Acute intake of fructooligosaccharide and partially hydrolyzed guar gum on gastrointestinal transit: A randomized crossover clinical trial.

OBJECTIVES: Dietary fibers, such as fructooligosaccharide (FOS) and partially hydrolyzed guar gum (PHGG) have several gastrointestinal functions. The aims of this study were to evaluate the effect of acute ingestion of FOS and PHGG on the percentage of gastric emptying and small intestinal transit and to evaluate the effect of these dietary fibers on the levels of intestinal hormones-active glucagon-like peptide-1, pancreatic polypeptide, and gastric inhibitory peptide-and their effect on feelings of hunger and satiety and the desire to eat. METHODS: In this crossover, randomized controlled clinical trial, we compared the effects of these two fibers on gastrointestinal transit. The tests were performed using scintigraphy. On three different days, healthy participants consumed a test meal containing 20 g of digestible maltodextrin (placebo), 20 g of FOS, or 20 g of PHGG. RESULTS: The gastric emptying of the FOS-based diet (84.2 ± 9.4%) within 2 h was statistically increased compared with the placebo and PHGG-based diets (78 ± 10.2% and 74 ± 15.3%, respectively; P < 0.05). However, a reduction in small intestinal transit was observed after consumption of both FOS- and PHGG-based diets (28.5 ± 15.56% and 24.2 ± 13.7%, respectively) compared with the placebo diet (41.20 ± 15.4%; P < 0.05). There were no changes in the levels of intestinal hormones, feeling of hunger and satiety, or desire to eat after consuming the three diets (P > 0.05). CONCLUSION: The acute intake of FOS increased gastric emptying, whereas both FOS and PHGG reduced small intestine transit without altering the levels of intestinal hormones, hunger feelings and satiety, or the desire to eat.

Sympathetic Dysautonomia in Heart Failure by 123I-MIBG: comparison between Chagasic, non-Chagasic and heart transplant patients.

BACKGROUND: Heart failure (HF) is a severe public health problem because of its high morbidity and mortality and elevated costs, thus requiring better understanding of its course. In its complex and multifactorial pathogenesis, sympathetic hyperactivity plays a relevant role. Considering that sympathetic dysfunction is already present in the initial phases of chronic Chagas cardiomyopathy (CCC) and frequently associated with a worse prognosis, we assumed it could be more severe in CCC than in cardiomyopathies of other etiologies (non-CCC). OBJECTIVES: To assess the cardiac sympathetic dysfunction 123I-MIBG) of HF, comparing individuals with CCC to those with non-CCC, using heart transplant (HT) patients as denervated heart parameters. METHODS: We assessed 76 patients with functional class II-VI HF, being 25 CCC (17 men), 25 non-CCC (14 men) and 26 HT (20 men), by use of cardiac 123I-metaiodobenzylguanidine 123I-MIBG) scintigraphy, estimating the early and late heart-to-mediastinum ratio (HMR) of 123I-MIBG uptake and cardiac washout (WO%). The 5% significance level was adopted in the statistical analysis. RESULTS: The early and late HMR values were 1.73 ± 0.24 and 1.58 ± 0.27, respectively, in CCC, and 1.62 ± 0.21 and 1.44 ± 0.16 in non-CCC (p = NS), being, however, higher in HT patients (p < 0.001). The WO% values were 41.65 ± 21.4 (CCC), 47.37 ± 14.19% (non-CCC) and 43.29 ± 23.02 (HT), p = 0.057. The late HMR values showed a positive weak correlation with left ventricular ejection fraction (LVEF) in CCC and non-CCC (r = 0.42 and p = 0.045; and r = 0.49 and p = 0.015, respectively). CONCLUSION: Sympathetic hyperactivity 123I-MIBG) was evidenced in patients with class II-IV HF, LVEF < 45%, independently of the HF etiology, as compared to HT patients.

