Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 285
Filtrar
1.
Diabetes Obes Metab ; 12(10): 871-5, 2010 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-20920039

RESUMO

BACKGROUND: We have recently shown that intranasal administration of mouse [D-Leu-4]-OB3 reconstituted in Intravail(®) to male Swiss Webster mice resulted in significantly higher uptake and bioavailability when compared with commonly used injection methods of delivery. AIM AND METHODS: In this study, we examined the effects of intranasal delivery of mouse [D-Leu-4]-OB3 in Intravail(®) on energy balance, glucose regulation, insulin secretion and serum levels of osteocalcin, a specific and sensitive marker of bone formation. Genetically obese C57BLK/6-m db/db mice were allowed food and water ad libitum and given either Intravail(®) alone or mouse [D-Leu-4]-OB3 in Intravail(®) for 14 days by intranasal instillation. RESULTS: Mouse [D-Leu-4]-OB3 reduced body weight gain, daily food intake, daily water intake and serum glucose by 11.5, 2.2, 4.0 and 61.9%, respectively. Serum insulin levels in db/db mice given mouse [D-Leu-4]-OB3 were approximately threefold lower than those in mice receiving Intravail(®) alone. Mouse [D-Leu-4]-OB3 elevated serum osteocalcin in db/db mice by 28.7% over Intravail(®) treated control mice. CONCLUSIONS: The results of our study indicate that intranasal delivery of biologically active mouse [D-Leu-4]-OB3 in Intravail(®) is feasible and has significant effects on regulating body weight gain, food and water intake, serum glucose, insulin sensitivity and bone formation in leptin-resistant C57BLK/6-m db/db mice.


Assuntos
Glicemia/efeitos dos fármacos , Metabolismo Energético/efeitos dos fármacos , Insulina/metabolismo , Leptina/farmacocinética , Osteogênese/efeitos dos fármacos , Fragmentos de Peptídeos/farmacologia , Administração Intranasal , Animais , Disponibilidade Biológica , Secreção de Insulina , Leptina/administração & dosagem , Leptina/farmacologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Obesos , Fragmentos de Peptídeos/administração & dosagem , Fragmentos de Peptídeos/farmacocinética
2.
Diabetes Obes Metab ; 12(6): 532-9, 2010 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-20518808

RESUMO

BACKGROUND: We have recently shown that intranasal administration of mouse [d-Leu-4]-OB3 reconstituted in Intravail to male Swiss Webster mice resulted in significantly higher bioavailability than commonly used injections methods of delivery. The absorption profile associated with intranasal delivery of mouse [d-Leu-4]-OB3 showed an early peak representing absorption across the nasal mucosa, and a later peak suggesting a gastrointestinal site of uptake. AIM AND METHODS: In the present study, we examined the effects of orally administered (by gavage) mouse [d-Leu-4]-OB3 on energy balance, glycaemic control and serum osteocalcin levels in male C57BL/6J wild-type and ob/ob mice allowed food and water ad libitum or calorie restricted by 40% of normal intake. RESULTS: In wild-type mice fed ad libitum, oral delivery of mouse [d-Leu-4]-OB3 reduced body weight gain, food intake and serum glucose, by 4.4, 6.8 and 28.2% respectively. Serum osteocalcin levels and water intake were essentially the same in control and treated wild-type mice. In ob/ob mice fed ad libitum, mouse [d-Leu-4]-OB3 reduced body weight gain, food intake, water intake and serum glucose by 11.6, 16.5, 22.4 and 24.4% respectively. Serum osteocalcin in ob/ob mice treated with mouse [d-Leu-4]-OB3 was elevated by 62% over controls. Calorie restriction alone caused significant weight loss in both wild-type (9.0%) and ob/ob (4.8%) mice, and mouse [d-Leu-4]-OB3 did not further enhance this weight loss. As expected, serum glucose levels in wild-type and ob/ob mice were significantly reduced by calorie restriction alone. Mouse [d-Leu-4]-OB3 further reduced serum glucose in wild-type mice and normalized levels in ob/ob mice. Calorie restriction alone reduced serum osteocalcin levels by 44.2% in wild-type mice and by 19.1% in ob/ob mice. Mouse [d-Leu-4]-OB3 prevented this decrease in groups of mice. CONCLUSIONS: The results of this study suggest that oral delivery of mouse [d-Leu-4]-OB3 in Intravail is possible and may have potential not only as an alternative therapy in the treatment of human obesity and some of its associated metabolic dysfunctions, but also may help to prevent and/or reverse at least some of the bone loss which accompanies osteoporosis, anorexia nervosa and other wasting diseases.


