Study on the structure and properties of wool keratin regenerated from formic acid.

Structural characteristics of keratin regenerated from water (KW) and from formic (KF) acid solutions were compared. Amino acid composition and molecular weight distribution of KW and KF samples were studied by high performance liquid chromatography (HPLC) and SDS-PAGE electrophoresis. Turbidity measurement showed that keratin dissolved in formic acid forms transparent and stable solutions and no flocculation occurs. In addition, because of its good solvation properties, studied by viscosity measurements, formic acid can be used as a co-solvent to prepare keratin-based blend solutions. Structural studies carried out by X-ray diffraction (XRD), Fourier transform infrared (FT-IR) and near infrared (NIR) suggest that formic acid stabilizes the beta-sheet structure. Thermogravimetric analysis (TGA) reveals a higher thermal stability of keratin regenerated from formic acid with respect to keratin regenerated from water.

[Out-of-hospital resuscitation in Israel 2000].

The aim of the study was to evaluate the impact of pre-hospital cardio-pulmonary resuscitation, performed by mobile intensive cardiac care units of Magen David Adom (MDA) teams in the framework of a national survey conducted in the period February and March 2000. During the survey, MDA performed 539 resuscitations, 485 of which were performed by mobile intensive care units of MDA, and they constitute the study population of the present analysis. The average age of the patients was 70.5 years, and 68% were men. The mean response time of the mobile intensive care units was 10.3 minutes. In 14% of the cases, a bystander initiated basic cardiac life support before the arrival of the MDA team. Upon arrival of the resuscitation team, 242 patients (50%) had asystole, 19% ventricular tachycardia (VT)/ventricular fibrillation (VF), 13% pulseless electrical activity (PEA), and 18% had other severe arrhythmias. One hundred and ninety-nine patients (41%) were transferred alive to the hospital after successful resuscitation. Hospital summaries were obtained for 148 of these patients. The cause of cardiac arrest was cardiac in 64% of the cases and 48% of the patients who reached the hospital had a previous history of heart disease. Fifty-three patients (11%) were discharged alive from the hospital. Patients discharged alive were younger, more promptly resuscitated, 78% had a cardiac cause of death and 38% of them were in ventricular tachycardia/fibrillation when first seen by the resuscitation team. The rate of successful resuscitation to discharge in the sub-group with VT/VF was 21%, and only 4% for patients in asystole, which is in line with other studies. However, the rate of initiation of resuscitation by bystanders is low in Israel. These data may help the medical staff and the health policy providers in Israel.

The effect of valvular heart disease on maternal and fetal outcome of pregnancy.

OBJECTIVES: The aim of this study was to evaluate the association between valvular heart disease (VHD) and maternal and fetal outcome in a relatively large group of patients by a comparison to a well-matched control group. BACKGROUND: Available information regarding outcome of pregnancy in women with VHD is limited to either anecdotal reports or small series of patients without an appropriate control. A better understanding of the effects of valvular abnormalities on pregnancy outcome is of value for risk assessment and the design of a therapeutic plan. METHODS: A retrospective evaluation was made of 66 pregnancies in 64 women with VHD cared for at a tertian-care center with a high-risk obstetrics/cardiology clinic and 66 individually selected normal pregnant women matched in age, ethnicity, obstetrical and medical history, time of initial prenatal care, and year of pregnancy. RESULTS: Women with VHD had a significantly higher incidence of congestive heart failure (38% vs. 0%; p < 0.00001), arrhvthmias (15% vs. 0%, p = 0.002), initiation or increase of cardiac medications (41% vs. 2%, p < 0.0001), and hospitalizations (35% vs. 2%, p < 0.0001). Mortality, however, occurred in only one patient (2% vs. 0%, p = NS) with aortic stenosis (AS) and coarctation. Moreover, VHD also had an effect on fetal outcome, resulting in an increased preterm delivery (23% vs. 6%, p = 0.03), intrauterine growth retardation (21% vs. 0%, p < 0.0001), and a reduced birth weight (2,897 +/- 838 g vs. 3,366 +/- 515 g, p = 0.0003). Increased maternal morbidity and unfavorable fetal outcome were seen mostly in patients with moderate and severe mitral stenosis (MS) and AS. CONCLUSIONS: Pregnancy in women with MS and AS is associated with marked increase in maternal morbidity and unfavorable effect on fetal outcome, which are related to severity of disease. Despite high maternal morbidity, mortality is rare.

