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.

Abstract 031: Thresholds for Defining Home Blood Pressure Elevation Among US adults

Background: Most hypertension guidelines have recommended lower home than clinic BP thresholds based on epidemiological studies conducted in non-US populations. However, diagnostic thresholds to define home BP elevation have never been determined in the general population in the United States.

Methods: We analyzed data from 2 US cohorts with home and clinic BP data in the same participants, the Dallas Heart Study (DHS, n=5,768) and the North Carolina Masked Hypertension study (NCMH, n = 420). Home BP thresholds for stage 1 (BP ≥ 130/80 mmHg) and stage 2 hypertension (BP ≥ 140/90 mmHg) were identified using a regression-based approach in both cohorts and an outcome-derived approach in the DHS cohort. The composite of all-cause mortality or a cardiovascular disease (CVD) event was used in the outcome-derived approach. For this approach, BP thresholds were identified only for systolic BP (SBP) as clinic diastolic BP (DBP) was not associated with the outcome.

Results: Among untreated participants in DHS, the regression-derived thresholds for home BP corresponding to clinic BP for stage 1 and stage 2 hypertension were 130/81 and 137/88 mmHg in blacks and 127/79 and 135/86 mmHg in nonblacks, respectively. The results are virtually identical in the NCMH cohort. The 11-year composite CVD and mortality events corresponding to stage 1 (clinic SBP ≥ 130) and stage 2 (clinic SBP ≥ 140 mmHg) were higher in untreated blacks than untreated non-blacks [13.3 (11.06-15.54) and 17.59 (14.8-20.37)% vs. 6.78 (5.17-8.39) and 9.86 (6.94-12.77)%, respectively]. Using a race/ethnicity-specific composite outcome, the outcome-derived thresholds from the DHS for home SBP corresponding to stage 1 and stage 2

hypertension were 131 and 140 mmHg in untreated blacks and 130 and 139 mmHg in untreated nonblacks, respectively.

Conclusions: Based on the regression-derived approach, we found home BP thresholds for stage 1 and 2 hypertension from both cohorts to be similar to the current ACC/AHA guidelines. The outcome-derived approach also identified similar home SBP thresholds for stage 1 hypertension but slightly higher home SBP thresholds for stage 2 hypertension than recommended guidelines.

Abstract P191: Improved Systolic and Diastolic Blood Pressure After Enhanced External Counterpulsation Therapy Combined With a Lifestyle Modification Program

Background: Enhanced external counterpulsation (EECP) is a noninvasive, FDA approved therapy for refractory angina. Because EECP increases nitric oxide release, it may have an ancillary benefit on blood pressure (BP).

Methods: We measured changes in BP at baseline over 35 sessions of EECP, which included lifestyle coaching. Supine blood pressure was measured before and after every EECP session by trained healthcare technicians with calibrated manual sphygmomanometers.

Results: 404 patients (age 67.2 ± 10.0, 50% male - 200/404, 77% African American - 311/404) completed the program. Hypertensive subjects at baseline (37% - 150/404) showed an improvement in both systolic and diastolic BP (Table). Notably, there was a marked reduction in BP after the first EECP session, with a further, more modest reduction by the end of the 35 sessions. Weight decreased by a mean 3.0 lbs (p<0.001) and there was no significant difference in the number of patients receiving antihypertensive medications before or after completing EECP (46% - 184/404 vs. 47% - 189/404, p=0.62).

Conclusions: EECP therapy leads to a reduction in both systolic and diastolic blood pressure, which is most prominent in patients with baseline hypertension. These results maintain throughout the 35 sessions. These results reflect observational data from one highly experienced clinic in which EECP is routinely combined with daily coaching on vegan plant-based lifestyle modifications and exercise. Further studies are indicated to investigate this observed phenomenon to both confirm these findings as well as assess for the length and durability of the effect.

Simultaneous noninvasive recording of skin sympathetic nerve activity and electrocardiogram

BACKGROUND

Sympathetic nerve activity is important to cardiac arrhythmogenesis.

OBJECTIVE

The purpose of this study was to develop a method for simultaneous noninvasive recording of skin sympathetic nerve activity (SKNA) and electrocardiogram (ECG) using conventional ECG electrodes. This method (neuECG) can be used to adequately estimate sympathetic tone.

