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G Bernini

Publications and source records attributed to G Bernini.

At least 19 recordsLinked to original sources
PubMed2002

Adrenal surgery before and after the introduction of laparoscopic adrenalectomy.

BACKGROUND: The widespread introduction of laparoscopic adrenalectomy (LA) may have broadened the indications for a surgical approach to adrenal lesions. The aim of this study was to evaluate how the introduction of the laparoscopic technique changed the profile of patients referred for adrenal surgery. METHODS: Some 243 patients, who underwent adrenal surgery between November 1986 and December 1999, were divided in two groups: patients in group 1 underwent surgery before the introduction of LA (November 1986 to May 1993) and those in group 2 were operated on after the introduction of LA (June 1993 to December 1999). The groups were compared with respect to gender, age, preoperative diagnosis and lesion size. RESULTS: There were 88 patients in group 1 and 155 in group 2. The mean number of adrenal operations per month was 1.1 during the first period and 2.0 during the second. No differences were found in gender and lesion size. The statistical analysis showed a significant difference in indications for surgery (P = 0.005). The patients in group 2 were older but, after excluding those with metastases, the difference between the two groups was not significant. CONCLUSION: The introduction of LA resulted in an increase in the number of patients referred. The criteria for patient selection did not change, but more patients with adrenal metastases and incidentaloma were operated on laparoscopically.

Adolescent↗
PubMed2001

Somatostatin receptor type 2 gene expression in neuroblastoma, measured by competitive RT-PCR, is related to patient survival and to somatostatin receptor imaging by indium -111-pentetreotide.

BACKGROUND: We previously reported that human neuroblastoma cell lines and primary neuroblastoma tumors expressed a variable amount of mRNA for type 2 somatostatin (sst2) receptor gene. We also found that high level of sst2 expression were positively related to patient survival. PROCEDURE: We studied retrospectively 49 primary neuroblastomas. To detect and measure sst2 mRNA expression we developed a quantitative RT-PCR based on competitive PCR. When possible the number of MYCN copies was also measured with competitive PCR. RESULTS;. We found that the lowest level of sst2 mRNA was detected in advanced stages of neuroblastomas (stage IV) when compared with the other stages (P< 0.005). Patients with high levels of sst2 expression (>7 x 10(7) molecules/microg RNA) had a cumulative survival better than those with low sst2 expression (P < 0.0005). This predictive independent value of sst2 (P= 0.005) is retained after stratification for N-myc amplification. Finally we verified that the ex vivo sst2 gene expression in tumor samples was positively related (P < 0.01) to the in vivo semiquantitative determination of sst2 protein, assessed by 111In-pentetreotide imaging. CONCLUSIONS: Our data indicate that the measurement of sst2 mRNA measurement could represent a relevant tool in the prediction of neuroblastoma outcome, independently from MYCN amplification.

Biomarkers, Tumor↗
PubMed2001

Mechanisms responsible for endothelial dysfunction induced by fasting hyperhomocystinemia in normotensive subjects and patients with essential hypertension.

OBJECTIVES: We sought to evaluate whether fasting hyperhomocystinemia reduces endothelial function by oxidative stress in normotensive subjects and hypertensive patients. BACKGROUND: Subjects with hyperhomocystinemia have endothelial dysfunction. METHODS: In 23 normotensive subjects and 28 hypertensive patients, classified into normohomocystinemic and hyperhomocystinemic groups according to homocysteine plasma levels (< 8.7 and >14.6 micromol/l, respectively), we studied forearm blood flow changes (strain-gauge plethysmography) induced by intrabrachial administration of acetylcholine (0.15 to 15 microg/100 ml tissue per min) or sodium nitroprusside (1 to 4 microg/100 ml per min), an endothelium-dependent and -independent vasodilator, respectively. Acetylcholine was repeated with N(G)-monomethyl-L-arginine (L-NMMA; 100 microg/100 ml per min), vitamin C (8 mg/100 ml per min) and L-NMMA plus vitamin C. RESULTS: Normotensive hyperhomocystinemic patients showed a blunted response to acetylcholine and a lower inhibiting effect of L-NMMA on acetylcholine, as compared with normohomocystinemic patients. Although vitamin C was ineffective in normohomocystinemic subjects, it increased the response to acetylcholine and restored the inhibiting effect of L-NMMA on acetylcholine in hyperhomocystinemic patients. Hypertensive hyperhomocystinemic patients showed a reduced response to acetylcholine, as compared with normohomocystinemic subjects. In both subgroups, L-NMMA failed to blunt the response to acetylcholine. The potentiating effect of vitamin C on acetylcholine was greater in hyperhomocystinemic patients than in normohomocystinemic subjects, although it restored the inhibitory effect of L-NMMA on acetylcholine-induced vasodilation to the same extent in both groups. Hyperhomocystinemia did not change the response to sodium nitroprusside. CONCLUSIONS: In normotensive subjects and hypertensive patients, hyperhomocystinemia impairs endothelium-dependent vasodilation. It could be related to oxidant activity.

