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Biomedical subjects

D M Harper

Publications and source records attributed to D M Harper.

At least 19 recordsLinked to original sources

Using stable isotope analyses to identify allochthonous inputs to Lake Naivasha mediated via the hippopotamus gut.

The hippopotamus grazes nocturnally on land and resides in water during the day. Much of the ingested material must therefore be defecated directly into the aquatic system and can thus be considered an allochthonous resource available to aquatic consumers. The utility of stable isotope analyses of carbon and nitrogen to distinguish hippo faecal matter from other potential basal resources was tested at Lake Naivasha, Kenya. Hippopotami proved faithful to a short grass diet although supplementary grazing of aquatic macrophytes was observed. The typical isotopic ratios of C4 grasses ingested were not altered substantially by gut processes, and were clearly distinct from algal and aquatic macrophyte isotopic ratios. However, marginal plants such as Cyperus papyrus exhibit C4 ratios, and so the technique is suitable only for use in localities where 'contamination' from such sources is negligible.

Animals↗

T-cell differentiation of human and non-human primate CD34+ hematopoietic progenitor cells using porcine thymic stroma.

Transplantation of swine thymic tissue has been proposed as an approach to reconstitute the immune system of HIV-infected individuals. This is an attractive strategy because miniature swine are readily available as donors and porcine tissue is resistant to infection with HIV-1. Demonstration that porcine thymus tissue supports primate T-cell differentiation is critical to the ultimate utility of this approach. Using a thymic stroma culture system we have previously described [Rosenzweig M, Marks DF, Zhu H et al. In vitro T lymphopoiesis of human and rhesus CD34+ progenitor cells. Blood 1996; 87: 4040], we demonstrate that porcine thymus tissue is able to promote the in vitro T-lymphocyte differentiation of both human and non-human primate hematopoietic progenitor cells. CD34+ hematopoietic progenitors differentiated into both double positive (CD4+CD8+) and single positive thymocytes expressing CD4 or CD8 alone. A polyclonal T-cell repertoire was evident. In addition, the T cells responded appropriately to mitogen and were permissive to infection with simian immunodeficiency virus (SIV). These data demonstrate the ability of porcine thymus to support T-cell differentiation of both human and non-human hematopoietic progenitor cells and support in vivo studies of transplantation of swine thymic tissue as a strategy for immune reconstitution in AIDS.

Animals↗

Analysis of acetic acid-induced whitening of high-grade squamous intraepithelial lesions.

Immature and dysplastic cervical squamous epithelium whitens after the application of acetic acid during a colposcopic examination. The whitening process occurs visually over several minutes and subjectively discriminates between dysplastic and normal tissue. In this work, examples of the acetowhitening process are detailed in three ways: the color-imaged colposcopic appearance of the acetowhitening of high-grade cervical intraepithelial neoplasia (CIN 2/3), the kinetics of these reflectance patterns transformed to reduce noise in the signal, and a self-normalized green to red ratio measurement of the kinetics of these reflectance patterns. A total of six patients with biopsy confirmed CIN 2/3 were examined to obtain a set of timed images tracking the acetowhitening and the whitening-decay process over the course of 5-10 min. Regions of normal mature squamous epithelium within the same patients were also followed as an internal control. We determined that the temporal change over a 10 min time period in the ratio of green to red light intensities, taken from the respective color channels of the CCD, provides a reliable measure to clearly distinguish CIN 2/3 from normal cervical epithelium. This imaging and data normalization procedure may be applied to cervical lesions of different grades, to determine if a quantitative estimate provides predictive value during the colposcopic diagnosis.

Acetic Acid↗

Cost-effectiveness of the conventional papanicolaou test with a new adjunct to cytological screening for squamous cell carcinoma of the uterine cervix and its precursors.

