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Biomedical subjects

J Anderson

Publications and source records attributed to J Anderson.

At least 253 records · Page 14Linked to original sources

Comparison of effects of suture materials on wound healing in a rabbit pyeloplasty model.

OBJECTIVES: To compare the effects of chromic catgut, polyglactic acid, polydioxanone (PDS), and polytrimethylene carbonate suture on urothelial healing in a rabbit model simulating pyeloplasty. METHODS: Pyeloureterotomies were performed on 8-week-old rabbits [12 rabbits (24 renal units) and 3 control rabbits] and closed with interrupted 7-0 sutures. At 10 days, 5 weeks, and 12 weeks postoperatively, we assessed the upper tracts by examining microscopic sections of the renal pelvis and upper ureter. Acute and chronic inflammation, foreign body reaction, and fibrosis/scar formation were assessed blindly and scored from 0 to 4. RESULTS: Histologic evidence of acute and chronic inflammation and foreign body reaction was most severe at 10 days and 5 weeks in pyeloureterotomies closed with chromic catgut. There was mild inflammation in those closed with polyglactic acid at 10 days, but it was minimal in those closed with polyglactic acid, PDS, and polytrimethylene carbonate at 5 and 12 weeks. Reabsorption of polyglactic acid was complete by 5 weeks, but was incomplete with the other three sutures at that time. By 12 weeks, there was persistent suture in 50% of the renal units closed with polydioxanone and in 100% of those closed with polytrimethylene carbonate. No animal developed a renal calculus. CONCLUSIONS: Because of the mild inflammatory response and rapid tissue reabsorption of polyglactic acid in this animal model, this suture appears to be the best suture for pyeloplasty.

Animals↗

Reduced superoxide dismutase in lung cells of patients with asthma.

Lung cells recovered from symptomatic patients with asthma generate increased amounts of reactive oxygen species (ROS). Animal and in vitro studies indicate that ROS can reproduce many of the features of asthma. The ability of ROS to produce the clinical features of asthma may depend on an individual's lung antioxidant defenses. Patients with asthma are reported to have reduced antioxidant defenses in peripheral blood, but little is known about the antioxidant defenses of their lung cells. To define lung cell antioxidant defenses in asthma, the glutathione concentration and the glutathione reductase, glutathione peroxidase, catalase, and superoxide dismutase (SOD) activities were measured in cells recovered by bronchoalveolar lavage (BAL cells) and by bronchial brushing (bronchial epithelial cells, HBEC) from normal subjects and patients with asthma. Superoxide dismutase activity was reduced 25% in BAL cells (p < .05) and nearly 50% in HBEC (p < .02) from patients with asthma. Alterations in the other antioxidants were not identified. A direct relationship was found between airway reactivity to methacholine, measured as PC(20)FEV(1), and HBEC SOD activity (r2 = 89; p < .005), but not between airway reactivity and the other antioxidants. The finding of reduced SOD activity in lung cells of patients with asthma suggests that diminished SOD activity serves as a marker of the inflammation characterizing asthma. Alternatively, it may play a role in the development or severity of the disease.

Antioxidants↗

Urethral cultures in female patients with a spinal cord injury.

Quantitative cultures of the urethral meatus were obtained from women with SCI undergoing intermittent catheterization. When compared with the urethral cultures of a group of female subjects, women with SCI had a greater number of isolates of Klebsiella pneumonia and Pseudomonas aeruginosa in the urethral flora. However there was not a significantly greater number of isolates or log numbers of E. coli or Enterococcus sp. in the urethral flora. The E. coli and Enterococcus sp. isolated from the urine were not isolated from the urethra of female patients with SCI in one third of the patients. This poor correlation between the simultaneous urethral and urine cultures of female subjects with SCI may reflect colonization of the urine with organisms that were unable to adhere to the mucosa and colonize the urethra. To what extent these organisms colonize or are temporary residents may be important in the pathogenicity of the infection.

Adult↗

HIV antibody testing: Genito-Urinary Clinic or additional site same-day testing service.

