Biomedical subjects

M Bridget Zimmerman

Publications and source records attributed to M Bridget Zimmerman.

45 records · Page 3Linked to original sources

PubMed2003

Hepatic iron overload in blacks and whites: a comparative autopsy study.

OBJECTIVE: Genetic susceptibility to iron loading is an important factor in the development of iron overload in Africans. This suggests that persons of African descent may be at risk to develop iron overload with its attendant complications, but relatively little is known about hepatic iron overload among blacks. The aim of this study was to compare the prevalence, histological features, and clinical correlates of hepatic iron overload in a group of autopsied black and white veterans. METHODS: Hepatic iron concentrations (HIC) were determined on liver tissue from autopsies performed at the John Cochran Veterans Affairs Medical Center during the period 1993 to 1996. Clinical information was obtained from autopsy protocols. Sections from livers in which the HIC exceeded the upper limit of normal were examined histologically. RESULTS: Of 256 specimens, 99 were from blacks (39%), whereas 157 were from whites (61%). Thirty-one blacks (31%) had an elevated HIC versus 44 whites (28%) (ns). In the majority of these cases (18 blacks, 30 whites), the HIC was less than twice the upper limit of normal. Nine of 15 subjects with an HIC greater than twice the upper limit of normal and no evident cause of secondary iron overload were black. CONCLUSIONS: The prevalence of mild-to-moderate hepatic iron overload was similar in this group of black and white veterans. Because of the inherent limitations of autopsy studies, prospective assessment of iron stores in healthy blacks is needed to determine more accurately the prevalence and clinical significance of iron overload in this population.

Adult↗

PubMed2002

Intranasal mupirocin to prevent postoperative Staphylococcus aureus infections.

BACKGROUND: Patients with nasal carriage of Staphylococcus aureus have an increased risk of surgical-site infections caused by that organism. Treatment with mupirocin ointment can reduce the rate of nasal carriage and may prevent postoperative S. aureus infections. METHODS: We conducted a randomized, double-blind, placebo-controlled trial to determine whether intranasal treatment with mupirocin reduces the rate of S. aureus infections at surgical sites and prevents other nosocomial infections. RESULTS: Of 4030 enrolled patients who underwent general, gynecologic, neurologic, or cardiothoracic surgery, 3864 were included in the intention-to-treat analysis. Overall, 2.3 percent of mupirocin recipients and 2.4 percent of placebo recipients had S. aureus infections at surgical sites. Of the 891 patients (23.1 percent of the 3864 who completed the study) who had S. aureus in their anterior nares, 444 received mupirocin and 447 received placebo. Among the patients with nasal carriage of S. aureus, 4.0 percent of those who received mupirocin had nosocomial S. aureus infections, as compared with 7.7 percent of those who received placebo (odds ratio for infection, 0.49; 95 percent confidence interval, 0.25 to 0.92; P=0.02). CONCLUSIONS: Prophylactic intranasal application of mupirocin did not significantly reduce the rate of S. aureus surgical-site infections overall, but it did significantly decrease the rate of all nosocomial S. aureus infections among the patients who were S. aureus carriers.

Administration, Intranasal↗

PubMed2002

Hematologic abnormalities associated with various types of retinal vein occlusion.

