Phase II trial of vorinostat in advanced melanoma.

INTRODUCTION: Vorinostat is a small molecule inhibitor of class I and II histone deacetylases with preclinical activity in melanoma. METHODS: We evaluated 32 patients with advanced primary cutaneous or ocular melanoma in a multi-institutional setting (PMH Phase II Consortium) with continuous daily oral vorinostat 400 mg. The primary endpoint was response rate by RECIST, with time to progression as a secondary endpoint. The study was designed to distinguish a response rate of 20 % from a RR of 5 % and to distinguish a 2 month median progression-free survival (PFS), from one of 3.1 months. The study proceeded to stage 2 following 2 of 16 responses.. We also assessed VEGF, FGF levels, P52 polymorphisms and chromatin-associated proteins as potential biomarkers. RESULTS: Therapy was associated with significant side effects, including fatigue, nausea, lymphopenia, and hyperglycemia. Eleven patients experienced at least one grade 3 or higher adverse event. There were two confirmed PRs in patients with cutaneous melanoma. Sixteen patients had stable disease and 14 patients had progressive disease for best response. In addition, two patients with cutaneous melanoma scored as stable disease had early unconfirmed partial responses with subsequent progression. Patients with stable disease or partial response (n = 18) had a median progression free survival of 5 months. (range 2-12 months). CONCLUSIONS: Vorinostat demonstrated some early responses and a high proportion of patients with stable disease, but did not meet its primary endpoint of response. Different schedules of this agent with BRAF mutation status and markers of histone acetylation could be explored in melanoma.

Aortic aneurysms remain a significant source of morbidity and mortality after use of Dacron(®) patch aortoplasty to repair coarctation of the aorta: results from a single center.

Aortic aneurysm formation after coarctation repair is a serious and life-threatening complication. Repairs using synthetic materials such as Dacron(®) may carry the highest risk of aneurysm formation and rupture. The authors sought to determine the prevalence of aneurysm formation in patients who previously underwent coarctation repair using Dacron(®) patch aortoplasty at their institution. Between 1977 and 1994, 63 patients underwent isolated coarctation repair using Dacron(®) patch aortoplasty. Aneurysms were defined as an aortic dimension 1.5 times that of the aorta at the level of the diaphragm as shown by angiography, computed tomography (CT) scan, or magnetic resonance imaging (MRI). Of 61 early survivors, 29 (47 %) experienced an aneurysm in the area of previous repair. Nine patients (31 %) had spontaneous rupture of the aneurysm, which caused death in seven cases. Elective or emergent aneurysm repair was performed for 20 patients without complication, and 2 patients are being monitored at this writing. The mean interval from patch placement to aneurysm repair was 15 years (range, 4-27 years). Overall freedom from the development of an aortic aneurysm was 97 % at 5 years, 90 % at 10 years, 69 % at 20 years, and 42 % at 25 years. After repair of coarctation using Dacron(®) patch aortoplasty, the risk for aneurysm formation in the area of repair and death from rupture is extremely high. Therefore, in accordance with the 2008 American Heart Association/American College of Cardiology (AHA/ACC) guidelines, all patients with repaired aortic coarctation should undergo either CT or MRI imaging at least every 5 years to assess for aortic aneurysm formation. More frequent imaging should be obtained for patients previously repaired with Dacron(®) patch aortoplasty.

The Supported vs Unsupported Ross in Pediatric Patients: Neoaortic Root and Ventricular Function.

