Biomedical subjects

A M Di Blasio

Publications and source records attributed to A M Di Blasio.

At least 19 recordsLinked to original sources

PubMed2006

Predictors of postabsorptive ghrelin secretion after intake of different macronutrients.

CONTEXT: Release of ghrelin, a gastrointestinal hormone regulating feeding and energy balance, is blunted in obesity, a condition associated with insulin resistance. OBJECTIVE: The objective was to identify anthropometric and metabolic predictors of postabsorptive ghrelin secretion. DESIGN: We evaluated ghrelin, insulin, glucose, and leptin secretion overnight and after intake of different macronutrients. SUBJECTS: Ten obese subjects (age, 31.8 +/- 2.5 yr; body mass index, 43.4 +/- 0.8 kg/m(2)) and six lean subjects (age, 33.5 +/- 2.4 yr; body mass index, 21.8 +/- 1.4 kg/m(2)) participated in the study. MAIN OUTCOME MEASURES: The main outcome measures were resting energy expenditure (REE); fat mass; nighttime approximate entropy (ApEn) and synchronicity (cross-ApEn) of ghrelin, insulin, and leptin; insulin sensitivity by homeostatic model approach insulin-sensitivity (HOMA-S%); postabsorptive area under the curve (AUC); and Delta of ghrelin, insulin, glucose, and leptin after carbohydrate-, lipid-, and protein-rich test meals. RESULTS: Nighttime ApEn scores were higher in obese than lean subjects (P < 0.01). Cross-ApEn revealed a synchronicity between ghrelin-insulin, ghrelin-leptin, and insulin-leptin in both groups. Compared with baseline, ghrelin decreased significantly (P < 0.01) in lean and obese subjects after carbohydrates (42.2 vs. 28.5%; P < 0.05), lipids (40.2 vs. 26.2%; P < 0.01), and proteins (42.2 vs. 26.3%; P < 0.01) devoid of between-meal ghrelin differences. Significant associations occurred between nocturnal ghrelin ApEn and insulin (r = 0.53; P < 0.05), postmeal ghrelin AUCs and REE (r = -0.57; P < 0.05), and HOMA-S% (r = 0.52; P < 0.05), postmeal ghrelin Delta and HOMA-S% (r = 0.60; P < 0.05). REE (beta = -0.57; P = 0.02) and ghrelin ApEn (beta = -0.62; P = 0.01) were predictors of postmeal ghrelin AUC and Delta, respectively. CONCLUSIONS: Obesity determined a decreased orderliness of ghrelin secretion and a relative loss of ghrelin-insulin synchrony. Postabsorptive ghrelin secretion decreased significantly both in obese and lean subjects, was related to insulin sensitivity, and was predicted by energy expenditure and hormone pulsatility.

Adult↗

PubMed2006

Lack of association between the tetranucleotide repeat polymorphism in the 3'-flanking region of the leptin gene and hypertension in severely obese patients.

Conflicting data suggest an association between leptin gene polymorphisms and essential hypertension independently of obesity. The aim of this study was to evaluate, in severely obese subjects, the role of one of these polymorphic markers in relation to the development of hypertension. The study included 325 obese patients with mean body mass index (BMI) of 46+/-6.94 kg/m2. One hundred sixty-six were hypertensive and 159 normotensive. In both groups, the presence of a tetranucleotide repeat in the 3' flanking region of the Ob gene was investigated using polymerase chain reaction (PCR). Due to the genetic variant, in the region studied it is possible to distinguish two alleles with different size distribution: Class I (shorter one) and Class II (longer one). Class I and Class II allele frequencies were not significantly different in obese patients when analyzed according to the presence or absence of hypertension. The results presented herein do not support a significant association of this Ob gene polymorphism with hypertension. These findings are in contrast with that reported in other populations. However, we cannot rule out that different ethnicity and/or phenotypic variability might mask small effects.

3' Flanking Region↗

PubMed2006

Human decidual natural killer cells as a source and target of macrophage migration inhibitory factor.