BACKGROUND: The objective of this study was two-fold: (1) to investigate hematologic abnormalities associated with various types of retinal vein occlusion (RVO) and comparison of their prevalence among those various types of RVO; (2) to review the conflicting literature on the subject, to place the information in perspective. METHODS: In patients with various types of RVO seen in our clinic since 1973, we conducted planned prospective studies on the prevalence of: (1) routine hematologic tests (535 patients) and (2) certain special hematologic parameters (platelet aggregation, antithrombin III, and proportional, variant(2) globulin in 110, 81 and 91 patients, respectively). Patients were categorized into six types of RVO, based on defined criteria: non-ischemic and ischemic central RVO (CRVO), non-ischemic and ischemic hemi-CRVO (HCRVO), and major and macular branch RVO (BRVO). The patients had a detailed ophthalmic, systemic and hematologic evaluation. The data were abstracted and analyzed retrospectively from the detailed information originally collected prospectively in the patients' records. For data analysis, patients were divided into young, middle-aged and elderly. Observed prevalence rates of hematologic abnormalities were estimated. Logistic regression, adjusting for age and gender, was used to compare the observed prevalence of hematologic abnormalities among the various types of RVO. RESULTS: No generalizations about the prevalence of hematologic disorders in all six types of RVO are possible. Ischemic CRVO showed a significantly higher prevalence of abnormal hematocrit ( P=0.044), hemoglobin ( P=0.018), and blood urea nitrogen ( P=0.025) than non-ischemic CRVO, while a significantly higher prevalence of abnormal antinuclear antibody (ANA; P=0.049) was seen in non-ischemic CRVO than in ischemic CRVO. There was a significant ( P=0.011) difference in the prevalence of abnormal uric acid among the three main RVO groups (CRVO, HCRVO, BRVO), highest in BRVO and lowest in HCRVO. There was a higher prevalence of abnormal glucose ( P=0.069) and ANA ( P=0.071) in CRVO+HCRVO than in BRVO. Results of special hematologic studies are given. CONCLUSIONS: Our study showed that a variety of hematologic abnormalities may be seen in association with different types of RVO, and any generalization about these disorders applied to all RVO patients may be misleading. The evidence of our study and in the literature indicates that there is no good reason why all patients with RVO should be subjected to extensive, expensive, special hematologic and hypercoagulability investigations, unless, of course, there is some clear indication; the routine, inexpensive hematologic evaluation is usually sufficient for RVO patients. Treatment with anticoagulants or platelet anti-aggregating agents may adversely influence the visual outcome, without any evidence of protective or beneficial effect.

Adolescent↗

PubMed2002

Variations in the myocilin gene in patients with open-angle glaucoma.

OBJECTIVE: To determine the prevalence and associated phenotype of myocilin (MYOC) coding sequence variations and a specific promoter polymorphism (MYOC.mt1) in patients with glaucoma and glaucoma suspects. METHODS: A consecutive, unselected series of 779 patients (652 with open-angle glaucoma and 127 glaucoma suspects) were recruited from a university medical center and clinically characterized. The coding sequences of the MYOC gene and the MYOC.mt1 locus in the promoter region were screened for sequence variations. We determined the prevalence of MYOC coding sequence mutations and the MYOC.mt1 promoter polymorphism. We also compared the clinical features of individuals with and without mutations and the MYOC.mt1 promoter polymorphism. RESULTS: Plausible disease-causing sequence variations (DCVs) in the MYOC gene were found in 3.0% of the entire group. Such variations were found in patients with most forms of open-angle glaucoma studied. Patients with primary open-angle glaucoma (POAG) who harbored coding sequence DCVs were clinically similar to patients without them. Patients who harbored the rarer allele of the MYOC.mt1 promoter polymorphism were no different in any measure of disease severity from those who harbored the more common allele. CONCLUSIONS: MYOC DCVs were found in approximately 3% of patients with glaucoma and glaucoma suspects. The 2 alleles of the MYOC.mt1 promoter polymorphism were equally distributed among patients with POAG and healthy control subjects. Patients with POAG who harbored the rarer allele of the MYOC.mt1 promoter polymorphism were no different from those with the more common variant in any measure of disease severity. CLINICAL RELEVANCE: Testing for the MYOC.mt1 promoter polymorphism appears to be of no value in the evaluation of patients with glaucoma.

Adult↗

PubMed2002

A case-control comparison of the clinical characteristics of glaucoma and ocular hypertensive patients with and without the myocilin Gln368Stop mutation.

