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Biomedical subjects

R Nelson

Publications and source records attributed to R Nelson.

At least 37 records · Page 2Linked to original sources
PubMed2003

Non surgical therapy for anal fissure.

BACKGROUND: Because of the disability associated with surgery for anal fissure and the risk of incontinence, medical alternatives for surgery have been sought. Most recently, pharmacologic methods that relax the anal smooth muscle, to accomplish reversibly what occurs in surgery, have been used to obtain fissure healing. OBJECTIVES: To assess the efficacy and morbidity of various medical therapies for anal fissure. SEARCH STRATEGY: Search terms include "anal fissure randomized". SELECTION CRITERIA: Studies in which participants were randomized to a non-surgical therapy for anal fissure. Comparison groups may include an operative procedure, an alternate medical therapy or placebo. Chronic fissure, acute fissure and fissure in children are included in the review. Atypical fissures associated with inflammatory bowel disease or cancer or anal infection are excluded. DATA COLLECTION AND ANALYSIS: Data were abstracted from published reports and meeting abstracts, assessing method of randomization, blinding, "intention to treat" and drop-outs, therapies, supportive measures (applied to both groups), dosing and frequency and cross-overs. Dichotomous outcome measures included Non-healing of the fissure (a combination of persistence and recurrence), and Adverse events (including incontinence, headache, infection, anaphylaxis). Continuous outcome measures included measures of pain relief and anorectal manometry. MAIN RESULTS: 21 different comparisons of the ability of medical therapies to heal anal fissure have been reported in 31 RCTs. Nine agents were used (nitroglycerin ointment (GTN), isosorbide dinitrate, Botulinum toxin (Botox), diltiazem, nifedipine (Calcium channel blockers or Cachablos), hydrocortisone, lignocaine, bran, placebo) as well as anal dilators and surgical sphincterotomy. When two studies are excluded from analysis due to quality concerns, the significance disappears in the three main analyses: GTN vs. placebo group (0.78; 0.56-1.08), in children (0.96; 0.48-1.92) and adults (0.73; 0.50-1.07). That is, GTN was, in this modified analysis, not significantly better than placebo in curing anal fissure. Cachablos were not tested against placebo, but in a comparison to GTN, Cachablo was equivalent in its ability to cure fissure (odds ratio 0.66; 0.22-2.01). Botox, in a meta-analysis of two studies compared to placebo, showed no significant advantage in efficacy (0.75; 0.32-1.77), and in a comparison to GTN analyzing two studies, was also not significantly better than GTN (0.48; 0.21-1.10). REVIEWER'S CONCLUSIONS: Medical therapy for chronic anal fissure, acute fissure and fissure in children may be applied with a chance of cure that is only marginally better than placebo, and, for chronic fissure in adults, far less effective than surgery.

Fissure in Ano↗
PubMed2003

Clinical experience with porous tantalum cervical interbody implants in a prospective randomized controlled trial.

A prospective randomized study was undertaken to evaluate the radiological appearance and clinical effectiveness of two porous tantalum (Hedrocel) implants in achieving a stable cervical interbody fusion. A prerandomization protocol was used to allocate patients to the three arms of the study: a ring implant containing autologous cancellous bone graft, a solid block implant or autologous tricortical iliac crest bone graft. Patients were followed for 2 years with plain radiological studies, SF-36, and Neck Disability Index questionnaires and neurological assessment. Early in the study the postoperative radiographs of four patients receiving Hedrocel implants showed inferior end-plate lucency raising concerns about delayed or non-fusion. Recruitment to the study was halted by the investigators to allow longer-term follow-up of the implanted patients when only 24 patients had been recruited to the study. Although fusion was subsequently noted in all patients at 12 months there was no further enrolment to the study. At 2 years the radiological and clinical outcomes of the three groups appeared comparable, but the study numbers were too small for any statistical analysis. This study highlights the difficulties that can arise when clinical caution takes precedence over objective measures of clinical progress during a study. In the absence of an independent safety monitoring committee, the investigators were under an ethical obligation to suspend recruitment to this study, until it was clear that the radiological features were not associated with poor clinical outcomes. The use of safety monitoring committees and the clarification of stopping criteria in relation to outcome measures should be considered in open randomized trials of spinal surgical techniques and implants.

