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Biomedical subjects

Y Liel

Publications and source records attributed to Y Liel.

At least 37 records · Page 2Linked to original sources
PubMed1994

Monocyte dysfunction in patients with Gaucher disease: evidence for interference of glucocerebroside with superoxide generation.

Gaucher disease patients are occasionally affected by chronic or fulminant infections. Since Gaucher cells originate from tissue phagocytes, we studied the functional implications of glucocerbroside accumulation on phagocytes in Gaucher disease patients. Circulating monocytes and granulocytes from nine type I Gaucher disease patients, and matched controls, were studied. Evaluation of phagocytic activity included (1) maximal superoxide generation rates following stimulation by phorbol 12-myristate 13-acetate (PMA), opsonized zymosan (OZ), or formyl-methionyl-leucylphenylalanine (FMLP); (2) nitroblue tetrazolium reduction test (NBT); (3) chemotaxis toward FMLP; (4) phagocytosis of OZ particles; and (5) killing activity against Staphylococcus aureus. Superoxide generation in monocytes following PMA, OZ, and FMLP stimulation was significantly suppressed at 52% +/- 15%, 39% +/- 8%, and 51% +/- 11% of control, respectively. Superoxide generation in granulocytes was normal. NBT reduction, staphylococcal killing, and phagocytosis were also markedly decreased in monocytes, and normal in granulocytes. Mean chemotaxis rates were normal in both monocytes and granulocytes; however, decreased chemotactic rates were observed in some patients. The abnormality of superoxide generation could be reproduced in a dose- and time-dependent manner in normal circulating monocytes incubated with glucocerebroside. Superoxide generation in glucocerebroside-conditioned normal monocytes in a cell-free system showed normal superoxide generation, reflecting the integrity of the NADPH oxidase complex itself. These results demonstrate markedly compromised phagocytic functions in circulating monocytes in Gaucher disease patients. These abnormalities can be attributed to accumulation of glucocerebroside, since it could be reproduced in normal monocytes incubated with glucocerebroside. Similar abnormalities in Gaucher cells throughout the reticuloendothelial system could impair host defense, and may be of particular importance in the pathogenesis of osteomyelitis in Gaucher disease patients.

Adult↗
PubMed1994

Demographic aspects of Paget's disease of bone in the Negev of southern Israel.

In a mainly retrospective but partly prospective survey of the period 1968-1993 in southern Israel, 61 cases of Paget's disease of bone were identified. Fifty six percent were of non-Afro-Asian origin and 44% originated from Afro-Asia, which is approximately the inverse of the ratio in the local general population. The largest single groups from non-Afro-Asia and Afro-Asia originated, from Romania and Tunisia, respectively, and Australia and Argentina were also disproportionately prominent as countries of origin. Israel itself was the origin of few patients. All the patients were Jews except for one Bedouin Arab, which is far different from the distribution of Bedouins and Jews in both the surveyed area and the hospital population. The differences between these groups numerically and against the background local population may well have been statistically significant had the circumstances enabled greater randomness in the collection of the data analyzed. It is surmised that in southern Israel the prevalence of Paget's disease of bone is about 1%, similar to that in southern Europe.

Africa↗
PubMed1994

Nonspecific intestinal adsorption of levothyroxine by aluminum hydroxide.

PURPOSE: To evaluate the adverse effect of aluminum hydroxide on levothyroxine pharmacokinetics in hypothyroid patients and study the mechanism of this effect. DESIGN: An in vivo open study supplemented by in vitro experiments. SETTING: A university hospital-based outpatient service. INTERVENTION: Administration for 2 to 4 weeks of an aluminum hydroxide-containing preparation to patients balanced on replacement thyroxine therapy. MEASUREMENTS: Serum thyrotropin (TSH). RESULTS: A significant increase in serum TSH was observed during seven periods of aluminum hydroxide administration (7.19 +/- 1.3 versus 2.62 +/- 0.8 mU/L; P = 0.012). In vitro studies indicated a considerable nonspecific adsorptive capacity of aluminum hydroxide for thyroxine. CONCLUSIONS: The results indicate an adverse effect of aluminum hydroxide on levothyroxine bioavailability through a mechanism involving nonspecific adsorption, or complexing, of levothyroxine to aluminum hydroxide. We recommend close monitoring of serum TSH levels in patients receiving oral thyroid hormone replacement therapy who concurrently take aluminum hydroxide-containing medications. Adjustment of the levothyroxine dose, or cessation of the antacid, may be necessary.

