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Biomedical subjects

M Phillip

Publications and source records attributed to M Phillip.

At least 55 records · Page 3Linked to original sources
PubMed1999

Zinc supplementation increases the level of serum insulin-like growth factor-I but does not promote growth in infants with nonorganic failure to thrive.

We investigated in a randomized double-blind placebo-controlled study the effects of zinc supplementation (2 mg/kg/day) for 12 weeks on growth, serum insulin-like growth factor-I (IGF-I) and insulin-like factor binding protein-3 (IGFBP-3) on 3- to 9-month-old infants with nonorganic failure to thrive (NOFTT). 25 infants completed the study, 14 received zinc supplementation (group A), and 11 received placebo (group B). The control group for baseline measurements was composed of 10 age-matched normal growing infants. There were no significant changes in weight for age, length for age, or weight for length during the entire study period in either group A or B. Serum IGF-I levels at baseline were similar in all the groups. After 12 weeks of therapy, serum IFG-I levels increased significantly only in the zinc-supplemented group, from 40.3 +/- 7 ng/ml at baseline to 65 +/- 8 ng/ml (p < 0.05). There was a marked difference in serum IGF-I levels between the zinc-supplemented group and the placebo group after 12 weeks: 65 +/- 8 vs. 49.4 +/- 5 ng/ml (p = 0.058, 95% CI of difference 9.88-21.31). No change was demonstrated in serum IGFBP-3 levels in either study group. We conclude that although zinc supplementation increased serum IGF-I levels, it did not improve the growth parameters of infants with NOFTT.

Dietary Supplements↗
PubMed1999

Testosterone stimulates insulin-like growth factor-I and insulin-like growth factor-I-receptor gene expression in the mandibular condyle--a model of endochondral ossification.

Puberty is associated with an increase in the plasma concentration of sex steroids, GH, and insulin-like growth factor-I (IGF-I). Gonadal steroid hormones are important for the normal pubertal growth spurt and skeletal growth. The mechanism by which gonadal steroids induce skeletal growth is still not fully understood. To better understand the direct effect sex steroids have on bone growth, we studied an isolated organ culture system of the mandibular condyle, derived from 3.5-5.5-week-old male and female mice. We found that testosterone 10(-6) M, but not estradiol, stimulated thymidine incorporation into the DNA of male-derived condyle. Three days of testosterone treatment doubled the condyle size and increased the chondroprogenitor zone, while maintaining the normal gradient of the developing chondrocytes. Immunohistochemistry and in situ hybridization techniques showed that testosterone stimulated IGF-I and IGF-I-R and their messenger RNAs (mRNAs) mainly in the mature chondrocyte layer. Immunoneutralization of IGF-I in the testosterone-treated condyle caused the disappearance of the chondroblast and young chondrocyte layers, though the progenitor cell layer remained almost unaffected. Overtreatment with testosterone (dose or duration) accelerated condylar ossification. In the presence of testosterone 10(-5) M (high dose), calcification "climbs" up to the chondroprogenitor zone, and most of the condylar chondrocytes are replaced by bone tissue. Similar changes occurred after 7 days of testosterone treatment (long duration) with 10(-6) M. In conclusion, testosterone stimulates growth and local production of IGF-I and IGF-I-R in chondrocyte cell layers of an isolated organ culture of mice mandibular condyle. Part of the effect testosterone has on condylar growth is mediated by IGF-I.

Animals↗
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

Growth hormone receptor antagonism prevents early renal changes in nonobese diabetic mice.

