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Biomedical subjects

E Fisher

Publications and source records attributed to E Fisher.

At least 37 records · Page 2Linked to original sources
PubMed2000

Effects of glucose on matrix metalloproteinase and plasmin activities in mesangial cells: possible role in diabetic nephropathy.

Diabetic nephropathy is characterized by an accumulation of mesangium matrix that correlates well with the loss of kidney function. High glucose concentration is known to increase the synthesis of many matrix components. Recently, we have shown that degradation of matrix also decreases in diabetes. The major enzymes responsible for matrix degradation are the matrix metalloproteinases. The physiology of these enzymes is complex and their activity is tightly regulated at many levels. At the transcriptional level matrix metalloproteinase (MMP) expression is increased by protein kinase C (PKC) agonists, and some growth factors. In contrast transforming growth factor (TGF)-beta can decrease MMP expression. Once synthesized, MMPs are secreted as inactive pro-enzymes that are activated by other MMPs or plasmin. To effect this, plasmin must be liberated from plasminogen in the pericellular environment. In turn, activated MMPs can be inhibited by binding to specific inhibitors known as tissue inhibitor of metalloproteinases (TIMP). Cell culture and animal studies have shown that high glucose (HG) decreases expression of MMPs and increases expression of TIMPs. HG can also affect MMP activation by decreasing plasmin availability and reducing expression of a membrane-bound MMP called MT1-MMP. How HG induces these changes remains to be fully elucidated. One possibility is that HG can increase TGF-beta. which may in turn alter MMP promoter activity: this area is currently being studied in our laboratory.

Animals↗
PubMed2000

Decision-making and outcomes of prolonged ICU stays in seriously ill patients.

BACKGROUND: Despite concern about the high costs and the uncertain benefit of prolonged treatment in the intensive care unit (ICU), there has been little research examining decision-making and outcomes for patients with prolonged ICU stays. OBJECTIVES: To evaluate decision-making and outcomes for seriously ill patients with an ICU stay of at least 14 days. DESIGN: A prospective cohort study. SETTING: Five teaching hospitals. PARTICIPANTS: Seriously ill patients enrolled in the Study To Understand Prognoses and Preferences for Risks and Outcomes of Treatments (SUPPORT). MEASUREMENT: Patients, their surrogate decision-makers, and their physicians were interviewed about prognosis, communication, and goals of medical care. Based on age, diagnoses, comorbid illnesses, and acute physiology data, the SUPPORT Prognostic Model provided estimates of 6-month survival on study days 1, 3, 7, and 14. Hospital costs were estimated from hospital billing data. RESULTS: Of the 9105 patients enrolled in SUPPORT, 1494 (16%) had ICU stays of 14 days or longer. The median length of stay in an ICU was 4 days for the entire SUPPORT cohort and 35 days for patients who were treated in an ICU for 14 days or longer. Median hospital costs were $76,501 for patients who had ICU stays 14 days or longer and $10,916 for patients who did not have long ICU stays. Fifty-five percent of patients with long ICU stays had died by 6 months, and an additional 19% had substantial functional impairment. Among patients with ICU stays of at least 14 days, only 20% had estimates of 6-month survival that fell below 10% at any time during their hospitalization. For patients with long ICU stays, the mean predicted probability of 6-month survival was 0.46 on study Day 3 and 0.47 on study Day 14. Fewer than 40% of patients (or their surrogates) reported that their physicians had talked with them about their prognoses or preferences for life-sustaining treatment. Among the patients who preferred a palliative approach to care, only 29% thought that their care was consistent with that aim. Those who discussed their preferences for care with a physician were 1.9 times more likely to believe that treatment was in accord with their preferences for palliation (95% CI, 1.4-2.5) CONCLUSIONS: Prolonged ICU stays were expensive and were often followed by death or disability. Patients reported low rates of discussions with their physicians about their prognoses and preferences for life-sustaining treatments. Many preferred that care focus on palliation and believed that care was inconsistent with their preferences. Patients were more likely to receive care consistent with their preferences if they had discussed their care preferences with their physicians.