Acetylcholine↗
PubMed2001

Age-related reduction of NO availability and oxidative stress in humans.

Age-related endothelial dysfunction could be caused by an alteration in the L-arginine-NO system and the production of oxidative stress in both normotensive and hypertensive individuals. In 47 normotensive subjects and 49 patients with essential hypertension, we evaluated forearm blood flow (by strain-gauge plethysmography) modifications induced by intrabrachial sodium nitroprusside (1, 2, and 4 microg/100 mL per minute) and acetylcholine (0.15, 0.45, 1.5, 4.5, and 15 microg/100 mL per minute), an endothelium-independent vasodilator and an endothelium-dependent vasodilator, respectively. Acetylcholine was repeated in the presence of the NO synthase inhibitor N(G)-monomethyl-L-arginine (L-NMMA, 100 microg/100 mL per minute), the antioxidant vitamin C (8 mg/100 mL per minute), or both. Vasodilation to acetylcholine, but not to sodium nitroprusside, was lower (P<0.01) in hypertensive patients compared with control subjects. Moreover, in both groups, endothelium-dependent vasodilation declined with aging. In normotensive subjects, the inhibiting effect of L-NMMA on response to acetylcholine decreased in parallel with advancing age, whereas vitamin C increased vasodilation to acetylcholine in only the oldest group (age >60 years). In young hypertensive patients (age <30 years), vasodilation to acetylcholine was sensitive to L-NMMA, whereas in hypertensive patients age >30 years, vitamin C enhanced endothelium-dependent vasodilation and restored the inhibiting effect of L-NMMA on response to acetylcholine. In normotensive individuals, an earlier primary dysfunction of the NO system and a later production of oxidative stress cause age-related reduction in endothelium-dependent vasodilation. These alterations are similar but anticipated in hypertensive patients compared with normotensive subjects.

Acetylcholine↗
PubMed2001

Neoadjuvant chemotherapy for patients with synchronous multifocal osteosarcoma: results in eleven cases.

Between January 1995 and December 1999, 11 patients with synchronous multifocal osteosarcoma (SMO) received neoadjuvant treatment with high-dose methotrexate, cisplatinum, Adriamycin, and ifosfamide. After primary chemotherapy in 4 patients who had only two bone localizations, it was possible to treat all tumor foci locally. The remaining patients, with more than three bones involved, were treated surgically only in 3 cases at the primary site, while secondary lesions did not receive any treatment. The final results of our study were disappointing. All patients died of the tumor 6 to 24 months after the beginning of treatment (mean 11.9 months). Nevertheless, the survival time of the 4 patients with locally treated lesions was significantly longer than the one of 7 patients in whom the secondary lesions were not locally treated (18.2 vs 9.1 months; P<0.008). It should be noted that those patients simultaneously operated on two sites, the response to chemotherapy of "primary" and "secondary" lesions was always similar. This homogeneity supports the thesis that in synchronous multifocal osteosarcoma the tumors are not multicentric in origin but represent bone-to-bone metastases from a monocentric tumor.

Adolescent↗
PubMed2000

In vivo cytoreduction studies and cell sorting--enhanced tumor-cell detection in high-risk neuroblastoma patients: implications for leukapheresis strategies.