METHODS

We recorded neuECG signals from the skin of 56 human subjects. The signals were low-pass filtered to show the ECG and high-pass filtered to show nerve activity. Protocol 1 included 12 healthy volunteers who underwent cold water pressor test and Valsalva maneuver. Protocol 2 included 19 inpatients with epilepsy but without known heart diseases monitored for 24 hours. Protocol 3 included 22 patients admitted with electrical storm and monitored for 39.0 ± 28.2 hours. Protocol 4 included 3 patients who underwent bilateral stellate ganglion blockade with lidocaine injection.

RESULTS

In patients without heart diseases, spontaneous nerve discharges were frequently observed at baseline and were associated with heart rate acceleration. SKNA recorded from chest leads (V₁-V₆) during cold water pressor test and Valsalva maneuver (protocol 1) was invariably higher than during baseline and recovery periods (P < .001). In protocol 2, the average SKNA correlated with heart rate acceleration (r = 0.73 ± 0.14, P < .05) and shortening of QT interval (P < .001). Among 146 spontaneous ventricular tachycardia episodes recorded in 9 patients of protocol 3, 106 episodes (73%) were preceded by SKNA within 30 seconds of onset. Protocol 4 showed that bilateral stellate ganglia blockade by lidocaine inhibited SKNA.

CONCLUSION

SKNA is detectable using conventional ECG electrodes in humans and may be useful in estimating sympathetic tone.

Target Organ Complications and Cardiovascular Events Associated With Masked Hypertension and White-Coat Hypertension: Analysis From the Dallas Heart Study

BACKGROUND

Multiple epidemiological studies from Europe and Asia have demonstrated increased cardiovascular risks associated with isolated elevation of home blood pressure (BP) or masked hypertension (MH). Previous studies have not addressed cardiovascular outcomes associated with MH and white-coat hypertension (WCH) in the general population in the United States.

OBJECTIVES

The goal of this study was to determine hypertensive target organ damage and adverse cardiovascular outcomes associated with WCH (high clinic BP, ≥140/90 mm Hg; normal home BP, <135/85 mm Hg), MH (high home BP, ≥135/85 mm Hg; normal clinic BP, <140/90 mm Hg), and sustained hypertension (high home and clinic BP) in the DHS (Dallas Heart Study), a large, multiethnic, probability-based population cohort.

METHODS

Associations among WCH, MH, sustained hypertension, and aortic pulsed wave velocity by magnetic resonance imaging; urinary albumin-to-creatinine ratio; and cystatin C were evaluated at study baseline. Then, associations between WCH and MH with incident cardiovascular outcomes (coronary heart disease, stroke, atrial fibrillation, heart failure, and cardiovascular death) over a median follow-up period of 9 years were assessed.

RESULTS

The study cohort comprised 3,027 subjects (50% African Americans). The sample-weighted prevalence rates of WCH and MH were 3.3% and 17.8%, respectively. Both WCH and MH were independently associated with increased aortic pulsed wave velocity, cystatin C, and urinary albumin-to-creatinine ratio. Both WCH (adjusted hazard ratio: 2.09; 95% confidence interval: 1.05 to 4.15) and MH (adjusted hazard ratio: 2.03; 95% confidence interval: 1.36 to 3.03) were independently associated with higher cardiovascular events compared with the normotensive group, even after adjustment for traditional cardiovascular risk factors.

CONCLUSIONS

In a multiethnic U.S. population, both WCH and MH were independently associated with increased aortic stiffness, renal injury, and incident cardiovascular events. Because MH is common and associated with an adverse cardiovascular profile, home BP monitoring should be routinely performed among U.S. adults.

