10 results on '"Alboim S"'
Search Results
2. Role of protein kinase C in insulin activation of the Na-K pump in cultured skeletal muscle
- Author
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Sampson, S. R., primary, Brodie, C., additional, and Alboim, S. V., additional
- Published
- 1994
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3. Characterization and regulation of apamin-binding K+ channels in skeletal muscle.
- Author
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Vigdor-Alboim, Sandra, Bak, Asia, Sampson, Sanford R., Vigdor-Alboim, S, and Sampson, S R
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- 1996
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4. Cushing's syndrome in women: age-related differences in etiology and clinical picture.
- Author
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Akirov A, Dery L, Fleseriu M, Rudman Y, Shimon I, Manisterski Y, Aviran-Barak N, Nadler V, Alboim S, Shochat T, Tsvetov G, and Hirsch D
- Subjects
- Humans, Female, Adult, Middle Aged, Aged, Retrospective Studies, Hydrocortisone, Weight Gain, Cushing Syndrome diagnosis, Cushing Syndrome etiology, Pituitary ACTH Hypersecretion diagnosis
- Abstract
Objective: To evaluate the clinical presentation, biochemical profile, and etiology of Cushing's syndrome (CS) in women stratified by age., Methods: Retrospective study of patients with CS, treated at Rabin Medical Center from 2000 to 2020, or Maccabi Healthcare Services in Israel from 2005 to 2017. Disease etiology, presentation and biochemical profile were compared according to age at diagnosis: ≤ 45, 46-64, or ≥ 65 years. Study was approved by the Ethics Review Boards of both facilities with waiver of consent., Results: The cohort included 142 women (mean age, 46.0 ± 15.1 years):81 (57.0%) with Cushing's disease (CD), and 61 (43.0%) with adrenal CS. Pituitary etiology was more common among women < 45 (70.6%), compared with patients ≥ 65 years (31.6%) (P < 0.05). Among CS patients, hypercortisolism was diagnosed in the context of screening after an adrenal incidentaloma detection in 15.0% of patients < 45 and 53.8% of ≥ 65 years (P < 0.001). Weight gain was evident in 57.4% of women < 45 (56.3% CD, 60.0% CS), and 15.8% of women ≥ 65 years (50% CD, 0% CS) (P = 0.011). Mean UFC levels were highest for women < 45 (3.8 × ULN) and lowest for ≥ 65 years (2.3 × ULN) (P < 0.001)., Conclusion: We have shown for the first time that women with CS ≥ 65 years of age more commonly have adrenal etiology. The initial presentation of CS also differs between age groups, where women < 45 years are likely to present with weight gain, while those ≥ 65 years are frequently diagnosed incidentally, when screening for hypercortisolism in the presence of an adrenal incidentaloma., (© 2022. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)
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- 2023
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5. Screening for non-classic congenital adrenal hyperplasia in women: New insights using different immunoassays.
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Nakhleh A, Saiegh L, Shehadeh N, Weintrob N, Sheikh-Ahmad M, Supino-Rosin L, Alboim S, Gendelman R, and Zloczower M
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- Humans, Female, Retrospective Studies, 17-alpha-Hydroxyprogesterone, Immunoassay, Cosyntropin, Follicle Stimulating Hormone, Adrenal Hyperplasia, Congenital diagnosis
- Abstract
Context: The 250µg-cosyntropin stimulation test (CST) is used to diagnose non-classic congenital adrenal hyperplasia (NCCAH). The current recommendation is to perform CST when follicular 17-hydroxyprogesterone (17OHP) is 6-30 nmol/L, a cutoff derived from radioimmunoassay (RIA). Recently, enzyme-linked immunosorbent assay (ELISA) has replaced RIA., Objectives: We aimed to (1) determine the RIA and ELISA-based 17OHP cutoffs at which CST should be performed, (2) identify predictors of NCCAH., Methods: A retrospective study at an Israeli Health Maintenance Organization. Data were retrieved from women with suspected NCCAH, referred for CST during 2001-2020. NCCAH was defined as a stimulated 17OHP >30 nmol/L. Serum 17OHP levels were assayed by RIA from 1/2000-3/2015, and by ELISA from 4/2015-12/2020. ROC curves were generated and optimal 17OHP thresholds were determined. Multivariate analysis was performed., Results: CST was performed in 2409 women (1564 in RIA, 845 in ELISA). NCCAH was diagnosed in 4.7% of the RIA group and 7.5% of the ELISA group. The optimal basal 17OHP cutoff values predicting NCCAH were 6.1 nmol/L in RIA (sensitivity=93.2%, specificity=91.7%) and 8.2 nmol/L in ELISA (sensitivity=93.7%, specificity=92.3%). In multivariate analysis, higher basal 17OHP, lower LH: FSH ratio, and oligomenorrhea were predictors of NCCAH in RIA. Higher basal 17OHP, androstenedione, and total testosterone were predictors of NCCAH in ELISA. A lower LH: FSH ratio showed similar trend in ELISA., Conclusions: Optimal RIA-based basal 17OHP cutoff was comparable with that recommended in guidelines. The results suggest adopting a higher 17OHP cutoff when using ELISA. LH : FSH ratio improves the negative predictive value of basal 17OHP., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Nakhleh, Saiegh, Shehadeh, Weintrob, Sheikh-Ahmad, Supino-Rosin, Alboim, Gendelman and Zloczower.)
