Effects of Renal Denervation vs Sham in Resistant Hypertension After Medication Escalation: Prespecified Analysis at 6 Months of the RADIANCE-HTN TRIO Randomized Clinical Trial

Importance

Although early trials of endovascular renal denervation (RDN) for patients with resistant hypertension (RHTN) reported inconsistent results, ultrasound RDN (uRDN) was found to decrease blood pressure (BP) vs sham at 2 months in patients with RHTN taking stable background medications in the Study of the ReCor Medical Paradise System in Clinical Hypertension (RADIANCE-HTN TRIO) trial.

Objectives

To report the prespecified analysis of the persistence of the BP effects and safety of uRDN vs sham at 6 months in conjunction with escalating antihypertensive medications.

Design, Setting, and Participants

This randomized, sham-controlled, clinical trial with outcome assessors and patients blinded to treatment assignment, enrolled patients from March 11, 2016, to March 13, 2020. This was an international, multicenter study conducted in the US and Europe. Participants with daytime ambulatory BP of 135/85 mm Hg or higher after 4 weeks of single-pill triple-combination treatment (angiotensin-receptor blocker, calcium channel blocker, and thiazide diuretic) with estimated glomerular filtration rate (eGFR) of 40 mL/min/1.73 m2 or greater were randomly assigned to uRDN or sham with medications unchanged through 2 months. From 2 to 5 months, if monthly home BP was 135/85 mm Hg or higher, standardized stepped-care antihypertensive treatment starting with aldosterone antagonists was initiated under blinding to treatment assignment.

Interventions

uRDN vs sham procedure in conjunction with added medications to target BP control.

Main Outcomes and Measures

Six-month change in medications, change in daytime ambulatory systolic BP, change in home systolic BP adjusted for baseline BP and medications, and safety.

Results

A total of 65 of 69 participants in the uRDN group and 64 of 67 participants in the sham group (mean [SD] age, 52.4 [8.3] years; 104 male [80.6%]) with a mean (SD) eGFR of 81.5 (22.8) mL/min/1.73 m2 had 6-month daytime ambulatory BP measurements. Fewer medications were added in the uRDN group (mean [SD], 0.7 [1.0] medications) vs sham (mean [SD], 1.1 [1.1] medications; P = .045) and fewer patients in the uRDN group received aldosterone antagonists at 6 months (26 of 65 [40.0%] vs 39 of 64 [60.9%]; P = .02). Despite less intensive standardized stepped-care antihypertensive treatment, mean (SD) daytime ambulatory BP at 6 months was 138.3 (15.1) mm Hg with uRDN vs 139.0 (14.3) mm Hg with sham (additional decreases of -2.4 [16.6] vs -7.0 [16.7] mm Hg from month 2, respectively), whereas home SBP was lowered to a greater extent with uRDN by 4.3 mm Hg (95% CI, 0.5-8.1 mm Hg; P = .03) in a mixed model adjusting for baseline and number of medications. Adverse events were infrequent and similar between groups.

Conclusions and Relevance

In this study, in patients with RHTN initially randomly assigned to uRDN or a sham procedure and who had persistent elevation of BP at 2 months after the procedure, standardized stepped-care antihypertensive treatment escalation resulted in similar BP reduction in both groups at 6 months, with fewer additional medications required in the uRDN group.

Trial Registration

ClinicalTrials.gov Identifier: NCT02649426.

Six-Month Results of Treatment-Blinded Medication Titration for Hypertension Control After Randomization to Endovascular Ultrasound Renal Denervation or a Sham Procedure in the RADIANCE-HTN SOLO Trial

BACKGROUND

The multicenter, international, randomized, blinded, sham-controlled RADIANCE-HTN SOLO trial (A Study of the ReCor Medical Paradise System in Clinical Hypertension) demonstrated a 6.3 mm Hg greater reduction in daytime ambulatory systolic blood pressure (BP) at 2 months by endovascular ultrasound renal denervation (RDN) compared with a sham procedure among patients not treated with antihypertensive medications. We report 6-month results after the addition of a recommended standardized stepped-care antihypertensive treatment to the randomized endovascular procedure under continued blinding to initial treatment.