Sympathetic Dysautonomia in Heart Failure by 123I-MIBG: comparison between Chagasic, non-Chagasic and heart transplant patients / Disautonomia Simpática na Insuficiência Cardíaca pela 123I-MIBG: Comparação entre Pacientes Chagásicos, não-Chagásicos e Transplantados Cardíacos

Abstract Background: Heart failure (HF) is a severe public health problem because of its high morbidity and mortality and elevated costs, thus requiring better understanding of its course. In its complex and multifactorial pathogenesis, sympathetic hyperactivity plays a relevant role. Considering that sympathetic dysfunction is already present in the initial phases of chronic Chagas cardiomyopathy (CCC) and frequently associated with a worse prognosis, we assumed it could be more severe in CCC than in cardiomyopathies of other etiologies (non-CCC). Objectives: To assess the cardiac sympathetic dysfunction 123I-MIBG) of HF, comparing individuals with CCC to those with non-CCC, using heart transplant (HT) patients as denervated heart parameters. Methods: We assessed 76 patients with functional class II-VI HF, being 25 CCC (17 men), 25 non-CCC (14 men) and 26 HT (20 men), by use of cardiac 123I-metaiodobenzylguanidine 123I-MIBG) scintigraphy, estimating the early and late heart-to-mediastinum ratio (HMR) of 123I-MIBG uptake and cardiac washout (WO%). The 5% significance level was adopted in the statistical analysis. Results: The early and late HMR values were 1.73 ± 0.24 and 1.58 ± 0.27, respectively, in CCC, and 1.62 ± 0.21 and 1.44 ± 0.16 in non-CCC (p = NS), being, however, higher in HT patients (p < 0.001). The WO% values were 41.65 ± 21.4 (CCC), 47.37 ± 14.19% (non-CCC) and 43.29 ± 23.02 (HT), p = 0.057. The late HMR values showed a positive weak correlation with left ventricular ejection fraction (LVEF) in CCC and non-CCC (r = 0.42 and p = 0.045; and r = 0.49 and p = 0.015, respectively). Conclusion: Sympathetic hyperactivity 123I-MIBG) was evidenced in patients with class II-IV HF, LVEF < 45%, independently of the HF etiology, as compared to HT patients.

Resumo Fundamentos: A insuficiência cardíaca (IC) representa um grave problema de saúde pública pela alta morbimortalidade e custos envolvidos, exigindo uma melhor compreensão de sua evolução. Em sua patogênese, complexa e multifatorial, a hiperatividade simpática ocupa relevante papel. Considerando que a disfunção simpática está presente já nas fases iniciais da cardiopatia chagásica crônica (CCC), frequentemente associando-se a um pior prognóstico, supomos que pudesse ser mais grave na CCC que nas demais etiologias (não-CCC). Objetivos: Avaliar a disfunção simpática cardíaca (123I-MIBG) da IC, comparando-se os portadores de CCC aos não-CCC, utilizando os pacientes transplantados cardíacos (TC) como parâmetro de coração desnervado. Métodos: Estudamos 76 pacientes com IC classe funcional II-VI, sendo 25 CCC (17 homens), 25 não-CCC (14 homens) e 26 TC (20 homens), pela cintilografia cardíaca (123I-MIBG), estimando-se a captação (HMR) precoce e tardia e o washout cardíaco (Wc%). Nas análises estatísticas, o nível de significância foi de 5%. Resultados: Os valores da HMR precoce e da tardia foram 1,73 ± 0,24 e 1,58 ± 0,27, respectivamente, na CCC, e 1,62 ± 0,21 e 1,44 ± 0,16 na não-CCC (p = NS), sendo, porém, mais elevados nos TC (p < 0,001). Os valores de Wc% foram 41,65 ± 21,4 (CCC), 47,37 ± 14,19% (não-CCC) e 43,29 ± 23,02 (TC), p = 0,057. Os valores de HMR tardia apresentaram correlação positiva fraca com a fração de ejeção de ventrículo esquerdo (FEVE) na CCC e na não-CCC (r = 0,42 e p = 0,045; e r = 0,49 e p = 0,015, respectivamente). Conclusão: Evidenciou-se a presença de hiperatividade simpática (123I-MIBG) em pacientes com IC classe II-IV, FEVE < 45%, independentemente da etiologia da IC, quando comparados aos pacientes TC.

Long-Circulating and pH-Sensitive Liposome Preparation Trapping a Radiotracer for Inflammation Site Detection.