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- 2023
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6. Clinical Study and Systematic Review of Pituitary Microadenomas vs. Macroadenomas in Cushing's Disease: Does Size Matter?
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Akirov A, Shimon I, Fleseriu M, Dotan I, Manisterski Y, Aviran-Barak N, Nadler V, Alboim S, Shochat T, Tsvetov G, and Hirsch D
- Abstract
Background : Reports on clinical and biochemical differences between adrenocorticotropic hormone (ACTH)-secreting pituitary microadenomas and macroadenomas are limited and inconsistent. Objective: Compare clinical and biochemical characteristics of patients with corticotroph microadenomas and macroadenomas and assess predictive factors for biochemical response to dynamic testing for Cushing's disease (CD) in a clinical trial and a systematic review. A second aim was to evaluate differences between macroadenomas with and without cavernous and sphenoid sinus invasion. Methods: Retrospective charts review of patients with CD, treated at Rabin Medical Center between 2000 and 2020 or at Maccabi Healthcare Services in Israel between 2005 and 2017. Clinical and biochemical factors were compared between patients with corticotroph microadenomas and macroadenomas. We have also performed a systematic review of all studies (PRISMA guidelines) comparing corticotroph microadenomas with macroadenomas up to 31 November 2021. Results : The cohort included 105 patients (82 women, 78%; mean age, 41.5 ± 14.5 years), including 80 microadenomas (mean size, 5.2 ± 2.2 mm) and 25 macroadenomas (mean size, 18.0 ± 7.7 mm). Other baseline characteristics were similar between groups. Most common presentation suggestive for hypercortisolemia among patients with both micro- and macroadenomas were weight gain (46.3% vs. 48.0%, p = NS) and Cushingoid features (27.5% vs. 20.0%, p = NS). Mean 24 h urinary free cortisol (5.2 ± 5.4 × ULN vs. 7.8 ± 8.7 × ULN) and serum cortisol following low-dose dexamethasone (372.0 ± 324.5 vs. 487.6 ± 329.8 nmol/L), though higher for macroadenomas, were not significant. Levels of ACTH were greater for macroadenomas (1.9 ± 1.2 × ULN vs. 1.3 ± 0.8 × ULN, respectively, p = 0.01). Rates of recurrent/persistent disease were similar, as were rates of post-operative adrenal insufficiency and duration of post-operative glucocorticoid replacement. Macroadenomas with sphenoid or cavernous sinus invasion were associated with higher ACTH, 24 h free urinary cortisol, and serum cortisol following low-dose dexamethasone, compared with suprasellar or intrasellar macroadenomas. Conclusions: While ACTH-secreting macroadenomas exhibit higher plasma ACTH than microadenomas, there was no association between tumor size with cortisol hypersecretion or clinical features of hypercortisolemia. Though overall rare, increased awareness is needed for patients with CD with tumor extension in the cavernous or sphenoid sinus, which displays increased biochemical burden, highlighting that extent/location of the adenoma may be more important than size per se. Our systematic review, the first on this topic, highlights differences and similarities with our study.
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- 2022
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7. Pheochromocytoma: Positive predictive values of mildly elevated urinary fractionated metanephrines in a large cohort of community-dwelling patients.