The human uterine mucosa of early pregnancy is largely populated by CD56(bright) natural killer (NK) cells (uterine (u) NK cells). The specific functions of these cells are still unknown, but their interaction and response to foetal trophoblasts are thought to be important for the establishment of a successful pregnancy. The study reported herein shows that uNK cells respond to, and produce, macrophage migration inhibitory factor (MIF), a cytokine highly expressed in the human placenta and in the cyclic and pregnant endometrium. Recombinant human MIF reduced in a dose-dependent manner the cytolytic activity of purified uNK cells against K562 cells. RT-PCR, Western blot analysis and ELISA demonstrated the synthesis and secretion of the cytokine by uNK cells. Double immunofluorescence staining showed the presence of MIF in uterine CD56 + cells. Finally, neutralization of the endogenous cytokine by a polyclonal antibody resulted in a sharp increase in the cytolytic activity of uNK cells. These findings indicate the existence of a previously unrevealed paracrine and autocrine action of MIF on uNK cells and support its contribution to the immune privilege at the maternal-foetal interface.

Antibodies, Monoclonal↗

PubMed2006

Cycling and early pregnant endometrium as a site of regulated expression of the vitamin D system.

In addition to its calciotropic function, the secosteroid 1,25-dihydroxyvitamin D(3) (1,25(OH)(2)D(3)), has potent anti-proliferative/immunomodulatory effects on various tissues. Consistently, the enzyme that catalyzes the synthesis of 1,25(OH)(2)D(3), 1alpha-hydroxylase (1alpha-OHase) and the vitamin D receptor have a widespread tissue distribution. Among site-specific functions, the hormone has been suggested to be involved in uterine physiology. However, molecular analysis of the vitamin D system in normal endometrium throughout the menstrual cycle as well as its regulation in the context of endometrial physiological and pathological events have received very limited attention. Thus, we have studied expression, localization and regulation of 1alpha-OHase in human cycling and early pregnant endometrium. The capacity for 1alpha-hydroxylation and the presence of vitamin D receptor in endometrial cells have also been evaluated. The functional significance of these findings has been tested by evaluating gene expression of the catabolic enzyme, vitamin D 24-hydroxylase, and of the adhesion protein, osteopontin. Finally, to verify any potential dysfunction of the vitamin D system in endometriosis, a reproductive disease characterized by immune-mediated anomalies, we have analyzed expression of 1alpha-OHase in both eutopic and ectopic endometrium of affected patients. Results obtained showed that the active form of the 1alpha-OHase gene was expressed in human endometrial stromal cells independent of the cycle phase but with a significant increase in early pregnant decidua. A similar profile was observed for the protein, which was abundantly expressed in the cytoplasm of both endometrial stroma and epithelial glands. Both cycling and early pregnant endometrial cells also expressed the vitamin D receptor. In the same cells, 1alpha-OHase mRNA levels were significantly stimulated by the pro-inflammatory cytokine interleukin (IL)-1beta (50 and 500 pg/ml) while addition of the active form of the hormone could modulate both CYP24 and osteopontin gene expression. The 1alpha-OHase gene was also expressed in ectopic endometrium and its levels were increased in proliferative phase cultures derived from patients with endometriosis. Human cycling endometrium may be included among the extrarenal sites able to synthesize vitamin D. The IL-1beta-mediated induction of 1alpha-OHase gene and the hormonal modulation of osteopontin support a role for the hormone in the immunological mechanisms underlying uterine function. Abnormalities of this system are present in endometriosis.

25-Hydroxyvitamin D3 1-alpha-Hydroxylase↗

PubMed2005

Genetics of endometriosis.

UNLABELLED: Endometriosis is a multifactorial disease that can affect up to 10-15% of women in their reproductive age. Epidemiological studies indicate that it is a polygenic disorder with recurrence risks in first-degree relatives of about 5-7%. Thus, the present aim of different research groups is to identify genetic variations in obvious candidate gene that could be associated with an increased susceptibility to endometriosis. The great advancement in molecular biology techniques make this task certainly possible, although particular attention needs to be paid to the study design in order to achieve reliable RESULTS: The data obtained by such studies will allow to expand our knowledge on the pathogenesis of the disease and, more importantly, to develop individualized therapies and prevention strategies to apply at high-risk populations.

Alleles↗

PubMed2004

Analysis of the codon 72 polymorphism of the TP53 gene in patients with endometriosis.