Inflammatory and infectious diseases are one of the most common causes of mortality and morbidity. This paper aimed to prepare and to evaluate the ability of long-circulating and pH-sensitive liposomes, trapping a radiotracer, to identify inflamed focus. The physicochemical characterization of freeze-dried liposomes, using glucose as cryoprotectant, showed 80% of the vesicles with adequate mean diameter and good vesicle size homogeneity. Radiotracer encapsulation percentage in liposomes was 10.65%, of which 4.88% was adsorbed on the surface of the vesicles. Furthermore, liposomes presented positive zeta potential. Freeze-dried liposomes, stored for 180 days at 4 degrees C, did not show significant changes in the mean diameter, indicating good stability. Free radiotracer and radiolabeled liposomes were injected into inflammation focus-bearing rats, and ex-vivo biodistribution studies and scintigraphic images were performed. Results showed that radiopharmaceutical, free and encapsulated into liposomes, were able to identify the inflamed site. Target/non-target ratios, obtained by scintigraphic images, were greater than 1.5 at all investigated times. Data did not show significant differences between the free radiotracer and radiolabeled liposomes. Results suggest that this liposomal preparation could be employed as an alternative procedure for inflamed site detection by means of scintigraphic images. However, as the radiotracer is adsorbed onto the liposome surface by electrostatic forces, it is suggested that a neutral radiopharmaceutical be used to confirm the potential of this formulation as a scintigraphic probe for inflammation/infection detection.

Bombesin Encapsulated in Long-Circulating pH-Sensitive Liposomes as a Radiotracer for Breast Tumor Identification.

Bombesin (BBN) is a tetradecapeptide that binds specifically to gastrin-releasing peptide receptors in humans. These receptors are over-expressed in several forms of cancer; radiolabeled BBN could therefore be used to detect such cancers. However, the degradation of peptides is a critical issue in the development of tumor tracers. Liposomes can be used to overcome this problem and improve the uptake of tracers by tumors. Therefore, the purpose of this study was to prepare and characterize long-circulating and pH-sensitive liposomes (SpHL) containing 99mTc-HYNIC-ßAla-Bombesin(7-14) (99mTc-BBN(7-14). In addition, the ability of this system to identify human breast cancer tissue was evaluated using biodistribution studies and scintigraphic images. Long-circulating and pH-sensitive liposomes (SpHL) were prepared and freeze-dried in the presence of cryoprotectants (glucose, mannitol, and trehalose). They were subsequently reconstituted with a solution of 99mTc-HYNIC-ßAla-Bombesin(7-14) (99mTc-BBN(7-14)). The liposomes were evaluated for size, encapsulation percentage, radiotracer leakage, and storage stability. In addition, in vivo studies were performed in breast tumor-bearing nude mice. Liposomes in the presence of glucose (SpHLG), exhibited a mean diameter of 164.5 ± 6.5 nm and exhibited a 99mTc-BBN(7-14) encapsulation percentage of 30%. In addition, they remained highly stable for up to 120 days of storage. SpHLG- 99mTc-BBN(7-14) showed longer blood circulation than free 99mTc-BBN(7-14), did. The tumor-to-muscle and tumor-to-blood ratios for SpHLG-99mTc-BBN(7-14 were high at 4 h post-injection (9.31%ID/g and 7.93%ID/g, respectively). Furthermore, scintigraphic images revealed a strong signal in the tumor area, indicating tumor specificity of SpHLG-99mTc-BBN(7-14). In summary, SpHLG-99mTc-BBN(7-14) presented characteristics suitable for a diagnostic agent, and is a potential tool for tumor identification.

Preliminary study of coconut water for graft tissues preservation in transplantation.

OBJECTIVE: to verify the effectiveness of coconut water in preserving tissues for transplant. METHODS: Fifty male Wistar rats were randomly distributed in five groups, according to the following preservation solutions for tissue grafts: Group 1: Lactated Ringer; Group 2: Belzer solution; Group 3: mature coconut water; Group 4: green coconut water; Group 5: modified coconut water. In Group 5, the green coconut water has been modified like the Belzer solution. From each animal we harvested the spleen, ovaries and skin of the back segment. These tissues were preserved for six hours in one of the solutions. Then, the grafts were reimplanted. The recovery of the function of the implanted tissues was assessed 90 days after surgery, by splenic scintigraphy and blood exam. The implanted tissues were collected for histopathological examination. RESULTS: The serum levels did not differ among groups, except for the animals in Group 5, which showed higher levels of IgG than Group 1, and differences in relation to FSH between groups 1 and 2 (p <0.001), 4 and 2 (p = 0.03) and 5 and 2 (p = 0.01). The splenic scintigraphy was not different between groups. The ovarian tissue was better preserved in mature coconut water (p <0.007). CONCLUSION: the coconut water-based solutions preserves spleen, ovary, and rat skin for six hours, maintaining their normal function.