It has been suggested that different groups of individuals, possibly those at greater risk, may choose to attend anonymous HIV services not attached to Genito-Urinary Medicine Clinics. This paper reports the results of a comparative study of documented sociodemographic profile and risk category for individuals having HIV antibody tests at a Genito-Urinary Medicine Clinic and at an additional site same-day HIV antibody testing service not attached to a Genito-Urinary Medicine Clinic but within the same hospital. A retrospective case record analysis for 12 months from 1.10.93 to 30.9.94 was performed. During the 12-month study period 954 people had HIV testing at the additional site HIV antibody testing service and 803 had HIV antibody testing at the Genito-Urinary Medicine Clinic. Of those attending the additional site testing service 218 (22.9%) were homosexual/bisexual males as compared with 128 (15.9%) of the Genito-Urinary Medicine Clinic attendees (p < 0.01). A total of 22 (2.3%) of the individuals attending the additional site service gave a history of sexual contact in Africa as compared with 52 (65%) attending the Genito-Urinary Medicine Clinic (p < 0.001). There was no significant difference in the gender or age of those having HIV antibody tests at the two locations (p = 0.82 and p = 0.39 respectively). Four hundred and seventeen (52%) of the tests performed at the Genito-Urinary Medicine Clinic were performed on those who had not already decided to have a test before attending the clinic. Of those individuals who had decided to have a test before attending, 2.5 times as many attended the Same-Day Service as attended the Genito-Urinary Medicine Clinic (954 additional site attenders compared with 384 Genito-Urinary Medicine Clinic attenders). The results suggest that to optimize patient choice and benefit from a HIV antibody testing service this should be available at both Genito-Urinary Medicine Clinics and at additional site testing services.

Adult↗

Effect of pressure ulcers on the survival of long-term care residents.

BACKGROUND: Past studies have emphasized that patients with pressure ulcers are at high risk of dying. However, it remains unclear whether this increased risk is related to the ulcer or to coexisting conditions. In this study we examined the independent effect of pressure ulcers on the survival of long-term care residents. METHODS: We evaluated all 19,981 long-term care residents institutionalized in Department of Veterans Affairs (VA) long-term care facilities as of April 1, 1993. Baseline resident characteristics and survival status were obtained by merging data from five existing VA data bases. Survival experience over a 6-month period was described using a proportional hazards model. RESULTS: Pressure ulcers were present in 1,539 (7.7%) long-term care residents. Residents with pressure ulcers had a relative risk of 2.37 (95% CI = 2.13, 2.64) for dying as compared to those without ulcers. After adjusting for 16 other measures of clinical and functional status, the relative risk associated with pressure ulcers decreased to 1.45 (95% CI = 1.30, 1.65). No increased risk of death was noted for residents with deeper ulcers. CONCLUSIONS: Pressure ulcers are a significant marker for long-term care residents at risk of dying. After adjusting for clinical and functional status, however, the independent risk associated with pressure ulcers declines considerably. The fact that larger ulcers are not associated with greater risk suggests that other unmeasured clinical conditions may also be contributing to the increased mortality associated with pressure ulcers.

Activities of Daily Living↗

Determining the effectiveness of a clinical-practice intervention in improving the control of pain in outpatients with cancer.

PURPOSE: To determine the effectiveness of a clinical-practice intervention in improving the control of pain in outpatients with cancer. METHOD: Between July 5 and September 30, 1995, a randomized, controlled trial of 510 cancer outpatients and 13 oncologists was conducted at 23 clinics in Indiana. All the patients completed assessments of their pain, their pain regimens, and the degrees of relief received; they were surveyed again by mail four weeks after their clinic visits. The intervention group's clinical charts contained a summary of the completed pain scales; the oncologists who treated these patients were instructed to review the summary sheet prior to an evaluation. This summary was not available for the oncologists treating the patients in the control group. Each patient's pain management index (PMI) was calculated: the patient's pain medication level was rated on a scale of 0 to 3; the patients's pain level was rated on a scale of 0 to 3 and then subtracted from the first rating. A negative PMI was interpreted as representing insufficient treatment. Data were analyzed with several statistical tests. RESULTS: In all, only 320 patients who reported cancer-related pain were used in the analysis: 160 to 260 in the control group and 160 of 250 in the intervention group. The groups were similar with respect to demographics, cancer sites, and performance status. A significant difference (p = .0162) in the physicians' prescription patterns was found. In the control group, prescriptions for 86% of the patients did not change, with no decrease in analgesic prescriptions; for 14% of the patients analgesic prescriptions increased. In the intervention group, analgesic prescriptions changed for 25% of the patients, decreasing for 5% and increasing for 20%. A decrease in the incidence of pain described as more than life's usual aches and pains was found for the intervention group (p = .05). No significant difference was found between the groups for the patients undertreated for pain, as measured by PMIs. CONCLUSION: Although analgesic regimens were altered significantly when the physicians understood more about the patient's pain, cancer pain management remains a complex problem. Future studies should focus on the long-term systematic incorporation of simple pain-assessment tools into daily outpatient oncology practices as well as on innovative ways to address other aspects of managing cancer pain.

