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Biomedical subjects

Takamaru Ashikaga

Publications and source records attributed to Takamaru Ashikaga.

14 recordsLinked to original sources
PubMed2006

Detection of occult sentinel lymph node micrometastases by immunohistochemistry in breast cancer. An NSABP protocol B-32 quality assurance study.

BACKGROUND: Occult metastases, by definition, are not detected on initial examination. They may be present on slides but missed during screening or may be present in paraffin embedded tissue blocks and undetected without additional levels. Anticytokeratin immunohistochemistry (CK IHC) enhances detection of occult metastases, particularly micrometastases (> 0.2 mm but not larger than 2.0 mm) or isolated tumor cell clusters (< or = 0.2 mm). This study defines the rate at which pathologists miss metastases on CK IHC of sentinel lymph nodes (SLN). METHODS: CK IHC sections 0.5 and 1.0 mm from the original surface of SLN tissue blocks were screened by pathologists using standard bright field light microscopes (LM) and by supervised computer assisted cell detection (CACD). All blocks were from breast cancer patients, initially classified 'node negative' on review of routinely stained sections from the surface of each block. Cases missed by LM screening but detected by CACD defined false negative screens. RESULTS: Of 236 cases screened, LM detected 34 (14.4%; 95% CI: 9.6-20.2) cases and, in the 202 cases negative by LM, CACD detected an additional 30 (14.9%; 95% CI: 9.6-21.2%) cases with occult metastases. Occult metastases missed by LM screening ranged from 0.01 to 0.1 mm in greatest dimension. The probability of missing an occult metastasis < or = 0.02 mm; < or = 0.05 mm, and < or = 0.10 mm was 75%, 69.2%, and 61.2%, respectively. No occult metastases larger than 0.10 mm were missed by LM screening. CONCLUSIONS: Pathologists screening the CK IHC stained slides may frequently miss detecting metastases < 0.10 mm.

Axilla↗
PubMed2006

A study of low dose peginterferon alpha-2b with ribavirin for the initial treatment of chronic hepatitis C.

PURPOSE: A prospective randomized trial was undertaken to test the efficacy of low and standard doses of pegylated interferon alpha-2b in combination with ribavirin for the initial treatment of chronic hepatitis C. By nature of its design the study also provided data on response to therapy over a spectrum of doses of both pegylated interferon alpha-2b and ribavirin calculated on a body weight basis. SUBJECTS AND METHODS: Fifty micrograms of pegylated interferon alpha-2b or 100 microg for patients weighing<75 kg or 150 microg for patients>or=75 kg were administered weekly with 1000 mg ribavirin daily for 48 wk if serum hepatitis C virus (HCV) RNA was undetectable after the first 24 wk of therapy. RESULTS: Overall sustained viral response (SVR) was 45% for standard dose and 33% for low dose, p=0.02. For genotypes 2 and 3 SVR was 65% for standard dose, and 56% for low dose, p=0.51. For genotype 1 SVR was 38% for standard dose, and 24% for low dose, p=0.03. For genotype 1 patients whose doses exceeded the 1-2-5 threshold, that is >or=1.25 microg/kg body weight pegylated interferon alpha-2b weekly and >or=12.5 mg/kg body weight ribavirin daily, SVR was 51%. CONCLUSION: The results of this study underscore the importance of adequate dosing of ribavirin as well as pegylated interferons in achieving an SVR when treating genotype 1 chronic hepatitis C patients with combination therapy.

Adult↗
PubMed2005

Peginterferon alfa-2b and ribavirin for treatment-refractory chronic hepatitis C.

BACKGROUND/AIMS: Treatment regimens with pegylated interferons have yielded improved response rates, compared with conventional interferon-based regimens, for chronic hepatitis C. However, little is known about the utility of such regimens for individuals who failed to respond to prior conventional interferon-based treatment. METHODS: 182 patients who had previously failed to eliminate circulating hepatitis C virus 24 weeks after completion of a multi-week course of either interferon monotherapy or interferon in combination with ribavirin were treated with peginterferon alfa-2b weekly and ribavirin daily for 48 weeks. RESULTS: The sustained viral response, was 20% (23/116) in previous non-responders and 55% (36/66) in previous relapsers (P<0.001). In previous non-responders, the sustained viral response in those with viral genotype 1 was 17% (19/109) compared to 57% (4/7) in those with genotypes 2 and 3 (P=0.03). In previous relapsers, the sustained viral response in those with viral genotype 1 was 53% (26/49) compared to 59% (10/17) with genotypes 2 and 3 (P=0.78). CONCLUSIONS: The response to pegylated interferon and ribavirin in previous non-responders with genotypes 2 and 3 and in prior relapsers with chronic hepatitis C is comparable to overall sustained viral response rates seen in previously untreated patients.