Renal denervation therapy for hypertension: pathways for moving development forward

This scientific statement provides a summary of presentations and discussions at a cardiovascular Think Tank co-sponsored by the American Society of Hypertension (ASH), the United States Food and Drug Administration (FDA), and the National Heart, Lung, and Blood Institute (NHLBI) held in North Bethesda, Maryland, on June 26, 2014. Studies of device therapies for the treatment of hypertension are requested by regulators to evaluate their safety and efficacy during their development programs. Think Tank participants thought that important considerations in undertaking such studies were: (1) Preclinical assessment: how likely it is that both efficacy and safety data indicating benefit in humans will be obtained, and/or whether a plausible mechanism of action for efficacy can be identified; (2) Early human trial(s): the ability to determine that the device has an acceptable benefit-to-risk balance for its use in the intended patient population and without the influence of drug therapy during a short-term follow-up period; and (3) Pivotal Phase III trial(s): the ability to prove the effectiveness of the device in a broad population in which the trial can be made as non-confounded as possible while still allowing for the determination for benefits when added to antihypertensive therapies.

Abstract 16015: Exosome-mediated Reversal of Duchenne Cardiomyopathy

Duchenne muscular dystrophy, a crippling genetic disease leading to premature death, affects the heart as well as skeletal muscle. Indeed, cardiomyopathy is the leading cause of death in Duchenne patients. There are no approved treatments for the cardiomyopathy, and novel Duchenne-specific experimental approaches such as exon skipping do not benefit the heart. Here we demonstrate that cardiosphere-derived cells (CDCs), which are in advanced clinical testing for therapeutic regeneration after myocardial infarction, reverse the key pathophysiological hallmarks of Duchenne cardiomyopathy (oxidative stress, inflammation, fibrosis and mitochondrial dysfunction) in mdx mice. Exosomes secreted by human CDCs reproduce the benefits of CDCs in mdx mice, and reverse mitochondrial dysfunction in human Duchenne cardiomyocytes. Both CDCs and their exosomes improve heart function in mdx mice (P<0.05); a single injection of CDCs suffices to increase maximal exercise capacity and improve survival (P<0.005). Delivery of a microRNA enriched in CDC exosomes, miR 148a, mimics key effects of CDCs and CDC exosomes. Thus, CDCs effectively treat Duchenne cardiomyopathy, via exosome-mediated transfer of signaling molecules including miR 148a. The present findings motivate clinical testing of CDCs in patients with Duchenne cardiomyopathy.

Physician underutilization of effective medications for resistant hypertension at office visits in the United States: NAMCS 2006-2010

BACKGROUND

The American Heart Association (AHA) published guidelines for treatment of resistant hypertension in 2008 recommending use of thiazide diuretics (particularly chlorthalidone), aldosterone antagonists, and fixed-dose combination medications, but it is unclear the extent to which these guidelines are being followed.

OBJECTIVE

To describe trends in physician use of recommended medications for resistant hypertension and assess variations in medication use based on geography, physician specialty and patient characteristics.

DESIGN

Cross-sectional analysis using the National Ambulatory Medical Care Survey from 2006 to 2010.

STUDY SAMPLE

We analyzed visits of hypertension patients to family physicians, general internists, and cardiologists. Resistant hypertension was defined as concurrent use of ≥ 4 classes of blood pressure (BP) medications or elevated BP despite the use of ≥ 3 medications. Pregnant patients and visits with diagnosed heart failure or end-stage renal disease were excluded.

MAIN OUTCOME

Use of AHA-recommended medications for management of resistant hypertension.

RESULTS

Of 19,500 patient visits with hypertension, 1,567 or 7.1 % CI (6.6-7.7 %) met criteria for resistant hypertension. Thiazide diuretic use was reported in 58.9 % of visits pre-guidelines vs. 54.8 % post-guidelines (p = 0.37). Use of aldosterone antagonists was low and also did not change significantly after guideline publication (3.1 % vs. 4.5 %, p = 0.27). Fixed-dose combinations use was 42.0 % before and 37 % after guideline publication (p = 0.29). Each 10-year increase in patient age was associated with lower thiazide use (OR 0.87, CI 0.77-0.97), as was presence of comorbid ischemic heart disease (OR 0.62, CI 0.41-0.94). Medication use did not vary by geography or physician specialty.

CONCLUSION

Use of AHA-recommended medications for resistant hypertension remains low after publication of guidelines. Healthcare systems should encourage more frequent prescribing of these medications to improve care in this high-risk population.