- Author
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Hirsch D, Grossman A, Nadler V, Alboim S, and Tsvetov G
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- Adrenal Gland Neoplasms diagnosis, Adrenal Gland Neoplasms epidemiology, Adrenal Gland Neoplasms metabolism, Adult, Aged, Cohort Studies, Female, Humans, Hypertension diagnosis, Hypertension epidemiology, Independent Living statistics & numerical data, Israel epidemiology, Male, Middle Aged, Paraganglioma diagnosis, Paraganglioma metabolism, Paraganglioma pathology, Pheochromocytoma metabolism, Pheochromocytoma pathology, Predictive Value of Tests, Retrospective Studies, Adrenal Gland Neoplasms pathology, Hypertension etiology, Metanephrine urine, Pheochromocytoma diagnosis
- Abstract
The diagnostic utility of different thresholds of elevated urinary fractionated metanephrine (UFM) for pheochromocytoma-paraganglioma (PPGL) was evaluated in 10 164 community-dwelling subjects (2012-2017). Levels were ≥1.5× the upper normal limit (UNL) in 276 subjects (2.7%) and ≥2×UNL in 138 (1.4%). PPGL was subsequently diagnosed in 59 (mean age 51.9 ± 14.3, 64% female); 58 (98.3%) with UFM ≥ 2×UNL. Positive predictive values (PPV) were 42% for UFM ≥ 2×UNL, 55% for UFM ≥ 2.5×UNL, and 69% for UFM ≥ 3×UNL. The main reason for PPGL screening (52.5%) was adrenal incidentaloma. Mean (median) metanephrine/normetanephrine levels were 6.7 ± 9×UNL (3 × UNL) and 6.1 ± 8.9×UNL (2.5 × UNL). Six patients (10.2%) had an extra-adrenal tumor (one malignant paraganglioma); one had bilateral pheochromocytoma. Only one patient presented with the "classic triad" (headache, palpitations, sweating). In conclusion, after excluding obvious reasons for false-positive results, thorough diagnostic assessment for PPGL is justified in all subjects with UFM ≥ ×2UNL. The PPV of milder UFM elevations is very low., (©2019 Wiley Periodicals, Inc.)
- Published
- 2019
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8. Cushing's syndrome: comparison between Cushing's disease and adrenal Cushing's.
- Author
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Hirsch D, Shimon I, Manisterski Y, Aviran-Barak N, Amitai O, Nadler V, Alboim S, Kopel V, and Tsvetov G
- Subjects
- ACTH-Secreting Pituitary Adenoma blood, Adrenal Gland Neoplasms blood, Adult, Aged, Cushing Syndrome blood, Cushing Syndrome etiology, Female, Humans, Hydrocortisone blood, Male, Middle Aged, Pituitary ACTH Hypersecretion blood, Pituitary ACTH Hypersecretion etiology, Retrospective Studies, ACTH-Secreting Pituitary Adenoma complications, Adrenal Gland Neoplasms complications, Cushing Syndrome diagnosis, Pituitary ACTH Hypersecretion diagnosis
- Abstract
Purpose: The most common etiology of Cushing's syndrome (CS) is an ACTH-producing pituitary adenoma (pitCS), reported as 2-3 times more frequent than primary adrenal CS (adrCS). We aimed to analyze and compare features of patients with pitCS and adrCS., Methods: A retrospective file review of 196 consecutive patients (age 46.8 ± 15.6 years, 76% female) diagnosed with CS in 2000-2017 and followed for 5.2 ± 4.2 years; 109 (55.6%) had pitCS and 76 (38.8%) adrCS. Epidemiologic, clinical and biochemical factors were compared between and within the pitCS and adrCS groups., Results: The relative proportion of pitCS to adrCS (1.4) was lower than previously reported and gradually decreased during the study years to only 1.2 in 2012-2017. The most common reason for CS screening was weight-gain in the pitCS group (48.6%) and adrenal incidentaloma in the adrCS group (39.5%). The pitCS patients were diagnosed at younger age (42.5 ± 15.1 vs. 51.6 ± 15.1 years, p < 0.001) and had lower prevalence of hypertension (51.4 vs. 74%, p = 0.005). There was no between-group difference in severity of hypercortisoluria. Within the adrCS group, patients diagnosed after detection of an adrenal incidentaloma had milder hypercortisoluria than the remaining patients, presented with smaller adrenal lesions (35.9 ± 16.3 vs. 49.1 ± 33.7 cm, p = 0.04), and received post-adrenalectomy glucocorticoid treatment for shorter periods (13 ± 11.6 vs. 31 ± 40 months, p = 0.04)., Conclusions: The relative proportion of adrCS to pitCS is rising, probably because of an increasing detection of cortisol-secreting adrenal incidentalomas associated with milder hypercortisolism. There is no difference between pitCS and adrCS in the severity of hypercortisoluria, although significant clinical differences were found.
