Wavelength dispersion of the local field intensity in silver-gold nanocages.

This study provides a combined theoretical and experimental analysis of the far-field (extinction) and of the near-field (SERS enhancement) spectral distribution in hollow nanoparticles, that is, silver-gold nanocages (NCs). Chitosan protected NCs have been synthesized by a galvanic replacement-based procedure: their morphological properties and chemical composition have been characterized by TEM, STEM and ICP. NCs were then functionalized with a thiolated organic dye prior to carrying out SERS measurements. Finite Element Method simulations of a single NC have shown that the field enhancement at the excitation wavelength follows the same spectral dependence as the extinction spectrum and, consequently, the SERS enhancement profile, as a function of the excitation wavelength, peaks at higher energy with respect to extinction. The simulated extinction is remarkably narrower than the experimental spectrum of NCs in solution, indicating that the colloidal sample is substantially polydispersed. However, a simple qualitative model that we have developed would suggest that the SERS enhancement profile is blue-shifted with respect to the extinction in the presence of polydispersivity as well. In addition, NC dimers have been simulated: both their extinction and near field-spectra shift to the red when the size of the gap is reduced analogous to what happens with dimers of filled spherical nanoparticles (NPs). In addition, simulations also revealed that a NC dimer is only slightly more efficient in amplifying the field with respect to the isolated NC, and this behavior is peculiar to NCs. In fact, filled spherical NP dimers exhibit a remarkably stronger field enhancement with respect to the isolated NP. By means of Wavelength Scanned SERS, we measured the spectral distribution of the local field in a dispersion of NCs. We observed experimentally that the local field is distributed in the same spectral region as the extinction and that the absolute value of the SERS enhancement factor maintains a low value throughout the range explored (568-800 nm). We propose that the observed correlation between the SERS profile and the extinction is accidental and originates from the limited increase in amplification provided by NC aggregates with respect to isolated NCs.

Losartan and amlodipine on myocardial structure and function: a prospective, randomized, clinical trial.

AIMS: To compare the effects of losartan and amlodipine on myocardial structure and function in hypertensive patients with Type 2 diabetes and left ventricular hypertrophy. METHODS: After a 4-week placebo period, patients were randomized to losartan 50 mg (n = 90) or amlodipine 5 mg (n = 91) for 12 months, with a doubling of the dose in patients who did not respond after 4 weeks. Blood pressure was measured in the clinic every month, while conventional echocardiography and acoustic densitometry (integrated backscatter analysis) were performed at the end of the placebo period and after 12 months of treatment. RESULTS: Both drugs reduced systolic/diastolic blood pressure to a comparable extent. Losartan significantly reduced left ventricular mass index (-19%, P < 0.001), interventricular septal thickness (-16.6%, P < 0.01) and left ventricular posterior wall thickness in diastole (-13.7%, P < 0.01). Amlodipine also decreased such measurements (-10%, P < 0.01 for left ventricular mass index, -9.3%, P < 0.05 for interventricular septal thickness in diastole and -10.1%, P < 0.05 for posterior wall thickness in diastole), but to a lesser extent than losartan. Both drugs significantly increased the ratio of peak filling velocity at early diastole to that at atrial contraction (E/A ratio) and decreased isovolumetric relaxation time: +13.7% and -8.5% with losartan,(both P < 0.01), and +7.9% and -4.9%, with amlopidine (both P < 0.05). Losartan, but not amlodipine, significantly reduced the relative integrated backscatter compared to baseline of the intraventricular septum (-10%, P < 0.01), and of the left ventricular posterior wall (-12%, P < 0.01), while increasing the cyclic variation of integrated backscatter of both the intraventricular septum (+35%, P < 0.001) and the left ventricular posterior wall (+32%, P < 0.001). CONCLUSIONS: Losartan provided a greater attenuation of left ventricular hypertrophy than amlodipine, seemingly as a result of a greater reduction of myocardial fibrosis.

Effects of aliskiren on QT duration and dispersion in hypertensive patients with type 2 diabetes mellitus.

