Pharmacokinetics of rosuvastatin in patients with end-stage kidney disease undergoing peritoneal dialysis.

Patients undergoing dialysis treatment have a high incidence of dyslipidemia. Rosuvastatin is a potent statin drug that improves overall lipid profiles in dyslipidemic patients. However, the pharmacokinetics of rosuvastatin has not been studied in patients with end-stage kidney disease undergoing chronic peritoneal dialysis (PD). The goals of this study are to determine the pharmacokinetics and tolerability of a single oral dose of rosuvastatin in patients undergoing continuous ambulatory PD (CAPD). This was a nonrandomized, open-label, 1-week trial. Ten stable PD patients were given a single oral dose of rosuvastatin (10 mg). Serial blood samples were obtained over the next 48 hours, and the patients were followed for 1 week while they underwent CAPD. Rosuvastatin plasma concentration peaked (Cmax) at 3.68 +/- 2.3 ng/ml (geometric mean), 4.5 hours (median; range 2 - 6 hours) after oral dosing. The plasma concentration of rosuvastatin was 0.44 +/- 0.23 ng/ml at 24 hours (C24) and 0.14 +/- 0.07 ng/ml, with levels below the detectable range in 5 of 10 subjects, at 48 hours (C48). The area under the plasma concentration-time from 0 to 48 hours (AUC0-48) was 32.6 +/- 1.6 ng/ml/h. These pharmacokinetic profiles of rosuvastatin in CAPD patients are very similar to those observed in healthy volunteers, but different from patients with Stages 4 - 5 chronic kidney disease. A single oral dose of rosuvastatin was well tolerated in this small number of patients. We conclude that pharmacokinetic profiles of rosuvastatin in patients undergoing CAPD are similar to those observed in healthy volunteers. These findings suggest that a lower dose of rosuvastatin (<<= 10 mg) may be administered in CAPD patients without dose adjustment.

Constitutive and inducible expression of CYP enzymes in immortal hepatocytes derived from SV40 transgenic mice.

1. The expression of liver-specific transcription factors and cytochrome P450 (CYP) enzymes have been studied in three new hepatocyte-like cell lines derived from SV Delta 202 transgenic mice: AMH-Delta 202 (adult mouse hepatocytes), TAMH-Delta 202 (tumour-derived adult mouse hepatocytes) and NMH-Delta 202 (newborn mouse hepatocytes). 2. mRNA levels of liver-enriched transcription factors such as D-element binding protein (DBP), liver-enriched transcription activating protein (LAP) and the hepatic nuclear factors (HNF) 1, 2 and 3 in all Delta 202 transgenic hepatocyte lines were similar to those in the wild-type liver and in primary mouse hepatocytes. 3. Analysis of basal CYP activities and testosterone metabolism revealed that Delta 202 cells showed higher similarities to mouse hepatocytes than Hepa 1c1c7 hepatoma cells. All three Delta 202 cell lines exhibited substantial active CYP1A1/2, CYP2A4/5 and CYP3A11 activities and lower levels of CYP2B, CYP2C and CYP2E1 activities. 4. The Delta 202 cells also responded to model inducers. 3-Methylcholanthrene induced CYP1A1/2 (7-ethoxyresorufin O-deethylation); phenobarbital induced CYP2B (7-benzoxyresorufin O-debenzylation), CYP2A4/5 (testosterone 7alpha -hydroxylation) and CYP3A11 (testosterone 6beta -hydroxylation); and rifampicin and dexamethasone induced CYP3A11 activities in the three Delta 202 cell lines, whereas only AMH-Delta 202 cells reproduced to a limited extent the response of CYP2E1 to ethanol observed in hepatocytes. 5. The results suggest that generation of hepatocyte lines from transgenic animals constitutes a successful approach to obtain in vitro models alternative to primary hepatocytes for drug metabolism and CYP inducibility studies.

Association of endotoxemia and production of antibodies against endotoxins after multiple injuries.

