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Biomedical subjects

A Zung

Publications and source records attributed to A Zung.

At least 19 recordsLinked to original sources
PubMed2004

Type 1 diabetes in Jewish Ethiopian immigrants in Israel: HLA class II immunogenetics and contribution of new environment.

The interrelationship between human leukocyte antigen immunogenetics and environmental factors and their contribution to the emergence of type 1 diabetes (T1D) were studied in Jewish immigrants from Ethiopia in Israel. This community displays high incidence of T1D, and is unique both by its ethnic segregation and its rapid exposure to a new environment after the immigration. The study population consisted of 152 Ethiopian Jews living in Israel, 33 with T1D and 119 unrelated controls. Human leukocyte antigen class II susceptible and protective alleles in the Jewish Ethiopian patients were similar to those in patients of other ethnic groups in Israel and in non-Jewish Ethiopian patients, with a few exceptions. Three haplotypes were markedly associated with diabetes in Jewish Ethiopian patients: DRB1*0301 DQA1*05 DQB1*02 (OR 4.4, p < 0.001); DRB1*0404 DQA1 03 DQB1*0302 (OR 19.2, p = 0.006), and DRB1*0405 DQA1*03 DQB1*0302 (OR 87.8, p < 0.001). The highly susceptible allele DRB1*0301 was more common in the general Ethiopian population (25.2%) than in all other ethnic groups in Israel, which may render this community prone to the disease. The age at onset of disease in patients with two susceptible haplotypes was negatively correlated with the duration of living in Israel (r = -0.621, p = 0.04). We concluded that ongoing exposure of genetically predisposed immigrants from Ethiopia to diabetogenic environmental factors eventually leads to a high incidence of overt diabetes in this ethnic group.

Adolescent↗
PubMed2004

Vitamin A and iron supplementation is as efficient as hormonal therapy in constitutionally delayed children.

OBJECTIVE: To assess the effect of nutritional supplementation on growth and puberty in constitutionally delayed children. PATIENTS: One hundred and two boys, 13.6-15.5 years of age, who were referred because of short stature and delayed puberty. METHODS: The boys were randomly allocated to one of the following treatment groups: oxandrolone therapy, 5 mg/day for 6 months (n = 15), testosterone depot, 100 mg monthly for 3 months (n = 15) or for 6 months (n = 20), nutritional programme (n = 17), oxandrolone and nutritional programme (n = 15) or passive observation (n = 20). Boys in the nutritional programmes received 12 mg/day iron and 6000 IU/week of vitamin A. Outcome measurements were of height, weight, pubertal signs, dietary intake, serum vitamin A, iron, GH and IGF-1. RESULTS: Six months of vitamin A supplementation induced growth acceleration similar to that seen in the oxandrolone- and testosterone-treated children, and significantly greater than in the observation group (9.3 +/- 2.9 vs. 4.0 +/- 0.9 crn/yr, P < 0.001). Whereas in the vitamin A-supplemented group, puberty (increase in testicular volume >/= 12 ml) was induced within 12 months. In all testosterone-treated patients, pubic hair was noted within 3 months and a testicular volume of >/= 12 ml was observed 9-12 months after the initiation of therapy. No pubertal signs were noted in the observation group during this time. CONCLUSIONS: Subnormal vitamin A intake is one of the aetiological factors in delayed pubertal maturation. Supplementation of both vitamin A and iron to normal constitutionally delayed children with subnormal vitamin A intake is as efficacious as hormonal therapy in the induction of growth and puberty.

Adolescent↗
PubMed2003

Small for gestational age: towards 2004.

Children born small for gestational age are a non-homogeneous group and etiology and diagnostic needs vary among subgroups. In view of the knowledge accumulated about immediate and future risk factors for these children it is important to study the etiology and to invest in long-term prevention programs. The aim of this report is to summarize the current knowledge on mechanisms leading to intrauterine growth retardation and to review the intervention procedures.

Child Development↗
PubMed2001

Interrelationship between insulin, leptin and growth hormone in growth hormone-treated children.