AIM: To evaluate the effect of aliskiren compared to amlodipine on QT duration and dispersion in hypertensive patients with type 2 diabetes. METHODS: A total of 170 outpatients aged 50-75 years with mild to moderate hypertension (SBP >130 and <180 mmHg and DBP >80 and <100 mmHg) and type 2 diabetes were randomly treated with aliskiren 300 mg or amlodipine 10 mg, both given once daily for 24 weeks, according to a prospective, open label, blinded-end point, parallel group design. At the end of the placebo run-in, and after 12, and 24 weeks of treatment blood pressure (BP) measurements (by mercury sphygmomanometer, Korotkoff I and V), plasma biochemistry and a standard 12-lead surface ECG were evaluated. RESULTS: Both aliskiren and amlodipine significantly reduced systolic blood pressure (SBP)/diastolic blood pressure (DBP) values (-27.2/-14.3 mmHg, p < 0.001 vs. placebo and -27.8/-14.2 mmHg, p < 0.001 vs. placebo, respectively), with no statistical difference between the two drugs. Aliskiren, but not amlodipine, significantly reduced maximum QT interval (QTmax) (-14 ms at 12 weeks and -17 ms at 24 weeks, both p < 0.05 vs. placebo) and corrected QT max (QTc max) (-26 ms and -31 ms, p < 0.01) as well as the dispersion of both QT (-11 ms and -13 ms, p < 0.01) and QTc (-18 ms and -19 ms, p < 0.01). CONCLUSIONS: Despite similar BP lowering effect, aliskiren, but not amlodipine, reduced QT duration and dispersion, which might be related to the ability of aliskiren to interfere with mechanisms underlying myocardial electrical instability in the heart of diabetic hypertensive patients.

Different effects of aliskiren and losartan on fibrinolysis and insulin sensitivity in hypertensive patients with metabolic syndrome.

The aim of this study was to compare the effect of aliskiren and losartan on fibrinolysis and insulin sensitivity (IS) in hypertensive patients with metabolic syndrome. After 2-week placebo period, 76 outpatients with mild to moderate hypertension and metabolic syndrome were randomized to aliskiren 300 mg od or losartan 100 mg od for 12 weeks. Clinic blood pressure (BP), plasma PAI-1 antigen, and tPA activity were evaluated after 2, 4, 8, and 12 weeks of treatment. At the end of each treatment period patients performed an euglycemic hyperinsulinemic clamp and IS was assessed by glucose infusion rate (GIR). Both aliskiren and losartan induced a significant and similar SBP/DBP reduction (-15.6/10.7 mmHg and -15.5/10.5 mmHg, p<0.001 vs. baseline, respectively). Both drugs decreased PAI-1 antigen and activity after 2 weeks of treatment; subsequently, only the decreasing effect of aliskiren was sustained throughout the 12 weeks [-7.5 ng/ml (-31%) p<0.05 vs. baseline], while with losartan PAI-1 increased at week 12 [+3.6 ng/ml (+15%), p<0.05 vs. baseline and p<0.01 vs. aliskiren)]. The tPA activity showed no significant change with aliskiren and a decrease with losartan [-0.04 IU/ml (-8%), p<0.05 vs. baseline and p<0.01 vs. aliskiren]. Aliskiren significantly increased GIR [+1.4 mg/min/kg (+28%), p<0.01 vs. baseline] while losartan did not change it [+0.2 mg/min/kg (+4%), NS vs. baseline, p<0.05 vs. aliskiren)]. These results indicated that in this type of patients, despite similar BP reduction, aliskiren improved the fibrinolytic balance as well as IS, while losartan worsened the fibrinolytic balance and did not affect IS. The clinical relevance of these different effects remains to be clarified.

Metal oxalates in paints: a Raman investigation on the relative reactivities of different pigments to oxalic acid solutions.

