Search PubMed⌕ Search

Biomedical subjects

J Reynolds

Publications and source records attributed to J Reynolds.

At least 109 records · Page 6Linked to original sources
PubMed1991

Transabdominal esophagomyotomy and partial fundoplication for treatment of achalasia.

The most common surgical treatment for achalasia is a modified anterior extramucosal esophagomyotomy. Unfortunately, a poor outcome may result secondary to recurrent dysphagia or gastroesophageal reflux. The reported incidence of reflux is 4 to 50 per cent. Our treatment for achalasia is an esophagomyotomy carried onto the cardia combined with a partial gastric fundoplication. Of 22 patients who presented with achalasia and moderate to severe symptoms of dysphagia and odynophagia, 19 had this procedure performed. Of these 19 patients, only two required a second procedure (postoperative dilatation) for recurrent symptoms. All three patients who had a full fundoplication required further surgical correction. Although fundoplication has been condemned in the past as treatment of achalasia to avoid the postoperative outcome of reflux, we have been successful with a partial fundoplication added to the standard esophagomyotomy. Given the fine line that needs to be tread to prevent recurrent signs and symptoms of achalasia or reflux when performing esophagomyotomy, our procedure offers a viable alternative to transthoracic esophagomyotomy alone.

Adult↗
PubMed1991

Intrathecal morphine in younger patients for postoperative pain following spinal fusion.

Intrathecal morphine in an average dose of 0.01 mg/kg was given to 33 patients between ages 11 and 16 years who had spinal arthrodesis for idiopathic scoliosis. The morphine was administered intrathecally as a 10 cc bolus at the conclusion of the arthrodesis, but before closure. The goal was to study safety in terms of respiratory depression and pain relief. Respirations occurred spontaneously in 30 of the 33 patients within 15 minutes of cessation of anesthesia. Respiratory depression occurred in five patients, four of whom had arterial blood pCO2 levels greater than 60 mm Hg. Thirty-one patients had relief of pain for 8 to greater than 40 hours, averaging 18 hours. Two patients had no noticeable pain relief. There appeared to be no relation between dose and pain relief in this limited dose range. We were unable to duplicate the long duration of pain relief reported elsewhere. We also were unable to decrease the side effects of respiratory depression and nausea to a level reported by others. It may be that the 10 cc bolus injected intrathecally circulates to the brain and ventricles faster than desired, or that factors relating to type of anesthesia or dose need to be considered. Low-dose intrathecal morphine does provide noticeable pain relief in younger patients undergoing spinal fusion. The side effects of nausea and respiratory depression can be managed safely with medication.

Adolescent↗
PubMed1991

A reconsideration of operations research experimental designs.

Of the three types of experimental designs used in social science research (true experiments, nonexperiments, and quasi-experiments), the most common in family planning OR are two quasi- and two nonexperimental designs. There has been a shift over time in the OR Program from true to quasi- and now, apparently, to nonexperimental designs. The strengths and weaknesses of these designs can be summarized as a tradeoff between greater validity and lower practicality, or greater practicality and lower validity. A number of suggestions have been made for improving the validity of nonexperimental designs or improving the practicality of quasi-experiments, but these suggestions do not significantly reduce the tradeoff. The designer, therefore, has to make a choice when selecting a design. With the current emphasis in the OR Program on providing useful information to managers, it may be time to include the managers in that decision, especially if they are to be the users of the results. It may also be time to look to other methodologies, particularly management science, for appropriate tools and techniques to use in family planning field settings. Nine criteria have been suggested for helping manager-researcher teams select an appropriate design: the time it takes to carry out a design, the cost involved, the expected utility of the results, the risk involved in accepting the results as valid, the audience that will use the results, the complexity of the issue to be studied, the state of existing knowledge about the subject, the difficulty of measuring the indicators selected, and the risk of contamination of control or experimental groups. Using these criteria, a researcher could help the manager decide how much of an investment to make in the study design. Nonexperimental designs could be applied to studies that can be done quickly, that are inexpensive, that involve low risk, that are limited to the manager as the audience, that are not complex, that have high utility, about which a good deal is already known, and for which the desired indicators are easy to measure. The more rigorous designs would be selected for studies that are at the other end of the continuum: that are lengthy, that are expensive, that are high-risk, that have multiple audiences, that are complex, about which little is known, that are difficult to measure, and that have a high chance of contamination. Obviously, no single methodology or study design should be applied to all OR problems. Experiments are important in certain circumstances, but not in all, perhaps not in many.(ABSTRACT TRUNCATED AT 400 WORDS)

Causality↗
PubMed1990

The variance of sample heterozygosity.

