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Biomedical subjects

G Halaby

Publications and source records attributed to G Halaby.

At least 19 recordsLinked to original sources

Diabetes mellitus and optic atrophy: a study of Wolfram syndrome in the Lebanese population.

Wolfram syndrome (WFS) is a rare hereditary neurodegenerative disorder also known as DIDMOAD (diabetes insipidus, diabetes mellitus, optic atrophy, and deafness). WFS seems to be a heterogeneous disease that has not yet been fully characterized in terms of clinical features and pathophysiological mechanisms because the number of patients in most series was small. In this study we describe 31 Lebanese WFS patients belonging to 17 families; this, to our knowledge, is the largest number of patients reported in one series so far. Criteria for diagnosis of WFS were the presence of insulin-dependent diabetes mellitus and optic atrophy unexplained by any other disease. Central diabetes insipidus was found in 87% of the patients, and sensorineural deafness confirmed by audiograms was present in 64.5%. Other less frequent features included neurological and psychiatric abnormalities, urodynamic abnormalities, limited joint motility, cardiovascular and gastrointestinal autonomic neuropathy, hypergonadotropic hypogonadism in males, and diabetic microvascular disease. New features, not reported in previous descriptions, such as heart malformations and anterior pituitary dysfunction, were recognized in some of the patients and participated in the morbidity and mortality of the disease. Genetic analysis revealed WFS1 gene mutations in three families (23.5%), whereas no abnormalities were detected in mitochondrial DNA. In conclusion, WFS is a devastating disease for the patients and their families. More information about WFS will lead to a better understanding of this disease and hopefully to improvement in means of its prevention and treatment.

Adolescent↗

Effects of a short-term calcium and vitamin D treatment on serum cytokines, bone markers, insulin and lipid concentrations in healthy post-menopausal women.

In vitro studies have shown that 1,25 dihydroxyvitamin D3 [1,25(OH)2D3] decreases cytokine production by monocytes and lymphocytes. In addition, intravenous or oral pulse calcitriol treatment suppresses interleukin 6 (IL6) and interleukin1beta (IL1beta) in hemodialysis patients. We studied the effect of a daily 12-week course of 1000 mg calcium and 800 U cholecalciferol on circulating 25 hydroxyvitamin D [25(OH)D], PTH, cytokines, osteoprotegerin (OPG), C-reactive protein (CRP), bone markers, lipid parameters and insulin levels in 47 healthy post-menopausal women. Thirty-nine women completed the study. A significant increase in 25(OH)D and a significant decrease in PTH were observed (p=0.0043 and p<0.0001, respectively). In addition, alkaline phosphatase, osteocalcin and, to a lesser extent, urinary free deoxypiridinoline (DPD) decreased significantly (p<0.0001, p=0.0002 and p=0.026, respectively). No change in circulating IL6, tumor necrosis factor alpha (TNFalpha), CRP, OPG, triglycerides, LDL- and HDL-cholesterol, and insulin levels was observed. Correlation studies in the 47 women enrolled in the study revealed inverse significant correlations between OPG on one side and body mass index, LDL-cholesterol, IL6, CRP and insulin levels on the other (p=0.002, p=0.002, p=0.004, p=0.023 and p=0.0001). Also, IL6 was significantly correlated with insulin levels (p=0.0005). In a multivariate model, both insulin and LDL-cholesterol were independently associated with OPG, while only insulin was independently associated with IL6. Our results showed no effect of a short-term calcium-vitamin D treatment on circulating cytokines, CRP, insulin levels and lipid parameters. This could be related to the low circulating cytokine concentrations in healthy subjects or to the short duration of treatment. The interesting association we found between OPG and some cardiovascular risk markers deserves further investigation.

Aged↗

Host and environmental factors defining the epidemiology of type 1 diabetes mellitus in a group of Lebanese children and young adults.

The effect of a number of host and environmental factors on the onset of type 1 diabetes mellitus (DM1) in a group of Lebanese children and young adults was studied. Results showed that DM1 in a group of 253 patients presented no gender preference and that the age of onset was similar in both genders. The overall body mass index reflected good metabolic control. HbA1c had a mean value of 8.98%, suggesting poor glucose control. Family history of DM1 and type 2 diabetes mellitus as well as consanguinity in patients' families were not different from those reported in the literature. Finally, onset of DM1 showed seasonal variation, peaking during winter months. DM1 showed a higher prevalence of onset among children born first and a decreased incidence as birth order increased. This study provides valuable data for the diagnosis, control and prevention of DM1 in children.