One degradation phenomenon that occurs in artworks is the formation of metal oxalates on their surfaces. In order to gain insight into the inclination of pigments to produce oxalates, nine pigments including Na, Ca, Fe, Pb and Cu cations were selected to react with oxalic acid solutions at different concentrations (1 M, 0.1 M, 0.01 M and 0.005 M). Micro-Raman spectroscopy was used to detect the different reaction products. Pigments containing calcium (calcite, gypsum and Volterra gypsum) showed a high tendency to form weddellite as well as whewellite, especially at high acidic concentrations; among copper-based pigments (malachite, azurite, verdigris), the formation of moolooite was observed for high concentrations of acid and down to the lowest concentration (0.005 M) in the case of verdigris. Lead oxalate was detected on lead white. No iron oxalates were observed for hematite; the formation of calcium oxalate crystals was observed instead. Ultramarine blue reacted to produce elemental sulfur. According to the results obtained, calcite and verdigris showed the highest reactivity in oxalic acid environments, resulting in a high tendency to form calcium and copper oxalates, even at very low acidic concentrations; this behavior seems to arise from the high solubilities of these pigments in acidic environments.

Comparative effects of telmisartan and eprosartan on insulin sensitivity in the treatment of overweight hypertensive patients.

The aim of this study was to compare the effect of telmisartan and eprosartan on insulin sensitivity in overweight hypertensive patients. Fifty overweight (BMI > or = 25 and <30 kg/m (2)) outpatients, aged 41-65 years, with mild to moderate hypertension [systolic blood pressure (SBP) >140 and diastolic blood pressure (DBP) > or = 90 and < or = 110 mmHg], after a 4-week placebo period, were randomized to receive telmisartan 80 mg or eprosartan 600 mg for 8 weeks. Following another 4-week placebo period, patients were crossed to the alternative regimen for further 8 weeks. At the end of each placebo and active treatment period, blood pressure (BP), insulin sensitivity (by euglycemic hyperinsulinemic clamp), fasting plasma glucose (FPG), insulin (FPI), total cholesterol (TC), LDL-C, HDL-C, and triglycerides (Tg) were evaluated. Insulin sensitivity was expressed as the amount of glucose infused during the last 30 min (glucose infusion rate, GIR) in micromol/min/kg. Both telmisartan and eprosartan significantly reduced SBP/DBP values (by a mean of 19.4/13.3 mmHg and 17.9/12.1 mmHg respectively, all p<0.001 vs. placebo), with no significant difference between the two treatments. GIR was significantly increased by telmisartan (2.25+/-0.61 micromol/min/kg, p<0.05 vs. placebo) but not by eprosartan (0.25+/-0.14 micromol/min/kg, p=ns), the difference between the two drugs being statistically significant (p<0.02). No change in FPG, FPI, HDL-C, and Tg was observed with either treatment. Telmisartan significantly reduced TC (-9.9 mg/dl, -5%, p<0.04 vs. placebo) and LDL-C (-8.8 mg/dl, -7%, p<0.03 vs. placebo), whereas eprosartan did not influence them. These findings indicate a superiority regarding an improvement of insulin sensitivity and plasma lipid profile in overweight hypertensives by telmisartan as compared to eprosartan, possibly related to the selective stimulating PPAR-gamma property of telmisartan.

Effect of valsartan addition to amlodipine on ankle oedema and subcutaneous tissue pressure in hypertensive patients.

The aim of this study was to assess the effect of valsartan addition to amlodipine on ankle foot volume (AFV) and pretibial subcutaneous tissue pressure (PSTP), two objective measures of ankle oedema. After a 4-week placebo period, 80 grade 1-2 hypertensive patients (diastolic blood pressure (DBP)>90 mm Hg and <110 systolic blood pressure (SBP)>140 mm Hg) were randomized to amlodipine 10 mg or valsartan 160 mg or amlodipine 10 mg plus valsartan 160 mg for 6 weeks according to an open-label, blinded end point, crossover design. At the end of the placebo period and of each treatment period, blood pressure, AFV and PSTP were evaluated. AFV was measured using the principle of water displacement. PSTP was assessed connecting the subcutaneous pretibial interstitial environment with a water manometer. Both amlodipine and valsartan monotherapy significantly reduced SBP (-16.9 and -14.5 mm Hg, respectively, P<0.01 vs baseline), and DBP (-12.9 and -10.2 mm Hg, respectively, P<0.01 vs baseline) but the reduction was greater with the combination (-22.9 mm Hg for SBP, P<0.01 vs monotherapy; -16.8 mm Hg for DBP, P<0.01 vs monotherapy). Amlodipine monotherapy significantly increased both AFV (+23%, P<0.01 vs baseline) and PSTP (+75.5%, P<0.001 vs baseline) whereas valsartan monotherapy did not influence them. As compared to amlodipine alone, the combination produced a less marked increase in AFV (+6.8%, P<0.01 vs amlodipine) and PSTP (+23.2%, P<0.001 vs amlodipine). Ankle oedema was clinically evident in 24 patients with amlodipine and in six patients with the combination. These results suggest that angiotensin receptor blockers partially counteract the microcirculatory changes responsible for calcium channel blockers induced oedema formation.

