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Biomedical subjects

J Best

Publications and source records attributed to J Best.

At least 19 recordsLinked to original sources
PubMed2000

[Stopping secondary prevention in AIDS patients with inactive CMV retinitis treated with HAART (highly active antiretroviral therapy)].

BACKGROUND: Immune recovery of AIDS patients with cytomegalovirus (CMV) retinitis treated and healed by highly active antiretroviral therapy (HAART) is reflected by increased CD4 cell count and decreased virus load. Due to partial reconstitution of the immune status the risk of opportunistic infections decreases, as well as the risk of reactivating inactive CMV retinitis. It may therefore be possible to stop anti-CMV maintenance therapy may after HAART-induced immune recovery. PATIENTS AND METHODS: We present six patients (nine eyes) with a follow-up of 9.5 months (range 7-12 months) after cessation of the CMV-specific maintenance therapy (five orally, one intravenously). RESULTS: There was no reactivation of retinal CMV infection during the follow-up period. The virus load (< 50 Eq/ml; a single value of one patient was 2047 Eq/ml) and CD4 cell counts (range 207-454/microliter; mean: 313/microliter) remained stable during the follow-up period, reflecting immune recovery. CONCLUSIONS: Our findings confirm the expected low risk of retinal CMV reactivation after immune recovery in AIDS patients receiving HAART without secondary prophylaxis with an anti-CMV maintenance therapy. Regular ophthalmic and medical follow-up is mandatory in these patients. Cessation of maintenance therapy represents a major improvement in quality of live in AIDS patients.

AIDS-Related Opportunistic Infections↗
PubMed2000

Memory impairment in out-of-hospital cardiac arrest survivors is associated with global reduction in brain volume, not focal hippocampal injury.

BACKGROUND AND PURPOSE: More than 30% of out-of-hospital cardiac arrest (OHCA) survivors suffer significant memory impairment. The hippocampus may be vulnerable to hypoxic injury during cardiac arrest. The purpose of this study was to determine whether selective hippocampal injury is the substrate for this memory impairment. METHODS: Seventeen OHCA survivors and 12 patients with uncomplicated myocardial infarction were studied. OHCA survivors were divided into those with impaired and intact memory. Memory was assessed by use of the Rivermead Behavioural Memory Test and Doors and People Test. MRI was used to determine intracranial, whole-brain, amygdala-hippocampal complex, and temporal lobe volumes. Brain structure was also examined by statistical parametric mapping. RESULTS: Left amygdala-hippocampal volume was reduced in memory-impaired OHCA victims compared with control subjects (mean 3. 93 cm(3) and 95% CI 3.50 to 4.36 cm(3) versus mean 4.65 cm(3) and 95% CI 4.37 to 4.93 cm(3); P=0.002). Left temporal lobe and whole-brain volumes were also reduced. There were no differences in amygdala-hippocampal volume indexed against ipsilateral temporal lobe volume. Significant correlations were observed between total brain volume and Rivermead Behavioural Memory Test (r=0.56, P<0.05) and Doors and People Test (r=0.67, P<0.01) scores in OHCA survivors. Both recall and recognition were compromised in memory-impaired subjects. Statistical parametric mapping did not detect focal brain abnormalities in these subjects. Global cerebral atrophy was confirmed by qualitative assessment. CONCLUSIONS: Memory impairment in OHCA survivors is associated with global cerebral atrophy, not selective hippocampal damage. Rehabilitation protocols need to account for the global nature of the brain injury.

Aged↗
PubMed2000

Treating elevated lipids. Does it make a difference?

BACKGROUND: There is now abundant evidence from clinical trials that treatment with lipid modifying therapy will decrease the risk of coronary heart disease (CHD). The decision to treat a patient, whether with advice on lifestyle modification or with drug therapy, needs to be based on consideration of costs versus benefits. OBJECTIVE: To assess the evidence from primary and secondary prevention studies for cardiovascular benefit of cholesterol lowering medication. DISCUSSION: Treating hypercholesterolaemia reduces the relative risk of major CHD events by about 30%. The greatest benefit of lipid lowering treatment is in the high risk group. This group shows the greatest reduction in absolute risk and therefore a 'smaller number to treat' to prevent one major CHD event. In the moderate risk group three times as many individuals require treatment to prevent one major CHD event. However, this corresponds to the benefit in primary prevention of stroke by treating mild-moderate hypertension in middle aged men.

Coronary Disease↗
PubMed1999

Cystoid macular edema following immune recovery and treatment with cidofovir for cytomegalovirus retinitis.