METHODS

Patients with a daytime ambulatory BP ≥135/85 mm Hg and <170/105 mm Hg after a 4-week discontinuation of up to 2 antihypertensive medications, and a suitable renal artery anatomy, were randomized to RDN (n=74) or sham (n=72). Patients were to remain off antihypertensive medications throughout the first 2 months of follow-up unless safety BP criteria were exceeded. Between 2 and 5 months, if monthly measured home BP was ≥135/85 mm Hg, a standardized stepped-care antihypertensive treatment was recommended consisting of the sequential addition of amlodipine (5 mg/d), a standard dose of an angiotensin-converting enzyme inhibitor/angiotensin receptor blocker, and hydrochlorothiazide (12.5 mg/d), followed by the sequential uptitration of hydrochlorothiazide (25 mg/d) and amlodipine (10 mg/d). Outcomes included the 6-month (1) change in daytime ambulatory systolic BP adjusted for medications and baseline systolic BP, (2) medication burden, and (3) safety.

RESULTS

A total of 69/74 RDN patients and 71/72 sham patients completed the 6-month ambulatory BP measurement. At 6 months, 65.2% of patients in the RDN group were treated with the standardized stepped-care antihypertensive treatment versus 84.5% in the sham group (P=0.008), and the average number of antihypertensive medications and defined daily dose were less in the RDN group than in the sham group (0.9±0.9 versus 1.3±0.9, P=0.010 and 1.4±1.5 versus 2.0±1.8, P=0.018; respectively). Despite less intensive standardized stepped-care antihypertensive treatment, RDN reduced daytime ambulatory systolic BP to a greater extent than sham (-18.1±12.2 versus -15.6±13.2 mm Hg, respectively; difference adjusted for baseline BP and number of medications: -4.3 mm Hg, 95% confidence interval, -7.9 to -0.6, P=0.024). There were no major adverse events in either group through 6 months.

CONCLUSIONS

The BP-lowering effect of endovascular ultrasound RDN was maintained at 6 months with less prescribed antihypertensive medications compared with a sham control.

CLINICAL TRIAL REGISTRATION

URL: https://www.

CLINICALTRIALS

gov. Unique identifier: NCT02649426.

Glass fibers covered with sol-gel glass as a new support for affinity chromatography columns: a review

The search for mechanical supports for biochemically active compounds serving as immunochemical sensors has been the goal of many studies. A new compound in the form of gel fiberglass (GFG) membranes was recently developed as an example of such supports. In this review, these membranes were analyzed with respect to their use for cancer detection. The membranes are prepared from glass fibers covered with oxysilane to provide a sol-gel glass matrix. Derivatization of the support eliminates nonspecific adsorption. A thin layer of protein trapped in the gel glass during its preparation is deposited on the surface of a lattice of glass fibers. The major innovation of the membrane is its large area. External agents percolating through such a membrane contact a maximal number of molecules of the compounds trapped in the sol-gel glass. As a result, this membrane is highly effective. Each GFG column is built from a series of 20 to 30 membranes. The preparation of such columns is relatively simple, requiring only several hours. The capacity of GFG columns is high: the total amount of tumor-associated antigens (TAA) isolated by these columns from the blood of colon cancer patients reached 50% of the total protein and amounted to up to 9-12 mg/ml of serum. The main components of the isolated TAA were the soluble p66 and p51 proteins. A determination of their concentration by HPLC can be used for early cancer detection. Thus, the described method allows the easy and highly effective isolation of TAA and can be used for different goals, including cancer diagnosis. GFG supports have great potential for the isolation of various macromolecules utilizing specific ligands.

Management of sexual dysfunction in patients with cardiovascular disease: recommendations of the Princeton Consensus Panel

Sexual dysfunction is highly prevalent in both sexes and adversely affects patients' quality of life and well being. Given the frequent association between sexual dysfunction and cardiovascular disease, in addition to the potential cardiac risk of sexual activity itself, a consensus panel was convened to develop recommendations for clinical management of sexual dysfunction in patients with cardiovascular disease. Based upon a review of the research and presentations by invited experts, a classification system was developed for stratification of patients into high, low, and intermediate categories of cardiac risk. The large majority of patients are in the low-risk category, which includes patients with (1) controlled hypertension; (2) mild, stable angina; (3) successful coronary revascularization; (4) a history of uncomplicated myocardial infarction (MI); (5) mild valvular disease; and (6) no symptoms and <3 cardiovascular risk factors. These patients can be safely encouraged to initiate or resume sexual activity or to receive treatment for sexual dysfunction. An important exception is the use of sildenafil in patients taking nitrates in any form. Patients in the intermediate-risk category include those with (1) moderate angina; (2) a recent MI (<6 weeks); (3) left ventricular dysfunction and/or class II congestive heart failure; (4) nonsustained low-risk arrhythmias; and (5) >/=3 risk factors for coronary artery disease. These patients should receive further cardiologic evaluation before restratification into the low- or high-risk category. Finally, patients in the high-risk category include those with (1) unstable or refractory angina; (2) uncontrolled hypertension; (3) congestive heart failure (class III or IV); (4) very recent MI (<2 weeks); (5) high-risk arrhythmias; (6) obstructive cardiomyopathies; and (7) moderate-to-severe valvular disease. These patients should be stabilized by specific treatment for their cardiac condition before resuming sexual activity or being treated for sexual dysfunction. A simple algorithm is provided for guiding physicians in the management of sexual dysfunction in patients with varying degrees of cardiac risk.