BACKGROUND: Endotoxemia after injury has been a controversial issue. Endotoxins stimulate the innate and adaptive immune system. OBJECTIVE: To investigate endotoxemia and its effects on the production of antiendotoxin antibodies of cultured mononuclear cells of patients with multiple injuries. METHODS: Blood samples of 20 patients with multiple injuries were collected up to 12 days after trauma. The endotoxin concentration was measured in the plasma, and mononuclear cells were isolated and cultured. Specific antibodies against two lipopolysaccharides, one lipid A preparation, and alpha-hemolysin of Staphylococcus aureus were measured in the cell culture supernatant by an enzyme-linked immunosorbent assay. RESULTS: Endotoxemia peaked at admission of the patients, decreasing thereafter to almost normal values within 5 days. Isolated mononuclear cells synthesized antibodies against all tested antigens with a peak at or between day 5 and day 7. The increase was significant for immunoglobulin (Ig)A and IgM specific to all endotoxins tested and for IgA specific to alpha-hemolysin. However, there were no significant changes of the concentrations of total IgM, IgA, and IgG. All specific IgG remained unaffected. CONCLUSION: Patients with multiple injuries initially have temporary endotoxemia. Endotoxin may be suggested as a stimulator of the synthesis of antiendotoxin antibodies, in particular of the IgA and IgM class in patients with multiple injuries.

C1-esterase inhibitor and its effects on endotoxin-induced leukocyte adherence and plasma extravasation in postcapillary venules.

BACKGROUND: C1-esterase inhibitor (C1-INH) has been shown to have beneficial effects in patients with sepsis. However, the microcirculatory effects of C1-INH during sepsis are unknown. This study investigated the influence of C1-INH on leukocyte-endothelial cell adhesion, vascular leakage, and venular microhemodynamics in postcapillary venules of rat mesentery during endotoxemia. METHODS: Thirty-two anesthetized Wistar rats randomly received 1 of 4 treatments: pretreatment with infusion of C1-INH in a concentration of 7.5 U.kg-1 body weight (C1-INH-7.5 group, n = 8) or in a concentration of 15 U.kg-1 body weight (C1-INH-15 group, n = 8) followed by continuous infusion of Escherichia coli lipopolysaccharide (LPS). The LPS group (n = 8) was pretreated with saline solution 30 minutes before LPS infusion. The control group (n = 8) received equivalent amounts of saline infusion. Leukocyte adherence, red blood cell velocity, and vessel diameters in postcapillary venules of rat mesentery were determined every 60 minutes during a period of 120 minutes using in vivo videomicroscopy. Vascular permeability was determined by measuring the extravasation of fluorescence-labeled albumin. Venular wall shear rate was calculated from mean red blood cell velocity and vessel diameter. RESULTS: LPS infusion induced a decrease in venular wall shear rate and an increase in leukocyte adherence and vascular permeability in postcapillary venules of rat mesentery. All microcirculatory disturbances were attenuated by pretreatment with C1-INH, showing no significant difference between the 2 concentrations. CONCLUSIONS: Pretreatment with C1-INH attenuates endotoxin-induced leukocyte adherence and macromolecular leakage in postcapillary venules of rat mesentery, indicating that complement inhibition might be a therapeutic tool in the treatment of sepsis.

Influence of C1-esterase inhibitor on tissue oxygenation of jejunal mucosa during endotoxemia.

BACKGROUND: The complement system has been shown to play an important role in the pathogenesis of microcirculatory disturbances in trauma and sepsis. The intestinal mucosa is the most susceptible portion of the gut to impaired perfusion and oxygen delivery. The objective of this study was to investigate the effects of C1-esterase inhibitor (C1-INH) on arterial oxygenation (PaO2) and tissue oxygenation (PtiO2) of jejunal mucosa during endotoxemia. METHODS: Eighteen anesthetized and ventilated rats were laparotomized and a jejunal portion was exteriorized and fixed on a plexiglass stage. The jejunum was punctured and a Clark type microcatheter PO2 probe and a micro thermocouple were placed on the mucosa in order to measure PtiO2. The animals were randomly assigned to receive one of the three treatments: infusion of Escherichia coli lipopolysaccharides (LPS) without C1-INH pretreatment (LPS group); or infusion of LPS with C1-INH pretreatment (C1-INH group); the control group (n = 6) without treatment of either C1-INH or LPS. The mean arterial pressure (MAP), heart rate (HR), PaO2 and PtiO2 were measured at baseline, 60 and 120 min after induction of endotoxemia. RESULTS: Hemodynamic parameters (MAP, HR) in all the three groups showed no significant changes during the study period. PaO2 significantly decreased in the LPS group. This decrease could be attenuated by pretreatment with C1-INH. The mucosal PtiO2 of the jejunum in the control group remained stable. It significantly decreased in the LPS and in the C1-INH groups without showing a significant difference after 120 min of endotoxemia. CONCLUSIONS: Pretreatment with C1-INH was able to diminish a decrease in PaO2 during endotoxemia, indicating that pulmonary injury was attenuated. Endotoxin-induced tissue hypoxia of the intestinal mucosa could not be prevented suggesting a minor involvement of complement activation in this pathophysiological process.

