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Biomedical subjects

D C Spencer

Publications and source records attributed to D C Spencer.

At least 19 recordsLinked to original sources
PubMed2000

The role of the intracarotid amobarbital procedure in evaluation of patients for epilepsy surgery.

PURPOSE: To examine the role of the intracarotid amobarbital procedure (IAP) in the presurgical evaluation of patients with medically refractory localization-related epilepsy. METHODS: We retrospectively studied 111 patients who underwent cortical resective surgery at our center between 1991 and 1996. In patients with mesial temporal lobe epilepsy (mTLE), a presurgical determination of the epileptogenic zone was compared with localization based on IAP memory asymmetry scores, and with ultimate localization after resective surgery. In patients with neocortical or mesial frontal epilepsy, the IAP was evaluated for evidence of unilateral or bilateral poor memory performance. RESULTS: Of 68 patients with mTLE localized by noninvasive tests, 60 had concordant lateralized memory deficits on IAP. Eight patients had lateralized memory deficits on IAP that were discordant with noninvasive tests and with localization as determined by surgical outcome. All 11 mTLE patients requiring invasive EEG monitoring were correctly lateralized by IAP, including one patient in whom the noninvasive evaluation otherwise provided false lateralization. Of 32 patients with neocortical or mesial frontal lobe epilepsy, 21 displayed memory deficits on IAP. Of 10 patients with bilateral deficits, five had mesial frontal lobe epilepsy. In 13 patients with lateralized memory deficits, seven underwent electrode implantation in the mesial temporal lobe, and four ultimately underwent resection of an epileptogenic mesial temporal lobe in addition to a neocortical resection. CONCLUSIONS: In patients with mTLE, lateralized memory deficits on IAP usually confirm localization provided by noninvasive tests. However, in mTLE not well lateralized by the noninvasive evaluation, and in neocortical or mesial frontal epilepsy, the IAP may provide information regarding localization that ultimately alters surgical management.

Adolescent↗
PubMed2000

February 2000: Dementia with motor dysfunction in a patient with liver disease.

Acquired (non-Wilsonian) hepatocerebral degeneration (AHCD) is an irreversible neurological condition characterized by dementia, dysarthria, and motor disturbances. It has been described in patients with severe liver disease of many causes, and notably in patients with surgically or spontaneously created porto-systemic shunts. We report a case of AHCD in a patient with end-stage liver disease due to alcohol abuse and hepatitis C. In addition, this patient showed pathologic evidence of the less commonly reported "shunt myelopathy" in the absence of a surgically created porto-systemic shunt. The myelopathy was associated with a dramatic vacuolation involving especially the deep motor cortex. Electron microscopy suggested that the vacuolation was due mainly to disruption of abnormal astrocytes.

Aged↗
PubMed1999

The long-term outcome of patients with IgA nephropathy treated with fish oil in a controlled trial. Mayo Nephrology Collaborative Group.

It was reported previously that dietary fish oil supplementation retarded the progression of renal disease in patients with IgA nephropathy in a multicenter, placebo-controlled, randomized, 2-yr clinical trial. The aim of this study was to determine the long-term influence of fish oil treatment on renal progression in observations on the study cohort of 106 patients extending beyond the 2-yr trial. Renal function was assessed by serial serum creatinine and 24-h urine protein measurements. Vital, end-stage renal disease (ESRD), and BP status and treatment beyond completion of the 2-yr trial were determined. As in the trial, the primary end point was an increase of 50% or more in the serum creatinine, and the secondary end point was ESRD. After a mean follow-up of 6.4 yr, 46 patients-17 in the fish oil group versus 29 in the placebo group-reached the primary end point (P = 0.002), and 27 patients-eight in the fish oil group versus 19 in the placebo group-developed ESRD (P = 0.009). At the end of the 2-yr trial, 75 patients (45 fish oil, 30 placebo) remained at risk for the primary end point. This is also when the double-blind part of the trial ended, allowing physicians to stop supplements, switch original placebo-assigned patients to fish oil, and continue fish oil in original fish oil-assigned patients. A significantly greater number of nonsupplemented placebo patients developed the primary end point (P = 0.02) and ESRD (P = 0.003) compared with long-term supplemented fish oil patients. Conversely, more fish oil-supplemented patients had stable renal function than nonsupplemented patients (P = 0.02). By intention, BP control, primarily treated with angiotensin-converting enzyme inhibition, was equal in the fish oil and placebo groups. Proteinuria was modestly reduced in both groups. It is concluded that early and prolonged treatment with fish oil slows renal progression for high-risk patients with IgA nephropathy.

Angiotensin-Converting Enzyme Inhibitors↗
PubMed1997

Clinical trials of interactive computerized patient education: implications for family practice.