Endometriosis is a benign gynaecologic disease that is associated with a certain risk for malignant degeneration. The disease has a genetic background, but the locations of possible genomic aberrations are still poorly clarified. In this context, the proline form of TP53 codon 72 polymorphism has been recently associated with the risk of developing endometriosis. In this case-control study, we aimed to investigate further the potential association between endometriosis and this polymorphism in order to evaluate whether this genetic variant may influence the susceptibility to the disease. Genomic DNA was obtained from a consecutive series of 303 Italian Caucasian women of reproductive age who underwent laparoscopy for benign gynaecological pathologies. Endometriosis was defined according to the criteria of Holt and Weiss [Holt V and Weiss NS (2000) Recommendations for the design of epidemiologic studies of endometriosis. Epidemiol 11,654-659] for the definite disease. Subjects of similar age without laparoscopic evidence of the disease served as control group. Molecular analysis of TP53 codon 72 polymorphism was performed by PCR amplification. Endometriosis was documented in 151 women. We found no statistically significant difference in the distribution of TP53 codon 72 polymorphism genotypes between patients with and without endometriosis. The respective proportions of arginine homozygotes, heterozygotes and proline homozygotes were 55.6, 39.7 and 4.6% in the group with endometriosis and 59.9, 30.9 and 9.2% in the control group. Moreover, no statistically significant association was demonstrated between TP53 codon 72 polymorphism and the various clinical manifestations of the disease, although a non-significant tendency towards an increased frequency of the proline allele was observed in association with specific manifestations of the disease reflecting a more severe form. Our results suggest that the TP53 codon 72 polymorphism does not confer genetic susceptibility to endometriosis in the Italian population. However, a possible susceptibility role of this polymorphism in endometriosis development towards very severe forms cannot be ruled out.

Adult↗

PubMed2004

Use of the concomitant serum dosage of CA 125, CA 19-9 and interleukin-6 to detect the presence of endometriosis. Results from a series of reproductive age women undergoing laparoscopic surgery for benign gynaecological conditions.

BACKGROUND: Recent studies have proposed the measurement of CA 19-9 and IL-6 as an alternative to CA 125 as markers for endometriosis. This study was performed in order to verify the clinical value of serum CA 125, CA 19-9 and IL-6 levels, either by themselves or combined, in the detection of the disease. METHODS: In a prospective cohort study, serum concentrations of CA 125, CA 19-9 and IL-6 were measured in a consecutive series of 80 women of reproductive age who underwent laparoscopy for benign gynaecological pathologies. RESULTS: Endometriosis was documented in 45 women (stage I-II in 14 cases and stage III-IV in 31 cases). Patients with endometriosis had significantly higher levels of CA 125 than controls [23.4 IU/ml (13.3-37.6) versus 11.4 IU/ml (9.1-18.5), P < 0.001)]. Conversely, women with and without the disease were shown to have similar levels of both IL-6 pg/ml [0.6 (undetectable-1.4) versus 1.0 pg/ml (0.4-1.9), P = 0.09] and CA 19-9 [9.8 IU/ml (4.5-20.8) versus 7.4 IU/ml (2.8-11.5), P = 0.11]. The area under the receiver operating characteristics curve resulted in a statistically significant difference from the null hypothesis only for CA 125 (P < 0.001). Sensitivity and specificity of CA 125 were 27 and 97% respectively and were higher than those related to CA 19-9 and IL-6. Concomitant use of the three dosages led to a sensitivity and a specificity of 42 and 71% respectively. CONCLUSIONS: The concomitant dosage of CA 125, CA 19-9 and IL-6 does not add significant information in respect to the CA 125 test alone in diagnosing either early or advanced stages of endometriosis.

Adult↗

PubMed2003

Lack of association between UCP2 gene polymorphisms and obesity phenotype in Italian Caucasians.

The importance of the genetic component on adipose tissue accumulation has been clearly demonstrated. Among the candidate genes investigated, there are those that regulate thermogenesis and, thus, can affect energy expenditure. The uncoupling proteins (UCPs) are a family of proteins that uncouple respiration leading to generation of heat and increased energy expenditure. Contradictory data indicate that allelic variants in their coding genes might be associated with obesity. In this study we evaluated the role of two allelic variants of the UCP2 gene in obesity and the association with its sub-phenotypic characteristics. To this aim, 360 morbidly obese patients [age: 45 +/- 15 yr, body mass index (BMI): 46 +/- 7 kg/m2] and 103 normal weight subjects (BMI < 24 kg/m2) were genotyped for the 45 bais-pair (bp) insertion/deletion (I/D) in the 3'-untraslated region of exon 8 of the UCP2 gene while the presence of an Ala/Val substitution at codon 55 (Ala55Val) of the same gene was studied in 104 obese and 50 lean subjects. Patients also underwent a study protocol including measurements of BMI, waist-to-hip ratio (WHR), resting energy expenditure (REE), energy intake, fat mass (FM) and free fat mass (FFM), total cholesterol (TCH), high density lipoprotein (HDL) cholesterol, triacylglyceroles (TG), leptin levels, basal glucose, immunoreactive insulin (IRI), glycated haemoglobin (HbA1c), insulin sensitivity and thyroid hormones. No significant association between the two polymorphisms studied and the clinical, metabolic and anthropometric parameters characteristic of the obese phenotype was found. These results, in accordance with similar findings previously obtained in other ethnic groups, suggest that these two UCP2 allelic variants may not have a direct role in the pathogenesis and development of obesity.