OBJECTIVES: The aim of the study was to examine insulin homeostasis during growth hormone (GH) therapy, and to investigate the effect of GH treatment on insulin and leptin concentration in obese children. SUBJECTS: Nineteen obese children (8 with Prader-Willi Syndrome (PWS)) were treated with GH 0.1 IU/kg/day dose for 3 months and were compared with 29 non-treated age and sex matched obese children (9 PWS) and 49 GH treated non-obese short children. Mean age of the children was 10.3+/-1.8 (6.7-13.8) y, with body mass index of 23.6+/-10.4 (11.5-47) kg/m2. RESULTS: Leptin concentration decreased and was correlated inversely with initial leptin value (r2=-0.374, P<0.001) and decreased body mass (r2=0.338, P=0.001). Insulin sensitivity index was not significantly changed during therapy. Leptin decrease after 3 months of GH administration was correlated inversely with the increase in first phase insulin response to intravenous glucose tolerance test (IVGTT) (r2=-0.595, P<0.001). Results of long-term follow-up of treated patients demonstrated a decrease in insulin concentration after cessation of therapy. In GH-treated subjects, the glucose increase in response to glucose load appeared to be higher than in untreated subjects. CONCLUSION: The high insulin response to glucose load seen in GH-treated subjects was appropriate to their glucose concentration and the insulin sensitivity index was unchanged relative to the pretreatment period. Increased insulin dosage in our patients did not induce an increase in leptin concentrations as had been hypothesised.

Anthropometry↗
PubMed2000

Nocturnal integrated gonadotropin concentrations in evaluating pubertal transition in girls.

We assessed the utility of measuring the physiological levels of gonadotropins as a diagnostic tool for pubertal onset in girls. Two methods of gonadotropin measurements were compared: the standard frequent sampling method, in which blood samples were drawn every 20 min, and the multiple integrated sampling method, in which samples were obtained continuously at 30 min intervals by a withdrawal pump. The two methods were examined simultaneously overnight in a group of eight girls at different stages of puberty. The following parameters of both LH and FSH secretion, calculated by PULSAR program, were highly correlated between these methods: area under the curve (AUC), mean levels, mean from smoothed baseline and mean peak height. The diagnostic value of multiple integrated sampling of gonadotropins (performed over 6 h) was then assessed in five prepubertal girls and six girls at early puberty (Tanner stages 2 and 3), in whom peak gonadotropins levels in response to GnRH stimulation test were in the prepubertal range. Several parameters of LH (but none of FSH) were significantly higher (p<0.05) in early pubertal compared to prepubertal girls: AUC (5.61 +/- 2.40 vs 2.39 +/- 1.41), mean levels (0.52 +/- 0.21 vs 0.23 +/- 0.14), smoothed mean level (0.43 +/- 0.18 vs 0.18 +/- 0.11) and peak area (0.27 +/- 0.08 vs 0.11 +/- 0.06). We conclude that the technically simple method of multiple integrated sampling is useful in detecting pubertal transition and is superior to the GnRH-stimulation test. This method can be used in selective cases when the stimulation test yields equivocal results.

Adolescent↗
PubMed1999

Testosterone effect on growth and growth mediators of the GH-IGF-I axis in the liver and epiphyseal growth plate of juvenile rats.

Several studies have suggested that testosterone may have a direct, GH-independent effect on growth. In order to assess possible mechanism(s) whereby testosterone exerts its growth-promoting effect, we evaluated its effect on growth mediators of the GH-IGF-I axis, in both the liver and the epiphyseal growth plate (EGP). Testosterone was administered to peripubertal rats and the responses of mRNA of GH receptor, IGF-I, IGF-I receptor and IGF-binding proteins-1 and -3 (IGFBP-1 and IGFBP-3) as well as circulating IGF-I were evaluated in two time-related models: over 12 h after a single injection (short-term study) and 10 days after continuous administration (long-term study). Rats in the short-term study were castrated and were killed 1, 4, 6 and 12 h post injection. Rats in the long-term study were divided into two groups: castrated vs castrated and hypophysectomized, in order to assess the effect of testosterone in the presence and absence of GH. mRNA levels were determined by RNase protection assay, and serum IGF-I by RIA. Testosterone enhanced weight gain in the rats treated for 10 days, a change that was similar in the presence or absence of GH. This effect was relatively small, however, by comparison with the total weight gained without testosterone. Testosterone had no effect on hepatic IGF-I mRNA abundance but induced a reduction in circulating IGF-I levels, in both the short- and long-term study. Testosterone had no effect on hepatic GH receptor and IGFBP-3 mRNA levels but resulted in a transient, short-term elevation in IGFBP-1 mRNA levels that was maximal 4 h post injection. In the EGP, neither testosterone administration nor hypophysectomy had any effect on IGF-I and IGF-I receptor mRNA levels. However, testosterone increased GH receptor mRNA abundance after 10 days of continuous administration in hypophysectomized rats only. These data suggest that the effect of testosterone on growth (as assessed by weight gain) is small and is not mediated by changes in hepatic gene expression of IGF-I, IGF-I receptor, IGFBP-1, IGFBP-3 or circulating IGF-I. At the EGP, the testosterone effect on linear growth is not mediated through changes in mRNA abundance of IGF-I and IGF-I receptor. The small but significant elevation of GH receptor mRNA levels in hypophysectomized rats may suggest a testosterone-mediated augmentation of a GH effect at the target organ.