Management of sexual dysfunction in patients with cardiovascular disease: recommendations of The Princeton Consensus Panel

Sexual dysfunction is highly prevalent in both sexes and adversely affects patients' quality of life and well being. Given the frequent association between sexual dysfunction and cardiovascular disease, in addition to the potential cardiac risk of sexual activity itself, a consensus panel was convened to develop recommendations for clinical management of sexual dysfunction in patients with cardiovascular disease. Based upon a review of the research and presentations by invited experts, a classification system was developed for stratification of patients into high, low, and intermediate categories of cardiac risk. The large majority of patients are in the low-risk category, which includes patients with (1) controlled hypertension; (2) mild, stable angina; (3) successful coronary revascularization; (4) a history of uncomplicated myocardial infarction (MI); (5) mild valvular disease; and (6) no symptoms and <3 cardiovascular risk factors. These patients can be safely encouraged to initiate or resume sexual activity or to receive treatment for sexual dysfunction. An important exception is the use of sildenafil in patients taking nitrates in any form. Patients in the intermediate-risk category include those with (1) moderate angina; (2) a recent MI (<6 weeks); (3) left ventricular dysfunction and/or class II congestive heart failure; (4) nonsustained low-risk arrhythmias; and (5) >/=3 risk factors for coronary artery disease. These patients should receive further cardiologic evaluation before restratification into the low- or high-risk category. Finally, patients in the high-risk category include those with (1) unstable or refractory angina; (2) uncontrolled hypertension; (3) congestive heart failure (class III or IV); (4) very recent MI (<2 weeks); (5) high-risk arrhythmias; (6) obstructive cardiomyopathies; and (7) moderate-to-severe valvular disease. These patients should be stabilized by specific treatment for their cardiac condition before resuming sexual activity or being treated for sexual dysfunction. A simple algorithm is provided for guiding physicians in the management of sexual dysfunction in patients with varying degrees of cardiac risk.

Morphological and morphometric studies of the splenic antitumor immune response, elicited by liposome-covered soluble p53 kDa antigen, in chemically-induced rat colon cancer

We evaluated the splenic morphometric changes in rats treated with carcinogen to study development of anti-cancer immune response. When liposome-covered soluble 53 kDa antigen (s53) was injected into these rats, significant tumor-suppression was seen and the percentage of tumor-free animals rose from 15.4% in non-vaccinated rats to 53.8%. In the spleens of carcinogen treated rats that did not develop tumors, activity of B lymphocytes increased significantly. This was manifested by the expansion of the germinal centers to 50.9% of the follicular area reflecting depletion of B cells, and the decrease of the mantle layer to 48.9% of the follicles. A similar picture was seen with T lymphocytes: the area of the marginal zone decreased to 55.2% of the T zone of the white pulp, and that of the periarterial lymph sheaths (PALS) to 33.6%. In tumor-bearing rats features of the immune decompensation were seen: the germinal centers increased to 96.5% of the follicular area, and the mantle layer and PALS decreased significantly. Vaccination prevented these effects, especially in tumor-bearing rats: the PALS occupies 30.4% of the white pulp and the marginal zone 56.1%, and the mantle layer occupied 58.1% of the follicular zone. Similar changes were found in vaccinated rats without tumors reflecting the compensatory character of the immune reaction in vaccinated rats. In conclusion, we found that treatment with carcinogen followed by vaccination with the s53-liposomes complex stimulated the activity of the splenic B, and to a lesser degree the T systems.