The variance of sample heterozygosity, averaged over several loci, is studied in a variety of situations. The variance depends on the sampling implicit in the mating system as well as on that explicit in the loci scored and individuals sampled. There are also effects of allelic distributions over loci and of linkage or linkage disequilibrium between pairs of loci. Results are obtained for populations in drift and mutation balance, for infinite populations undergoing mixed self and random mating, and for finite monoecious populations with or without selfing. For unlinked loci in drift/mutation balance, variances appear to be lessened more by increasing the number of loci scored than by increasing the number of individuals sampled. For infinite populations under the mixed self and random mating system, however, the reverse is true. Methods for estimating the variance of sample heterozygosity are discussed, with attention being paid to unbalanced data where not all loci are scored in all individuals.

Alleles↗
PubMed1990

Disseminated histoplasmosis in patients with AIDS.

Disseminated histoplasmosis was diagnosed in 36 (4%) of 980 patients with AIDS seen at Parkland Memorial Hospital in Dallas, Texas before September 30, 1989. Diagnostic sensitivity of blood culture plus examination of peripheral smear was 88%; sensitivity of bone marrow aspiration and blood culture was 80%. Median CD4 lymphocyte count at diagnosis was 33/cu mm. Median actuarial survival from the date histoplasmosis was diagnosed was 188 days. Thirteen (36%) of the 36 patients died before adequate antifungal therapy could be administered, while 13 survived long enough to receive 1,500 mg of amphotericin B; actuarial survival of the latter group from the date 1,500 mg of amphotericin B had been infused was 47% at 1 year. The substantial early mortality of AIDS-associated disseminated histoplasmosis and the modestly encouraging survival of those who were diagnosed in time to receive adequate therapy raise the issues of surveillance, prophylaxis, and empiric therapy for this infection in selected HIV-positive patients.

Acquired Immunodeficiency Syndrome↗
PubMed1990

Effects of chosen versus assigned jobs on the work performance of persons with severe handicaps.

We evaluated the effects of several choice-related variables on the work performance of adults with severe handicaps. After assessing client work preferences, three choice-related situations were presented: (a) providing clients with the opportunity to choose a work task, (b) assigning a preferred task, and (c) assigning a nonpreferred task. Results indicated that clients attended to work tasks almost twice as much when they chose their tasks and when assigned to work on preferred tasks versus when assigned to work on nonpreferred tasks. Results are discussed regarding the need to assess systematically the effects of choice-related variables.

Adult↗
PubMed1990

Abnormal vowel patterns in phonological disorder: some data and a hypothesis.

This article examines the vowel systems of a group of phonologically disordered children who show abnormalities in their vowel patterns. The conclusions emerging from the analysis of disordered speech are presented, along with examples from the data. It is argued that there are relatively common context-free processes of simplification of the vowel system in the data, and that these represent natural changes that may occur in normal development. Other less common processes may be idiosyncratic, and indicate some measure of disordered development. Some difficulties with vowels may relate to difficulties in the consonant system, or to difficulties with prosodic or paralinguistic features. Variability is an important part of the data, relevant to understanding the disorder and the process of development. It is hypothesised that the proposed framework will be relevant to clinical decision-making.

Child↗
PubMed1990

The ataxia-telangiectasia gene (ATA) on chromosome II is distinct from the ETS-1 gene.

