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Biomedical subjects

H A Austin

Publications and source records attributed to H A Austin.

At least 37 records · Page 2Linked to original sources
PubMed1995

Systemic lupus erythematosus: emerging concepts. Part 1: Renal, neuropsychiatric, cardiovascular, pulmonary, and hematologic disease.

PURPOSE: To review advances and controversies in the diagnosis and management of systemic lupus erythematosus with visceral involvement (renal, neuropsychiatric, cardiopulmonary, and hematologic disease). DATA SOURCES AND STUDY SELECTION: Review of the English-language medical literature with emphasis on articles published in the last 5 years. More than 400 articles were reviewed. DATA SYNTHESIS: Recent debates pertaining to lupus nephritis have focused on the value of kidney biopsy data and the role of cytotoxic drug therapies. Many studies have shown that estimates of prognosis are enhanced by consideration of clinical, demographic, and histologic features. For patients with severe lupus nephritis, an extended course of pulse cyclophosphamide therapy is more effective than a 6-month course of pulse methylprednisolone therapy in preserving renal function. Adding a quarterly maintenance regimen to monthly pulse cyclophosphamide therapy reduces the rate of exacerbations. Plasmapheresis appears not to enhance the effectiveness of prednisone and daily oral cyclophosphamide. Small case series have shown pulses of cyclophosphamide to be beneficial in patients with lupus and neuropsychiatric disease refractory to glucocorticoid therapy, acute pulmonary disease (pneumonitis or hemorrhage), and thrombocytopenia. Patients with systemic lupus erythematosus have an increased prevalence of valvular and atherosclerotic heart disease, apparently because of factors related to the disease itself and to drug therapy. CONCLUSIONS: Cytotoxic agents are superior to glucocorticoid therapy for the treatment of proliferative lupus nephritis, but the optimal duration and intensity of cytotoxic therapy remain undefined. Definitive studies of the treatment of autoimmune thrombocytopenia and acute pulmonary disease and of the diagnosis and treatment of neuropsychiatric disease are not available.

Cardiovascular Diseases↗
PubMed1995

Long-term outcome of hepatitis B virus-related glomerulonephritis after therapy with interferon alfa.

BACKGROUND & AIMS: Glomerulonephritis is an uncommon complication of chronic hepatitis B virus (HBV) infection in adults. A high percentage of patients seem to have short-term response to interferon therapy with improvement of proteinuria. The aim of this study was to assess the long-term response of patients with HBV-related glomerulonephritis to interferon alfa therapy. METHODS: All patients with chronic hepatitis B and glomerulonephritis who were treated with interferon alfa at the National Institutes of Health between 1985 and 1993 were assessed. RESULTS: Of the 15 patients treated, 8 (53%) had a long-term serological response with sustained loss of serum hepatitis B e antigen and HBV DNA. After 1-7 years of follow-up, all 8 responders have normal serum aminotransferase levels and 5 are hepatitis B surface antigen negative. Seven of the responders also showed a gradual but marked improvement in proteinuria. In contrast, the 7 nonresponders continued to have evidence of active renal disease and 1 required long-term dialysis therapy. All 8 responders had membranous glomerulonephritis, whereas 4 of 7 nonresponders had membranoproliferative glomerulonephritis. CONCLUSIONS: Interferon alfa therapy resulted in long-term remission in liver disease in 8 of 15 patients with chronic hepatitis B and glomerulonephritis. This response was accompanied by significant improvement in markers of renal disease in the majority of patients.

Adult↗
PubMed1995

High-risk features of lupus nephritis: importance of race and clinical and histological factors in 166 patients.

BACKGROUND: The pleomorphic nature of lupus nephritis has confounded efforts to refine estimates of prognosis. Consideration of interactions among prognostic factors may help to identify high-risk patients. METHODS: By univariate and multivariate survival analysis, race and attributes of severe active lupus nephritis were evaluated as potentially important prognostic factors in 166 patients upon entry into prospective therapeutic trials of lupus kidney disease. RESULTS: Black patients were significantly more likely than others to develop renal insufficiency. Cellular crescents emerged as the most predictive active pathological feature and interstitial fibrosis was the strongest chronic histological prognostic factor. Combinations of these morphological attributes identified particularly high-risk individuals. Patients with 50% or more cellular crescents and those with less extensive cellular crescents plus moderate to severe interstitial fibrosis were at markedly increased risk for doubling serum creatinine compared to those who lacked these histologic features (P < 0.0001). Azotaemia, anaemia, hypocomplementaemia, hypertension, tubular atrophy and glomerular sclerosis were also associated with an increased probability of renal function deterioration. Serum creatinine, haematocrit, race, and kidney pathology data emerged as independent predictors of renal insufficiency. Black patients in this study were more likely than the others to have high-risk histological features, including extensive cellular crescents (> or = 50%) and moderate to severe interstitial fibrosis, prior to randomization. CONCLUSIONS: Combinations of high-risk demographic, clinical and histological attributes identify patients at increased risk for progressive renal function deterioration. Several factors, including the severity of kidney biopsy findings, probably contribute to the poor prognosis of Black patients in this study population.