Adolescent↗

Type-2 diabetes family history delays the onset of type-1 diabetes.

Type-1 diabetes (T1D) is an autoimmune disease leading to insulin deficiency. Its occurrence is influenced by genetic and environmental factors. The human leukocyte antigen (HLA) region on chromosome 6 accounts for 45% of the genetic susceptibility for the disease, mainly the HLA-DQB1*0201 and HLA-DQB1*0302 alleles. Among the environmental factors involved, early exposure to cow's milk seems to be a trigger. In this study, we investigated the occurrence of T1D in 253 Lebanese Caucasian patients, in relation to HLA-DQB1*0201, HLA-DQB1*0302, HLA-DQB1*0602, gender, and early exposure to cow's milk, as well as to family history of T1D and type-2 diabetes (T2D). Our genetic analysis results show that in the patients studied, 77% and 40% were positive for BQ1*0201 and BQ1*0302, respectively. As for BQ1*0602, only 0.8% of patients were positive for this T1D protective allele, compared with 24% among the controls. Furthermore, our results did not show any gender preference of the disease or any effects of early intake of cow's milk on the age at onset of T1D. When family history of T2D or T1D was studied, our results show a novel finding whereby an immediate family history of T2D, but not T1D, delays the age at onset of T1D.

Adult↗

[Hypovitaminosis D: a major worldwide public health problem].

PHYSIOLOGY: Vitamin D increases intestinal absorption of calcium favoring the microenvironment necessary for bone mineralization. In addition, vitamin D prevents hypocalcemia via its osteoclastic action. Severe hypovitaminosis leads to rickets in children and its equivalent in adults, osteomalacia. Mild to moderate hypovitaminosis D causes secondary hyperparathyroidism increasing the risk of fracture, particularly femoral neck fracture. Vitamin D would also have an antiinflammatory and anticancer effect. WORLDWIDE: Hypovitaminosis D is frequently observed in Europe in the elderly, particularly in the institutionalized population, but is also seen in otherwise healthy younger adults. An estimated 40% of the young European population has some degree of hypovitaminosis D. Surprisingly, it is more frequent in sunny Mediterranean countries than in certain northern countries such as Norway. The lower incidence observed in the United States is probably related to the vitamin D supplementation of the American diet. Hypovitaminosis D in Africa and the Middle-East is also an important problem, being considered to be one of the 5 most prevalent childhood diseases in developing countries. ENVIRONMENTAL FACTORS: The limited quantity of vitamin D in food and multiple environmental factors contribute to hypovitaminosis D. These factors include insufficient sun exposure and urban lifestyle with a high degree of pollution. In addition, cutaneous photosynthesis of vitamin D is limited by hyperpigmentation in black people, wearing traditional veils that limit sun exposure, and use of sun lotions, further contributing to vitamin D deficiency. CONCLUSIONS AND RECOMMENDATIONS: The very high prevalence of hypovitaminosis D in the world, and particularly in Europe, Africa and the Middle-East, points to the need for public health measures in these countries. While waiting for these measures to be implemented, vitamin D supplementation (for example in tablet form) should be encouraged in order to meet minimum requirements. Finally, the beneficial effect of moderate sun exposure on cutaneous vitamin D synthesis (and psychological well-being) must not be overlooked.

Adult↗

Malignant struma ovarii: an unusual presentation.

Malignant struma ovarii is a rare disease; only a few cases are well documented in the literature. Thus, the overall prognosis and modalities of treatment are still somewhat controversial. In this article, the authors report a case of malignant struma ovarii discovered 4 years after ovariectomy after metastasis to the lungs and bones. Review of the pathology of the ovarian struma did not reveal the classic criteria of malignancy, there were, however, many features considered to be atypical and thus suspicious. The patient was treated by total thyroidectomy followed by repetitive doses of 131I. However, because of difficulties in increasing the level of endogenous thyrotropin (TSH) because of functional thyroid metastases in such an advanced disease, recombinant human thyrotropin (rhTSH; Thyrogen, thyrotropin alpha, Genzyme Corporation, Cambridge, MA) was used before administration of radioiodine. With this therapeutic protocol, the patient is still clinically stable 2 years after diagnosis.

Adult↗

Mutational analysis in Lebanese patients with congenital adrenal hyperplasia due to a deficit in 21-hydroxylase.

