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Biomedical subjects

C E Stevens

Publications and source records attributed to C E Stevens.

At least 19 recordsLinked to original sources
PubMed2001

Hematopoietic engraftment and survival in adult recipients of umbilical-cord blood from unrelated donors.

BACKGROUND: Umbilical-cord blood from unrelated donors who are not HLA-identical with the recipients can restore hematopoiesis after myeloablative therapy in children. We studied the use of transplantation of umbilical-cord blood to restore hematopoiesis in adults. METHODS: Sixty-eight adults with life-threatening hematologic disorders received intensive chemotherapy or total-body irradiation and then transplants of HLA-mismatched umbilical-cord blood. We evaluated the outcomes in terms of hematologic reconstitution, the occurrence of acute and chronic graft-versus-host disease (GVHD), relapses, and event-free survival. RESULTS: Of the 68 patients, 48 (71 percent) received grafts of umbilical-cord blood that were mismatched for two or more HLA antigens. Of the 60 patients who survived 28 days or more after transplantation, 55 had neutrophil engraftment at a median of 27 days (range, 13 to 59). The estimated probability of neutrophil recovery in the 68 patients was 0.90 (95 percent confidence interval, 0.85 to 1.0). The presence of a relatively high number of nucleated cells in the umbilical-cord blood before it was frozen was associated with faster recovery of neutrophils. Severe acute GVHD (of grade III or IV) occurred in 11 of 55 patients who could be evaluated within the first 100 days after transplantation. Chronic GVHD developed in 12 of 33 patients who survived for more than 100 days after transplantation. The median follow-up for survivors was 22 months (range, 11 to 51). Of the 68 patients, 19 were alive and 18 of these (26 percent) were disease-free 40 months after transplantation. The presence of a high number of CD34+ cells in the graft was associated with improved event-free survival (P=0.05). CONCLUSIONS: Umbilical-cord blood from unrelated donors can restore hematopoiesis in adults who receive myeloablative therapy and is associated with acceptable rates of severe acute and chronic GVHD.

Acute Disease↗
PubMed2001

Evaluation of a low-dose nonoxynol-9 gel for the prevention of sexually transmitted diseases: a randomized clinical trial.

BACKGROUND: Low-dose nonoxynol-9 products have a potential advantage of reduced toxicity. However, little is known about their efficacy in reducing the incidence of sexually transmitted diseases (STDs). GOAL: To determine the effect that an intravaginal gel containing 52.5 mg of nonoxynol-9 has on the acquisition of STDs in a cohort of HIV-1-seronegative female sex workers in Mombasa, Kenya. STUDY DESIGN: A randomized double-blind placebo controlled trial was performed. RESULTS: In this study, 139 women were randomized to the nonoxynol-9 group and 139 to the placebo group. No significant differences were found between the two study groups in terms of safety outcomes and reported symptoms, except for a lower incidence of vaginal erythema in the nonoxynol-9 group. There was a significantly higher incidence of gonorrhea in the nonoxynol-9 group than in the placebo group. No significant differences were observed between the groups for acquisition of Candida, trichomonas, bacterial vaginosis, C trachomatis, syphilis, or HIV-1, although the statistical power to detect differences for some of these STDs was limited. CONCLUSIONS: In this randomized placebo-controlled trial of a low-dose nonoxynol-9 gel, a significantly higher incidence of gonorrhea was found in the nonoxynol-9 group, but no significant differences between the groups were found for Candida, trichomonas, bacterial vaginosis, C trachomatis, syphilis, or HIV-1.

Administration, Intravaginal↗
PubMed2000

Cell dose and speed of engraftment in placental/umbilical cord blood transplantation: graft progenitor cell content is a better predictor than nucleated cell quantity.