Adult↗
PubMed2003

The impact of abnormal fetal echocardiography on expectant parents' experience of pregnancy: a pilot study.

To examine the impact of an abnormal fetal echocardiogram (echo) on parental attitudes, emotions and coping strategies. Group interviews were performed for women and their male partners who had a fetal echo and were found to have a fetal congenital heart defect. The women and men were separated into four different focus groups. The interviews were tape recorded, transcribed and analyzed. The women expressed strong emotions of guilt, fear and sadness or hopelessness. They coped by attaching and bonding to the fetus, and were realistic about the future. The women began grieving at the time of the fetal echo. The men experienced emotions of anger and anxiety. They coped by remaining optimistic, and focused on supporting their wives. Men grieved after the birth of the baby. The fetal echo was felt to be beneficial and not harmful by the parents. The fetal echo led to significant changes in the couples' perceptions of themselves and their relationships. Clinicians performing fetal imaging must be aware of parental affective responses and coping mechanisms in order to provide the required psychological support.

Adaptation, Psychological↗
PubMed2002

Primary repair for penetrating colon injuries.

BACKGROUND: Primary repair of penetrating colon injuries is an appealing management option, however uncertainty about its safety persists. OBJECTIVES: The objective of this review was to compare the morbidity and mortality of primary repair to fecal diversion in the management of penetrating colon injuries using a meta-analysis of randomized controlled trials. SEARCH STRATEGY: We searched MEDLINE (1966 to November 2001), the Cochrane Controlled Trials Register, and EMBASE using the terms colon, penetrating, injury, colostomy, prospective, and randomized. SELECTION CRITERIA: Studies were included if they were randomized controlled trials comparing the outcomes of primary repair versus fecal diversion in the management of penetrating colon injuries. Five studies were included. DATA COLLECTION AND ANALYSIS: Reviewers performed data extraction independently. Outcomes evaluated from each trial included mortality, total complications, infectious complications, intra-abdominal infections, wound complications, penetrating abdominal trauma index (PATI), and length of stay. Peto odds ratios for combined effect were calculated with a 95% confidence interval for each outcome. Heterogeneity was assessed for each outcome using a chi-squared test. MAIN RESULTS: The Penetrating Abdominal Trauma Index (PATI) of included subjects did not significantly differ between studies. Mortality was not significantly different between groups (OR 1.70, 95% CI 0.51,5.66). However, total complications (OR 0.28 95% CI 0.18,0.42), total infectious complications (OR 0.41, 95% CI 0.27, 0.63), abdominal infections including dehiscence (OR 0.59, 95% CI 0.38,0.94), abdominal infections excluding dehiscence (OR 0.52 95% CI 0.31,0.86), wound complications including dehiscence (OR 0.55, 95% CI 0.34,0.89), and wound complications excluding dehiscence (OR 0.43, 95% CI 0.25,0.76) all significantly favored primary repair. REVIEWER'S CONCLUSIONS: Meta-analysis of currently published randomized controlled trials favors primary repair over fecal diversion for penetrating colon injuries.

Colon↗
PubMed2002

The role of the French midwives in establishing the first special care units for sick newborns.

At the end of the 19th century, under Dr. Tarnier's direction, the first trials of incubators were performed at the Paris Maternity. The success led to the construction of a special pavilion for sick newborns. The midwife-in-chief, Mrs. Henry, raised the funds for the construction. The results of the initial trial are reported. In 1892, the successor of Dr. Tarnier, Dr. Budin, the Chair of Obstetrics, did not approve of the condition of the nursery. Mrs. Henry left abruptly. The unit was placed under medical direction in order to bring a scientific approach to the care of the sick newborns. Stepdown units called pouponnieres were created to assure the transition of the infants to the home and decrease neonatal mortality.