Effect of telmisartan/hydrochlorothiazide vs lisinopril/hydrochlorothiazide combination on ambulatory blood pressure and cognitive function in elderly hypertensive patients.

The aim of this study was to compare the effects of telmisartan/hydrochlorothiazide (HCTZ) vs lisinopril/HCTZ combination on ambulatory blood pressure and cognitive function in elderly hypertensive patients. A total of 160 patients, 76 men and 84 women, aged 61-75 years, with sitting diastolic blood pressure (DBP)>90 mmHg and <110 mmHg and systolic blood pressure (SBP)>140 mmHg were randomized to receive temisartan 80 mg/HCTZ 12.5 mg o.d. or lisinopril 20 mg/HCTZ 12.5 mg o.d. for 24 weeks, according to a prospective, open-label, blinded end point, parallel-group design. At the end of a 2-week wash-out period and after 12 and 24 weeks of active treatment, 24-h noninvasive ambulatory BP monitoring (ABPM) was performed and cognitive function was evaluated through six different tests (verbal fluency, Boston naming test, word-list memory, word-list recall, word-list recognition and Trails B). Both treatments significantly reduced ambulatory BP. However, the telmisartan/HCTZ combination produced a greater reduction in 24-h, day-time and night time ABPM values. Lisinopril/HCTZ did not induce significant changes in any of the cognitive function test scores at any time of the study, whereas at both 12 and 24 weeks telmisartan/HCTZ significantly improved the word-list memory score (+17.1 and +15.7%, respectively, P<0.05 vs baseline), the word-list recall score (+13.5 and +16.9%, P<0.05) and the Trails B score (-33 and -30.5%, P<0.05). These results suggest that in elderly hypertensive patients treatment with telmisartan/HCTZ produces a slightly greater reduction in ambulatory BP than lisinopril/HCTZ combination and, unlike this latter, improves some of the components of cognitive function, particularly episodic memory and visuospatial abilities.

Hydrochlorothiazide added to valsartan is more effective than when added to olmesartan in reducing blood pressure in moderately hypertensive patients inadequately controlled by monotherapy.

This study was undertaken to evaluate the effects on blood pressure of hydrochlorothiazide (HCTZ) 12.5 mg added to valsartan 160 mg or to olmesartan 20 mg in hypertensive patients. After a 2-wk placebo period, 130 patients, aged 35 to 75 y, with diastolic blood pressure (DBP) >or=99 and 110 mm Hg were randomly assigned to olmesartan 20 mg once daily or to valsartan 160 mg once daily according to a prospective, parallel-arm study design. After 4 wk of monotherapy, patients whose BP was not controlled (DBP >or=90 mm Hg) were given combination treatment with HCTZ 12.5 mg for an additional 4 wk. At the end of the placebo period and at the end of each treatment period, clinical and ambulatory BP measurements were recorded. At the end of the combination therapy period, venous blood samples were drawn 2, 4, and 24 h after drug intake for evaluation of HCTZ plasma concentrations. Both combinations induced a greater ambulatory BP reduction than monotherapy. However, mean reduction from baseline in the valsartan/HCTZ-treated patients (-21.5)-14.6 mm Hg for 24 h, -21.8/-14.9 mm Hg for daytime, and -20.4/-13.7 mm Hg for nighttime systolic blood pressure [SBP]/DBP) was greater than in the olmesartan/HCTZ-treated patients )-18.8/-12.3 mm Hg for 24 h, -19.3/-12.8 mm Hg for daytime, and 17.4/-10.6 mm Hg for nighttime SBP/DBP). The difference between the effects of the 2 treatments was significant (P<.01). In particular, compared with monotherapy, the add-on effect of HCTZ 12.5 mg was significantly greater in the valsartan group than in those treated with olmesartan; the difference was more evident for nighttime BP values. Plasma concentrations of HCTZ were significantly greater with valsartan than with olmesartan at each determination time (P<.05). These findings suggest that the addition of HCTZ 12.5 mg to valsartan 160 mg monotherapy produces a greater BP reduction than the addition of the same dose of HCTZ to olmesartan 20 mg monotherapy.

