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Biomedical subjects

G Messeri

Publications and source records attributed to G Messeri.

At least 37 records · Page 2Linked to original sources
PubMed1997

Hormonal patterns, steroid receptors and morphological pictures of endometrium in hyperstimulated IVF cycles.

OBJECTIVE: The purpose of this contribution is to investigate the pathophysiology of the abnormal endometrial development in hyperstimulated IVF cycles. STUDY DESIGN: In 12 IVF-patients who did not have embryo transfer because of failure of oocyte fertilization, serum values of 17 beta-estradiol, progesterone, FSH, LH, total and free testosterone, and androstenedione were measured on the pick-up day and were evaluated with respect to the values normally expressed in the day of ovulation; in the endometrial specimens collected 2 days later, at the time of embryo replacement, estrogen and progesterone receptors were immunohistochemically determined and dating by the Noyes method was performed. RESULTS: 17 beta-Estradiol values are constantly higher, and progesterone levels are, only in four cases, higher than expected for the day of ovulation in a natural cycle. These hormonal patterns can only partially explain the pattern of steroid receptors: progesterone receptors are expressed sparsely both in glands and stroma, while estrogen receptors are abundant in the glands and absent in the stroma. In 11 of 12 patients an abnormal endometrial development with stromal advancement was observed: this morphological picture of the endometrium could partially be explained only in the four cases presenting high progesterone levels by serum values and endometrial receptor content of estrogen and progesterone. CONCLUSIONS: The abnormal endometrial development in hyperstimulated IVF cycles could only in part be explained by estrogen and progesterone, and other factors have to be considered.

Androstenedione↗
PubMed1996

Hyperparathyroidism: is it really the major factor affecting glucose tolerance in uremia?

The effects of secondary hyperparathyroidism (sHPTH) on immunoreactive insulin (IRI) release and glucose (G) tolerance were studied in two groups of dialysis patients with normal (NPTH, n = 9) or elevated PTH levels (HPTH, n = 8), 27 +/- 24 and 660 +/- 440 pg/ml, respectively. The patients received an intravenous glucose tolerance test (IVGTT) using 0.33 g/kg of glucose solution. G, IRI and C-peptide (C-p) levels were determined calculating the G constant decay (K) and the relative incremental areas for each study. Regardless of PTH levels, all patients showed an impaired glucose tolerance (GT). IRI secretion and K values were not significantly different between the two groups. However, a significantly lower K value with a reduced (although not significant) early and late IRI secretion was found in the subgroup of patients with more severe. sHPTH (PTH: 560-1,500 pg/ml, n = 5) as compared to patients with moderate sHPTH (PTH: 87-341 pg/ml, n = 4) or normal (5-32 pg/ml, n = 8) PTH levels. No relationship was found between PTH and G, IRI or C-p levels. Our results point to a threshold limit for PTH's inhibitory effect on IRI secretion and suggest that other factors, known to affect IRI secretion and GT besides PTH levels, may modulate the role played by excess PTH levels on carbohydrate metabolism of dialysis patients.

Adult↗
PubMed1995

In-vivo studies on ovarian insulin-like growth factor I concentrations in human preovulatory follicles and human ovarian circulation.

In some recent hypotheses, the ovary has been indicated as a source of insulin-like growth factor (IGF)-I, with synthesis regulated from local steroidal and non-steroidal substances. We measured IGF-I concentrations in both serum and follicular fluid of women undergoing in-vitro fertilization (IVF) and embryo transfer, in both induced and spontaneous cycles. It was found that serum and follicular IGF-I concentrations were correlated with follicular morphology, oocyte maturity, steroid concentrations and clinical characteristics of IVF cycles. In addition, we measured IGF-I concentrations in both peripheral and ovarian circulation to gain further detailed information on the contribution of the ovary to IGF-I production. The results of our study support the hypothesis that follicular IGF-I is probably derived by diffusion from peripheral circulation and that local production appears unlikely.

Adult↗
PubMed1995

Cardiovascular function during brain natriuretic peptide infusion in man.

To investigate the cardiovascular effects of pathophysiological levels of brain natriuretic peptide (BNP), 7 healthy subjects were submitted to equilibrium radionuclide angiocardiography in baseline conditions and during BNP infusion at increasing doses (4, 8, 10 and 12 pmol/kg.min for 20 min each). BNP induced a progressive, significant reduction in left ventricular end diastolic volume, stroke volume and end systolic volume and an increase in ejection fraction and heart rate. Cardiac output, arterial pressure and peripheral vascular resistance were unchanged. Activation of the sympathetic nervous system, as indicated by the significant increase in plasma norepinephrine levels, probably played a contributory role in the maintenance of cardiovascular homeostasis. These results indicate that BNP, at pathophysiological plasma concentrations, influences cardiovascular homeostasis in man.