A systematic review of randomized clinical trials was conducted to evaluate the acceptability and usefulness of computerized patient education interventions. The Columbia Registry, MEDLINE, Health, BIOSIS, and CINAHL bibliographic databases were searched. Selection was based on the following criteria: (1) randomized controlled clinical trials, (2) educational patient-computer interaction, and (3) effect measured on the process or outcome of care. Twenty-two studies met the selection criteria. Of these, 13 (59%) used instructional programs for educational intervention. Five studies (22.7%) tested information support networks, and four (18%) evaluated systems for health assessment and history-taking. The most frequently targeted clinical application area was diabetes mellitus (n = 7). All studies, except one on the treatment of alcoholism, reported positive results for interactive educational intervention. All diabetes education studies, in particular, reported decreased blood glucose levels among patients exposed to this intervention. Computerized educational interventions can lead to improved health status in several major areas of care, and appear not to be a substitute for, but a valuable supplement to, face-to-face time with physicians.

Adolescent↗
PubMed1997

Development of an HIV clinical and research database for South Africa.

Health service restructuring in South Africa provides an opportunity to introduce appropriate Health Information System (HIS) technology. This is particularly relevant given the emerging HIV epidemic and the need to capture, translate and disseminate new experiences in HIV/AIDS care, support and clinical research. In 1994, a number of clinicians and health-care providers working in South Africa had begun to establish basic computerized databases to assist in research on HIV, but no standardized nomenclature or framework for collaboration was created. This paper describes a clinical and research database that could be used as an example for a standardized system by clinicians working in South Africa. The authors, with assistance from the National AIDS Research Programme of the Medical Research Council, created a prototype relational database using Microsoft Access. To test the prototype, 1057 HIV-positive patients from the infectious Disease Clinic at Johannesburg General Hospital were entered.

Databases, Factual↗
PubMed1996

Investigation of tick-borne viruses as pathogens of humans in South Africa and evidence of Dugbe virus infection in a patient with prolonged thrombocytopenia.

In the course of investigating suspected cases of viral haemorrhagic fever in South Africa patients were encountered who had been bitten by ticks, but who lacked evidence of infection with Crimean-Congo haemorrhagic fever (CCHF) virus or non-viral tick-borne agents. Cattle sera were tested by enzyme-linked immunoassay to determine whether tick-borne viruses other than CCHF occur in the country. The prevalence of antibody in cattle sera was 905/2116 (42.8%) for CCHF virus, 70/1358 (5.2%) for Dugbe, 21/1358 (1.5%) for louping ill, 6/450 (1.3%) for West Nile, 7/1358 (0.5%) for Nairobi sheep disease, 3/625 (0.5%) for Kadam and 2/450 (0.4%) for Chenuda. No reactions were recorded with Hazara, Bahig, Bhanja, Thogoto and Dhori viruses. The CCHF findings confirmed previous observations that the virus is widely prevalent within the distribution range of ticks of the genus Hyalomma, while antibody activity to Dugbe antigen was detected only within the distribution range of the tick Amblyomma hebraeum. Cross-reactivity for the nairoviruses, Hazara, Nairobi sheep disease and Dugbe, was detected in serum samples from 3/72 human patients with confirmed CCHF infection, and serum from 1/162 other patients reacted monospecifically with Dugbe antigen. The latter patient suffered from febrile illness with prolonged thrombocytopenia.

Animals↗
PubMed1995

Assessing the quality of primary care: the use and importance of reimbursement data.

Although inpatient quality assessment efforts have advanced greatly in recent years, similar growth has not yet been experienced in ambulatory care. However, given the growth of primary care and its role in managed care systems, the need for quality assessment innovations is great and the future looks promising. The authors describe their experience in developing such an innovation in an ambulatory care setting. The goal of this article is to identify and describe how secondary data--in particular, data from reimbursement systems--may be used to develop a primary care quality of care assessment system. This investigation highlights the importance of reimbursement data in developing clinically meaningful and practical models for quality assessment.

Adolescent↗
PubMed1994

A controlled trial of fish oil in IgA nephropathy. Mayo Nephrology Collaborative Group.

BACKGROUND: The n-3 fatty acids in fish oil affect eicosanoid and cytokine production and therefore have the potential to alter renal hemodynamics and inflammation. The effects of fish oil could prevent immunologic renal injury in patients with IgA nephropathy. METHODS: In a multicenter, placebo-controlled, randomized trial we tested the efficacy of fish oil in patients with IgA nephropathy who had persistent proteinuria. The daily dose of fish oil was 12 g; the placebo was a similar dose of olive oil. Serum creatinine concentrations, elevated in 68 percent of the patients at base line, and creatinine clearance were measured for two years. The primary end point was an increase of 50 percent or more in the serum creatinine concentration at the end of the study. RESULTS: Fifty-five patients were assigned to receive fish oil, and 51 to receive placebo. According to Kaplan-Meier estimation, 3 patients (6 percent) in the fish-oil group and 14 (33 percent) in the placebo group had increases of 50 percent or more in their serum creatinine concentrations during treatment (P = 0.002). The annual median changes in the serum creatinine concentrations were 0.03 mg per deciliter (2.7 mumol per liter) in the fish-oil group and 0.14 mg per deciliter (12.4 mumol per liter) in the placebo group. Proteinuria was slightly reduced and hypertension was controlled to a comparable degree in both groups. The cumulative percentage of patients who died or had end-stage renal disease was 40 percent in the placebo group after four years and 10 percent in the fish-oil group (P = 0.006). No patient discontinued fish-oil treatment because of adverse effects. CONCLUSIONS: In patients with IgA nephropathy, treatment with fish oil for two years retards the rate at which renal function is lost.