PURPOSE: To improve autologous leukapheresis strategies in high-risk neuroblastoma (NB) patients with extensive bone marrow involvement at diagnosis. PATIENTS AND METHODS: Anti-G(D2) immunocytochemistry (sensitivity, 1 in 10(5) to 10(6) leukocytes) was used to evaluate blood and bone marrow disease at diagnosis and during the recovery phase of the first six chemotherapy cycles in 57 patients with stage 4 NB and bone marrow disease at diagnosis. A total of 42 leukapheresis samples from the same patients were evaluated with immunocytology, and in 24 of these patients, an anti-G(D2) immunomagnetic enrichment step was used to enhance tumor-cell detection. RESULTS: Tumor cytoreduction was much faster in blood compared with bone marrow (3.2 logs after the first cycle and 2.1 logs after the first two cycles, respectively). Bone marrow disease was often detectable throughout induction, with a trend to plateau after the fourth cycle. By direct anti-G(D2) immunocytology, a positive leukapheresis sample was obtained in 7% of patients after either the fifth or sixth cycle; when NB cell immunomagnetic enrichment was applied, 25% of patients had a positive leukapheresis sample (sensitivity, 1 in 10(7) to 10(8) leukocytes). CONCLUSION: Standard chemotherapy seems to deliver most of its in vivo purging effect within the first four cycles. In patients with overt marrow disease at diagnosis, postponing hematopoietic stem-cell collection beyond this point may not be justified. Tumor-cell clearance in blood seems to be quite rapid, and earlier collections via peripheral-blood leukapheresis might be feasible. Immunomagnetically enhanced NB cell detection can be highly sensitive and can indicate whether ex vivo purging should be considered.

Adolescent↗
PubMed2000

Quantitative determination of sst2 gene expression in neuroblastoma tumor predicts patient outcome.

Neuroblastoma (NB) is the most common pediatric neuroendocrine tumor, and it is characterized by a quite variable clinical course. We previously found a great variability in the expression of somatostatin receptor type 2 (sst2) in several human NB cell lines and primary tumors. In this report we investigated whether expression of sst2 is somehow related to clinical outcome. We performed a retrospective study on 54 patients with a maximum follow-up of 100 months. The concentration of specific messenger ribonucleic acid (mRNA) for sst2 was measured by competitive RT-PCR and validated, in a small subset of samples, by quantitative imaging of gene (in situ hybridization) and protein (immunohistochemistry) expression. We found that sst2 mRNA was variably expressed in all NB tumors (range, 2.5 x 10(5) to 8 x 10(9) molecules/microg RNA) with a relevant reduction in the more advanced stage (P < 0.01). Analysis of Kaplan-Meier curves indicated that sst2 expression is positively related to the overall (P < 0.0001) and event-free (P < 0.0001) survival. Expression of sst2 was negatively related to tumor stage (P < 0.02) and MYCN amplification (P < 0.001), a poor prognostic factor. However, the prognostic information derived from sst2 is apparently independent from MYCN amplification, as assessed by stratifying sst2 values according to MYCN. In addition, the expression of sst2 was the only significant prognostic factor (P < 0.02) when it was included in a multivariate model containing other well known prognostic factors such as age, stage, and MYCN amplification. Hence, we propose that sst2 expression represents a new prognostic marker for NB. The main clinical value of a quantitative measure of sst2 lies in its ability to detect patients at low risk, independently from other prognostic factor, including MYCN amplification.

Brain Neoplasms↗
PubMed1999

Renin-angiotensin-aldosterone system in primary hyperparathyroidism before and after surgery.