Assuntos
Glicemia/efeitos dos fármacos , Leptina/administração & dosagem , Osteocalcina/sangue , Fragmentos de Peptídeos/administração & dosagem , Administração Oral , Animais , Metabolismo Energético/efeitos dos fármacos , Leptina/farmacologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Obesos , Fragmentos de Peptídeos/farmacologia
3.
J Cardiovasc Surg (Torino) ; 43(4): 441-7, 2002 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-12124549

RESUMO

BACKGROUND: To evaluate oxidative stress and myocardial damage after aortic crossclamping release (ACCR) during cardio pulmonary bypass (CPB) in children two parameters were investigated: total glutathione (GSH) and its oxidoreductive reactions (GSH/GSSG) as expression of oxidative stress, and plasmatic turnover of myocardial taurine (TAU) as expression of cell damage. METHODS: The study was divided in two periods: 1) first period: analysis of oxidative stress and myocardial damage in 18 children. 2) Second period: evaluation of myocardial cell protection by controlled anterograde low oxygen warm reperfusion (ALOWR) before declamping. Twenty-one children were divided in two groups: not receiving (Group 1, 9 patients) and receiving (Group 2, 12 patients) ALOWR. RESULTS: In the first period GSH values increased significantly after onset of mechanical ventilation (MV) in vein, after CPB start in artery and after ACCR in coronary sinus. Moreover TAU turnover in aortic and coronary sinus blood increased significantly after ACCR. In the second period, Group 2 showed a lower oxidative stress after ACCR, while no differences were observed in TAU turnover. CONCLUSIONS: 1) Assessment of TAU and GSH levels can be considered a good method to clinically evaluate myocardial injury during cardiac surgery. 2) MV and CPB can induce oxidative stress before aortic clamping and can decrease the physiologic scavengers. Therefore, to prevent that depletion, the strategy of these techniques must be adapted to the patient and to his cardiac disease. 3) Intramyocardial TAU turnover is not significantly modified by the reperfusion technique. 4) ALOWR can reduce myocardial oxidative stress and can improve heart recovery after the cardioplegic arrest.


Assuntos
Traumatismo por Reperfusão Miocárdica/diagnóstico , Miocárdio/patologia , Estresse Oxidativo , Ponte Cardiopulmonar , Estudos de Casos e Controles , Criança , Glutationa/metabolismo , Humanos , Reperfusão Miocárdica , Miocárdio/metabolismo , Respiração Artificial , Taurina/metabolismo , Fatores de Tempo
4.
Clin Ter ; 153(2): 99-106, 2002.
Artigo em Italiano | MEDLINE | ID: mdl-12078347

RESUMO

INTRODUCTION: The main purpose of this contribution is to set today's situation of technology assessment and point to some organizing and integrative ways with the evolution concern ASL (Local Health Firm). PATIENTS AND METHODS: We outline main critical processes that fix correct management of technological resource thought data available in national and international literature. We single out more common methods to quantify, evaluate, control and manage biomedical technologies. RESULTS: We expound decisional process that lead Viterbo ASL (Local Health Firm) to a progressive controll of tecnological resource and its management after aggregation of the five USL (Local Health Units) that constituted Viterbo ASL and describe procedures assumed. CONCLUSIONS: We underline the importance of full and complete information in business and decisional process. Inside the complexity of italian view, we outline an organizative solution with a low economic impact and with a high technical content.


Assuntos
Equipamentos Médicos Duráveis/provisão & distribuição , Alocação de Recursos para a Atenção à Saúde/organização & administração , Avaliação da Tecnologia Biomédica/organização & administração , Tomada de Decisões Gerenciais , Alocação de Recursos para a Atenção à Saúde/economia , Alocação de Recursos para a Atenção à Saúde/estatística & dados numéricos , Humanos , Itália , Avaliação da Tecnologia Biomédica/economia , Avaliação da Tecnologia Biomédica/estatística & dados numéricos
6.
Regul Pept ; 101(1-3): 123-9, 2001 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-11495687