OBJECTIVE: To estimate costs and outcomes of conventional annual Papanicolaou (Pap) test screening compared with biennial Pap test plus speculoscopy (PPS) screening for cervical neoplasms. DESIGN: A Markov model compared cost-effectiveness and outcomes of annual Pap tests with biennial PPS. The model includes direct costs of screening, diagnostic testing, and treatment for squamous intraepitheial lesions and invasive cancers; indirect costs (eg, lost productivity because of cervical cancer); and newer management practices, including human papillomavirus DNA testing. PATIENTS: Women aged 18 to 64 years. INTERVENTION: Screening for cervical neoplasms with either annual Pap smear test or biennial PPS. MAIN OUTCOME MEASURE: Marginal cost per life-year gained. RESULTS: The probability of women having squamous intraepithelial lesions, cervical cancer, or death from cervical cancer was lower among women undergoing PPS biennially. A total of 12 additional days of life per woman was gained with biennial PPS during the 47-year model period. Total average cumulative direct medical costs per patient were $1419 for biennial PPS compared with $1489 for annual Pap tests. Total costs, including direct medical costs and indirect costs, were $2185 for PPS compared with $3179 for Pap tests alone. Increased savings and patient outcomes were observed in high-risk populations. CONCLUSION: Our simulations indicate that biennial screening with PPS is expected to provide cost savings for women older than 18 years compared with annual Pap test screening, especially for those in high-risk populations.

Adult↗

Self-reported desire to improve colposcopic impressions.

BACKGROUND: Women who participate in cervical cancer screening programs must have access to high quality colposcopy services when their cytology test are abnormal. The purpose of this project is to evaluate colposcopic services currently available in New Hampshire and whether colposcopy providers are willing to network to maintain and improve their colposcopic pattern recognition skills in order to improve their colposcopic correlations. METHODS: A survey was mailed to 1314 providers throughout New Hampshire. The survey ascertained the extent of current colposcopic services in New Hampshire through practitioner and practice demographics, the cervical procedures performed, the self-reported colposcopy skill level, and the self-reported quality of past colposcopic education. It also measured interest in networking with others to improve their colposcopic pattern recognition skills. RESULTS: The survey response rate was 62%. 145 of the 810 respondents (18%) are currently performing colposcopies, indicating a statewide potential colposcopy accommodation rate of 3.5 to 7 women per month per colposcopist. 57% of the physician assistants, 59% of the family physicians, 75% of the gynecologists and 100% of the nurse practitioners were interested in enhancing their colposcopic pattern recognition skills by networking through quarterly meetings. CONCLUSIONS: The crude accommodation rate for colposcopy appears sufficient for the women of New Hampshire although the geographic distribution of the colposcopists is unknown. A majority of the colposcopists were interested in networking to improve their colposcopic pattern recognition skills, which could improve patient care.

Clinical Competence↗

The technical performance and clinical feasibility of telecolposcopy.

BACKGROUND: The purpose of our study was to demonstrate the technical performance and clinical feasibility of a telecolposcopic system through assessment of image transmission veracity, ease of office system implementation, and the patient's acceptance of the electronic image transmission. METHODS: We used a telecolposcopic system incorporating a custom software package that integrated patient history, current gynecologic status, epidemiologic risk factors, and colposcopic images for local medical documentation and transmission. Satisfaction questionnaires were developed to measure ease of implementation at the remote sites and the patients' acceptance of telecolposcopy. RESULTS: Seventy-nine women participated in our trial. From 3 to 20 images were captured for each woman, documenting cervical squamous intraepithelial lesions and vaginal and vulvar diseases. All images were received without distortions in color, size, or orientation. With complete visualization of the squamocolumnar junction there was an 86% agreement between the remote and review sites (kappa=.533, P=.019). The interobserver agreement for colposcopic impressions was 86% (kappa=.684, P <.001), and for colposcopic impressions with histology within one level of disease severity, 86% (kappa=.78, P <.001). Colposcopists' and patients' satisfaction with telecolposcopy was excellent. More than 95% of the women stated that they would rather have their colposcopy locally with electronic transmission if an experienced colposcopist were more than 25 miles away. CONCLUSIONS: The telecolposcopic system described in our study is technically feasible, can be implemented in an office system with limited technical support, and is preferred by women who have to travel many miles to receive referral health care.

