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2.
J AOAC Int ; 90(4): 1050-9, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-17760343

RESUMO

Fumonisins are toxic and carcinogenic compounds produced by fungi that can be readily found in maize. The establishment of maximum limits for fumonisins requires the development of scientifically based sampling plans to detect fumonisin in maize. As part of an International Atomic Energy Agency effort to assist developing countries to control mycotoxin contamination, a study was conducted to design sampling plans to detect fumonisin in maize produced and marketed in Nigeria. Eighty-six maize lots were sampled according to an experimental protocol in which an average of 17 test samples, 100 g each, were taken from each lot and analyzed for fumonisin B1 by using liquid chromatography. The total variability associated with the fumonisin test procedure was measured for each lot. Regression equations were developed to predict the total variance as a function of fumonisin concentration. The observed fumonisin distribution among the replicated-sample test results was compared with several theoretical distributions, and the negative binomial distribution was selected to model the fumonisin distribution among test results. A computer model was developed by using the variance and distribution information to predict the performance of sampling plan designs to detect fumonisin in maize shipments. The performance of several sampling plan designs was evaluated to demonstrate how to manipulate sample size and accept/reject limits to reduce misclassification of maize lots.


Assuntos
Análise de Alimentos/métodos , Fumonisinas/análise , Zea mays/química , Zea mays/metabolismo , Cromatografia Líquida de Alta Pressão , Cromatografia Líquida/métodos , Relação Dose-Resposta a Droga , Contaminação de Alimentos , Modelos Estatísticos , Modelos Teóricos , Nigéria , Plantas/metabolismo , Análise de Regressão , Reprodutibilidade dos Testes , Projetos de Pesquisa , Tamanho da Amostra
4.
Coll Antropol ; 26(1): 55-60, 2002 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-12137323

RESUMO

Prospective investigation has been undertaken with the aim to study the frequency, location and age and sex distribution of various histological types of benign gastric epithelial polyps. Histological type--adenomatous, hyperplastic and fundic gland polyps--was diagnosed on the basis of at least three histological samples taken from the polyp. Biopsy samples were also taken from the antrum and the body of the stomach so that gastritis could be graded and classified, and the presence of H. pylori could be determined by histology. All 6,700 patients, who had undergone upper gastrointestinal endoscopy in a one-year period, participated in this study. Among them 42 benign gastric epithelial polyp were found in 31 patients: adenomatous gastric polyps in 7 patients, hyperplastic gastric polyp in 21 and fundic gland polyp in 3 patients. All patients with hyperplastic polyps had chronic active superficial gastritis, whereas most of the patients with adenomatous polyps had a chronic atrophic gastritis with high prevalence of intestinal metaplasia. Among 21 patients with hyperplastic gastric polyps, 16 (76%) patients were positive for H. pylori infection in contrast to only 2 patients (29%) with adenomatous gastric polyps and 1 patient (33%) with fundic gland polyp. Presented data indicates that hyperplastic gastric polyps are the most common and they are associated with the presence of chronic active superficial gastritis and concomitant H. pylori infection. Adenomatous polyps are rarer and they tend to be associated with chronic atrophic gastritis and intestinal metaplasia. Fundic gland polyp is the rarest type of gastric polyps.


Assuntos
Pólipos/patologia , Neoplasias Gástricas/patologia , Pólipos Adenomatosos/patologia , Fatores Etários , Idoso , Feminino , Fundo Gástrico , Gastrite/complicações , Infecções por Helicobacter/complicações , Helicobacter pylori , Humanos , Hiperplasia , Masculino , Pessoa de Meia-Idade , Pólipos/complicações , Pólipos/diagnóstico , Fatores Sexuais , Neoplasias Gástricas/complicações , Neoplasias Gástricas/diagnóstico
5.
Endocrine ; 16(2): 69-71, 2001 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-11887936

RESUMO

The occurrence of inflammatory bowel disease in patients with glycogen storage disease lb is rare (GSD-lb). We present the case of a young woman with the diagnosis of GSD-lb Crohn-like colitis developed at age 22. Clinical evaluation revealed severe malnutrition, secondary amenorrhea, leukopenia, neutropenia, dysfunctions of phagocytosis, and subtotal stenosis of the ascending colon. Right hemicolectomy was performed and pathohistologic analysis of the resected bowel showed chronic bowel inflammation consistent with Crohn disease. Clinical status of the patient markedly improved after surgery.