RESUMO

We have recently shown that the activity of a synthetic peptide corresponding to amino acid residues 116-130 of secreted mouse leptin is contained in a restricted sequence at the amino terminus of the peptide, between residues 116-122 (Ser-Cys-Ser-Leu-Pro-Gln-Thr, OB3). Substitution of the Leu residue at position 4 of OB3 with its D-isomer ([D-Leu-4]-OB3) enhanced the ability of OB3 (1 mg/day, ip, 7 days) to reduce body weight gain, food and water intake, and serum glucose in female C57BL/6J ob/ob mice. In the present study, we have utilized a pair-feeding approach to demonstrate that the antihyperglycemic action of [D-Leu-4]-OB3 is not solely due to its effects on caloric intake. One group of female C57BL/6J ob/ob mice (n=6) was fed ad libitum, and two additional groups (n=6 per group) were allowed 3.0 g food/mouse daily, an amount previously determined to satisfy [D-Leu-4]-OB3-treated mice. At the end of the 7-day test period, vehicle-injected mice fed ad libitum were approximately 10% heavier than their initial body weights, while pair-fed mice injected with vehicle and [D-Leu-4]-OB3-treated mice lost 5% of their initial body weights. After 1 day of treatment, blood glucose was reduced by 20% in pair-fed vehicle-injected mice, and by 40% in mice given [D-Leu-4]-OB3. Food restriction reduced blood glucose throughout the 7-day study, but not to levels seen in wild-type nonobese C57BL/6J mice of the same sex and age. After 2 days of treatment with [D-Leu-4]-OB3, however, blood glucose was reduced to levels comparable to those seen in wild-type nonobese mice. [D-Leu-4]-OB3 also lowered serum insulin levels by 53% when compared to mice fed ad libitum. Neither pair-feeding nor [D-Leu-4]-OB3 treatment had any apparent effect on thermogenesis. These results suggest that [D-Leu-4]-OB3 exerts its effects on serum glucose not only by suppressing caloric intake, but also through a separate effect on glucose metabolism which may involve increased tissue sensitivity to insulin.


Assuntos
Diabetes Mellitus Tipo 2/tratamento farmacológico , Hipoglicemiantes/farmacologia , Leptina/agonistas , Leptina/farmacologia , Fragmentos de Peptídeos/farmacologia , Animais , Glicemia/efeitos dos fármacos , Glicemia/metabolismo , Peso Corporal/efeitos dos fármacos , Diabetes Mellitus Tipo 2/metabolismo , Diabetes Mellitus Tipo 2/fisiopatologia , Ingestão de Líquidos/efeitos dos fármacos , Ingestão de Alimentos/efeitos dos fármacos , Feminino , Hiperglicemia/tratamento farmacológico , Hiperglicemia/metabolismo , Hiperglicemia/fisiopatologia , Hipoglicemiantes/administração & dosagem , Injeções Intraperitoneais , Insulina/sangue , Resistência à Insulina , Leptina/administração & dosagem , Análise por Pareamento , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Obesos , Fragmentos de Peptídeos/administração & dosagem , Termogênese/efeitos dos fármacos , Fatores de Tempo
7.
Endocrinology ; 141(7): 2501-7, 2000 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-10875251

RESUMO

We have previously reported that a synthetic peptide amide corresponding to amino acid residues 116-130 of mouse leptin, LEP-(116-130), reduces body weight gain, food intake, and blood glucose levels in ob/ob and db/db mice. In the present study we show that the activity of LEP-(116-130) resides in a restricted sequence between amino acid residues 116-122. A synthetic peptide corresponding to this sequence (Ser-Cys-Ser-Leu-Pro-Gln-Thr) has been named OB3. Single point D-amino acid substitution was used to study the structure-function relationship of each residue in OB3. D-Amino acid analogs of OB3 were synthesized by the solid phase method, purified to 98+%, and administered (1 mg/day, ip) for 7 days to female C57BL/6J ob/ob mice. The effects of the peptides on body weight gain, food and water intake, glucose homeostasis, and thermoregulation were assessed. In most cases, the efficacy of OB3 on all parameters tested was reduced by substitution of an L-amino acid with its corresponding D-isoform. A statistically significant increase (2.6-fold) in the weight-reducing effect of OB3, however, was observed by inversion of the configuration of the leucine residue at position 4 (Leu-4) of OB3 by substitution with its D-amino acid isoform [D-Leu-4]. Compared with OB3, mice treated with [D-Leu-4]-OB3 consumed 7.9% less food and 16.5% less water. Blood glucose was normalized to levels comparable to those in wild-type control mice within 2 days after initiation of [D-Leu-4]-OB3 treatment. Unlike native leptin, however, neither OB3 nor any of its D-amino acid-substituted analogs had any apparent effect on thermogenesis. Our results indicate that synthetic peptide strategies may be useful in the development of potent and stabile pharmacophores with potential therapeutic significance in the treatment of human obesity and its related metabolic dysfunctions.


Assuntos
Regulação da Temperatura Corporal/efeitos dos fármacos , Metabolismo Energético/efeitos dos fármacos , Glucose/metabolismo , Leptina/agonistas , Substituição de Aminoácidos , Animais , Glicemia/análise , Peso Corporal/efeitos dos fármacos , Ingestão de Líquidos/efeitos dos fármacos , Ingestão de Alimentos/efeitos dos fármacos , Epitopos , Feminino , Homeostase/efeitos dos fármacos , Leptina/síntese química , Leptina/química , Leptina/imunologia , Leptina/farmacologia , Camundongos , Camundongos Endogâmicos C57BL , Fragmentos de Peptídeos/síntese química , Fragmentos de Peptídeos/imunologia , Fragmentos de Peptídeos/farmacologia
8.
J Chem Inf Comput Sci ; 39(6): 1076-80, 1999.
Artigo em Inglês | MEDLINE | ID: mdl-10614025

