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L Dornfeld

Publications and source records attributed to L Dornfeld.

At least 19 recordsLinked to original sources
PubMed2002

Pomegranate juice flavonoids inhibit low-density lipoprotein oxidation and cardiovascular diseases: studies in atherosclerotic mice and in humans.

The beneficial health effects attributed to the consumption of fruit and vegetables are related, at least in part, to their antioxidant activity. Of special interest is the inverse relationship between the intake of dietary nutrients rich in polyphenols and cardiovascular diseases. This effect is attributed to polyphenols' ability to inhibit low-density lipoprotein (LDL) oxidation, macrophage foam cell formation and atherosclerosis. Pomegranate polyphenols can protect LDL against cell-mediated oxidation via two pathways, including either direct interaction of the polyphenols with the lipoprotein and/or an indirect effect through accumulation of polyphenols in arterial macrophages. Pomegranate polyphenols were shown to reduce the capacity of macrophages to oxidatively modify LDL, due to their interaction with LDL to inhibit its oxidation by scavenging reactive oxygen species and reactive nitrogen species and also due to accumulation of polyphenols in arterial macrophages; hence, the inhibition of macrophage lipid peroxidation and the formation of lipid peroxide-rich macrophages. Furthermore, pomegranate polyphenols increase serum paraoxonase activity, resulting in the hydrolysis of lipid peroxides in oxidized lipoproteins and in atherosclerotic lesions. These antioxidative and antiatherogenic effects of pomegranate polyphenols were demonstrated in vitro, as well as in vivo in humans and in atherosclerotic apolipoprotein E deficient mice. Dietary supplementation of polyphenol-rich pomegranate juice to atherosclerotic mice significantly inhibited the development of atherosclerotic lesions and this may be attributed to the protection of LDL against oxidation.

Animals↗
PubMed2001

Pomegranate juice consumption inhibits serum angiotensin converting enzyme activity and reduces systolic blood pressure.

Consumption of pomegranate juice which is rich in tannins, possess anti-atherosclerotic properties which could be related to its potent anti-oxidative characteristics. As some antioxidants were recently shown to reduce blood pressure, we studied the effect of pomegranate juice consumption (50 ml, 1.5mmol of total polyphenols per day, for 2 weeks) by hypertensive patients on their blood pressure and on serum angiotensin converting enzyme (ACE) activity. A 36% decrement in serum ACE activity and a 5% reduction in systolic blood pressure were noted. Similar dose-dependent inhibitory effect (31%) of pomegranate juice on serum ACE activity was observed also in vitro. As reduction in serum ACE activity, even with no decrement in blood pressure, was previously shown to attenuate atherosclerosis, pomegranate juice can offer a wide protection against cardiovascular diseases which could be related to its inhibitory effect on oxidative stress and on serum ACE activity.

Aged↗
PubMed2001

Pomegranate juice supplementation to atherosclerotic mice reduces macrophage lipid peroxidation, cellular cholesterol accumulation and development of atherosclerosis.