Molecular defects in the gene encoding steroid 21-hydroxylase (CYP21) result in impairment of adrenal steroid synthesis in patients affected with autosomal-recessive congenital adrenal hyperplasias (CAH). In this study, we report on the molecular screening of six point mutations, large deletions, gene conversion events and duplications in 25 unrelated Lebanese families affected by CAH due to steroid 21-hydroxylase. The methods used (PCR-digestion and southern blot) allowed the detection of 96% of the disease chromosomes. In classical forms, the most frequent mutation was the splice site mutation in intron 2 accounting for 39% of the disease alleles. Gene conversion events accounted for 14% of the alleles, but no large deletions were found. In nonclassical forms, the V281L mutation in exon 7 represent 86% of the tested alleles. Genotype-phenotype correlations were as expected: Delta 8nt, Q318X and gene conversion correspond to SW forms, whereas the intron 2 splice site mutation may give either SW or SV forms; the V281L mutation was responsible for nonclassical forms. The spectrum of mutations underlines the genetic diversity of the Lebanese population. No correlation could be drawn out between mutations and some specific religious communities, except for the Delta 8nt mutation, which is present only in the Christian Maronite group. Molecular study of the CYP21 gene might constitute a good support for clinicians, especially in consanguineous families, for whom we could provide genetic counselling.

Adolescent↗

Hypovitaminosis D in a sunny country: relation to lifestyle and bone markers.

Hypovitaminosis D is associated with poor dietary intake and inadequate sunshine exposure. It is common worldwide, particularly in European elderly people. Information about vitamin D status in young adult populations from the Middle East is scarce. Furthermore, the relationship between hypovitaminosis D and some lifestyle factors such as style of clothing and dwelling location is not well defined. We assessed vitamin D intake and measured serum calcium, phosphorus, albumin, alkaline phosphatase, 25-hydroxyvitamin D [25(OH)D], parathyroid hormone (PTH), osteocalcin, and urinary-free deoxypyridinoline (DPD) in 316 Lebanese volunteers (99 men and 217 women) aged 30-50 years; 156 were recruited from rural areas and 160 from urban areas. Fifty-one women from each area were veiled. The average daily vitamin D intake was 100.3 +/- 67.9 IU and was found to be higher in men compared with women, in urban subjects compared with rural ones and in nonveiled women compared with veiled ones. The mean level of 25(OH)D was 9.71 +/- 7.07 ng/ml. Hypovitaminosis D [25(OH)D < 12 ng/ml] affected 72.8% of our population. It was more common in women than in men (83.9% vs. 48.5%). Severe hypovitaminosis D [25(OH)D < 5 ng/ml] was observed in 30.7% of our subjects and was more prevalent in women (41.5%), particularly in the veiled ones (61.8%). 25(OH)D levels were the lowest in veiled women, and in women living in rural areas. Rural men had the highest 25(OH)D levels despite their very low vitamin D intake. In a multivariate model, inadequate vitamin D intake, urban dwelling, veil wearing, and high parity in women were independent predictors of hypovitaminosis D. 25(OH)D was related inversely to PTH and free DPD whereas osteocalcin achieved only a weak positive correlation with 25(OH)D. In the absence of information regarding time spent outdoors, our results show that hypovitaminosis D is common among young Lebanese people and is related mostly to low vitamin D intake. This should emphasize the need for more vitamin D in our population.

Adult↗

[Extrapontine myelinolysis: treatment with TRH].

Central pontine and extra-pontine myelinolysis are a well known complication of hyponatremia. Other causes may be present. We report a case of head injury in a 13 year-old girl, who recovered well after surgery for extra-dural hematoma, but presented endocrinological disorders with hyperglycemia followed by a severe hyponatremia. Despite the correction of these metabolic disorders, the patient became comatose, and MRI, on T2 weighted image, showed hyperintense signals in the basal ganglia consistent with extra-pontine myelinolysis. The patient's state remained unchanged for six weeks. Since S. Konno and H. Wakui published cases of myelinolysis who dramatically improved after TRH treatment, the patient was given 0.6 mg i.v daily of TRH for six weeks. Improvement began within a few days, and continued until complete recovery.

Adolescent↗

Heterogeneity in clinical manifestation of autosomal dominant neurohypophyseal diabetes insipidus caused by a mutation encoding Ala-1-->Val in the signal peptide of the arginine vasopressin/neurophysin II/copeptin precursor.