Adult↗
PubMed1995

Cardiovascular effects of brain natriuretic peptide in essential hypertension.

We evaluated the cardiovascular effects of pathophysiological plasma levels of brain natriuretic peptide in seven patients with mild to moderate essential hypertension by performing equilibrium radionuclide angiocardiography at baseline and during brain natriuretic peptide infusion at increasing doses (4, 8, 10, and 12 pmol/kg per minute for 20 minutes each). Brain natriuretic peptide induced a progressive reduction of left ventricular end-diastolic volume (from 107.5 +/- 10.3 to 89.0 +/- 11.0 mL at the end of all infusion periods) and end-systolic volume, whereas stroke volume did not show any significant change (from 64.9 +/- 5.9 to 62.7 +/- 7.8 mL). Cardiac output, arterial pressure, and peripheral vascular resistance did not change significantly. The lack of effects on systemic hemodynamics was probably due to compensatory activation of the sympathetic nervous system, as indicated by the significant increase in plasma norepinephrine levels (from 1.75 +/- 0.18 to 2.19 +/- 0.21 nmol/L), heart rate (from 68 +/- 6 to 81 +/- 6 beats per minute), peak ejection rate, and peak filling rate. These results indicate that brain natriuretic peptide, at the pathophysiological plasma concentrations reached in this study, influences cardiovascular homeostasis mainly by reducing cardiac preload.

Aged↗
PubMed1994

Decidual progesterone and estrogen receptors in the first trimester of pregnancy.

Receptor content of human decidua in early pregnancy (weeks 6-12) was investigated. Fifty-three tissue samples were obtained from voluntary patients undergoing abortion and whose gestational age range from 6 to 12 weeks. Blood samples were drawn at the time of operation in order to measure circulating estradiol (E) and progesterone (P) concentrations. Tissue samples underwent first histological confirmation and then were analyzed for receptor content by immunohistochemistry (IH) and by the conventional ligand binding technique (LBA). Estrogen receptors (ER) appeared to be always undetectable by IH (53 samples). LBA measured a significant amount of ER (> 10 fmol/mg) in two samples, borderline values (3-10 fmol/mg) in 6 and no binding in the other three. No relation was apparent between PR levels and either gestational age or blood P concentration. ER were possibly downregulated by the high E levels, and their synthesis inhibited by the high P levels.

Adult↗
PubMed1994

Short cycles of very low calorie diet in the therapy of obese type II diabetes mellitus.

Very Low Calorie Diet (VLCD) is known to induce not only weight loss, but also an improvement of metabolic control, in obese type II diabetics. In order to evaluate the therapeutical efficacy of cycles of VLCD shorter than those previously described, 29 obese type II diabetics and 31 obese nondiabetic subjects were entered as inpatients and prescribed a 450 kcal/day diet for 15 days. Metabolic results obtained were similar to those achieved with longer cycles of VLCD, showing that 15 days are sufficient to induce a BMI decrease in diabetic (BMI from 35.3 +/- 4.8 to 33.3 +/- 4.6 after VLCD) and nondiabetic patients (BMI from 40.5 +/- 7.4 to 38.1 +/- 7.2 after VLCD), a desired fall of blood glucose levels and the decrease of daily insulin needs in insulin-treated patients. Glucagon tests were performed before and after VLCD in order to study possible modifications of insulin secretion. Although we did not observe any significant increase of C-peptide basal or peak levels (nM/ml) either in diabetic (basal levels before VLDC: 1.2 +/- 0.4 and peak levels 2.4 +/- 0.7; basal after VLCD 1.23 +/- 0.6 and peak 2.6 +/- 0.7) and nondiabetic patients (basal levels before VLDC 1.0 +/- 0.3 and peak levels 2.5 +/- 0.4; basal after VLCD 0.9 +/- 0.3 and peak 2.4 +/- 0.6). The rise of the C-peptide/glycemia ratio is an index of an improvement of insulin biological activity, which could be partly responsible for the therapeutical effects of VLCD.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

Cardiovascular and renal effects of low dose brain natriuretic peptide infusion in man.