Adolescent↗

The natural history of cervical cryosurgical healing. The minimal effect of debridement of the cervical eschar [see comment].

BACKGROUND: Cryosurgery is a favored treatment method for cervical intraepithelial neoplasia (CIN) among family physicians, in part because it is inexpensive and requires the least technical training and skill. Although cervical cryosurgery has been used for more than 30 years, the natural history of the postprocedure process has never been described. The primary purpose of our study was to describe the natural history of the healing process after cervical cryosurgery. A secondary purpose was to determine the effect of mechanical debridement of the cervical eschar on the symptoms of healing. METHODS: We conducted a prospective multicentered trial in which women who had a histologic ally documented CIN lesion underwent cervical cryosurgery. Forty-six women were randomized to undergo eschar debridement at 48 hours after cryosurgey, and 38 women received standard care. All women were followed up and given preweighed sanitary pads for hydrorrhea (watery discharge) collection and a diary to record the severity and number of days of odor, pain, cramping, and hydrorrhea that were experienced. RESULTS: The average total amount of hydrorrhea or discharge was 288 g, which required using an average of 41 sanitary pads during a period of 12.4 days. The duration of odor was 8.9 days, and the pain and cramping experienced after cryosurgery lasted 4.7 days. Women who were obese had greater hydrorrhea and pad usage than nonobese women. Debridement of the cervical eschar did not significantly change the signs and symptoms of healing after cryosurgery. CONCLUSIONS: There are significant symptoms patients experience after cryosurgery that are not ameliorated by debridement. The expectations of the cryosurgical healing process should be disclosed to women before the procedure.

Adult↗

Healing experiences after cervical cryosurgery.

BACKGROUND: Treatment for cervical intraepithelial neoplasia with cryosurgery is uncomfortable for many women. The subsequent healing process is also thought to bring discomfort. The purpose of our study was to describe women's experiences after cryosurgery, and how obesity, age, and gravidity affected, the healing process. METHODS: We developed a survey from focus group results to measure the unpleasantness of hydrorrhea (watery discharge) from cryosurgery, the pad protection required, and the odor associated with the hydrorrhea. The cryosurgical experiences were compared with normal menses for the use and frequency of pad protection, medications used, and any activity restrictions. RESULTS: Cryosurgical experiences were unpleasant for 78.3% of the women because of the pain and cramping of the procedure and the resulting hydrorrhea, odor, and necessity of wearing pads for protection. These experiences after cryosurgery caused 38.6% to restrict their activities and 67.1% to take medications, a significantly greater proportion than the 16.9% whose activities were restricted normal menses and the 26.8% who took medications for normal menses (P=-.004, P <.001, respectively). In addition to these experiences, obese, multigravid, and older women were more bothered by the duration of wearing pads than their counterparts (P=.0246, =.0061, and P=.0159, respectively). CONCLUSIONS: Our study showed that the cryosurgical healing process was not pleasant, and was least tolerable for obese, multigravid, and older women. As many as 50% of women undergoing cryosurgery will perceive the hydrorrhea, its odor, and the wearing of pads to be worse than normal menses, especially if their menses are usually light.

Adolescent↗

The benefits of group music at the 1996 music weekend for women with cancer.