Adult↗

PubMed2003

Different basic fibroblast growth factor and fibroblast growth factor-antisense expression in eutopic endometrial stromal cells derived from women with and without endometriosis.

In all species studied, the basic fibroblast growth factor (bFGF) gene is transcribed into multiple mRNAs, one of which is an antisense RNA (1B FGF-AS) probably involved in regulating the stability of the sense transcript. In this study we investigated whether the regulatory mechanisms of bFGF expression might be altered in endometrial stromal cells derived from women with endometriosis. bFGF and 1B FGF-AS mRNA levels were quantified in primary cultures of eutopic endometrial stromal cells derived from 29 women without endometriosis and 24 patients affected by the disease. When the data were analyzed according to the phase of the menstrual cycle, endometrial stromal cells derived from patients in the late proliferative phase showed significantly higher bFGF mRNA values and significantly lower 1B FGF-AS mRNA levels compared with control samples. Furthermore, the mean bFGF/1B FGF-AS mRNA ratio was significantly higher in endometrial stromal cells derived from patients compared with that in controls (mean +/- SEM, 2.31 +/- 0,55 and 0.77 +/- 0.14, respectively; P = 0.009). Moreover, for bFGF expression the differences existing at the mRNA level were maintained at the protein level. These findings support the hypothesis that 1B FGF-AS mRNA could regulate the expression of the sense transcript and suggest that in endometrial cells derived from patients, the presence of higher bFGF levels could improve their ability to proliferate at the ectopic site.

Base Sequence↗

PubMed2002

Identification of urocortin mRNA and peptide in the human endometrium.

Urocortin is a 40-amino acid peptide belonging to the corticotropin-releasing factor (CRF) family. In human reproductive tissues, urocortin expression has been previously demonstrated in the ovary, in the placenta and fetal membranes and in pregnant uterine tissues, while no data are available on the expression of the peptide in the nonpregnant uterus. In this study, urocortin expression was evaluated by both immunohistochemistry and reverse transcription-polymerase chain reaction, in human uterine tissues and cells at different phases of the menstrual cycle. Urocortin was immunolocalized in endometrial epithelial and stromal cells, as well as in the myometrium, and in vascular smooth muscle cells. No differences between proliferative and secretory phase were observed. These results were confirmed by reverse transcription-polymerase chain reaction analysis of isolated endometrial epithelial and stromal cells, and myometrial specimens. These findings open new questions on the roles played by urocortin in the human uterus.

Corticotropin-Releasing Hormone↗

PubMed2001

Evidence for local production of inhibin A and activin A in patients with ovarian endometriosis.

OBJECTIVE: To evaluate the expression of inhibin A and activin A in ovarian endometriosis. DESIGN: Uncontrolled cross-sectional study and controlled prospective in vitro study. SETTING: Academic health centers in Siena, Udine, Sassari, and Milan, Italy. PATIENT(S): A group of women (n = 19) who underwent laparoscopic excision of ovarian endometriotic cysts. INTERVENTION(S): Specimens of serum, peritoneal fluid, and cystic fluid, ovarian tissue for immunohistochemistry, and endometriotic cells for primary culture were collected. Cell cultures were also prepared from proliferative endometrium of women without endometriosis. MAIN OUTCOME MEASURES: Dimeric inhibin A and activin A concentrations in biological fluids; immunostaining of alpha and betaA subunits in ovarian endometrioma; alpha and betaA gene expression in cultured endometriotic cells compared with normal endometrium. RESULT(S): Inhibin A and activin A concentrations in the cystic fluid were slightly higher than in peritoneal fluid and significantly higher than in serum (P<.05). Immunoreactive alpha and betaA subunits were strongly expressed both in the epithelial and stromal components of ovarian endometrioma. The relative abundance of betaA mRNA was significantly decreased in endometriotic cells compared with eutopic stromal cells. CONCLUSION(S): The results of the present study provide evidence for a local production and secretion of inhibin A and activin A in ovarian endometriotic cysts.