We evaluated the effects of pathophysiological levels of human brain natriuretic peptide (BNP), a recently identified cardiac hormone with natriuretic activity, by determining the hemodynamic and renal responses to low dose infusion (4 pmol/kg.min for 1 h, from 1500-1600 h) of human synthetic BNP in five healthy volunteers in a randomized placebo-controlled crossover study. Compared to placebo, BNP induced significant increases in effective renal plasma flow (para-aminohippurate clearance), glomerular filtration rate (creatinine clearance), urine flow rate, and sodium excretion without affecting blood pressure, heart rate, cardiac output (echocardiographic method), peripheral vascular resistance, PRA, plasma aldosterone, or plasma norepinephrine to any significant extent. Exploration of segmental sodium handling by the lithium clearance technique showed that the natriuretic effect of BNP was due to both an increase in filtered sodium load and a reduced distal sodium reabsorption. These results indicate that the high plasma BNP levels observed in disease states, such as heart failure, may contribute to the regulation of renal hemodynamics and sodium excretion.

Adult↗
PubMed1991

Comparison between single saturating dose ligand binding assay and enzyme immunoassay for low-salt extractable oestrogen and progesterone receptors in breast cancer: a multicentre study.

An excellent correlation between ligand binding assay (LBA) and enzyme immunoassay (EIA) for both oestrogen (ER) and progesterone (PR) receptors has been reported. Nevertheless, considering that the clinical value of any discrepancy between LBA and EIA probably varies with the receptor level, we undertook a collaborative study in which a single saturating dose (SSD) LBA and EIA were compared in different ER and PR dose ranges. The values of ER measured by EIA were higher in tumours with low or intermediate receptor content, causing a misclassification of ER status in 9% of cases (ER+: 77.5%, EIA, 68.8% SSD). In the case of ER, EIA values tended to be higher than SSD in all centres. For PR, EIA and SSD were generally more comparable (PR+: 66.0% EIA, 72.0% SSD, discordance rate 6%), with EIA showing, however, different trends in different centres. PR concentration was not significantly different in ER SSD-/EIA+ and in ER SSD+/EIA+ cases, suggesting that EIA detects at least in part integer ER. We conclude that although EIA may be a reliable methodological alternative to SSD, the two methods are not interchangeable until effective cut-off levels for clinical decisions are assessed for EIA.

Adult↗
PubMed1990

Alkaline phosphatases and steroid receptors in human breast cancer.

Estrogen receptors (ER), progesterone receptors (PR) and alkaline phosphatases (AP) were measured in 150 tumors from patients who underwent mastectomy for primary breast cancer. The percentage of ER positive samples was inversely related to the AP activity ranging from 88.9% in low activity samples (less than 30 U/mg prot.) down to 30.6% in the high activity ones (greater than 400 U/mg prot.). When considering only ER positive samples, the ER content was inversely related to the AP activity. This could not be demonstrated for PR. Therefore, the authors suggest the hypothesis that in human breast cancer, the AP may play a role in the dephosphorylation of the ER molecule and in the consequent modulation of its binding capability.

Alkaline Phosphatase↗
PubMed1989

Luminescent immunoassay using isoluminol derivatives.

Isoluminol derivatives (ID) were early employed in the preparation of tracers for immunoassay. Their wide use was mainly due to their high quantum efficiency, low molecular weight, well-known chemical structure, low cost and high stability. Moreover the light efficiency of some ID may be modified by specific binding to the antibody, thus allowing the development of homogenous immunoassays requiring no bound/free separation step. Some ID are commercially available under both the amino terminal and carboxyl terminal form for conjugation to respectively carboxy derivative of steroid and amino residues of protein. The linking reaction can be commonly carried on via active esters chemistry and can be easily accomplished within one day. Steroid conjugates can then be rapidly purified by silica gel thin layer chromatography, and protein conjugates by gel filtration on a short disposable column. In the field of steroid studies, isoluminol derivative conjugates were prepared for the immunoassay of almost all compounds of clinical interest. When dealing with protein, both antigens and antibody were labelled in this way, resulting in highly specific activity tracers for competitive and non-competitive immunoassays. Recently the labelling of streptavidin with amino-buty-ethyl-isoluminol allowed the development of very sensitive immunoassay methods which take advantage of the biotin-avidin system.

Avidin↗
PubMed1989

Measurement of estrone-3-glucuronide and pregnanediol-3 alpha-glucuronide in early morning urine samples to monitor ovarian function.