Interleukin-6 predicts hypoalbuminemia, hypocholesterolemia, and mortality in hemodialysis patients.

Low serum albumin and low serum cholesterol levels are among the most consistent predictors of mortality in patients with end-stage renal disease (ESRD) undergoing hemodialysis. Hypoalbuminemia is often interpreted as a marker of poor nutrition, but serum albumin and cholesterol levels can also be low as part of a cytokine-mediated acute-phase reaction to acute or chronic inflammation. Here we report the results from a 900-day prospective study designed to determine whether tumor necrosis factor-alfa (TNF-alpha) and interleukin-6 (IL-6) predict serum albumin and cholesterol levels and mortality in a group of 90 ambulatory, adult hemodialysis patients with no acute infection, hospitalization or surgery, and no known acquired immunodeficiency syndrome (AIDS), malignancy, or liver disease. Measurable levels of TNF-alpha and/or IL-6 were found in 89 of 90 patients. Significant relationships were found between TNF-alpha and IL-6 and the degree of hypoalbuminemia and dyslipoproteinemia. IL-6 was the strongest predictor of mortality in univariate and multivariate analysis, followed by age, albumin level, and body mass index (BMI). Although the cause of hypercytokinemia was not addressed in this study, the data support the view that hypoalbuminemia and hypocholesterolemia are negative acute-phase responses to inflammatory stimuli. These results suggest that efforts to identify the nature of the stimuli for cytokine production and to lower cytokine levels in hemodialysis patients might be effective in improving the survival of patients undergoing hemodialysis.

Long-term expression of differentiated functions in hepatocytes cultured in three-dimensional collagen matrix.

Hepatocytes entrapped in collagen gel and cultured in serum-free conditions survived longer than cells cultured on plastic (5 days vs. 3 weeks), showed fewer signs of early cell senescence (no increase in c-fos oncoprotein expression), and maintained the expression of differentiated hepatic metabolic functions over a longer period of time. Cells cultured in collagen gels retained their ability to respond to hormones. The insulin-stimulated glycogen synthesis rate remained fairly constant during 18 days in culture (between 5.4 +/- 0.37 and 9 +/- 2.7 nmol glucose/h/microg DNA). Collagen-cultured hepatocytes recovered glycogen stores to levels similar to those found in liver, or in hepatocytes isolated from fed rats. Urea synthesis from ammonia remained stable for more than 2 weeks (average value, 23 +/- 4 nmol urea/h/microg DNA). The rate of albumin synthesis in collagen-entrapped cells was maintained above the day-1 level during 18 days in culture. Cells showed high levels of glutathione (GSH) (1,278 +/- 152 pmol/microg DNA). Biotransformation activities CYP4501A1, CYP4502A2, CYP4502B1, and CYP4503A1 remained fairly stable in collagen-cultured hepatocytes. CYP4502E1 and CYP4502C11 decreased but were still measurable after 18 days. After 4 days in culture, GST activity returned to levels observed in isolated hepatocytes. In contrast with plastic cultures, cells responded to CYP450 inducers (methylcholanthrene for CYP4501A1, CYP4501A2, and glutathione-transferase, and ethanol for CYP4502E1) for more than 2 weeks. CYP4501A1, CYP4501A2, and glutathione-transferase A2 (GST A2) induction was preceded by an increase in specific mRNA, while the effects on CYP4502E1 seemed to be at a posttranslational level. Analysis of the expression of relevant hepatic genes by reverse Northern and semiquantitative reverse transcriptase-polymerase chain reaction (RT-PCR) revealed that culturing hepatocytes in collagen gels results in a sustained higher expression of key liver transcription factor genes DBP, C/EBP-alpha and -beta, and HNF-1 and -4, as well as specific liver enzyme genes (phosphoenol pyryvate carboxykinase, and carbamoylphosphate-synthetase I).

Effect of nifedipine on renal allograft function and survival beyond one year.