Activins↗

PubMed2001

Suppression of natural killer cell function and production of soluble ICAM-1: endometrial stroma versus melanoma.

PROBLEM: It has been suggested that specific mechanisms commonly used by different cellular systems to evade immunologic recognition are involved in the development of endometriosis. To gain insight into this aspect, we looked at the relationship between two of these mechanisms in endometrial stroma and the melanoma system for which the ability to create an environment of immune privilege has been well established. METHOD OF STUDY: Media conditioned by endometrial stromal cultures and malignant melanoma A375 were examined to test their effects on peripheral blood mononuclear cell-mediated cytotoxicity directed against K562 target. Moreover, these media were tested for the concentration of the soluble form of intercellular adhesion molecule-1 (sICAM-1), which has been suggested as a marker for spreading potential. RESULTS: Media conditioned by endometrial stromal cultures exerted a significant suppressive effect on cell cytotoxicity when compared with those derived from malignant melanoma Moreover, the constitutive release of sICAM-1 was significantly higher in supernatants from endometrial stromal than in melanoma cells. CONCLUSIONS: These results indicate that two specific properties suggested to be involved in the ability of tumor cells to evade the immune system are more pronounced in the endometrium than in a malignant melanoma. Since the properties evaluated have been previously demonstrated to be even more notable in endometrial samples derived from endometriosis patients, a role of these mechanisms in the development of the disease may be hypothesized.

Cytotoxicity, Immunologic↗

PubMed2001

Somatostatin receptor subtype 2 and 5 in human GH-secreting pituitary adenomas: analysis of gene sequence and mRNA expression.

The role of somatostatin receptor subtypes 2 and 5 (SSTR2 and SSTR5) in determining the secretory and proliferative phenotype as well as the sensitivity to somatostatin analogue treatment is not clearly established. We quantified the expression of SSTR2 and SSTR5 mRNA using a semiquantitative reverse transcription-polymerase chain reaction (RT-PCR) in 19 human growth hormone (GH) -secreting adenomas. Tumour characteristics and in vivo sensitivity to somatostatin analogues were assessed; tumours were screened for Gsalpha gene mutations. PCR products of SSTR2 and SSTR5 DNA from tumours resistant to somatostatin analogues were directly sequenced. All tumours expressed both SSTR2 and SSTR5 mRNA at variable levels. No significant correlation between SSTR2 and SSTR5 expression and the presence of Gsalpha mutation, GH levels, or tumour size and invasiveness was observed. A negative correlation between SSTR2 and SSTR5 mRNA levels was observed (r = 0.5; P < 0.05). No significant correlation between the levels of SSTR2 and SSTR5 expression and the in vivo responsiveness to somatostatin analogues was observed, although a tendency to a low SSTR2 expression in resistant tumours was found. No mutations in the coding or bordering regions of either SSTR2 or SSTR5 adenomatous DNA from patients totally or partially resistant to somatostatin analogues were found. The study shows that the different expression of SSTR2 and SSTR5 in GH-secreting adenomas is not significantly correlated with the secretory and proliferative phenotype, although the large, hypersecretory tumours and those with a poor sensitivity to somatostatin analogues seem to express low levels of SSTR2 mRNA. Moreover, both SSTR2 and SSTR5 DNA from tumours resistant to somatostatin analogues were found to possess intact coding sequences.

Adenoma↗

PubMed2001

Interleukin-10 is produced by human uterine natural killer cells but does not affect their production of interferon-gamma.