Adult↗
PubMed1994

Predicting renal outcomes in severe lupus nephritis: contributions of clinical and histologic data.

Despite several years of intense investigation, there continues to be controversy about the value of clinical, demographic and histologic features in prediction of outcomes of lupus nephritis. In addition, contemporary treatments have reduced the risk of progressive renal injury and thus may have altered the prognostic significance of some of these factors. We have therefore re-examined the predictive value of variables previously associated with an increased risk of renal insufficiency by studying 65 patients with severe lupus nephritis treated with intensive regimens of intravenous pulse cyclophosphamide or methylprednisolone. Five clinical features at study entry were each associated with an increased probability of doubling the serum creatinine: age greater than 30 years, Black race, hematocrit less than 26%, serum creatinine greater than 2.4 mg/dl, and C3 complement less than 76 mg/dl. By multivariate survival analysis, serum creatinine, hematocrit and race emerged as the strongest set of independent clinical predictors; the other clinical and demographic factors, including age and C3 complement did not contribute significantly to outcome predictions in the context of these three variables. Renal biopsy evaluation offered additional prognostic information and showed that patients with severe active and chronic histologic changes were at increased risk for developing renal insufficiency. The combination of cellular crescents and interstitial fibrosis was particularly ominous. Outcome predictions based on the strongest clinical model (serum creatinine, hematocrit and race) were significantly enhanced by the addition of renal pathology data. Consideration of these prognostic factors may contribute to decisions regarding the type and intensity of immunosuppressive therapy for patients with lupus nephritis.

Adult↗
PubMed1994

Gene targeting in normal somatic cells: inactivation of the interferon-gamma receptor in myoblasts.

Gene targeting in somatic cells represents a potentially powerful method for gene therapy, yet with the exception of pluripotent mouse embryonic stem (ES) cells, homologous recombination has not been reported for a well characterized, non-transformed mammalian cell. Applying a highly efficient strategy for targeting an integral membrane protein--the interferon gamma receptor--in ES cells, we have used homologous recombination to target a non-transformed somatic cell, the mouse myoblast, and to compare targeting efficiencies in these two cell types. Gene-targeted myoblasts display the properties of normal cells including normal morphology, ability to differentiate in vitro, stable diploid karyotype, inability to form colonies in soft agar and lack of tumorigenicity in nude mice.

Animals↗
PubMed1994

A pilot study of anti-CD5 ricin A chain immunoconjugate in systemic lupus erythematosus.

OBJECTIVE: To determine the safety and clinical and biological effects of a murine monoclonal anti-CD5 ricin A chain immunoconjugate (CD5 Plus) in patients with systemic lupus erythematosus (SLE). METHODS: An open label phase I study of CD5 Plus. A dose of 0.1 mg/kg was administered intravenously on 5 consecutive days. A second course of immunoconjugate was given to patients who failed to show any clinical response one to 2 months later. RESULTS: Six patients (4 with glomerulonephritis and 2 with thrombocytopenia) were studied. Improvement was documented in 2 patients with nephritis; no effect on thrombocytopenia was observed. Adverse effects were mild and transient. Relative to pretreatment lymphocyte counts, the mean reduction in CD3+ T cell count was 69% at 2 weeks, 32% at one month, and 34% at 6 months following initial treatment. A comparable decrease in all subpopulations of mature T cells was noted, using a variety of surface markers, including CD4 and CD8. The mean percentage of T cells expressing the activation markers HLA-DR and interleukin 2R (IL-2R) was high before treatment, and remained so. There was a transient decrease in CD5+ B cells, but no persistent depletion of total B cell numbers. There was no consistent change in natural killer cell populations. CONCLUSION: Anti-CD5 ricin A chain immunoconjugate is well tolerated in patients with SLE, causes modest T cell depletion which may persist for months, and may have some clinical efficacy in lupus nephritis.

Antibodies, Monoclonal↗
PubMed1993

Risk for sustained amenorrhea in patients with systemic lupus erythematosus receiving intermittent pulse cyclophosphamide therapy.