Twenty consecutive unselected patients with proven primary hyperparathyroidism (PH), 26 essential hypertensive (EH) patients, and 13 normotensives were studied. Blood pressure (BP) and, under constant salt intake, plasma renin activity (PRA), parathyroid hormone (PTH), urinary and plasma sodium, potassium, aldosterone (ALD), creatinine, total calcium, and phosphate were measured. Patients with PH were also studied 1 and 6 months after successful surgery. In patients with PH, systolic and diastolic BP was significantly lower (P < .001) than in EH patients and higher (P < .005) than in controls. Eight patients with PH (40%) had BP levels greater than 140/90 mm Hg. PTH and plasma and urinary calcium in patients with PH were significantly (P < .01) higher than in controls, while PRA, ALD, phosphate, potassium, and sodium were superimposable in the three groups. PTH in patients with PH was weakly correlated with PRA (positively) and with plasma potassium (negatively) and was not associated with ALD, calcium, sodium, and BP levels. Surgery was followed by a significant reduction (P < .01) in PTH, calcium, and urinary phosphate and an increase (P < .02) in plasma phosphate, potassium, and sodium, whereas PRA, ALD, urinary potassium and sodium, and BP showed no change. In hypertensive patients with PH, PTH, PRA, and plasma and urinary ALD, calcium, and sodium did not differ from the values in normotensive PH patients, and variations in these humoral parameters after surgery were comparable in the two groups. In conclusion, our results show that hypertension is frequently associated with PH. However, the present data raise doubts about the assumption of a renin-mediated causal relationship between hyperparathyroidism and high BP. Indeed, as a unique finding in favor of the hypothesis of a stimulating role of PTH in renin secretion, we observed only a weak relation between PTH and PRA. Thus, unknown and/or unassessed factors related to parathyroid disease cannot be ruled out to explain the hypertension observed in some patients with PH.

Adult↗
PubMed1998

Endogenous digitalis-like factor and ouabain immunoreactivity in adrenalectomized patients and normal subjects after acute and prolonged salt loading.

The aim of our study was to evaluate whether adrenals are involved in the secretion of endogenous digitalis-like factor(s) with polarity similar to (or less than) that of ouabain (EDLF-1), and whether acute plasma volume expansion is a physiological releasing stimulus for this factor(s) in humans. For this purpose, we measured the concentration of this substance(s) by a human placenta radioreceptor assay (RRA) and by the Du-Pont-NEN ouabain-EIA (immunoreactive ouabain, I-Oua) in plasma C18-extracts of eight normotensives and six patients with bilateral adrenalectomy before and after acute salt loading (2 lt 0.9% NaCl/2 h). The study was repeated after 2 weeks of increased sodium intake (200 mEq/day). Under basal conditions, EDLF-1 by RRA and I-Oua were similar in adrenalectomized patients and in controls and were not significantly modified by saline infusion. After 15 days of high sodium intake, basal plasma EDLF-1 and I-Oua were not significantly different from prediet levels, both in adrenalectomized patients and controls and were likewise unaffected by saline loading. Saline infusion, by contrast, significantly (P < or = .05) suppressed hematocrit and PRA and increased ANP both in controls and in patients, either before or after prolonged high dietary sodium. Plasma aldosterone (ALD) was similarly reduced (P < .001) in controls and, as expected, was undetectable in adrenalectomized patients. Our data indicate that in adrenalectomized patients circulating levels of EDLF-1 and I-Oua are similar to those of controls and that, in both groups, acute saline loading before and after sodium repletion does not influence circulating levels of these compounds. These findings suggest that, at least in humans, adrenals are not the main source of endogenous digitalis-like factor(s) with polarity similar to (or less than) that of ouabain, and that plasma volume expansion may be not a sufficient stimulus for the release of this factor(s).

Adrenal Glands↗
PubMed1998

G-CSF serum pharmacokinetics during peripheral blood progenitor cell mobilization: neutrophil count-adjusted dosage might potentially improve mobilization and be more cost-effective.

The optimal dosing schedule of G-CSF for peripheral blood progenitor cell (PBPC) mobilization is still under investigation although many centers use 10 microg/kg/day in a single subcutaneous dose. However, G-CSF clearance increases with increasing absolute neutrophil count (ANC). Hence a G-CSF dosage adjusted to ANC might be a reasonable approach. We measured G-CSF trough serum levels by sandwich ELISA assay at different ANCs in eight patients undergoing treatment with filgrastim at 10 microg/kg/day in a single subcutaneous dose. A total of 26 samples were analyzed, and a strong correlation between increasing ANC and decreasing G-CSF levels was found by linear regression analysis (P < 0.0003, r2 = 0.4199). For ANC values above 5000/microl the trough serum levels, ie 24 h after administration, were consistently below the level that provides maximal clonogenic precursor stimulation in vitro (10 ng/ml). Serial serum G-CSF measurements performed in three patients at 0, 3, 6, 9 and 24 h after G-CSF administration, showed a reduction of the area under the curve (AUC) with increasing ANC. For an ANC of 20000/microl or greater, the G-CSF serum level fell under the maximal in vitro stimulation threshold of 10 ng/ml within 12 h. This preliminary pharmacokinetic data seems to suggest that an ANC-adjusted G-CSF dosing schedule might improve the design of PBPC mobilization regimens.