We have studied the segregation of an RFLP detected with a human ETS-1 genomic probe in 25 families containing members affected with ataxia-telangiectasia (AT) and in 27 families from the Centre d'Etude du Polymorphisme Humain (CEPH) panel. We have recently mapped a gene for AT to 11q22-23 by linkage to the markers THY1 and D11S144. Multipoint linkage analysis of the CEPH families indicated that ETS-1 is located on chromosome 11q approximately 19.2 centimorgans telomeric to THY1. Analysis of the segregation of ETS-1 alleles in AT families yields strongly negative LOD scores, excluding an AT gene from a region extending 15 cM to either side of ETS-1. Multipoint mapping of ETS-1, D11S144, THY1, and AT also excludes the possibility that an AT gene is telomeric to ETS-1.

Ataxia Telangiectasia↗
PubMed1990

The curled catheter: dependable device for percutaneous peritoneal access.

The curled peritoneal dialysis catheter is theoretically less prone to catheter migration and drainage failure. It also allows percutaneous placement, rather than surgical placement exclusively, whenever desired or necessary. Review of 213 curled-catheter placements, 134 (63%) percutaneous and 79 (37%) surgical, over the last 4 years, shows that the probability of continuing catheter function by life-table analysis was 88% at one year, 71% at 2 years, and 61% at three years, with no difference comparing percutaneous to surgical placement. Among the 213 total cases, nearly 50% of all catheters were still functioning at last follow up, and 38 catheters (17.8%) have been lost in total, attributed to infectious complications in 24 cases (tunnel-exit infection alone in 5, peritonitis alone in 11, combined infection in 8), refractory drain failure in 9 cases (early drain failure in 4, late drain failure in 5), recurrent late subcutaneous dialysate leaking in 3 cases, and peri-catheter hernia in 2 cases. Among other complications, the incidence of early drain failure (7.0%), and late drain failure (4.2%), compare favorably to reports describing other devices or other placement methods having comparable size of reported experience. Analyzing our own percutaneous and surgical placements separately, there were no differences in the respective frequencies of early drain failure, late drain failure, late subcutaneous dialysate leaking, outer cuff extrusion, required hernia repair, peritonitis or tunnel-exit infection. Only early external dialysate leaking was more frequent using percutaneous placement methods (21.6% vs. 10.1%; p less than 0.05), although no catheters were lost due to early external leaking.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Cutaneous↗
PubMed1990

Effect of dietary protein and amino acids on immune function.

The normal immune system has local and systemic components which are influenced by a variety of alterations. Impaired host immunity is associated with neoplasia, protein calorie malnutrition, and the administration of immunosuppressive drugs. It is well accepted that protein calorie malnutrition impairs host immunity with particular detrimental effects on the T-cell system, resulting in increased opportunistic infection and increased morbidity and mortality in hospitalized patients. Individual nutrient substrates may also have a major influence on the immune system. Individual amino acids are often described as essential, based on requirements for optimal growth and maintenance of positive N balance. Arginine has been demonstrated to be essential to the traumatized host and may have tissue-specific properties which influence components of the immune system. Thus, arginine may be of value in clinical situations where the immune system is compromised. In a series of experiments in normal animals, arginine was demonstrated to enhance cellular immune mechanisms, in particular T-cell function. It also has a marked immunopreserving effect in the face of immunosuppression induced by protein malnutrition and increases in tumor burden. In postoperative surgical patients, arginine supplementation results in enhanced T-lymphocyte response and augmented T-helper cell numbers, with a rapid return to normal of T-cell function postoperatively compared with control patients. These data suggest that arginine supplementation may enhance or preserve immune function in high-risk surgical patients and theoretically improve the host's capacity to resist infection.

Amino Acids↗
PubMed1990

Protein-calorie malnutrition inhibits antitumor response to interleukin-2 immunotherapy.