BACKGROUND: The supported Ross is used to mitigate the neoaortic root dilation that has been described with the unsupported Ross. There is limited literature assessing the efficacy of the supported Ross in young patients. In this study, the fate of the neoaortic root was compared in the supported and unsupported Ross procedure in adolescent patients. METHODS: A retrospective review was performed of patients who underwent the Ross procedure between 1996 and 2019. An analysis was conducted of patients aged 10 to 18 years who underwent the supported and unsupported Ross operation, without a Konno enlargement, to assess for longitudinal echocardiographic changes. Given differences in follow-up time, both regression analysis and Mann-Whitney nonparametric tests were used to correct for time from discharge to most recent follow-up. RESULTS: The median follow-up time for supported and unsupported Ross patients without a Konno enlargement was 2.90 years (0.21-13.03 years) and 12.13 years (2.63-19.47 years), respectively. Unsupported Ross patients experienced a higher rate of change per year in the aortic annulus (P = .003 and P = .014) and aortic sinus (P = .002 and P = .002) diameters, respectively. There was no significant difference in the rate of change of end-diastolic left ventricular internal diameter (P = .703 and P = .92) and aortic insufficiency (P = .687 and P = .215) between the supported and unsupported Ross patients. CONCLUSIONS: Progressive dilation of the neoaortic root in unsupported Ross patients is significantly mitigated with the supported Ross with excellent stability. The supported Ross is safe and effective and may play an increasing role in the management of children with aortic disease.

Resting and exercise haemodynamic characteristics of patients with advanced heart failure and preserved ejection fraction.

AIMS: This study aimed to describe haemodynamic features of patients with advanced heart failure with preserved ejection fraction (HFpEF) as defined by the Heart Failure Association (HFA) of the European Society of Cardiology (ESC). METHODS AND RESULTS: We used pooled data from two dedicated HFpEF studies with invasive exercise haemodynamic protocols, the REDUCE LAP-HF (Reduce Elevated Left Atrial Pressure in Patients with Heart Failure) trial and the REDUCE LAP-HF I trial, and categorized patients according to advanced heart failure (AdHF) criteria. The well-characterized HFpEF patients were considered advanced if they had persistent New York Heart Association classification of III-IV and heart failure (HF) hospitalization < 12 months and a 6 min walk test distance < 300 m. Twenty-four (22%) out of 108 patients met the AdHF criteria. On evaluation, clinical characteristics and resting haemodynamics were not different in the two groups. Patients with AdHF had lower work capacity compared with non-advanced patients (35 ± 16 vs. 45 ± 18 W, P = 0.021). Workload-corrected pulmonary capillary wedge pressure normalized to body weight (PCWL) was higher in AdHF patients compared with non-advanced (112 ± 55 vs. 86 ± 49 mmHg/W/kg, P = 0.04). Further, AdHF patients had a smaller increase in cardiac index during exercise (1.1 ± 0.7 vs. 1.6 ± 0.9 L/min/m2 , P = 0.028). CONCLUSIONS: A significantly higher PCWL and lower cardiac index reserve during exercise were observed in AdHF patients compared with non-advanced. These differences were not apparent at rest. Therapies targeting the haemodynamic compromise associated with advanced HFpEF are needed.

Relationship of variable region genes expressed by a human B cell lymphoma secreting pathologic anti-Pr2 erythrocyte autoantibodies.

To study the biology of cold agglutinin disease we previously established EBV-transformed B cell clones isolated from a patient with splenic lymphoma of an early plasmacytic cell type and immune hemolysis due to an anti-Pr2 cold agglutinin. These clones had an aberrant chromosomal marker identical to the patient's B cell lymphoma and each secreted IgMk anti-Pr2 similar to the pathologic autoantibody in the serum of the patient. In this study, we have further investigated the Pr2-specific autoimmune response through nucleotide sequencing of VH and VL region genes. We have shown that the seven clones share the same VDJ/VJ gene segments and junctional elements confirming their clonal origin. The VH sequences were 88% homologous to a VHI germline gene while the VL sequences were 97% homologous to a VkIII germline gene. Only 4 somatic mutations (3 silent and 1 conservative) were found in greater than 5,000 bp sequenced, suggesting that a low mutation rate existed. Based on a tumor mass of 10(12) cells and a minimum of 40 divisions, we estimated the somatic mutation rate to be 4.45 x 10(-5) m/bp/d. This somatic mutation rate is similar to those estimated for acute lymphocytic leukemia (pre-B cell) and chronic lymphocytic leukemia (intermediate B cell), but significantly lower than the mutation frequency in follicular lymphomas (activated B cell). We propose that the difference in somatic mutation frequency of a B cell tumor may be related to the stage of B cell differentiation. In addition, the low mutation frequency observed in the Pr2-specific B cell tumor may also reflect, in part, selection by autoantigen to conserve sIg structure and specificity.