Specificity of polyclonal anti-p53 IgG for isolation of the soluble p53 antigen from human serum

The possibility to use anti-p53 IgG for isolation of the soluble p53 antigen as a serological tumor marker has been shown in our previous studies. In order to prove the specificity of such IgG, we compared the effectiveness of columns with anti-p53 IgG and IgG isolated from non-treated rabbits (regular IgG). The gel fiberglass (GFG) columns for affinity chromatography were prepared separately with both types of IgG. The same serum was percolated simultaneously through both columns and the results of elution were compared. The total concentration of tumor-associated antigens (TAA) eluted from the serum of cancer patients was similar in both TAA mixtures isolated either with anti-p53 IgG or with the regular IgG. Differences are manifest in the content of total proteins and amount of each eluted protein: a mixture eluted with the regular IgG contains several proteins whereas the anti-p53 IgG isolated only two proteins, p64 and p53. The amount of the soluble p53 antigen isolated from the cancer serum was significantly higher when it was isolated with anti-p53 IgG. The method developed in our laboratory was shown to be highly specific both to isolate proteins related to cancer (p53) and non-cancer disorders (p64). Data presented in this report show that such specificity can be achieved only if the anti-p53 IgG is used: the regular IgG obtained from non-treated animals isolate many proteins among which the concentration of specific p53 protein is lost.

The role of the soluble p53 antigen and its autoantibodies as markers for diagnosis of colon cancer: a comparative study

The role of various serological tumor markers, p53 soluble antigen and its autoantibodies, was evaluated for the detection of colon cancer in humans. An HPLC technique was used to measure serum levels of both forms of p53 protein after their partial isolation on gel fiberglass affinity chromatography columns. Tumor-associated proteins (TAP) in the form of either antigens or autoantibodies were about 4% of the total protein isolated from the serum of colon cancer patients. The absolute amount of each of the two types of TAP was also similar: 14.69 2.88 and 18.29 3.85 mg ml-1, respectively. The amount of p53 autoantibodies was higher than those of p53 antigen, but the difference was not significant: 9.35 3.48 and 6. 19 3.87 mg/ml, respectively (p>0.05). A good correlation was found between the total amount of tumor-associated antigens (TAA) and the amount of p53 antigen (r=0.69), total amount of IgG and the amount of p53 autoantibodies (r=0.46), and between both forms of p53 protein (r=0.46). A high coefficient of regression was found between the total amount of TAA and the amount of p53 antigen (b=2.4). Relationships between Duke's stage in colon cancer and the serum levels of p53 protein were weak: 0.33 and -0.32 for p53 antigen and its autoantibodies, respectively. Serum determination of p53 autoantibodies has no advantage over the determination of p53 antigen. Both forms of p53 protein can be isolated with extremely high accuracy for the pathological diagnosis of cancer (87-93%). Specificity of the method was proved using of commercial p53 PAb OD1: the GFG columns with this antibody were able to isolate the same proteins which were isolated by GFG columns with anti-p53 IgG. Moreover, the isolation of p53 protein was performed with higher effectiveness using the GFG columns with entrapped anti-p53 IgG than those columns with commercial DO1 PAb.

Expression of p53 protein in rat colon cancer cell lines transfected with Rous sarcoma virus-33

Expression of the cytoplasmic soluble form of p53 protein in the different rat colon cancer cell lines transfected and non-transfected with Rous sarcoma virus-33 was studied. Concentrations of the p53 protein were detected by commonly used immunochemical methods after its isolation by affinity chromatography columns with the gel fiberglass membranes. The main component of tumor-associated antigens (TAA) eluted from virus-transfected cells was the 53 kDa protein in its cytoplasmic soluble fraction. The non-virogenic colon cancer cells contain a few proteins and concentration of 53 kDa protein was low. Western immunoblotting revealed that the 53 kDa protein isolated from the cell lyzates studied was distinctly recognized by the p53 MAb. ELISA showed that its concentration was markedly higher in the lyzate obtained from the highly virogenic and tumorigenic R9 cell line compared with the non-virogenic cell line RT1. We concluded that the expression of the p53 protein is related to the viral transfection of cancerous cells. The possible role of this phenomenon in the etiology of cancer is discussed.