Inhibition of lipid peroxidation contributes to the attenuation of macrophage cholesterol accumulation, foam-cell formation and atherosclerosis. Evidence suggests that nutritional antioxidants such as pomegranate juice (PJ) can contribute to the reduction of oxidative stress and atherogenesis. The goals of the present study were to determine whether such beneficial effects of PJ exist when supplemented to apolipoprotein E-deficient (E(0)) mice with advanced atherosclerosis and to analyze the antiatherosclerotic activity of a tannin-fraction isolated from PJ. Mice (4-mo-old) were supplemented with PJ in their drinking water for 2 mo and compared with age-matched placebo-treated mice, as well as to young (4-mo-old) control mice, for their mouse peritoneal macrophage (MPM) oxidative state, cholesterol flux and mice atherosclerotic lesion size. PJ supplementation reduced each of the proatherogenic variables determined in the present study compared with age-matched placebo-treated mice. It significantly induced serum paraoxonase activity and reduced MPM lipid peroxide content compared with placebo-treated mice and control mice. PJ administration to E(0) mice significantly reduced the oxidized (Ox)-LDL MPM uptake by 31% and MPM cholesterol esterification and increased macrophage cholesterol efflux by 39% compared with age-matched, placebo-treated mice. PJ consumption reduced macrophage Ox-LDL uptake and cholesterol esterification to levels lower than those in 4-mo-old, unsupplemented controls. PJ supplementation to E(0) mice with advanced atherosclerosis reduced the lesion size by 17% compared with placebo-treated mice. In a separate study, supplementation of young (2-mo-old) E(0) mice for 2 mo with a tannin fraction isolated from PJ reduced their atherosclerotic lesion size, paralleled by reduced plasma lipid peroxidation and decreased Ox-LDL MPM uptake. PJ supplementation to mice with advanced atherosclerosis reduced their macrophage oxidative stress, their macrophage cholesterol flux and even attenuated the development of atherosclerosis. Moreover, a tannin-fraction isolated from PJ had a significant antiatherosclerotic activity.

Animals↗
PubMed2000

Pomegranate juice consumption reduces oxidative stress, atherogenic modifications to LDL, and platelet aggregation: studies in humans and in atherosclerotic apolipoprotein E-deficient mice.

BACKGROUND: Dietary supplementation with nutrients rich in antioxidants is associated with inhibition of atherogenic modifications to LDL, macrophage foam cell formation, and atherosclerosis. Pomegranates are a source of polyphenols and other antioxidants. OBJECTIVE: We analyzed, in healthy male volunteers and in atherosclerotic apolipoprotein E-deficient (E(0)) mice, the effect of pomegranate juice consumption on lipoprotein oxidation, aggregation, and retention; macrophage atherogenicity; platelet aggregation; and atherosclerosis. DESIGN: Potent antioxidative effects of pomegranate juice against lipid peroxidation in whole plasma and in isolated lipoproteins (HDL and LDL) were assessed in humans and in E(0) mice after pomegranate juice consumption for </=2 and 14 wk, respectively. RESULTS: In humans, pomegranate juice consumption decreased LDL susceptibility to aggregation and retention and increased the activity of serum paraoxonase (an HDL-associated esterase that can protect against lipid peroxidation) by 20%. In E(0) mice, oxidation of LDL by peritoneal macrophages was reduced by up to 90% after pomegranate juice consumption and this effect was associated with reduced cellular lipid peroxidation and superoxide release. The uptake of oxidized LDL and native LDL by mouse peritoneal macrophages obtained after pomegranate juice administration was reduced by 20%. Finally, pomegranate juice supplementation of E(0) mice reduced the size of their atherosclerotic lesions by 44% and also the number of foam cells compared with control E(0) mice supplemented with water. CONCLUSION: Pomegranate juice had potent antiatherogenic effects in healthy humans and in atherosclerotic mice that may be attributable to its antioxidative properties.

Adult↗
PubMed1985

Defective renal prostaglandin synthesis in hypertensive patients with morbid obesity.

Renal prostaglandin synthesis in 36 obese hypertensive patients was estimated from measurements of 24-hour urinary prostaglandin E2 (PGE2) excretion rates. PGE2 was measured by radioimmunoassay using Dray antiserum prior to and 1 week after starting a fast supplemented by 320 cal derived from 30 g of carbohydrate, 45 g protein, and 2 g essential fatty acids. Sodium intake was 120 mEq daily or less. Comparisons were made to a control population of age-matched, nonobese, normotensive, healthy volunteers on a normal diet. Mean weight fell from 260 +/- 8 to 247 +/- 8lb, p less than 0.001. Urinary PGE2 in the obese patients prior to the fast was 104 +/- 27 ng/day, significantly lower than the 404 +/- 124 ng/day found in the control population, p less than 0.005. After the 1st week of the fast urinary PGE2 rose to 213 +/- 55, p less than 0,02. This value was not different from that in the control group. Blood pressure fell (p less than 0.001) in these patients from 143/94 +/- 3/2 to 134/87 +/- 3/2 mm Hg after the 1st week of the fast. Deficient renal prostaglandin synthesis in obese hypertensive patients was corrected by fasting. Such changes in the prostaglandin system may mediate or occur in response to changes in the sodium-volume balance of these patients. These changes in renal prostaglandin synthesis may partly contribute to the blood pressure reduction of these patients.