The genetic control of gamma-globulin heavy chains. Studies of the major heavy chain subgroup utilizing multiple genetic markers.

The genetic control of gammaG1-heavy chains was investigated by taking advantage of two recently described genetic antigens, Gm(z) and Gm(y), both produced by heteroimmunization of rabbits with myeloma proteins. These were studied in conjunction with known genetic markers, Gm(a) and Gm(f). The results indicated that among Caucasians there are two major allelic genes, Gm(za) and Gm(fy), coding for distinct varieties of gammaG1-heavy chains. Each of these contains a pair of genetic antigens which are located on different fragments of the chain and can be separated by enzymatic splitting with papain. The different areas of the heavy chains appear to be under the control of the same gene. In Mongoloid populations a grouping of three genetic antigens, Gm(f), (y), and (a), was found on isolated myeloma proteins and normal gamma-globulins indicating the presence of a Gm(fya) gene. The possible genetic events leading to the contrasting Caucasian and Mongoloid genes are discussed. In the gamma-globulin system the occurrence of multiple genetic antigens in different positions of the same heavy chains is the general rule. A better understanding of the relationships between the genes for the gammaG1-subgroup to those for the gammaG2- and gammaG3-subgroup has been obtained through the use of the multiple genetic markers. Strong evidence was obtained for intergenic crossover mechanisms to explain racial differences in the relationships of these genes as well as certain unusual gene complexes found through family studies. Further evidence was obtained for mapping the closely linked genes for the three subgroups in a specific order.

A glycoprotein associated with the membrane fraction of human B but not T lymphocytes.

A method is described which employs differential centrifugation and sucrose density gradient centrifugation to isolate a membrane fraction from human lymphocytes. Membrane preparations from long-term human cultured B- and T-lymphoid lines, peripheral blood lymphocytes, tonsillar lymphocytes, and thymocytes were analyzed on 0.5% sodium dodecyl sulfate-7.5% polyacrylamide gels stained for protein and carbohydrate. The most important finding was a major glycoprotein of approximately 30,000 daltons associated with the membrane preparations from B lymphocytes. T-lymphocyte preparations did not contain readily detectable amounts of this membrane-associated component. The T-cell lymphoid line MOLT-4 was unique in that it had a narrow protein band at approximately 30,000 daltons which did not contain carbohydrate.

The relationship between 2 -microglobulin and immunoglobulin in cultured human lymphoid cell lines.

beta(2)-microglobulin was detected on the cell surface and in the medium of human lymphoid cells established in long-term culture. The secretion of beta(2)-microglobulin was relatively uniform when different cell lines were compared, whereas IgG production varied widely. kappa- and micro-membrane antigens were modulated by specific antibody; beta(2)-microglobulin was not modulated. Anti-kappa and anti-micro antisera had no effect on the expression of membrane beta(2)-microglobulin, nor had anti-beta(2)-microglobulin antiserum any effect on the expression of kappa- and micro-membrane antigens.

Studies of the Vi (gamma-2c) subgroup of gamma-globulin. A relationship between concentration and genetic type among normal individuals.

Further delineation of the antigens characteristic of the Vi or gamma(2c) subgroup of gamma-globulin was carried out utilizing a number of rabbit and primate antisera. Two genetic antigens characteristic of this subgroup, Gm(b) and Gm(g), were also detected by precipitation techniques with certain of the antisera. These were clearly differentiated from antigens common to all proteins of this subgroup. The concentration, of Vi protein in normal and pathological sera from several population groups was measured quantitatively utilizing a variety of immunological procedures. All sera studied showed measurable levels. The mean value for Caucasian sera was 1.06 mg/ml, representing approximately 8% of gammaG-globulin. This agreed closely with a figure of 8.4% for the incidence of myeloma proteins of the Vi subgroup among all gammaG-myeloma proteins in Caucasians. A relationship was found between the Vi subgroup concentration and the specific genetic type of a given individual. Measurements of the Gm(b) genetic determinants, which are found solely in Vi-type proteins, brought forward this relationship. Gm(b+) individuals showed higher concentrations of Vi-type gamma-globulin than those who were Gm(b-), and this difference was statistically significant for both the homozygous and heterozygous states. It appeared that the structural genes for Gm(b+) polypeptide chains showed a greater synthetic capacity than those for Gm(b-) types. The possible significance of such effects in governing the relative composition of the antibody population in a given individual is discussed.

