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Biomedical subjects

J Reynolds

Publications and source records attributed to J Reynolds.

At least 19 recordsLinked to original sources
PubMed1992

The correlation of visual function with posterior retinal structure in severe retinopathy of prematurity. Cryotherapy for Retinopathy of Prematurity Cooperative Group.

The Multicenter Trial of Cryotherapy for Retinopathy of Prematurity previously reported reduced incidence of both poor structural and functional outcomes after cryotherapy. We compared the results in 304 eyes of patients in the randomized portion of the trial in whom both structural and functional assessments were performed 12 months after randomization. Two hundred fifty-five eyes (83.9%) had concordant outcomes: 153 eyes had favorable structural and functional outcomes and 102 eyes had unfavorable structural and functional outcomes. Twenty-nine eyes (9.5%) had discordant outcomes: 20 eyes had favorable structural and unfavorable functional outcomes and nine eyes had unfavorable structural and favorable functional outcomes. The small number of discordant outcomes could generally be accounted for by three factors: (1) retinal abnormalities beyond those considered in the photographic grading system (12 eyes), (2) nonretinal visual pathway disease (five eyes), or (3) false-positive and false-negative results in the measurement systems used to evaluate structure and function (five eyes). In 20 eyes (6.6%), photographs could not be graded or the visual acuity was untestable. We conclude that the appearance of the posterior pole of the eye correlates well with grating acuity in the 12-month-old infant with a history of severe retinopathy of prematurity.

Cryosurgery↗
PubMed1992

Development of myopia in infants with birth weights less than 1251 grams. The Cryotherapy for Retinopathy of Prematurity Cooperative Group.

The authors report on the incidence of myopia in a large group of premature infants with birth weights of less than 1251 g followed as part of the multicenter study of Cryotherapy for Retinopathy of Prematurity. None of the eyes reported here underwent cryotherapy. Eyes were refracted using cycloplegic retinoscopy at 3 months (n = 2916), 12 months (n = 2626), and 24 months (n = 961 at 5 of the 23 centers) after term. Myopia was observed in approximately 20% of the children at each test age. The percentage of high myopia (greater than or equal to 5 diopters) doubled from 2% to 4.6% between 3 and 12 months and remained stable thereafter. Lower birth weight and increasing severity of retinopathy of prematurity (ROP) were strong predictors of myopia and high myopia. In addition, anisometropia, astigmatism, and the presence of posterior pole residua from ROP also were associated with a higher incidence of myopia and high myopia.

Anisometropia↗
PubMed1992

Response to steroid and duration of radicular pain as predictors of surgical outcome.

Prolonged structural compromise of spinal nerve roots can lead to chronic changes that surgical decompression might not be able to reverse. In this study, it was hypothesized that if there were a reversible structural pain component, a steroid injected into the patient's symptomatic nerve root should provide temporary pain relief and that these patients should have a favorable surgical outcome. It also was hypothesized that duration of radicular symptoms would correlate inversely with surgical outcome. For postoperative relief of radicular pain, the results showed that patients with pain lasting less than 1 year had a positive surgical result (89%), regardless of response to steroid. Patients with pain lasting more than 1 year and who have had a positive response to steroid injected into the symptomatic nerve root (roots) had a positive surgical outcome of 85%. Patients who did not respond to the steroid and had pain for more than 1 year (95%) generally had a poor surgical outcome. Although the poor outcome in the last group might be explained in some cases by an inadequate structural correction, inadequate stabilization, or functional reasons, the majority of these failures represented irreversible changes in the neural structures.

Betamethasone↗
PubMed1992

A novel peptide-producing cell in Xenopus: multinucleated gastric mucosal cell strikingly similar to the granular gland of the skin.

We have characterized a novel peptide-containing cell within the gastric mucosa of Xenopus laevis. The cell is a spherical, multinucleated syncytial structure containing a cytoplasmic space filled with dense rice-shaped granules, and is strikingly similar in morphology to the well-studied granular gland of the amphibian skin. Immunohistochemical and immunogold methods were used to demonstrate that several peptides previously isolated from the granular glands of the skin, including the antimicrobial peptides magainin and PGLa (a peptide with amino-terminal glycine and carboxy-terminal leucinamide), are also stored in granules present in these enteric cells. These data demonstrate that this enteric peptide-producing cell is strikingly similar both morphologically and biochemically to the granular gland, previously considered a highly specialized structure of the amphibian integument. This novel gastric mucosal cell, which we have designated a "granular multinucleated cell," is distinct in its morphology and its diversity of stored peptide products from other well-characterized peptide-containing cells in the vertebrate gastrointestinal tract.

Amino Acid Sequence↗
PubMed1991

Thyroid cancer: a lethal endocrine neoplasm.