Blood Pressure↗
PubMed1983

Effects of weight loss on the dexamethasone suppression test.

The authors studied postdexamethasone cortisol secretion in 18 depression-free, healthy, obese subjects before and after weight loss. Although all subjects suppressed cortisol normally before weight loss, 5 of 18 (27.5%) failed to suppress cortisol after an average loss of 13.5 kg. This failure to suppress cortisol was not associated with any change in depression ratings.

Body Weight↗
PubMed1983

A comprehensive psychological approach to obesity.

Many different treatments for obesity have proven somewhat successful, with none emerging as clearly superior to the others. Surgical approaches, although usually successful at achieving and maintaining weight loss, are accompanied by varied and often harmful side effects. Unless new, safer procedures are developed, treatment may continue to be as hazardous as the obesity itself. Because medical treatment alone has not achieved beneficial, lasting results, research aimed at finding new procedures should be encouraged. Our five-year experience in working with obese patients has led us to the following conclusions: 1. The management of obesity must be a joint venture between psychiatry and medicine. Because of the complex nature of this illness, neither discipline alone can successfully and safely achieve significant initial weight loss coupled with successful long-term maintenance. The use of adjunctive psychological programs in a medical setting can be a successful alternative. 2. Fasting, weight loss, and realimentation must be accompanied by an effort at lifestyle change. Otherwise, patients will continue their self-destructive habits, which will ultimately lead to failure in yet another attempt at sustained weight reduction. The behavioral approach has provided a fairly effective treatment of obesity, sometimes with immediate results. Recent studies support the maintenance effect of behavioral treatments. However, longer studies with follow-ups are needed to better assess the overall effectiveness of these treatments. 3. Despite much false optimism that weight loss is a simple road to happiness, most patients experience some very real problems during the fasting part of the program. Crisis intervention can prove very helpful in terms of reducing stress and preventing dropouts. Group therapy, individual therapy, family therapy, and hypnosis have attained some very limited positive results when used alone; greater success has been reported from combining therapies. Patients generally became more socially effective, physically active, and mentally proficient when exposed to individual therapy together with group and family therapies. 4. Family environment appears to significantly affect compliance and completion. A conflict-laden family environment hampers the patient's ability to deal with the psychological changes encountered in weight loss programs. 5. Many obese patients lack a fundamental knowledge of nutrition, exercise, and health. In addition, most are poorly socialized and require assistance in learning assertiveness and other interpersonal skills. A behaviorally oriented component is very effective in providing these skills.(ABSTRACT TRUNCATED AT 400 WORDS)

Adult↗
PubMed1982

Role of the sympathetic nervous system in blood pressure maintenance in obesity.

A group of 10 borderline hypertensive obese subjects had higher (P less than 0.05) supine plasma norepinephrine (NE), epinephrine, and PRA levels as well as greater (P less than 0.05) NE responses to upright posture and isometric handgrip exercise than 12 nonobese controls. Plasma NE as well as mean arterial pressure (MAP) responses to posture and handgrip in the obese patients demonstrated a significant decrement at week 2 after the onset of a low calorie diet. Decrements in plasma NE and MAP responses to posture were correlated (r = 0.61; P less than 0.05) throughout an 8-week period of weight loss in these borderline hypertensive obese subjects. In 15 normotensive obese subjects as well as in the 10 borderline hypertensive obese subjects, weight reduction associated with a very low calorie intake was accompanied by a reduction in supine plasma NE, epinephrine, and MAP 2 weeks after the onset of dieting. PRA decreased after 8 weeks of dieting in both obese groups, and these PRA decrements were correlated with reductions in MAP and decrements in plasma NE. We conclude that enhanced sympathetic activity may play a role in the maintenance of elevated blood pressure in obese individuals. Decreases in PRA and blood pressure associated with weight loss in both normotensive and hypertensive obese individuals occurs, in part, secondary to reductions in plasma NE levels.