Animals↗
PubMed1998

Sertoli cell tumor causing precocious puberty in a girl with Peutz-Jeghers syndrome.

Distinctive ovarian and cervical tumors are associated with Peutz-Jeghers syndrome (PJS). The most common gynecological tumors in this syndrome are adenoma malignum of the uterine cervix and ovarian sex cord tumor, particularly sex cord tumor with annular tubules (SCTAT). Other kinds of ovarian tumors have been rarely reported in association of PJS, including Sertoli cell tumors. We report a case of a 4.5-year-old girl with PJS who presented with isosexual precocious puberty (IPP) due to ovarian lipid-rich Sertoli cell tumor. In addition to estrinizing effect of the tumor, the patient had decidual reaction secondary to tumor-derived progesterone secretion. The literature on gonadal tumors in PJS is reviewed, including one previous report of ovarian lipid-rich Sertoli cell tumor associated with this syndrome.

Child↗
PubMed1997

Evolving growth hormone deficiency in children with a subnormal secretion of growth hormone.

Three growth-retarded children with a normal growth hormone (GH) response to provocative tests, but subnormal 24-hour integrated concentrations of GH and insulin-like growth factor-binding protein 3 (IGF-BP3) are presented. Retesting 3 to 4 years later demonstrated a subnormal GH response to stimulation. The initial subnormal growth rate and IGF-BP3, despite a normal GH response to stimulation, may be secondary to a subnormal integrated concentration of GH.

Child, Preschool↗
PubMed1997

Effect of age on the response to parathyroid hormone.

Serum phosphate (PO4) levels and the tubular threshold for PO4 corrected for glomerular filtration (TP/GF) are age-dependent, being higher in children than in adults. We evaluated the effect of age on the response to infusion of parathyroid hormone(1-34) (PTH) in healthy children (n = 8) and adults (n = 12). In addition, six patients with pseudohypoparathyroidism (PHP) and two with PTH deficiency (hypoparathyroidism [HP]) were also studied. At baseline, TP/GF in normal subjects was inversely correlated with urinary cyclic adenosine monophosphate corrected for glomerular filtration (UcAMP/GF) (P < .0359). After PTH administration in the controls, UcAMP/GF was inversely correlated with TP/GF (P < .0007) and directly correlated with maximal fractional extraction of PO4 (FEP) (P < .0002). The slope of the regression of TP/GF (P < .0076) and FEP (P < .0034) with UcAMP/GF was steeper in children than in adults. Two HP patients had high PTH-stimulated UcAMP/GF levels, but stimulated TP/GF and FEP were not changed commensurate with levels that would expected from the normative data. In six patients with PHP, PTH-stimulated TP/GF was also correlated with peak UcAMP/GF (r = .96, P < .002). PHP patients could be distinguished from normal controls based on the combination of low peak FEP or high TP/GF together with low peak UcAMP/GF. Thus, in normal subjects, the phosphaturic response to PTH is correlated with the increase in urinary cAMP and is age-dependent, with a greater decrease of TP/GF in children than in adults.

Adolescent↗
PubMed1997

Final height after growth hormone therapy in short children: correlation with siblings' height.

