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Biomedical subjects

C Barone

Publications and source records attributed to C Barone.

At least 37 records · Page 2Linked to original sources
PubMed1998

Rotavirus disease, but not infection and development of intestinal histopathological lesions, is age restricted in rabbits.

The rabbit model of rotavirus infection has proved to be useful for assessing active immunity and protection after infection or vaccination with virus or virus-like particles. One limitation of the rabbit model is that after experimental infection of rabbits, clinical diarrhea is not routinely induced. Lack of diarrhea in the rabbit model has been proposed to be due to the fluid absorptive capability of the cecum or attenuation of virus strains through tissue culture adaptation. To test whether a wild-type lapine rotavirus strain BAP (BAPwt) isolated from diarrheic rabbits would cause disease on passage in rabbits, 1-, 2-, 10-, and 16-week-old rabbits were orally inoculated with BAPwt, its tissue culture-adapted counterpart strain (BAP-2), tissue culture-adapted lapine strain ALA, or PBS. Lapine rotavirus infection in 1-week-old, but not >/=2-week-old, rabbits resulted in the development of disease characterized by soft, wet, yellow-to-brownish-green partially formed-to-liquid stools observed only at the time of virus antigen shedding. The level and duration of virus shedding after infection were prolonged in 1-week-old rabbits compared with rabbits >/=2 weeks of age. Although diarrhea was not observed beyond the first 2 weeks of life, histopathological changes, including villus shortening and fusion, increased vacuolation of epithelial cells, and mononuclear infiltration of the lamina propria, were observed throughout the small intestine between 12 and 120 h after ALA infection in 1-week-old, 1- to 2-month-old, and 11-month-old rabbits. In 11-month-old rabbits, onset of intestinal damage appeared to be slightly delayed, was less severe, and was not observed in the duodenum. There were no differences in the immune responses to rotavirus infection in rabbits of different age groups (1 week to 5 years of age). All lapine rotavirus-inoculated rabbits seroconverted and were protected from virus challenge at 28 days postinoculation. Like in mice, rotavirus disease is age restricted in rabbits.

Aging↗
PubMed1998

Treatment of patients with advanced gastric carcinoma with a 5-fluorouracil-based or a cisplatin-based regimen: two parallel randomized phase II studies.

BACKGROUND: Although many drug combination therapies have been proposed, there is no standard therapy for patients with advanced gastric carcinoma. The superiority of combination therapy over monochemotherapy has not been demonstrated convincingly. To explore the role of monochemotherapy, the authors evaluated 5-fluorouracil (5-FU), modulated by 6S-leucovorin (6S-LV) and a cisplatin-containing regimen, which was comprised of epirubicin, etoposide, and cisplatin with the addition of the reversal agent lonidamine (EEP-L). METHODS: After stratification according to performance status (PS) and resection of the primary tumor, 72 patients with advanced gastric carcinoma were randomized to 2 parallel Phase II trials with 5-FU/6S-LV and EEP-L, respectively. Thirty-six patients in Study A received bolus 6S-LV, 100 mg/m2, followed by bolus 5-FU, 370 mg/m2, on Days 1-5 and 36 others in Study B received epirubicin, 30 mg/m2, on Days 1 and 5; etoposide, 100 mg/m2, on Days 1, 3, and 5; cisplatin, 30 mg/m2, on Days 2 and 4; and lonidamine, 150 mg/day. RESULTS: There were 6 partial responses (18.2%) (95% confidence interval [CI] +/- 13.2) in Study A and 7 partial responses (21.9%) (95% CI +/- 14.3) in Study B. Partial responses were more frequent in patients with resected tumors or with an Eastern Cooperative Oncology Group PS of 0-1. The median duration of response was 8.8 and 8.3 months, respectively, in Study A and Study B. The median survival reached 8 months in Study A and 9 months in Study B. In the whole population of patients survival was significantly higher in patients with a PS of 0-1 (P < 0.05). Patients with a PS of 0-1 and a resected tumor had the significantly longest survival both in EEP-L treated patients and in all evaluable patients in the two studies. The most frequent World Health Organization Grade 3-4 toxic effects were gastrointestinal in Study A and hematologic in Study B. No treatment-related death was observed. CONCLUSIONS: The efficacy of 5-FU, modulated with 6S-LV, is moderate in patients with advanced gastric carcinoma, similar to cisplatin-containing regimens. PS and other prognostic factors could influence the response rate, which does not appear to be a reliable parameter for evaluating the outcome of chemotherapy trials.