Activities of Daily Living↗
PubMed2000

Geographic variation in hospice use prior to death.

OBJECTIVES: To examine national variation in use of the Medicare hospice benefit by older individuals before their death, and to identify individual characteristics and local market factors associated with hospice use. DESIGN: Retrospective analysis of Medicare administrative data. SETTING: Hospice care. PARTICIPANTS: Older Medicare enrollees who died in 1996. MEASUREMENTS: Rate of hospice use per 1,000 older Medicare beneficiary deaths. RESULTS: Overall, 155 of every 1,000 older Medicare beneficiaries who die use hospice before death. This rate is significantly higher among younger older persons (P < .001), non-blacks (P < .001), persons living in wealthier areas (P < .001), and persons in urban areas (P < .001). Areas with a higher proportion of non-cancer diagnoses among hospice users have higher rates of hospice use for both cancer and non-cancer reasons than areas with a majority of hospice users having cancer diagnoses (P < .001). Hospice use is higher in areas with fewer hospital beds per capita (P < .001), areas with lower in-hospital death rates (P < .001), and areas with higher HMO enrollment (P < .001). Rates of hospice use are also positively related to average reimbursements for health care (P < .001) and to physicians per capita (P < .001). In the largest metropolitan statistical areas (MSAs), rates of hospice use vary more than 11-fold from a low of 35.15 (Portland, ME) to a high of 397.2 per 1,000 deaths (Ft. Lauderdale, FL). CONCLUSIONS: The wide variation in hospice use suggests that there is great potential to increase the number of users of the Medicare hospice benefit.

Age Distribution↗
PubMed2000

Type C botulism in dairy cattle from feed contaminated with a dead cat.

Four hundred twenty-seven of 441 adult Holstein dairy cattle from a 1,200-cow dairy died over a 1-week period during early spring 1998. Affected animals were from 4 late lactation pens, one of which included the bull string. Signs included weakness, recumbency, watery diarrhea, and death. Eighty animals from the 4 pens were dead approximately 8 hours after the first ill cows were noted. Affected cows would collapse on stimulation and extend all 4 limbs with moderate rigidity. Several lacked lingual tonus and had abdominal breathing patterns. The animals had been fed a load of total mixed ration that included a rotten bale of oat hay containing a dead cat. No common toxicants were identified, and pathologic examination revealed no consistent lesions. Testing of tissue from the cat carcass found in the feed sample using mouse protection bioassay identified the presence of type C botulinum toxin. Samples of feed, tissue from affected animals, cat tissue from feed, milk, and serum were also tested using an enzyme-linked immunosorbent assay (ELISA) specific for type C botulinum. Two samples of rumen contents were tested and found to be positive for botulism by ELISA, and 1 of 3 liver samples had a weak positive finding. No botulinum toxin was found in milk or sera using the ELISA.

Animal Feed↗
PubMed2000

Brain atrophy in relapsing multiple sclerosis: relationship to relapses, EDSS, and treatment with interferon beta-1a.

Brain atrophy is a relevant surrogate marker of the disease process in multiple sclerosis (MS) because it represents the net effect of various pathological processes leading to brain tissue loss. There are various approaches to quantifying central nervous system atrophy in MS. We have focused on a normalized measure of whole brain atrophy, the brain parenchymal fraction (BPF). BPF is defined as the brain parenchymal volume, divided by the volume within the surface of the brain. We applied this method to an MRI data set generated during a phase III clinical trial of interferon beta-1a (AVONEX). The purpose of the current study is to further explore clinical and MRI correlates of the BPF, particularly as they relate to relapse rate and Kurtzke's Expanded Disability Status Score (EDSS); and to further explore the therapeutic effects observed in interferon beta-1a recipients. Of all demographic and disease measures in the clinical trial data base, T2 lesion volume most closely correlated with BPF in cross sectional studies, and was the baseline factor most closely correlated with progressive brain atrophy in the subsequent 2 years. We also observed that change in T2 lesion volume was the disease measure most closely correlated with change in BPF during 2 years of observation. Of interest, relapse number and EDSS change during 2 years were only weakly correlated with BPF change during the same period. Disability progression, defined as sustained worsening of at least 1.0 EDSS points from baseline, persisting at least 6 months, was associated with significantly greater brain atrophy progression. We observed a therapeutic effect of interferon beta-1a in the second year of the clinical trial, and this beneficial effect was not accounted for by change in gadolinium enhanced lesion volume, or by corticosteroid medication within 40 days of the final MRI scan. The BPF is an informative surrogate marker for destructive pathological processes in relaping MS patients, and is useful in demonstrating treatment effects in controlled clinical trials. The significance of progressive brain atrophy during relapsing MS will be assessed by measuring clinical and MRI changes in prospective follow up studies.