There is evidence that the total cellular content of placental cord blood (PCB) grafts is related to the speed of engraftment, though the total nucleated cell (TNC) dose is not a precise predictor of the time of neutrophil or platelet engraftment. It is important to understand the reasons for the quantitative association and to improve the criteria for selecting PCB grafts by using indices more precisely predictive of engraftment. The posttransplant course of 204 patients who received grafts evaluated for hematopoietic colony-forming cell (CFC) content among 562 patients reported previously were analyzed using univariate and multivariate life-table techniques to determine whether CFC doses predicted hematopoietic engraftment speed and risk for transplant-related events more accurately than the TNC dose. Actuarial times to neutrophil and platelet engraftment were shown to correlate with the cell dose, whether estimated as TNC or CFC per kilogram of recipient's weight. CFC association with the day of recovery of 500 neutrophils/microL, measured as the coefficient of correlation, was stronger than that of the TNC (R = -0.46 and -0.413, respectively). In multivariate tests of speed of platelet and neutrophil engraftment and of probability of posttransplantation events, the inclusion of CFC in the model displaced the significance of the high relative risks associated with TNC. The CFC content of PCB units is associated more rigorously with the major covariates of posttransplantation survival than is the TNC and is, therefore, a better index of the hematopoietic content of PCB grafts. (Blood. 2000;96:2717-2722)

Adolescent↗
PubMed2000

Graft-versus-leukemia-induced complete remission following unrelated umbilical cord blood transplantation for acute leukemia.

A 15-year-old female received an unrelated three of six HLA antigen matched umbilical cord blood (UCB) transplant for refractory, relapsed T-cell ALL. Conditioning consisted of TBI, melphalan, and anti-thymocyte globulin (ATG), with cyclosporin A (CsA) and solumedrol for GVHD prophylaxis. She engrafted and a day 34 bone marrow aspirate showed 100% donor cells and no evidence of leukemia. The post-transplant course was complicated by mild grade I acute GVHD involving skin, and limited chronic GVHD of the gut which resolved with the addition of 1 mg/kg/day of steroids to her CsA prophylaxis. One hundred and ninety days after transplantation the patient developed pancytopenia and was subsequently found to have a leukemic relapse. Immunosuppression was discontinued and she was started on G-CSF and erythropoietin. Moderate skin and gut GVHD developed which was treated with both topical and low-dose oral steroids. Over the next few weeks she became transfusion independent and a follow-up bone marrow aspirate showed complete remission. She continued in complete remission for 4 months, at which time localized leukemic relapse was found in a soft tissue breast mass in spite of continued bone marrow remission. While the patient ultimately died of progressive disease, this case demonstrates that mismatched UCB in conjunction with G-CSF is capable of generating a GVL effect that can induce a complete remission.

Adolescent↗
PubMed2000

Placental blood for bone marrow replacement: the New York Blood Center's program and clinical results.

BACKGROUND AND OBJECTIVES: Placental/umbilical cord blood (PCB) has been used for allogeneic bone marrow replacement since 1988. The Placental Blood Program of the New York Blood Center has developed techniques for collecting, testing, freezing and searching units on behalf of unrelated patients in need of hematopoietic stem cell replacement since 1993 and provided analysis of the outcomes of these transplants identified variables associated with clinical outcomes. In this review, after considering practical and conceptual aspects of the technology, we update information on the clinical outcomes of these transplants. MATERIALS AND METHODS: All 861 patients transplanted through 1999 with PCB from our Program are included in this report. Two thirds were diagnosed with leukaemia or lymphoma, 25% with inherited conditions and 7% with acquired diseases. Outcome data were provided by the respective Transplant Center and analyses included both univariate and multivariate regression tests and actuarial (Kaplan-Meier) techniques. RESULTS: Engraftment was achieved by over 90% of recipients (Kaplan-Meier estimate). Multivariate analysis confirmed the influence of cell dose, HLA matching, disease diagnosis and transplant center location (US vs. foreign). Patient age and HLA match grade independently affected the frequency and severity of acute graft vs. host disease. Leukaemic relapse was associated with the stage of disease at transplantation and the prior existence of acute graft vs. host disease. The probability of transplant-related events was independently associated with disease diagnosis, cell dose, number of HLA mismatches and transplant center, while the cell dose failed to associate significantly with the relative risk of reaching this endpoint in the subset of patients who achieved engraftment. Overall, event-free survival rates at one year post-transplant were 49 and 30%, respectively for genetic disease and haematologic malignancies and 35% for patients with acquired diseases, respectively. CONCLUSIONS: These results confirm and extend earlier data, particularly establishing the significant association of transplant success with histocompatibility matching grades, and indicatng the urgency of improving the transplant match levels.