A predominance of T helper (Th)2-type cytokines and a weakening of Th1 responses seem to be critical for the maintenance of a successful gestation. Among Th2-type cytokines, interleukin (IL)-10 is produced by human cytotrophoblasts and defects in this production result in specific pathological conditions of pregnancy. The current opinion is that IL-10 serves to protect the fetus from a harmful maternal immune response. However, production of the cytokine and its direct effect on uterine natural killer (uNK) cells, which represent the predominant lymphocyte population infiltrating the pregnant endometrium, are largely unknown. Thus, to shed light on the cytokine network at the maternal-fetal barrier during early pregnancy, we investigated the IL-10 system in uNK cells. We showed that uNK cells express the mRNA transcripts for IL-10 and IL-10 receptor. Production of IL-10 by the uNK cells was enhanced by both IL-2 and IL-12. Treatment with IL-10 alone enhanced uNK cell cytotoxic activity. In contrast, the cytokine did not modify the basal or stimulated production of interferon (IFN)-gamma by uNK. Thus, IL-10 does not act as a direct antagonist of uNK cell function and activation. However, IL-10 produced by uNK cells in response to IL-12 and IL-2 may still have a feedback inhibitory effect on the production of deleterious cytokines within the uterine microenvironment.

Cells, Cultured↗

PubMed2000

Expression of GnRH receptor gene in human ectopic endometrial cells and inhibition of their proliferation by leuprolide acetate.

The present study was conducted to investigate whether GnRH-receptor (GnRH-R) gene is expressed in endometriosis ovarian implants and whether a GnRH-analogue (GnRH-a) may exert an effect on endometriosis cell proliferation in vitro. The presence of GnRH-R transcripts in ovarian endometriosis cells was assessed by reverse transcription-polymerase chain reaction (RT-PCR) and further confirmed by Southern blot analysis. GnRH-R mRNA was detected in all the 13 samples examined. In contrast, GnRH-R transcripts were not detectable in endometriosis-free peritoneal tissue. In the second part of the study, endometriosis cells were cultured for 9 days with different doses of leuprolide acetate (ranging from 0 to 10(-5) M). In 4 out of 13 cases, a significant anti-proliferative effect was observed at doses of leuprolide acetate ranging from 10(-9) to 10(-5) M. In one case, a significant inhibition of cell proliferation was observed only at 10(-5) M leuprolide acetate concentration. In contrast, the GnRH-a did not affect cell growth, regardless of the expression of GnRH-R transcripts and the given doses, in the remaining 8 experiments. To date, this is the first evidence indicating that GnRH-R mRNA is expressed in human ovarian endometriomas. Moreover, the inhibition of endometriosis cell proliferation induced by the GnRH-a in vitro suggests that, at least in some cases, this compound might exert a direct effect on endometriosis lesions.

Adult↗

PubMed2000

Calcium-sensing receptor expression and signalling in human parathyroid adenomas and primary hyperplasia.

OBJECTIVE: Both in vivo and in vitro evidence indicates that primary hyperparathyroidism is characterized by a reduced sensitivity to extracellular calcium ([Ca2+]o). The existence of alterations in the expression and signalling of calcium sensing receptor (CaSR) in parathyroid neoplasia is still uncertain. In order to clarify the role of CaSR in the reduced [Ca2+]o sensing of parathyroid neoplasia we investigated PTH secretion and intracellular effectors triggered by CaSR activation as well as the levels of expression of CaSR and CaSR coupled G proteins (Gq/G11) in parathyroid adenomas and primary hyperplasia. MATERIALS AND METHODS: The study included 27 parathyroid adenomas, 4 cases of primary hyperplasia and pools of normal parathyroid biopsies. Tissues were either snap frozen in liquid nitrogen or placed in sterile medium for cell dispersion. The effects of increasing [Ca2+]o on in vitro PTH release, intracellular cAMP levels and intracellular calcium ([Ca2+]i) in cells loaded with the Ca2 + indicator fura-2 were evaluated. CaSR mRNA levels were assessed by semiquantitative RT-PCR analysis, using GAPDH as internal standard, while CaSR protein was detected by western blot analysis using a specific polyclonal antibody. Purified antisera selective for G11alpha and Gqalpha were used to detect this class of proteins. RESULTS: In basal conditions (at 0.5 mM [Ca2+]o) in vitro PTH released ranged from 29.4 to 1186 pg/well/60 minutes. Increasing [Ca2+]o from 0.5 to 1, 2.5 and 5 mM caused a variable effect. One group (n = 7) showed a significant but partial reduction of PTH release (of 17 to 60% of basal levels) that occurred at physiological [Ca2+]o concentrations (1 mM) while the remainder showed either inhibition detectable only at 2.5 mM (n = 15) or total (n = 9) resistance to [Ca2+]o. In the responsive cells, [Ca2+]o (1-5 mM) caused a pertussis toxin-insensitive [Ca2+]i rise (ranging from 10% to 260%), due to Ca2+ release from intracellular stores, and an inhibition of forskolin-stimulated cAMP levels. By RT-PCR almost all tumours tested showed a substantial reduction in CaSR mRNA levels when compared to the normal tissue (CaSR/GAPDH ratio: 3.1 +/- 0.5 vs. 15.5 +/- 3.1; P < 0.001), which was confirmed by immunoblotting analysis demonstrating low levels of CaSR protein in tumour tissues. Moreover, low amounts of G11alpha and Gqalpha, the G proteins involved in CaSR coupling, were observed in the majority of pathological tissues. CONCLUSIONS: The study shows that the activation of the calcium sensing receptors expressed in adenomatous parathyroid glands modulates intracellular effectors in a similar way to those operating in the normal parathyroid. Although a reduction of calcium sensing receptor expression is probably involved in the poor inhibition of PTH release induced by [Ca2+]o, this is not the only factor altering [Ca2+]o sensing in parathyroid adenomas, since tumours characterized by different in vitro sensitivity to [Ca2+]o showed similar CaSR levels. The low content of G proteins of the Gq subfamily might represent an additional alteration leading to a defective [Ca2+]o sensing.