RESUMO

A back-propagation neural network to predict the carcinogenicity of aromatic nitrogen compounds was developed. The inputs were molecular descriptors of different types: electrostatic, topological, quantum-chemical, physicochemical, etc. For the output the index TD50 as introduced by Gold and colleagues was used, giving a continuous numerical parameter expressing carcinogenicity. From the tens of descriptors calculated, principal component analysis enabled us to restrict the number of parameters to be used for the artificial neural network (ANN). We used 104 molecules for the study. An Rcv2 = 0.69 was obtained. After removal of 12 outliers, a new ANN gave an Rcv2 of 0.82.


Assuntos
Carcinógenos/toxicidade , Redes Neurais de Computação , Testes de Carcinogenicidade , Carcinógenos/química , Modelos Químicos , Nitrogênio/química , Relação Estrutura-Atividade
9.
Regul Pept ; 84(1-3): 21-8, 1999 Oct 22.
Artigo em Inglês | MEDLINE | ID: mdl-10535404

RESUMO

We have recently reported that a synthetic peptide corresponding to amino acid residues 81-95, a receptor-binding region of the human FSH-beta-subunit, and a subdomain within this region, hFSH-beta-(90-95) (DSTDCT), prolonged vaginal estrus when administered intraperitoneally (ip) to normally cycling Swiss Webster mice. These results were similar to those we reported for a synthetic peptide corresponding to hFSH-beta-(34-37) [TRDL, a subdomain within receptor-binding region hFSH-beta-(33-53)] in the same model system. TRDL also accelerated the onset of puberty in immature mice. We now report the effects of hFSH-beta-(90-95) in prepubertal female mice. In two separate experiments, a single ip injection of 200 microg/g body weight (BW) hFSH-beta-(90-95) in phosphate buffered saline (PBS, vehicle) administered to mice on day 28 delayed first vaginal estrus by 3 days in 50% (4/8) and 62.5% (6/8) when compared to mice given vehicle alone on day 28. Vaginal opening was also delayed in mice receiving hFSH-beta-(90-95) when compared to mice injected with vehicle alone. Serum estradiol levels of vehicle-injected control mice in first vaginal estrus were three-fold higher than in mice treated with hFSH-beta-(90-95), whose vaginal smears showed no evidence of first estrus. No significant differences in ovarian or uterine weights, or serum progesterone levels, were observed between vehicle-injected control mice achieving first vaginal estrus and mice receiving hFSH-beta-(90-95) in whom first estrus was delayed. The contrasting effects on the onset of puberty of hFSH-beta-(90-95) (delay) and hFSH-beta-(34-37) (acceleration) may reflect synthetic peptide binding to different domains of the FSH receptor, resulting in variable post-binding effects. These results are consistent with our earlier study suggesting that FSH-beta-subunit-related synthetic peptides can induce significant in vivo effects on the onset of puberty in female mice.


Assuntos
Hormônio Foliculoestimulante/química , Fragmentos de Peptídeos/farmacologia , Maturidade Sexual/efeitos dos fármacos , Animais , Estradiol/sangue , Estro/efeitos dos fármacos , Feminino , Subunidade beta do Hormônio Folículoestimulante , Humanos , Camundongos , Tamanho do Órgão/efeitos dos fármacos , Ovário/efeitos dos fármacos , Progesterona/sangue , Útero/efeitos dos fármacos
10.
Diabetes ; 48(11): 2204-9, 1999 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-10535455

RESUMO

We recently reported that intraperitoneal administration of leptin-related synthetic peptide 116-130 [LEP-(116-130)] resulted in reduced food intake and significant weight loss in homozygous female C57BL/6J ob/ob mice. In this study, we used two in vitro bioassays to show that the interaction of LEP-(116-130) with the long form of the leptin receptor (OB-Rb), the receptor isoform that is predominantly expressed in the hypothalamus, is not required for the observed in vivo effects of the peptide on energy balance. LEP-(116-130) was unable to compete the binding of alkaline phosphatase-leptin fusion protein to OB-R. Moreover, LEP-(116-130) was unable to activate signal transduction by OB-Rb in vitro. In homozygous female C57BLKS/J-m db/db mice that do not express OB-Rb, intraperitoneal administration of LEP-(116-130) reduced body weight gain and blood glucose levels but not food intake, which further supports a mechanism of action that does not require peptide interaction with OB-Rb.


