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Biomedical subjects

J Reynolds

Publications and source records attributed to J Reynolds.

At least 91 records · Page 5Linked to original sources
PubMed1993

Randomized field trial to determine the effects of oral selenium supplementation on milk production and reproductive performance of Holstein heifers.

A field trial was conducted to measure differences in performance between selenium-supplemented and nonsupplemented heifers on a 1,200-cow California dairy. One hundred seventeen 19- to 27-month-old Holstein heifers were randomly assigned to treatment (n = 59) and control (n = 58) groups. A federally approved, commercially available, sustained-release intraruminal selenium bolus was administered to each heifer in the treatment group. Blood samples were taken from treated and control animals to assess selenium values before and after bolus administration and again after introduction to the milking ration. Production data were obtained from an on-farm computerized record system for each heifer during her first lactation. Mean blood selenium concentrations in treated heifers were higher than those in control heifers from posttreatment day 30 until after calving. Data analyzed in midlactation and late lactation indicated no significant differences between treated and control groups in somatic cell count, days not pregnant, total milk produced, or times bred.

Administration, Oral↗
PubMed1993

Congenital Neospora infection in calves born from cows that had previously aborted Neospora-infected fetuses: four cases (1990-1992).

Four dairy cows that had been successfully rebred following fetal Neospora infection and abortion were identified from 2 drylot dairies. All 4 cows had uncomplicated pregnancies with the birth of 5 full-term calves. The calves all had high precolostral serum IgG antibodies. The precolostral antibodies to Neospora sp as determined by indirect fluorescent antibody test ranged from 5,120 to 20,480, compared with maternal serum and colostral antibody titers from 320 to 1,280. Two calves had mild neurologic limb deficits. Three calves had mild nonsuppurative encephalomyelitis and Neospora organisms were found in the CNS of 3 calves. Findings indicate that repeat transplacental Neospora infections occur in cows. Additionally, calves born from cows with a history of Neospora fetal infection and abortion may have congenital Neospora infections and/or neurologic dysfunctions at birth. The Neospora indirect fluorescent antibody test appears to be a useful antemortem test for detection of calves exposed in utero to Neospora organisms.

Abortion, Veterinary↗
PubMed1993

Prediction of visual function in eyes with mild to moderate posterior pole residua of retinopathy of prematurity. Cryotherapy for Retinopathy of Prematurity Cooperative Group.

OBJECTIVE: The Multicenter Trial of Cryotherapy for Retinopathy of Prematurity (CRYO-ROP) assigned eyes with macular heterotopia to the "favorable" outcome category and eyes with retinal fold involving the macula to the "unfavorable" outcome category. This binary assignment did not agree well with measured visual acuity outcome. We tested the hypothesis that rating structural outcome on a continuum from less to more severe would improve prediction of visual acuity in eyes with macular heterotopia or retinal fold. DESIGN: Fundus photographs of the 69 eyes in the CRYO-ROP trial that had macular heterotopia (n = 55) or retinal fold (n = 14) at the 1-year follow-up were analyzed for severity of macular heterotopia, macular elevation, and pigmentary disturbances. Each physician author estimated each eye's predicted Snellen acuity, based on the photographic findings and clinical expertise. These results were compared with the grating acuity obtained at ages 1 and 3 1/2 years with the Teller Acuity Card procedure and with letter acuity obtained at age 3 1/2 years with the crowded HOTV test. PATIENTS: The 69 eyes were from 59 patients in the randomized portion of the CRYO-ROP trial. RESULTS: Although eyes with retinal fold tended to have greater visual impairment than eyes with macular heterotopia, there was a wide variation in acuity in both groups, and physicians were unable to predict visual acuity from retinal appearance. CONCLUSION: The physician cannot reliably predict either grating acuity or letter acuity in eyes with macular heterotopia or macular fold due to retinopathy of prematurity. There is no substitute for periodic visual acuity testing in these eyes.

Child, Preschool↗
PubMed1993

The role of T-helper lymphocytes in priming for experimental autoimmune glomerulonephritis in the BN rat.

In our model of experimental autoimmune glomerulonephritis (EAG), BN rats given a single IM injection of homologous glomerular basement membrane (GBM) in FCA develop anti-GBM autoantibodies with focal glomerulonephritis. To investigate the role of lymphocytes in the induction of EAG, we examined the effects of antigen rechallenge and of adoptive cell transfer from donors with nephritis to naive recipients. Groups of animals were rechallenged with GBM in FCA following either low (non-nephritogenic) doses of GBM, or following resolution of EAG. This resulted in an enhanced anti-GBM antibody response in both groups, suggesting the presence of GBM specific T or B memory cells. To investigate this possibility, spleen cells from animals with EAG were transferred into lightly irradiated recipients. There was no significant rise in anti-GBM antibody levels after transfer. However, subsequent challenge with GBM in FCA resulted in an enhanced anti-GBM antibody response by 2 weeks when compared with recipients of normal spleen cells. Cells capable of priming for EAG developed by week 4 after immunization of donors and persisted in the recipients for at least 24 weeks. To investigate which cell type was responsible for this effect, we depleted or positively selected donor spleen cells prior to transfer, using Dynabeads coated with monoclonal antibodies to Th or B lymphocytes. Depletion of Th cells, but not B cells, reduced the enhanced anti-GBM antibody response of recipients challenged with GBM in FCA. Positively selected Th cells, but not B cells, resulted in an enhanced anti-GBM antibody response similar to that in positive controls. These results demonstrate the presence of immunological memory for the autoantigen and show that priming for EAG is mediated by Th lymphocytes.

Animals↗
PubMed1993

The feasibility of smoking bans on psychiatric units.

