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Biomedical subjects

Z Zadik

Publications and source records attributed to Z Zadik.

At least 19 recordsLinked to original sources
PubMed2005

Differences in infantile growth patterns in Turner syndrome girls with and without spontaneous puberty.

OBJECTIVE: The role of prepubertal estrogen in child growth was modeled using Turner's syndrome, comparing growth patterns of girls who later did or did not enter puberty spontaneously. The hypothesis was that TS patients with normal prepubertal estrogen levels would have a different growth pattern from those with subnormal estrogen levels. STUDY DESIGN: Growth data from 78 full-term patients with Turner's syndrome were collected retrospectively. 24/78 later developed spontaneous puberty, (+Pub), and their growth data were compared to TS patients without spontaneous puberty (-Pub). A nonlinear mixed model was fitted using the bi-exponential model. RESULTS: The growth velocity difference between the -Pub and +Pub groups suggests an early infantile growth advantage in the -Pub group, which disappears before the end of the first year of life; growth velocity remains similar (+/- 1 cm/y) for the next 6 years and declines at age 7-8 years in the +Pub group faster than it does in the -Pub group. Bi-exponential analysis showed that both the 1st (restrictive) and 2nd exponent (forward) were different (p = 0.0003). CONCLUSIONS: Comparison of girls with or without spontaneous puberty suggests a role for estrogen in child growth. Estrogens restrict infantile growth, as well as growth during the mid-childhood spurt.

Adolescent↗
PubMed2004

From bone biology to bone analysis.

Bone development is one of the key processes characterizing childhood and adolescence. Understanding this process is not only important for physicians treating pediatric bone disorders, but also for clinicians and researchers dealing with postmenopausal and senile osteoporosis. Bone densitometry has great potential to enhance our understanding of bone development. The usefulness of densitometry in children and adolescents would be increased if the physiological mechanisms and structural features of bone were given more consideration in the design and interpretation of densitometric studies. This review gives an overview on the most relevant techniques of quantitative noninvasive bone analysis. Furthermore it describes the relationship between bone biology, selected surrogates describing the biological processes and the possibilities of measuring these surrogates specifically and precisely by the different devices. The overall recommendation for researchers in this field is to describe firstly the biological process to be analyzed (bone growth in length, remodeling or modeling, or all together), secondly the bone parameter which describes this process, and thirdly the reason for selecting a special device.

Absorptiometry, Photon↗
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

Hypopituitaric patients with corticotropin insufficiency show marked impairment of the cortisol response to ACTH (1-24) independently of the duration of the disease.

It is widely accepted that the classical dose of 250.0 microg ACTH (1-24) (tetracosactin) is clearly supra-maximal while 1.0 and 0.03 microg have been shown as the maximal and the lowest stimulatory ACTH doses for cortisol (F) secretion in normal young subjects. Testing with low ACTH dose would better evaluate adrenal sensitivity to corticotropin. The aims of the present study were: a) to clarify the adrenal sensitivity to ACTH in patients with different duration of corticotroph insufficiency by testing with low and very low tetracosactin doses; and b) to evaluate diagnostic implication regarding the ability of ACTH tests to distinguish patients with corticotroph insufficiency from normal subjects. In 24 hypopituitaric patients (HYPOPIT, 15 male and 9 female, age 22-50 yr, BMI: 22-26 kg/m2) with corticotrophin deficiency we studied the F, DHEA and aldosterone (A) responses to challenges with low ACTH doses (0.06 or 0.5 microg iv at 0 min) followed by 250 microg iv (at +60 min). The results in HYPOPIT were compared with those recorded in 12 normal controls (NS, 6 male and 6 female, age 22-34 yr, BMI: 20-25 kg/m2). Basal F and DHEA levels in HYPOPIT were lower than in NS, while A levels were similar in both groups. The F responses to ACTH in HYPOPIT were dose-independent and markedly lower (p < 0.0001) than in NS. After the 0.06 and 0.5 microg ACTH dose, 16% of HYPOPIT patients showed AF peak within the range of normal response. No HYPOPIT showed AF peak within the normal range after 250 microg ACTH. The DHEA responses to ACTH in HYPOPIT were dose-independent and markedly lower than in NS (p < 0.0001). Overlap between individual DHEA responses in HYPOPIT and NS was present after 0.06 microg and 0.5 microg but not after 250 microg tetracosactin. The A responses in HYPOPIT were dose-dependent and overlapped with those in NS. The adrenal responses to ACTH in HYPOPIT were not associated with the duration of the disease. In conclusion, the present study shows that the mean F and DHEA but not the A responses to ACTH (1-24) are markedly impaired in hypopituitaric patients with corticotroph insufficiency independently of the duration of the disease. The impaired F and DHEA response to ACTH is also independent of the dose, suggesting the existence of relatively enhanced sensitivity of the fasciculata and reticularis adrenal zone to ACTH but meantime remarkable impairment of the adrenal function due to corticotrophin deficiency. In the present study, testing with submaximal ACTH doses did not distinguish patients with secondary adrenal insufficiency from normal subjects.

Adrenal Insufficiency↗
PubMed2003

Maternal nutrition, fetal weight, body composition and disease in later life.