Adjuvants, Immunologic↗
PubMed2000

Relationship between brain atrophy and disability: an 8-year follow-up study of multiple sclerosis patients.

Brain atrophy measurement can provide an estimate of the amount of tissue destruction due to the pathologic processes in multiple sclerosis. The potential usefulness of atrophy as a marker of disease progression depends upon the concurrent and predictive relationships between atrophy and disability. A follow-up study was performed to measure atrophy and disability scores in patients from the Multiple Sclerosis Collaborative Research Group's phase III trial of IFNbeta-1a (Avonex) in relapsing- remitting multiple sclerosis. New data were obtained on 160 out of 172 eligible patients from the original trial were enrolled in the follow-up study approximately 8 years after randomization. The follow-up visit consisted of several tests and questionnaires including a clinical exam to determine Expanded Disability Status Score (EDSS) and Multiple Sclerosis Functional Composite (MSFC), and a magnetic resonance imaging exam to calculate the brain parenchymal fraction. Brain parenchymal fraction was correlated with both EDSS and MSFC at each of the four time points for which data were available (baseline 1, 2 and 8 years). Furthermore, the change in BPF was correlated with the changes in disability scores from the end of the phase III trial to the follow-up exam. These data suggest that brain atrophy may be a useful and clinically relevant marker of disease progression in relapsing--remitting MS.

Adjuvants, Immunologic↗
PubMed2000

HIV-associated lipodystrophy syndrome.

Highly active antiretroviral therapy (HAART) for human immunodeficiency virus-1 (HIV-1) and prophylactic therapy for opportunistic infections have increased survival. Adverse effects of HAART include lipid profile alterations, diabetes mellitus, and fat redistribution. These metabolic and physical changes are called the HIV-associated lipodystrophy syndrome. A link to protease inhibitors has been suggested, and more recently to nucleoside reverse transcriptase inhibitors and factors related to duration of HIV-1 infection itself.

Anti-HIV Agents↗
PubMed1999

Use of the brain parenchymal fraction to measure whole brain atrophy in relapsing-remitting MS. Multiple Sclerosis Collaborative Research Group.

BACKGROUND: Episodic inflammation in the CNS during the early stages of MS results in progressive disability years later, presumably due to myelin and axonal injury. MRI demonstrates ongoing disease activity during the early disease stage, even in some patients who are stable clinically. The optimal MRI measure for the destructive pathologic process is uncertain, however. METHODS: In this post-hoc study, MRI scans were analyzed from patients with relapsing MS participating in a placebo-controlled trial of interferon beta-1a. The brain parenchymal fraction, defined as the ratio of brain parenchymal volume to the total volume within the brain surface contour, was used to measure whole brain atrophy. The relationship between disease features and brain atrophy and effect of interferon beta-1a were determined. RESULTS: MS patients had significant brain atrophy that worsened during each of 2 years of observation. In many patients, brain atrophy worsened without clinical disease activity. Baseline clinical and MRI abnormalities were not strongly related to the rate of brain atrophy during the subsequent 2 years. Treatment with interferon beta-1a resulted in a reduction in brain atrophy progression during the second year of the clinical trial. CONCLUSIONS: Patients with relapsing-remitting MS have measurable amounts of whole brain atrophy that worsens yearly, in most cases without clinical manifestations. The brain parenchymal fraction is a marker for destructive pathologic processes ongoing in relapsing MS patients, and appears useful in demonstrating treatment effects in controlled clinical trials.