We conducted a prospective study of a smoking ban on a general inpatient psychiatry service in response to staff concerns about the feasibility of a proposed hospital-wide ban. Demographic information, smoking history, and DSM III-R diagnoses were obtained for consecutively admitted patients during two study conditions: smoking and nonsmoking. A log of p.r.n. medication, seclusion, restraint, elopement, incident reports, and smoking-related discharges was kept for each patient. Chi-square analysis of 232 patients for whom demographic, smoking, diagnostic, and log data were complete showed no significant differences between study conditions for demographic or diagnostic variables. Two-tailed t-test analysis of the log data for these 232 patients showed no significant difference in disruptive incidents during smoking and nonsmoking conditions (p = 0.183). Fifty staff members answered pre- and post-ban questionnaires. Paired t-test analysis demonstrated a significant change in staff attitude toward supporting the ban. These data indicate that smoking can be stopped on inpatient psychiatry units without increases in unit disruption or adverse effects on staff morale.

Adult↗
PubMed1993

Professional constructions of a 'lay' illness: 'nerves' in a rural 'coloured' community in South Africa.

As part of a larger study, medical practitioners working in Mamre, a 'coloured' village close to Cape Town, South Africa, were interviewed concerning their use of the term 'nerves' in interaction with their patients. Contrary to the initial perception of researchers and some clinicians, the term is not simply a folk category. It does, however, represent a medium through which psychosocial issues are discussed in the clinical encounter. Differences in the usage of the term by different practitioners seemed to indicate different attitudes towards patient care. The data are presented and discussed in the context of debates concerning the development of more accessible and responsive health services in a future South Africa, and the information gleaned has implications for future training of clinicians.

Black or African American↗
PubMed1993

Controlled comparison of the BACTEC high-blood-volume fungal medium, BACTEC Plus 26 aerobic blood culture bottle, and 10-milliliter isolator blood culture system for detection of fungemia and bacteremia.

The BACTEC high-blood-volume fungal medium (HBV-FM) (Becton Dickinson Diagnostic Instrument Systems, Sparks, Md.) was compared with the Isolator (IS) tube and the BACTEC Plus 26 (BP26) blood culture bottle for the ability to recover fungi from the blood of adult patients suspected of having fungemia. A total of 6,836 blood culture sets that fulfilled criteria for inclusion in the study were received. Three separate comparisons were performed: 4,907 HBV-FM versus IS, 4,886 BP26 versus HBV-FM, and 4,949 BP26 versus IS. For the HBV-FM versus IS comparison, 218 isolates were recovered: 125 (57.3%) were bacteria and 93 (42.7%) were fungi. HBV-FM was comparable to IS for recovery of yeasts, but IS was superior for recovery of Histoplasma capsulatum (25 versus 0 isolates recovered [P < 0.001]). Growth of Torulopsis glabrata was detected earlier (P < 0.05) in HBV-FM bottles. For the BP26 versus HBV-FM comparison, 229 isolates were recovered: 161 (70.3%) were bacteria, and 68 (29.7%) were fungi. HBV-FM was superior for recovery of T. glabrata (P < 0.025) and all fungi combined (P < 0.025). There were no statistically significant differences in the speed of detection of microbial growth. For the BP26 versus IS comparison, 251 isolates were recovered: 165 (65.7%) were bacteria, and 86 (34.2%) were fungi. IS was superior for recovery of H. capsulatum (P < 0.001), T. glabrata (P < 0.05), and fungi other than H. capsulatum (P < 0.025). BP26 was superior for recovery of all bacteria combined (P < 0.001) and viridans group streptococci (P < 0.01). Growth of T. glabrata (P < 0.05) was detected earlier in IS tubes. Growth of Staphylococcus aureus (P < 0.01), viridans group streptococci (P < 0.01), Pseudomonas aeruginosa (P < 0.05), and all microorganisms combined (P < 0.05) was detected earlier in BP26 bottles. For yeast, 57 of 59 (96.6%), 79 of 80 (98.7%), and 64 of 67(95.5%) were recovered from BP26 bottles, HBV-FM bottles, and IS tubes, respectively, by day 14; for H. capsulatum, 14 of 36 (38%) isolates were recovered from IS tubes by day 14. Mean times of recovery were similar for BACTEC bottles and IS. We conclude that (i) for recovery of fungi from blood cultures, HBV-FM is equivalent to IS (with the exception of H. capsulatum); (ii) for recovery of bacteria, BP26 is superior to IS; (iii) BP26 bottles are inferior to both HBV-FM bottles and IS tubes for recovery of T. glabrata; and (iv) HBV-FM bottles must be paired with another blood culture bottle or system to optimize detection of bacteremia.

Aerobiosis↗
PubMed1993

Comparison of percutaneous venous catheters and teflon catheters for intravenous therapy in neonates.

The purpose of this study was to compare the average duration of catheterization of percutaneous venous catheters (PVCs) with Teflon catheters placed in peripheral veins of neonates, and to describe the incidence of mechanical or infectious complications associated with their use. The sample consisted of twelve subjects with a total of 52 catheters--17 PVCs and 35 Teflon catheters. The results of the study indicated both a significant increase in the duration of catheterization (p = .001) and a significant reduction in the incidence of complications (p = .004) when PVCs were used. The mean duration of catheterization for PVCs was 178.6 hours and for Teflon catheters 41.9 hours. Although 80.8 percent of all the neonates studied suffered some complication leading to early catheter removal, such complications were observed most frequently with Teflon catheters (91 versus 59 percent of PVCs). However, the one subject who experienced the complication of catheter-related sepsis did have a PVC in situ for 313.5 hours. For this sample of neonates, the PVC was the most efficacious mode of IV therapy.

Catheterization, Peripheral↗
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↗