Nutritional and hormonal milieu in utero affect fetal growth. Both parties involved have an independent chance, for the occurrence of a developmental error at any stage of their constant developing system. Studies suggest that pregnancy outcome is associated with fetal demand for nutrients and the materno-placental capacity to meet that demand. Failure of the materno-placental supply line to satisfy fetal nutrient requirements results in a range of fetal adaptations and developmental changes, and may lead to permanent alterations in the body's structure and metabolism, and thereby to cardiovascular and metabolic disease in adult life. Changes in the in-utero homeostasis may lead to programming of endocrine and metabolic systems so that feedback systems and reactions are permanently changed. At the present stage, short- and long-term hazards of intra-uterine growth retardation (IUGR) have been identified, but preventive strategies are still lacking. It is unlikely that a single factor will reduce a multi-causal outcome like IUGR. Appropriate population-specific interventions should be a priority.

Adult↗
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

Final height in young women with Turner syndrome after GH therapy: an open controlled study.

GH therapy has been applied to patients with Turner syndrome for over a decade, but small sample size, delayed initiation of therapy into adolescent age and comparison with historical control subjects limit the usefulness of these studies for appraisal of the effect of GH on final adult height. We report 49 young women with Turner syndrome who completed a clinical trial in an open, non-randomized, age-matched controlled study of GH, given as daily s.c. injections at a weekly dose of 8.2 mg/m(2) for 1.9-7.5 years. Final height was defined as the measurement taken 2 years or more after height velocity declined below 2 cm/year and after a bone age of 15 'years'. The gain in height was evaluated in three ways. The mean final height gain, compared with the control group, was 4.4 cm. When corrected for the projected height at inception of therapy, the mean gained height was 5.3 cm above the control group. Shorter girls showed better response to GH then did taller girls. After correcting for parental height, the mean gain was 4.7 cm. The adult height of the GH-treated Turner women was significantly correlated with the target height, whereas no such correlation was obtained for control untreated women. Furthermore, no correlation was observed between height gain and the age or duration of GH therapy, or the age of inception of estrogen replacement therapy. It is concluded that GH therapy augments final height of girls with Turner syndrome by a mean 4.4-5.3 cm, depending on the method of evaluation, and that shorter girls may be preferred candidates for such therapy. GH therapy can be initiated after age 10 years and there is no reason to delay estrogen therapy beyond the age of 12. Indirect evidence suggests that high-dose GH therapy may surmount a pathophysiological resistance in the GH-IGF-I axis.

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↗
PubMed1999

Short stature.

Explore the source record for details and available documents.

Algorithms↗
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↗
PubMed1998

Excessive dietary protein and suboptimal caloric intake have a negative effect on the growth of children with chronic renal disease before and during growth hormone therapy.

Although diet and nutrition are an integral part of the management of individuals with chronic renal failure (CRF), little has been written on the effect of nutrition on the growth response to growth hormone (GH) in CRF. We studied the GH axis and nutritional status of 31 prepubertal children aged 8.7 +/- 0.5 years with a height standard deviation score (SDS) of -3.2 +/- 0.2 (mean +/- SEM) with CRF. Sixteen CRF patients on hemodialysis and 15 on peritoneal dialysis were studied. Forty-four age-matched normal short children without GH deficiency served as controls. Spontaneous 12-hour GH and stimulated GH values were significantly higher and GH binding protein (GHBP) was significantly lower in the CRF patients than in the normal short children. Both before the initiation of GH therapy and after the first year of treatment, the growth velocity (SDS) was inversely correlated with dietary protein intake and positively correlated with caloric intake. GH was administered at a dosage of 28 and 21 IU/m2/wk to the CRF group and the normal short children, respectively, divided into seven daily doses. The growth response of the normal short children was significantly greater than that of the CRF patients. GH therapy induced a smaller increment in GHBP and IGF-I in the CRF patients versus the normal short children (8.8 +/- 2.2 and 10.2 +/- 2.7 v 24.8 +/- 1.3 and 27.6 +/- 2.5 nmol/L, respectively, P < .01). The 1-year growth velocity of the CRF children was most closely correlated with dietary protein and caloric intake. The nutritional status of CRF patients is concluded to be a major factor in growth both before and during GH therapy.

Alkaline Phosphatase↗
PubMed1998

Once versus twice daily injections of growth hormone in children with idiopathic short stature.

The aim of this study was to compare the growth response of 22 short pre-pubertal children without growth hormone deficiency, treated with a single daily growth hormone injection (group A), to the growth response of 27 similar children, treated with the same daily dose divided into 2 subcutaneous injections per day (group B), for 1 y, in a randomized study. GH treatment significantly promoted growth parameters, height standard deviation score and height velocity standard deviation score in both groups. Serum insulin-like growth factor I was also increased. There were no significant differences in growth response, serum IGF-I levels, or the advance in bone age between the two study groups after 1 y of GH therapy. We conclude that twice daily s.c. growth hormone injections provide no advantages over once daily injection of the same dose in promoting the linear growth of short children without growth hormone deficiency.

Age Determination by Skeleton↗
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

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↗