PURPOSE: To determine whether primary open-angle glaucoma (POAG) and ocular hypertensive (OHT) patients who harbor the myocilin Gln368Stop mutation differ in phenotype or clinical course from patients without the mutation. DESIGN: Case-control study. METHODS: A retrospective case-control study compared all known POAG patients (n = 18) and OHT patients (n = 4) harboring the Gln368Stop mutation evaluated by the University of Iowa Glaucoma Service with control patients from the same population. Patients and control subjects were matched for diagnosis, age, sex, and race and were compared for phenotype and clinical course. RESULTS: Mean age of disease onset and mean peak intraocular pressures (IOPs) of cases were similar to those reported by other studies. There was no statistically significant difference between cases and controls for the following variables: age at onset, peak intraocular pressure, Snellen visual acuity, number of medications, Humphrey visual field (HVF) mean deviation, HVF pattern deviation, number of filtering surgeries performed, time intervals from diagnosis to argon laser trabeculoplasty (ALT), diagnosis to first filtering surgery, ALT to first filtering surgery, and percent change in IOP after ALT and after first filtering surgery. CONCLUSIONS: There is no statistically significant difference between the onset and clinical course of POAG and OHT caused by the Gln368Stop mutation and POAG and OHT not associated with the mutation.

Adult↗

PubMed2002

Rate and pattern of visual field decline in primary open-angle glaucoma.

PURPOSE: To study the rate and pattern of visual field decline in primary open-angle glaucoma. DESIGN: Retrospective observational case series. PARTICIPANTS: Forty eyes of 40 patients with primary open-angle glaucoma that were followed longitudinally with serial Goldmann visual fields for a minimum period of 8 years in an academic institution. Eyes with any other ocular disease except for mild cataract were excluded. METHODS: Visual fields obtained with worse than 20/50 Snellen visual acuity from cataract were excluded from analysis. In the remainder (671 Goldmann visual fields), the I4e isopter was quantified manually using a grid template previously described by Esterman. The visual field was divided into central and peripheral, superior and inferior, and nasal and temporal regions, all centered at the blind spot. The rate of visual field decline was estimated for each visual field region (including the four quadrants: superonasal [SN], superotemporal [ST], inferotemporal [IT], and inferonasal [IN]) using linear regression. Asymmetry of visual field progression was determined by comparing the rates of progression among the four quadrants. Pertinent clinical factors were evaluated for association with the asymmetry of visual field progression. MAIN OUTCOME MEASURES: Rates of visual field decline for the entire visual field and each region. Long-term clinical outcome measures, including visual acuity, cataract and cup-to-disc ratio progression, intraocular pressures, and medical and surgical interventions were also studied. RESULTS: The rate of visual field change was -1.3% per year for the entire visual field. The rates of visual field section change (in % per year) were -1.3 (central), -1.4 (peripheral), -1.5 (superior), -1.2 (inferior), -1.4 (nasal), -1.2 (temporal), -1.8 (SN), -1.3 (IT), -1.2 (IN), and -1.1 (ST). About half the patients showed symmetric visual field decline, whereas others showed a more asymmetric pattern. Asymmetric visual field progression was associated with the presence of disc hemorrhage, overall rate of visual field progression, and surgical intervention for glaucoma. CONCLUSIONS: In this group of selected patients with primary open-angle glaucoma with a long-term follow-up, all sections of the visual field declined over time. Disc hemorrhage was associated with more asymmetric visual field progression, implicating focal damage to the optic disc.

Adult↗

PubMed2002

Body weight is a predictor of biphasic shock success for low energy transthoracic defibrillation.