Assuntos
Glicemia/metabolismo , Proteínas de Transporte/fisiologia , Comportamento Alimentar/efeitos dos fármacos , Leptina/farmacologia , Fragmentos de Peptídeos/farmacologia , Receptores de Superfície Celular , Aumento de Peso/efeitos dos fármacos , Animais , Glicemia/efeitos dos fármacos , Regulação da Temperatura Corporal/efeitos dos fármacos , Células COS , Proteínas de Transporte/efeitos dos fármacos , Proteínas de Transporte/genética , Linhagem Celular , Comportamento Alimentar/fisiologia , Feminino , Homozigoto , Hipotálamo/fisiologia , Ligantes , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Obesos , Receptores para Leptina , Proteínas Recombinantes/efeitos dos fármacos , Proteínas Recombinantes/metabolismo , Transfecção , Aumento de Peso/fisiologia
11.
Regul Pept ; 81(1-3): 67-71, 1999 May 31.
Artigo em Inglês | MEDLINE | ID: mdl-10395410

RESUMO

We have previously reported that synthetic peptide amides corresponding to subdomains of the human FSH 3-subunit, hFSH-beta-(33--53) and hFSH-beta-(81--95), interact with the external domain of the FSH receptor in two in vitro model systems. Consistent with these in vitro observations, we found that intraperitoneal (i.p.) administration of each of these peptides prolonged vaginal estrus in normally cycling mice in vivo. Both hFSH-beta-(33--53) and hFSH-beta-(81--95) contain cysteine (Cys) residues with free sulfhydryl groups of potential significance in receptor interactions. To assess the possible involvement of these groups in the in vivo effects of hFSH-beta-(33--53) and hFSH-beta-(81--95), synthetic peptide analogs were prepared in which all Cys residues were replaced with serine (Ser). In the present study, we demonstrate that the in vivo effect of hFSH-beta-(33--53) on the mouse estrous cycle, extension of vaginal estrus, was not changed by substitution of Cys-51 with Ser. In contrast, mice receiving the Ser-substituted analog of hFSH-beta-(81--95) had normal estrus stages, but were arrested in diestrus. hFSH-beta-(33--53)-(81--95), a linear peptide encompassing both domains, also prolonged vaginal estrus. The Ser-substituted analog of this peptide, however, prolonged vaginal estrus in some of the mice tested and induced cycle arrest at diestrus in others. hFSH-beta-(90--95), the active subdomain at the C-terminus of hFSH-beta-(81--95), extended vaginal estrus, but diestrus stages were of normal duration. Its Ser-substituted analog, however, prolonged the estrus stage of the majority of mice treated, but induced diestrus arrest in some. The differing responses to these peptides are presumably due to interactions of the synthetic peptides with different regions of the FSH receptor. This further suggests that one consequence of ligand interaction with multiple receptor binding domains may be variable effects on ovarian function, and that Cys to Ser analogs may have value in the design of a novel class of synthetic peptides capable of fertility regulation and control.


Assuntos
Estro/fisiologia , Hormônio Foliculoestimulante Humano , Subunidade beta do Hormônio Folículoestimulante/análogos & derivados , Hormônio Foliculoestimulante/metabolismo , Fragmentos de Peptídeos/metabolismo , Sequência de Aminoácidos , Substituição de Aminoácidos , Animais , Sítios de Ligação , Cisteína/metabolismo , Estro/efeitos dos fármacos , Feminino , Hormônio Foliculoestimulante/análogos & derivados , Hormônio Foliculoestimulante/farmacologia , Humanos , Camundongos , Dados de Sequência Molecular , Fragmentos de Peptídeos/farmacologia , Serina/metabolismo
12.
Chemosphere ; 38(12): 2753-65, 1999 May.
Artigo em Inglês | MEDLINE | ID: mdl-10214713

RESUMO

We used the duplicate portion method to measure the daily dietary intake of total and congener-specific polychlorinated biphenyls (PCB) and to assess their potential toxicity in a group of 20 subjects consuming a typical Italian diet. The mean +/- SD intake of total PCB, measured by GC-MS, was 3.72 +/- 1.51 micrograms/person/day, comparable to values reported in similar studies world-wide, with individual intakes varying within one order of magnitude, from 0.97 to 10.59 micrograms/person/day. The di-ortho congeners 153, 18 and 138 were the PCB found in the highest concentrations (respectively 13.8%, 11.4% and 10.9% of the total) while the non-ortho coplanar congeners (77, 126 and 169) amounted to 0.5% of the total. The corresponding levels of toxicity (TCDD-like TEQ values ascribable to PCB) ranged from 4.6 up to 119 pg/person/day of TCDD-equivalents in 18 subjects, i.e. presumed no-risk levels, but with peaks of 2109 and 4553 pg/person/day in two subjects with significant intakes of the congener 126. Principal components analysis and redundancy analysis showed dairy products, meat and fish were the principal sources of PCB, and vegetables those with the highest toxicity index in the Italian diet.