We previously reported that a calcium channel blocker supplemented immunosuppression produced excellent patient and graft survival rates in cadaveric kidney transplantation. We report here the long term outcome of patients treated with nifedipine-supplemented triple immunosuppression as compared with those of historical controls who were treated similarly without nifedipine. Study subjects included 111 patients transplanted in 1990-1994, treated with nifedipine and triple immunosuppression and with functioning grafts for more than one year (Nifedipine group). The results of cyclosporine (CyA) dose, blood pressure (BP), serum creatinine (Cr), and actuarial graft survival rate (GSR) up to 5 years posttransplant in these patients were compared with those of 52 patients transplanted in 1985-1990, treated similarly without calcium channel blockers (Control group). Donor sources, gender ratio, age distribution, causes of end stage renal disease, incidence of hypertension prior to transplantation and incidence of rejection in the first year between the groups were comparable. Throughout the study period the Nifedipine group had significantly lower serum Cr (1.5 +/- 0.7 vs. 1.8 +/- 0.7 mg/dl) and higher GSR (93.8% vs. 88% at 5 years) than the Control group. BP was comparable despite higher CyA doses in the Nifedipine group (4.3 +/- 1.1 vs. 3.3 +/- 1.1 mg/kg/day). We conclude that nifedipine is beneficial in improving long-term graft function and survival in kidney transplant recipients by mitigating CyA associated renal injury.

Poly[allylamine hydrochloride] (RenaGel): a noncalcemic phosphate binder for the treatment of hyperphosphatemia in chronic renal failure.

Dietary phosphate restriction and the oral administration of calcium and aluminum salts have been the principal means of controlling hyperphosphatemia in individuals with end-stage renal disease over the past decade. Although relatively well-tolerated, a large fraction of patients treated with calcium develop hypercalcemia, particularly when administered concurrently with calcitriol, despite a lowering of the dialysate calcium concentration. We evaluated the efficacy of cross-linked poly[allylamine hydrochloride] (RenaGel; Geltex Pharmaceuticals, Waltham, MA), a nonabsorbable calcium- and aluminum-free phosphate binder, in a randomized, placebo-controlled, double-blind trial of 36 maintenance hemodialysis patients followed over an 8-week period. RenaGel was found to be as effective as calcium carbonate or acetate as a phosphate binder. The reduction in serum phosphorus was significantly greater after 2 weeks of treatment with RenaGel (6.6 +/- 2.1 mg/dL to 5.4 +/- 1.5 mg/dL) compared with placebo (7.0 +/- 2.1 mg/dL to 7.2 +/- 2.4 mg/dL; P = 0.037). There was no significant change in serum calcium concentration in either treatment group. The total serum cholesterol and low-density lipoprotein cholesterol fraction were significantly reduced in RenaGel-treated patients compared with placebo-treated patients (P = 0.013 and P = 0.003, respectively) without a concomitant reduction in high-density lipoprotein cholesterol (P = 0.93). There was no difference among recipients of RenaGel and placebo in terms of adverse events. RenaGel is a safe and effective alternative to oral calcium for the management of hyperphosphatemia in end-stage renal disease.

Long-term preservation of islets of Langerhans in hydrophilic macrobeads.

Several obstacles have hindered the successful transplantation of islets of Langerhans to human patients in efforts to cure type I diabetes mellitus. One problem is the necessity for short- and long-term storage of islets after isolation and before transplantation. Current long-term storage methods, such as incubation in a physiological medium and cryopreservation, are suboptimal, resulting in significant loss of viable islet mass or function. Better storage methods are needed. In this study we examined the long-term storage of rat islets in macrobeads composed of agarose and collagen. Islets isolated from Wistar-Furth rats were placed into macrobeads (1000 islets/macrobead) and maintained in culture for periods of up to 189 days at 37 degrees C. Insulin released from the cultured macrobeads remained constant for periods of at least 154 days. In one group, insulin release was 1050 mU/24 hr/4 beads on day 3 and 1040 mU/24 hr/4 beads on day 154. In another group, insuling release was 1305 Xenotransplantation of Wistar Furth islet macrobeads, stored for 10 to 112 days at 37 degrees C, degrees C into 42 B6AF/1 mice with streptozotocin-induced diabetes resulted in a return to euglycemia in the recipients within 24 hr. Thereafter, euglycemia was maintained for more than 100 days in 32/42 of the recipients, and removal of the macrobeads caused a return to hyperglycemia within 48 hr in all animals. In addition, a group of 7 mice receiving macrobeads containing 1000 islets stored for 84 days had normal glucose tolerance tests (compared with those of 7 nontreated, nontransplanted mice with streptozotocin-induced diabetes and 7 normal mice), demonstrating that the islets in the macrobeads were functioning as they would in an intact pancreas. Finally, 5 macrobeads transplanted after initial storage of 112 days, removed from the first recipient after 100 days or more, stored again for 4 days in vitro, and retransplanted into 5 other diabetic mice also restored and maintained euglycemia for at least 45 days. Our results indicate that collagen-agarose macrobeads are capable of preserving rat pancreatic islets for extended periods without loss of in vitro insulin release capability or ability to achieve and maintain euglycemia in vivo. As such they should be useful for human islet transplantation efforts.