Adsorption↗
PubMed1993

Acute adrenal crisis complicating hypertensive congenital adrenal hyperplasia due to 11 beta-hydroxylase deficiency.

In its classical form, congenital adrenal hyperplasia due to 11 beta-hydroxylase deficiency is characterized by hypertension and abnormal sexual development. Suppression of ACTH secretion by means of administering glucocorticoids fulfills the therapeutic goal of reducing blood pressure and decreasing androgen production. The present report describes the case of a patient suffering from congenital adrenal hyperplasia due to 11 beta-hydroxylase deficiency who developed an acute adrenal crisis, unprovoked by stress, following interruption of glucocorticoid replacement therapy. It is suggested that patients on a suppressive dose of glucocorticoids for adrenal hyperplasia are at increased risk for acute adrenal insufficiency if therapy is interrupted, and that deoxycorticosterone (DOC) in the absence of a glucocorticoid is insufficient to prevent manifestations of adrenal crisis.

Acute Disease↗
PubMed1993

Increased calcium intake does not suppress circulating 1,25-dihydroxyvitamin D in normocalcemic patients with sarcoidosis.

Ca absorption is regulated by 1,25(OH)2D, and serum values vary inversely with Ca intake. In sarcoidosis, 1,25(OH)2D is produced by alveolar macrophages in response to gamma-interferon, and patients may develop hypercalcemia after prolonged exposure to sunlight and increased dermal production of vitamin D3. To determine if increased Ca intake suppresses serum 1,25(OH)2D in normocalcemic patients and to identify those at risk, 17 normal subjects and 11 patients were studied on a metabolic ward for two and one-half days while receiving first 400 and then 1,000 mg/d of Ca. On the low Ca intake, serum angiotensin-converting enzyme (ACE), an index of disease activity, was higher in only three of the patients than in the controls, mean serum 1,25(OH)2D was higher in the patients, and mean serum total Ca, serum Ca++, and urinary Ca were not different in the two groups. On the higher Ca intake, mean urinary Ca increased in both groups, but mean serum 1,25(OH)2D was suppressed only in the normal subjects. Thus, 1,25(OH)2D production is abnormally regulated, indicating that (a) normocalcemic patients with sarcoidosis are at risk for developing abnormal Ca metabolism, and (b) a better index of disease activity is provided by the oral Ca suppression test than by serum ACE.

Adult↗
PubMed1992

Evidence that estrogens modulate activity and increase the number of 1,25-dihydroxyvitamin D receptors in osteoblast-like cells (ROS 17/2.8).

A detailed understanding of the mechanism of action of estrogen on bones is still lacking. The present study was designed to examine possible modulation by 17 beta-estradiol (E2) on the effects of 1,25-dihydroxyvitamin D3 [1,25-(OH)2D3] and on vitamin D receptors (VDR) in the ROS 17/2.8 osteoblast-like cell line. Cells were grown in phenol-red free medium supplemented with charcoal-stripped fetal calf serum (FCS). Total cellular VDR were measured in cell homogenates after extraction with a KCl hypertonic buffer. VDR-binding capacity doubled in the presence of 10 nM E2 (16.2 +/- 2.3 vs. 7.0 +/- 1.3 fmol/mg protein, respectively; P less than 0.01), while the Kd for 1,25-(OH)2D3 did not change (approximately 0.1 nM). Tamoxifen alone had no effect on VDR, while it completely abolished the E2-induced increase in VDR, indicating that the effect was specific for E2 and estrogen receptor mediated. 1,25-(OH)2D3 inhibited cell proliferation, determined by [3H] thymidine incorporation to DNA, in a dose-dependent fashion between 0.01-100 nM. The inhibitory effect of 1,25-(OH)2D3 on cell proliferation was significantly augmented in the presence of E2 (10 nM). 1,25-(OH)2D3 increased osteocalcin secretion to the medium by the cells in a dose-dependent fashion between 0.01-100 nM. In the presence of E2 (10 nM), maximal osteocalcin secretion in response to 1,25-(OH)2D3 was 3.5-fold higher than that in response to 1,25-(OH)2D3 alone. These results indicate that E2 modulates 1,25-(OH)2D3 activity in osteoblast-like cells, and that this effect can be attributed to an increase in VDR.