Gel fiberglass as a new matrix of affinity chromatography columns for isolation of colon cancer-associated antigens

Gel fiberglass (GFG), a new affinity biosensor, was used to isolate human p53 antigen with rabbit anti-rat p53 IgG. The biosensor was prepared as a membrane from glass fibers covered with oxysilanes. A thin layer of protein, trapped in gel glass during its preparation, is deposited on the surface of a lattice of glass fibers. In such conditions, a maximum number of protein molecules may contact external agents percolated through a membrane. The membranes demonstrate high stability and can be stored in dry conditions or several months at room temperature. Columns for affinity chromatography were prepared from the GFG membranes and were used to isolate various proteins, including the tumor-associated antigens (TAA). The capacity of such columns was calculated as the amount mg of protein isolated from 1 ml of TAA-containing serum. In colon cancer patients, up to 5-6 mg TAA were extracted from 1 mi of sera. Two main components of cytoplasmic TAA isolated in our experiments were p64 and p53 proteins. Their concentration was determined by HPLC. The p53 protein has been isolated from the serum of cancer patients in the highest concentration yet reported, up to 3-4 mg/ml. In our previous studies, isolation of p53 protein was based on its affinity reaction with anti-p53 IgG generated against antigens of the same species. Herein, we report for the first time the capability to isolate human p53 antigen using GFG columns with entrapped anti-rat p53 IgG. Blood levels of p53 antigen isolated were very similar in both experiments. This has both theoretical and practical significance, demonstrating that the GFG membranes have great potential for isolating macromolecules utilizing various ligands. The finding facilitates an easy and highly effective method to isolate antigens from different organs, both animal and human, which can be used for important goals including diagnosis, therapy and generation of specific antibodies.

HPLC determination of serum levels of soluble p53 antigen as a new method for colon cancer detection, and its clinical implication

Previously, we have described a new modification of affinity chromatography columns for isolation of the cytoplasmic, soluble form of tumor-associated antigens (TAA) from the serum of colon cancer patients (Oncol Rep 2: 679-683, 1995). In this communication, we have shown that the main proteins of these TAA were p64 and p53. The correlation coefficient between each of these proteins and the total amount of TAA or total serum protein ranged from 0.55 to 0.93. The serum level of p53 antigen was shown to be related to the tumorigenicity: the correlation and regression coefficients between the serum level of p53 protein and the progress in colon cancer were 0.48 and 0.88, respectively, p<0.001. Therefore, the determination of serum concentration of this protein can serve as a screening tool for cancer detection. The serum level of p53 protein ranges between 0.24 to 0.94 mg/ml in patients with non cancer diseases, and between 1.0 to 2.0 mg/ml in patients with polyposis and in a high risk group, respectively, increases over 2.0 mg/ml in primary colon cancer patients and up to 5.0 mg/ml in cancer patients with metastases. The sensitivity and specificity of our method achieved 92% and 96%, respectively, and accuracy 88%. The presence of p53 protein in the cytoplasm of cells from patients with non cancer diseases may explain why p53 antigen is presented in their sera. Our method can be useful to detect cancer development either as a primary illness or as a recurrent disorder. It is possible to follow up patients with chronic diseases and to detect transformation of these diseases into cancer, or to follow up former cancer patients in order to detect as early as possible incidence of recurrent cancer. It should also be emphasized that our method allows the detection of patients with polyposis or those of high risk groups who exhibit a tendency to develop colon cancer.

IgG generated against benign tumor-associated antigens prevented the effects of 1,2-dimethylhydrazine in rats

We showed the possibility of significant decreasing of the frequency of chemically induced colon cancer in rats by vaccination with polyclonal rabbit IgG generated against purified tumor-associated antigens (TAA). TAA were isolated from benign rat colon tumors by the method developed in our laboratory (Zusman et al 1994) using affinity chromatography columns with gel fiberglass membranes (R. Zusman, 1992) containing anti-tumor IgG. The IgG was isolated from rabbits following their vaccination with TAA. Sprague Dawley rats were vaccinated with anti-TAA IgG (100 micrograms/rat) suspended in Freunds adjuvant by weekly subcutaneous injections for 5 weeks. The induction of colon cancer was caused by weekly injections with 1,2-dimethylhydrazine (DMH) (20 mg/kg) for 7 weeks and was started one week after the end of the vaccination. The results of experiments were evaluated 6 months after the start of cancer induction. IgG protected against the carcinogenic effects of DMH. The number of tumor-bearing rats decreased to 64% as compared with 90% in the control group. In vaccinated rats, the incidence of tumors was almost 3 times less than of control, i.e. 3.6 and 9.3, respectively. The number of malignant tumors was also significantly smaller in vaccinated rats than in controls, being 24% and 58%, respectively. Metastases were found only in controls, 4 of 30 rats. The results of our experiments have shown that anti-TAA IgG not only has anti-tumor effects but also prevents the malignization of benign tumors. As one of the main components of TAA which was isolated from colon cancer rats was soluble p53 antigen (Zusman et al 1994), we suggest that the vaccine which has been generated in our experiments may be regarded as acting mainly against p53 antigen, and its antitumor effects should also be considered as effects of p53 antibodies. The further studies will be performed to clarify this.