Adolescent↗
PubMed1999

Long-term survival after infection with human immunodeficiency virus type 1 (HIV-1) among homosexual men in hepatitis B vaccine trial cohorts in Amsterdam, New York City, and San Francisco, 1978-1995.

Information on long-term survival after infection with human immunodeficiency virus type 1 (HIV-1) is limited. In hepatitis B vaccine trials in Amsterdam, New York City, and San Francisco, 362 gay men were followed up to 18 years (1978-1995). The median survival time from seroconversion was 12.1 years (95% confidence interval: 11.4, 12.9). The annual risk of dying increased at a constant rate until 8 years after seroconversion and then leveled off, suggesting a group that is relatively resistant to progression. These data provide a picture of the natural history of HIV-1 infection, especially in the era prior to widespread use of highly effective treatments.

Adult↗
PubMed1999

A matched prospective study of human immunodeficiency virus serostatus, human papillomavirus DNA, and cervical lesions detected by cytology and colposcopy.

OBJECTIVE: To compare the prevalence and type of human papillomavirus (HPV) infections in the genital tract of human-immunodeficiency-virus- (HIV) seropositive and -seronegative women matched for cytology and to examine prospectively the relationship of HPV DNA, colposcopic findings and cervical squamous intraepithelial lesions (SIL) in these matched seropositive and seronegative cohorts. METHODS: A matched prospective study of HIV-seropositive and -seronegative women undergoing cytologic screening, colposcopy, and testing for HPV DNA and other infections at each visit. RESULTS: Twenty-three HIV-seropositive women were matched with 23 seronegative women by cervical cytology reading, lifetime number of sexual partners, age, and follow-up length. Fourteen pairs of these women had follow-up visits every 4 months, for 56 and 53 total visits in seropositive and seronegative women, respectively. After matching, the groups had a similar overall prevalence of HPV DNA and of HPV oncogenic (high risk) types at baseline. On follow up, HIV-seropositive women were more likely than seronegative women to develop SIL (38% vs. 10%), less likely to have negative cytology (34% vs. 60%, overall P = 0.03), more visits with HPV DNA detected (68% vs. 40% P = 0.04), and more visits with multiple HPV DNA types detected (18% vs. 0%, P = 0.02). Colposcopic lesions in the seropositive women were more likely to have sharp borders or mosaicism or to be thick white (P = 0.009). CONCLUSIONS: After matching for baseline Papanicolaou smear readings, these data suggest that over time seropositive women have more visits that yield abnormal cytology, more persistent HPV DNA detection, and more colposcopic abnormalities than seronegative women.

Adult↗
PubMed1999

Effects of human immunodeficiency virus 1 infection on microbial origins of pelvic inflammatory disease and on efficacy of ambulatory oral therapy.

OBJECTIVE: This study was undertaken to determine the effects of human immunodeficiency virus 1 infection on the clinical presentation, severity, causal organisms, and response to ambulatory therapy of pelvic inflammatory disease. STUDY DESIGN: Women 18 to 40 years old with lower abdominal pain for <1 month were recruited. Participants underwent a standardized questionnaire, physical examination, screening for human immunodeficiency virus 1 and other sexually transmitted infections, and endometrial biopsy to detect plasma cell endometritis. Reevaluations were performed at 1 and 4 weeks to assess response to therapy. RESULTS: Among 162 women with adequate endometrial biopsy specimens 63 (39%) had histologically confirmed endometritis. Endometritis was more frequent among women who were seropositive for human immunodeficiency virus 1 than among women who were seronegative (odds ratio, 3.0; 95% confidence interval, 1.5-5.9). Infections with either Neisseria gonorrhoeae or Chlamydia trachomatis, or both, were least common and bacterial vaginosis was most common among human immunodeficiency virus 1-infected women with CD4 T-lymphocyte counts <400 cells/microL (P <. 04, P <.03, respectively). After oral antibiotic therapy, similar proportions of both women who were seropositive and women who were seronegative for human immuno-deficiency virus 1 had a >/=75% reduction in clinical severity score (81% vs 86%). CONCLUSION: Outpatient treatment of pelvic inflammatory disease was successful regardless of human immunodeficiency virus 1 serostatus.