Adjuvants, Immunologic↗
PubMed1999

Periictal diffusion-weighted imaging in a case of lesional epilepsy.

PURPOSE: Diffusion-weighted MR imaging (DWI) has been used for the early diagnosis of acute ischemic lesions in humans and in animal models of focal status epilepticus. We hypothesized that DWI may be a sensitive, noninvasive tool for the localization of the epileptogenic area during the periictal period. METHODS: A periictal DWI study was performed on a 35-year-old patient during focal status epilepticus with repetitive prolonged focal motor seizures originating from a lesion in the right frontal lobe. DWI results were analyzed visually and by calculating apparent diffusion coefficient (ADC) maps. RESULTS: On DWI, a single area of signal increase (decrease in ADC) was found in the region of focal electrocorticographic seizures that was mapped intraoperatively. CONCLUSIONS: Ictal/postictal DWI may be a useful technique for seizure localization in patients with lesional epilepsy.

Adult↗
PubMed1999

Mutations in the apolipoprotein (apo) B-100 receptor-binding region: detection of apo B-100 (Arg3500-->Trp) associated with two new haplotypes and evidence that apo B-100 (Glu3405-->Gln) diminishes receptor-mediated uptake of LDL.

BACKGROUND: Ligand-defective apolipoprotein (apo) B-100 is a major cause of hypercholesterolemia. For many years, apo B-100 (Arg3500-->Gln) has been the only mutation known to cause ligand-defective apo B-100. METHODS: Using temperature gradient gel electrophoresis, we screened 297 unrelated individuals with LDL-cholesterol >1.55 g/L and triglycerides <2.0 g/L for sequence variants of the putative LDL receptor-binding domain of apo B-100. RESULTS: We found apo B-100 (Arg3500-->Gln) in 21 individuals (7.1%). When extrapolated to the general population, this corresponds to the highest prevalence of apo B-100 (Arg3500-->Gln) reported to date. Furthermore, we identified three unrelated carriers (1%) of a silent substitution (CTG-->CTA) affecting the codon for leucine3350, four carriers (1.3%) of apo B-100 (Glu3405-->Gln), and two subjects (0.7%) with apo B-100 (Arg3500-->Trp). apo B-100 (Arg3500-->Trp) was assigned to two different, previously unknown haplotypes. The binding, uptake, and degradation of apo B-100 (Arg3500-->Trp) was lower than that of normal LDL, but higher than with apo B-100 (Arg3500-->Gln), implying that the substitution of Trp3500 for Arg may cause less severe reduction of binding than the substitution of Gln. LDL from individuals heterozygous for apo B-100 (Glu3405-->Gln) bound to LDL receptors at the same rate as normal LDL, but was taken up and degraded at significantly reduced rates, suggesting that domains of apo B-100 involved in binding and uptake do not completely overlap. CONCLUSIONS: In Germany, apo B-100 (Arg3500-->Gln) may be more frequent than previously assumed. Both apo B-100 (Arg3500-->Trp) and apo B-100 (Glu3405-->Gln) may contribute to the phenotype of ligand-defective LDL. These variants will be missed if screening is confined to apo B-100 (Arg3500-->Gln) only.

Adolescent↗
PubMed1999

Docetaxel (Taxotere) and estramustine versus mitoxantrone and prednisone for hormone-refractory prostate cancer: scientific basis and design of Southwest Oncology Group Study 9916.

