Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P02794 (ferritin)
 17,525 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Endocrine abnormalities in patients with chronic renal failure are well documented. The present study aimed to assess the influence of long-term erythropoietin (EPO) therapy on endocrine abnormalities in haemodialyzed patients. Two groups of haemodialyzed patients, each of which comprised 17 subjects, were examined. The first one treated by EPO (EPO group) while the second one did not receive this hormone (NO-EPO group). A complete biochemical and hormonal check-up was performed before and at the 3, 6, 9 and 12 months of the study period. Normal values for the estimated parameters were obtained in appropriately selected sex and age-matched healthy subjects. After EPO therapy an increase of the haematocrit value from 21.8 +/- 0.9% to 32.6 +/- 0.9% was observed which was accompanied by a significant decline of plasma ferritin and saturation of transferrin. In patients of the NO-EPO group a significant although less marked rise of the haematocrit value (21.4 +/- 0.4% to 24.2 +/- 0.6%) was also noticed. EPO therapy did not change electrolytes (Na, K, Ca, inorganic phosphate), osteocalcin, creatinine, glucose and alkaline phosphatase plasma levels as well as plasma concentrations of calcium related hormones (PTH, calcitonin, 1.25(OH)2D3) and vasopressin (AVP). EPO treatment induced a significant decline of somatotropin (HGH), prolactin (PRO), follitropin (FSH), lutropin (LH), ACTH, cortisol, plasma renin activity, aldosterone, insulin (IRI), glucagon (IR-G), pancreatic polypeptide (PP) and gastrin plasma levels and an increase of plasma estradiol, testosterone and atrial natriuretic peptide (ANP). These EPO induced endocrine alterations were restricted mostly to the first 6 months of EPO administration.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Influence of long-term erythropoietin therapy on endocrine abnormalities in haemodialyzed patients. 145 6

We studied pituitary-gonadal function in 11 male and 5 female patients, aged 12-30 yr, with severe beta-thalassemia and chronic iron overload. All had normal basal serum cortisol, T4, and PRL concentrations and normal serum cortisol and GH responses to insulin-induced hypoglycemia and TSH responses to TRH. Of the 11 male patients (all over 17 yr of age), only 3 attained full pubertal development and 4 had subnormal serum LH and FSH responses to GnRH. As a group, their mean basal serum testosterone (T) level was low [11.7 +/- 4.9 (+/- SE) nmol/L; normal, 10-40 nmol/L], and 9 of the 11 male patients responded to hCG with a rise in serum T. Two of the 3 female patients over 17 yr of age were prepubertal with undetectable serum estradiol (E2) levels and absent serum LH and FSH responses to GnRH; the other female patient had regular menstrual cycles and normal serum E2 levels and LH and FSH responses to GnRH. Six of the prepubertal patients (4 males and 2 females, aged 17-30 yr) were studied serially for 3 yr after the start of chelation therapy. Despite a fall of median serum ferritin from 11,910 to 1,303 pmol/L, there was no progression of puberty, and their basal and GnRH-stimulated serum LH and FSH and serum T or E2 levels did not change. Three of these patients (1 male and 2 female) then received pulsatile sc GnRH therapy in addition to chelation therapy for 6 months with no improvement. We conclude that chronic iron overload in patients with severe thalassemia leads to variable degrees of hypogonadotropic hypogonadism, which do not respond to chelation therapy given late in the course of the disease. The hypogonadism in most patients was due to pituitary hyporesponsiveness to GnRH.
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PMID:Hypogonadotropic hypogonadism in severe beta-thalassemia: effect of chelation and pulsatile gonadotropin-releasing hormone therapy. 249 34

Endocrine function was evaluated in 20 prepubertal patients with homozygous beta-thalassemia treated with frequent transfusions and long term iron chelation therapy. FSH, LH, PRL, and TSH secretion were evaluated by LRH and TRH testing and L-dopa and ACTH were used to assess GH and adrenocortical reserve. No statistically significant differences were found between FSH, LH, PRL, GH, and cortisol secretion in the patients and in normal subjects. There was a relatively high incidence (35%) of primary thyroid impairment since 1 patient had primary hypothyroidism and 6 others had evidence of subclinical hypothyroidism as manifested by increased TSH responses to TRH. However, no statistically significant correlations were found between either serum ferritin levels, total blood transfusions received, and thyroid function.
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PMID:Endocrine functioning in multitransfused prepubertal patients with homozygous beta-thalassemia. 632 34