BACKGROUND: Cytomegalovirus (CMV) retinitis is the most common opportunistic ocular infection in AIDS patients. Cidofovir has proved to be highly effective in treatment of CMV retinitis. Iritis and bulbar hypotony are known as the major complications after intravenous and intravitreal use of this antiviral drug. Cystoid macular edema (CME) after intravenous application of cidofovir has not been reported. METHODS: We analyzed retrospectively the incidence of CME after intravitreal or intravenous application of cidofovir and its correlation with CD4 cell counts of the patients. RESULTS: Two (22.2%) of 9 eyes in the intravenous and 3 (18.8%) of 16 eyes in the intravitreal injection group developed CME. It occurred between 3 and 48 weeks after cidofovir administration. In all eyes CMV retinitis was inactive. All patients received highly active antiretroviral treatment (HAART). CME was correlated with a rapid and sustained improvement in CD4 cell counts. CONCLUSION: We interpret the occurrence of CME as an immune recovery phenomenon for the following reasons. All CMEs were seen in eyes with inactive CMV retinitis and the unaffected contralateral side never developed CME. The time range of appearance between 3 and 48 weeks after cidofovir administration makes direct toxicity of cidofovir unlikely. All patients had a sustained improvement of CD4 cell counts due to HAART. No CME was reported during the use of cidofovir before the HAART era.

AIDS-Related Opportunistic Infections↗
PubMed1999

Implementing and sustaining evidence-based clinical practice in Australia: the Evidence Based Clinical Practice Research Initiative.

Evidence-based medicine is a process by which clinicians translate clinical information needs into answerable questions, track down answers to those needs as efficiently and effectively as possible using the best evidence available, apply the information to patients and evaluate their performance. Implementing evidence-based medicine is fragmented and variable. The National Health and Medical Research Council of Australia has implemented a research program to determine successful strategies for implementation and sustaining of evidence-based clinical practice. In addition this research program will help to answer whether evidence-based practice improves patient outcomes. This paper describes this program and other strategies that improve the application of evidence-based practice in clinical settings.

Australia↗
PubMed1998

Risks and costs of end-stage renal disease after heart transplantation.

OBJECTIVES: To estimate the risks and costs of end-stage renal disease (ESRD) after heart transplantation. BACKGROUND: Previous studies have shown high rates of ESRD among solid-organ transplant patients, but the relevance of these studies for current transplant practices and policies is unclear. Limitations of prior studies include relatively small, single-center samples and estimates made before implementing suggested practice changes to reduce ESRD risk. METHODS: Medicare beneficiaries who underwent heart transplantation between 1989 and 1994 were eligible for study inclusion (n=2088). Thirty-four patients undergoing dialysis or who had the diagnosis of ESRD before or at transplantation were excluded from the study. ESRD was defined as any patient undergoing renal transplantation or requiring dialysis for more than 3 months. Mortality and ESRD events were recorded up to 1995. ESRD risk was estimated using the Kaplan-Meier product-limit estimator and logistic regression analyses. Linear regression was performed to determine expenditures for treating ESRD, and we developed long-term models of the risk and direct medical costs of ESRD care. RESULTS: The annual risk of ESRD was 0.37% in the first year after transplant and increased to 4.49% by the sixth posttransplant year. There was no significant trend in the risk of ESRD based on the year of transplantation, even after adjusting for patient characteristics. The average cumulative 10-year direct cost of ESRD per patient undergoing heart transplantation exceeded $13,000. CONCLUSIONS: In a large, national sample of patients undergoing heart transplantation, ESRD is not rare, even for patients undergoing transplant after the development of new practices intended to reduce its occurrence. ESRD remains an important component of the costs of heart transplantation.

Adult↗
PubMed1997

Novel inhibitors of cytokine-induced IkappaBalpha phosphorylation and endothelial cell adhesion molecule expression show anti-inflammatory effects in vivo.