Animals↗
PubMed1992

Evidence for interference with the intestinal absorption of levothyroxine sodium by aluminum hydroxide.

A patient with hypothyroidism who was euthyroid on a fixed-dosage, long-term maintenance regimen of levothyroxine sodium developed persistently elevated serum thyrotropin levels while receiving an aluminum hydroxide-containing antacid. The thyrotropin levels returned to normal shortly after cessation of the antacid therapy. These observations indicate that aluminum hydroxide may interfere with the bioavailability of thyroxine. The thyroid function of patients who are receiving replacement or suppressive thyroxine therapy should be monitored following the commencement of concurrent treatment with medications containing aluminum hydroxide.

Aluminum Hydroxide↗
PubMed1991

[Histiocytic necrotizing lymphadenitis of Kikuchi and Fujimoto].

Histiocytic necrotizing lymphadenitis of Kikuchi and Fujimoto (HNL) is a benign, self-limited disease of unknown etiology. It can easily be mistaken for lymphoma, both clinically and on pathological examination. We report a 25-year-old woman who presented with fever and painful unilateral lymphadenopathy, clinically compatible with, and histologically diagnosed as HNL. Only 2 previous cases of HNL have been reported from Israel.

Adult↗
PubMed1991

Case report: serendipitous Gaucher's disease presenting as elevated erythrocyte sedimentation rate due to monoclonal gammopathy.

Immunoglobulin abnormalities have not been previously noted in totally asymptomatic patients with Gaucher's disease. We report a 40-year-old woman in whom Gaucher's disease was diagnosed during investigation for incidentally discovered elevated erythrocyte sedimentation rate. Further studies revealed IgG(lambda) monoclonal gammopathy. Physical examination and a bone survey disclosed none of the features of Gaucher's disease or multiple myeloma. We conclude that in contrast with previous observations, paraproteinemia may occur with Gaucher's disease even in the absence of splenomegaly or any one of the other features of the disease.

Adult↗
PubMed1990

Alteration of vitamin D metabolism in Mexican-Americans.

Studies were performed to investigate vitamin D metabolism in Mexican-Americans. Groups of 15 whites and 16 Mexican-Americans ranging in age from 18 to 41 years were evaluated. All of them were within 25% of their ideal body weight. Each of them was admitted to the Clinical Research Center of the University of Texas Health Science Center and placed on a daily diet estimated to contain 400 mg calcium and 900 mg phosphate. It was found that whereas serum vitamin D (1.8 +/- 0.5 versus 7.6 +/- 1.3 ng/ml, P less than 0.001) and serum 25-hydroxyvitamin D (9 +/- 1 versus 17 +/- 2 ng/ml, P less than 0.01) were significantly lower and serum 1,25-dihydroxyvitamin D (37 +/- 2 versus 28 +/- 2 pg/ml, P less than 0.001) was significantly higher in the Mexican-Americans than in the whites, serum calcium (9.1 +/- 0.1 versus 9.2 +/- 0.1 mg/dl), magnesium (1.84 +/- 0.07 versus 1.80 +/- 0.07 mEq/liter), and Gla protein (19 +/- 3 versus 21 +/- 2 ng/ml) were not different in the two groups. Urinary calcium (144 +/- 14 versus 124 +/- 16 mg/day), phosphate (672 +/- 51 versus 683 +/- 44 mg/day), sodium (110 +/- 8 versus 99 +/- 9 mEq/day), potassium (43 +/- 4 versus 49 +/- 3 mEq/day), and magnesium (7.3 +/- 0.7 versus 7.7 +/- 0.5 mEq/day) and creatinine clearance (173 +/- 14 versus 154 +/- 7 liters/day) were not different in the two groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