involve TGFbeta activity.

Animals↗

Acculturation and family functioning are related to health risks among pregnant Mexican American women.

The authors examined the independent and interactive effects of acculturation status and family cohesiveness on a series of psychosocial and medical risk factors of pregnancy among 500 women of Mexican origin. In general, both higher and lower levels of acculturation produced positive or negative psychosocial and healthcare consequences, and the operative relationships depended heavily on the particular outcome chosen. Higher levels of family cohesiveness tended to foster the most constructive health and psychosocial outcomes. However, in some circumstances higher levels of family cohesiveness resulted in less coping and a lower quality of prenatal care for less acculturated women. An important implication of this study is that psychosocial and health information can be obtained through assessments that identify different subgroups of Mexican American women and depend on women's level of acculturation and family cohesiveness. Culturally competent health practitioners or clinicians can conduct these assessments in a prenatal healthcare setting.

Acculturation↗

Comparing frequency of content-bearing words in abstracts and texts in articles from four medical journals: an exploratory study.

BACKGROUND: Retrieval tests have assumed that the abstract is a true surrogate of the entire text. However, the frequency of terms in abstracts has never been compared to that of the articles they represent. Even though many sources are now available in full-text, many still rely on the abstract for retrieval. METHODS: 1,138 articles with their abstracts were downloaded from Journal of the American Medical Association, New England Journal of Medicine, Lancet, and the British Medical Journal. Words were extracted from the articles and their abstracts and the frequency of each word was counted in both sources. Each article and its abstract were tested using a chi-squared test to determine if the words in the abstract occurred as frequently as would be expected. RESULTS: 96% of the abstracts tested as samples of the article they represented. CONCLUSION: In these four journals, the abstracts are lexical, as well as intellectual, surrogates for the documents they represent.

Abstracting and Indexing↗

A randomized controlled trial of filgrastim for the treatment of hospitalized patients with multilobar pneumonia.

This study assessed the safety and efficacy of filgrastim (r-metHuG-CSF [recombinant human methionine granulocyte colony-stimulating factor]), when combined with intravenous (IV) antibiotics, in the treatment of hospitalized adult patients with multilobar community-acquired pneumonia (CAP). Four hundred eighty patients were randomized to receive placebo (n=243) or filgrastim 300 microg/day (n=237), in addition to standard therapy. Treatment with study drug was continued for 10 days, until the peak white blood cell (WBC) count reached 75x109/L, until discharge from the hospital, until death, or until IV antibiotics were discontinued. Study-related observations continued through day 29. Filgrastim increased WBC counts (baseline median, 13.3x109/L; median peak, 43. 8x109/L). The 2 treatment groups were not statistically different with respect to the study end points; however, there was a trend toward reduction of mortality in patients with pneumococcal bacteremia. Although further studies will be required to validate this observation, filgrastim was safe and well tolerated when administered to patients with multilobar CAP.

Adult↗

Declining CA-125 in an ovarian cancer patient with progression of measurable disease: a rational hypothesis for discordant results.

OBJECTIVES: While a declining CA-125 has been demonstrated to be a useful indicator of response to chemotherapy in ovarian cancer, occasional patients will demonstrate discordant results between the level of this antigen and changes in the size of measurable tumor masses. CASE: The patient was seen in the Gynecologic Oncology Program of the Cleveland Clinic Taussig Cancer Center. RESULTS: This patient exhibited a "major response" by CA-125 criteria, significant shrinkage of multiple peritoneal and perirectal implants, but clear progression of a pelvic side wall mass. The discordant results in this case are likely an example of a "mixed response" to the chemotherapy regimen, with the declining CA-125 corresponding to shrinkage of the responding tumor cell population. CONCLUSION: An evaluation of changes in both the serum CA-125 level and measurable masses may represent a more complete analysis of the status of disease in an individual with ovarian cancer.

Adult↗

The antiemetic efficacy of oral ondansetron plus intravenous dexamethasone in patients with gynecologic malignancies receiving carboplatin-based chemotherapy.