Assuntos
Colite/complicações , Doença de Crohn/complicações , Doença de Depósito de Glicogênio Tipo I/complicações , Adulto , Colectomia , Colite/diagnóstico por imagem , Colite/patologia , Colite/cirurgia , Doença de Crohn/diagnóstico por imagem , Doença de Crohn/patologia , Doença de Crohn/cirurgia , Feminino , Humanos , Radiografia
6.
Acta Med Croatica ; 55(4-5): 157-60, 2001.
Artigo em Inglês | MEDLINE | ID: mdl-12398018

RESUMO

Histopathologic and clinical data strongly suggest a causal relation between Helicobacter pylori infection and gastritis, peptic ulcer disease, or both. However, little has been written about the potential association between H. pylori infection and Brunner's gland adenoma. Therefore, we carried out a prospective study to determine the presence of H. pylori infection among patients with Brunner's gland adenoma. From November 1996 till October 1999, 19100 patients who had undergone upper gastrointestinal endoscopy at two clinical centers in Zagreb, Croatia, were candidates for participation in the study. Brunner's gland adenoma was diagnosed on the basis of histologic samples taken from the polyp (four patients) or after the entire polyp was made available upon endoscopic removal (three patients). When all endoscopic examinations had been performed, biopsy samples were taken from the antrum and body of the stomach, so that gastritis could be classified and H. pylori determined by histology. Biopsy samples were also taken from the duodenal bulb to verify duodenitis. Two other samples were taken from the antrum for rapid urease test. The patients were considered positive for H. pylori when both histology and rapid urease test were positive. Brunner's gland adenoma was diagnosed in seven patients (five women and two men; median age, 49 yrs). Five (71%) patients with diagnosed Brunner's gland adenoma had concurrent H. pylori infection. Duodenitis associated with gastric metaplasia was observed in six patients. Complete eradication of H. pylori was achieved in only two patients. Symptoms disappeared or markedly diminished in all patients with significant improvement during therapy or immediately upon endoscopic removal of the polyp. Although limited by a very small number of patients, our results suggest that concurrent H. pylori infection is very common in patients with Brunner's gland adenoma. However, the role of H. pylori infection in the pathogenesis and development of Brunner's gland hyperplasia remains unclear.


Assuntos
Adenoma/complicações , Glândulas Duodenais , Neoplasias Duodenais/complicações , Infecções por Helicobacter/complicações , Helicobacter pylori , Adulto , Feminino , Infecções por Helicobacter/tratamento farmacológico , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos
7.
Hepatogastroenterology ; 47(35): 1360-3, 2000.
Artigo em Inglês | MEDLINE | ID: mdl-11100352