Adult↗
PubMed1998

A phase II study of irinotecan alternated with five days bolus of 5-fluorouracil and leucovorin in first-line chemotherapy of metastatic colorectal cancer.

PURPOSE: This multicenter phase II study was designed to assess the efficacy of the alternating schedule of irinotecan (CPT-11) with bolus 5-fluorouracil (5-FU) and leucovorin (LV) in first-line chemotherapy for metastatic colorectal cancer (CRC). PATIENTS AND METHODS: Patients with histologically proven metastatic colorectal cancer, and at least one bidimensionally measurable lesion, aged 18-70, with performance status < or = 2, normal baseline biological values and no prior chemotherapy (or only adjuvant chemotherapy completed > or = 6 months before study entry) were selected. Treatment was irinotecan 350 mg/m2, i.v., day 1, alternating with leucovorin 20 mg/m2 i.v. and 5-FU 425 mg/m2, i.v. daily for five consecutive days, day 22-26 (Mayo Clinic regimen). One alternating cycle was to be performed every six weeks. Patients were evaluated for efficacy every alternating cycle. Treatment was administered until five alternating cycles, disease progression, unacceptable toxicity or patient refusal. RESULTS: Thirty-three patients (28 chemotherapy-naïve and five with prior adjuvant treatment completed > 1 year prior to accrual) were enrolled. The objective response rate (RR) was 30% (95% CI: 16-49; 10 patients/33; nine partial response and one complete response). All responses were reviewed by an independent external review committee. An additional 49% of patients had stable disease. The median survival was 16 months, the one year survival amounted to 58% and the median progression free survival was 7.2 months. Relative dose intensity was nearly 90% for both drugs. Grade 3-4 diarrhea and neutropenia were the most frequent severe toxic events, seen in 24% and 64% of patients, respectively. CONCLUSIONS: The alternating schedule of CPT-11 350 mg/m2 with five days bolus of 5-FU and low dose LV is an active and feasible regimen as front-line therapy for metastatic CRC. It is well tolerated, without evidence of overlapping toxicity. The response rate appears promising with regard to that expected with either single agent. This regimen warrants further assessment in randomized trials.

Adult↗
PubMed1998

An ecologically differentiated, multifactor model of adolescent network orientation.

The paper presents a test of an ecologically differentiated model of social network orientation for adolescents that distinguished between different social network reference groups (family, peers, and nonfamily adults). The model was tested in two consecutive studies. Study 1 describes initial model development (N = 120). Study 2 presents a confirmatory factor analysis with a second sample (N = 430) to replicate the factor structure developed in Study 1. Results supported a three-factor model of network orientation that differentiated between network reference groups. Analyses of concurrent and predictive validity indicated that orientation to network reference groups was differentially related to the perceived quality and frequency of support from members of respective social network groups. Group differences (gender, race) regarding network orientation to different network reference groups were consistent with studies of other social network processes. Implications for the study of the network orientation and the study of social networks more generally are discussed.

Adaptation, Psychological↗
PubMed1998

Quantitative analysis of basic fibroblast growth factor and vascular endothelial growth factor in human colorectal cancer.

Tumour growth is angiogenesis dependent. Some authors suggest a prognostic role of microvessel count in colorectal cancer. We tested the role of basic fibroblast growth factor (bFGF) and vascular endothelial growth factor (VEGF) in the switch to the angiogenic phenotype in 35 patients with colorectal cancer at different stages of disease. We evaluated the two angiogenic factors, by enzyme-linked immunosorbent assay (ELISA), in tumour, peritumoral mucosa, pathological mesenteric and peripheral blood. We used ten endoscopic intestinal biopsies and ten peripheral blood samples from healthy subjects as control. bFGF was significantly lower in tumour tissues and in peritumoral mucosas than in healthy mucosas, whereas VEGF was up-regulated in tumours but not in peritumoral mucosa. Both angiogenic factors were greatly increased in mesenteric blood. VEGF tumour and serum levels were significantly correlated with the stage of disease. bFGF tumour and serum concentration were not correlated with the stage of disease. The high levels of bFGF in mesenteric blood suggest that this growth factor might be abnormally released from tumour tissue and peritumoral mucosa and could function as an early effector in the switch to the angiogenic phenotype. In contrast, VEGF, whose levels show a significant correlation with the stage of disease, could act in a following step, supporting tumour progression.