Adolescent↗
PubMed1998

Pediatric peripheral blood progenitor cell collection: haemonetics MCS 3P versus COBE Spectra versus Fresenius AS104.

BACKGROUND: An increasing number of apheresis machines are becoming available for peripheral blood progenitor cell (PBPC) collection in children. STUDY DESIGN AND METHODS: At the Children's Hospital of Florence (Italy), three apheresis machines were evaluated: MCS 3P (Haemonetics) (10 procedures in 4 patients, aged 10-12 years, weight 23.5-64 kg), Spectra, (COBE) (8 procedures in 3 patients, aged 4-17 years, weight 19-59 kg), and AS104 (Fresenius) (24 procedures in 9 patients, aged 2-16 years, weight 13.6-60 kg). For PBPC quantitative analysis, CD34 cytofluorimetry was employed. Relevant variables analyzed included efficiency of CD34+ cell extraction and enrichment, mononuclear cell purity and red cell contamination of the apheresis components, and platelet count decreases after leukapheresis. RESULTS: No significant differences in CD34+ cell-extraction abilities were found. However, the AS104 provided consistently purer leukapheresis components in terms of mononuclear cell and CD34+ cell enrichment (441 +/- 59%, vs. 240 +/- 35% and 290 +/- 42% for MCS 3P and Spectra, respectively). Postapheresis platelet counts dropped the least with the AS104. The smallest patient who underwent apheresis with MCS 3P (the only machine working on discontinuous flow and hence with greater volume shifts) weighed 23.5 kg and tolerated the procedure well, with no signs of hemodynamic instability. No significant complications were observed. CONCLUSION: All machines seem to have comparable PBPC extraction efficiency, but the AS104 seems to give the component with the greatest PBPC enrichment. This feature might be relevant for further ex vivo cell processing (CD34+ cell selection, expansion, and so on).

Adolescent↗
PubMed1998

Neoadjuvant chemotherapy for extremity osteosarcoma--preliminary results of the Rizzoli's 4th study.

A neoadjuvant chemotherapy protocol (1/93-1/95) for extremity osteosarcoma preoperatively using high-dose methotrexate (HDMTX) as single agent per cycle and three different combinations of other drugs (CDP/IFO,CDP/ADM,IFO/ADM) is reported. The four drugs were used postoperatively as single agents. Treatment was uniform, but suspended earlier if total necrosis was attained. An improvement was found in the results of the previous study using only IFO postoperatively, with 16/119 patients (97%) avoiding amputation, and 38 (32%) attaining complete necrosis. At a 3-year (2-4 years) mean follow-up, 92 patients (76%) remained continuously disease-free, 2 died of chemotherapy-related toxicity and 25 suffered relapse. Projected 3-year DFS also improved (75% vs. 60%; p = 0.04). Despite limb salvage, local recurrences (6.3%) and infections were few, although postoperative chemotherapy was restarted within a week. Therefore, until new effective drugs are found, expertise in using the four known drugs may improve cure rate and help to avoid amputation in almost all patients.

Adolescent↗
PubMed1998

Conn syndrome: 14 year's experience from two European centres.