Thromboembolic disease in hip replacement surgery.

Total hip replacement surgery carries the risk of thromboembolic complications, which could be fatal. Over the last three decades however, the risk has decreased considerably thanks to progress made in the understanding of the physiopathogenetic mechanism of thromboembolic disease and perioperative prophylaxis. It is the purpose of this study to discuss the main medical and surgical preventive measures that must be carried out before, during and immediately after surgery. The old concept of deciding thromboembolic prophylaxis after surgery is now obsolete.

Effects of captopril on cold pressor test responses in normotensive and hypertensive subjects.

The aim of this study was to evaluate the effects of short-term captopril administration on the response to cold pressor testing in normotensive and hypertensive subjects. Cold pressor testing was performed in 15 normotensive subjects and 15 hypertensive patients before and 90 minutes after captopril administration. Blood pressure and heart rate were measured before testing and at one-minute intervals from the beginning of cold pressor testing. Systolic time intervals were also assessed before and after testing. Captopril did not affect pressor responses to cold pressor testing in normotensive subjects or hypertensive patients. Basal heart rate (before testing) did not change, despite the decrease in blood pressure and showed a smaller increase in response to cold pressor testing in normotensive subjects, suggesting that captopril might interfere with arterial baroreflexes. The systolic time intervals were not modified by captopril except isometric contraction time; its basal value was reduced by captopril in both normotensive subjects and hypertensive patients. Cold exposure caused a similar increase in isometric contraction time before and after captopril in normotensive subjects, and the increase in isometric contraction time in hypertensive patients was greater. These findings suggest that captopril did not affect cardiac performance, indeed improving it, at least in basal conditions.

Occupational noise exposure and blood pressure.

OBJECTIVE: To investigate the relationship between occupational noise exposure and blood pressure. METHODS: We studied 8811 workers at a metallurgical factory, who were exposed to different levels of noise at the worksite: < or = 80 dB for 8078 workers and > 80 dB for 733 workers. A clinical examination, including measurements of blood pressure (by mercury sphygmomanometer, Korotkoff phases I and V), heart rate (by pulse palpation), body weight and height, was performed. The subjects were stratified into four age groups (18-30, 31-40, 41-50 and > 50 years) and into two body mass index groups: normal weight (< or = 25 kg/m2) and overweight (> 25 kg/m2). In order to eliminate possible confounding factors and statistical bias, a retrospective case versus control analysis was also carried out. RESULTS: The epidemiologic approach showed that the systolic blood pressure (SBP) but neither the diastolic blood pressure (DBP) nor the heart rate values were statistically higher in the group who were exposed to noise levels of > 80 dB, although the difference could be considered clinically relevant only in the older age group. The prevalence of hypertension (according to World Health Organization criteria) was higher among the workers who were exposed to the higher levels of noise. Stratification for body mass index confirmed the existence of a higher prevalence of hypertension in the exposed group. The results from the case versus control analysis indicated that both the SBP and the DBP levels in the exposed group were significantly higher than those in the reference group, and confirmed the existence of a higher prevalence of hypertension in the exposed group. CONCLUSIONS: The present data suggest that occupational exposure to noise levels exceeding 80 dB may lead to a higher prevalence of hypertension and to increased blood pressure values, although the results appear quantitatively different according to the approach that is taken to the problem (i.e. the epidemiologic or the case versus control approach).