Adult↗
PubMed1998

Subunit rotavirus vaccine administered parenterally to rabbits induces active protective immunity.

Virus-like particles (VLPs) are being evaluated as a candidate rotavirus vaccine. The immunogenicity and protective efficacy of different formulations of VLPs administered parenterally to rabbits were tested. Two doses of VLPs (2/6-, G3 2/6/7-, or P[2], G3 2/4/6/7-VLPs) or SA11 simian rotavirus in Freund's adjuvants, QS-21 (saponin adjuvant), or aluminum phosphate (AlP) were administered. Serological and mucosal immune responses were evaluated in all vaccinated and control rabbits before and after oral challenge with 10(3) 50% infective doses of live P[14], G3 ALA lapine rotavirus. All VLP- and SA11-vaccinated rabbits developed high levels of rotavirus-specific serum and intestinal immunoglobulin G (IgG) antibodies but not intestinal IgA antibodies. SA11 and 2/4/6/7-VLPs afforded similar but much higher mean levels of protection than 2/6/7- or 2/6-VLPs in QS-21. The presence of neutralizing antibodies to VP4 correlated (P < 0.001, r = 0.55; Pearson's correlation coefficient) with enhanced protection rates, suggesting that these antibodies are important for protection. Although the inclusion of VP4 resulted in higher mean protection levels, high levels of protection (87 to 100%) from infection were observed in individual rabbits immunized with 2/6/7- or 2/6-VLPs in Freund's adjuvants. Therefore, neither VP7 nor VP4 was absolutely required to achieve protection from infection in the rabbit model when Freund's adjuvant was used. Our results show that VLPs are immunogenic when administered parenterally to rabbits and that Freund's adjuvant is a better adjuvant than QS-21. The use of the rabbit model may help further our understanding of the critical rotavirus proteins needed to induce active protection. VLPs are a promising candidate for a parenterally administered subunit rotavirus vaccine.

Adjuvants, Immunologic↗
PubMed1998

Analysis of host range restriction determinants in the rabbit model: comparison of homologous and heterologous rotavirus infections.

The main limitation of both the rabbit and mouse models of rotavirus infection is that human rotavirus (HRV) strains do not replicate efficiently in either animal. The identification of individual genes necessary for conferring replication competence in a heterologous host is important to an understanding of the host range restriction of rotavirus infections. We recently reported the identification of the P type of the spike protein VP4 of four lapine rotavirus strains as being P[14]. To determine whether VP4 is involved in host range restriction in rabbits, we evaluated infection in rotavirus antibody-free rabbits inoculated orally with two P[14] HRVs, PA169 (G6) and HAL1166 (G8), and with several other HRV strains and animal rotavirus strains of different P and G types. We also evaluated whether the parental rhesus rotavirus (RRV) (P5B[3], G3) and the derived RRV-HRV reassortant candidate vaccine strains RRV x D (G1), RRV x DS-1 (G2), and RRV x ST3 (G4) would productively infect rabbits. Based on virus shedding, limited replication was observed with the P[14] HRV strains and with the SA11 Cl3 (P[2], G3) and SA11 4F (P6[1], G3) animal rotavirus strains, compared to the homologous ALA strain (P[14], G3). However, even limited infection provided complete protection from rotavirus infection when rabbits were challenged orally 28 days postinoculation (DPI) with 10(3) 50% infective doses of ALA rabbit rotavirus. Other HRVs did not productively infect rabbits and provided no significant protection from challenge, in spite of occasional seroconversion. Simian RRV replicated as efficiently as lapine ALA rotavirus in rabbits and provided complete protection from ALA challenge. Live attenuated RRV reassortant vaccine strains resulted in no, limited, or productive infection of rabbits, but all rabbits were completely protected from heterotypic ALA challenge. The altered replication efficiency of the reassortants in rabbits suggests a role for VP7 in host range restriction. Also, our results suggest that VP4 may be involved in, but is not exclusively responsible for, host range restriction in the rabbit model. The replication efficiency of rotavirus in rabbits also is not controlled by the product of gene 5 (NSP1) alone, since a reassortant rotavirus with ALA gene 5 and all other genes from SA11 was more severely replication restricted than either parental rotavirus strain.