Administration, Oral↗
PubMed1998

Outcomes among 562 recipients of placental-blood transplants from unrelated donors.

BACKGROUND: A program for banking, characterizing, and distributing placental blood, also called umbilical-cord blood, for transplantation provided grafts for 562 patients between August 24, 1992, and January 30, 1998. We evaluated this experience. METHODS: Placental blood was stored under liquid nitrogen and selected for specific patients on the basis of HLA type and leukocyte content. Patients were prepared for the transplantation of allogeneic hematopoietic cells in the placental blood and received prophylaxis against graft-versus-host disease (GVHD) according to routine procedures at each center. RESULTS: Outcomes at 100 days after transplantation were known for all 562 patients, and outcomes at 1 year for 94 percent of eligible recipients. The cumulative rates of engraftment among the recipients, according to actuarial analysis, were 81 percent by day 42 for neutrophils (median time to engraftment, 28 days) and 85 percent by day 180 for platelets (median, day 90). The speed of myeloid engraftment was associated primarily with the leukocyte content of the graft, whereas transplantation-related events were associated with the patient's underlying disease and age, the number of leukocytes in the graft, the degree of HLA disparity, and the transplantation center. After engraftment, age, HLA disparity, and center were the primary predictors of outcome. Severe acute GVHD (grade III or IV) occurred in 23 percent of patients, and chronic GVHD occurred in 25 percent. The rate of relapse among recipients with leukemia was 9 percent within the first 100 days, 17 percent within 6 months, and 26 percent by 1 year. These rates were associated with the severity of GVHD, type of leukemia, and stage of the disease. CONCLUSIONS: Placental blood is a useful source of allogeneic hematopoietic stem cells for bone marrow reconstitution.

Actuarial Analysis↗
PubMed1998

Vulvovaginal candidiasis: clinical manifestations, risk factors, management algorithm.

OBJECTIVE: To correlate symptoms, signs, and risk factors with positive wet mounts or cultures for Candida albicans and to develop an algorithm to diagnose vulvovaginal candidiasis. METHODS: This cross-sectional study of 774 randomly selected women from an urban sexually transmitted disease (STD) clinic evaluated symptoms, signs, and risk factors associated with C albicans, detected by wet mount and culture, and constructed an algorithm. RESULTS: C albicans, recovered from 186 (24%) of the 774 women, was associated with chief complaints of vulvar pruritus or burning. Elicited symptoms were vulvar pruritus, pain or burning, and external dysuria; signs were vulvar erythema, edema, fissures, vaginal erythema, and thick, curdy vaginal discharge. Among 545 women with symptoms of either increased vaginal discharge or vulvar pruritus or burning, only 155 (28%) had positive C albicans cultures, whereas bacterial vaginosis or other sexually transmitted infections were found in 288 (53%). In multivariate analysis, risk factors for positive C albicans culture included condom use, presentation after the 14th menstrual cycle day, sexual intercourse more than four times per month, recent antibiotic use, young age, past gonococcal infection, and absence of current gonorrhea or bacterial vaginosis. A clinical algorithm based on symptoms, signs, and selective use of wet mounts and cultures would have provided prompt treatment to 150 of 167 (90%) women with vulvovaginal candidiasis while minimizing the number of cultures performed. CONCLUSION: A simple algorithm using symptoms, signs, wet mounts, and selective cultures can identify 90% of women with vulvovaginal candidiasis. In this STD clinic, vulvovaginal symptoms also require assessment for bacterial vaginosis, trichomoniasis, and cervical infection.

Adolescent↗
PubMed1998

Use of nonoxynol-9 and changes in vaginal lactobacilli.