Rapid freeze-substitution fixation was employed in immunocytochemical studies on the localization of LH and FSH in the typical gonadotrophs of the anterior pituitary in the untreated male rat; a modification of a recently described ferritin antibody method (Inoue et al. 1982) was used in these studies. It was shown that rapid freeze-substitution fixation provides good preservation not only of the ultrastructure but also of the antigenicity. Both LH and FSH were clearly demonstrated in the same gonadotrophic cells, but the subcellular localization of these gonadotrophins differed: (i) LH was mainly located in small secretory granules, 250-300 nm in diameter; (ii) FSH was mainly present in large secretory granules, up to 500 nm in diameter. In the pituitary gland of the adult male rat, all gonadotrophs that react to antibodies against gonadotrophins are characterized by small and large secretory granules. Other types of cells of the anterior pituitary containing either small secretory granules or resembling corticotrophs with secretory granules assembled at cell periphery did not react to either anti-LH beta or anti-FSH beta serum. For light microscopy, the peroxidase antibody method was used. All of the gonadotrophin-positive cells contain both LH and FSH. None of the pituitary cells reacted to antibody against only one gonadotrophin. However, some cells are "LH-rich" while other cells are "FSH-rich".
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PMID:Ultrastructural immunocytochemical localization of LH and FSH in the pituitary of the untreated male rat. 642 86

Levels of testosterone, free testosterone, oestrogen, LH, FSH, prolactin were measured in 39 dialysed men. A LHRH stimulation test was performed. This study was analysed in function of the underlying renal disease, the duration of hemodialysis, and serum ferritin levels. In chronic glomerulonephritis serum gonadotrophins concentrations were significantly higher than in chronic interstitial nephritis or polycystic disease. A correlation between prolactin and ferritin was found, which may reflect the pituitary iron overload. Free testosterone levels were significantly lower in patients with gynecomastia (23-29 patients). In fact, the most direct relationship that we found with gynecomastia in dialysed men was with the free testosterone/oestrogen ratio.
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PMID:[Anomalies of human gonadal function in periodic hemodialysis: role of the etiology of kidney failure and the role of iron overload]. 687 81

To obtain further insight into gonadal function, a series of 50 prepubertal patients with beta-thalassaemia major (24 boys and 26 girls) aged from 12.6 to 18 years (mean 15 years) who had received a bone marrow transplantation (BMT) during childhood or the peripubertal period, at the age of 3.6-14.5 years (mean 10.8 years), were periodically re-evaluated at intervals of 6-12 months. The last evaluation was done 1-9 years (mean 4.2 years) after BMT. At each examination we measured height, pubertal stage, plasma gonadotrophins (LH and FSH) before and after the GnRH stimulation test (i.v.), sex steroids (total and free testosterone in males, and 17 beta-oestradiol in females), serum ferritin and bone age. Fourty percent of patients entered or passed through puberty normally despite clinical and hormonal evidence of gonadal dysfunction in most of them. A correlation was not found between the pubertal stage and age at BMT, and no statistical difference between patients who did not enter into puberty and patients with spontaneous pubertal development was found in serum ferritin levels. Our data confirm that gonads in male and female thalassaemic patients are exposed to the cytotoxic effects of the preparative transplant regime with alkylating agents. In some patients absence of pubertal development was due to gonadotrophin insufficiency, probably secondary to previous iron overload. These findings emphasize the need for a vigilant long-term follow up study of thalassaemic patients who have had BMT.
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PMID:Pubertal development in thalassaemic patients after allogenic bone marrow transplantation. 813 19

The ES 300 system, a fully automated multichannel immunoassay analyzer, was evaluated simultaneously for 9 weeks in four major centers. Precision, accuracy, carryover, comparison to in-house methods, and interferences were assessed for the following 17 tests: T4, T3, FT4, TSH, TBK, TBG, LH, FSH, prolactin, HCG, digoxin, cortisol, ferritin, IgE, insulin, AFP, and CEA. All centers reported good intra-lab and inter-lab precision. Accuracy was judged to be good based on correlation with in-house methods and recovery of target values in commercial and proficiency control materials. Linearity was evaluated for 14 analytes. Method biases were observed for T3 and insulin that were attributed to differences in standardization. No significant interferences from bilirubin, lipemia, and hemolysis were observed for all methods except insulin and AFP. Featuring random access capability, low daily maintenance, and high throughput, the ES 300 system performed well and met the stated claims of the manufacturer.
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PMID:A multicenter evaluation of the Boehringer Mannheim ES 300 immunoassay system. 844 40