Opportunistic pathogens relative to physicochemical factors in water storage tanks

Household water in Oman, as well as in other countries in the region, is stored in tanks placed on house roofs that can be subjected to physicochemical factors which can promote microbial growth, including pathogens and opportunistic pathogens which pose health risks. Water samples were collected from 30 houses in a heavily populated suburb of Muscat. The tanks used were either glass reinforced plastic (GRP), polyethylene or galvanised iron (GI). Heterotrophic bacteria, coliforms, faecal coliforms and iron sulphur bacteria varied significantly in the three tanks. Yeast and mould count showed significant variations. Isolation of Aeromonas spp., fluorogenic and pathogenic Pseudomonas, Pasteurella, Salmonella, Serratia and Tatumella, and Yersinia and Legionella in biofilms varied in the three tanks. The fungi isolates in the three tanks were Penicillium, Cladosporium and Aspergillus. Nephelometric turbidity unit, threshold odour number and free chlorine varied significantly in the three tanks. True colour unit values did not show a significant difference; however, GRP tanks had algae, autotrophic and pigmented microorganisms. In addition, GI tanks had sediments and corrosion. The results of this investigation are important to evaluate the status of the present household water tanks in countries with high annual temperatures, which may affect public health.

Effects of pesticide temephos on the gills of Aphanius dispar (Pisces: Cyprinodontidae)

The changes in the behavior of Aphanius dispar, a cyprinodont fish when exposed to different concentrations of temephos, an organophosphorus pesticide widely used to control mosquito larvae in aquatic habitats are noted. The histopathology of gills exposed to temephos is studied in detail using light microscopy (LM), transmission electron microscopy (TEM) and scanning electron microscopy (SEM). The gill lesions were seen in all exposed concentrations of 1, 5, 10 and 25 ppm and the magnitude of the damage increased with the increase in concentrations. The most adverse effects of temephos are the destruction of cartilage and the large-scale cell death. Other effects included the degradation of chloride cells (CCs), desquamation, epithelial lifting, hypertrophy and lamellar fusion. The histological changes of microridges did not follow a consistent pattern in exposed concentrations. However, lamellar curling and collapsing was common in all exposed fish.

Adiposity-independent sympathetic activity in black men

Obesity is thought to lead to sympathetic overactivity as a compensatory adjustment to weight gain. However, most of the experimental support for the hypothesis has been derived from white cohorts. Our previous study in blacks indicated that sympathetic nerve activity (SNA) is closely correlated with body mass index only in women, whereas, in black men, SNA is elevated and dissociated from adiposity (Abate et al., Hypertension 38: 379-383, 2001). To further determine whether total and regional adiposity are determinants of SNA in blacks, we performed a prospective weight loss study in 12 normotensive obese black men and 9 obese black women. SNA, body mass index, and abdominal fat mass were measured before and 16 wk after hypocaloric diet. The major new findings are that, in obese black men, the dietary-induced weight loss of 11.3+/-0.8 kg resulted in reduction in plasma leptin, insulin, and visceral abdominal fat but had no effect on SNA (from baseline of 26+/-4 to 28+/-3 bursts/min, P=not significant). In contrast, in black women, weight loss of 8.0+/-0.9 kg caused similar reductions in plasma leptin, insulin, and visceral abdominal fat and led to a reduction in SNA by 40% (from baseline of 22+/-2 to 13+/-3 bursts/min, P<0.05). In conclusion, these new data from this prospective study provide strong support for a major adiposity-independent sympathetic activity in black men and adiposity-related sympathetic activity in black women.

Amlodipine/Atorvastatin single-pill therapy for blood pressure and lipid goals in African Americans: influence of the metabolic syndrome and type 2 diabetes mellitus