Animals↗
PubMed1998

Effect of acute and chronic administration of tamoxifen on GH response to GHRH and on IGF-I serum levels in women with breast cancer.

Tamoxifen, an estrogen antagonist, is usually employed in the treatment of breast cancer. Its mechanism of action is not well known because an antiproliferative effect of the drug has been shown also in estrogen receptor negative tumors, most likely mediated by the inhibition of local growth factors and particularly IGF-I. However, the action of tamoxifen on the GH-IGF-I axis is still open to investigation. We have investigated the influence of acute and chronic treatment with tamoxifen on GH response to GHRH and IGF-I serum levels in six postmenopausal women with metastatic breast cancer. A GHRH test (50 microg i.v. at time 0, GH determinations at 0, 15, 30, 60, 90 and 120 min) was performed (a) basally, (b) 3 h after 40 mg oral administration of tamoxifen and (c) after 8 weeks of 20 mg twice a day oral tamoxifen treatment. IGF-I was measured basally and after chronic tamoxifen therapy. No significant modifications in GH response to GHRH were observed after acute or chronic treatment with tamoxifen vs the basal test. On the contrary, chronic tamoxifen treatment induced a significant decrease in serum IGF-I levels. Basal pretreatment levels of 123+/-18 microg/l were suppressed to 65+/-11 microg/l (mean suppression 47%, P < 0.001). These preliminary data confirm the inhibitory effect of tamoxifen on IGF-I production but seem to exclude the possibility that this effect may be due to an inhibition of GH secretion.

Aged↗
PubMed1998

[New developments in the treatment of medullary thyroid carcinoma].

Medullary thyroid carcinoma arises from the C cells, which produce a characteristic hormone, calcitonin. At present, surgery is the main treatment modality. Medullary thyroid carcinoma is usually treated with total thyroidectomy and with removal of nodes in the central portion of the neck and upper mediastinum. Cervical nodes dissection may be required for cancers affecting lateral neck nodes. Substitutive therapy with levo-thyroxine is indicated after surgery. External beam radiation therapy is not effective against advanced medullary thyroid carcinoma, while chemotherapy has a marginal activity. Biological therapy induces its anti-tumour activity through the inhibition of tumour cell growth without cytolysis and stimulating the antitumour immune response, in the absence of relevant side effects. On these bases, it can be suggested that chemo-refractory tumours could be still responsive to biological agents. In the last years somatostatin analogues and interferon have been used in the therapy of advanced and symptomatic medullary thyroid carcinoma, demonstrating an efficacious effect on neuroendocrine symptoms and on the production of calcitonin and an improving in quality of life. Even if there are no consistent data on the effects of biological agents on the reduction of tumour mass, the combined use of chemotherapy and biological therapy needs to be experimented in medullary thyroid carcinoma.

Carcinoma, Medullary↗
PubMed1998

[Colovesical fistulae as a complication of diverticula: a report of 2 cases].

The authors report two cases of colovesical fistula as a complication of diverticular disease. They underline the increasing frequency of this complication, although the less frequent one. They also stress the importance of clinical and instrumental examinations that are several and among which TC scan can be crucial for surgical treatment. The therapy, exclusively surgical, can be made in one or two steps, according to patient status.

Aged↗
PubMed1997

A 3-19-year follow-up study on diabetic retinopathy in patients diagnosed in childhood and treated with conventional therapy.

Few data are available from follow-up studies on diabetic retinopathy in patients diagnosed with insulin-dependent (Type 1) diabetes mellitus in childhood and treated with conventional therapy. We report the results of conventional insulin therapy on development of diabetic retinopathy in 100 children and adolescents (47 females and 53 males), aged 8.3 +/- 3.5 (1.2-16.4) years at diagnosis of disease. Oral or intravenous fluorescein angiography was performed during a 3-19 year follow-up in all patients. Retinopathy was staged according to the criteria of the Italian Society of Diabetology (SID). During follow-up, retinopathy was observed in 28 patients (28%). At the end of follow-up, retinopathy was present in 23 patients and had disappeared in 5. Life-table analysis showed a median disease-free interval of 10.8 years. At 10 years from diagnosis the percentage of patients free of retinopathy was 66%. Poor metabolic control, age, and degree of pubertal development at diagnosis were the most important risk factors.