Intragraft expression of IL-10 messenger RNA: a novel correlate of renal allograft rejection.

A major conceptual advance is the formulation that type I cytokines (such as IL-2 and IFN-gamma) enhance cellular immunity and are host-protective, and that type II cytokines (such as IL-4 and IL-10) dampen cellular immunity and facilitate the progression of infection. We have explored the intragraft expression of type I and type II cytokines during human renal allograft rejection. RNA was isolated from 98 allograft biopsies, and reverse transcription-PCR was used to amplify and identify intragraft expression of mRNA encoding IL-2, IFN-gamma, IL-4, or IL-10. Intragraft expression of IL-7 mRNA and TGF-beta 1 mRNA was also investigated. Our investigation demonstrated that: (a) intragraft expression of IL-10 mRNA and IL-2 mRNA are significant correlates of acute rejection; (b) IL-4, IL-7, IFN-gamma and TGF-beta 1 mRNA expression do not correlate with acute rejection; and (c) IL-10 does not prevent in vivo expression of IFN-gamma, IL-2, IL-7, or TGF-beta 1. Our studies identify, for the first time, a significant association between intragraft IL-10 mRNA expression and acute rejection, and suggest that treatment strategies capable of constraining IL-10 expression might be of value in the prevention of acute rejection.

Retrievable, replaceable, macroencapsulated pancreatic islet xenografts. Long-term engraftment without immunosuppression.

Prevention of rejection and prolongation of graft survival are critical to achieving successful islet cell transplantation. Various techniques have been utilized to prolong graft survival. Recently, protection of pancreatic islets from host immune mechanisms by isolating the islets in artificial membranes has emerged as an attractive alternative to the use of immunosuppression. In this Rapid Communication, we describe a novel method for macroencapsulation of rat islets in hydrophilic macrobeads made with various combinations of agarose, collagen, and Gelfoam. Encapsulated xenotypic islets were placed intraperitoneally in mice in which diabetes was induced by streptozotocin. The encapsulated xenografts maintained normoglycemia > 170 days. Recipients mice had normal glucose tolerance tests, which indicates that the islets in the macrobeads were functioning as they would in an intact pancreas. Macrobeads retrieved up to 103 days after transplantation showed no evidence of tissue reaction or local inflammation. These retrieved macrobeads could also be retransplanted and replaced. Our studies indicate that the agarose-collagen/Gelfoam macrobeads we have developed serve both to protect islet xenografts from rejection and to provide a microenvironment in which the islets maintain and support their normal function in vivo. Because they may be retrieved after implantation and replaced, these macrobeads may be suitable for human clinical islet cell xenotransplantation.

Long term results of subtotal parathyroidectomy in patients with end-stage renal disease.