Adult↗
PubMed2005

Texture analysis of post breast cancer lymphedema ultrasound images obtained using a portable device--a pilot study.

BACKGROUND: Lymphedema is a common complaint of post-breast cancer treatment. Some prior ultrasound imaging studies of lymphedema-affected upper extremities focused upon estimating the thickness of the dermis and subcutis areas. In contrast, however, the reliability and validity of texture features derived from ultrasound images obtained using a low-cost portable ultrasound device have not been reported. This study examined the reliability and validity of the first and second order quantitative image texture measures, average pixel intensity and entropy, and compared their site-specific correlations. METHODS AND RESULTS: A total of 10 ultrasound images of an ipsilateral affected elbow and the corresponding unaffected contralateral elbow were obtained using a portable ultrasound device. A Graphical User Interface software package for image analysis was developed and tested. Entropy and average pixel intensity at six adjacent regions of interest corresponding to the dermis and subcutis areas were calculated. Entropy had smaller coefficients of variation for each image compared to average pixel intensity with the intracluster correlation reliability coefficient for entropy being twice that of average pixel intensity. Both measures discriminated between the affected and unaffected sites (p < 0.001). However, the correlation between the two measures differed for affected (r = -0.060, p = 0.667) and unaffected (r = +0.595, p < 0.001) sites. CONCLUSIONS: The second order measure entropy is preferable to that of the first order average pixel intensity as a measure of image texture to characterize ultrasound images of extremity lymphedema.

Breast Neoplasms↗
PubMed2005

Prerandomization Surgical Training for the National Surgical Adjuvant Breast and Bowel Project (NSABP) B-32 trial: a randomized phase III clinical trial to compare sentinel node resection to conventional axillary dissection in clinically node-negative breast cancer.

OBJECTIVE: To train surgeons in a standardized technique of sentinel lymph node biopsy and to prepare them for the requirements of a prospective randomized surgical trial. SUMMARY BACKGROUND DATA: The NSABP B32 trial opened to accrual in May 1999. A significant component of this trial was a prerandomization training phase of surgeons performed by a group of core surgical trainers. The goals of this training phase were to expeditiously instruct surgeons in a standardized technique of sentinel lymph node biopsy and to educate those same surgeons in complete and accurate data collection and source documentation for the trial. METHODS: This study is a description of the training data collected in a prospective fashion for the training component for surgeon entry into the B32 trial, evaluating the effectiveness of the training program in regards to surgical outcomes and protocol compliance. RESULTS: Two hundred twenty-six registered surgeons underwent site visit training by a core surgical trainer and 187 completed training and were approved to randomize patients on the trial. The results of 815 training (nontrial) cases demonstrated a technical success rate for identifying sentinel nodes at 96.2% with a false negative rate of 6.7%. A protocol compliance analysis, which included the evaluation of 94 separate fields, showed mean protocol compliance of 98.6% for procedural fields, 95.5% for source documentation fields and 95.0% for data entry fields. CONCLUSIONS: This training and quality control program has resulted in a large number of surgeons capable of performing sentinel lymph node biopsy in a standardized fashion with a high degree of protocol compliance and pathologic accuracy. This will ensure optimal results for procedures performed on the randomized phase of the trial.

Axilla↗
PubMed2005

Measuring the nursing workforce: clarifying the definitions.

Numerous articles have addressed the causes and implications of the current nursing shortage. Little has been published, however, about how to measure the nursing workforce. This article presents (1) a review of definitions for common workforce indicators such as vacancy and turnoverrates and the relationship between these indicators and the need for nurses,(2) a review of the calculation of vacancy and turnoverrates in several statewide and national surveys, and (3) the results from the development and pilot test of a health care workforce survey for use in Vermont. The review indicates that in practice, no standard method is used despite attempts to standardize the calculation of vacancy and turnover rates. The Vermont pilot study results demonstrate that a richer profile of the health workforce can be obtained by using both standard workforce measures and more subjective questions to assess a statewide need for nurses.

Data Collection↗
PubMed2005

Attitudes and beliefs of primary care physicians regarding prostate and colorectal cancer screening in a rural state.