This paper deals with the organization, the data processing and some of the results obtained in Italian external quality assessment (EQA) schemes for hormones, tumor markers and hepatitis B markers. The EQA for hormones and tumor markers includes up to sixteen analytes together with the participation, in 1990, of about 250 laboratories. Laboratory results were used to prepare periodic and end-of-period reports. The former includes the results (with the related statistical parameters) obtained by all participants and by laboratories using the same method, as well as the histogram of the data. The end-of-period report contains estimates of imprecision and average bias for all laboratories, for each laboratory and for the more widely employed kits. From 1980 to 1988, laboratory variability improved significantly for TSH, progesterone, estradiol, testosterone, CEA and ferritin, slightly for cortisol, FSH, prolactin and AFP, while there was no improvement for both total T3 and T4. For LH we found an unusually high variability mainly due to systematic differences between kits based on different monoclonal antibodies. About 200 laboratories participated in the EQA for hepatitis B markers (HBsAg and anti-HBs) organized in 1990. For these analytes the periodic reports show the percentage of negative and positive results and the histogram of the responses (absorbance or counts) normalized with respect to the cut off.
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PMID:Italian external quality assessment scheme in immunoassay. 854 60

The present study aimed to assess the influence of long-term therapy with recombinant human erythropoietin (rHuEPO) for 12 months on follitropin (FSH), lutropin (LH), testosterone (TE) and estradiol (E2) serum concentrations in hemodialyzed males with chronic renal failure. Two groups of hemodialyzed males with chronic renal failure were examined. The first one consisted of 20 male patients with uraemia and renal anaemia (haematocrit value < 28%). Eleven of them were treated with rHuEPO for 12 months in order to achieve and maintain a target haematocrit value (Hct) of 30-35% (EPO group). The remaining 9 male patients were only carefully monitored both clinically and biochemically (No-EPO group). Patients of both groups (EPO and No-EPO) were intensively supervised according to the same clinical and biochemical protocol. Before (0) and after 3, 6, 9 and 12 months of the study, blood samples were withdrawn for the estimation of blood haemoglobin concentration, Hct, erythrocyte count, serum ferritin concentration, transferrin saturation and serum concentrations of FSH, LH, TE and E2. In patients of the EPO group a marked increase while of the No-EPO group, a slight, but statistically significant increase of the Hct value was found after 9 and 12 months and of E2 concentration after 3, 6, 9 and 12 months of clinical monitoring. In contrast in patients of the EPO group a statistically significant decrease of serum FSH and LH concentrations (during the first 9 months of treatment) and an increase of serum TE and E2 concentrations was observed. From results obtained in this study the following conclusions may be drawn: 1. The degree of anaemia does influence significantly the hormonal profile of the pituitary-gonadal axis in haemodialyzed males with chronic renal failure. 2. rHuEPO therapy for 12 months does exert a significant, although transitory (confined to the first 6-9 months of therapy) suppressive effect on serum follitropin and lutropin levels but increases serum testosterone and estradiol levels in these patients. 3. Alterations of both haematological parameters and of hormone serum levels of the pituitary-gonadal axis observed in EPO treated patients do not seem to be due only to the administration of this hormone.
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PMID:[Influence of long-term erythropoietin (rHuEPO) therapy on the function of the pituitary-gonadal axis in hemodialyzed male patients with end stage renal failure]. 859 49

Two enriched populations of Leydig cells (hLCI and hLCII) have been characterized in human testes; it is noteworthy, that in the presence of hCG the steroid ouput is higher in hLCII when compared to hLCI; conversely, the basal production of steroids is greater in hLCI than in hLCII. The addition of increasing amounts of seminiferous tubule-conditioned medium to the purified Leydig cells leads to a dose-related enhancement of the steroid production in both Leydig cell fractions under basal and hCG-stimulated conditions. It is therefore obvious that a paracrine factor (or factors) from seminiferous tubular origin influences positively and with a high efficiency the human Leydig cell function. The human Sertoli cell synthesizes lactate, estradiol-17beta and several proteins, namely transferrin, ferritin and inhibin. In the presence of germ cells the Sertoli cell production of estradiol-17beta is decreased whereas the transferrin and inhibin outputs are enhanced. In addition the lactate dehydrogenase, gamma-glutamyl transpepetidase, alkaline phosphatase and creatine phosphokinase activities have been quantitated in various human Sertoli cell preparations. It should be kept in mind that germ cells exert an important influence on the adult Sertoli cell secretory activity through either direct contact and/or via secreted factors; moreover germ cells potentialize the stimulating effect of FSH on the Sertoli cell function and indirectly the Leydig cell output of testosterone via the Sertoli cell secretion of paracrine factor(s).
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PMID:Paracrine control of human Leydig cell and Sertoli cell functions. 896 55


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