Comparative study of the role of serum levels of p53 antigen and its tumor cell concentration in colon cancer detection

The role of serum levels of p53 antigen in detection of colon cancer was studied in different groups of cancer and noncancer patients and was compared with the results of immunohistochemical analyses. The p53 antigen was isolated from the human serum as a cytoplasmic fraction using the recently described new type of columns for affinity chromatography, gel fiberglass columns (Zusman and Zusman, 1995). Its concentration was detected by high performance liquid chromatography. The serum level of the p53 antigen significantly increased in cancer patients (3.6 mg ml(-1)) as compared to its concentration in patients with benign tumors (1.7 mg ml(-1)) or in patients with noncancer disorders (0.49 mg ml(-1)), and this was found to be a result of higher concentration of p53 protein in tumor cells. Coefficient of correlation between cellular concentration of p53 protein and its serum level was 0.44 in noncancer lesions and 0.48 in cancer patients. Serum levels of p53 antigen was shown to be highly active either in patients with noncancer lesions or in patients with cancer (r = 0.46 and 0.51 respectively), whereas the cell determination of p53 protein was effective only among noncancer patients (r = 0.61) but not in cancer patients (r = 0.22). The findings suggests that serum determination of p53 antigen can perhaps reveal this oncoprotein already in the early stages of cancer or even predict the putative development of cancer. The possibility to use the serum-levels of p53 antigen in the follow up patients with chronic diseases and to detect transformation of these diseases into cancer, or monitoring former cancer patients in order to detect as early as possible the incidence of recurrent cancer is discussed.

Isolation of p53 protein from the serum of colon-cancer and noncancer patients

A new method for the isolation of p53 protein from the sera of cancer and non-cancer patients has been developed. The method is based on the utilization of a new modification of a support for affinity chromatography in the form of gel fiberglass (GFG) (R. Zusman, patent applications, Israel, 1992; USA 1993). The sera were percolated through GFG columns with entrapped rabbit IgG generated against the colon cancer antigens. Tumor-associated antigens were eluted from sera of cancer patients in large amounts, up to 2.4 mg/ml serum/column. Concentrations of these antigens in different sera and their affinity to anti-tumoral antibodies were detected by ELISA. Western immunoblotting with commercial monoclonal antibodies and SDS-PAGE identified the isolated antigens as the p53 protein. This protein has been isolated in the highest concentration yet reported from the serum of cancer patients, up to 1 mg/ml. The same protein has been found in the serum of healthy people and non-cancer patients but in significantly lower concentrations. Isolation of p53 protein from sera of noncancer patients confirms the opinion of some investigators that this protein should be considered not only as an oncogene but also as a protein correlated with different changes in the cell cycle.

Purification of sheep immunoglobin G using protein A trapped in sol-gel glass

An effective method for purifying immunoglobulins has been developed utilizing a sol-gel glass support system. Sol-gel glass is an effective support for chemically active ligands entrapped in this medium at room temperature. There are two problems associated with the utilization of such sol-gel glasses for entrapping macromolecules. One is the phenomenon of nonspecific absorption of proteins onto the glass. The second is that only a portion of the entrapped molecules may retain their biological activity. In the present study a sol-gel glass was treated with gamma-aminopropyltriethoxysilane to provide a matrix that eliminated nonspecific absorption of proteins. The method of entrapping molecules was modified to increase the proportion of entrapped molecules that retained their reactivity. Protein A was entrapped in the modified sol-gel glass column and used to purify IgG from sheep sera by affinity chromatography. The purity of the IgG, as determined by SDS-PAGE, was comparable to that obtained from commercially available protein A columns and, if the capacity of the column was not exceeded, the yield approached 100%. Although the quality and quantity of the yields were comparable, the methodology described herein can be accomplished more rapidly and with greater ease. Furthermore, the sol-gel glass ligand preparation is extremely stable and can be reused for isolation of gamma-globulin. The technique has great potential for isolating macromolecules utilizing various ligands.