Age Factors↗
PubMed1997

Ambulatory blood pressure monitoring: how reproducible is it?

We tested the reproducibility of ambulatory blood pressure monitoring (ABPM) by the use of agreement plots. Thirty-two normotensive volunteers underwent ABPM on four separate days (interval 28 days), on the same typical weekday. Sleeping time was restricted to the ABPM nighttime subperiod from 11:00 PM to 7:00 AM. Twenty-four-hour average values-both systolic and diastolic-daytime average values, and nighttime average values, as well as standard deviation (SD) values, were analyzed for differences (analysis of variance). Adaptation occurred from the first to the fourth ABPM, ie, average 24 h, daytime, and nighttime values were lower (-1 to -3 mm Hg) during the fourth recording than the first (P < .05 to P < .01). The agreement analysis showed a surprisingly high agreement among the four data sets (ie, differences from +/-2.54 to +/-5.92 mm Hg; +/-2 SD of the distribution). We concluded that reproducibility of ABPM seems excellent, but adaptation may occur, even in normotensive volunteers under research conditions. Caution must be paid before labeling a patient as hypertensive, because initial ABPM may yield higher values than later monitorings.

Adult↗
PubMed1997

Peritoneal mesothelioma in recurrent familial peritonitis.

A 39-year-old man had a 2-year history of fatigue, weight loss, drug-resistant ascites, and decreased intestinal motility. During adolescence he began to suffer frequent episodes of acute benign peritonitis that spontaneously subsided at age 35. The fact that his younger brother was taking colchicine for the same symptoms led us to diagnose familial Mediterranean fever (FMF). The medical workup revealed uniform thickening of the intestinal wall with no signs of amyloidosis. Exploratory laparotomy revealed diffuse peritoneal mesothelioma that proved to be unresponsive to chemotherapy. There was no history of asbestos exposure. It is probable that the chronic peritoneal inflammation was responsible for the development of this tumor, although in almost all cases of FMF this phenomenon causes only limited peritoneal fibrosis or, less commonly, encapsulating peritonitis. A computerized search of the literature indicates that this is the second report of peritoneal mesothelioma associated with FMF.

Adult↗
PubMed1997

[Retroperitoneal tumors: personal experience].

The Authors experience in five retroperitoneal tumors with symptoms and histopathological characteristics not different from those described in the Literature, is here reported. Topographic findings, classification, and incidence of retroperitoneal tumors as referred by various Authors are discussed. Two aspects are particularly pointed out: the histological type and the surgical strategy for their removal. Concerning the first aspect, the Authors underline that benign lesion may have an optimal outcome and a long survival, unlike the malignant ones, which have always unfavourable prognosis, despite adjuvant and complementary therapy (radiotherapy, chemotherapy). As for the second aspect, surgery is the treatment of choice even when other organs different from those exclusively retroperitoneal, may be involved in the demolition.

Adult↗
PubMed1996

Rotavirus subunit vaccines.

We evaluated rotavirus subunit vaccines for use in humans and animals. Insect cells were co-infected with combinations of individual baculovirus recombinants expressing human, bovine or simian rotavirus VP2, VP4, VP6 or VP7 to produce virus-like particles (VLPs). To determine whether immunization with VLPs could induce active protective immunity, VLPs were administered parenterally to rabbits, and the immune response and protection from rabbit ALA rotavirus challenge were evaluated. Complete or partial protection was attained, showing that parenteral immunization with VLPs induces active protective immunity. We also examined whether heterotypic immune responses could be induced with a limited number of broadly reactive VP7 proteins or with chimeric particles (multiple VP7 types on individual particles). The feasibility of this approach was determined by immunizing mice with VLPs containing a G3 VP7 or G1 VP7 and chimeric G1/G3 VLPs. Broadly reactive neutralizing antibody was induced by the G1 VLPs. VLPs also have been successfully used to boost lactogenic (colostral and milk) immunity in dairy cows. Taken together, these results show that VLPs can be effective immunogens in rabbits, mice and dairy cattle when administered parenterally, a limited number of VLPs may be sufficient to produce a broadly protective vaccine, and G3 VLPs may serve as an effective subunit vaccine for use in bovines.

Animals↗