PURPOSE: The purpose of this study was to develop a cost-effective prophylactic antiemetic regimen for the prevention of carboplatin-induced emesis. METHODS: Patients being treated in the Gynecologic Cancer Program of the Cleveland Clinic Taussig Cancer Center with a carboplatin-based chemotherapy regimen received a prophylactic antiemetic program consisting of a single dose of oral ondansetron (16 mg) plus intravenous dexamethasone (20 mg) approximately 30 min prior to chemotherapy. Evaluation of the effectiveness of this antiemetic regimen was performed during a single treatment course. RESULTS: A total of 27 patients (median age, 62; range, 41-83) participated in this phase 2 trial. Three patients received single-agent carboplatin, and 24 were treated with either a carboplatin/paclitaxel or carboplatin/docetaxel regimen. The carboplatin AUC dosing level was 4, 5, or 6 in 6, 5, and 16 individuals, respectively. No patient developed vomiting; 2 (7%) individuals experienced nausea during the 24-h period following chemotherapy administration. CONCLUSION: The combination of a single dose of oral ondansetron (16 mg) plus intravenous dexamethasone (20 mg) is an effective prophylactic antiemetic regimen for patients receiving carboplatin-based chemotherapy.

Administration, Oral↗

Phase 2 evaluation of topotecan administered on a 3-day schedule in the treatment of platinum- and paclitaxel-refractory ovarian cancer.

UNLABELLED: PURPOSE; The aim of this study was to investigate the toxicity and efficacy of a more convenient topotecan administration schedule (in contrast to the "standard" 1.5 mg/m(2)/day x 5 days q 21 days) in the management of platinum- and paclitaxel-refractory ovarian cancer. METHODS: Patients with clinically defined platinum- and paclitaxel-refractory ovarian cancer participating in this phase 2 trial conducted by the Gynecologic Cancer Program of the Cleveland Clinic Taussig Cancer Center received topotecan at a dose of 1.5 mg/m(2)/day x 3 days on a 21-day schedule. Both dose escalations and reductions were permitted in the protocol design. RESULTS: A total of 29 patients (median age: 61; range: 43-80) were treated with this modified topotecan schedule. These individuals had received a median of two prior regimens (range: 1-4) (retreatment with a platinum agent or paclitaxel considered a single regimen). The median number of topotecan courses delivered was 3 (range: 1-7). Major toxicity included grade 4 neutropenia (24% of patients); neutropenic fever (10%); grade 3 thrombocytopenia (10%); and requirement for blood transfusion (14%). Dose escalation was possible, and dose reductions required, in 14 and 28% of patients, respectively. Two patients exhibited evidence of a clinically relevant response to treatment. CONCLUSION: This 3-day topotecan program is more convenient and less toxic than the standard 5-day regimen. The limited level of activity observed is not inconsistent with that previously reported for the 5-day topotecan infusion schedule in platinum/paclitaxel-refractory ovarian cancer. Further investigation will be required to document the clinical utility of a 3-day topotecan schedule in a less heavily pretreated and more chemosensitive patient population.

Adult↗

Phase 2 trial of liposomal doxorubicin (40 mg/m(2)) in platinum/paclitaxel-refractory ovarian and fallopian tube cancers and primary carcinoma of the peritoneum.

BACKGROUND: Several studies have demonstrated liposomal doxorubicin (Doxil) to be an active antineoplastic agent in platinum-resistant ovarian cancer, with dose limiting toxicity of the standard dosing regimen (50 mg/m(2) q 4 weeks) being severe erythrodysesthesia ("hand-foot syndrome") and stomatitis. We wished to develop a more tolerable liposomal doxorubicin treatment regimen and document its level of activity in a well-defined patient population with platinum/paclitaxel-refractory disease. METHODS AND MATERIALS: Patients with ovarian or fallopian tube cancers or primary peritoneal carcinoma with platinum/paclitaxel-refractory disease (stable or progressive disease following treatment with these agents or previous objective response <3 months in duration) were treated with liposomal doxorubicin at a dose of 40 mg/m(2) q 4 weeks. RESULTS: A total of 49 patients (median age: 60; range 41-81) entered this phase 2 trial. The median number of prior regimens was 2 (range: 1-6). Six (12%) and 4 (8%) patients experienced grade 2 hand-foot syndrome and stomatitis, respectively (no episodes of grade 3). One patient developed grade 3 diarrhea requiring hospitalization for hydration. Six (12%) individuals required dose reductions. The median number of courses of liposomal doxorubicin administered on this protocol was 2 (range: 1-12). Four of 44 patients (9%) evaluable for response exhibited objective and subjective evidence of an antineoplastic effect of therapy. CONCLUSION: This modified liposomal doxorubicin regimen results in less toxicity (stomatitis, hand-foot syndrome) than the standard FDA-approved dose schedule. Definite, although limited, antineoplastic activity is observed in patients with well-defined platinum- and paclitaxel-refractory ovarian cancer.

Adult↗