RESUMO

BACKGROUND/AIMS: Spontaneous bacterial peritonitis is one of the most common complications attending the onset of ascites in patients with liver cirrhosis. The aim of this study was to demonstrate whether it is possible, on the basis of ascitic fluid polymorphonuclear cell count in patients with liver cirrhosis and spontaneous bacterial peritonitis, to determine the optimal duration of cefotaxime therapy, as the most frequently applied empirical therapy, and possibly anticipate the disease recurrence. METHODOLOGY: In 16 patients with alcoholic liver cirrhosis and confirmed diagnosis of spontaneous bacterial peritonitis, cefotaxime therapy was administered 2g t.i.d. during 5 days. Before the therapy, at 48 hours, 5 days and 15-20 days after the cefotaxime therapy was started, in all patients with spontaneous bacterial peritonitis diagnostic abdominal paracentesis was performed, each time determining the ascitic fluid polymorphonuclear cell count together with microbiological analysis. RESULTS: In the course of the "primary" spontaneous bacterial peritonitis attack, 3 patients died (18.8%). In 4 patients the recurrence of spontaneous bacterial peritonitis was observed within 15-20 days after therapy was discontinued. Two patients died during the therapy of spontaneous bacterial peritonitis recurrence. After 48 hours of therapy, 11 patients with the "primary" spontaneous bacterial peritonitis attack were without any symptoms (68.8%). Out of these 11, 10 patients (62.5%) had the ascitic fluid polymorphonuclear cell count lower than 250/mm3. After 5 days of therapy, 12 patients (75%) were free of symptoms, and the number of ascitic fluid polymorphonuclear cell count < 250/mm3 was still found in 10 (62.5%) patients. No association between the presence of symptoms 48 hours after the therapy and the recurrence of spontaneous bacterial peritonitis was established. A significant association was found between the ascitic fluid polymorphonuclear cell count determined 48 hours after the therapy and the recurrence of spontaneous bacterial peritonitis. A recurrence occurred in only 1 patient with the number of ascitic fluid polymorphonuclear cell count < 250/mm3, 48 hours after the therapy was started. A recurrence of spontaneous bacterial peritonitis occurred in all the patients who had an ascitic fluid PMN cell count > or = 250/mm3, 48 hours after the therapy was started. CONCLUSIONS: By monitoring the ascitic fluid PMN cell count it seems to be possible to determine the efficacy and optimal duration of cefotaxime therapy in patients with spontaneous bacterial peritonitis when it is of most importance that the number of ascitic fluid PMN cell count should decrease below 250/mm3 during the therapy.


Assuntos
Líquido Ascítico/citologia , Infecções Bacterianas/tratamento farmacológico , Infecções Bacterianas/patologia , Cefotaxima/uso terapêutico , Cefalosporinas/uso terapêutico , Cirrose Hepática Alcoólica/complicações , Neutrófilos/citologia , Peritonite/tratamento farmacológico , Peritonite/patologia , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Recidiva
8.
Coll Antropol ; 24(2): 381-90, 2000 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-11216406

RESUMO

Liver resection is the only potentially curative method for patients with colorectal cancer metastases and 5-year survival rates are 20%-40%. Simultaneous resection of colorectal cancer and synchronous liver metastases has been recommended if minor hepatectomy is indicated. The purpose of this paper is to analyze the treatment of hepatic colorectal secondaries and to assess the safety of simultaneous and delayed liver resections and relations of morbidity to the extensiveness of hepatectomy and perioperative factors. Analyzed were 21 patients with liver metastases from colorectal cancer operated between 1997 and 1999 in the Clinical Hospital "Sestre milosrdnice". Operating time for simultaneous colorectal and liver resections was not significantly longer compared to liver resections alone. No significant difference in complication rate was found after simultaneous procedures and liver resection alone (38% vs. 31%). Complication rate after major liver resections was not significantly greater than after minor resections (38% vs. 31%). No statistically significant differences were found in operation time and blood replacement between patients who developed postoperative complications and those who did not. In conclusion, simultaneous resections of primary colorectal cancer and liver metastases may be considered safe. Morbidity rates are not significantly different from those after liver resections alone, nor depend significantly upon the extensiveness of liver resection, providing that the operation time and blood loss are within the range observed in this study.