This conference focuses on the controversies about managing thyroid cancer, emphasizing the possibility that the treatment of patients with potentially fatal thyroid cancer may be improved. Although the mortality rate from thyroid cancer is low, it is the highest among cancers affecting the endocrine glands (excluding the ovary). Exposure to radiation during childhood in the 1930s and 1940s increased the incidence of but not the mortality from thyroid cancer, because these tumors are mainly papillary cancers developing in young adults. These rates may change as the exposed cohort ages. Risk factors that increase mortality include older patient age and the growth characteristics of the tumor at diagnosis, the presence of distant metastases, and cell type (for example, the tall-cell variants of papillary cancer, follicular cancer [to be distinguished from the more benign follicular variant of papillary cancer], medullary cancer, and anaplastic cancer). Local metastases in lymph nodes do not seem to increase the risk for death from papillary cancer, but they do increase the risk for death from follicular and medullary cancer. In the latter, mortality is decreased by the early detection and treatment of patients with the familial multiple endocrine neoplasia syndrome 2a. There are excellent tumor markers for differentiated cancer of the parafollicular and of the follicular cells (serum calcitonin and serum thyroglobulin levels, respectively). Measuring the calcitonin level allows early diagnosis of familial medullary cancer, whereas measuring the thyroglobulin level, although useful only after total thyroidectomy, allows early recognition of recurrence or metastases of papillary or follicular cancer. Initial surgery, protocols for follow-up, and the use of radioiodine for the ablation of any residual thyroid and the treatment of metastatic cancer are discussed. Because these tumors resist currently available chemotherapy regimens, possible ways to increase the effectiveness of radioiodine therapy are considered as are new approaches to treatment.

Carcinoma↗
PubMed1991

Simultaneous catheter replacement and removal in refractory peritoneal dialysis infections.

The present report describes more than nine years of experience with simultaneous removal and replacement of the chronic peritoneal dialysis (PD) catheter in treating refractory mechanical and infectious complications. Simultaneous catheter replacement and removal not only succeeded in 22 of 23 cases with non-infectious mechanical complications, allowing uninterrupted PD in all but three, but also succeeded in 30 (83%) of 36 additional cases with persisting or recurring infection. Simultaneous procedures failed in six (17%) of 36 infectious cases, due to persistent infection in two cases and to procedure complications in four cases. The clinical characteristics of the 30 successful infectious cases were compared to the characteristics of both the six failures, as well as 29 additional infectious cases in which the peritoneal catheter was removed but was not replaced because of a variety of serious complications (such as pancreatitis, abscess, sepsis, or fluid overload). At the time of simultaneous catheter replacement in successful cases, temporary control of active peritoneal inflammation was achieved more frequently (80% vs. 31%, P less than 0.001) with a shorter interval of antibiotic coverage (6.4 +/- 0.9 vs. 14.7 +/- 1.3 days, P less than 0.001). In addition, the successful cases were characterized by significantly more Staphylococcal infections (70% vs. 26%, P less than 0.001) and significantly fewer Pseudomonal or fungal infections (6% vs. 59%, P less than 0.001), although successful cases included some non-Pseudomonal, non-enteric gram negative infections (23%).(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1991

Cyclosporin A in the prevention and treatment of experimental autoimmune glomerulonephritis in the brown Norway rat.

Experimental autoimmune glomerulonephritis (EAG) was induced in brown Norway (BN) rats by a single i.m. injection of collagenase-solubilized homologous glomerular basement membrane (GBM) in Freund's complete adjuvant. This model of anti-GBM disease is characterized by the development, over several weeks, of circulating and deposited anti-GBM antibodies, accompanied by albuminuria. We examined the effects of treatment with oral cyclosporin A (CsA) at different doses, starting at the time of immunization and during the course of the disease. Pretreatment with CsA 5 mg kg daily produced a moderate reduction in circulating anti-GBM antibody levels, reduced deposition of antibody on the GBM and decreased albuminuria. Doses of 10 and 20 mg/kg CsA produced a marked reduction in circulating antibody, absence of detectable deposited antibody and virtual absence of albuminuria. Renal function remained normal in CsA-treated and control animals. When CsA treatment was introduced at 2 or 4 weeks after immunization, there were significant effects on the subsequent autoimmune response and albuminuria at 10 and 20 mg/kg daily. These studies demonstrate that CsA in conventional doses has a therapeutic effect in this model of anti-GBM disease, and suggest a role for T lymphocytes in the pathogenesis of EAG.

Administration, Oral↗
PubMed1991

Preventing Staphylococcus aureus infection during chronic peritoneal dialysis.

In the interest of studying the prevention of chronic peritoneal dialysis infections, serial studies of the bacterial epidemiology in peritonitis and of antibiotic prophylaxis, respectively, were carried out. For 18 months, prospective evaluation of catheter exist site cultures, performed at the time patients developed acute peritonitis, showed that Staphylococcus aureus peritonitis was associated with concordant S. aureus at the exist site in 85% of cases, significantly more frequent than that for other organisms (P less than 0.02). Furthermore, active inflammation along with concordant culture results at the exit site characterized more than 60% of S. aureus peritonitis cases, also significantly more than that for other organisms (P less than 0.01). Over the ensuing 2 yr, patients beginning chronic peritoneal dialysis with a new percutaneously placed catheter were prospectively entered into a randomized, controlled trial of long-term antibiotic prophylaxis with trimethoprim-sulfamethoxasole. Patients receiving prophylaxis tended to have fewer episodes of peritonitis; however, the lower rate of peritonitis reached statistical significance only comparing patients who were S. aureus carriers at entry into the study to patients who were not S. aureus carriers. In particular, the prophylaxis trial seemed to reduce the specific incidence of S. aureus peritonitis overall, with S. aureus appearing in only 2 of 28 total peritonitis episodes among treated patients as compared with 11 of 37 total episodes among non-treated patients (P less than 0.01). Further analysis of the time to first peritonitis suggests that the effect of prophylaxis was most prominent during the first 3 months of therapy (P less than 0.02) rather than later in the course of treatment.(ABSTRACT TRUNCATED AT 250 WORDS)

Actuarial Analysis↗
PubMed1991

Intrathecal morphine: dosage and efficacy in younger patients for control of 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

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↗