Preliminary study of coconut water for graft tissues preservation in transplantation / Estudo preliminar da água de coco para preservação de enxertos teciduais em transplante

OBJECTIVE: To verify the effectiveness of coconut water in preserving tissues for transplant. METHODS: Fifty male Wistar rats were randomly distributed in five groups, according to the following preservation solutions for tissue grafts: Group 1: Lactated Ringer; Group 2: Belzer solution; Group 3: mature coconut water; Group 4: green coconut water; Group 5: modified coconut water. In Group 5, the green coconut water has been modified like the Belzer solution. From each animal we harvasted the spleen, ovaries and skin of the back segment. These tissues were preserved for six hours in one of the solutions. Then, the grafts were reimplanted. The recovery of the function of the implanted tissues was assessed 90 days after surgery, by splenic scintigraphy and blood exame. The implanted tissues were collected for histopathological examination. RESULTS: The serum levels did not differ among groups, except for the animals in Group 5, which showed higher levels of IgG than Group 1, and differences in relation to FSH between groups 1 and 2 (p <0.001), 4 and 2 (p = 0.03) and 5 and 2 (p = 0.01). The splenic scintigraphy was not different between groups. The ovarian tissue was better preserved in mature coconut water (p <0.007). CONCLUSION: the coconut water-based solutions preserves spleen, ovary, and rat skin for six hours, maintaining their normal function.

OBJETIVO: Verificar a eficácia da água de coco na preservação de tecidos para transplante. MÉTODOS: cinquenta ratas Wistar foram distribuídas aleatoriamente em cinco grupos, de acordo com as seguintes soluções de preservação para enxertos teciduais: Grupo 1- Ringer lactato, Grupo 2- Solução de Belzer, Grupo 3- Água de coco maduro, Grupo 4- Água de coco verde, Grupo 5- Água de coco modificada. No Grupo 5, a água de coco verde foi modificada à semelhança da solução de Belzer. De cada animal, retirou-se o baço, os ovários e um segmento de pele do dorso. Esses tecidos foram preservados durante seis horas em uma das soluções. Em seguida, os enxertos foram reimplantados. A recuperação da função dos tecidos implantados foi avaliada 90 dias após a cirurgia, por meio de cintilografia esplênica, exames de sangue. Os tecidos implantados foram coletados para estudo anatomopatológico. RESULTADOS: as dosagens séricas não apresentaram diferença entre os cinco grupos, exceto pelos animais do Grupo 5, que apresentaram valores mais elevados de IgG do que o Grupo 1,e pelas diferenças em relação ao FSH entre os grupos 1 e 2 (p<0,001), 4 e 2 (p=0,03), 5 e 2 (p=0,01). A cintilografia esplênica não foi diferente entre os grupos. O tecido ovariano foi melhor preservado em água de coco maduro (p<0,007). CONCLUSÃO: as soluções à base de água de coco preservam baço, ovário e pele de rato durante seis horas, mantendo sua função normal.

Long-circulating, pH-sensitive liposomes versus long-circulating, non-pH-sensitive liposomes as a delivery system for tumor identification.

Bombesin (BBN) is a tetradecapeptide that binds specifically to gastrin-releasing peptide receptors in humans. Several forms of cancer, including lung, prostate, breast, and colon over-express receptors for bombesin-like peptides. Therefore, radiolabeled bombesin analogs might be useful for tumor identification. Nevertheless, it is well known that higher tumor uptake can yield images in higher quality. Hence, drug delivery systems, such as liposomes, can be used to achieve a higher concentration of radiotracer in tumor site, and also improve the radiotracer stability, since peptides can suffer easily degradation in vivo by natural plasma and tissue peptides. In this paper, we prepared long-circulating, pH-sensitive liposomes and long-circulation, non-pH sensitive liposomes. Both formulations were able to encapsulate the radiolabeled bombesin derivative (99mTc-BBN(7_14)), and also showing high in vitro stability. Biodistribution studies were performed in Ehrlich tumor bearing-mice to compare the ability of pH-sensitive and non-pH sensitive liposomes to deliver 99mTc-BBN(7_14) to tumor site. Results showed higher tumor uptake (2-fold) when pH-sensitive liposomes were used, suggesting that these vesicles can facilitate the access to the tumor by releasing the diagnostic agent into the ideal area. As a result, tumor-to-muscle ratio achieved with pH-sensitive liposomes was higher than that obtained with non-pH-sensitive formulation. In addition, scintigraphic images for pH-sensitive liposomes showed evident tumor uptake, corroborating with biodistribution data. Therefore, the results presented in this paper suggest that pH-sensitive liposomes are able to deliver more efficiently the radiolabeled bombesin analog. This finding poses a new possibility to improve images quality, since the tumor-to-muscle ratio was strongly enhanced.