Assuntos
Neoplasias Colorretais/patologia , Neoplasias Colorretais/cirurgia , Hepatectomia/métodos , Neoplasias Hepáticas/patologia , Neoplasias Hepáticas/cirurgia , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Morbidade , Complicações Pós-Operatórias , Estudos Retrospectivos , Análise de Sobrevida , Fatores de Tempo , Resultado do Tratamento
9.
Drug Dev Ind Pharm ; 25(11): 1149-56, 1999 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-10596352

RESUMO

Microcrystalline cellulose (MCC), sodium carboxymethylcellulose (NaCMC), hydroxypropylmethylcellulose (HPMC), hydroxyethylcellulose (HEC), hydroxypropylcellulose (HPC), and ethylcellulose (EC) were used for the production of time-controlled acetaminophen delivery systems using a spray-drying technique. The influence of factors such as polymer concentration, inlet temperature, and drug/polymer ratio were investigated. The product yields were a function of the type and concentration of the polymer, with the highest values being reached from feeds containing 1% MCC and EC. Parameters of 1% polymer concentration and an inlet temperature of 140 degrees C gave rise to optimal processing conditions. Using these parameters, the influence of some adjuncts, such as polyethylene glycol 6000 (PEG 6000), dibutyl sebacate (DBS), polyvinylpyrrolidone (PVP), and carboxylic acids such as citric acid (CA), phthalic acid (PA), succinic acid (SA), tartaric acid (TA), and oxalic acid (OA), on the spray-drying process was evaluated. Of the additives tested, PVP (with MCC), DBS (with EC), and PEG 6000 (with NaCMC) induced yield decreases from 70% to 49%, 66% to 39%, and 37% to 17%, respectively. As for carboxylic acids (with NaCMC), similar or better performances of 43%, 45%, 47%, and 49% were obtained with SA, OA, PA, and TA, respectively. Dissolution studies in pH 1 dilute HCl and pH 6.8 phosphate buffer dissolution media showed that formulations consisting of 1% polymer with a drug/polymer ratio of 1/1 exhibited the slowest drug release, with the spheroids coated with NaCMC and HEC showing the longest T50% values (with 45 and 53 min at pH 1 and 49 and 55 min at pH 6.8, respectively). Slightly better sustained drug release in pH 6.8 dissolution medium was reached, showing the following trend: HEC > NaCMC > MCC > EC > HPMC. Concerning the additives, the trends in dissolution T50% of drug revealed TA > SA > CA > OA > PVP > PA > DBS in acidic pH 1 dissolution medium and PVP > OA > TA > SA > PA > CA > DBS in phosphate buffer at pH 6.8.


Assuntos
Acetaminofen/administração & dosagem , Analgésicos não Narcóticos/administração & dosagem , Celulose/análogos & derivados , Celulose/química , Acetaminofen/farmacocinética , Analgésicos não Narcóticos/farmacocinética , Composição de Medicamentos , Sistemas de Liberação de Medicamentos , Excipientes , Concentração de Íons de Hidrogênio , Microscopia Eletrônica de Varredura , Solubilidade
10.
Eur J Gastroenterol Hepatol ; 11(7): 727-30, 1999 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-10445791