The growth hormone (GH)/insulin-like growth factor (IGF) axis is involved in diabetic renal disease. The role of a specific GH receptor (GHR) antagonist in the development of early renal changes in nonobese diabetic (NOD) mice was investigated. Female diabetic (nonketotic) NOD mice treated with a polyethylene glycol-treated GHR antagonist (2 mg/kg, every other day) (DA group) or saline (D group) and their nonhyperglycemic age-matched littermates (control animals) were euthanized 3 wk after the onset of diabetes. Body weights at euthanasia were similar among the groups. Serum GH levels were markedly elevated, and serum IGF-I levels were significantly decreased in D and DA animals, compared with controls. The increases in kidney weights and glomerular volumes observed for the D group were absent in the DA group. Albuminuria was increased in the D group but was normalized in the DA group. Extractable renal IGF-I protein levels were increased in the D group but were partially normalized in the DA group. Renal IGF-binding protein 1 mRNA levels were increased in the D group but returned to almost normal levels in the DA animals. Kidney IGF-I and GHR mRNA levels were decreased in both the D and DA groups. Renal GH-binding protein mRNA levels remained unchanged in both diabetic groups. GHR antagonism had a blunting effect on renal/glomerular hypertrophy and albuminuria in diabetic NOD mice. These salutary effects were associated with concomitant inhibition of increased renal IGF-I protein levels and were obtained without affecting either somatic growth or circulating GH and IGF-I levels. Therefore, modulation of GH effects may have beneficial therapeutic implications in diabetic nephropathy.

Animals↗
PubMed1998

Increase of serum lipoprotein (a) levels during growth hormone therapy in normal short children.

UNLABELLED: We studied the effect of growth hormone (GH) therapy on serum lipoprotein levels and the atherogenic index in short children without GH deficiency. Fasting blood samples were collected from ten (eight males) normal, short, prepubertal children, aged 6-12 years, before, during a 1-year course of GH therapy (0.1 IU/Kg/day), and 3 months after the cessation of GH administration. An increase in serum lipoprotein(a) [Lp(a)] levels of (mean% +/- SEM) 43 +/- 14, 58 +/- 18, 61 +/- 17 above the baseline levels was noted at 3 months (P < 0.05), 6 months (P < 0.01), and 1-year (P < 0.01) respectively after the beginning of GH administration. (ANOVA, P < 0.01). An inverse relationship between baseline serum Lp(a) concentrations and the percentage increment in Lp(a) after 9 months of GH therapy (r = -0.65, P < 0.05) was observed. GH therapy over a period of 1 year had no effect on plasma cholesterol, triglycerides, low density lipoprotein-cholesterol (LDL-C), high density lipoprotein cholesterol [HDL-C] concentrations and the atherogenic index. Three months after the cessation of GH therapy, serum Lp(a) levels were not significantly different from the pre-treatment values. CONCLUSIONS: Serum Lp(a) concentrations remained above pretreatment values during a 1-year period of GH treatment in short children without GH deficiency and declined shortly after cessation of therapy. Since GH therapy for short children without GH deficiency usually continues for several years, we suggest that serum Lp(a) levels should be determined and followed regularly in such children under prolonged GH therapy.

Analysis of Variance↗
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↗
PubMed1998

Clinical presentation and outcome in primary familial hypomagnesaemia.

The clinical presentation and long term outcome (mean follow up eight years, range 0.25 to 21) of 15 patients with autosomal recessive primary familial hypomagnesaemia is described. The most common (67%) presenting events were generalised hypocalcaemic-hypomagnesaemic seizures at a mean (SD) age of 4.9 (2.5) weeks. Thirteen infants, treated soon after diagnosis with high dose enteral magnesium developed normally. Their serum calcium returned to normal concentrations but serum magnesium could not be maintained at normal concentrations (0.53 (0.12 SD) mmol/l; normal > 0.62). Delay in establishing a diagnosis led to a convulsive disorder with permanent neurological impairment in two infants. Reported complications of prolonged hypomagnesaemia such as renal stones, hypertension, arrhythmias, sudden death, or dyslipidaemia were not observed.

Consanguinity↗
PubMed1998

Serum insulin-like growth factors I and II are not affected by undernutrition in children with nonorganic failure to thrive.