Double-blind, placebo-controlled study to evaluate the effect of organic nitrates in patients with chronic heart failure treated with angiotensin-converting enzyme inhibition.

BACKGROUND: Organic nitrates are widely used in the treatment of chronic heart failure (CHF). No information, however, is available regarding their effect in patients already treated with ACE inhibitors. METHODS AND RESULTS: In a randomized, double-blind, crossover design, we studied the effects of high-dose (50 to 100 mg) transdermal nitroglycerin (NTG) and placebo given daily for 12 hours in 29 patients with CHF (NYHA functional classes II to III). Exercise time (4 hours after patch application) showed a progressive improvement during NTG administration, with an increase of 38+/-35 seconds (9+/-7%) at the end of the first month (P=NS), 76+/-28 seconds (16+/-6%) at the end of the second month (P=0.01), and 117+/-34 seconds (27+/-6%) at the end of the third month (P=0.003). No significant change was seen during placebo administration (12+/-20, 5+/-26, and 19+/-28 seconds, all P=NS). Exercise time 8 hours after NTG application measured at 3 months was also significantly longer, with a difference of 87+/-28 seconds (P=0.006), but not with placebo (23+/-36 seconds, P=0.53). Assessment of quality of life and need for additional diuretics or hospitalizations for CHF failed to demonstrate a significant difference between the 2 treatment periods. In contrast, NTG decreased left ventricular end-diastolic (-2.1+/-0.1%, P<0.05) and end-systolic (-3.2+/-1.3%, P<0.05) dimensions and augmented LV fractional shortening (24.7+/-10.5%, P<0.03). The effect of placebo on these parameters was not statistically significant. CONCLUSION: High-dose nitrate therapy significantly improves exercise tolerance and left ventricular size and systolic function in patients with chronic, mild to moderate CHF already treated with ACE inhibitors. These findings support the role of organic nitrates as an adjunctive therapy to ACE inhibitors in patients with chronic CHF.

Renal circulatory effects of adenosine in patients with chronic heart failure.

OBJECTIVES: We sought to study the renal circulatory effects of adenosine in patients with chronic congestive heart failure (CHF). BACKGROUND: Renal blood flow (RBF) is often reduced in patients with chronic CHF and may lead to decreased renal function. The cause of reduced RBF is multifactorial and involves systemic as well as local vasoregulatory mechanisms. Stimulation of renal adenosine A1 receptors in animal models has resulted in a significant vasoconstriction of afferent and efferent glomerular arterioles and deterioration of renal function. Although adenosine serum levels have been shown to be elevated in patients with CHF, their effect on the renal circulation in this patient population has not been studied. METHODS: Nine patients with CHF from left ventricular systolic dysfunction were studied. The effects of adenosine at a dose of 10(-5) mol/liter infused directly into the main renal artery on heart rate, renal artery blood pressure, renal artery cross-sectional area (measured by intravascular ultrasound), renal Doppler blood flow velocity (measured by a Doppler flow wire in the renal artery), RBF and renal vascular resistance (RVR) were evaluated. RESULTS: Infusion of adenosine resulted in no significant effect on heart rate or renal artery blood pressure but caused a substantial increase in RVR (11,204 +/- 1,469 to 31,494 +/- 3,911 dynes x s x cm(-5), p = 0.0005), which led to a marked fall in RBF in every patient (mean values 376 +/- 36 to 146 +/- 22 ml/m2, p = 0.0002). These changes in RVR and RBF were associated with no significant change in renal artery cross-sectional area (0.389 +/- 0.040 to 0.375 +/- 0.033 cm2, p = 0.3). CONCLUSIONS: Stimulation of renal adenosine receptors in patients with CHF results in marked renal vasoconstriction that leads to an important reduction in RBF. Lack of change in renal artery cross-sectional area suggests that adenosine affects intrarenal resistance blood vessels rather than large conductance vessels. These results may indicate a rationale for investigation of renal adenosine receptor blockade for enhancement of RBF and improvement of renal function in patients with chronic CHF.

Significance of paroxysmal atrial fibrillation complicating acute myocardial infarction in the thrombolytic era. SPRINT and Thrombolytic Survey Groups.