RESUMO

OBJECTIVE: Histopathological and clinical data strongly suggest that Helicobacter pylori is the cause of chronic gastritis and peptic ulceration. However, little has been written about the potential causal relation of H. pylori infection to hyperplastic and adenomatous gastric polyps. We therefore carried out a prospective study to determine the effect of eradicating H. pylori infection on the course of hyperplastic and adenomatous gastric polyps. METHODS: From November 1996 to December 1997, 6700 patients who had undergone upper gastrointestinal endoscopy at the two centres in Zagreb, Croatia, were candidates for participation in the study. Hyperplastic and adenomatous polyps were diagnosed on a basis of at least three histological samples taken from the polyp. In seven patients endoscopy had to be repeated because forceps biopsy sampling either provided inadequate tissue for correct histological diagnosis, or accurate characterization of gastric polyp histology was not possible. Upon completion of all endoscopic examinations before and after treatment, biopsy samples were taken from the antrum (two) and the body of the stomach (two) so that gastritis could be graded and classified, and the presence of H. pylori sought by histology. Two other samples were taken from the antrum for a rapid urease test. Follow-up examinations were performed by using endoscopy. Control endoscopy was performed at least 4 weeks after the treatment of H. pylori infection had been completed, and then every 3-4 months. The follow-up ranged from 4 to 17 months, with a median of 14 months. The treatment of H. pylori infection consisted of a 1-week course of either omeprazole (20 mg twice daily) or pantoprazole 40 mg twice daily), and a 1-week course of amoxicillin 2g twice daily) and metronidazole (400 mg three times daily), and clarithromycin (500 mg twice daily). Eradication of H. pylori infection was assessed by repeated histology and rapid urease test. RESULTS: Twenty-one patients (nine women, 12 men; median age 52 years) with histologically proven hyperplastic gastric polyps, and seven patients (two women, five men; median age, 67 years) with adenomatous gastric polyps were included in the study. Among 21 patients with hyperplastic gastric polyps, 16 patients (76%) were positive for H. pylori infection. Only two patients (29%) with adenomatous gastric polyps were positive for the infection. Complete eradication of H. pylori was initially achieved in all patients positive for H. pylori. Total regression of the gastric polyps was observed only among the patients with hyperplastic gastric polyps in whom H. pylori had been eradicated. Complete regression of the hyperplastic gastric polyps was observed in seven of the 16 evaluable patients (44%; 95% CI, 19-68%) after H. pylori eradication. The endoscopic snare polypectomy was carried out in nine patients with hyperplastic polyps and two patients with adenomatous gastric polyps in whom regression of the polyps was not observed after H. pylori eradication, as well as in five patients with hyperplastic and four with adenomatous gastric polyps who were negative for H. pylori. Exploratory laparotomy and gastrotomy with polyps excision were carried out in one patient with multiple adenomatous gastric polyps. In only one patient who was not positive for H. pylori recurrence of hyperplastic gastric polyp was recorded during follow-up, and no re-infection with H. pylori has been detected. CONCLUSIONS: Our results suggest that the development of hyperplastic gastric polyps may be directly related to chronic active gastritis and concomitant H. pylori infection. Cure of H. pylori infection associated with hyperplastic gastric polyps resulted in complete polyp regression in more than 40% of patients. Therefore, for patients with hyperplastic gastric polyps and concurrent H. pylori infection an antibiotic treatment designed to eradicate H. pylori appears to be recommended before further therapeutic options are consi


Assuntos
Pólipos Adenomatosos/complicações , Infecções por Helicobacter/complicações , Helicobacter pylori , Pólipos/complicações , Neoplasias Gástricas/complicações , Antibacterianos/uso terapêutico , Doença Crônica , Feminino , Gastrite/microbiologia , Infecções por Helicobacter/tratamento farmacológico , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Recidiva
11.
Acta Med Croatica ; 52(2): 133-8, 1998.
Artigo em Inglês | MEDLINE | ID: mdl-9682502

RESUMO

Medical therapy for reflux esophagitis is designed to provide symptom relief and esophageal healing, and to prevent complications. Life-style modifications serve as an adjunct to drug therapy. Histamine-H2-receptor antagonists and prokinetic agents promote symptom relief and esophageal healing in mild esophagitis, but are less effective in the treatment of moderate to severe esophagitis. For patients with moderate to severe esophagitis, rapid symptom relief and esophageal healing have been achieved with proton pump inhibitors. These patients usually require maintenance therapy with proton pump inhibitors.


Assuntos
Refluxo Gastroesofágico/terapia , Humanos
12.
Hepatogastroenterology ; 45(21): 684-90, 1998.
Artigo em Inglês | MEDLINE | ID: mdl-9684117