The aim of our study was to determine the serum levels of IGF-I, IGF-II, and their binding proteins IGFBP-1 and IGFBP-3 in young children 3 months to 2 years of age with nonorganic failure to thrive (NOFTT). 29 children with NOFTT and 32 normal controls were recruited and studied for auxologic and hormonal parameters. The NOFTT group had significantly higher serum concentrations of IGFBP-1 than the control group: 57.7+/-18 vs. 48+/-19 microg/l (p < 0.05). IGF-I and IGF-II serum levels were highly correlated to serum IGFBP-3 but there were no differences in the serum IGF-I, IGF-II and IGFBP-3 levels between the groups. We conclude that IGF-I, IGF-II, and IGFBP-3 are not useful for the evaluation of nutritional status in children, under the age of 2 years, with NOFTT.

Child, Preschool↗
PubMed1998

Normal melatonin levels in patients with fibromyalgia syndrome.

OBJECTIVE: To assess urine levels of melatonin measured by 6-sulphatoxymelatonin (aMT6s) in patients with fibromyalgia (FM). METHODS: Nocturnal aMT6s urine levels were measured by ELISA, in a sample of urine collected from 10 PM to 7 AM from 39 female patients with FM and 39 age matched healthy female controls. All subjects were interviewed and assessed for nonarticular tenderness, FM symptoms, quality of life, and physical functioning. RESULTS: Nocturnal aMT6s levels of patients with FM were not statistically different from those of controls: 16.7+/-9.2 vs 16.0+/-11.3 microg, respectively. No association was observed between aMT6s levels of patients with FM and disease duration, reproductive status, sleep and mood disturbances. CONCLUSION: Nocturnal urine aMT6s levels were similar in patients with FM and controls. Studies are needed to elucidate the possible role of melatonin in FM and should include larger samples of newly diagnosed untreated patients with FM.

Adult↗
PubMed1997

Renal hypertrophy in hyperglycemic non-obese diabetic mice is associated with persistent renal accumulation of insulin-like growth factor I.

The non-obese diabetic mouse is a model of spontaneous insulin-dependent diabetes as a result of autoimmune destruction of pancreatic beta cells, similar to the disease seen in human Type I diabetes. This mouse strain develops glomerular lesions reminiscent of those seen in human disease. The study presented here investigated the changes in renal insulin-like growth factor (IGF) system in hyperglycemic non-obese diabetic mice. Female non-obese diabetic mice and their age- and sex-matched controls were euthanized 4 days, 2 wk, and 4 wk after the onset of glycosuria. Kidney weight increased in diabetic mice, beginning at 2 wk after the onset of glycosuria. This renal hypertrophy was associated with an increase in renal extractable IGF-I protein. However, a decrease in IGF-I mRNA was observed at the same time. Serum IGF-I levels remained stable after 2 wk of diabetes and decreased at 1 month. No change was detected in renal IGF-I receptor mRNA levels. Renal cortical IGF binding protein (IGFBP)-1 mRNA levels were increased. Ligand blot analysis revealed a significant increase in serum and renal 30-kd IGFBP and a decrease in serum and kidney IGFBP-3 and IGFBP-4 at 30 days of diabetes. Insulin therapy prevented the increases in kidney weight, renal IGF-I, and 30-kd IGFBP, but did not reverse the decreased serum IGF-I levels observed at 1 month of diabetes. In summary, renal hypertrophy in non-obese diabetic mice is associated with a persistent accumulation of renal IGF-I and, IGFBP-1. These changes were partially reversed with insulin therapy, which did not correct the hyperglycemia, suggesting an important role for insulin deficiency in mediating these changes in the IGF system. These findings suggest that the IGF system may play a potential role in the development of diabetic nephropathy.

Animals↗
PubMed1997

The effect of 2,3 dimercaptosuccinic acid in the treatment of lead poisoning in adults.