The efficacy of systemic interleukin-2 (IL-2) immunotherapy is dependent on a competent host immune response. This study demonstrated that protein-calorie malnutrition (PCM) inhibited the generation of an antitumor response to IL-2. A/J mice received an isocaloric diet of 2.5% or 24% casein 8 weeks before inoculation with C1300 neuroblastoma cells. Three weeks later lymphocytes from tumor-bearing mice were harvested for determination of cytotoxic T-lymphocyte generation and natural killer cell cytotoxicity. PCM produced a significant reduction in total body weight (p less than 0.001) and serum albumin concentration (p less than 0.001). PCM inhibited generation of cytotoxic T lymphocytes (p less than 0.001), T-lymphocyte response in mixed lymphocyte reaction (p less than 0.001), and in vitro activation of natural killer cell cytotoxicity with IL-2 (p less than 0.001). A second experiment was performed to evaluate whether the in vitro deficits in tumor-specific and natural immunity in the animal model of PCM would diminish the efficacy of systemic high-dose IL-2 (3 x 10(6) units/kg three times daily for 5 days). The mean percent inhibition of C1300 growth with IL-2 was only 15% in mice with PCM compared with 60% in well-nourished mice (p less than 0.01). Median host survival time was greater in well-nourished animals (55 days) compared with animals with PCM (39 days) that received IL-2 (p less than 0.05). These data suggest that nutritional status is a critically important variable in tumoricidal response to systemic IL-2.

Animals↗
PubMed1989

Acinetobacter peritonitis during chronic peritoneal dialysis.

Among gram-negative bacilli isolated during peritonitis in chronic peritoneal dialysis (CPD), Pseudomonas species are most common but Acinetobacter species are nearly as frequent. A survey of more than 450 patient-years' experience with CPD revealed 23 episodes of Acinetobacter peritonitis (AP), making this the second most common form of gram-negative peritonitis. Concomitant break in sterile technique and exit-site/tunnel infection were infrequent. AP appeared as the first peritonitis episode in five cases and as the second in six cases, and the duration of CPD at the time of AP ranged from less than 1 to greater than 56 months. However, AP was noted to appear shortly after treatment of another peritonitis episode or shortly after CPD access placement, within 2 months in 11 cases (47%) and within 3 months in 14 cases (61%). Treatment with intraperitoneal antibiotics succeeded in 21 cases (91%) without CPD interruption or catheter removal, with tobramycin or gentamicin alone in 16 cases, and with combined aminoglycoside and penicillin or cephalosporin in six cases. In two cases intraperitoneal antibiotics alone were insufficient therapy: one case with concomitant tunnel infection and dialysate leak and one case with bacteremia while receiving corticosteroids. The time-dependent incidence of AP suggests opportunistic infection during a vulnerable period in the first 2 to 3 months following another peritonitis episode, but AP also appears amenable to intraperitoneal antibiotic therapy alone without interruption of the CPD routine in the majority of cases.

Acinetobacter Infections↗
PubMed1989

Disconnect during continuous ambulatory peritoneal dialysis (CAPD): retrospective experience with three different systems.

Disadvantages of continuous ambulatory peritoneal dialysis (CAPD), such as inconvenience and bulkiness of the apparatus, inflexibility of infusion volume, and predictable peritonitis incidence may be altered by using systems which allow disconnection from the tubing and bag after each exchange. At University of Michigan we have followed 35 patients using the O set with sodium hypochlorite (Baxter Healthcare Corp.) for 15.5 +/- 10 months, 16 patients using the Y configuration Ultraset (Baxter Healthcare Corp.) for 8.1 +/- 5 months, and 6 patients using a universal adapter (Delmed Corp.) for 14.3 +/- 7 months. Failure occurred in 7 cases (18%) at 12 +/- 8 months using the O set (3 elective, 3 related to peritonitis, 1 ultrafiltration difficulty), and 1 (7%) at 3 months using the Ultraset (related to peritonitis). Accidental sodium hypochlorite infusion occurred 8 times in 6 patients, 4 patients still on CAPD without residual effect and 2 in whom infusion contributed to failure but not to ultrafiltration difficulty. Cumulative per-patient-year (episode/months) peritonitis rates of 0.75 (1/16.4), 0.65 (1/18.4) and 0.88 (1/14.3), respectively, compare favorably with the overall center experience of 0.96 (1/12.2) (NIH-CAPD Registry). Peritonitis rates did not differ during use of any of the disconnect systems between patients with prior CAPD experience compared to patients without prior CAPD experience.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1988

Suppression of postprandial glucose, insulin, C-peptide, and glucose-dependent insulinotropic peptide (GIP) in man by oral administration of a prostaglandin analogue (enprostil).