Adolescent↗

MHC-DRB allelic sequences incorporate distinct intragenic trans-specific segments.

The second exon of primate MHC-DRB genes encodes discrete areas of allelic hypervariability (HVR), which are used as the basis for lineage assignments to determine genetic and evolutionary relationships. Comparisons of these regions have led to the "trans-species hypothesis", which proposes that certain MHC alleles from one species are more closely related to those from other species than they are to each other; i.e., that allelic lineages are ancestral in origin. We evaluated this paradigm in an analysis of macaque and baboon MHC-DRB genes using oligotyping and sequencing of 87 new nonhuman primate DRB alleles. A remarkable conservation of sequence motifs in the HVRIII region (codon 60-79) was observed, detected both by hybridization and by sequencing; some of these motifs were found in species such as prosimians that have diverged from the human lineage 50 MYA. However, these fixed HVRIII motif sequences nevertheless occur on a background of diverse lineages suggesting that it is the segmental motif, rather than the allele per se which is trans-specific in origin. Sequences within the first hypervariable region (codons 7-14) identified lineage assignments to several DRB loci (DRB1, DRB3, DRB4, DRB5, DRB6 and DRB7), although a large number of DRB nucleotide sequences did not correspond to a defined allelic motif, suggesting that many of the nonhuman sequences lack human HVRI homologs and have accumulated additional intraspecies variation subsequent to speciation. While there are certain allelic lineages in HVRI that show trans-species conservation, other sequence motifs seem purely species-specific. These differences suggest that HVRI and HVRIII regions have distinct mechanisms for maintenance of trans-specific sequence elements, with different evolutionary histories for segmental nucleotide conservation.

Alleles↗

Predictors of pressure ulcer healing among long-term care residents.

OBJECTIVES: To identify predictors of pressure ulcer healing among long-term care residents. DESIGN: A retrospective cohort study. SETTING: Department of Veterans Affairs (VA) long-term care facilities. PARTICIPANTS: All long-term care residents with a pressure ulcer on April 1, 1993, who remained institutionalized as of October 1, 1993. Patients and pressure ulcer status were identified from the Patient Assessment File, a VA administrative database. MEASUREMENTS: Pressure ulcers were considered healed if patients were without an ulcer on October 1, 1993. Predictors of pressure ulcer healing were selected from among patient characteristics in the Patient Assessment File. RESULTS: Pressure ulcers were present in 7.7% of the long-term care residents institutionalized as of April 1, 1993. Among the 819 pressure ulcer patients remaining institutionalized as of October 1, 1993, ulcers had healed in 442 (54.0%). Seventy-two percent of patients with Stage 2 ulcers were ulcer-free at 6 months, compared with 45.2% of patients with Stage 3 ulcers and 30.6% of those with Stage 4 ulcers (P < .001). Significant (P < .05) independent predictors of healing included pressure ulcer size (Odds ratio (OR) = 5.2 for Stage 2 ulcers, OR = 1.5 for Stage 3 ulcers), older age (OR = 1.5), and receiving rehabilitation services (OR = 1.3 for each additional type of therapy). Both immobility (OR = .3) and incontinence (OR = .7) were associated with ulcers not healing. CONCLUSIONS: Most Stage 2 pressure ulcers, and many larger ulcers encountered in long-term care settings will heal. Baseline patient characteristics are important predictors of healing. Interventions may then be targeted at patients whose ulcers are unlikely to heal, and observed facility performance may be compared with expected outcomes.

Activities of Daily Living↗

Malignant sustained ventricular tachyarrhythmias in women: characteristics and outcome of treatment with an implantable cardioverter defibrillator.