B lymphocytes may escape tolerance by revising their antigen receptors.

To explore mechanisms that prevent autoreactivity in nonautoimmune mice, endogenous immunoglobulin (Ig) light (L) chains that associate with a transgenic anti-DNA heavy chain were analyzed. The antibodies from splenic B cell hybridomas of such mice did not bind double-stranded DNA (dsDNA) and their L chain sequences showed a biased use of V kappa and J kappa gene segments. The 44 L chains in this survey were coded for by just 18 germline genes. Six of the genes, each belonging to a different V kappa group, were used more than once and accounted for three fourths of all sequences. Based on the distribution of V kappa genes, the L chain repertoire in this line of transgenic mice was estimated at 37 V kappa genes. The most frequently observed gene, a member of the V kappa 12/13 group, was identified in 16 hybrids. In addition, the majority of V kappa genes used J kappa 5. We interpret the skewed representation of V kappa and J kappa gene segments to result from negative selection. Based on the data, we suggest that V kappa rearrangements giving rise to anti-dsDNA reactivity are removed from the repertoire by a corrective mechanism capable of editing self-reactive Ig.

Somatic mutation and light chain rearrangement generate autoimmunity in anti-single-stranded DNA transgenic MRL/lpr mice.

Antibodies to single-stranded (ss)DNA are expressed in patients with systemic lupus erythematosus and in lupus-prone mouse models such as the MRL/Mp-lpr/lpr (MRL/lpr) strain. In nonautoimmune mice, B cells bearing immunoglobulin site-directed transgenes (sd-tgs) that code for anti-ssDNA are functionally silenced. In MRL/lpr autoimmune mice, the same sd-tgs are expressed in peripheral B cells and these autoantibodies gain the ability to bind other autoantigens such as double-stranded DNA and cell nuclei. These new specificities arise by somatic mutation of the anti-ssDNA sd-tgs and by secondary light chain rearrangement. Thus, B cells that in normal mice are anergic can be activated in MRL/lpr mice, which can lead to the generation of pathologic autoantibodies. In this paper, we provide the first direct evidence for peripheral rearrangement in vivo.

Characterization of cystic fibrosis factor and its interaction with human immunoglobulin.

Cystic fibrosis factor activity (CFFA), assayed as the ability to stop oyster ciliary movement, was present in serum-free medium from actively growing cystic fibrosis skin fibroblast cultures. CFFA was associated with a low molecular weight, negatively charged molecule that contained no uronic acid and was heat and pH labile. When CFFA-positive media were mixed with human IgG1, the CFFA was chromatographically displaced and emerged with the IgG1 fraction on column chromatography. Experiments in which various immunoglobulins were added to CFFA-positive culture media and then incubated with specific anti-immunoglobulins suggested that CFFA binding was class specific for human IgG, subclass specific for IgG1 and IgG2, and occurred with intact unaggregated heavy chains but not with kappa- and lambda-light chains, or Fab, Fc, and F(ab')(2) fragments. The serum protein beta(2)-microglobulin, which has structural homology to IgG, also bound CFFA.

Esophageal motion during radiotherapy: quantification and margin implications.