RESUMO

BACKGROUND/AIM: The occurrence of apoptotic cells was analyzed in human normal gastric mucosa, polyps and adenocarcinomas. METHODOLOGY: Histological classification was carried out on hematoxylin and eosin stained slides. The tissue was classified as follows: Normal gastric mucosa or adenomatous polyps. Gastric carcinoma specimens were histologically classified according to Lauren's classification into: A: Diffuse adenocarcinoma without metastasis, B: Diffuse adenocarcinoma with metastasis, C: Intestinal adenocarcinoma without metastasis, D: Intestinal adenocarcinoma with metastasis, E: Mixed adenocarcinoma without metastasis and mixed adenocarcinoma with metastasis. The counting of apoptotic cells was performed using the 40X objective with a calibrated eyepiece Weibel's multi-purpose M 42 stereological test system. Each group was evaluated stereologically, determining numeric density of apoptotic cells. RESULTS: The results show the progressive and statistically significant increase of apoptotic numeric densities from normal gastric epithelium to adenomatous polyp and finally to cancer, which contained the highest number of apoptotic cells. Comparing gastric carcinoma with and without metastasis in intestinal and diffuse adenocarcinoma there was statistically significant difference. In these two groups, carcinomas with metastasis contained higher number of apoptotic cells than without metastasis. Gastric cancer according to numeric densities of apoptotic cells can be separated in tree statistically different groups: A: Intestinal type gastric cancer with metastasis (the highest number of apoptotic cells), B: Intestinal type gastric cancer without metastasis and diffuse gastric cancer with metastasis (medium number), C: Diffuse type gastric cancer without metastasis, mixed gastric cancer with and without metastasis (the lowest number of apoptotic cells). CONCLUSION: These results suggest that numeric densities of apoptotic cells are associated with tumor progression in human gastric carcinogenesis and can be used as prognostic mark.


Assuntos
Adenocarcinoma/patologia , Apoptose , Pólipos/patologia , Neoplasias Gástricas/patologia , Idoso , Feminino , Mucosa Gástrica/patologia , Humanos , Masculino , Pessoa de Meia-Idade , Prognóstico
14.
Coll Antropol ; 22(2): 515-24, 1998 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-9887608

RESUMO

In studying anatomical samples of both inguinal hernia patients and healthy controls with no changes observable in the inguinal region, the authors aimed at investigating the constitution of the inguinal region in relation to the formation of inguinal hernia. The morphological investigation of 68 anatomical samples and 44 inguinal regions at autopsy, revealed that the length of the interspinal line, independent of sex, varies from 180 to 310 mm and is 63 to 132 mm removed from the pubic tubercle (the height of the anterior pelvic arch). Thus, in 35% of male and 22% of female subjects the height of the anterior pelvic arch exceeded 75 mm indicating a low position of the groin. The research carried out in 640 inguinal hernia patients and 186 controls indicated a shift towards higher values in the interspinal line in inguinal hernia patients as compared with the controls. In addition, the height of the anterior pelvic arch in patients with inguinal hernia conspicuously exceeded that observed in the controls. The present study undoubtedly shows that the number of muscle and connective structure variations of the inguinal region depends upon the position of the groin in relation to the interspinal plane. The authors therefore agree with the classification of these relationships to high, medial and low groin position. The high position of the pubic tubercles up to 75 mm removed from the interspinal spine is accompanied with the firm constitution of the entire inguinal region. Moreover, the medical position of pubic tubercles 75 to 90 mm removed from the interspinal line does not indicate the risk of developing inguinal hernia. On the other hand, the low position of the pubic tubercles more than 90 mm removed from the interspinal line is often due to the inferior constitution of the inguinal region. This group is regularly at higher risk of developing inguinal hernia, particularly with other risk factors being added as well. The identification of structural characteristics of the inguinal region therefore enables the selection of the most appropriate operation procedure, i.e. between the classic hernia repair and endoscopic approach for prosthetic mesh implantation.


Assuntos
Virilha/anatomia & histologia , Hérnia Inguinal/patologia , Feminino , Virilha/patologia , Humanos , Masculino , Osso Púbico/anatomia & histologia , Osso Púbico/patologia
15.
Acta Med Croatica ; 51(4-5): 181-9, 1997.
Artigo em Inglês | MEDLINE | ID: mdl-9473796

RESUMO

The role of physical parameters such as light intensity, irradiation time, light wave-length and photoactive substance concentration during photodynamic therapy is discussed. Optimal values for all these parameters were determined in a well defined biological model based on the treatment of CMC-2 fibrosarcoma implanted in the right hind leg of CBA/HZgr mice.