Clinical rhythm, heart disease, ejection fraction, defibrillation threshold, recurrent arrhythmias, and mortality were compared in 268 consecutive recipients (213 men and 55 women) of their first implantable cardioverter defibrillator for life-threatening ventricular tachycardia or fibrillation. Women were younger than men, less likely to have structural heart disease, and more likely to have clinical ventricular fibrillation, a higher ejection fraction, and a lower defibrillation threshold. Complications of defibrillator placement were similar in both sexes. Unadjusted survival tended to be higher in women than in men (97% vs 90%, respectively, at 2 years, P = 0.08), largely due to fewer deaths from noncardiac causes or cardiac causes other than arrhythmia (P = 0.04). Women also tended to be at lower, albeit still substantial, risk for recurrent arrhythmias during follow-up (37% vs 52% in men at 2 years, P = 0.11). After adjustment for baseline differences, overall survival, arrhythmia death-free survival, nonarrhythmia death-free survival, and frequency of recurrent arrhythmias were not found to be gender related. Despite their apparent "lower risk" status on initial presentation, women remained at substantial risk for recurrent arrhythmias. This underscores the need to avoid being unduly biased by the "appearance" of health in managing women with malignant arrhythmias. That survival and other clinical endpoints were all ultimately independent of gender emphasizes the importance of other clinical variables in assessing risk from ventricular tachyarrhythmias.

Adult↗

Prospective evaluation of the effect of biphasic waveform defibrillation on ventricular pacing thresholds.

INTRODUCTION: Significant increases in ventricular pacing threshold have been observed following monophasic waveform ventricular defibrillation shocks. High-output pacing is recommended to ensure consistent capture, particularly in pacemaker-dependent patients who are likely to be defibrillated. Whether biphasic waveform defibrillation compounds this problem is not known. The purpose of this prospective study was to examine serial changes in ventricular pacing thresholds following single, multiple, low- and high-energy biphasic defibrillation shocks from an implanted defibrillator. METHODS AND RESULTS: Bipolar pacing thresholds before and after defibrillation, and the adequacy of pacing capture at three times preshock threshold in the immediate aftermath of ventricular defibrillation, were prospectively evaluated in 67 consecutively tested recipients of a biphasic implanted cardioverter defibrillator. Overall, serial pacing thresholds following successful defibrillation were completely unchanged after 141 of 177 (80%) ventricular fibrillation inductions. In no case did the threshold pulse width increment > 0.06 msec from its baseline value after shock, nor did pacing at a pulse width of three times preshock threshold from dedicated bipolar pacing electrodes fail to result in successful ventricular capture. Changes in threshold were not related to when measured from the time of shock, defibrillation energy, number of shocks, electrode system, chronicity of leads, shock orientation, or to clinical factors. CONCLUSIONS: No clinically important changes in pacing threshold were observed after biphasic waveform defibrillation. Bradycardia pacing at conventional pacemaker outputs of three times baseline pulse width threshold from bipolar electrodes dedicated exclusively to pacing or sensing (but not defibrillation) consistently allowed for an adequate safety margin following defibrillation.

Adult↗

Borrelia burgdorferi enzyme-linked immunosorbent assay for discrimination of OspA vaccination from spirochete infection.

Recombinant Lyme disease vaccines based on purified preparations of outer surface protein A (OspA) have been shown to be effective in preventing transmission of Borrelia burgdorferi in experimental animal models and are now being tested in humans. Since the most widely used screening tests for Lyme disease are based on a whole-cell sonicate of B. burgdorferi, serologic false positivity in vaccinated persons could result from reactivity to OspA within the antigen preparation. In order to avoid serologic false positivity in vaccinated subjects, we developed an immunoassay based on a low-passage-number, naturally occurring variant of B. burgdorferi which lacks the plasmid encoding OspA and OspB. The use of an antigen preparation derived from this organism provided sensitive and specific detection of B. burgdorferi seropositivity in experimental animals and in human Lyme disease cases. The OspA-B-negative enzyme-linked immunosorbent assay (ELISA) also appeared to be capable of discriminating the vaccinated state from vaccine failure and natural infection in experimental animals. Sera from human subjects participating in a vaccine trial gave false-positive results with an ELISA based on an OspA-containing strain, but no such reactivity was observed when the OspA-negative ELISA was used. We conclude that low-passage-number OspA-B-negative isolates in immunoassays may become useful for the immunologic discrimination of the vaccinated state, natural infection, and vaccine failure.