Several in vitro studies have shown nonoxynol-9 (N-9) to be toxic to lactobacilli, especially to strains that produce H2O2. Data from a randomized, double-blind, placebo-controlled crossover trial that investigated the safety and toxicity of 2 weeks of daily vaginal application of an N-9 gel were analyzed, to examine the effect of N-9 use on vaginal lactobacilli and bacterial vaginosis. In vivo, N-9 promoted sustained colonization by H2O2-producing lactobacilli among women already colonized (relative risk [RR], 1.8; 95% confidence interval [CI], 1.2-2.7). In addition, use of N-9 for 2 weeks reduced the likelihood of bacterial vaginosis (RR, 0.5; 95% CI, 0.3-1.0). In contrast, N-9 use by women initially colonized only by non-H2O2-producing lactobacilli resulted in loss of vaginal lactobacilli (RR, 2.5; 95% CI, 1.2-5.3). These data suggest that daily use of N-9 does not adversely affect vaginal colonization by H2O2-producing lactobacilli but that such use may promote loss of non-H2O2-producing strains.

Adult↗
PubMed1998

Radiologic percutaneous gastrostomy: results in 56 patients with head and neck cancer.

OBJECTIVE: The establishment of a direct enteral feeding route is critical in the overall treatment of many patients with head and neck cancer. Use of radiologic percutaneous gastrostomy (RPG), the newest technique for gaining enteral access, has not been studied in such patients extensively. This study evaluated the indications, technique, success rate, and complications associated with RPG in patients with head and neck cancer. STUDY DESIGN: Retrospective. METHODS: A comprehensive chart review was undertaken of 56 patients with head and neck cancer treated at a tertiary care institution who had undergone successful or attempted RPG at some point during their treatment course. RESULTS: Most study patients had advanced oropharyngeal squamous cell carcinoma. The most frequent indications for RPG were dysphagia/aspiration following tumor resection (n = 26) and dysphagia following completion of single- or combined-modality therapy (n = 22). The success rate of attempted RPGs was 98.2%. The overall complication rate for RPG was 12.7% (10.9% minor and 1.8% major). CONCLUSIONS: RPG is a valuable tool for establishing enteral nutrition in patients with head and neck cancer. Advantages of RPG include high success rate despite obstructing lesions, low complication rate, time efficiency and scheduling ease compared with intraoperative percutaneous gastrostomy (PEG) by a second team, no reported tumor seeding of the tube site, and the fact that postoperative RPG allows for more accurate selection of patients who require a gastrostomy tube.

Adult↗
PubMed1998

Contributions of microbes in vertebrate gastrointestinal tract to production and conservation of nutrients.

The vertebrate gastrointestinal tract is populated by bacteria and, in some species, protozoa and fungi that can convert dietary and endogenous substrates into absorbable nutrients. Because of a neutral pH and longer digesta retention time, the largest bacterial populations are found in the hindgut or large intestine of mammals, birds, reptiles, and adult amphibians and in the foregut of a few mammals and at least one species of bird. Bacteria ferment carbohydrates into short-chain fatty acids (SCFA), convert dietary and endogenous nitrogenous compounds into ammonia and microbial protein, and synthesize B vitamins. Absorption of SCFA provides energy for the gut epithelial cells and plays an important role in the absorption of Na and water. Ammonia absorption aids in the conservation of nitrogen and water. A larger gut capacity and longer digesta retention time provide herbivores with additional SCFA for maintenance energy and foregut-fermenting and copoprophagic hindgut-fermenting species with access to microbially synthesized protein and B vitamins. Protozoa and fungi also contribute nutrients to the host. This review discusses the contributions of gut microorganisms common to all vertebrates, the numerous digestive strategies that allow herbivores to maximize these contributions, and the effects of low-fiber diets and discontinuous feeding schedules on these microbial digestive processes.

Animals↗
PubMed1998

Risk assessment, symptoms, and signs as predictors of vulvovaginal and cervical infections in an urban US STD clinic: implications for use of STD algorithms.