OBJECTIVE: To determine the risk for secondary amenorrhea after pulse cyclophosphamide therapy in premenopausal women with systemic lupus erythematosus. DESIGN: Controlled, retrospective clinical study. SETTING: Government referral-based research hospital. PATIENTS: Thirty-nine women younger than 40 years treated with pulse cyclophosphamide therapy for active lupus nephritis or neuropsychiatric lupus. Sixteen women who received pulses of intravenous methylprednisolone were controls. INTERVENTIONS: Sixteen patients received pulse cyclophosphamide (0.5 to 1.0 g/m2 body surface area) monthly for a total of 7 doses (short-CY), and 23 patients received 15 or more doses (long-CY). Control patients were treated with monthly pulses of methylprednisolone (1.0 g/m2) for a total of nine doses. MEASUREMENTS: Rates of amenorrhea were evaluated according to duration of treatment (number of doses) and age at the initiation of pulse therapy. RESULTS: Two of 16 patients (12%) in the Short-CY group and 9 of 23 (39%) in the long-CY group developed sustained amenorrhea (P = 0.07). Rates of sustained amenorrhea (short- and long-CY) according to age at the start of pulse therapy were: < or = 25 years, 2/16 (12%); 26 to 30 years, 4/15 (27%); > or = 31 years, 5/8 (62%) (P = 0.04). The increased risk for sustained amenorrhea in patients treated with long-CY was most evident in patients older than 25 years (short-CY [2/12] compared with long-CY [7/11]; P = 0.03). Three other patients with short-CY had reversal of amenorrhea fewer than 12 months after cessation of therapy. Amenorrhea was not observed in any of the 16 control patients. CONCLUSIONS: Intermittent pulse cyclophosphamide therapy in patients with systemic lupus erythematosus is associated with sustained amenorrhea, which is related to both age and number of doses of cyclophosphamide.

Adult↗
PubMed1993

Germ-line transmission and expression of a human-derived yeast artificial chromosome.

Introduction of DNA fragments, hundreds of kilobases in size, into mouse embryonic stem (ES) cells would greatly advance the ability to manipulate the mouse genome. Mice generated from such modified cells would permit investigation of the function and expression of very large or crudely mapped genes. Large DNA molecules cloned into yeast artificial chromosomes (YACs) are stable and genetically manipulable within yeast, suggesting yeast-cell fusion as an ideal method for transferring large DNA segments into mammalian cells. Introduction of YACs into different cell types by this technique has been reported; however, the incorporation of yeast DNA along with the YAC has raised doubts as to whether ES cells, modified in this way, would be able to recolonize the mouse germ line. Here we provide, to our knowledge, the first demonstration of germ-line transmission and expression of a large human DNA fragment, introduced into ES cells by fusion with yeast spheroplasts. Proper development was not impaired by the cointegration of a large portion of the yeast genome with the YAC.

Animals↗
PubMed1992

Controlled trial of pulse methylprednisolone versus two regimens of pulse cyclophosphamide in severe lupus nephritis.

Pulse cyclophosphamide is more effective than prednisone alone in preventing renal failure in lupus nephritis. We undertook a randomised, controlled trial to find out whether pulse methylprednisolone could equal pulse cyclophosphamide in preserving renal function in patients with lupus nephritis, and whether there was a difference between long and short courses of pulse cyclophosphamide in preventing exacerbations. 65 patients (60 female, 5 male; median [range] age 29 [10-48] years) with severe lupus nephritis were assigned randomly to monthly pulse methylprednisolone for 6 months (25 patients), monthly pulse cyclophosphamide for 6 months (20), or monthly cyclophosphamide for 6 months followed by quarterly pulse cyclophosphamide for 2 additional years (20). Patients treated with pulse methylprednisolone had a higher probability of doubling serum creatinine than those treated with long-course cyclophosphamide (p less than 0.04). Risk of doubling creatinine was not significantly different between short and long course cyclophosphamide. However, patients treated with short-course cyclophosphamide had a higher probability of exacerbations than those treated with long-course cyclophosphamide (p less than 0.01). An extended course of pulse cyclophosphamide is more effective than 6 months of pulse methylprednisolone in preserving renal function in patients with severe lupus nephritis. Addition of a quarterly maintenance regimen to monthly pulse cyclophosphamide reduces the rate of exacerbations.

Adolescent↗
PubMed1992

Combined use of cyclosporine and ketoconazole in the treatment of endogenous uveitis.