Assuntos
Antineoplásicos/administração & dosagem , Éter de Diematoporfirina/administração & dosagem , Fibrossarcoma/tratamento farmacológico , Fotoquimioterapia , Animais , Luz , Camundongos , Camundongos Endogâmicos CBA , Transplante de Neoplasias , Doses de Radiação , Fatores de Tempo
16.
Food Addit Contam ; 13(8): 929-38, 1996.
Artigo em Inglês | MEDLINE | ID: mdl-8950113

RESUMO

The effect of gamma-irradiation on fumonisin B1 (FB1) and fumonisin B2 (FB2) occurring in maize materials has been investigated together with the stability of fumonisins in gamma-irradiated maize stored at different temperatures (-18 to +40 degrees C) for different periods (2, 4, 13 and 26 weeks). Fifteen KGy gamma-irradiation was required to sterilize efficiently maize flour. This process caused a decrease in fumonisin content of about 20%. The stability studies showed that fumonisins are stable in gamma-irradiated maize for at least 6 months at 25 degrees C or at least 4 weeks at 40 degrees C. These data indicate that gamma-irradiation is an appropriate technique for obtaining sterilized maize materials to be used for intercomparison studies on analytical procedures for the measurement of the fumonisin content.


Assuntos
Ácidos Carboxílicos/efeitos da radiação , Carcinógenos Ambientais/efeitos da radiação , Fumonisinas , Raios gama , Zea mays/efeitos da radiação , Ácidos Carboxílicos/análise , Carcinógenos Ambientais/análise , Cromatografia Líquida de Alta Pressão/métodos , Estabilidade de Medicamentos , Armazenamento de Medicamentos , Contaminação de Alimentos/análise , Temperatura
17.
Food Addit Contam ; 13(8): 909-27, 1996.
Artigo em Inglês | MEDLINE | ID: mdl-8950112

RESUMO

The results of an intercomparison study for the analysis of fumonisin B1 (FB1) and fumonisin B2 (FB2) in a contaminated maize material (Maize B, containing approximately 2 micrograms/g FB1 and 1 micrograms/g FB2) and its 'blank' counterpart (Maize A, containing less than 20 ng/g FB1 and FB2) are reported. Maize materials were distributed in 60 g sachets, submitted to gamma-irradiation at 15 kGy, and distributed to participating laboratories. The study was carried out by 24 European laboratories, most of which have national or international responsibilities for food/feed quality control. Participants used basically one method with some modifications, based on clean-up through SAX minicolumn and reversed phase HPLC with fluorescence detection of the OPA-fumonisin derivatives. The intercomparison study generated data (after correction for recoveries) with repeatability and reproducibility levels of: RSDr = 10% and RSDR = 11% for FB1; RSDr = 11% and RDSR = 13% for FB2. The recoveries obtained by most participants were considered low (70% for FB1 and 69% for FB2), being considerably affected by the extraction mode. Average recoveries for laboratories using blending were 62% and 60%, whereas for laboratories using shaking they were 85% and 86% for FB1 and FB2, respectively. The day-to-day- data showed a between-day, within-laboratory repeatability lower than 15% (CV < 15%) for FB1 for all laboratories, whereas only three laboratories obtained a between-day, within-laboratory reproducibility higher than 15% (CV > 15%) for FB2.