The determination of the concentration of estrone-3-glucuronide and pregnanediol-3 alpha-glucuronide has been performed by a chemiluminescent immunoassay in early morning urine samples of 14 normal menstruating women and 11 women affected by luteal phase defect. The early morning urine samples were daily collected for an entire menstrual cycle. We have employed a timed and measured volume collection procedure as correction factor. The integrated values of the hormonal data in definite time intervals were used to create a nomogram. By means of this method, it was possible to completely separate normal from luteal insufficiency subjects and to distinguish two different types of luteal phase defects. Moreover, the same approach was applied to the study of the role and the frequency of luteal phase defect in 15 patients affected by habitual abortion and in 17 premenopausal women who had undergone quadrantectomy for T1a No Mo breast cancer. A luteal phase defect was detected in nine of the aborting patients (60%) and in eight women affected by breast cancer (47%). Finally estrone-3-glucuronide was measured in early morning urine samples of 96 prepubertal and pubertal girls in different pubertal stages and in one patient affected by precocious puberty, before and during an agonist GnRH treatment. The urinary test of ovarian function seems to be suitable for diagnostic purposes and for clinical studies.

Abortion, Habitual↗
PubMed1989

A chemiluminescent method for the measurement of pregnanetriol-3 alpha-glucuronide in human diluted urine.

Pregnanetriol-3 alpha-glucuronide (PTG) is the majority urinary metabolite of 17-hydroxyprogesterone (17OHP) and it typically increases in the commonest form of congenital adrenal hyperplasia (CAH), due to 21 hydroxylase deficiency. We developed a simple chemiluminescent immunoassay for the direct measurement of PTG in diluted urine in order to avoid the preliminary hydrolysis and extraction steps that are usually employed in gas-liquid chromatographic methods. The immunogenic complex PTG-bovine-serum-albumin was used to induce the formation of specific antibodies in New Zealand rabbits. In addition, PTG was conjugated to aminoethylethylisoluminol and the resulting tracer was characterized by mass spectrometry and used to monitor the immunological reaction. The characteristics of the antibody were determined with regard to specificity and sensitivity. The precision of the assay method was also established. PTG excretion was studied before and after the ACTH stimulation test (1 mg synthetic ACTH i.m.) in 11 normal women and in one subject affected by CAH due to 21-hydroxylase deficiency. PTG levels well correlated with 17OHP plasma concentrations both under basal and stimulated conditions, in normal women as well as in the patient affected by CAH.

17-alpha-Hydroxyprogesterone↗
PubMed1989

Configuration and optimization of a common two-site immunoassay for human prolactin using a chemiluminescent tracer and an enzymatic tracer.

We have developed a two-site immunoassay for human prolactin using two monoclonal antibodies: one of them immobilized on the solid phase and the other labelled with biotin. The serum is incubated simultaneously with the antibody-coated bead, the biotinylated antibody and the tracer (streptavidin-isoluminol or avidin-peroxidase complex). Our experimental work has been directed towards a common set of reagents to capture the prolactin and then, with different tracers, towards obtaining on the calibration curve the same results for unknown samples. On the basis of the positive results we obtained, we have developed a kit that can be used by the customer or as an enzyme-immunoassay or as a chemiluminescent immunoassay, depending on instrumentation available, spectrophotometer or luminometer.

Antibodies, Monoclonal↗
PubMed1989

Association of estrogen receptors with parenchymal pattern at mammography.

The authors report on a consecutive series of 1,003 breast cancer cases classified on the basis of Wolfe mammographic parenchymal patterns and estrogen receptor content. The association between these two variables was investigated to assess the reliability of parenchymal patterns in predicting the estrogen receptor status. No significant association was observed after adjustment for possible confounders such as age, menopausal status, and T category. Mammographic parenchymal patterns appear to have no role in predicting estrogen receptor status.

Adult↗
PubMed1988

Prognostic significance of estrogen receptor determination in primary breast cancer.

The authors report on 767 consecutive primary Stage I-II breast cancer cases followed-up from 3 to 8 years. The estrogen receptor (ER) content was determined in all cases and did not influence the treatment choice. A correlation was attempted between ER and menstrual or pathological nodal status (N) or the 5-year disease-free survival (DFS). ER was correlated with menopausal status ER+ cases being more frequent in postmenopausal patients, whereas no correlation was observed between ER and nodal status. In absence of nodal involvement (N-) the prognosis was not influenced by the ER status. A significantly better DFS was evident for ER+ respect to ER- patients in the N+ series but such a correlation is questionable as the adjuvant treatment (hormone or chemotherapy) given to such patients may have influenced the DFS according to the ER status. According to the present study, ER determination should not be used as a discriminant in the performance of adjuvant postoperative treatment based on a prognostic judgment.

Adult↗