African Americans with diabetes +/- the metabolic syndrome are at high risk for cardiovascular disease. This subanalysis of the Clinical Utility of Caduet in Simultaneously Achieving Blood Pressure and Lipid End Points (CAPABLE) trial studied attainment of the Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure (JNC 7) and the National Cholesterol Education Program Adult Treatment Panel III (NCEP ATP III) blood pressure (BP) and low-density lipoprotein cholesterol (LDL-C) goals by 8 flexibly titrated doses (5/10-10/80 mg) of amlodipine/atorvastatin single pill in 494 African Americans with hypertension and dyslipidemia, according to the presence of diabetes +/- the metabolic syndrome. In 169 diabetic patients, the metabolic syndrome was associated with poorer BP goal attainment (38.5% vs 48.5% in diabetic patients without the metabolic syndrome). Among diabetic patients (+/- the metabolic syndrome) 61% to 62% reached LDL-C goal. More than 60% of patients with diabetes uncontrolled for LDL-C were maintained on suboptimal atorvastatin therapy (mean final dose: 29.9 mg vs maximum of 80 mg). Reluctance to intensify therapy to attain accepted targets in high-risk individuals suggests a degree of clinical inertia not explained by objective evidence of dose-dependent intolerance.

Improved attainment of blood pressure and cholesterol goals using single-pill amlodipine/atorvastatin in African Americans: the CAPABLE trial

OBJECTIVE

To investigate the efficacy and safety of single-pill amlodipine/atorvastatin therapy for the simultaneous treatment of hypertension (HTN) and dyslipidemia in African Americans.

PATIENTS AND METHODS

Conducted between July 19, 2004, and August 9, 2005, the Clinical Utility of Caduet in Simultaneously Achieving Blood Pressure and Lipid End Points trial was a 20-week, open-label, noncomparative, multicenter trial of the efficacy and safety of single-pill amlodipine/atorvastatin in controlling elevated blood pressure (BP) and low-density lipoprotein cholesterol (LDL-C) in African Americans with concomitant HTN and dyslipidemia and either no additional risk factors, 1 or more cardiovascular risk factors, or coronary heart disease or a risk equivalent. Eight dosage strengths of single-pill amlodipine/atorvastatin were flexibly titrated. The primary efficacy assessment of the main trial was the percentage of patients who attained the LDL-C treatment goals of both the Seventh Report of the Joint National Committee on the Prevention, Detection, Evaluation, and Treatment of High Blood Pressure and the National Cholesterol Education Program Adult Treatment Panel III.

RESULTS

Of the 1170 African American patients screened, 501 were enrolled in the study and 499 received drug therapy. At end point, 236 (48.3%) of 489 patients reached both their BP and LDLC goals (vs 4 [0.8%] of 484 at baseline); 280 (56.8%) of 493 reached BP goals (vs 7 [1.4%] of 494 at baseline); and 361 (73.7%) of 490 reached LDL-C goals (vs 138 [28.5%] of 484 at baseline). Among the 499 patients receiving drug therapy, common treatment-related adverse events were peripheral edema (17 patients [3.4%]), headache (11 [2.2%]), myalgia (11 [2.2%]), and constipation (10 [2.0%]).

CONCLUSION

Single-pill amlodipine/atorvastatin therapy was well tolerated and effectively targeted HTN and dyslipidemia in this population of African Americans who were at risk of cardiovascular disease.

Primary hyperaldosteronism: effect of adrenal vein sampling on surgical outcome

HYPOTHESIS

Adrenal vein sampling is superior to computed tomography for subtype differentiation of primary hyperaldosteronism.

DESIGN

Retrospective review.

SETTING

University medical center.

PATIENTS

Forty-eight patients (32 men and 16 women) with biochemically confirmed primary hyperaldosteronism.

MAIN OUTCOME MEASURES

We compared demographic factors, results of biochemical and imaging studies (computed tomography and adrenal vein sampling), therapy, and patient outcomes.

RESULTS

Mean +/- SEM adrenal nodule size was 1.54 +/- 0.2 cm. Adrenal vein sampling was performed in 41 (85%) of 48 patients, and it was successful in 39 (95%) of those 41 patients. Concordance between computed tomography and adrenal vein sampling was observed in 22 (54%) of the 41 patients. Thirty-two patients underwent successful laparoscopic adrenalectomy. There was 1 complication and no deaths. All 32 patients were cured of hypokalemia.

CONCLUSION

Adrenal vein sampling is superior to image-based techniques for subtype differentiation of primary hyperaldosteronism.

Secondary Hypertension—Whom and How Do You Study? What Type of Therapy Is Appropriate?