Effect of a westward transmeridian flight on ambulatory blood pressure monitoring in normotensive subjects.

OBJECTIVE: To evaluate the effects of a westward transmeridian flight over six time zones (from Milan to New York) on ambulatory blood pressure monitoring (ABPM) in normotensive individuals. METHODS: Eighteen normotensive subjects (blood pressure < 140/90 mmHg), 11 men and seven women, of mean age 38.3 years, were studied. On the day of travel they underwent 26 h noninvasive ABPM (started at 1100 h); the take-off time was 1200 h and the landing time was 8 h later, at 1400 h New York time (2000 h Italian time). Subjects were requested not to sleep until 2300 h and to get up at 0700 h the following morning. The results were compared with those of a 26 h ABPM performed in Italy the week before during which they slept from 2300 h to 0700 h. RESULTS: During the flight blood pressure and heart rate did not change compared with values during the corresponding time interval of the control day. After the landing, during the New York afternoon and evening (corresponding to the Italian sleeping time), blood pressure and heart rate remained unchanged, whereas during the night they decreased significantly, although their drop was less pronounced than that during the control day. CONCLUSION: The results of this study indicate that the decrease in blood pressure during sleep is the result of sleep itself rather than of the actual time of day.

Effects of different dihydropyridine calcium antagonists on plasma norepinephrine in essential hypertension.

OBJECTIVE: The aim of this study was to compare the chronic effects of four dihydropyridine calcium antagonists with different pharmacologic characteristics, amlodipine, felodipine, lacidipine and manidipine,on blood pressure (BP), heart rate (HR) and plasma norepinephrine (NE) levels in patients with mild to moderate essential hypertension. METHOD: After a 4-week placebo period, 60 patients of both sexes were randomly administered amlodipine 5-10 mg once daily (o.d.) (n = 15); felodipine 5-10 mg o.d. (n = 15); lacidipine 4-6 mg o.d. (n = 15); manidipine 10-20 mg o.d. (n = 15), for 24 weeks, according to a double blind, parallel group design. Initially, for the first 2 weeks, the lowest dose of each drug was used, then higher doses were administered if sitting diastolic blood pressure (DBP) was > 90 mmHg. BP, HR and plasma NE were evaluated at the end of the placebo and active treatment periods. NE was assessed at trough, at peak and after 12 h from drug ingestion. RESULTS: Administration of all four drugs reduced clinic BP to the same level after 24 weeks, whereas HR increased only with felodipine (+ 3.1 bpm; P< 0.05). Significant increases in plasma NE levels were observed after chronic therapy with amlodipine and felodipine (+ 34.9 and + 39.4% respectively; P< 0.01 versus placebo) but not with lacidipine (+ 7.1%, NS) and manidipine (+ 2.9%, NS). CONCLUSIONS: These findings suggest that sympathetic activation occurred during chronic treatment with amlodipine and felodipine, whereas manidipine and lacidipine did not increase plasma noradrenaline at the times measured. The reasons for this difference are unclear; they could be related to the different pharmacological characteristic of the two drugs, lacidipine and manidipine.

Transient but not sustained blood pressure increments by occupational noise. An ambulatory blood pressure measurement study.