Hormone-refractory prostate cancer is the terminal step in the natural history of prostate cancer. To date, no chemotherapeutic agents have been shown to impact clinical outcome at this stage. Recently, the Food and Drug Administration approved the combination of mitoxantrone and prednisone based solely on its superior palliative effects as compared to steroids alone in 2 randomized trials. Progress in biologically driven drug development has led to the identification of several estramustine-based regimens that, although based on single institution experience, appear to have at least a comparable but very promising level of activity in hormone-refractory prostate cancer patients. One such combination, estramustine plus docetaxel (Taxotere; Rhône-Poulenc Rorer, Collegeville, PA), is particularly attractive because of its convenient schedule and side effect profile. To objectively assess the therapeutic benefit of this combination, the Southwest Oncology Group is initiating a randomized phase III trial comparing estramustine and docetaxel with the standard arm of mitoxantrone and prednisone using time to progression and survival as the primary end points. Secondary end points will include toxicity profiles, assessments of quality of life parameters, and magnitude of decline of prostate-specific antigen levels between the two treatment arms.

Adenocarcinoma↗
PubMed1998

A randomized, placebo-controlled trial of the safety and efficacy of oral ganciclovir for prophylaxis of cytomegalovirus disease in HIV-infected individuals. Terry Beirn Community Programs for Clinical Research on AIDS.

OBJECTIVE: Evaluate safety and efficacy of oral ganciclovir (GCV) for preventing cytomegalovirus (CMV) disease in HIV-infected persons at high risk for CMV disease. DESIGN: Double-blind, placebo-controlled, randomized clinical trial in primary care clinics and private practice offices specializing in the care of people with HIV. Interventions were oral GCV (1000 mg three times/day) or placebo. Protocol amendment allowed switch to open-label oral GCV. Main outcome measures were confirmed CMV retinal or gastrointestinal mucosal disease, and death. The study enrolled 994 people co-infected with CMV and HIV, with at least one CD4 count recorded < 100 x 10(6) cells/l. RESULTS: At study completion (15 months median follow-up), CMV event rates in the oral GCV and control groups were 13.1 and 14.6 per 100 person years, respectively, a hazard ratio (HR) of 0.92 [95% confidence interval (CI), 0.65-1.27; P = 0.6]. At protocol amendment event rates were 12.7 and 15.0, respectively (HR, 0.85; 95% CI, 0.56-1.30; P = 0.45). At study completion, event rates for death were 26.6 and 32.0 (HR, 0.84; P = 0.09), and at protocol amendment were 18.9 and 19.6 (HR, 0.95; P = 0.78), respectively. At protocol amendment for the CMV endpoint, the oral GCV treatment effect was associated with baseline use of didanosine (ddI). For patients taking ddI at randomization, HR was 7.48 (P = 0.02). For patients not taking ddI, HR was 0.62 (P = 0.04). These HR were statistically different (P = 0.0006). CONCLUSIONS: In our study, 3 g/day oral GCV did not significantly reduce CMV disease incidence, but there was a suggestion of a death-rate reduction. Furthermore, results suggest that oral GVC decreased risk of CMV disease in patients not prescribed ddI, and increased risk in those prescribed ddI. For the CMV endpoint, our study differs markedly from the only similar study, although for the death endpoint, a combined analysis of studies indicated significant reduction in death rate.

AIDS-Related Opportunistic Infections↗
PubMed1998

13-cis-retinoic acid or all-trans-retinoic acid plus interferon-alpha in recurrent cervical cancer: a Southwest Oncology Group phase II randomized trial.