BACKGROUND: Paroxysmal atrial fibrillation (PAF) is considered a frequent complication of acute myocardial infarction (AMI), associated with increased in-hospital and long-term mortality rates. This notion is based on data collected before thrombolysis and additional modern methods of treatment became widely available, and no information is available on the significance of PAF in the general population with AMI in the thrombolytic era. The aim of the present study was to define the incidence, associated clinical parameters, and short- and long-term prognostic significance of PAF in patients with AMI in the thrombolytic era. METHODS AND RESULTS: A prospective, nationwide survey was conducted of 2866 consecutive patients admitted with AMI in all 25 coronary care units in Israel during January/February 1992, 1994, and 1996 (thrombolytic era [TE]). The data were compared with a previous Israeli study of 5803 patients with AMI hospitalized in 1981 through 1983 (prethrombolytic era [PTE]). Patients in the TE with PAF were older and had a worse risk profile than those without PAF. PAF in the TE was independently associated with increased 30-day (odds ratio, 1.32; 95% confidence interval, 0.92 to 1.87) and 1-year (relative risk, 1.33; 95% confidence interval, 1.05 to 1.68) mortality rates. The incidence of PAF (8.9% and 9.9%) and the 30-day (25.1% and 27.6%) and 1-year (38.4% and 42.5%) mortality rates of patients with PAF were similar in the TE and PTE, although PAF in the TE occurred in older and sicker patients than those in the PTE. After adjustment for conventional risk factors, PAF was associated with significantly lower 30-day (odds ratio, 0.64; 95% confidence interval, 0.44 to 0.94) and 1-year (relative risk, 0.69; 95% confidence interval, 0.54 to 0.88) mortality rates compared with the PTE. CONCLUSIONS: Patients with AMI who develop PAF in the TE have significantly worse short- and long-term prognoses than patients without PAF, mostly due to their worse risk profile. After adjustment for confounding factors, patients with PAF in the TE have a better overall outcome than counterparts in the PTE, probably reflecting the better management of patients with AMI in the TE.

A two-year study on the efficacy and tolerability of policosanol in patients with type II hyperlipoproteinaemia.

This is a report of the results of a two years' randomized, double-blind placebo-controlled study of the efficacy, safety, and tolerability of policosanol administered at 5 mg twice-a-day in the treatment of type II hyperlipoproteinaemia. The study included 69 patients from both sexes, in whom total cholesterol and low-density-lipoprotein cholesterol (LDL-C) were not controlled sufficiently by diet. The treatment effect on total cholesterol and LDL-C was maintained during the 2-year follow up. Thus, percent reductions 24 months after therapy were 25% (LDL-C) and 18% (cholesterol). All comparisons with placebo were significant. Similarly, ratios of LDL-C to HDL-C and cholesterol to HDL-C were significantly reduced and such decreases were maintained during the study. Policosanol raised significantly the values of high-density lipoprotein cholesterol (HDL-C) during the study and maximal increases were reached 12 months after therapy (+21%). From this time the increases mildly declined to +14% and +11.2% respectively at 18 and 24 months after therapy. No significant changes in triglycerides were observed as compared with baseline or placebo. No patient withdrew from the study because of adverse effects. No drug-related clinical or biochemical adverse side-effects were observed. Any adverse experiences reported were mild and transient; moreover, no significant differences were obtained when compared with those reported by the placebo group. The results indicate that policosanol administered for two years to patients with type II hypercholesterolaemia shows a maintained efficacy as well as very good safety and tolerability.

Mitral mechanical valve without long-term anticoagulation. Eight-year follow-up.

In 12 patients with sinus rhythm (including 5 children and 6 young women), mitral valve replacement was performed with a microporous-surfaced valve similar to the Björk-Shiley Monostrut. After the first 3 months, permitting endothelialization of the suture ring to continue over the groove and adjacent metal valve ring, no long-term anticoagulant treatment was given. There was no thromboembolic complication in this group during follow-up for 6-8 years, during which four women gave birth to a total of seven children. In eight other cases, one mitral case with atrial fibrillation, anti-coagulant was not discontinued, and in the remaining aortic cases it was reinstituted. One of them (with atrial fibrillation) had hematuria during inadequate anticoagulant medication, but no thromboembolism. Of five patients with only aortic valve replacement, two had thromboembolic complications, one without residual symptoms and one with slight hand weakness. Another had a transient ischemic attack while on anticoagulant and acetylsalicylic acid was added. Two patients with aortic and mitral valve replacement died, one from heart tamponade and the other from venous thrombosis with pulmonary embolism.