France↗
PubMed2001

The significance of bcr-abl molecular detection in chronic myeloid leukemia patients "late," 18 months or more after transplantation.

The bcr-abl chimeric messenger RNA is frequently detected in chronic myeloid leukemia (CML) patients after bone marrow transplantation. It was previously reported that the relapse risk of bcr-abl detection 6 to 12 months after transplantation was greater than 40%. This risk decreased as the time between transplantation and detection increased. To further define the relapse risk associated with bcr-abl molecular detection in "late" CML survivors, 379 consecutive CML patients alive at 18 months after transplantation or later were studied. Ninety of 379 patients (24%) had at least one positive bcr-abl test 18 months after transplantation or later; 13 of 90 bcr-abl-positive patients (14%) and 3 of 289 bcr-abl-negative patients (1.0%) relapsed. The median time from bcr-abl detection to relapse was 916 days (range, 251-2654 days). The hazard ratio of relapse associated with bcr-abl detection was 19.2 (P <.0001). The stage of disease, chronic graft-versus-host disease, and the donor type did not alter the association between bcr-abl and relapse. Quantification of bcr-abl was performed on 344 samples from 85 bcr-abl-positive patients by means of a real-time quantitative reverse transcriptase-polymerase chain reaction assay. The median bcr-abl change of patients who relapsed was significantly greater than those that remained in remission (P =.002). The median bcr-abl level at relapse was 40 443 bcr-abl copies per microg RNA (range, 960-299 552). Of 73 bcr-abl-positive patients who failed to relapse, 69% had only one positive test at a median of 24 copies bcr-abl per microg RNA. The detection of bcr-abl is common following transplantation. The prognostic significance of a qualitative bcr-abl can be refined by quantitative assays and thus may target patients who would benefit from early intervention.

Adolescent↗
PubMed2001

Operative procedures for fissure in ano.

BACKGROUND: Operative techniques commonly used for fissure in ano include: anal stretch, open lateral sphincterotomy, closed lateral sphincterotomy, posterior midline sphincterotomy and to a lesser extent dermal flap coverage of the fissure. Reports of direct comparisons between operative techniques for anal fissure are variable in their results. These reports are either subject to selection bias (in non-randomized studies) or observer bias (in almost all studies) or have inadequate numbers of patients enrolled to answer the question of efficacy. OBJECTIVES: To determine the best technique for fissure surgery. SEARCH STRATEGY: MEDLINE and the Cochrane Library were searched using the key words: "surgery, anal fissure". Additional search terms such as "anal sphincterotomy" and "anal fissure therapy" disclosed no additional reports. The list of cited references in all included reports also was helpful in finding additional comparative studies. SELECTION CRITERIA: All reports in which there was a direct comparison between at least two operative techniques were reviewed and when more than one report existed for any given pair, that report was included. If crude data were not presented in the report, the authors were contacted and crude data obtained. DATA COLLECTION AND ANALYSIS: The two most commonly used end points in all reported studies were persistence of the fissure and post operative incontinence of flatus. These are the only two endpoints included in the meta-analysis. MAIN RESULTS: Anal stretch has a higher risk of fissure persistence than internal sphincterotomy and also a significantly higher risk of minor incontinence than sphincterotomy. The combined results of open versus closed partial lateral internal sphincterotomy show little difference between the two procedures both in fissure persistence and risk of incontinence. REVIEWER'S CONCLUSIONS: Anal stretch and posterior midline internal sphincterotomy should probably be abandoned in the treatment of chronic anal fissure in adults. For those patients requiring surgery for anal fissure, open and closed partial lateral internal sphincterotomy appear to be equally efficacious. More data are needed to assess the effectiveness of posterior internal sphincterotomy.

Anal Canal↗
PubMed2001

What role does full rectal mobilization alone play in the treatment of rectal prolapse?