OBJECTIVE: Studies on the effects of chronic exposure to industrial noise on clinic blood pressure (BP) at rest have yielded inconsistent results. The aim of this study was to evaluate the effect of occupational noise exposure on ambulatory blood pressure (ABP) in normotensive subjects. METHODS: We studied 476 normotensive workers, aged 20-50 years (systolic blood pressure (SBP) < 140, diastolic blood pressure (DBP) < 90), at a metallurgical factory; 238 were exposed to high levels of noise (> 85 dB), while 238 were not exposed (< 80 dB). Clinical evaluation included measurements of casual BP (by standard mercury sphygmomanometer, Korotkoff sound phase I and V) and heart rate (HR) (by pulse palpation), body height and weight. All subjects underwent a 24 h non-invasive ABP monitoring (by SpaceLabs 90207 recorder; SpaceLabs, Redmond, Washington, USA) twice within 14 days: one during a normal working day and one during a non-working day. Measurements were performed every 15 min. Computed analysis of individual recordings provided average SBP, DBP and HR values for 24 h, daytime working hours (0800-1700 h), daytime non-working hours (1700-2300 h) and night-time (2300-0800 h). RESULTS: No significant difference in clinic SBP, DBP and HR was observed between exposed and non-exposed subjects. Results obtained by ABP monitoring showed in the exposed workers: (a) a higher SBP (by a mean of 6 mmHg, P < 0.0001 versus controls) and DBP (by a mean of 3 mmHg, P < 0.0001) during the time of exposure and the following 2 or 3 h, whereas no difference between the two groups was found during the non-working day; (b) an increase in HR, which was present not only during the time of exposure to noise (+3.7 beats-per-minute (bpm), P < 0.0001 versus controls), but also during the non-working hours (+2.8 bpm, P < 0.001) and during the day-time hours of the non-working day (+2.8 bpm, P < 0.003); (c) a significant increase in BP variability throughout the working day. CONCLUSIONS: These findings suggest that in normotensive subjects below the age of 50 years, chronic exposure to occupational noise is associated with a transient increase in BP, which is not reflected in a sustained BP elevation. The possible role of repeated BP and HR fluctuations due to frequent and prolonged exposure to noise in accounting for the higher prevalence of hypertension reported in noise-exposed workers above age 50 years, requires longitudinal studies to be clarified.

In vivo evaluation of a new polyurethane-coated catgut suture.

Plain catgut sutures were coated with different polyester-based polyurethanes. The sutures were implanted subcutaneously in rats and tested for tensile strength loss and tissue reactions. A polyurethane coating based on an oxalic acid polyester was hydrolysed too fast to protect the catgut against proteolysis. However, a 2-0 plain catgut having a 50 micron polyurethane coating based on glutaric acid polyester maintained its original tensile strength for 8 days. The tensile strength then decreased as for plain catgut. Histological examination of the surrounding tissues showed that the strong inflammatory reaction observed in the first three days with non-coated catguts is decreased, but occurs again later, although to a lesser extent.

Heart and hypertension.

The manifestations of cardiac involvement in hypertension include: (1) the development of hypertensive heart disease characterized by left ventricular hypertrophy (LVH), and (2) the consequences of coronary atherosclerosis, as angina pectoris, myocardial infarction, and sudden cardiac death. Whereas the former is directly related to increased blood pressure, the latter are sequelae of atherosclerosis per se, and hypertension acts only as a risk factor in this regard. This can partially explain why antihypertensive treatment is effective in diminishing the incidence of congestive heart failure, which is the final consequence of LVH, but is not very effective in preventing coronary complications. It is generally accepted about LVH that increased arterial pressure is the major stimulus to cardiac hypertrophy in hypertension; however, there are a lot of both quantitative and qualitative events suggesting that other factors beside blood pressure levels can modulate the development of LVH, in particular neurohumoral influences. From a morphological point of view, hypertrophy of the cardiac muscle is defined as an increase in the size of existing myocardial fibers. In most experimental models, myocardial hypertrophy is associated with myosin isoenzymatic changes, consisting in a shift from the faster migrating isoenzyme V1 to V3, a form that migrates more slowly. However these changes do not occur in all animal species and particularly in humans. In the hypertrophied human ventricle, a decreased ATPase activity of myofibrils was observed, probably related to changes in myosin light chains. Presently the changes in ATPase activity and in ventricular contractility do not still have a clear molecular basis in humans.(ABSTRACT TRUNCATED AT 250 WORDS)

Urinary albumin excretion and nocturnal blood pressure in hypertensive patients with type II diabetes mellitus.