Four patients, aged 22-60, belonging to a single family that had been exposed to lead-contaminated food for an unknown period, and nine workers, aged 20-65, who had been exposed to air-borne lead for 6-8 years, were evaluated for lead poisoning in our centres. Blood lead levels were 3.57 +/- 0.39 micromol/L (mean +/- SD) in the family members and 3.46 +/- 0.43 micromol/L (mean +/- SD) in the group of workers. 2,3 dimercaptosuccinic acid (DMSA) therapy was instituted in the four family members while the nine workers were closely monitored after being removed from the contaminated environment without receiving any chelation therapy. DMSA therapy given for the duration of 19 days reduced the blood lead levels to 0.63 +/- 0.44 micromol/L (mean +/- SD), P<0.01, in the four family members. No significant change was observed in the untreated group. The exposure time in the untreated group was probably longer than that in the treated group. Following long-term exposure most of the lead in the body is found in the bones and therefore not easily removed by chelation therapy. No side-effects were reported in the treated group and no rebound elevation of blood lead levels was observed during the therapy period or during the 12-week follow-up period following cessation of therapy. We conclude that 19 days of chelation therapy with DMSA in adults with moderate to severe lead poisoning is effective and safe.

Administration, Oral↗
PubMed1996

Effect of six months of growth hormone therapy, followed by treatment withdrawal in short children with normal quantitative indexes of growth hormone secretion.

Eight short patients with normal 24-hour integrated concentration of growth hormone by continuous withdrawal (IC-GH) received 6 months of GH therapy, followed by 6 months off. GH therapy increased growth rate (+2.9 cm/yr), repeated IC-GH (sixfold), and IGF-1 concentration (twofold). Posttreatment growth reverted to the pretreatment rate. Thus increased growth rate and IGF-1 concentration is associated with supraphysiologic IC-GH after injection.

Adolescent↗
PubMed1996

The relationship of growth rate, plasma growth hormone (GH) concentration, and GH-binding protein.

Growth hormone (GH)-binding protein (GHBP) and GH secretion are potential mediators of linear growth in children. To study the relationship between these variables, we measured GHBP activity, peak stimulated GH (PKGH), and 24-hour integrated GH concentration (ICGH) in 76 children referred for evaluation of growth. Linear growth was expressed as an age- and sex-specific growth rate standard deviation score (GRSD), which was calculated from sequential height measurements in the 6-month period immediately before GH testing. Using multiple regression models, we found that the relationship between GHBP and growth (GRSD) depended on height (height standard deviation [HGTSD] expressed as an age- and sex-specific z score) controlling for ICGH or PKGH. In further analysis of this relationship, we divided the subjects by HGTSD in subsequent analyses. In 19 children of normal stature (HGTSD > -2), GRSD increased with GH concentration (measured both as PKGH and ICGH: P <.013,R2 = .56) but decreased with higher levels of GHBP (P < .005,R2 = .62). In contrast, for 57 subjects with severe short stature (HGTSD < or = -2), GRSD could not be predicted from GHBP, GH secretion, HGTSD, or interaction involving these variables. These data suggest the hypothesis that under normal conditions, GHBP and GH level may be important predictors of growth rate in children.

Adolescent↗
PubMed1996

Short-term growth hormone therapy increases serum lipoprotein (a) levels in normal short children without growth hormone deficiency.

We investigated the short-term effect of GH (0.1 IU/kg/day) on serum lipoprotein (a) [Lp(a)] in 8 normal short children aged 6-12 years. GH increased serum Lp(a) concentrations in all the children studied. An increase to 107 +/- 5, 161.6 +/- 14.7 and 152.5 +/- 18.5% (mean +/- SE) of baseline levels was observed after 2 (p = NS), 6 (p < 0.01) and 12 weeks (p < 0.05), respectively. Our results suggest that GH therapy may pose a significant influence on Lp(a) serum levels in non-GH-deficient short children.

Body Height↗