This is a retrospective, clinical study evaluating the long-term outcome of subtotal parathyroidectomy (PTX) in 60 patients with chronic renal failure and severe secondary hyperparathyroidism. Patients were 41 +/- 2 years old (mean +/- SE) at the time of PTX, and followed for 69 +/- 6 months since the procedure. At the time of PTX, three patients had chronic renal failure, 53 had been on chronic hemodialysis, and four had received successful kidney transplants. In more than 80 per cent of patients, symptoms of hyperparathyroidism (bone pain and muscle weakness) resolved within weeks, and biochemical signs (hypercalcemia, and high plasma alkaline phosphatase and parathyroid hormone concentrations) returned to normal ranges within a year. Subperiosteal resorption, bone fractures, and soft tissue calcification frequently improved. Osteosclerosis (rugger-jersey spine), cystic bone changes, osteopenia, and vascular calcifications were, however, often unchanged or progressive. Five patients (8%) who had either persistent or recurrent hyperparathyroidism required additional surgical procedures, and two had subsequent improvement. Twelve patients who had aluminum associated bone disease diagnosed later continued to progress with a high incidence of bone fractures and severe osteopenia. Cystic bone changes, especially of the carpal bones, in association with carpal tunnel syndrome, probably representing amyloid bone disease, also did not respond to PTX. In conclusion, PTX is an effective surgical procedure to reverse complications of hyperparathyroidism in patients with end-stage renal disease, provided that other causes of osteodystrophy, such as aluminum or amyloid-associated bone diseases, are adequately excluded. We feel that subtotal PTX, leaving a small remnant in place, is the procedure of choice.

Immunotherapy with anti-CD3 monoclonal antibodies and recombinant interleukin 2: stimulation of molecular programs of cytotoxic killer cells and induction of tumor regression.

Adoptive cellular immunotherapy, infusions of interleukin 2 (IL-2) in conjunction with in vitro-activated killer cells, has brought new hope to patients with cancer. The broad application of this strategy, however, is constrained by the need for repeated leukapheresis and by the labor-intensive process of in vitro activation of cells. Also, current protocols generally use nonphysiological and toxic concentrations of IL-2. Identification of an in vivo stimulant that renders T cells responsive to physiologic concentrations of IL-2 represents a potential improvement over existing approaches. We have determined whether in vivo administration of monoclonal antibodies (mAbs) directed at the T-cell surface protein CD3 induces T-cell responsiveness to IL-2, stimulates cytolytic molecular programs of natural killer cells and cytotoxic T cells, and induces tumor regression. These hypotheses were explored in a murine hepatic MCA-102 fibrosarcoma model. We report that in vivo administration of anti-CD3 mAbs plus IL-2 results in intrahepatic expression of mRNA-encoding perforin, cytotoxic T-cell-specific serine esterase, and tumor necrosis factor alpha. Anti-CD3 mAbs alone or IL-2 alone failed to induce or induced minimal expression of these molecular mediators of cytotoxicity. The anti-CD3 mAbs plus IL-2 regimen also resulted in a significantly smaller number of hepatic metastases and a significantly longer survival time of tumor-bearing mice, compared to treatment with anti-CD3 mAbs alone or IL-2 alone. Our findings suggest that a regimen of anti-CD3 mAbs plus IL-2 is a more effective antitumor regimen compared with anti-CD3 mAbs alone or IL-2 alone and advance an alternative immunotherapy strategy of potential value for the treatment of cancer in humans.

Regulation of new DNA synthesis in mammalian cells by cyclosporine. Demonstration of a transforming growth factor beta-dependent mechanism of inhibition of cell growth.

Immunosuppressants such as cyclosporine are considered to constrain cell growth by preventing the production of growth stimulatory cytokines (e.g., interleukin-2). The possibility exists, however, that CsA and other immunosuppressants might restrain cell growth by promoting the production of growth-inhibitory cytokines. We have explored herein the hypothesis that CsA stimulates the production of transforming growth factor-beta (TGF-beta), and restrains new DNA synthesis in mammalian cells via a TGF-beta-dependent mechanism. To investigate this new postulate independently of an IL-2-dependent mechanism, we utilized, as probes, two mammalian cell lines, distinguished by their sensitivity to growth inhibition by TGF-beta and resistance to IL-2: CCL-64 mink lung epithelial cells (CCL-64 cells) and A-549 human adenocarcinoma cells (A-549 cells). Our experimental approach revealed the following: (A) CsA and not cyclosporine H, an inactive analogue of CsA, mediates growth inhibition of TGF-beta-sensitive cells, CCL-64 cells, and A-549 cells; (B) CsA stimulates these mammalian cells to secrete TGF-beta; and (C) TGF-beta induced by CsA is biologically active in inducing cell growth inhibition (demonstrated by the reversal of CsA-associated inhibition with anti-TGF-beta monoclonal antibodies). Our observations suggest that CsA can regulate cell growth via a TGF-beta-dependent mechanism. Since the multifunctional cytokine TGF-beta can enhance extracellular matrix accumulation as well as augment endothelin production, our findings also advance a mechanism that links, via TGF-beta, the beneficial (immunosuppression) and the harmful (fibrosis, hypertension) consequences of CsA usage.