OBJECTIVE: To evaluate the long term results of adrenalectomy for primary hyperaldosteronism. DESIGN: Multicentre retrospective cohort study. SETTING: Two university hospitals, UK and Italy. SUBJECTS: 55 patients who presented with a mean (SD) preoperative blood pressure of 181/110 (21/10) mmHg and a mean (SD) potassium of 2.8 (0.4) mmol/L (range 1.6-4) during the period October 1978 to October 1992. INTERVENTIONS: Unilateral adrenalectomy, usually by the extraperitoneal approach. Adrenalectomy was total in all but nine cases. MAIN OUTCOME MEASURES: Accuracy of preoperative investigations for the diagnosis and localisation of the lesions, histology, morbidity and mortality, long term outcome (mean follow up 8.8 years). RESULTS: Computed tomography gave a diagnostic accuracy for unilateral lesions of 88%, the postural stimulation test 80%, norcholesterol scintigraphy 84%, and ultrasonography 57%. Histological examination showed carcinoma (n = 1), diffuse hyperplasia (n = 2), nodular hyperplasia (n = 11) including 5 with macronodular hyperplasia, double adenoma (n = 1) and single adenoma (n = 40). No patient died, and 10 developed minor complications. At the latest follow-up 44/52 patients with benign unilateral lesions (85%) have been cured by adrenalectomy. CONCLUSIONS: Our results confirm the safety of the extraperitoneal approach, and suggest that the improvement in the accuracy of preoperative investigations has allowed a careful selection of patients with the consequent amelioration of the long term outcome of surgery for Conn's syndrome. As laparoscopic adrenalectomy is currently advocated as the operation of choice for surgically-remediable mineralocorticoid excess, its long term results will have to be comparable with these standards.

Adrenalectomy↗
PubMed1998

High-sensitivity immunocytologic analysis of neuroblastoma cells in paired blood and marrow samples.

High-sensitivity immunocytochemistry was used to evaluate the relative frequency of neuroblastoma cells in bone marrow and peripheral blood in patients with neuroblastoma (NB). A total of 51 concomitant paired blood and marrow samples (102 total) from 35 patients with NB (age 4 months-31 years; stage 29 stage IV, 4 stage III, 2 stage IVS; 14 at diagnosis, 18 in relapse, 12 during treatment, and 7 off-therapy) were analyzed. Cytospins containing up to 10(6) cells each were prepared using the mononuclear cell (MNC) fraction. For immunocytologic staining, a primary mouse monoclonal anti-GD2 antibody (3F8), a secondary antimouse biotinylated antibody, and a streptavidin-alkaline phosphatase complex were used. A minimum of two cytospins containing a mean of 1.4 x 10(6) total MNCs was analyzed in addition to a negative and a positive control. No circulating tumor cells were detected when the concomitant marrow samples were negative or had <10 positive cells per 106 MNC (23 of 51 samples). Of the 18 marrow samples positive at 10-10,000 cells per 106 MNC, 6 had detectable NB cells in the corresponding blood sample, whereas for marrow samples with >10,000 NB cells per 10(6) MNC (1%), the concomitant blood sample was positive for 9 of the 10. When both marrow and blood samples were positive (15 BM-PB pairs), NB cell frequency was significantly lower in blood, with a mean difference of 2.14 logs (median 2.22, range -0.16-4.8, standard error 0.38). In patients with NB, circulating tumor cell frequencies seem to be substantially lower than in concomitant marrow samples, with a mean difference of >2 logs.

Adolescent↗
PubMed1998

Endothelial dysfunction in hypertension is independent from the etiology and from vascular structure.

The aim of our study was to evaluate the relationships between endothelial function, small resistance artery structure, and blood pressure in patients with primary or secondary hypertension. Sixty subjects were included in the study: 9 patients with pheochromocytoma, 10 with primary aldosteronism, 17 with renovascular hypertension, and 13 with essential hypertension with 11 normotensive subjects who served as controls. Clinic and 24-hour ambulatory blood pressure (ABPM) were evaluated. All subjects were submitted to a biopsy of subcutaneous fat. Small resistance arteries were dissected and mounted on a micromyograph and the media/lumen ratio was calculated. A dose-response curve to acetylcholine was performed at cumulative concentrations from 10(-9) to 10(-5) mol/L. The vasodilator response to acetylcholine was similarly impaired in the four groups of hypertensive patients (ANOVA P<.05 versus normotensive controls), without any significant difference among them. In subcutaneous small arteries of patients with either primary aldosteronism or renovascular hypertension, a marked increase in media:lumen ratio was observed, while in patients with pheochromocytoma, the extent of vascular structural alterations was similar to that observed in essential hypertension. No significant correlation between media-lumen ratio or clinic blood pressure and maximum acetylcholine-induced vasodilatation was observed. On the contrary, a significant, albeit not very close, correlation between ABPM values and maximum acetylcholine-induced vasodilatation was observed (r=34, P<.05 with 24-hour systolic blood pressure, r=0.36, P<.05 with 24-hour diastolic blood pressure). In conclusion, endothelial dysfunction seems to be independent from the degree of vascular structural alterations and from the etiology of hypertension, and it is probably more linked to the hemodynamic load.