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- 2018
- Full Text
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9. Incidence of Cushing's syndrome in patients with significant hypercortisoluria.
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Hirsch D, Tsvetov G, Manisterski Y, Aviran-Barak N, Nadler V, Alboim S, and Kopel V
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- Adult, Female, Humans, Incidence, Male, Middle Aged, Retrospective Studies, Cushing Syndrome urine, Hydrocortisone urine
- Abstract
Objective: To investigate the incidence of Cushing's syndrome (CS) in patients with significant hypercortisoluria and the performance of urinary free cortisol (UFC) screening., Design: Retrospective file review., Methods: The computerized database of a publicly funded health maintenance organization (HMO) in Israel was searched for all patients who underwent 24-h UFC testing in 2005-2014 with a result of more than twice the upper limit of normal (ULN). The patients' medical files were reviewed for a subsequent diagnosis of CS by an expert endocrinologist. Findings were evaluated for patterns in CS diagnosis and UFC testing over time., Results: Of 41 183 individuals tested, 510 (1.2%) had UFC >2× ULN (214 >3× ULN). Eighty-five (16.7%) individuals were diagnosed with CS (63 female and mean age 47.2 ± 15.1 years), mainly Cushing's disease (55.3%) or adrenal Cushing's syndrome (37.6%). The number of UFC tests increased steadily, from 1804 in 2005 to 6464 in 2014; yet, the resultant detection rate of CS remained generally stable. The calculated incidence of CS in the general HMO-insured population based only on the patients identified in the present cohort was 4.5 new cases/million/year (median 4.9/million/year, range 1.7-5.9/million/year), which was also relatively stable. The most common reason for referral for UFC screening was obesity. Of the 148 patients before bariatric surgery with UFC >2× ULN, 2 were diagnosed with CS., Conclusions: The incidence of CS is higher than previously suggested. The consistently increasing number of UFC tests being performed has not been accompanied by a similar increase in CS detection rate. The expected yield of routine UFC testing before bariatric surgery is low., (© 2017 European Society of Endocrinology.)
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- 2017
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10. Tunicamycin reduces Na(+)-K(+)-pump expression in cultured skeletal muscle.
- Author
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Alboim SV, Bak A, and Sampson SR
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- Animals, Cells, Cultured, Chick Embryo, Gene Expression, Membrane Potentials, Muscles cytology, Ouabain metabolism, Rubidium metabolism, Sodium-Potassium-Exchanging ATPase drug effects, Sodium-Potassium-Exchanging ATPase physiology, Tetrodotoxin pharmacology, Muscles enzymology, Sodium-Potassium-Exchanging ATPase genetics, Tunicamycin pharmacology
- Abstract
The purpose of this study was to examine effects of tunicamycin (TM), which inhibits core glycosylation of the beta-subunit, on functional expression of the Na(+)-K+ pump in primary cultures of embryonic chick skeletal muscle. Measurements were made of specific-[3H]-ouabain binding, ouabain-sensitive 86Rb uptake, resting membrane potential (Em), and electrogenic pump contribution to Em (Ep) of single myotubes with intracellular microelectrodes. Growth of 4-6-day-old skeletal myotubes in the presence of TM (1 microgram/ml) for 21-24 hr reduced the number of Na(+)-K+ pumps to 60-90% of control. Na(+)-K+ pump activity, the level of resting Em and Ep were also reduced significantly by TM. In addition, TM completely blocked the hyperpolarization of Em induced in single myotubes by cooling to 10 degrees C and then re-warming to 37 degrees C. Effects of tunicamycin were compared with those of tetrodotoxin (TTX; 2 x 10(-7) M for 24 hr), which blocks voltage-dependent Na+ channels. TM produced significantly greater decreases in ouabain-binding and Em than did TTX, findings that indicate that reduced Na(+)-K+ pump expression was not exclusively secondary to decreased intracellular Na+, the primary regulator of pump synthesis in cultured muscle. Similarly, effects of TM were significantly greater than those of cycloheximide, which inhibits protein synthesis by 95%. These findings demonstrate that effects were not due to inhibition of protein synthesis. We conclude that glycosylation of the Na(+)-K+ pump beta-subunit is required for full physiological expression of pump activity in skeletal muscle.
- Published
- 1992
- Full Text
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