Assuntos
Dieta , Poluentes Ambientais/análise , Poluentes Ambientais/toxicidade , Contaminação de Alimentos , Bifenilos Policlorados/análise , Bifenilos Policlorados/toxicidade , Adulto , Poluentes Ambientais/metabolismo , Feminino , Cromatografia Gasosa-Espectrometria de Massas , Humanos , Itália , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Bifenilos Policlorados/metabolismo , Dibenzodioxinas Policloradas/toxicidade
13.
Regul Pept ; 85(2-3): 93-100, 1999 Dec 23.
Artigo em Inglês | MEDLINE | ID: mdl-10651062

RESUMO

We have recently reported that intraperitoneal (i.p.) administration of synthetic peptide amides corresponding to amino acids 106-140 of mouse leptin significantly reduced food intake and body weight gain in female C57BL/6J ob/ob mice. These results suggested that leptin activity was localized in domains toward its C-terminus between residues 106-140. In the present study, 14 overlapping peptides encompassing the complete sequence of secreted mouse leptin were synthesized, and their effects on body weight and food intake in female C57BL/6 J ob/ob mice were assessed. When given as seven daily 1-mg i.p. injections, only peptides corresponding to amino acids 106-120, 116-130 and 126-140 caused significant reductions in body weight and food intake. These results confirmed our earlier study and suggest that in contrast to the domain encompassed by amino acids 106-140, the N-terminal of mouse leptin between amino acids 21-105 may not contain functional epitopes that can be utilized as lead compounds in the development of peripherally administered bioactive peptide analogs or nonpeptide mimetics of leptin, which may have potential usefulness in treatment of the energy imbalance associated with obesity.


Assuntos
Leptina/imunologia , Sequência de Aminoácidos , Animais , Peso Corporal/efeitos dos fármacos , Relação Dose-Resposta a Droga , Ingestão de Alimentos/efeitos dos fármacos , Mapeamento de Epitopos , Feminino , Injeções Intraperitoneais , Leptina/genética , Leptina/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Obesos , Dados de Sequência Molecular , Obesidade/genética , Obesidade/fisiopatologia , Fragmentos de Peptídeos/administração & dosagem , Fragmentos de Peptídeos/genética , Estrutura Terciária de Proteína
14.
J Chromatogr A ; 822(1): 91-9, 1998 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-9810713

RESUMO

It is essential to know whether drinking water contains any pesticides up to concentrations close to the European Union limit of 0.1 microgram/l, in order to protect the population. Mass spectrometry (MS) using a suitable internal standard (I.S.) should improve the quantitative analysis of pesticides, the I.S. circumventing loss of compounds during the analytical procedure and correcting the analytical variability. In this study we verified this assumption in GC-MS, synthesising specific internal standards for four organophosphorus pesticides with poor stability, comparing the performances with and without the I.S.


Assuntos
Inseticidas/análise , Compostos Organofosforados , Poluentes Químicos da Água/análise , Abastecimento de Água/análise , Deutério , Cromatografia Gasosa-Espectrometria de Massas , Padrões de Referência
15.
Food Chem Toxicol ; 36(11): 1015-29, 1998 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-9771564

RESUMO

No carcinogenic activity was observed when snuff was inserted into the cheek pouch of the hamster or spread over the oral mucosa. This negative result was obtained in a number of experiments whether snuff was applied once only and left in place for several months or inserted repeatedly for up to 2 years. In the rat, a few tumours were observed when snuff was inserted into the artificial lip canal. The insertion appeared to cause a considerable reaction in the surrounding tissue so it is plausible to assume that trauma plays an important role in the development of these tumours. An extract of snuff applied to the oral mucosa of the rat did not produce any tumours, but an extract enriched by the addition of 10 times the naturally-occurring amounts of NNN and NNK produced a few benign tumours at the site of application. A higher incidence of tumours was produced when an equivalent amount of an aqueous solution of these two nitrosamines was applied directly to the oral mucosa, suggesting, according to the authors, that snuff inhibits the carcinogenic activity of TSNAs. Initiation/promotion studies were carried out on snuff in the rat in order to explore further its carcinogenic potential. The results were consistent with the conclusion that snuff does not possess any promotional activity. No increase in tumour incidence was observed in mice when snuff was given in the diet at concentrations of 25% gradually decreasing to 5% in a 14 month study. A negative result was also obtained in the rat given snuff at a concentration of 5% for 18 months. In hamsters given snuff at a concentration of 20% for 2 years, forestomach tumours occurred. A comparable incidence of this type of tumour occurred in animals given 20% cellulose. The result of this study does not provide valid evidence of carcinogenicity. HSV and snuff applied orally in the hamster produced a high incidence of squamous cell carcinomas. The sustained high level of squamous cell hyperplasia generated by the experimental design could account for the development of these tumours. Despite the defects in some of the earlier studies, the sum total of this experimental work suggests that snuff is not carcinogenic to the oral mucosa of the hamster or the rat. It is also unlikely to cause tumours in other tissues in these species. These results give some degree of reassurance that snuff is not likely to be carcinogenic to the human oral mucosa. The interaction of snuff and HSV viruses is, at the moment, questionable and requires further investigation.