Acetylcholine↗
PubMed1997

Endogenous estrogen and acetylcholine-induced vasodilation in normotensive women.

Acute exogenous estrogen administration enhances endothelial function in postmenopausal women. To evaluate the effect of endogenous estrogen on endothelium-dependent vasodilation, in 10 fertile normotensive women (age range 45 to 51 years) we studied the changes in forearm blood flow (strain-gauge plethysmography) induced by intrabrachial acetylcholine (0.15, 0.45, 1.5, 4.5, 1.5 micrograms.100 mL-1.min-1), an endothelium-dependent vasodilator, or sodium nitroprusside (1, 2, 4 micrograms.100 mL-1.min-1), an endothelium-independent vasodilator, in basal conditions and within 1 month after ovariectomy. As control subjects, 10 matched healthy women were also evaluated. In basal condition, vasodilation to acetylcholine and sodium nitroprusside was similar in patients and control subjects. Ovariectomy was followed by endogenous estrogen deprivation (from 71.6 +/- 31.3 to < 12 pg/mL) and was associated with a significant (P < .01) reduction in acetylcholine-induced vasodilation compared with baseline (maximum percent increase in forearm blood flow: baseline 568.2 +/- 47.1%; ovariectomy 309.5 +/- 37.4%); the response to sodium nitroprusside was unaffected by ovariectomy (maximum percent increase in forearm blood flow: baseline 526.4 +/- 36.5%; ovariectomy 454.7 +/- 47.2%; P = NS). In 6 of 10 patients, the study was repeated after 3 months of estrogen replacement therapy (17 beta-estradiol, 50 micrograms/d by transdermal patches). Exogenous estrogen restored acetylcholine-induced vasodilation (maximum percent increase in forearm blood flow: 548.9 +/- 43.1%; P < .01 versus ovariectomy), which was no longer different from baseline, whereas the response to sodium nitroprusside was not affected (maximum percent increase in forearm blood flow: 480.2 +/- 39.3%; P = NS). These results suggest a protective role of endogenous estrogen on endothelium-dependent vasodilation in the forearm vascular bed of normotensive women.

Acetylcholine↗
PubMed1997

Imaging of somatostatin receptors by indium-111-pentetreotide correlates with quantitative determination of somatostatin receptor type 2 gene expression in neuroblastoma tumors.

We reported previously that the relative level of gene expression for sst2, a subtype of somatostatin receptors, was positively related to patient outcome in the childhood tumor neuroblastoma (NB). Because sst2 binds with high-affinity octreotide and its scintigraphic derivative, 111In-pentetreotide, we tested the hypothesis of whether NB tumor imaging with 111In-pentetreotide gives similar information to ex vivo measurement of sst2 expression. We, therefore, studied simultaneously nine NB tumors with 111In-pentetreotide single photon emission computed tomography and competitive reverse transcription-PCR for sst2, along with other prognostic markers. To quantitate the relative abundance of 111In-pentetreotide binding to NB tumors, we developed a simple semiquantitative method, based on the mathematical analysis of 111In-pentetreotide association to cancer cell receptors at different time points (4 and 24 h). We indeed found that the ratio between the activity in a manually extracted region of interest from pathological (ROIT) and background (ROINT) area was increasing between early and late acquisition only in affected tissues. The rate of this pathological increase was quite different among patients and significantly (P < 0.01) related to the abundance of sst2 gene expression, as measured by competitive reverse transcription-PCR on ex vivo tumor samples. Because we demonstrated that in 26 NB patients the density of sst2 is strongly related to survival (P < 0.0005) and apparently independent from N-myc oncogene amplification (P < 0.05), we propose that NB tumor imaging with 111In-pentetreotide may have not only a diagnostic but also a prognostic value.

Adolescent↗