Sixteen prepubertal children (10 males, 6 females) were treated with growth hormone (GH) 0.75 U/kg/week for 4-5 years until final height was attained. Before initiation of GH therapy height was below 2 SDS for age and gender, growth velocity was <4.5 cm/year, bone age was more than 2 SD below the mean for age, and the GH response to provocative tests was more than 10 microg/l. The final height of 9 patients exceeded their predicted and target heights. The final height of the treated patients was highly correlated with their siblings' heights (r = 0.806, p < 0.001) and to a lesser degree with the target or the predicted height (r = 0.401, p = 0.124 and r = 0.465, p = 0.06, respectively). It is concluded that the secular trend should be taken into consideration when evaluating the success of GH therapy.

Body Height↗
PubMed1996

Growth of short children during and after discontinuation of growth hormone therapy.

We have attempted to evaluate the relationship between spontaneous growth hormone (GH) secretion and the response to GH therapy as well as the effect of discontinuation of GH therapy on further growth. The 24-h integrated concentration of GH (ICGH) was determined in 150 short children (< 2 SD for age) with a GH response to clonidine stimulation of more than 10 mcg/L. The patients were treated with GH for 4 yr and were observed for 1 yr following cessation of GH treatment. Twenty-two out of 52 patients who had an ICGH of less than 3.2 mcg/L (group LICGH) and 28 out of 60 patients who had an ICGH of more than 3.2 mcg/L (group NICGH) were followed without GH therapy. Only patients who remained prepubertal throughout the study were included in the analysis. The growth response of the LICGH to GH was better than that of the NICGH children. Patients regained normal growth velocity 6-12 months after discontinuation of GH therapy. Three children of the LICGH subsequently developed classic GH deficiency. These studies demonstrate that short-term GH therapy can improve the growth channel. Children with a low ICGH grow better on GH than children with a normal ICGH. Children with a low ICGH need continued observation and retesting when growth velocity is low.

Body Height↗
PubMed1995

Urinary cyclic adenosine 3',5'-monophosphate response in McCune-Albright syndrome: clinical evidence for altered renal adenylate cyclase activity.

The recent finding of an activating mutation in the Gs alpha protein, the protein that couples receptors to stimulation of adenylate cyclase, from endocrine and nonendocrine tissues of patients with McCune-Albright syndrome (MAS) suggests that alterations in adenylate cyclase activity may account for the clinical abnormalities in these patients. Many patients with MAS have hypophosphatemia. This may result from the presence of the activating Gs alpha mutation in proximal renal tubules or the elaboration of a phosphaturic factor from fibrous dysplasia. We, therefore, sought to characterize renal cAMP generation and phosphate handling in MAS patients. Intravenous infusion of PTH is a classic clinical test used to evaluate hormonal responsiveness of renal proximal tubule adenylate cyclase and examine PTH-dependent phosphate clearance. We performed PTH infusion in 6 MAS patients, 10 normal subjects, and 6 patients with pseudohypoparathyroidism (PHP). The basal urinary cAMP (UcAMP) level in the MAS group [5.5 +/- 2.6 nmol/dL glomerular filtration (GF)] was elevated (P < 0.05) compared to those in both normal subjects (3.2 +/- 1.2 nmol/dL GF) and patients with PHP (1.9 +/- 0.6 nmol/dL GF). However, PTH-stimulated peak UcAMP (15.0 +/- 7.0 nmol/dL GF) and the peak/basal UcAMP ratio (3.1 +/- 1.7) in MAS were significantly lower than the respective values in normal subjects (30.8 +/- 16.9 nmol/dL GF and 9.3 +/- 2.9; P < 0.05 for both) and were statistically similar to the blunted levels in PHP (respectively, 3.1 +/- 1.5 nmol/dL GF and 2.0 +/- 1.7). By contrast, the PTH-induced phosphaturic response in MAS patients was similar to that in the normal subjects. Our study provides clinical evidence that MAS patients have altered renal adenylate cyclase activity, manifested by an elevated basal UcAMP, but a blunted UcAMP response to PTH stimulation. These observations are presumably due to a mutation in the Gs alpha protein in the renal tubules. Despite the blunted UcAMP excretion, the phosphaturic response to PTH in MAS patients is intact.

Adenylyl Cyclases↗
PubMed1994

Effect of long-term growth hormone therapy on bone age and pubertal maturation in boys with and without classic growth hormone deficiency.