How well is hypertension controlled in CAPD patients?

UNLABELLED: To determine how well hypertension is controlled in continuous ambulatory peritoneal dialysis (CAPD) patients, we monitored the blood pressure of 31 hypertensive adult CAPD patients treated with antihypertensive agents. Blood pressure (BP) monitoring, using a noninvasive, ambulatory BP monitor, began in the morning and continued every 30-60 min for 24 h (mean 42 readings per patient). The mean BP of all patients over 24 h was 145.6/91.3 mm Hg. In these, 40.5% of systolic BP readings exceeded 150 mm Hg and 50.2% of diastolic readings exceeded 90 mm Hg, suggesting that hypertension was inadequately controlled for a considerable period of time. Diabetic patients had even worse control of BP. Mean BP, heart rates, and BP loads were not different, between daytime or nighttime. These findings suggest that CAPD patients do not preserve the normal circadian rhythm of BP and that their hypertension is not controlled any better during the night than during the day. We repeated BP monitoring after adjustment of antihypertensive medications in 8 patients who had poorly controlled hypertension. Systolic and diastolic BP loads in subsequent studies improved significantly from the first study. IN CONCLUSION: hypertension is suboptimally controlled in most CAPD patients; diabetic patients fare even worse in the control of hypertension; most patients do not preserve the circadian rhythm of BP and there is no difference in the adequacy of hypertension control during the day or at night; assessment of hypertension with ambulatory BP monitoring helps guide therapy and control of hypertension.

Modulation of mouse mesangial cell proliferation by thiourea and lipoxygenase inhibitors.

This paper investigates factors involved in mesangial cell (MC) proliferation by focussing on the proliferative effects of phorbol myristate acetate (PMA) on mouse MC in culture in comparison to those of fetal calf serum (FCS). The potential roles of cyclooxygenase and lipoxygenase products of arachidonic acid metabolism and of hydroxyl radicals on their proliferation are addressed. The results indicate: (1) that PMA can induce proliferation of MC; (2) that inhibition of prostaglandin synthesis by indomethacin does not modify PMA-induced proliferation but enhances the proliferative response to FCS, and (3) that stimulation of MC proliferation by PMA or FCS is inhibited by agents interfering with the generation of products of the lipoxygenase pathway and hydroxyl radical scavengers. The role of lipoxygenase products and reactive oxygen species in MC proliferation deserves further investigation.

Immune stimulatory and anti-tumour properties of haemin.

IL-2 induces tumour regression in some patients with metastatic disease, but the dose of IL-2 is limited by severe toxicity. Agents that increase the expression of IL-2 receptors in the effector cells could be used to improve the effectiveness of IL-2 in mediating its anti-tumour effect. We have reported that haemin increased the expression of IL-2 receptors in human peripheral blood mononuclear cells (PBMC) and synergized with IL-2 in the induction of mitogenicity, cytotoxicity and cytokine production. We now report on haemin-induced immune stimulation and tumour regression in mice. Haemin-induced mitogenicity in mouse splenocytes was potentiated up to two-fold by IL-2. The combination of haemin and IL-2 was also effective in inducing cytotoxicity for natural killer (NK)-resistant target cells. Maximal induction of cytotoxicity was attained at an optimal concentration of haemin of 10 microM. Higher concentrations were less effective. Splenocytes isolated from mice that had been treated in vivo with haemin and IL-2 incorporated twice the amount of 3H-thymidine compared with splenocytes from mice treated with either haemin or IL-2 alone. Cytotoxicity of splenocytes for NK-resistant target cells was not increased following in vivo administration of haemin and IL-2 when fresh splenocytes were tested. Cytotoxicity was enhanced, however, up to five-fold following 48 h in vitro incubation with IL-2. Administration of haemin and IL-2 resulted in a significant decrease (40%) of established hepatic metastases in mice. Either IL-2 or haemin alone at the dose used were ineffective. The anti-tumour effect of haemin and IL-2 was enhanced (63% decrease in metastases) by administration of the thiol compound, N-acetylcysteine. Since haemin can safely be administered to patients, it may represent a new class of biologic response modifiers that could enhance IL-2-mediated anti-tumour effects.