Enprostil, a long-acting, orally active dehydroprostaglandin E2 with cytoprotective and gastric antisecretory properties, is a potent inhibitor of meal-stimulated gastrin release. Recent data have suggested suppression of additional other gastrointestinal peptide hormones following single doses of enprostil. The current investigation was conducted to further clarify the effects of enprostil administration on gastrointestinal hormones and glucose metabolism under physiologic conditions and to determine whether these effects were present following multiple doses of the agent. Enprostil 70 mcg/d and its placebo were each administered for 7 1/2 days to eight normal male subjects in a study of crossover design, each treatment period lasting 7 1/2 days and separated by a 7 day washout period. Subjects received a test meal on days 1 and 8 and an oral glucose challenge on day 3 of each treatment period following enprostil or its placebo. Following the test meal, there was a delay and suppression of the maximum measured serum glucose levels. Mean overall peak glucose concentrations were lower during the enprostil phase compared to placebo (112 vs. 121 mg/dd, P = 0.025) with a trend toward delay in the time to achievement of peak glucose concentrations. Mean overall peak levels for insulin, C-peptide, and glucose-dependent insulinotropic peptide (GIP) were significantly suppressed by 36%, 16% and 60%, respectively by enprostil when compared to placebo. The overall integrated postprandial responses for insulin, C-peptide, and GIP were significantly reduced by 42%, 39% and 90%, respectively while that for glucose above baseline was reduced by 44% (P = 0.098). Similar effects were present following the oral glucose challenge.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Oral↗
PubMed1988

Immune and metabolic effects of arginine in the surgical patient.

Arginine enhances immune function and promotes nitrogen retention in animal models, but its immunomodulatory effects in surgical patients are unknown. This randomized, prospective trial evaluated the immune and metabolic effects of supplemental L-arginine (25 g/day, n = 16) or isonitrogenous L-glycine (43 g/day, n = 14) in 30 cancer patients undergoing major operation. Two groups of patients received either arginine or glycine for 7 days after surgery as a supplement to a graduated enteral diet. Nitrogen balance was measured daily, and immune parameters were determined both before and after surgery, on Days 1, 4, and 7. The T-lymphocyte response to concanavalin A (con A) and PHA and dual marker phenotype analysis of lymphocyte (CD2, CD4, CD4/DR, CD8, CD8/DR) and macrophage (M3/DR) subsets were determined. Mean age, degree of preoperative weight loss, disease stage, number of perioperative transfusions, and calorie and nitrogen intake were similar for the groups studied. Mean daily nitrogen balance (-2.3 g/day in the arginine group vs. -3.9 g/day in the glycine group) was not significantly different between the two groups, but positive mean nitrogen balance was achieved only in the arginine group between Days 5 and 7 after surgery. Supplemental arginine significantly enhanced the mean T-lymphocyte response (stimulation index) to con A from 45 +/- 26 on postoperative Day 1 to 72 +/- 47 and 87 +/- 49 on postoperative Days 4 and 7, compared with the values of 29 +/- 15, 27 +/- 20, and 33 +/- 34 in the glycine group at the same time points, respectively. Supplemental arginine increased mean CD4 phenotype (% T-cells) on postoperative Days 1 and 7 from 25 +/- 9 to 43 +/- 14, compared with the values of 30 +/- 14 and 29 +/- 13 in the glycine group (p less than 0.05). The beneficial effect of arginine on the immune system appeared distinct from its more moderate effect on nitrogen metabolism. As a nutrient substrate, arginine was nontoxic, and may benefit surgical patients who are at increased risk of infection.

Aged↗
PubMed1988

A simplified low iodine diet in I-131 scanning and therapy of thyroid cancer.

A simplified, low iodine diet was developed for outpatient use prior to I-131 scanning and therapy in thyroid cancer. Iodine intake of five subjects on the diet was approximately 50 micrograms a day and this level was maintained for four weeks. The diet required only minimal instruction to be followed reliably. This level of iodine intake may increase radioiodine uptake in thyroid carcinomas.

Adult↗