Assuntos
Carcinógenos/toxicidade , Carcinoma de Células Escamosas/induzido quimicamente , Neoplasias Bucais/induzido quimicamente , Plantas Tóxicas , Tabaco sem Fumaça/toxicidade , Animais , Testes de Carcinogenicidade , Cricetinae , Dieta , Camundongos , Mucosa Bucal/efeitos dos fármacos , Mucosa Bucal/patologia , Extratos Vegetais/toxicidade , Ratos , Especificidade da Espécie
17.
Eur J Obstet Gynecol Reprod Biol ; 79(1): 39-41, 1998 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-9643401

RESUMO

OBJECTIVE: We surveyed the attitudes of Italian obstetricians toward the application of HIV infection control guidelines during labour and delivery proposed by the Italian National Committee for HIV Infection. STUDY DESIGN: We identified 66 obstetric centres affiliated to the AOGOI (Association of Italian Gynecologists and Obstetricians). A postal questionnaire was sent to 752 physicians in charge in the centres. RESULTS: A total of 419 clinicians (55.7%) completed and returned the form to the coordinating centre. Obstetricians were directly asked about the need for routine adoption of the Italian guidelines for delivery of women with positive or unknown HIV status (indicating the routine use during delivery of protective glasses, impermeable garments, mask and sterile latex gloves, the washing of hands with detergent solution after using gloves and collection of needles and sharp instruments in suitable containers). A total of 319 (76.1%) clinicians agreed that all these procedures should be adopted. In clinical practice, however, obstetricians declared that the use of latex gloves and collecting needles in suitable containers were always adopted, 'washing hands after using gloves' less frequently, and other procedures such as protective impermeable garments, glasses and mask were infrequently applied.


Assuntos
Parto Obstétrico , Fidelidade a Diretrizes , Infecções por HIV/transmissão , Doenças Profissionais/prevenção & controle , Complicações Infecciosas na Gravidez , Adulto , Idoso , Feminino , Humanos , Itália/epidemiologia , Pessoa de Meia-Idade , Gravidez , Prevalência , Inquéritos e Questionários
18.
Biol Reprod ; 58(3): 821-5, 1998 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-9510972

RESUMO

We have previously reported that a synthetic peptide corresponding to amino acid residues 81-95 of the human (h) FSH-beta subunit inhibited binding of [125I]hFSH to bovine calf testis membranes and stimulated estradiol biosynthesis in primary cultures of rat Sertoli cells. We have now obtained several lines of evidence demonstrating in vivo effects of hFSH-beta-(81-95) on the mouse estrous cycle. 1) A single i.p. injection of 200 micrograms/g BW hFSH-beta-(81-95) significantly (p < 0.001) prolonged vaginal estrus in comparison to that in vehicle-injected control mice. 2) Vaginal smears taken at estrus from mice given hFSH-beta-(81-95) were characterized by the complete absence of epithelial casts, a hallmark of spontaneous ovulation in mice. 3) Mice receiving hFSH-beta-(81-95) had significantly (p < 0.001) lower serum estradiol at proestrus and serum progesterone at diestrus than vehicle-injected control mice. 4) The proestrous effects of estrogen on uterine ballooning and weight gain, clearly evident in vehicle-injected control mice, were not observed in mice treated with hFSH-beta-(81-95). A synthetic peptide corresponding to the carboxy-terminal region of hFSH-beta-(81-95), hFSH-beta-(90-95), inhibited binding of [125I]hFSH to bovine calf testis membranes, antagonized FSH-stimulated estradiol biosynthesis by primary cultures of rat Sertoli cells, and prolonged vaginal estrus in normally cycling mice. A synthetic peptide corresponding to the amino-terminal domain, hFSH-beta-(81-86), was inactive in vitro and had no effect on the mouse estrous cycle. The results of the present study provide additional evidence for in vivo effects of FSH-related synthetic peptides.