Adult↗
PubMed1981

The effect of weight reduction on blood pressure, plasma renin activity, and plasma aldosterone levels in obese patients.

We investigated the relation between changes in the renin-aldosterone axis and reduction in blood pressure in 25 obese patients placed on a 12-week reducing diet; sodium intake was either medium (120 mmol) or low (40 mmol). Plasma renin activity (PRA) declined with weight loss, so that by 12 weeks there was a significant decrease in PRA (P less than 0.01) as well as plasma aldosterone (P less than 0.05), regardless of sodium intake. Weight loss with low sodium intake was equal to that with medium intake. The reduction in PRA but not in aldosterone correlated with weight loss in both sodium-intake groups (r = 0.58). Mean arterial pressure fell significantly and equally in both groups, correlating with weight loss throughout the study (r = 0.56) and with PRA from the fourth through 12th weeks (r = 0.48) These results demonstrate that weight loss is accompanied by reductions in PRA and aldosterone; PRA reductions, irrespective of sodium intake, may contribute to the decline in blood pressure.

Adult↗
PubMed1978

Longterm survival of lupus nephritis patients treated with azathioprine and prednisone.

Forty-seven SLE patients with severe renal disease characterized by renal biopsy documentation of diffuse proliferative or membranous glomerulonephritis or the nephrotic syndrome have been treated with azathioprine and prednisone in combination and followed for up to 12 years. Survivorship was 82% +/- 6% for five years and 74% +/- 8% for 10 years. There have been eight deaths and two patients have gone on hemodialysis. Five of the eight deaths are attributable to superinfection. Improvement in creatinine clearance was documented in 21 and decreased proteinuria in 35 of the patients. A therapeutic program, which included high dose corticosteroids initially, the combinations of azathioprine with corticosteroids chronically, and the rapid reduction in corticosteroid dosage to an alternate day schedule, appears to contribute to improved survivorship.

Adolescent↗
PubMed1977

Reversible crescentic glomerulonephritis following an acute exacerbation of chronic relapsing pancreatitis.

A patient had recurrent episodes of acute glomerulonephritis following exacerbations of chronic relapsing pancreatitis. Light microscopy of the renal biopsy performed during the episode of acute glomerulonephritis showed fibroepithelial crescents involving 70% of the glomeruli. The patient recovered without specific therapy. The time interval involved and the presence of subendothelial deposits with mesangial deposition of C3 complement and IgM suggest immune complex injury.

Acute Disease↗
PubMed1976

Immunologic considerations in renovascular hypertension.

For decades certain diseases, such as glomerulonephritis, polyarteritis nodosa, scleroderma and serum sickness, have been linked with autoimmune pathogenesis. During recent years a host of additional diseases traditionally thought to have some genetic predisposition but with obscure etiology have been suspected of being autoimmune in nature. Rheumatoid arthritis, diabetes, myasthenia gravis and thyroiditis are diseases of widely divergent organ systems, yet may well have common pathways of pathology via immune complexing mechanisms. Herein we present evidence supporting the concept that renal artery stenosis (occurring primarily in association with the middle aortic syndrome or after renal transplantation) is of immune etiology. Although the specific antigenic agent is still to be defined there is growing acceptance of the theory that medium and large vessels are subject to autoimmune vasculitis in many aspects similar to the autoimmune affections of small vessels. Several cases are presented. Some of these suggest an immune reaction by the natural history but without evidence of immunochemical reactants in the involved vessels, presumably because active disease was arrested at the time of study. In other cases immunofluorescent preparations demonstrate reactants in the walls of the vessels to document the hypothesis more convincingly.

Adolescent↗