The purpose was to evaluate interfraction and intrafraction esophageal motion in the right-left (RL) and anterior-posterior (AP) directions using computed tomography (CT) in esophageal cancer patients. Eight patients underwent CT simulation and CT-on-rails imaging before and after radiotherapy. Interfraction displacement was defined as differences between pretreatment and simulation images. Intrafraction displacement was defined as differences between pretreatment and posttreatment images. Images were fused using bone registries, adjusted to the carina. The mean, average of the absolute, and range of esophageal motion were calculated in the RL and AP directions, above and below the carina. Thirty-one CT image sets were obtained. The incidence of esophageal interfraction motion > or =5 mm was 24% and > or =10 mm was 3%; intrafraction motion > or =5 mm was 13% and > or =10 mm was 4%. The average RL motion was 1.8 +/- 5.1 mm, favoring leftward movement, and the average AP motion was 0.6 +/- 4.8 mm, favoring posterior movement. Average absolute motion was 4.2 mm or less in the RL and AP directions. Motion was greatest in the RL direction above the carina. Coverage of 95% of esophageal mobility requires 12 mm left, 8 mm right, 10 mm posterior, and 9 mm anterior margins. In all directions, the average of the absolute interfraction and intrafraction displacement was 4.2 mm or less. These results support a 12 mm left, 8 mm right, 10 mm posterior, and 9 mm anterior margin for internal target volume (ITV) and can guide margins for future intensity modulated radiation therapy (IMRT) trials to account for organ motion and set up error in three-dimensional planning.

Unobstructive total anomalous pulmonary venous return: impact of early elective repair on the need for prolonged mechanical ventilatory support.

Optimal timing for elective repair of total anomalous pulmonary venous return (TAPVR) in the case of an unobstructed anomalous pathway is unclear. All infants with a diagnosis of TAPVR as an isolated lesion who underwent surgical repair at Children's Hospital of Wisconsin from 1991 to 2007 were reviewed to assess location of drainage, presence of obstruction, age at presentation, age at surgery, death, need for extracorporeal membrane oxygenation (ECMO), length of hospital stay, length of mechanical ventilation (MV), and late pulmonary venous obstruction. A total of 65 patients were identified: 38 (59%) with supracardiac drainage, 10 (15%) with cardiac drainage, 11 (17%) with infracardiac drainage, and 6 (9%) with mixed drainage. For 39 (60%) of the 65 patients, obstruction was identified preoperatively. Three early and five late deaths occurred after surgery (12%), all involving patients with preoperative obstruction. Most of the late deaths (80%) involved patients who experienced recurrent obstruction. Of the 65 patients, 26 (40%) had no obstruction preoperatively, and none died, required ECMO support, or experienced late obstruction. For the 26 patients without obstruction, the timing of surgery was elective at the discretion of the supervising cardiologist. Among these 26 patients, 15 had surgery less than 10 days after presentation (median age, 18 days), and 53% of these 15 patients (8/15) had MV less than 5 days. In contrast, all 11 patients who had elective surgery more than 10 days after presentation (median age, 56 days) required MV for more than 5 days (p = 0.007). Isolated TAPVR appears to be at the highest risk for death and late postoperative obstruction when obstruction is present preoperatively. Patients with unobstructive TAPVR do very well, but potential morbidity related to prolonged MV appears to be significantly reduced by early elective surgery.

Life history of mouse sperm protein. Intratesticular stages.

A basic protein fraction, migrating as a single band in acetic acid-urea gel, distinct from histones, was isolated from mouse sperm collected from vasa deferentia and caudae epididymides and was used to immunize female rabbits. The presence of antibodies to the mouse sperm protein (MSP) in the rabbit antisera was demonstrated by a cytoimmunofluorescence procedure using the cells of origin of the antigenic protein, the mature mouse sperm. The specificity of the antisera was verified by fluid and gel precipitation tests and by crossed immunoelectrophoresis. The latter procedure demonstrated the presence of two antigen-antibody systems, consonant with earlier reports that the basic chromosomal protein of mouse sperm is heterogeneous. MSP antigen in situ was recognized by the specific antibodies of the rabbit antisera only after the smear of mature sperm was treated with either of two reducing agents: 2-mercaptoethanol or dithiothreitol. However, when the immunofluorescence procedure was applied to untreated smears of mouse testicular cells, spermatids of all stages from 1 to 14-15 were positive, while spermatocytes, stage 16 spermatids and spermatozoa were negative. After treatment of testes smears with reducing agent, only spermatocytes remained negative. Those observations indicate the following: (a) MSP is immunogenic in a heterologous species; (b) its antigenic sites are detectable in spermatozoa and spermatids of all stages, but not in primary spermatocytes; (c) those antigenic sites become masked at about stage 15 of spermiogenesis and may be unmasked by treatment with a reducing agent. The interpretation is made, therefore, that one or more components of MSP are assembled at the beginning of spermiogenesis and undergo an alteration in the final intratesticular stage of spermatid maturation. That alteration may be presumed to be the formation of disulfide linkages between the cysteine residues.