Kit formulation for 99mTc-labeling of HYNIC-ßAla-Bombesin((7-14)).

Bombesin (BBN) is a tetradecapeptide that binds specifically to gastrin-releasing peptide receptors. Several forms of cancer, including lung, prostate, breast, and colon express receptors for bombesin-like peptides. Radiolabeled BBN analogs with a high affinity for these receptors might be used for scintigraphic imaging. Kit formulations for labeling these molecules are important for routine preparation. A freeze-dried kit for labeling HYNIC-ßAla-Bombesin((7-14)) with technetium-99m was prepared, and its storage stability was evaluated by in vitro and in vivo assays.

Tumor bombesin analog loaded long-circulating and pH-sensitive liposomes as tool for tumor identification.

Long-circulating and pH-sensitive liposomes trapping (99m)Tc-HYNIC-ßAla-bombesin((7-14)) (aSpHL-(99m)Tc-BBN((7-14))) were successfully prepared. Biodistribution studies and scintigraphic images were performed in Ehrlich tumor-bearing Swiss mice. This system showed high accumulation in tumor tissue with high tumor-to-muscle ratio. Therefore, aSpHL-(99m)Tc-BBN((7-14)) could be considered as a potential agent for tumor diagnosis.

Biodistribution and antitumoral effect of long-circulating and pH-sensitive liposomal cisplatin administered in Ehrlich tumor-bearing mice.

Cisplatin (CDDP) is one of the most active cytotoxic agents and has been widely used in the treatment of peritoneal carcinomatosis by the intraperitoneal (i.p.) route. However, CDDP, a low-molecular-weight compound, is rapidly absorbed by the capillaries in the i.p. serosa and transferred to the bloodstream, inducing the appearance of systemic side-effects, such as nephrotoxicity. Furthermore, the i.p. CDDP chemotherapy is limited to patients whose residual tumor nodules are less than 0.5 cm in diameter after surgical debulking. The failure of i.p. therapy is attributed to the poor penetration of CDDP into larger tumors. One strategy to improve drug delivery in the peritoneal region and reduce toxicity is the use of drug delivery systems. The objective of the present work was to evaluate the biodistribution and antitumoral effect of long-circulating and pH-sensitive liposomes containing CDDP (SpHL-CDDP), as compared with free CDDP, after their i.p. administration in Ehrlich ascitic tumor-bearing mice. After administering a 6 mg/kg single i.p. bolus injection of either free CDDP or SpHL-CDDP, ascitic fluid (AF), blood and organs (kidneys, liver, spleen and lungs) were collected and analyzed for CDDP content. The area under the CDDP concentration-time curve (AUC) obtained for AF and blood after SpHL-CDDP administration was 3.3-fold larger and 1.3-fold lower, respectively, when compared with free CDDP treatment, thus indicating its high retention within the peritoneal cavity. The determination of the ratio between AUC in each tissue and that in blood (Kp) showed a lower accumulation of CDDP in kidneys after SpHL-CDDP treatment. The SpHL-CDDP treatment demonstrated a significant uptake by the liver and spleen. SpHL-CDDP treatment led to a higher survival rate of mice with initial or disseminated peritoneal carcinomatosis than CDDP treatment. These results indicate that SpHL-CDDP may be useful for i.p. chemotherapy due to their greater concentration in the peritoneal cavity.

Bombesin derivative radiolabeled with technetium-99m as agent for tumor identification.