We have identified two compounds that inhibit the expression of endothelial-leukocyte adhesion molecules intercellular adhesion molecule-1, vascular cell adhesion molecule-1, and E-selectin. These compounds act by inhibiting tumor necrosis factor-alpha-induced phosphorylation of IkappaB-alpha, resulting in decreased nuclear factor-kappaB and decreased expression of adhesion molecules. The effects on both IkappaB-alpha phosphorylation and surface expression of E-selectin were irreversible and occurred at an IC50 of approximately 10 microM. These agents selectively and irreversibly inhibited the tumor necrosis factor-alpha-inducible phosphorylation of IkappaB-alpha without affecting the constitutive IkappaB-alpha phosphorylation. Although these compounds exhibited other activities, including stimulation of the stress-activated protein kinases, p38 and JNK-1, and activation of tyrosine phosphorylation of a 130-140-kDa protein, these effects are probably distinct from the effects on adhesion molecule expression since they were reversible. One compound was evaluated in vivo and shown to be a potent anti-inflammatory drug in two animal models of inflammation. The compound reduced edema formation in a dose-dependent manner in the rat carrageenan paw edema assay and reduced paw swelling in a rat adjuvant arthritis model. These studies suggest that inhibitors of cytokine-inducible IkappaBalpha phosphorylation exert anti-inflammatory activity in vivo.

Animals↗
PubMed1997

A multicenter, double-blind, one-year study comparing safety and efficacy of atorvastatin versus simvastatin in patients with hypercholesterolemia.

We directly compared the safety and efficacy of atorvastatin and simvastatin in hypercholesterolemic patients. This 1-year, randomized, double-blind study was performed at 9 community- and university-based research hospitals in Australia. One-hundred seventy-seven patients between the ages of 18 and 80 years with baseline low-density-lipoprotein (LDL) cholesterol > or = 4.14 and < or = 7.76 mmol/L (160 and 300 mg/dl, respectively) and triglycerides < or = 4.52 mmol/L (400 mg/dl) received once-daily dosing with atorvastatin (Lipitor) 10 mg or simvastatin (Zocor) 10 mg. At week 16, the dose of medication was titrated to atorvastatin 20 mg or simvastatin 20 mg if patients did not meet LDL cholesterol target of < or = 3.36 mmol/L (130 mg/dl). Efficacy was reported as percent change from baseline in LDL cholesterol, total cholesterol, very low density lipoprotein cholesterol, total triglycerides, high-density lipoprotein cholesterol, apolipoproteins AI and B, and lipoprotein(a). Atorvastatin caused significantly greater reductions from baseline than did simvastatin for LDL cholesterol, total cholesterol, very low density lipoprotein cholesterol, triglycerides, and apolipoprotein B (p <0.05). No patient in either treatment group had clinically important elevations in creatine phosphokinase, alanine aminotransaminase, or aspartate aminotransaminase. No serious adverse events were considered associated with treatment. With atorvastatin 10 mg, 46% of the patients achieved LDL cholesterol target goal by week 16, whereas only 27% of the simvastatin patients achieved the target goal at the 10-mg dose. This cholesterol-lowering profile affords utility in many patient types.

Adult↗
PubMed1997

Tumor necrosis factor alpha-induced E-selectin expression is activated by the nuclear factor-kappaB and c-JUN N-terminal kinase/p38 mitogen-activated protein kinase pathways.

E-selectin expression by endothelium is crucial for leukocyte recruitment during inflammatory responses. Transcriptional regulation of the E-selectin promoter by tumor necrosis factor alpha (TNFalpha) requires multiple nuclear factor-kappaB (NF-kappaB) binding sites and a cAMP-responsive element/activating transcription factor-like binding site designated positive domain II (PDII). Here we characterize the role of the stress-activated family of mitogen-activated protein (MAP) kinases in induced expression of this adhesion molecule. By UV cross-linking and immunoprecipitation, we demonstrated that a heterodimer of transcription factors ATF-2 and c-JUN is constitutively bound to the PDII site. TNFalpha stimulation of endothelial cells induces transient phosphorylation of both ATF-2 and c-JUN and induces marked activation of the c-JUN N-terminal kinase (JNK1) and p38 but not extracellular signal-regulated kinase (ERK1). JNK and p38 are constitutively present in the nucleus, and DNA-bound c-JUN and ATF-2 are stably contacted by JNK and p38, respectively. MAP/ERK kinase kinase 1 (MEKK1), an upstream activator of MAP kinases, increases E-selectin promoter transcription and requires an intact PDII site for maximal induction. MEKK1 can also activate NF-kappaB -dependent gene expression. The effects of dominant interfering forms of the JNK/p38 signaling pathway demonstrate that activation of these kinases is critical for cytokine-induced E-selectin gene expression. Thus, TNFalpha activates two signaling pathways, NF-kappaB and JNK/p38, which are both required for maximal expression of E-selectin.

Activating Transcription Factor 2↗
PubMed1997

A brief review paper of the efficacy and safety of atorvastatin in early clinical trials.