Following a hypertension symposium in Los Angeles, CA on October 20, 2004, a roundtable was convened to discuss secondary or treatable forms of high blood pressure, when and whom should be studied, and treatment methods. Dr. Marvin Moser, Clinical Professor of Medicine at Yale University School of Medicine, New Haven, CT, moderated the panel discussion. Participants included Dr. Ron Victor, from the Southwestern Medical Center, Dallas, TX and Dr. Joel Handler of the Orange County Kaiser Permanente Hypertension Clinic, Anaheim, CA.

Association between chronic kidney disease and coronary artery calcification: the Dallas Heart Study

The hypothesis that chronic kidney disease (CKD) is associated with increased coronary artery calcification (CAC) was tested using data from the Dallas Heart Study, a representative sample of Dallas County residents aged 30 to 65 yr. CKD was defined as presence of microalbuminuria and GFR > or =60 ml/min per 1.73 m(2) (stage 1 to 2), or GFR <60 ml/min per 1.73 m(2) (stage 3 to 5), excluding end-stage kidney disease. Logistic regression was used to examine the association between stages of CKD and CAC scores >10, >100, and >400 versus scores < or =10 compared with no CKD while adjusting for covariates. Analyses were repeated after stratifying by presence of diabetes. The mean age was 43.9 yr, and hypertension and diabetes were noted in 31.0 and 9.8%, respectively. No association was noted between stage 1 to 2 CKD and increased CAC scores. Compared with no CKD, stage 3 to 5 CKD was associated with CAC scores >100 (odds ratio, 2.85; 95% confidence interval, 0.92 to 8.80) and >400 (odds ratio, 8.35; 95% confidence interval, 1.94 to 35.95) in the total population after adjustment for covariates, but these associations were substantially reduced after exclusion of participants with diabetes. Participants with diabetes and stage 3 to 5 CKD had a ninefold increased odds of CAC scores >10 versus scores < or =10 compared with participants with diabetes and without CKD, whereas no association was noted between stage 3 to 5 CKD and CAC scores >10 in the nondiabetic population. In conclusion, stage 3 to 5 CKD is associated with increased CAC scores, but this association may be substantially stronger among adults with diabetes. These findings need to be confirmed in study populations that include adults >65 yr of age and a larger number of CKD cases.

Evaluation of the mercury exposure of dental amalgam patients by the Mercury Triple Test

AIMS

To establish and analyse reference data for the mercury burden of patients with and without amalgam fillings.

METHODS

Atomic absorption spectroscopy was used to quantify Hg concentrations in the scalp hair and urine (before and after application of dimercaptopropane sulphonate), and Hg release from dental amalgams (using a newly developed, amalgam specific chew test), in 2223 subjects.

RESULTS

50th centiles were 1.3 microg Hg/g creatinine in basal urine, 32 microg Hg/g creatinine after DMPS application, 454 ng Hg/g in hair, and 27 microg Hg per g of chewing gum, which corresponds to about 1 micro g Hg released per minute of chewing. Total Hg intake (from ambient air, drinking water, food, and amalgams) of most patients is well below the provisioned tolerable weekly intake (PTWI) defined by the WHO, unless extremely Hg rich food is consumed on a regular basis. However, for patients exceeding the 75th centile in chew tests, total Hg intake exceeds the PTWI by about 50%, even at the low limit of intake from food. In the absence of occupational exposure, significant Hg release from dental amalgams is a necessary but insufficient condition to obtain a high long term body burden. After removal of dental amalgams, chew tests no longer exhibit oral Hg exposure, while basal urine Hg content and DMPS induced excretion display a exponential decrease (half life about 2 months in both cases).

CONCLUSIONS

A standardised procedure for evaluation of the magnitude and origin of the Hg burden of individuals has been developed, which, by comparison with the database presented here for the first time, can serve as a diagnostic tool.

A modified thionin acridine-orange stain for mast cells

For in vitro studies in mesentery, toluidine blue and thionin dyes are generally used. We have tried thionin and acridine orange stains and found it to be good as it showed good colour contrast between mast cells and the background tissue. The two dyes were selected to give good colour contrast.