A bombesin derivative was successfully radiolabeled in high labeling yield. Biodistribution studies and scintigraphic images in Ehrlich tumor-bearing mice were performed. This compound showed high accumulation in tumor tissue with high tumor-to-muscle and tumor-to-blood ratios. Thus, (99m)Tc-HYNIC-Bombesin((7-14)) could be used as an agent for tumor diagnosis.

A novel D-glucose derivative radiolabeled with technetium-99m: synthesis, biodistribution studies and scintigraphic images in an experimental model of Ehrlich tumor.

A d-glucose-MAG(3) derivative was successfully synthesized and radiolabeled in high labeling yield. Biodistribution studies and scintigraphic images in Ehrlich tumor-bearing mice were performed. This compound showed high accumulation in tumor tissue with high tumor-to-muscle ratio. Thus, d-glucose-MAG(3) could be considered as agent for tumor diagnosis.

Synthesis and biodistribution studies of carbohydrate derivatives radiolabeled with technetium-99m.

Three carbohydrate derivatives, MAG(3)-Gl, MAG(3)-Ga, MAG(3)-NG, were synthesized and radiolabeled in high yields. These substances were injected in health Swiss mice and their biodistribution were evaluated. Among them, (99m)Tc-MAG(3)-Ga displayed higher accumulation in hepatic tissue, due to the presence of specific receptors in the liver for this carbohydrate. Thus, the use of (99m)Tc-MAG(3)-Ga to assess hepatic function can be considered.

Synthesis and biological evaluation of technetium-labeled D-glucose-MAG3 derivative as agent for tumor diagnosis.

A d-glucose-MAG(3) derivative was successfully synthesized and radiolabeled in high labeling yield. Biodistribution studies in Ehrlich tumor-bearing mice were performed. This compound showed high accumulation in tumor tissue with high tumor-to-muscle ratio and moderate tumor-to-blood ratio. Thus, d-glucose-MAG(3) is a potential agent for tumor diagnosis.

Technetium-99m-labeled stealth pH-sensitive liposomes: a new strategy to identify infection in experimental model

The diagnosis of inflammatory and infectious processes is an important goal in medicine. The use of radiopharmaceuticals for identification of inflammation and infection foci has received considerable attention. The aim of this work was to evaluate the uptake and the imaging potential of stealth pH-sensitive liposomes radiolabelled with 99mTechnetium (99mTc) to identify infection sites in mice. The liposomes containing glutathione were labeled with 99mTc-Hexamethylpropyleneamine oxime (HMPAO) complex. The 99mTc-labeled stealth pH-sensitive liposomes (99mTc-SpHL) were injected in mice bearing infection in the right thigh muscle induced by Staphylococcus aureus. Biodistribution studies and scintigraphic imaging were performed at different times after injection of radiopharmaceutical. The 99mTc-SpHL was significantly uptaken by abscess when compared to the respective control. The abscess was visualized as early as 0.5 hours after injection of 99mTc-SpHL becoming more prominent with the time. These results indicate that 99mTc-SpHL is a promising radiopharmaceutical for visualizing infection foci in patients.

O diagnóstico de processos inflamatórios e infecciosos é um objetivo importante em medicina. O uso de radiofármacos para identificação de focos de inflamação e infecção tem recebido considerável atenção. O objetivo deste trabalho foi avaliar a captação e o potencial de imagem de lipossomas pH-sensíveis furtivos radiomarcados com 99mTecnécio (99mTc) para identificar sítios de infecção em camundongos. Os lipossomas contendo glutationa foram marcados com o complexo 99mTc-hexametilpropilenoamina oxima (HMPAO). Os lipossomas pH-sensíveis furtivos marcados com 99mTc (99mTc-LpHS) foram injetados em camundongos com infecção induzida por Staphylococcus aureus no músculo da coxa direita. Estudos de biodistribuição e imagem cintilográfica foram realizados em diferentes tempos após injeção do radiofármaco. Os 99mTc-LpHS foram captados significativamente pelo abscesso quando comparado ao respectivo controle. O abscesso foi visualizado rapidamente (0,5 horas) após injeção do 99mTc-LpHS tornando-se mais evidenciado com o tempo. Estes resultados indicam que 99mTc-LpHS é um promissor radiofármaco para identificação de focos inflamatórios e infecciosos em pacientes.