Divergent age-associated patterns of high density lipoprotein cholesterol and its percentage in Jewish and Moslem Arab Israeli children and adolescents: the Petach Tikva Project.

We studied three groups of Israeli Jewish schoolchildren in and surrounding Petach Tikva, Israel, cross-sectionally, at ages 9-10, 13-14, and 16-18 years, and compared lipid and lipoprotein levels and age-associated lipoprotein patterns in the same age groups of boys and girls in neighboring Israeli Moslem Arab schools during 1986-1987. Moslem children displayed striking differences in the levels of lipids and age-associated patterns of lipoproteins compared with Jewish schoolchildren. The mean total cholesterol levels were lower in the Moslem children, in both sexes, in every age grouping. High density lipoprotein cholesterol (HDL-C) levels were significantly higher at age 16-18 in the Moslem boys than in the Jewish boys. While the Jewish boys displayed a previously reported "typical" pattern of lower HDL-C levels postpuberty compared with prepuberty, the Moslem boys had markedly higher mean HDL-C levels at age 16-18 compared with those at age 9-10. The Moslem girls also had higher HDL-C levels at age 16-18 than those observed in the age 9-10 group. Concomitantly higher HDL-C levels (HDL-C/total cholesterol (%)) were seen in the Moslem boys and girls, at age 16-18 compared with age 9-10, but were not observed in the Jewish children. The identification of an ethnic group in whom HDL-C appears to increase at or near puberty could provide opportunities to elucidate factors that may increase HDL-C in individuals or in populations.

The effect of serum from patients with acute myocardial infarction on in vitro lymphocyte reactivity. II. Inhibition of IL-2 production.

Culture supernatants from concanavalin-A (con-A)-activated peripheral blood lymphocytes from healthy controls grown in the presence of sera from 20 patients 24 hours and 1 week after acute myocardial infarction (AMI) were tested for their mitogenic activity and for the presence of interleukin-2 (IL-2). Binding of exogenous IL-2 to activated lymphocytes from 10 patients was also determined. In supernatants prepared in the presence of patients' as compared to control sera, a significantly decreased mitogenic activity and IL-2 content were found. The mitogenic activity and IL-2 content in culture supernatants prepared with patients' sera collected 24 hours after the AMI (AMI I) and one week thereafter (AMI II) were significantly suppressed, and the degree of suppression in the 24-hour sera was significantly higher than in those collected after one week. No significant differences were observed in the binding capacity to exogenous IL-2 of activated patients' and control lymphocytes. The possibility is that immunosuppressive factors in the patients' sera, including cortisol, may suppress the patients' immune response acting through inhibition of IL-2 production.

The effect of serum from patients with acute myocardial infarction on in vitro lymphocyte reactivity. I. Inhibition of mitogen stimulation.

Sera from 20 patients obtained within 24 hours and one week after acute myocardial infarction (AMI) were tested for their immunomodulating effect on concanavalin-A (con-A) stimulated lymphocyte cultures from 11 healthy unrelated donors. Individual control sera from 21 healthy donors and 5 pools of control sera were used for comparison. Cortisol levels were tested in patients' and controls' sera. A significantly higher suppressive effect was seen in the presence of patients' sera taken at 24 hours than corresponding sera taken one week later. However, the suppressive effect after one week was increased as compared to control sera. A significant correlation between the degree of suppression and the cortisol level in corresponding sera was observed. An increased immunosuppression was observed with increased cortisol levels.

CD and small-angle x-ray scattering of silk fibroin in solution.

We investigated the structure of silk fibroin dissolved in water and in water-organic solvent mixtures by CD and small-angle x-ray scattering (SAXS). CD spectra indicated a disordered secondary structure in water and a beta-sheet conformation in aqueous organic solvents, such as methanol, dioxane, and trifluoroethanol (in trifluoroethanol a transient form evolving toward beta-sheet conformation was seen just after dissolution). The SAXS technique indicated the presence of fibroin particles of lamellar shape. The molecular weight was 188,000 daltons in water and 302,000 daltons in aqueous methanol.