The aim of this study was to evaluate the relationship between nocturnal blood pressure (BP) (by ambulatory blood pressure monitoring, ABPM) and urinary albumin excretion (UAE) in hypertensive patients with type II diabetes mellitus. We studied 179 essential hypertensives (WHO I-II), all males, with non-insulin-dependent diabetes. Non-invasive ABPM was performed by a fully automatic, portable device (Spacelabs 90202), set to take readings at 15-min intervals during both day-time 7 AM to 1 PM and nighttime (1 PM to 7 AM). According to the day/night reduction in mean blood pressure (MBP), three groups were identified: group I, nocturnal MBP reduction > 10%; group II, day/night MBP reduction of 5% to 10%; and group III, day/night MBP reduction < 5%. The mean values of UAE as well as the prevalence of microalbuminuria (UAE > 30 mg/24 h) were found to be significantly higher in group III as compared to the other two groups. Besides, in group III UAE displayed a significant negative relationship with the SBP and MBP (but not DBP) nocturnal drop and a positive relationship with the duration of hypertension and duration of diabetes. In group II, UAE was weakly correlated only with the duration of hypertension, whereas in group I no significant correlation was found between UAE and other parameters of the study. These results indicate that in hypertensive type II diabetic patients a blunted nocturnal BP fall is associated with higher UAE and increased prevalence of microalbuminuria. Whether the reduced day/night BP difference is the cause of consequence of target organ damage remains to be established.

Ambulatory blood pressure monitoring in normotensive and hypertensive type 2 diabetes. Prevalence of impaired diurnal blood pressure patterns.

To assess the prevalence of an impaired diurnal blood pressure (BP) pattern in a population of both normotensive and hypertensive diabetics, noninvasive ambulatory BP monitoring (SpaceLabs 5200, Redmond, WA) was performed in 96 outpatients with type 2 diabetes (47 normotensives and 48 hypertensives) and in 103 control subjects without diabetes (50 normotensives and 53 hypertensives). Mean 24 h and daytime (06:00 to 22:00) BP and heart rate (HR) were not statistically different in diabetic patients compared to nondiabetic ones. Nighttime (22:00 to 06:00) BP and HR tended to be higher in both normotensive and hypertensive diabetics, although not significantly. Heart rate, diastolic BP (DBP), and especially the nocturnal systolic BP (SBP) decrease, were less marked in both normotensive and hypertensive diabetics, with a consequent increase in rate-pressure. A significant correlation was found between the percent decrease in nighttime SBP and the decrease in orthostatic SBP in casual BP measurements. The analysis of individual recordings allowed us to detect an impaired circadian pattern (the disappearance of the nocturnal BP decrease or a paradoxical BP increase) in 30% of the normotensive and 31% of the hypertensive diabetics (v 6% of the normotensive and 6.4% of the hypertensive nondiabetic subjects). As the absence of a nocturnal BP fall has been associated with the increased prevalence of left ventricular hypertrophy and atherosclerotic cardiovascular disease, its detection by ambulatory monitoring might be of prognostic and therapeutic importance.

Sexual function in hypertensive males treated with lisinopril or atenolol: a cross-over study.

To evaluate the effect of antihypertensive treatment on sexual activity, 90 hypertensive men, aged 40 to 49 years, all married and without history of sexual dysfunction were treated with 100 mg of atenolol or 20 mg of lisinopril for 16 weeks, according to a double-blind, randomized, cross-over design. During the first month of therapy, sexual activity, assessed as number of sexual intercourse episodes per month, significantly declined with both atenolol (from 7.8 +/- 4.3 to 4.5 +/- 2.8, P < .01 v placebo) and lisinopril (from 7.1 +/- 4.0 to 5.0 +/- 2.5, P < .05 v placebo). Ongoing with the treatment, sexual activity tended toward recovery in the lisinopril (7.7 +/- 4.0 sexual intercourse episodes per month, P = NS v placebo), but not in the atenolol group (4.2 +/- 2.8, P < .01 v placebo), with a statistically significant difference between the two drugs (P < .01). The percentage of patients who complained of sexual dysfunction symptoms was significantly higher in the atenolol- than in the lisinopril-treated group (17% v 3%, P < .05). These findings suggest that atenolol induces a chronic worsening of sexual activity, whereas lisinopril causes only a temporary decline.