Genetically determined antigen of the Ne subgroup of gamma-globulin: detection by precipitin analysis.

A genetic antigen, Gm(n), has been described for the Ne subgroup of gamma-globulin previously devoid of Gm factors. It was detected by precipitin tests with a primate antiserum to Ne-type heavy chains. A relation to the Gm(b) antigens of the Vi subgroup and the Gm(f) and Gm(y) antigens of the We subgroup was apparent. The availablity of genetic antigens for the heavy chains of three subgroups of gamma-globulin with varying relationships in different populations offers an approach to the mapping of the genes concerned.

Abnormal immune responses of Bloom's syndrome lymphocytes in vitro.

Bloom's syndrome is a rare autosmal recessive disorder, first characterized by growth retardation and asum-sensitive facial telangiectasia and more recently demonstarted to have increased chromosome instability, a predisposition to malignancy, and increased susecptibitily to infection. The present report ocncern the immune function of Bloom's syndrom lymphoctes in vitro. Four affected homozgotes and five heterozygotes were studied. An abnormal serum concentartion of at least one class of immunoglobin was present in three out of four homozgotes. Affected homozgotes were shown capable of both a humoral and cellular response after antigenic challenge, the responses in general being weak but detectable. Blood lymphocytes from Bloom's syndrome individuals were cultured in impaired proliferavite response and synthesized less immunoglobulin at the end of 5 days than did normal controls. In contrast, they had a normal proliferative response to phytohemagglutinin except at highest concentrations of the mitogen. In the mixed lymphocte culture, Bloom's syndrome lymphocytes proved to be poor responder cells but normal stimulator cells. Lmyphoctes from the heterozgotes produced normal responses in these three systems. Distrubed immunity appears to be on of several major consequences of homozygosity for the Bloom's syndrome gene. Although the explanation for this pleiotropism is at present obscure, the idea was advanced that the aberrant immune function is, along with the major clincial feature-small body size, amanifestation of defect in cellular proliferation.

Abnormal cardiac function in the streptozotocin-diabetic rat. Changes in active and passive properties of the left ventricle.

To provide an integrated assessment of changes in systolic and diastolic function in diabetic rats, we measured conscious hemodynamics and performed ex vivo analysis of left ventricular passive-elastic properties. Rats given streptozotocin (STZ) 65 mg/kg i.v. (n = 14) were compared with untreated age-matched controls (n = 15) and rats treated with insulin after administration of STZ (n = 11). After 7 d, diabetic rats exhibited decreases in heart rate and peak developed left ventricular (LV) pressure during aortic occlusion. After 26 d of diabetes there were significant decreases in resting LV systolic pressure, developed pressure, and maximal +dP/dt, whereas LV end-diastolic pressure increased and the time constant of LV relaxation was prolonged. The passive LV pressure-volume relationship was progressively shifted away from the pressure axis, and the overall chamber stiffness constant was decreased. However, "operating chamber stiffness" calculated at end-diastolic pressure was increased at 7 d, and unchanged at 26 d. LV cavity/wall volume and end-diastolic volume were increased after 26 d of diabetes. Myocardial stiffness was unchanged at both time intervals. All of the above abnormalities were reversed by the administration of insulin. We conclude that the hemodynamic and passive-elastic changes that occur in diabetic rats represent an early dilated cardiomyopathy which is reversible with insulin.

Evidence for tissue-specific activation of renal angiotensinogen mRNA expression in chronic stable experimental heart failure.