BACKGROUND: Transthoracic impedance and current flow are determinants of defibrillation success with monophasic shocks. Whether transthoracic impedance, either independently or via its association with body weight, is a determinant of biphasic waveform shock success has not been determined. METHODS AND RESULTS: We studied 22 swine, weighing 18-41 kg. After 15 s of ventricular fibrillation, each pig received transthoracic truncated exponential biphasic shocks (5/5 ms), 70-360 J. Shock success was strongly associated individually with body weight, leading-edge transthoracic impedance and current at low energy levels (70 and 100 J, all P<0.001). Multiple logistic regression analysis showed a significant association of body weight with shock success after adjusting for the effect of leading-edge impedance (odds ratio of success for 1 kg decrease in weight at 70 J was 1.29, 95% CI: 1.05-1.59, P=0.02; and at 100 J was 1.30, 95% CI: 1.14-1.49, P<0.0001). The same result was observed after adjusting for the effect of leading-edge current. At 150 J or higher energy levels, no significant association was observed. CONCLUSIONS: Body weight is a determinant of shock success with biphasic waveforms at low energy levels in this swine model.

Animals↗

PubMed2002

Factors that predict low hematocrit levels in the postpartum patient after vaginal delivery.

OBJECTIVE: The purpose of this study was to provide a viable alternative to routine postpartum hematocrit measurement, by a determination of the clinical risk factors that identify patients with anemia and an examination of the resulting cost savings. STUDY DESIGN: In this retrospective review, cases (postpartum hematocrit level, <26%; subgroup hematocrit level, <23%) and control subjects were culled from the records of all vaginal deliveries from February 1997 to July 1998. Charts were reviewed for demographic characteristics, medical history, nursing assessments, and postpartum hematocrit measurements. Logistic regression modeling determined the best set of risk factors for the identification of low postpartum hematocrit levels. RESULTS: From 1484 vaginal deliveries, 117 of the women (8%) had postpartum hematocrit levels of <26%. Estimated blood loss of >500 mL, Hispanic ethnicity, dizziness, or third- or fourth-degree laceration were the factors that identified 82.9% of the women with hematocrit levels of <26% and identified 97.4% of the women with hematocrit levels of <23%. Only 39.3% of the women would have required postpartum hematocrit measurement to obtain these detection rates. CONCLUSION: Four risk factors (estimated blood loss of >500 mL, Hispanic ethnicity, dizziness, and third- or fourth-degree laceration) can safely determine the necessity of a postpartum hematocrit measurement.

Adult↗

PubMed2002

Diurnal cortisol variations and symptoms in patients with interstitial cystitis.

PURPOSE: Little attention has focused on systemic factors that may allow a state of chronic bladder inflammation to be established and maintained in interstitial cystitis cases. Abnormalities of the hypothalamic-pituitary-adrenal feedback system result in poorer regulation of the inflammatory response and are present in many chronic inflammatory and pain conditions, of which some have high co-morbidity with interstitial cystitis. MATERIALS AND METHODS: A total of 48 patients with interstitial cystitis and 35 healthy, age matched controls collected 24-hour urine samples and 3 days of salivary samples at 7 to 8 a.m., 4 to 5 p.m. and 8 to 9 p.m. for cortisol analysis. In addition, they completed a concurrent symptom questionnaire. Prospective symptom diaries also were completed in the month before sampling. RESULTS: Mean urinary or salivary cortisol did not differ in patients and controls. However, patients with interstitial cystitis and higher morning cortisol had significantly less pain and urgency, while those with higher urinary free cortisol reported less overall symptomatology (p <0.05). Relationships with morning cortisol were also observed when controlling for co-morbid conditions known to be affected by the hypothalamic-pituitary-adrenal axis, such as fibromyalgia, chronic fatigue and rheumatoid arthritis. Patients with morning cortisol less than 12.5 nmol./l. were 12.8 times more likely to report high urinary urgency than those with values above this cutoff. CONCLUSIONS: These findings imply that regulation of the hypothalamic-pituitary-adrenal axis may be associated with interstitial cystitis symptomatology and there may be different diurnal hypothalamic-pituitary-adrenal patterns in patients with interstitial cystitis who do and do not have co-morbid conditions. These findings may have treatment implications for patients with interstitial cystitis who have early morning cortisol deficiencies.

Adult↗