Once-daily fosinopril in the treatment of hypertension

This multicenter, dose-ranging study evaluated the antihypertensive effectiveness of once-daily administration of fosinopril sodium in 220 patients with supine diastolic blood pressure of 95-115 mm Hg. After a 4-week placebo period, patients were randomly assigned to double-blind therapy with either placebo or 10, 40, or 80 mg fosinopril once daily for 4 weeks. If treatment goals were not met, chlorthalidone 25 mg/day was added for weeks 5 to 8. Thereafter, patients could enter the long-term, open-label phase and receive 10-80 mg/day fosinopril plus chlorthalidone, if needed. After 4 weeks of monotherapy, the average decreases in supine diastolic blood pressure were 9% (10 mg), 11.5% (40 mg), and 12.5% (80 mg) compared with 6% in the placebo group. After 8 weeks, the average decreases, with or without diuretic therapy, were 12.5-18.2%, compared with 10.8% with placebo. Blood pressure continued to be well controlled, and the patients showed no evidence of tachyphylaxis or tolerance through 12-15 months of treatment. Fosinopril was well tolerated. During the short-term phase, no patient withdrew because of adverse events possibly related to fosinopril; during the long-term phase, nine of 148 patients (6.1%) withdrew for that reason. In patients with mild-to-moderate hypertension, once-daily fosinopril (40 and 80 mg) provided significant antihypertensive effects with or without diuretic therapy. The 10 mg dose was effective in some patients and may be considered a starting dose.

Diltiazem and captopril alone or in combination for treatment of mild to moderate systemic hypertension

The efficacy and safety of sustained-release diltiazem, 60 to 180 mg twice daily, was compared with that of captopril, 25 to 75 mg twice daily, alone and in combination, in 132 patients with mild to moderate essential hypertension (supine diastolic blood pressure [BP] 95 to 114 mm Hg). All patients received placebo for 4 to 6 weeks, followed by randomization to diltiazem or captopril during the double-blind monotherapy phase. Either study drug was titrated over 6 weeks to achieve a goal supine diastolic BP reduction of at least 10 mm Hg and a diastolic BP of less than 90 mm Hg. Patients achieving the goal BP reduction were maintained on monotherapy for an additional 8 weeks. Patients not achieving the treatment goal after 8 weeks with either drug alone received the other drug in combination, titrated to achieve goal BP response. Both drugs lowered BP significantly and, at the doses used, diltiazem had a greater effect on diastolic BP than did captopril. The mean changes from baseline at week 8 were -10.6 and -7.3 mm Hg, respectively, (p = 0.01). Goal BP was achieved in 38% of patients taking diltiazem monotherapy and in 34% of patients taking captopril monotherapy. There were no significant differences between diltiazem and captopril in diastolic or systolic BP reductions by race or age. The addition of alternate therapy for non-goal achievers at week 8 resulted in significant reductions in diastolic and systolic BP by week 16.(ABSTRACT TRUNCATED AT 250 WORDS)

A randomized, blinded, placebo-controlled trial of recombinant human tissue-type plasminogen activator in patients with unstable angina pectoris

Twenty-four patients with unstable angina pectoris, defined as chest pain at rest with transient ST segment deviation of at least 1 mm, were randomly assigned to blinded treatment with either placebo or intravenous recombinant human tissue-type plasminogen activator (rt-PA). Before randomization, all patients were treated with oral beta-blockers, calcium antagonists, nitrates, and continuous intravenous heparin for a monitoring period of 12 to 28 hr. After this monitoring period the 24 patients were randomly assigned to receive either placebo or 1.75 mg/kg intravenous rt-PA given over 12 hr at a rate of 0.75 mg/kg over 1 hr, 0.5 mg/kg over 4 hr, and 0.5 mg/kg over 7 hr. One patient, assigned to receive placebo, developed acute myocardial infarction after randomization but before receiving the study drug. Ischemic events were recorded during a hospital follow-up period of at least 4 days unless a further intervention was indicated or the coronary angiogram was normal. The follow-up period was 7 +/- 5 days (mean +/- SD) after the placebo infusion and 8 +/- 4 days after the infusion of rt-PA. Unstable angina pectoris persisted after the completion of the infusion in six of 11 patients receiving placebo and only one of 12 patients receiving rt-PA (p less than .03). Coronary angiography, performed 38 +/- 19 hr after the infusion, demonstrated subocclusive thrombus in eight of 11 patients receiving placebo but in none of 11 patients treated with rt-PA (p less than .002). One patient on rt-PA refused coronary angiography.(ABSTRACT TRUNCATED AT 250 WORDS)

Comparison of nifedipine and propranolol used in combination with diuretics for the treatment of hypertension