Preclinical and clinical data on atorvastatin, a new 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitor, indicate that it has superior activity in treating a variety of dyslipidemic disorders characterized by elevations in low-density lipoprotein cholesterol (LDL-C) and/or triglycerides. Results for patients randomized in early efficacy and safety studies were combined in one database and analyzed. This analysis included a total of 231 atorvastatin-treated patients (131 with hypercholesterolemia (HC), 63 with combined hyperlipidemia (CH), 36 with hypertriglyceridemia (HTG), and 1 with hyperchylomicronemia (Fredrickson Type V)). Patients were treated with a cholesterol-lowering diet (National Institutes of Health National Cholesterol Education Program Step 1 diet or a more rigorous diet) and either 2.5, 5, 10, 20, 40, or 80 mg/day of atorvastatin or placebo. Efficacy was based on percent change from baseline in total cholesterol, total triglycerides, LDL-C, very low-density lipoprotein cholesterol (VLDL-C), high-density lipoprotein cholesterol (HDL-C), apolipoprotein B (apo B), and non-HDL-C/HDL-C. Safety was assessed in all randomized patients. Atorvastatin seemed to preferentially lower those lipid and lipoprotein component(s) most elevated within each dyslipidemic state: LDL-C in patients with HC, triglycerides and VLDL-C in patients with HTG, or all 3 in patients with CH. Atorvastatin was well-tolerated with a safety profile similar to other drugs in its class.

Adult↗
PubMed1997

The role of abdominal adiposity and insulin resistance in dyslipidemia of chronic renal failure.

The atherogenic profile of high triglyceride, reduced high-density lipoprotein (HDL) cholesterol, and small low-density lipoprotein particle size found in patients on chronic hemodialysis is known to be associated with insulin resistance and abdominal obesity in the general population. To assess the influence of insulin resistance and abdominal adiposity on the lipid profile in subjects on hemodialysis, intravenous glucose tolerance test and dual-energy x-ray absorptiometry were performed in 26 nondiabetic subjects on hemodialysis and compared with 22 nondiabetic control subjects matched for age, sex, and body mass index. Subjects on hemodialysis were found to have higher triglyceride (133 mg/dL [95% confidence interval, 115 to 159 mg/dL] v 97 mg/dL [95% confidence interval, 80 to 124 mg/dL]; P < 0.05), lower HDL cholesterol (36 +/- 3 mg/dL v 51 +/- 4 mg/dL [mean +/- SEM]; P < 0.01), enhanced insulin response to glucose (2.72 +/- 0.28 mUL(-1) min per mg dL(-1) v 1.67 +/- 0.22 mUL(-1) min per mg dL(-1); P < 0.01), and reduced sensitivity to the action of insulin (2.24 min(-1) per mUL(-1) min [95% confidence interval, 1.86 to 2.75 min(-1) per mUL(-1) min] v 4.17 min(-1) mUL(-1) min [95% confidence interval, 2.95 to 5.9 min(-1) per mUL(-1) min]; P < 0.01) than the control subjects. Abdominal adiposity measured by dual-energy x-ray absorptiometry (2,004 +/- 210 g v 2,163 +/- 198 g [mean +/- SEM]; P = NS) and percentage of body fat distributed to the abdomen (10.5% +/- 0.3% v 9.7% +/- 0.5% [mean +/- SEM]; P = NS) did not differ between the two groups. Subjects on hemodialysis were insulin resistant, but unlike control subjects, their lipid profile was not predicted by their insulin sensitivity. Abdominal adiposity was associated with a deteriorating lipid profile and insulin resistance in subjects on hemodialysis, as it was in control subjects. The presence of renal failure resulted in additional insulin resistance and a higher triglyceride level in the leaner subjects on hemodialysis compared with control subjects with similar levels of abdominal fat. In the more obese subjects, insulin sensitivity and triglyceride level did not differ between the two groups of subjects, although HDL cholesterol level remained low in subjects on hemodialysis. In conclusion, insulin resistance in subjects on hemodialysis did not directly account for their abnormal lipid profile. The negative impact of abdominal adiposity on the metabolic profile was preserved in subjects on hemodialysis, but the presence of renal failure itself resulted in insulin resistance in the leaner subjects and dyslipidemia in all subjects on hemodialysis compared with control subjects of comparable abdominal adiposity.

Abdomen↗
PubMed1997

High density lipoprotein (HDL) particle composition in patients with end stage renal failure (ESRF) on chronic dialysis.