BACKGROUND: Screening for prostate cancer (PC) is paradoxically more prevalent than for colorectal cancer (CRC). METHODS: Primary care physicians (PCPs) in Vermont were surveyed concerning PC and CRC screening. RESULTS: Aggressive screening for PC and CRC remains widespread. PCPs reported that they controlled screening decisions for the majority of their patients. A belief that evidence favored PC screening for no patients was associated with less aggressive screening for PC as well as CRC. CONCLUSIONS: Aggressive screening behavior is frequent, physician-driven and correlates with physician beliefs. Better education of PCPs is the key to changing screening behavior.

Adult↗
PubMed2004

Influence of breast cancer histology on the relationship between ultrasound and pathology tumor size measurements.

Establishing an accurate primary invasive breast cancer size is crucial for patient management. Although ultrasonographic measurement is reported to correlate reliably with the gold standard pathology measurement, few authors have examined the influence of histologic subtype on ultrasound measurement. The common subtypes of invasive breast carcinoma, ductal and lobular, have different growth patterns, which may influence the ability of ultrasound to predict pathologic size. For this analysis, ultrasound and pathology reports were retrospectively reviewed for 204 women with 210 invasive breast cancers, including 129 ductal, 41 lobular, and 40 mixed pattern ductal and lobular carcinomas. For each tumor, the largest pathology and ultrasound dimensions were compared using Pearson's correlations, linear regression, paired t-tests and Wilcoxon signed ranks tests, stratified by histologic subtype. The Hodges-Lehmann approach was used to obtain 95% confidence intervals (CI) for median difference of the sizes. Ultrasonography consistently underestimated pathologic tumor size; the overall median difference was 3.5 mm (CI: 2.5-4.0 mm) and for subtypes: 2.5 mm (CI: 1.5-3.5 mm) for ductal pattern; 3.0 mm (CI: 1.5-4.5 mm) for mixed pattern; and in contrast, 7.5 mm (CI: 5.0-13.5 mm) for lobular pattern tumors. Significant correlations of similar magnitude, were observed between size measurements for ductal, lobular, and mixed subtypes (r=0.816, 0.811 and 0.672, respectively; all P<0.001); however, linear regression models differed between subtypes. Although practical and widely available, ultrasonography tends to underestimate pathologic tumor size. The size difference may be large for lobular carcinomas, potentially influencing stage; differences are less pronounced for ductal and mixed subtypes. Pathologic tumor size can be estimated from the ultrasonographic measurement, particularly if the histologic tumor subtype is known. The results of this study underscore the continued benefit of pretreatment tumor histology.

Breast Neoplasms↗
PubMed2004

Attitudes, perceived norms, and intentions: a needs assessment study of the influenza immunization intentions of elderly citizens in Vermont.

CONTEXT: Influenza and pneumonia rank among the 5 leading causes of death among persons aged 65 and over. Although immunization has been demonstrated to prevent influenza or reduce its incidence and associated complications among the elderly, it has been largely underutilized. PURPOSE: This study examined the association of attitudes, perceived norms, and intention to obtain influenza immunization among community-dwelling rural elderly. The goal was to design an effective intervention program to increase the rate of flu immunization among the rural elderly. METHODS: In spring 2000, random-digit dialing selected 1,239 households in 2 rural Vermont counties. Telephone interviews were conducted with 799 persons aged 60 or older, resulting in a response rate of 65%. FINDINGS: Factor analyses revealed 2 dimensions underlying attitudes and perceived norms. Subsequent regression analyses confirmed that 1 attitude construct--perceived benefits--and both normative indices were significant predictors of immunization intention, explaining 45% of its variation. CONCLUSIONS: An intervention program targeting rural elderly should emphasize the benefits and perceived side effects of immunization. The program should publicize that most elderly believe that the advantages of influenza immunization outweigh the disadvantages. These findings will inform an intervention program designed to increase immunization coverage among rural seniors in Vermont.

Aged↗
PubMed2004

Primary central nervous system posttransplant lymphoproliferative disorders.