Assuntos
Ração Animal/análise , Ácidos Carboxílicos/análise , Carcinógenos Ambientais/análise , Fumonisinas , Zea mays , Cromatografia Líquida de Alta Pressão/métodos , Europa (Continente) , Contaminação de Alimentos/análise , Controle de Qualidade , Padrões de Referência
18.
Acta Med Croatica ; 50(3): 119-24, 1996.
Artigo em Inglês | MEDLINE | ID: mdl-8890527

RESUMO

The effect of different local temperature increase in normal and tumorous tissue, influenced by red light commonly used in photodynamic therapy, on tumor growth rate was reanalyzed, taking into account the tumor tissue penetration depth of the light used. The rear part of the tumor is definitely not receiving the same light dose, and consequently the same amount of heat energy, as the front part. The effect is taken into account by using a mathematical model of tumor growth for the rear part of the tumor. Positive experimental results of hyperthermia due to the energy deposited by the red light, are more encouraging after such a correction than previously reported.


Assuntos
Fibrossarcoma/patologia , Fototerapia , Animais , Feminino , Fibrossarcoma/induzido quimicamente , Fibrossarcoma/terapia , Hipertermia Induzida , Masculino , Camundongos , Camundongos Endogâmicos , Modelos Biológicos , Modelos Teóricos , Transplante de Neoplasias
19.
J Food Prot ; 59(8): 893-897, 1996 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31159117

RESUMO

The performance of an experimental polyclonal antibody (PAb)-based competitive direct enzyme-linked immunosorbent assay (CD-ELISA) developed for the analysis of fumonisins in corn was assessed by comparison with an established high-performance liquid chromatography (HPLC) method. The comparative study was conducted using a series of 20 corn samples naturally contaminated with combined fumonisin levels ranging from <0.05 to >5 µg/g (ppm). Linear regression analysis between the results generated by HPLC and CD-ELISA provided correlation coefficients (r) and regression slopes (b) of r = 0.960, b = 1.493 (P < 0.001); r = 0.865, b = 3.903 (P < 0.001); and r = 0.832, b = 0.107 (P < 0.001) for the individual fumonisins B1 (FB1), B2 (FB2) and B3 (FB3), respectively, while corresponding values of r = 0.967, b = 1.059 (P < 0.001) were obtained for the combined FB1, FB2, and FB3 concentrations. In 3 of 18 fumonisin-positive corn samples, combined fumonisin levels determined by CD-ELISA were between 85 and 100% higher than those determined in the same extracts by HPLC, while in 13 other samples, CD-ELISA results were between 1.8 and 53% higher than those determined by HPLC. Conversely, in 2 of 18 samples, CD-ELISA results were lower than those determined by HPLC. The differences recorded between HPLC and the experimental PAb-based CD-ELISA were far less than those previously recorded for other mono- and polyclonal antibody-based CD-ELISA systems. The results indicate that the experimental PAb-based CD-ELISA may be effectively applied for the initial screening for fumonisins in corn.

20.
Nat Toxins ; 3(4): 269-74; discussion 280, 1995.
Artigo em Inglês | MEDLINE | ID: mdl-7582628

RESUMO

Fumonisins are mycotoxins mainly produced by Fusarium moniliforme, one of the most prevalent seed-borne fungi of maize. Strains of Fusarium moniliforme isolated from cereals in Europe produced in cultures high levels (up to 4 mg/g) of fumonisins B1 and B2 (FB1 and FB2). FB1 and FB2 have been found in maize and maize-based foods and feeds in most European countries. In Italy these mycotoxins have been directly involved in a fatal outbreak of equine leukoencephalomalacia, and have been found at different levels in most maize-based food products, including polenta--a staple food in a region with high incidence of esophageal cancer. The European Commission, Community Bureau of Reference (BCR) and Measurements and Testing Programme (M&T), has undertaken two consecutive intercomparison studies, involving over 20 laboratories from 12 European countries, to improve the quality of fumonisins analysis at European level. The first study consisted in the evaluation of the determination of fumonisins in an unknown solution, while the second one involved the analytical methodology for fumonisins in contaminated and blank maize samples. A definite improvement in the performance of the different laboratories has been observed in the second study. In view of the production of reference materials certified for their fumonisins contents, new analytical procedures need to be developed.


Assuntos
Microbiologia de Alimentos , Fumonisinas , Micotoxinas/análise , Zea mays/química , Genótipo , Padrões de Referência
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