BACKGROUND: Hypertriglyceridaemia, low high density lipoprotein (HDL) cholesterol level and reduced LDL particle size are the major features of uraemic dyslipidaemia. They are also found in the Insulin Resistance Syndrome. AIM: To examine alterations in HDL composition in patients on chronic dialysis and their relationship with insulin resistance. METHODS: HDL particle size was determined in 33 patients on chronic haemodialysis (HD), 27 on chronic ambulatory peritoneal dialysis (CAPD) and 32 control non-diabetic subjects (C) without renal disease by non-denaturing 3-30% polyacrylamide gradient gel electrophoresis. A weighted HDL particle size score was calculated taking into account both HDL particle size and percentage total HDL protein concentration of each HDL band of the individual. Lipid and apolipoliprotein concentrations were determined in HDL2 and HDL3 particles obtained by sequential ultracentrifugation. In a subset of 24 control subjects and 22 subjects on HD, insulin sensitivity was also determined by an intravenous glucose tolerance test (IVGTT). RESULTS: HDL particles were found to be more triglyceride enriched and apoAI depleted in subjects on HD even though plasma triglyceride level was highest in patients on CAPD. Five subpopulations of HDL particles were identified by gradient gel electrophoresis in all subjects combined. In the subgroup of subjects who underwent IVGTT, the weighted HDL particle size score correlated positively with HDL cholesterol level (r = 0.6, p < 0.0005), LDL particle size (r = 0.47, p < 0.001), and insulin sensitivity (r = 0.48, p < 0.001), and negatively with plasma triglyceride level (r = 0.37, p < 0.01). CONCLUSIONS: We conclude that even though HDL cholesterol is reduced to a similar level in subjects on both forms of dialysis for end stage renal failure, abnormalities of HDL composition are more marked in subjects on HD. Reduction in HDL particle size is linked with insulin resistance and accompanies reduction in LDL particle size and hypertriglyceridaemia.

Cholesterol, HDL↗
PubMed1996

Low-density lipoprotein particle size distribution in end-stage renal disease treated with hemodialysis or peritoneal dialysis.

Dyslipidemia accompanies end-stage renal disease (ESRD) and contributes to the high incidence of cardiovascular disease in patients on chronic dialysis treatment. The lipid abnormalities of elevated triglyceride level and reduced high-density lipoprotein cholesterol level that occur in ESRD are associated in the normal population with an altered distribution of low-density lipoprotein (LDL) particle size, a pattern associated with increased risk of coronary heart disease. To assess the effect of ESRD on LDL particle size distribution, we examined plasma lipid levels and LDL particle size in 43 subjects on chronic hemodialysis, 23 subjects on continuous ambulatory peritoneal dialysis, and 30 control subjects with normal renal function. Of subjects on continuous ambulatory peritoneal dialysis, 48% had small LDL particle size compared with 23% of subjects on hemodialysis and 7% of control subjects. Subjects on both forms of dialysis also had higher triglyceride levels and lower high-density lipoprotein cholesterol levels that correlated with LDL particle size. We conclude that altered LDL particle size forms an important component of the metabolic abnormalities that contribute to the increased cardiovascular risk found in ESRD.

Case-Control Studies↗
PubMed1996

Characterization of NERF, a novel transcription factor related to the Ets factor ELF-1.

We have cloned the gene for a novel Ets-related transcription factor, new Ets-related factor (NERF), from human spleen, fetal liver, and brain. Comparison of the deduced amino acid sequence of NERF with those of other members of the Ets family reveals that the level of homology to ELF-1, which is involved in the regulation of several T- and B-cell-specific genes, is highest. Homologies are clustered in the putative DNA binding domain in the middle of the protein, a basic domain just upstream of this domain, and several shorter stretches of homology towards the amino terminus. The presence of two predominant NERF transcripts in various fetal and adult human tissues is due to at least three alternative splice products, NERF-1a, NERF-1b, and NERF-2, which differ in their amino termini and their expression in different tissues. Only NERF-2 and ELF-1, and not NERF-1a and NERF-1b, function as transcriptional activators of the lyn and blk gene promoters, although all isoforms of NERF bind with affinities similar to those of ELF-1 to a variety of Ets binding sites in, among others, the blk, lck, lyn, mb-1, and immunoglobulin H genes and are expressed at similar levels. Since NERF and ELF-1 are coexpressed in B and T cells, both might be involved in the regulation of the same genes.

Adult↗