Posttransplant lymphoproliferative disorders (PTLDs) represent a spectrum ranging from Epstein-Barr virus (EBV)-driven polyclonal lymphoid proliferations to EBV+ or EBV- malignant lymphomas. Central nervous system (CNS) PTLDs have not been characterized fully. We reviewed the clinical, radiologic, and pathologic features of 12 primary CNS PTLDs to define them more precisely. Patients included 10 males and 2 females (median age, 43.4 years) who were recipients of kidney (n = 5), liver (n = 2), heart (n = 2), peripheral blood stem cells (n = 2), or bone marrow (n = 1). All received immunosuppressive therapy. CNS symptoms developed 3 to 131 months (mean, 31 months) after transplantation. By neuroimaging, most showed multiple (3 to 9) intra-axial, contrast-enhancing lesions. Histologic sections showed marked expansion of perivascular spaces by large, cytologically malignant lymphoid cells that were CD45+, CD20+, EBV+ and showed light chain restriction or immunoglobulin gene rearrangement. In distinction to PTLDs in other organ systems, CNS PTLDs were uniformly high-grade lymphomas that fulfilled the World Health Organization criteria for monomorphic PTLDs. Extremely short survival periods were noted for each CNS PTLD that followed peripheral blood stem cell transplantation. Survival of others with CNS PTLD varied; some lived more than 2 years.

Adult↗
PubMed2002

Factors influencing intention to obtain a genetic test for colon cancer risk: a population-based study.

BACKGROUND: The availability of genetic testing for cancer risk has prompted an examination of the intention of the general public to undergo testing. This study expands a previous psychosocial model of factors influencing intention to undergo genetic testing for cancer in general to the context of colon cancer. METHODS: A sample of 1,836 adult residents of Vermont, New Hampshire, and Maine were interviewed via telephone. The survey instrument included measures derived from the Health Belief Model and additional psychosocial measures adapted from the literature. Structural Equation Modeling techniques were used to examine factors associated with the likelihood to undergo genetic testing. RESULTS: Perceived barriers and benefits of testing, and perceived susceptibility to colon cancer had direct associations with likelihood. Optimism and pessimism had both direct and indirect effects. Age, socioeconomic status, family history, and awareness of genetic testing had indirect effects, and acted through the other factors. The model explained 22% of the variance in likelihood. CONCLUSIONS: Perceived barriers, benefits, susceptibility, optimism, and pessimism directly influenced likelihood, and may also mediate the effect of background factors examined in this study. These findings suggest effective educational strategies to improve decision-making concerning genetic testing for colon cancer risk in the general population.

Adult↗
PubMed2002

Knowledge about preventing and managing lymphedema: a survey of recently diagnosed and treated breast cancer patients.

Physical therapists, books and oncologist's staff were the most frequently cited sources of lymphedema prevention and management information in a telephone survey of 148 recently treated breast cancer patients. Awareness, current practice and intention to practice 13 recommended prevention behaviors were low, and variations in these indices and in information sources were observed between those reporting any swelling and those who did not. Citing radiation oncologists as an information source reflected significantly higher levels of awareness, practice and intention as compared to not citing them. Also, citing oncologists reflected lower scores on the three indices as compared to not citing them. The results suggest that lymphedema prevention and management information is not getting to breast cancer survivors in a timely fashion and underscore the urgent need to develop and implement appropriate educational strategies. Additionally, research into factors that could motivate survivors to practice the recommended behaviors is warranted.

Analysis of Variance↗
PubMedDate not supplied

Swelling, numbness, pain, and their relationship to arm function among breast cancer survivors: a disablement process model perspective.

The disablement process model proposed by Nagi in 1965 and subsequently expanded by Verbrugge and Jette was used heuristically to study the relationships among morbidities and arm/shoulder function limitations that breast cancer survivors experience in the period following treatment. A telephone survey was administered to 148 patients (67%) from among 222 breast cancer survivors who had undergone surgery in 1997 and 1998. Sixty-three percent of respondents reported experiencing some numbness, while 35% noticed swelling. Between 13% and 15% reported moderate to severe pain. Similar proportions said the occurrence of pain ranged from intermittent to constant. Between 1% and 4% reported problems with shoulder abduction and flexion and a decrease in arm strength and daily use of the arm. Swellings in the torso and arm tended to cluster into two different factors. Numbness followed a similar pattern. Apart from numbness in the arm, all the other factors had strong significant associations with one another. In multiple regression analyses, current pain intensity and swelling in the arm were independently related to current functional status of the arm/shoulder. The results suggest that it may be feasible to use patients' self-reports to develop a simple lymphedema-specific tool to monitor the functional status of women living with or at risk for lymphedema. Such a tool, if properly designed and implemented, would allow for the timely introduction of lymphedema or pain management strategies to improve arm function and ultimately the quality of life of breast cancer survivors.

Activities of Daily Living↗