Rectal mobilization is a component of many operations for the treatment of rectal prolapse. How much of the successful treatment of this condition is due to this procedure alone has not been previously investigated. Full posterior rectal mobilization was done alone without sigmoid resection or rectopexy in thirteen patients. Of the thirteen patients with a mean follow-up of 33.4 months, there have been one early and one late recurrence. One further patient had a anterior mucosal prolapse at 1 year. Ten patients remain recurrence-free. In conclusion, rectal mobilization alone gives results close to more extensive operations and may be the major component of their success. In addition it may have less risk of sepsis.

Adolescent↗
PubMed2001

Genetic susceptibility to MS: a second stage analysis in Canadian MS families.

Four published genome screens have identified a number of markers with increased sharing in multiple sclerosis (MS) families, although none has reached statistical significance. One hundred and five markers previously identified as showing increased sharing in Canadian, British, Finnish, and American genome screens were genotyped in 219 sibling pairs ascertained from the database of the Canadian Collaborative Project on Genetic Susceptibility to MS (CCPGSMS). No markers examined met criteria for significant linkage. Markers located at 5p14 and 17q22 were analyzed in a total of 333 sibling pairs and attained mlod scores of 2.27 and 1.14, respectively. The known HLA Class II DRB1 association with MS was confirmed (P<0.0001). Significant transmission disequilibrium was also observed for D17S789 at 17q22 (P=0.0015). This study highlights the difficulty of searching for genes with only mild-to-moderate effects on susceptibility, although large effects of specific loci may still be present in individual families. Future progress in the genetics of this complex trait may be helped by (1) focussing on more ethnically homogeneous samples, (2) using an increased number of MS families, and (3) using transmission disequilibrium analysis in candidate regions rather than the affected relative pair linkage analysis.

Canada↗
PubMed2001

Noncytolytic human lymphocytes injure dermal microvessels in the huPBL-SCID skin graft model.

Recent transplantation experiments using perforin-deficient mice as allograft recipients have challenged the concept that allograft rejection is mediated exclusively by CTL. We sought to determine if human noncytolytic lymphocytes could mediate rejection of allogeneic human skin grafts in the huPBL-SCID mouse model of rejection. We generated short term lines of human lymphocytes from peripheral blood mononuclear cells using PHA as a mitogen. The first group was stimulated with PHA alone, the second with PHA plus IL-4 and neutralizing antibody to IL-12, and in the third group PBL were depleted of B cells and monocytes before stimulation as in group 2. After two passages, lines were tested for cytolytic ability and IFN-gamma production. Each line was injected i.p. to mice bearing allogeneic skin grafts. The grafts were harvested between day 16 and 21 after PBL injection, then the histology was scored by a blinded observer for degree of infiltration, microvessel injury, induction of epidermal MHC class II, and perforin expression. In vitro we found that PBL in groups 2 and 3 were unable to lyse cultured endothelial cells in a lectin-directed 111In release assay. In vivo 80% of the IL-4/anti-IL-12 groups maintained the IFN-gamma-low phenotype, and no perforin was detected in these grafts. Nevertheless, human microvessel injury was similar between the two groups. This was not antibody-dependent since the B-cell-depleted group showed similar injury. Moreover adjacent murine vessels were intact. We interpret these observations to show (1) these human PBL lines maintained their phenotype following in vivo restimulation, and (2) noncytolytic graft-infiltrating lymphocytes specifically promote injury of allogeneic human microvessels.

Animals↗
PubMed2001

Of holes and wholes: the perception of surrounded regions.

Fully enclosed regions in a two-dimensional image can often be perceived either as an object in front of a surface or as a hole through a surface. Several experiments were conducted to determine what factors affect perception of holes versus objects. Three types of factors were tested and found to influence this outcome. First, depth factors directly indicate that the enclosed region lies behind its surrounding surface. Second, grouping factors relate the enclosed region to an outer region that is generally perceived as a continuation of the surface seen through the hole. Finally, figural factors indicate whether the enclosed region is to be perceived as figure or ground. Relations among these factors and their implications for perceptual organization are discussed.

Analysis of Variance↗