BACKGROUND: Music therapy has been proven to benefit cancer patients physically and emotionally. The Music Weekend for Women with Cancer was developed as a novel opportunity for participants to experience the healing powers of music amidst others who had a shared understanding of their illness. MATERIALS AND METHODS: Fourteen female mixed cancer patients, three spouses, and one daughter attended the weekend from Friday evening through Sunday afternoon. Workshops and events centered on the use of music as a vehicle for expression of emotions, reflection, relaxation, communication, and enjoyment. Questionnaires were collected before the weekend to describe our population as well as three months after the weekend to assess any changes in their utilization of music and mood state. RESULTS: Although insufficiency of post-weekend data limited the potential for assessing the effects of the weekend on the participants' utilization of music and mood state, the extremely positive evaluations supported the role music can play in helping patients and families explore their reactions to cancer. CONCLUSIONS: Events such as this answer the call in the literature for more opportunities to use music and the arts in cancer education. The authors hope this weekend will serve as a prototype for future events that aim to offer the benefits of music.

Attitude to Health↗

Is it cost-effective to use a mucosal or paracervical block to relieve the pain and cramping from cryosurgery? A decision model.

BACKGROUND: Cryosurgery is an effective treatment for cervical intraepithelial neoplasia, but it often causes pain and cramping. Both paracervical and mucosal blocks have been shown to provide relief from the pain and cramping associated with cryosurgery. The purpose of this article is to recommend the use of mucosal block, paracervical block, or no block on the basis of which procedure minimizes the costs of averting the pain and cramping that a woman experiences during cryosurgery. METHODS: A decision model was constructed encompassing the options (mucosal block, paracervical block, or no block) that a physician has when performing cryosurgery. The 4 possible outcomes for a patient undergoing cryosurgery were diagrammed as: (1) no pain and no cramping; (2) only cramping; (3) only pain; and (4) both pain and cramping. Each of these outcomes was measured on a 200-mm horizontal visual analog scale. Costs were derived for cryosurgery from the office perspective. Sensitivity analyses were conducted to test the robustness of the analysis. RESULTS: The base case analysis showed that the lowest cost per pain and cramping averted was for women who had a mucosal block before cryosurgery ($153.87), compared with women with a paracervical block ($183.24) and women with no block ($218.83). CONCLUSIONS: A mucosal block is the most cost-effective method to avert the pain and cramping from cryosurgery in women who have taken a nonsteroidal anti-inflammatory drug before the procedure.

Anesthesia, Obstetrical↗

Collection devices for human papillomavirus.

BACKGROUND: Human papillomavirus (HPV) testing has relied to date on samples collected by experienced health professionals. Self-administered testing devices could allow HPV testing to occur in large-scale epidemiologic studies of primary care screening populations. The purpose of this study is to determine whether a self-collection device for cervicovaginal HPV infection could be developed. METHODS: A prospective randomized trial of a consecutive sampling of 93 women, 18 years or older, receiving routine cervical cancer screening and colposcopy in the urban gynecologic clinics in Philadelphia, Pennsylvania, were randomized into 2 arms. Women in arm 1 used a self-administered tampon before the physician-directed swabs of the cervix; in arm 2, women underwent the physician-directed swab testing before using the self-administered tampon. The concordance of HPV DNA positivity between sampling methods detected by a Hybrid Capture HPV tube test for both low- and high-risk types of HPV was the main outcome measure. RESULTS: The concordance rate (ie, women whose cultures were classified as negative on both tests or positive on both tests) for arms 1 and 2 were similar: 78.3% and 80.9%, respectively. CONCLUSIONS: The tampon was equivalent to the physician-directed swab in HPV detection and suggests its feasibility in long-term primary care studies of screening populations.

Adolescent↗

Increased rates of CD4(+) and CD8(+) T lymphocyte turnover in simian immunodeficiency virus-infected macaques.