Autosomal dominant neurohypophyseal diabetes insipidus (ADNDI) is a familial form of diabetes insipidus due to progressive vasopressin deficiency with onset typically at 1-6 yr of age. Affected individuals demonstrate specific degeneration of the vasopressinergic magnocellular neurons in the hypothalamic supraoptic and paraventricular nuclei and loss of the posterior pituitary bright spot on magnetic resonance imaging. The genetic locus of ADNDI is the arginine vasopressin-neurophysin II (AVP-NPII) gene. Mutations that cause ADNDI have been found to occur both within the signal peptide of the prepro-AVP-NPII precursor and within the coding sequence for neurophysin II, but not within the coding sequence for AVP itself. We evaluated the AVP-NPII genes in two independent families with ADNDI and identified a mutation (C280-->T) in the coding sequence for the signal peptide of the prepro-AVP-NPII precursor in both families. This mutation encodes an Ala-->Val substitution at the C-terminus of the signal peptide (-1 amino acid). This mutation predicts the complete inability of signal peptidase to cleave the signal peptide from the preproprecursor and supports the hypothesis that the progressive neural degeneration that underlies ADNDI is caused by accumulation of malprocessed precursor. However, considerable heterogeneity in the age of onset (1-28 yr of age) and the severity of diabetes insipidus among affected members of these two families suggests that additional factors modulate the rate and extent of progression of the neurodegeneration that results from this one specific ADNDI mutation.

Alanine↗

Multiple independent molecular etiology for limb-girdle muscular dystrophy type 2A patients from various geographical origins.

Limb-girdle muscular dystrophies (LGMDs) are a group of neuromuscular diseases presenting great clinical heterogeneity. Mutations in CANP3, the gene encoding muscle-specific calpain, were used to identify this gene as the genetic site responsible for autosomal recessive LGMD type 2A (LGMD2A; MIM 253600). Analyses of the segregation of markers flanking the LGMD2A locus and a search for CANP3 mutations were performed for 21 LGMD2 pedigrees from various origins. In addition to the 16 mutations described previously, we report 19 novel mutations. These data indicate that muscular dystrophy caused by mutations in CANP3 are found in patients from all countries examined so far and further support the wide heterogeneity of molecular defects in this rare disease.

Adolescent↗

[Thyroid-stimulating hormone hypophyseal adenoma. A case report].

TSH pituitary adenomas represent less than 1% of operated pituitary adenomas. More then 200 cases have been described till now and more patients are now identified since the widespread of ultrasensitive TSH assay which can detect paradoxical situations of elevated serum thyroxine levels with detectable TSH levels. Differential diagnosis must be done with pituitary resistance to thyroid hormones, disorder in which there is a state of "TSH mediated hyperthyroidism". Transsphenoidal surgery remains the treatment of choice of TSH secreting adenoma. A medical treatment with octreotide can improve biological findings and induce tumor shrinking. We report in this paper a TSH pituitary adenoma in a young girl of 15 years old.

Adenoma↗

[Generalized amyloidosis associated with Hashimoto's thyroiditis and hypothyroidism].

Involvement of the thyroid gland in systemic amyloidosis is known since 1855, most frequently histologic than clinical. We report here a case of systemic amyloidosis associated with myxedema and Hashimoto's thyroiditis which has been rarely reported in the literature, and may represent a new example of auto-immune diseases associated with systemic amyloidosis.

Amyloidosis↗

[Significance of TSH receptor antibody determination].

TSH receptor antibodies (TRAb) was performed by binding assay in seventy-seven patients (47 with Graves disease, 32 with other thyroid abnormalities). The sensitivity and specificity of our assay were respectively 81% and 96.5%. These results were similar to the results found in medical literature. The association of ophthalmopathy with Graves disease does not increase the sensitivity of the test. In this study we conclude that TRAb assay is of great interest in confirming the diagnosis and in the following of Graves disease.

Adolescent↗

[Incidentally discovered adrenal tumor: myelolipoma].

The wider application of increasingly sensitive ultrasonography and CT scanning has created a new problem for clinical management: the incidental discovery of asymptomatic adrenal lesions. These lesions, also called "incidentalomas" may be due to a large variety of etiologies, and although most of them prove to be benign cortical adenomas, diagnostic confirmation is frequently impossible preoperatively. For this reason, a general approach, based on the relative prevalence of benign and malignant, clinically silent adrenal masses, has been defined. This same approach is usually needed in the case of myelolipoma, a rare form of benign and silent adrenal neoplasms, containing hematopoietic and fatty elements. Actually, computed tomographic aspect of such tumors is very evocative but not pathognomonic, so it doesn't eliminate the possibility of malignant lesions, especially in the presence of heterogeneities. Because of these limitations and awaiting the development of more specific diagnostic procedures, it seems cautious to approach these tumors like incidentalomas in general.

Adrenal Gland Neoplasms↗