OBJECTIVE: To identify clinical epidemiological correlates of cervical and vaginal infections and assess alternative algorithms, including two new reproductive tract infection (RTI) algorithms, for syndromic management of these infections. DESIGN, SETTING AND SUBJECTS: We prospectively studied clinical manifestations and risk correlates of cervical and vaginal infections in a randomly sampled group of 779 female patients seeking evaluation for a new problem at a Seattle STD clinic. METHODS: One experienced clinician performed standardised history, physical examination, and microscopy. Reference laboratories performed microbiological tests. Three levels of retrospective evaluation of algorithms included risk assessment and symptom review (RAS) alone; addition of speculum and bimanual examinations; and further addition of microscopy. RESULTS: (1) Chief complaint of abnormal vaginal discharge predicted a significantly lower rate of gonorrhoea (GC) or chlamydial infection (CT) than rates observed with no complaint of vaginal discharge. Only the elicited symptom of yellow vaginal discharge (not the more common symptoms of increased or malodorous vaginal discharge) predicted GC or CT. Chief complaint of abnormal vaginal discharge itself predicted trichomoniasis (TV) and bacterial vaginosis (BV), not cervical infection. Candida albicans was strongly associated with the chief complaint of vulvar pruritus, not with the chief complaint of abnormal vaginal discharge. (2) Applying these algorithms in STD clinics only to women with the chief complaint of abnormal vaginal discharge, rather than to all women, decreases sensitivity for GC or CT, without increasing positive predictive value (PPV). Criteria for inclusion of patients have more effect on the performance of these algorithms than do the levels of evaluation used. (3) A modified World Health Organisation (WHO) algorithm applied only to patients with symptoms of vaginal discharge, involving treatment of RAS positives for cervical infection, followed by treatment of vaginal infections and cervicitis based on examination of RAS negatives and positives, had a sensitivity of 50% and PPV of 33% for cervical infection, and very low sensitivity for BV, TV, and for vulvovaginal candidiasis (VVC). (4) An RTI algorithm derived from these data, and applied to all STD patients, involving RAS and examination of all RAS negatives, provided treatment to all cases of BV and TV associated with symptoms of vaginal discharge; treatment of all VVC associated with symptoms of vulvar pruritus; treatment for GC and GT to all RAS positives (using easily elicited risk factors) and to RAS negatives with signs of cervicitis or PID. This algorithm had a sensitivity of 87% and a PPV of 33% for GC or CT in this population, with its 24% prevalence of GC or CT. The sensitivity for BV, TV, and VVC greatly exceeded that of the modified WHO algorithm. (5) A modified RTI algorithm, involving examination rather than treatment of RAS positive women, no examination of RAS negatives, decreased the sensitivity for cervical infection to 55% but increased the PPV to 51%. CONCLUSIONS: Syndromic management of vaginal discharge offers relief of symptoms, prevention of transmission of trichomonas, and perhaps prevention of complications of BV. The 51% PPV of the modified RTI algorithm probably would warrant treatment and partner notification for GC and CT in settings with similar rates of GC and CT where more specific tests are lacking. However, as the prevalence of GC or CT decreases, the ratio of uninfected to infected who receive treatment with these algorithms would increase greatly, making the algorithms potential victims of their own success.

Adult↗
PubMed1997

Willingness to participate in HIV-1 vaccine efficacy trials and the effect of media events among gay and bisexual men in New York City: Project ACHIEVE.

Efficacy trials of candidate HIV-1 vaccines require study populations at high risk of infection who adhere to study protocols and who are willing to participate. Data from HIV-1 antibody-negative men (n = 698) enrolled in Project ACHIEVE in New York City were analyzed to assess willingness to participate in efficacy trials, factors influencing willingness, and the effect on willingness of the June 1994 media events about the decision not to proceed with phase III trials and about breakthrough infections during phase I and II vaccine trials. Sixty-eight percent indicated they would definitely or probably be willing to participate. Men enrolled during the time of media events were significantly less willing compared with men enrolled during other periods. These men were also more likely to mention safety of the vaccine, fear or mistrust of research or government, and social risks as important factors in their decision compared with men enrolled during other periods. The most frequently cited motivator for participation was altruism (57%); the most frequently cited barriers were vaccine safety (36%) and vaccine-induced seropositivity (19%). A substantial proportion of this cohort was willing to participate in future vaccine efficacy trials. However, because willingness may be affected by issues of vaccine safety, vaccine-induced seropositivity, and media coverage of these issues, significant efforts are needed for participant and community education, and specific concerns must be addressed in the design and implementation of trials.

Adult↗