Ophthalmomyiasis in Oman: a case report and comments

A case of external ophthalmomyiasis caused by the first instar larvae of the sheep nasal botfly (Oestrus ovis) has been reported for the first time from the Sultanate of Oman, Southern Arabia. Sixty larvae were removed from the left eye of a 21-year-old male student, who acquired the infection during a field trip. The manual removal of larvae using a swab stick was the only effective treatment. The larval characteristics are described with illustrations, and the status of O ovis ophthalmomyiasis in the Middle East is discussed. The folk treatment administered for fly-mediated ophthalmomyiasis in Oman is also reported. Ophthalmomyiasis may not be a serious public health problem in Oman, but a nationwide survey of all myiases may be worthwhile.

Carabid beetle invasion of the ear in Oman

Two cases of human ear invasion by a predaceous beetle, Crasydactylus punctatus Guerin (Coleoptera; Carabidae), are reported from the Sultanate of Oman. The first case was that of a 35-year old woman who suffered a severe otologic injury caused by the biting and chewing of the external auditory canal and the tympanic membrane. The beetle then entered the middle ear and caused sensorineural hearing loss. The second case involved a 22-year-old male from whose ear a specimen of the same species was successfully removed after it was immobilized with 10% lidocaine spray. These cases are presented with discussion.

Human breast-cancer metastasis formation in a nude-mouse model: studies of hyaluronidase, hyaluronan and hyaluronan-binding sites in metastatic cells

Few animal models are available to study metastasis formation. The purpose of the present study was to obtain a useful model of metastasis formation in nude mice in an attempt to analyze the stroma reaction and in particular the production and the expression of hyaluronan (HA), hyaluronidase, and HA-binding sites by cultivated cells, and HA and hyaluronectin (HN) in the invasive areas of tumors. Nude mice were subjected to i.p. injections of several human cancer cell lines (PLC/PRF/5, HepG2, CB 191, CB 193, PC3, CAL 51, SA 87 and SA 98), and formation of metastases was analyzed in different organs (lung, liver, kidney, spleen and axillary nodes) by immunohistochemical techniques. CAL 51, a breast-cancer-metastasis-derived cell line with a normal karyotype, produced i.p. tumors in 75% animals and metastases in 90% animals (detected in the liver and axillary nodes). Two modes of invasion by CAL 51 cells were observed in the liver: one, direct, from the surface of the liver and the other, indirect, via the bloodstream. HA and HN were strongly expressed at the invasion areas. A cell line derived from hepatic metastasis of CAL 51 (HMD CAL 51) presented an abnormal karyotype. HMD CAL 51 produced more hyaluronidase (12-fold) and HA (10-fold) and expressed more CD44 (1.6-fold) and other HA-binding sites (9.5-fold) than the established cell line CAL 51. Our results show that i.p. injection of the CAL 51 cell line into nude mice provides a useful model of metastasis formation. The passage of the CAL 51 cells from the primary state to the metastatic state was characterized by a dramatic increase of HA and hyaluronidase production, and expression of HA, HN and HA-binding sites.

Activation and inhibition of human cancer cell hyaluronidase by proteins

Results regarding hyaluronidase activity in tumor extracts or cell lines are subject to variations according to the method used for the assay and, sometimes, within an assay. Hyaluronidase was assayed at pH 3.8 in the culture medium of the human cancer-derived cell lines SA87 and H460M by several techniques: HPLC, Reissig technique, ELSA technique, and zymographic analysis. The optimal pH was between 3.3 and 4 in solutions at constant 150 mM sodium concentration. The enzyme was reversibly inhibited by sodium concentration over 200 mM. The activity of purified hyaluronidase increased in the presence of low concentrations of the specific HA-binding glycoprotein hyaluronectin, or of bovine serum albumin or immunoglobulins, or of human albumin, transferrin, or hemoglobin, showing that proteins cooperate in enzyme activity. The ELSA technique showed that optimal pH was slightly lower in the presence of HN than that with BSA. The optimal BSA concentration was determined with the ELSA technique at 0.1 g/liter, and excess of either protein inhibited hyaluronidase. When measured with the Reissig technique, the activity of purified enzyme in the presence of 0.1 g/liter BSA was up to fourfold that without BSA. The cooperative effect of BSA was visualized by zymography. We conclude that the total protein content of hyaluronidase solutions must be considered to correctly interpret quantitation of the enzyme in sera or tissue extracts because protein concentrations above 200 microg/liter lead to underestimation of the enzyme.