Adult↗
PubMed1994

Essential fatty acid deficiency profiles in idiopathic immunoglobulin A nephropathy.

The profiles of fatty acids (FAs) of plasma phospholipids (the compartment reflecting the essential FA status of tissue lipids), nonesterified FAs (the precursor pool for autacoid synthesis), urine protein excretion, and glomerular filtration rate were measured before and after supplementation with fish oil in 15 patients with immunoglobulin A nephropathy. In the FA profiles, there was deficient 18:3 omega 3 (alpha-linolenic acid), the parent compound of omega 3 polyunsaturated FA, and deficient chain elongation products of both omega 3 and omega 6 polyunsaturated FAs with replacement by saturated and monounsaturated short-chain, odd-chain, and branched-chain FAs, producing significant loss of omega 3 FA. These alterations indicate nutritional or functional (omega 3) and metabolic (omega 6) deficiencies. Additionally, the mean melting point of the FAs was significantly increased, implying an inherent decrease in cell membrane fluidity. Enhancement of 20: 5 omega 3 (eicosapentaenoic acid) and 22:6 omega 3 (docosahexaenoic acid) and suppression of 20:4 omega 6 (arachidonate) after supplementation with fish oil were accompanied by important decreases in proteinuria and improved glomerular filtration rate. Omega-3 polyunsaturated FAs may favorably influence immunoglobulin A nephropathy through a modulation of the pathologic actions of the omega 6 eicosanoids and other diverse actions on various mediators produced by an initial immune injury.

Adult↗
PubMed1994

A decision-support system for the analysis of clinical practice patterns.

Several studies documented substantial variation in medical practice patterns, but physicians often do not have adequate information on the cumulative clinical and financial effects of their decisions. The purpose of developing an expert system for the analysis of clinical practice patterns was to assist providers in analyzing and improving the process and outcome of patient care. The developed QFES (Quality Feedback Expert System) helps users in the definition and evaluation of measurable quality improvement objectives. Based on objectives and actual clinical data, several measures can be calculated (utilization of procedures, annualized cost effect of using a particular procedure, and expected utilization based on peer-comparison and case-mix adjustment). The quality management rules help to detect important discrepancies among members of the selected provider group and compare performance with objectives. The system incorporates a variety of data and knowledge bases: (i) clinical data on actual practice patterns, (ii) frames of quality parameters derived from clinical practice guidelines, and (iii) rules of quality management for data analysis. An analysis of practice patterns of 12 family physicians in the management of urinary tract infections illustrates the use of the system.

Artificial Intelligence↗
PubMed1994

Clinical and histopathologic associations with impaired renal function in IgA nephropathy. Mayo Nephrology Collaborative Group.

A multicenter, double-blind, placebo-controlled, randomized trial of fish oil in proteinuric patients with IgA nephropathy is being conducted by the Mayo Nephrology Collaborative Group. We completed enrollment of 106 patients into the trial in December 1991. The treatment period is for two years. Hypertension is being managed in all patients with enalapril maleate (Vasotec). We evaluated the associations between a variety of clinical and renal morphologic features and renal function at the entry of all enrolled patients. Among 78 males and 28 females [age(mean +/- SD) 36 +/- 14 years], older age at treatment randomization, hypertension, at disease discovery as well as at study entry, increased fractional excretion of albumin, increased serum triglyceride levels, and more severe tubulointerstitial, vascular, and combined glomerular and tubulointerstitial histologic lesions were all univariately associated (p < or = 0.01) with poorer renal function measured by reciprocal serum creatinine and creatinine clearance levels. In a multiple regression analysis used to predict baseline reciprocal creatinine, the best final model (R2 = 0.48) included male sex (p < .001), hypertension at treatment randomization (p = .001), decreased peripheral blood erythrocytes (p = .001), increased tubulointerstitial score (p = .004), and increased fractional excretion of albumin (p = .025) as independent predictors of decreased kidney function. These associations are similar to those seen in the high-risk subset of patients with IgA nephropathy who develop end-stage renal disease. In the eventual outcome analysis of the clinical trial, we will examine the effects of treatment on the two potentially modifiable risk factors, hypertension and proteinuria, on renal function.

Adult↗
PubMed1992

Human immunodeficiency virus and the central nervous system.

Neurological disease frequently complicates HIV-1 infection. In addition to opportunistic infections, a syndrome of combined cognitive and motor impairment, referred to as the AIDS dementia complex, has been recognized. While presumed to relate to HIV-1 itself, the pathogenesis of this syndrome remains uncertain. Because of the limited extent of productive brain HIV-1 infection in many cases, and because such infection involves macrophages and microglia rather than cells of neuroectodermal origin, current speculation centers on indirect mechanisms of brain injury including virus- or cell-coded neurotoxins. We review clinical and laboratory studies and also describe models of the interaction of HIV-1 and immune responses that might account for brain injury.

Central Nervous System Diseases↗