Defining the rate at which T cells turn over has important implications for our understanding of T lymphocyte homeostasis and AIDS pathogenesis, yet little information on T cell turnover is available. We used the nucleoside analogue bromodeoxyuridine (BrdUrd) in combination with five-color flow cytometric analysis to evaluate T lymphocyte turnover rates in normal and simian immunodeficiency virus (SIV)-infected rhesus macaques. T cells in normal animals turned over at relatively rapid rates, with memory cells turning over more quickly than naive cells. In SIV-infected animals, the labeling and elimination rates of both CD4(+) and CD8(+) BrdUrd-labeled cells were increased by 2- to 3-fold as compared with normal controls. In normal and SIV-infected animals, the rates of CD4(+) T cell BrdUrd-labeling and decay were closely correlated with those of CD8(+) T cells. The elimination rate of BrdUrd-labeled cells was accelerated in both naive and memory T lymphocytes in SIV-infected animals. Our results provide direct evidence for increased rates of both CD4(+) and CD8(+) T cell turnover in AIDS virus infection and have important implications for our understanding of T cell homeostasis and the mechanisms responsible for CD4(+) T cell depletion in AIDS.

Animals↗

Leukocytes in the cervix: a quantitative evaluation of cervicitis.

OBJECTIVE: To quantify the numbers of leukocytes in the normal cervix and relate these numbers to the diagnosis of cervicitis. METHODS: Isolated cell suspensions were prepared from cervical tissue recovered at hysterectomy from 37 women who had no obvious cervical disease. The percentages of CD45+ cells (leukocytes) in these preparations were determined using immunofluorescence-based flow cytometric analysis. These percentages were compared with the pathologist's assessment of cervicitis. RESULTS: Leukocytes were present in all cervical samples tested. For endocervical samples, the mean (+/- standard error of the mean [SEM]) percentage of CD45+ cells was 12.4 +/- 1.9% of cells in patients with a diagnosis of cervicitis (n = 16) and 9.1 +/- 1.1% in patients without cervicitis (n = 17). For ectocervical samples, the mean (+/- SEM) percentage was 14.8 +/- 3.0% in those with cervicitis (n = 16) and 9.5 +/- 1.6% in those without cervicitis (n = 19). The differences between samples from patients with cervicitis and those without cervicitis were not statistically significant at the .05 level. Intra- and interassay variabilities were 5.7 +/- 1.2% and 7.3 +/- 1.6%, respectively. CONCLUSION: Our study demonstrates there is a resident population of leukocytes in the cervix. Leukocyte number did not relate clearly and consistently to the diagnosis of cervicitis made by the pathologist. We suggest that the resident population of leukocytes, in the absence of other indicators of infection, may confuse determinations of cervicitis.

Cell Count↗

Cervical mucosal block effectively reduces the pain and cramping from cryosurgery.

BACKGROUND: Cryosurgery is an effective treatment for squamous intraepithelial lesions, but causes pain and cramping regardless of the particular method of cryosurgery used. The purpose of our study was to determine how effective a four-quadrant cervical mucosal block is in reducing the pain and cramping of cryosurgery. METHODS: Of the 112 women presenting for cryosurgery at the teaching clinics of the University of Missouri-Kansas City School of Medicine at Truman Medical Center-East between September 1995 and September 1996, 87 completed the study. The first 39 women were given the standard treatment of no block with the cryosurgery procedure. The subsequent 48 women were given a four-quadrant submucosal block of 1% lidocaine with 1:100,000 epinephrine 5 minutes before cryosurgery. The intensity of pain and cramping of each part of the procedure was measured on 100-mm visual analog scales. RESULTS: The pain and cramping of cryosurgery were significantly reduced (P < .05) with the mucosal block for all measured parts of the cryosurgery procedure, including pain of the first freeze (39 mm vs 12 mm), cramping of the first freeze (49 mm vs 13 mm), pain of the second freeze (24 mm vs 12 mm), cramping of the second freeze (32 mm vs 18 mm), pain of the total composite procedure (44 mm vs 28 mm), and cramping of the total composite procedure (51 mm vs 21 mm). CONCLUSIONS: A four-quadrant mucosal block effectively reduces the amount of pain and cramping associated with cryosurgery.

Adult↗