The intrarenal renin-angiotensin system (RAS) may contribute to the pathophysiology of heart failure by the generation of angiotensin II at local sites within the kidneys. Angiotensin II may directly influence renal hemodynamics, glomerular contractility, and tubular sodium reabsorption, thereby promoting sodium and fluid retention in this syndrome. In the present study, we examined components of the circulating RAS as well as the intrarenal expressions of renin and angiotensinogen mRNA in rats with stable compensated heart failure (HF) 12 wk after experimental myocardial infarction. Renal angiotensinogen mRNA level in vehicle-treated HF rats increased 47%, as compared with sham control rats (P = 0.001). The increase in angiotensinogen mRNA levels was more pronounced in animals with medium (46%, P < 0.05) and large (66%, P < 0.05) infarcts than in those with small infarcts (31%, P = NS). There were no differences in liver angiotensinogen mRNA, circulating angiotensinogen, angiotensin II, plasma renin concentration (PRC), kidney renin content (KRC), and renal renin mRNA level between sham and HFv. In addition, in a separate group of rats with heart failure, we demonstrated that renal angiotensin II concentration increased twofold (P < 0.05) as compared with that of age-matched sham operated controls. A parallel group of heart failure rats (HFe, n = 11) was treated with enalapril (25 mg/kg per d) in drinking water for 6 wk before these measurements. Blood pressure decreased significantly during treatment (91 vs. 103 mm Hg, P < 0.05). Enalapril treatment in HF rats increased renin mRNA level (2.5-fold, P < 0.005), KRC (5.6-fold, P = 0.005), and PRC (15.5-fold, P < 0.005). The increase in renal angiotensinogen mRNA level observed in HFv rats was markedly attenuated in enalapril treated HF rats (P < 0.001), suggesting a positive feedback of angiotensin II on renal angiotensinogen synthesis. These findings demonstrate an activation of intrarenal RAS, but no changes in the circulating counterpart in this model of experimental heart failure, and they support the concept that the intrinsic renal RAS may contribute to the pathophysiology in this syndrome.

Modulation of gene expression in subjects at risk for colorectal cancer by the chemopreventive dithiolethione oltipraz.

Prolonged exposure to mutagenic substances is strongly associated with an individual's risk of developing colorectal cancer. Clinical investigation of oltipraz as a chemopreventive agent is supported by its induction of the expression of detoxication enzymes in various tissues, and its protective activity against the formation of chemically induced colorectal tumors in animals. The goals of the present study were: to determine if oltipraz could induce detoxicating gene expression in human tissues; to identify effective non-toxic doses for more extensive clinical testing; and to establish a relationship between effects in the colon mucosa and those in a more readily available tissue, the peripheral mononuclear cell. 24 evaluable patients at high risk for colorectal cancer were treated in a dose-finding study with oltipraz 125, 250, 500, or 1,000 mg/m2 as a single oral dose. Biochemical analysis of sequential blood samples and colon mucosal biopsies revealed increases in glutathione transferase activity at the lower dose levels. These effects were not observed at the higher doses. More pronounced changes were observed in detoxicating enzyme gene expression in both tissues at all doses. Peripheral mononuclear cell and colon mRNA content for gamma-glutamylcysteine synthetase (gamma-GCS) and DT-diaphorase increased after dosing to reach a peak on day 2-4 after treatment, and declined to baseline in the subsequent 7-10 d. The extent of induction of gene expression in colon mucosa reached a peak of 5.75-fold for gamma-GCS, and a peak of 4.14-fold for DT-diaphorase at 250 mg/m2 ; higher doses were not more effective. Levels of gamma-GCS and DT-diaphorase correlated closely (P < or = 0.001) between peripheral mononuclear cells and colon mucosa both at baseline and at peak. These findings demonstrate that the administration of minimally toxic agents at low doses may modulate the expression of detoxicating genes in the tissues of individuals at high risk for cancer. Furthermore, peripheral mononuclear cells may be used as a noninvasive surrogate endpoint biomarker for the transcriptional response of normal colon mucosa to drug administration.