One hundred patients participated in a double-blind, randomized study to compare the antihypertensive efficacy of sustained-release nifedipine and propranolol in hypertensive patients whose diastolic blood pressure exceeded 95 mm Hg while receiving diuretic therapy. Nifedipine (mean dose, 79.6 mg per day) decreased blood pressure by 11.4/10.5 mm Hg; propranolol (mean dose, 198.4 mg per day) decreased blood pressure by 13.5/10.3 mm Hg. Reduction of diastolic blood pressure to below 90 mm Hg was achieved in 63 percent of nifedipine-treated patients and in 57 percent of propranolol-treated patients. Nifedipine therapy was associated with an increase in high-density lipoprotein cholesterol levels and a decrease in serum triglyceride levels. In contrast, propranolol therapy was associated with a decrease in high-density lipoprotein cholesterol levels and an increase in serum triglyceride levels. Nifedipine is as effective as propranolol in the treatment of patients with mild to moderate hypertension whose blood pressure is inadequately controlled by diuretic therapy.

Suppressed anger and blood pressure: the effects of race, sex, social class, obesity, and age

We studied 572 men and women who participated in a blood pressure screening program at a government unemployment office. Before having their blood pressures taken, the subjects completed a brief questionnaire that included two items measuring conflict over anger expression. Information was also obtained on obesity, race, sex, social class, and age. Across all subjects, systolic blood pressure was found to be significantly related to suppressed anger (p less than 0.016). Normotensive were twice as likely as hypertensives to be free of suppressed anger. This relationship remained after controlling for the covariates of age, social class, and obesity. The relationship between suppressed anger and systolic blood pressure was significant for white men, exhibited a trend in black men, and was not significant for women. In contrast to the systolic findings, suppressed anger was unrelated to diastolic pressure in all the analyses.

Is renin a factor in the etiology of essential hypertension?

The widespread clinical study of converting-enzyme inhibitors has shown that they are effective antihypertensive drugs even in patients who may manifest either normal or decreased plasma renin activity. This suggests either that renin in a site other than plasma may play a contributory role in essential hypertension or that the hypotensive effect is caused by increased concentrations of kinins and prostaglandins, both demonstrated consequences of converting-enzyme inhibitor administration. Specific renin inhibitors appropriate for studies in humans would aid in the resolution of this question. Four classes of compounds have been demonstrated to be renin inhibitors of high potency: specific antibody, general peptide inhibitors of acid proteases, analogs of angiotensinogens, and peptides that are related to the amino-terminal sequence of prorenin. With the purification of renin, specific polyclonal or monoclonal antibodies have become available. The former have already been used extensively in physiologic studies in intact animals. Pepstatin is an inhibitor of many acid proteases. Its in vivo application has been retarded by its relative insolubility, but recent chemical modifications, particularly the addition of charged amino acids at the carboxy terminus, have rendered it more useful. The minimal substrate for renin is an octapeptide segment of the protein substrate: His-Pro-Phe-His-Leu-Leu-Val-Tyr. Variants of this sequence have resulted in competitive inhibitors that are useful in vivo. Recently, remarkably active inhibitors have been synthesized by reducing the peptide bond that is cleaved by renin, producing what may be a transition state inhibitor.(ABSTRACT TRUNCATED AT 250 WORDS)

Role of prostaglandin E (PGE) in the modulation of the action of vasopressin on water flow in the urinary bladder of the toad and mammalian kidney

PGE1 and PGE2 are known to interfere with the water permeability effect of vasopressin in toad bladder and kidney. It has been proposed that endogenous prostaglandin E (PGE), synthesized within cells of vasopressin-sensitive tissues, serves to modulate the permeability changes elicited by the neurohypophyseal hormone. Direct evidence in support of this hypothesis is as follows: vasopressin increases the biosynthesis of PGE2 in renal interstitial cells and in isolated toad bladder. In the latter, inhibition of vasopressin-induced synthesis of PGE by a variety of inhibitors results in a greater water permeability response to vasopressin. It appears that vasopressin has two effects in toad bladder and kidney: (i) it activates adenylate cyclase thereby increasing the concentration of adenosine 3',5' monophosphate (cyclic AMP), the nucleotide responsible for the resultant increase in water permeability; and (ii) it activates a phospholipase that serves to release arachidonic acid, the precursor of PGE2 from intracellular pools. The PGE derived from the arachidonic acid diminishes adenylate-cyclase activity, in consequence of which the response of the enzyme to vasopressin is modulated.