[Production of hyaluronidase by cultured human tumor cells]

The presence of hyaluronidase was detected at pH 3.8 in eight out of twelve human cancer cell line culture media. Eight cell lines derived from primary tumours and four from metastases. In three culture media the enzymatic activity was lower than 0.035 pU/cell/h. In five others (in a hepatoma cell line and in four metastasis-derived cell lines) the activity was higher than 0.057 pU/cell/h. A tumour-derived fibroblast culture was negative. The optimal activity was observed at a pH comprised between 3.6 and 4. Salt inhibition of hyaluronidase was reversible. The enzyme was denaturated by a 10-min heating at 70 degrees C. The enzyme was not strictly specific for hyaluronan hydrolysis but also digested chondroitin sulfates. PH20, a spermatozoid protein that has homologies with the bee venom hyaluronidase, was not expressed by cell lines tested.

Factitious anisocoria and orthostatic hypotension

A 30-year-old woman employed by a veterinarian had many episodes of syncope. At presentation, she had anisocoria and premature ventricular beats. Hemodynamic workup revealed only moderate peripheral venous pooling. The circumstances of the fainting spells and eye examination led to the identification of medications which, if taken surreptitiously, will induce the perplexing clinical picture which the patient presented.

The effects of road and bridge construction on the bank-root macrobenthic invertebrates of a Southern Nigerian stream

A comparative study was conducted at three stations on a fourth order Nigerian stream to evaluate the effects of a road and bridge construction on the macrobenthic invertebrates of the bank-root biotope. Siltation and sedimentation appear to be the important factors affecting macroinvertebrates. At station 2, the construction site, there was a considerable reduction in the occurrence and abundance of invertebrate taxa; different groups of invertebrates showed varying responses to perturbational stress; the taxa richness, general diversity and evenness were also low. Irregular fluctuations in diversity and evenness suggested that the benthic community of station 2 was less stable than those of upstream and downstream stations. The concentrated dominance of Ephemeroptera and Coleoptera at station 2, despite low diversity, reflected the ability of a few tolerant taxa to occur there in high abundance. Faunal comparisons of the three stations confirmed the perturbational stress caused by construction activities.

Notes on the recovery of live ostracods from the gut of the white sucker (Catostomus commersoni Lacépède) 1808, (Pisces: Catostomidae)

Ten species of freshwater ostracods were ingested by Catostomus commersoni. Of these Physocypria pustulosa females were recovered alive from the gut and were able to reproduce. The possible significance of this observation to P. pustulosa dispersal is discussed.

Thermonuclease seroinhibition test for distinguishing Staphylococcus aureus from other coagulase-positive staphylococci

Since coagulase-positive staphylococci from animals are heterogeneous, another test is necessary to distinguish Staphylococcus aureus from them. Staphylococcal thermonucleases appear to be heterogeneous; antisera raised against S. aureus isolated from humans inhibit thermonuclease activity as demonstrated by the metachromatic well-agar diffusion method. The serological specificity of the thermonuclease elaborated by S. aureus of human origin was demonstrated using three antisera and 407 strains of staphylococci from diverse human and animal sources.

Effects of biofeedback and voluntary control procedures on heart rate and perception of pain during the cold pressor test

The effects of biofeedback training and voluntary control procedures on heart rate and subjective reactions to 30-sec immersion of the hand in ice water were investigated in five experimental conditions, nine subjects in each condition. All subjects were given an initial cold pressor test and a final test interspersed by the particular condition. In two of the conditions, subjects were given biofeedback training for increasing or for decreasing heart rate. No training was given to the other three groups. In two of the latter conditions, subjects were simply asked to increase or decrease their heart rate during the second cold pressor test, without previous training. The fifth condition was a no-treatment habituation control. Significant variations between groups were obtained of the tachycardia and reports of pain associated with the second cold pressor test. In general, there was a correspondence between heart rate change and subjective report of pain. Voluntary control of heart rate or other autonomically-mediated responses, enhanced by biofeedback training, may have implications for research on and clinical management of physiological and subjective reactions to stressful stimuli.