Adenoma↗

PubMed2000

The A19G polymorphism in the 5' untranslated region of the human obese gene does not affect leptin levels in severely obese patients.

Recently, the presence of different polymorphisms in the regulatory region of the ob gene has been associated with variations in leptin levels. However, the results of these studies are still contradictory. The aim of the present investigation was to evaluate the presence of the A19G polymorphism in an Italian population of obese patients and to verify its association with leptin levels and anthropometric, metabolic, and clinical parameters. Two hundred five obese patients [body mass index (BMI) > 36 kg/m2; 135 women and 70 men; mean age, 46.9+/-14.23 yr] were screened for presence of the polymorphism; 61 normal-weight controls (mean BMI, 21.05 kg/m2; 53 women, 8 men) were also screened to compare polymorphism frequency. For obese patients, BMI, waist-to-hip ratio, resting energy expenditure, body composition, fasting leptin, total cholesterol, high-density lipoproteins, triglycerides, and caloric intake were determined. Genotype frequencies in obese and control subjects were compared using the contingency table chi-square test; in obese subjects an ANOVA was performed to evaluate association between the polymorphism and several clinical parameters. No significant differences in genotype distribution between control and obese subjects were found. No significant correlations were found between this polymorphism and serum leptin levels and the other parameters considered. These findings confirm the results obtained in both a Finnish and a French population; taken together, these observations might rule out a significant role for the A19->G polymorphism in the regulation of leptin levels and other clinical, anthropometric, and metabolic parameters.

5' Untranslated Regions↗

PubMed2000

Unexplained habitual abortion is associated with a reduced endometrial release of soluble intercellular adhesion molecule-1 in the luteal phase of the cycle.

Although the mechanisms causing recurrent spontaneous abortion (RSA) remain frequently speculative, recent evidence indicates that a specific uterine immune-endocrine network plays a pivotal role in the continuation of pregnancy. We have recently demonstrated that an adhesion molecule of the immune system, named intercellular adhesion molecule (ICAM)-1, is markedly expressed at both protein and mRNA levels in endometrial stromal cells and is able to mediate their interaction with lymphoid cells. Moreover, we have shown that the soluble form of ICAM-1 (sICAM-1) can be released by the endometrium in a hormone-dependent manner. The present study was designed to determine whether surface and/or sICAM-1 expression by cultured endometrial stromal cells could be related to early pregnancy loss in patients with a history of unexplained RSA. Luteal-phase endometrial biopsies were obtained from eight patients who had experienced three or more consecutive unexplained RSAs in the first trimester and 12 control fertile women. Surface ICAM-1 was similarly expressed on luteal-phase endometrial cells obtained from women with and without a history of unexplained RSA. In contrast, the endometrial release of sICAM-1 was significantly lower in abortion-prone patients than in control women. sICAM-1 is a cytokine-inducible molecule able to interfere with several immunological responses and the reduced levels of the protein shed by the endometrium in patients who have suffered from unexplained RSAs may reflect the presence of an altered immunological environment during the early phases of pregnancy.

Abortion, Habitual↗