We evaluated the effect of growth hormone (GH) therapy on bone age, pubertal maturation and predicted adult height in two groups of boys treated for 4 years: 40 growth hormone-deficient boys who had growth hormone response to provocative stimulation < 10 micrograms/L (GHD group) and 43 boys whose stimulated growth hormone > or = 10 micrograms/L (group with neurosecretory dysfunction (NSD)). All patients had a subnormal integrated concentration of growth hormone < or = 3.2 micrograms/L, height < -2 SD, growth velocity < 4.5 cm/yr, and bone age < or = -2 SD for chronologic age. Patients were treated with recombinant growth hormone, 0.1 mg/kg per dose given three times a week. The pretreatment height SD of the GHD group (-3.6 +/- 1.0) was less than that of the NSD group (-2.7 +/- 0.7; p < 0.001). After 4 years of therapy, both groups had catch-up growth (GHD group to -2.0 +/- 1.3 height SD (n = 35), and NSD group to -1.4 +/- 0.7 height SD (n = 32)); the rate of height SD gain was better in patients with GHD (p < 0.01). The response to growth hormone was inversely related to pretreatment chronologic age (p < 0.001). The Tanner-Whitehouse II predicted adult height improved for both groups: +9.3 +/- 7.7 cm in the GHD group, giving an adult height SD of -0.9 +/- 1.0, and +5.4 +/- 5.5 cm in patients with NSD, for an adult height SD if -0.8 +/- 0.7. Testosterone levels became higher in the NSD group after 2 years and remained higher at year 4. We conclude that patients respond favorably to growth hormone therapy and in a manner similar to patients with GHD. Initiation of therapy at a younger age gives a greater improvement in gained height and predicted adult height.

Age Determination by Skeleton↗
PubMed1993

Ictal cortical blindness: a case report and review of the literature.

Acute cortical blindness as an ictal phenomenon has seldom been reported in the literature. The authors describe a seven-year-old boy who experienced several episodes of complete visual loss, accompanied by gastro-intestinal symptoms and a sensation of fright, but with preservation of consciousness. These episodes ended abruptly with visual recovery and no postictal phenomena. CT brain scan was normal and interictal EEG showed bi-occipital epileptiform activity. This case fits the definition of true ictal blindness. A literature review of seizure-related blindness is presented.

Blindness↗
PubMed1990

Occurrence of cerebrohepatorenal (Zellweger) syndrome in the Karaite community in Israel: a genetic hypothesis.

Two infants with the cerebrohepatorenal (Zellweger) syndrome in Karaite families are described. This syndrome has an autosomal recessive mode of inheritance with an estimated incidence of between 1:25,000 and 1:100,000 live births. In addition to a previous report of the syndrome in a Karaite family, this report raises the possibility of a high incidence of Zellweger Syndrome among the Karaites in Israel.

Adult↗
PubMed1990

Adult respiratory distress syndrome: roles of leukotriene C4 and platelet activating factor.

The relationship between leukotriene C4 (LTC4), platelet activating factor (PAF), and adult respiratory distress syndrome (ARDS) was studied in nine patients and 84 control subjects. A leukocyte adherence inhibition (LAI) assay induced by each of the ligands was used to monitor the subjects for 3 consecutive days or until clinical recovery was noted. LAI was considered to be positive if the nonadherence index (NAI) was greater than 30 for LTC4 or greater than 20 for PAF. LAI was negative in all healthy subjects using both ligands. LTC4-induced LAI was positive in all nine ARDS patients and reverted to negative after recovery from the syndrome, while three (33.3%) of nine patients responded to PAF. In contrast, of the 84 control subjects, LAI was induced by LTC4 in only three (3.3%) and by PAF in five (5.9%). The mean NAI (52.2 +/- 18) of LTC4-induced LAI in ARDS patients was significantly (p less than .05) higher when compared with the control group (-5 +/- 6.4), whereas that of PAF-induced LAI was less than 20 in both groups, indicating that LTC4 is a more specific ligand than PAF. All three patients in whom ARDS was caused by sepsis responded to both LTC4 and PAF, but results of specific receptor-antagonist experiments indicated that each compound acted independently. The mean NAI for LTC4 (58.5 +/- 10) and PAF (49.1 +/- 12) in patients with septic ARDS were significantly (p less than .05) higher when compared with those of patients with sepsis alone (0.5 +/- 9.9 and 4.4 +/- 17, respectively).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