Assuntos
Estro/efeitos dos fármacos , Hormônio Foliculoestimulante Humano , Subunidade beta do Hormônio Folículoestimulante , Hormônio Foliculoestimulante/farmacologia , Fragmentos de Peptídeos/farmacologia , Animais , Bovinos , Células Cultivadas , Estradiol/sangue , Estro/fisiologia , Feminino , Hormônio Foliculoestimulante/síntese química , Hormônio Foliculoestimulante/metabolismo , Humanos , Técnicas In Vitro , Masculino , Camundongos , Tamanho do Órgão/efeitos dos fármacos , Ovário/anatomia & histologia , Ovário/efeitos dos fármacos , Fragmentos de Peptídeos/síntese química , Progesterona/sangue , Ratos , Células de Sertoli/efeitos dos fármacos , Células de Sertoli/metabolismo , Esteroides/biossíntese , Útero/anatomia & histologia , Útero/efeitos dos fármacos , Vagina/anatomia & histologia , Vagina/efeitos dos fármacos , Vagina/fisiologia
19.
Endocrinology ; 138(10): 4215-9, 1997 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-9322932

RESUMO

We have previously reported that a synthetic peptide amide corresponding to residues 34-37 (TRDL, threonine, arginine-aspartic acid-leucine) of the beta-subunit of human FSH induced prolonged vaginal estrus in normally cycling female mice (see Ref. 15). These results represented the first demonstration of an in vivo effect of a gonadotropin-related synthetic peptide on reproductive processes. We have extended these studies to examine possible effects of TRDL on the onset of puberty in female mice. In two replicated experiments, vehicle-injected control mice attained first vaginal estrus by day 39. An ip injection of 200 ug TRDL/g BW to 28-day-old prepubertal female mice, however, accelerated the onset of first vaginal estrus by 7 days in 11 of 12 (11/12) (Exp 1) and 7/9 (Exp 2) mice. Serum estradiol levels were significantly (P = 0.017) elevated in TRDL-treated mice, whereas progesterone was unchanged. Uteri of TRDL-treated mice were significantly (P = 0.003) heavier than uteri of vehicle-injected control animals of the same age and body weight. Intraluminal fluid accumulation (ballooning) at proestrus was absent in 20/21 TRDL-treated females, as were oviductal ova and ovarian corpora lutea. These phenomena are characteristic of the first estrous cycles of female mice isolated from males. To obtain further evidence for in vivo effects of TRDL, we assessed the ability of TRDL to accelerate the onset of puberty in male mice. When given as five consecutive daily ip injections of 200 ug/g BW to 28-day-old prepubertal male mice, TRDL significantly increased testis weight, when compared with vehicle-injected control mice of the same age and BW (171.3 +/- 3.8 mg vs. 151.6 +/- 4.3 mg, P = 0.001) and induced a 6.5-fold increase in serum testosterone levels. These studies confirm the previously reported in vivo activity of a synthetic peptide corresponding to human FSH-beta subunit 34-37 (TRDL) in adult female mice and extend its effects to the acceleration of the onset of puberty in immature male and female mice.


Assuntos
Aminoácidos/química , Hormônio Foliculoestimulante/química , Hormônios/farmacologia , Fragmentos de Peptídeos/farmacologia , Maturidade Sexual/efeitos dos fármacos , Animais , Peso Corporal/efeitos dos fármacos , Peso Corporal/fisiologia , Estradiol/sangue , Estro/efeitos dos fármacos , Estro/fisiologia , Feminino , Fertilidade/efeitos dos fármacos , Fertilidade/fisiologia , Subunidade beta do Hormônio Folículoestimulante , Hormônios/química , Humanos , Masculino , Camundongos , Tamanho do Órgão , Ovário/anatomia & histologia , Ovário/efeitos dos fármacos , Fragmentos de Peptídeos/química , Progesterona/sangue , Radioimunoensaio , Maturidade Sexual/fisiologia , Testículo/anatomia & histologia , Testículo/efeitos dos fármacos , Testosterona/sangue , Fatores de Tempo , Útero/anatomia & histologia , Útero/efeitos dos fármacos
20.
Am J Ind Med ; 32(4): 403-7, 1997 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-9258394

RESUMO

Clusters of spontaneous abortion among video display terminal (VDT) users in North America and Canada in the late 1970s aroused suspicion about the potential risk of an association between VDT. exposure and pregnancy outcome. This case-control study considered the association between VDT use and the risk of miscarriage. Cases were 508 women admitted for spontaneous abortion to the Clinica Luigi Mangiagalli and a network of obstetric departments in the Milan area. Controls were 1,148 women who gave birth at term to healthy infants on randomly selected days at the same hospitals where cases were identified. No association emerged between VDT exposure and spontaneous abortion, the estimated odds ratio being 1.0 (95% CI: 0.8-1.2). This evidence agrees with studies conducted in different countries by various authors.


Assuntos
Aborto Espontâneo/etiologia , Terminais de Computador , Fenômenos Eletromagnéticos , Exposição Ocupacional , Aborto Espontâneo/epidemiologia , Adolescente , Adulto , Estudos de Casos e Controles , Intervalos de Confiança , Feminino , Humanos , Itália/epidemiologia , Modelos Logísticos , Razão de Chances , Gravidez , Resultado da Gravidez
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...