PURPOSE: Preclinical and clinical data support the study of retinoids and interferon-alpha (IFN-alpha) in advanced squamous cell carcinoma of the uterine cervix (SCC). This phase II randomized trial of the Southwest Oncology Group sought to estimate the response rate for IFN-alpha plus either 13-cis-retinoic acid (13cRA) or all-trans-retinoic acid (ATRA) in women with recurrent cervical SCC. PATIENTS AND METHODS: Eligibility for this trial required bidimensionally measurable locally recurrent or metastatic squamous or adenosquamous carcinoma of the uterine cervix; SWOG performance status of </=2; no prior interferon, retinoids, or chemotherapy (except as radiation sensitization). All but two patients were previously treated with surgery, radiation therapy, or both. After randomization, patients received IFN-alpha-2A (subcutaneous injection; 3 x 10(6) units/m2/day) plus either 13cRA (1 mg/kg/day orally) or ATRA (150 mg/m2/day orally) in two equally divided doses. RESULTS: Total enrollment was 63 patients, 21 in the ATRA arm, 42 in the 13cRA arm. Three patients were ineligible, 1 in the ATRA arm, 2 in the 13cRA arm. Each arm had 1 patient who received no assigned treatment and was not evaluated for response or toxicity. The ATRA/IFN-alpha response rate was 5% (1/19; 95% confidence interval = 0.1-26%), consisting of 1 partial response lasting 4 weeks. The 13cRA/IFN-alpha response rate was 8% (3/39; 95% confidence interval = 2-21%), consisting of 3 partial responses lasting 17, 22, and 24 weeks, respectively. All confirmed responses were partial. One additional unconfirmed partial response occurred in the 13cRA arm. Both regimens were generally well-tolerated and produced toxicities (principally malaise and fatigue) associated with each constituent agent's known single-agent side effects. CONCLUSION: Based upon the results of this study, neither regimen can be recommended for further study in patients previously treated with radiation therapy.

Adult↗
PubMed1998

Prions and the prion disorders.

One of us remembers sitting in a high school biology class in 1977 being taught about scrapie, a naturally occurring disorder of sheep. The teacher had no particular interest in agriculture, but was pointing out some peculiar characteristics of this disease as a biological curiosity on a wet Friday afternoon. The prion disorders captured the imagination of a range of biologists (including that teacher) well before the epidemic of bovine spongiform encephalopathy (BSE) and the appearance of a new variant of the human prion disease, Creutzfeldt Jakob disease (CJD), in the UK, because of their extraordinary biology and the unique properties of the infectious agent. We review the results of studies leading to a convergence of evidence that the causative infectious agent, the 'prion', is devoid of nucleic acid and is composed of an abnormal isoform of a host-encoded protein, the prion protein (PrP).

Animals↗
PubMed1998

Interlaboratory concordance of DNA sequence analysis to detect reverse transcriptase mutations in HIV-1 proviral DNA. ACTG Sequencing Working Group. AIDS Clinical Trials Group.

Thirteen laboratories evaluated the reproducibility of sequencing methods to detect drug resistance mutations in HIV-1 reverse transcriptase (RT). Blinded, cultured peripheral blood mononuclear cell pellets were distributed to each laboratory. Each laboratory used its preferred method for sequencing proviral DNA. Differences in protocols included: DNA purification; number of PCR amplifications; PCR product purification; sequence/location of PCR/sequencing primers; sequencing template; sequencing reaction label; sequencing polymerase; and use of manual versus automated methods to resolve sequencing reaction products. Five unknowns were evaluated. Thirteen laboratories submitted 39043 nucleotide assignments spanning codons 10-256 of HIV-1 RT. A consensus nucleotide assignment (defined as agreement among > or = 75% of laboratories) could be made in over 99% of nucleotide positions, and was more frequent in the three laboratory isolates. The overall rate of discrepant nucleotide assignments was 0.29%. A consensus nucleotide assignment could not be made at RT codon 41 in the clinical isolate tested. Clonal analysis revealed that this was due to the presence of a mixture of wild-type and mutant genotypes. These observations suggest that sequencing methodologies currently in use in ACTG laboratories to sequence HIV-1 RT yield highly concordant results for laboratory strains; however, more discrepancies among laboratories may occur when clinical isolates are tested.

Codon↗
PubMed1998

End-of-life care for persons age 80 years or older.

At age 80, about 4 of every ten 10 men and 3 of every 10 women will die within 5 years. What should the very old expect of the dying experience? National data reveal that very old adults experience considerable variation in the use of the hospital during their last 6 months of life. Physicians report these patients most often need assistance with self-care, emotional support, nutrition, and pain control. In order to minimize unnecessary and expensive hospitalization and improve home management, specific terminal care guidelines are proposed and illustrated.

Aged↗