Ten patients with endogenous uveitis were in clinical remission attributable to treatment with cyclosporine and prednisone. After the cyclosporine dose was reduced by two thirds, these patients were randomly assigned to treatment with or without ketoconazole, a potent inhibitor of cytochrome P-450, in a double-masked placebo-controlled study. The dose was reduced over three days. During a three-month follow-up, no patients treated with ketoconazole had a relapse of uveitis, while four of six (66%) control subjects had a flare-up. Toxicity in the ketoconazole-treated group was limited to a transient decrease in glomerular filtration rate (20% from baseline) at one month in two of six (33%) patients. Renal function was stabilized by further reduction of the cyclosporine dose.

Autoimmune Diseases↗
PubMed1992

NIH conference. Membranous nephropathy.

Membranous nephropathy is a worldwide problem that accounts for about 20% of the cases of the adult-onset nephrotic syndrome. This disease places many patients at risk for both end-stage renal failure and the complications of hyperlipidemia. Immune-mediated injury to the glomerular capillary wall in patients with membranous nephropathy is characterized by subepithelial immune complex formation and generation of the membrane attack complex of complement. Glomerular capillary hypertension, hyperlipidemia, and possibly cytokines could contribute to the glomerular sclerosis seen in the advanced stages of the disorder. In some cases, production of pathogenic antibody can be suppressed by treating the underlying condition. The mechanisms of action of immunosuppressive agents are being investigated and treatments are being tested in clinical trials to optimize the balance of efficacy and toxicity. Alternate-day treatment with corticosteroids is often recommended for nephrotic patients with idiopathic membranous nephropathy, but this approach has not been proved beneficial. Ongoing studies are evaluating whether cytotoxic drugs or cyclosporin A combined with prednisone is more effective than treatment with corticosteroids alone. Lipid-lowering drug therapy is warranted in cases of the persistent nephrotic syndrome to avert the cardiovascular sequelae of hyperlipidemia.

Animals↗
PubMed1992

Hydrated clearance of gadolinium-DTPA as a measurement of glomerular filtration rate.

Technetium (99mTc)-diethylene triamine pentaacetic acid (DTPA) hydrated clearance studies are accurate for determining GFR but require special facilities for handling and measuring samples. We investigated the potential of a non-radioactive paramagnetic analog, Gadolinium (Gd)-diethylene triamine pentaacetic acid (DTPA), an approved NMR contrast agent, as a glomerular filtration marker. Instead of relying on the radioactivity of technetium, this test is based on the fact that gadolinium induces alterations in the NMR T1 relaxation times in blood and urine samples. Ninety patients underwent simultaneous determinations of GFR using 1 mCi of Tc-DTPA and 0.05 mmol/kg Gd-DTPA (Berlex Labs) IV. The patients were hydrated with oral and intravenous fluid. Following a one hour equilibrium period, three or four consecutive urine collections were obtained; plasma samples were acquired at the beginning and end of each approximately 20-minute interval. 99mTc-DTPA radioactivity was determined with a scintillation counter. T1 relaxation times were measured on a 10 MHz NMR spectrometer. These were converted to Gd-DTPA concentration by comparison with standard solutions. The Gd-DTPA derived GFR closely approximated the 99mTc-DTPA derived GFR which ranged from 15 to 147 ml/min. The equation and correlation coefficient of the regression line is y = 1.04 x -2.2, r = 0.94. Thus, Gd-DTPA is a safe, non-radioactive indicator of GFR that may provide an alternative renal clearance method for clinical studies of progressive renal disease and nephrotoxicity.

Contrast Media↗
PubMed1992

Human immunodeficiency virus (HIV) and HIV infected cells in saliva and salivary glands of a patient with systemic lupus erythematosus.

A young woman with systemic lupus erythematosus (SLE) was infected with human immunodeficiency virus 1 (HIV-1) and about 6 years later developed persistent bilateral parotid gland enlargement. It was unclear whether this represented salivary gland involvement as a component of her SLE (secondary Sjögren's syndrome) or the initial clinical manifestation of her HIV-1 infection. HIV proviral DNA was found in individual salivary glandular secretions and in whole saliva. Additionally, cells positive for HIV RNA were isolated from whole saliva. A parotid gland biopsy revealed infiltrating lymphocytes containing large amounts of HIV RNA.

Adult↗
PubMed1991

Functional MR of the kidney.

A bolus injection of Gadopentetate Dimeglumine with dynamic gradient echo MR imaging has allowed for the visualization of normal and abnormal renal function. Following an injection of gadopentetate dimeglumine, NMR T1 relaxation times obtained on serial collections of serum and urine at timed intervals were used to derive the glomerular filtration rate. The merger of dynamic contrast-enhanced MRI with an in vitro NMR-derived GFR provides for assessment of renal function without the use of radioactive agents.