Antigens, Surface↗

Non-cultural detection of rectal and pharyngeal gonorrhoea by the Gen-Probe PACE 2 assay.

OBJECTIVE: To assess the sensitivity and specificity of the Gen-Probe PACE 2 assay, which uses a chemiluminescent labelled single-stranded DNA probe to detect gonococcal ribosomal RNA (rRNA), for the non-cultural detection of rectal and pharyngeal gonorrhoea in homosexual men. SUBJECTS: 161 homosexual men attending the Department of Genitourinary Medicine, Edinburgh Royal Infirmary during the latter half of 1995 and the first quarter of 1996. METHODS: Duplicate rectal and pharyngeal swabs were collected for culture on modified New York City (MNYC) medium and detection of gonococcal nucleic acid by the Gen-Probe assay. Repeatedly reactive Gen-Probe specimens from culture negative patients were also tested by the Gen-Probe competition assay (PCA). RESULTS: Of the 161 patients, 23 (14.3%) gave a positive culture at one or both sites (rectum 10, throat 8, rectum and throat 5) compared with 28 (16.7%) who gave a positive Gen-Probe result at one or both sites (rectum 9, throat 11, rectum and throat 8). After resolution of discrepant results by PCA the sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of Gen-Probe was 94.1%, 100%, 100% and 99.3% for rectal specimens while the corresponding values for pharyngeal specimens were 86.4%, 100%, 100%, and 97.9%. The sensitivity and NPV of rectal culture were 88.2% and 98.6% while the corresponding values for pharyngeal culture were 59% and 93.9%. Gen-Probe was significantly more sensitive than throat culture (p < 0.05) but not rectal culture (p > 0.2). The average Relative Light Units (RLU) value for the cut-off was 386 (range 351-450) while the average for a positive result was 20306 (range 403-110104): this was, however, significantly higher (p = 0.019) in rectal specimens 31325 (range 1705-110104) than in throat specimens 10447 (range 403-15633). CONCLUSIONS: Gen-Probe PACE 2 assay is a sensitive and specific method for the detection of rectal and pharyngeal gonorrhoea. As the Gen-Probe assay may detect nucleic acid from non viable gonococci the clinical significance of a probe positive culture negative specimen from a patient without culture evidence of gonorrhoea at another site is uncertain and requires further consideration. Nevertheless a positive result does indicate exposure to infection and could be important in ensuring appropriate partner notification action. If non-cultural methods are used to screen for gonococcal infection cultures should be obtained from patients with positive results in order that the antibiotic susceptibility and molecular epidemiology of the gonococcal population can be monitored.

Bacteriological Techniques↗

Factors that influence treatment decisions in childhood rhabdomyosarcoma. Intergroup Rhabdomyosarcoma Study Group of the Children's Cancer Group, the Pediatric Oncology Group, and the Intergroup Rhabdomyosarcoma Study Group Statistical Center.

PURPOSE: To correlate TNM stage with clinical group as a function of primary site in children with rhabdomyosarcoma. MATERIALS AND METHODS: In 547 children with nonmetastatic rhabdomyosarcoma, the disease was staged prospectively by using a TNM system and grouped according to resectability of the primary tumor. These factors were reviewed for each primary site. RESULTS: Primary tumor T status (T1, noninvasive; T2, invasive) was predictive of clinical group; 99 (36%) of 278 T1 tumors and 238 (88%) of 269 T2 tumors were nonresectable (clinical group III) (P < .0001). Tumor size (< or = 5 cm or > 5 cm) was also predictive of clinical group; 111 (46%) of 240 small tumors and 226 (74%) of 307 large tumors were nonresectable (P < .0001). Regional lymph nodes (N1) were found in 62 (24%) of 253 T2 tumors but in only 21 (8%) of 277 T1 tumors and in 67 (23%) of 294 large tumors but only 16 (7%) of 236 small tumors. Site of primary tumor was predictive of outcome and correlated with local treatment received. CONCLUSION: Local treatment, whether irradiation or resection, or both, should be determined according to TNM stage, age of child, and site of primary tumor. All children should receive chemotherapy. The goal of modern therapy is long-term survival, with maintenance of organ function and a good quality of life.

Child↗