Animals↗
PubMed1990

Expression of transforming growth factor-beta 1 and beta 2 in rat glomeruli.

The transforming growth factors-beta are potent modulators of cell growth and extracellular matrix metabolism in most types of cultured cells. The distribution and functions of TGF-beta in vivo are less well known. We utilized several different techniques including northern blots, a CCl-64 cell growth inhibition assay, and sandwich enzyme-linked immunosorbent assays (SELISA) to examine the expression of TGF-beta 1 and TGF-beta 2 in rat glomeruli. High levels of TGF-beta 1 mRNA and protein were found in glomeruli (56 +/- 22 ng TGF-beta 1/g tissue). These levels were several-fold higher than those present in whole kidney (10 +/- 5 ng/g). TGF-beta 2 mRNA was present in glomeruli but was not detected in whole kidney. TGF-beta 2 concentrations by SELISA were 19 +/- 8 ng TGF-beta 2/g in glomeruli and less than 5 ng/g in whole kidney. Since TGF-beta has such marked effects on cell growth, we also examined whether alterations in TGF-beta expression were associated with the renal hypertrophy which follows unilateral nephrectomy. Expression of TGF-beta 1 mRNA decreased in glomeruli following nephrectomy. However, this was not associated with a significant fall in glomerular TGF-beta 1 protein concentration. Whole kidney levels of TGF-beta 1 and its mRNA were unchanged following nephrectomy. Similar results were obtained for TGF-beta 2. Our data document the presence of high concentrations of TGF-beta 1 and beta 2 and their corresponding mRNAs in normal rat glomeruli. These results suggest that TGF-beta may play important regulatory roles in the normal glomerulus.

Animals↗
PubMed1989

Renal toxicity of interleukin-2 administration in patients with metastatic renal cell cancer: effect of pre-therapy nephrectomy.

Systemic administration of interleukin-2 and lymphokine-activated killer cells is a new approach to the immunotherapy of advanced cancer. Metastatic renal cell cancer is one of the histological types of tumors particularly susceptible to this treatment approach although renal toxicity often is a dose-limiting side effect. We compared the renal functional changes observed during interleukin-2 therapy in 52 consecutive patients with advanced renal cancer to that of 83 consecutive patients with metastatic nonrenal cancer. Of the 52 patients with renal cancer 41 had recently undergone nephrectomy. The over-all peak serum creatinine values and the percentage increase of serum creatinine over baseline for all patients studied were significantly higher in cycle 2 of interleukin-2 therapy than in cycle 1: 3.8 +/- 0.2 versus 2.6 +/- 0.1 mg. per dl. and 241.7 +/- 16.5 versus 140.3 +/- 11.0 per cent, respectively. In patients with pre-therapy serum creatinine values of 0.4 to 0.9 mg. per dl. there were no significant differences in the mean peak serum creatinine nor in the percentage increase over baseline between renal and nonrenal cancer patients during cycle 1. In cycle 2 of therapy these values were higher in the renal cancer group (3.6 +/- 0.8 versus 2.4 +/- 0.2 mg. per dl. and 310.4 +/- 103.5 versus 214 +/- 30.4 per cent, respectively) but they did not reach statistical significance (P2 = 0.08 and 0.25, respectively). Renal and nonrenal cancer patients with pre-therapy serum creatinine levels of 1.0 to 1.4 mg. per dl. achieved similar high values in cycle 2 of interleukin-2 therapy (3.9 +/- 0.3 versus 3.9 +/- 0.4 mg. per dl. and 222.7 +/- 23.2 versus 248.7 +/- 33.5 per cent, respectively), although the initial increase (cycle 1) was higher in the renal cancer patients (3.3 +/- 0.3 versus 2.4 +/- 0.2 mg. per dl. and 172.3 +/- 25.9 versus 116.1 +/- 18.0 per cent, respectively). Baseline serum creatinine greater than or equal to 1.5 mg. per dl. was associated with an over-all higher peak serum creatinine and higher percentage increase of serum creatinine over baseline than that below 1.5 mg. per dl. baseline: 4.4 mg.per dl. and 171.1 +/- 36.3 per cent in cycle 1 and 6.5 +/- 0.7 mg. per dl. and 296.1 +/- 44.0 per cent in cycle 2, respectively (p less than 0.01). There was no association between peak serum creatinine and interval from nephrectomy to interleukin-2 therapy.(ABSTRACT TRUNCATED AT 400 WORDS)

Carcinoma, Renal Cell↗