'Anting' as food preparation : formic acid is worse on an empty stomach

Anting is a behavior common among passerine birds, yet its function is unknown. The behavior consists of a highly stereotyped set of movements which start when a bird picks up an ant, usually one which sprays formic acid as a defense, and sweeps it with frenzied motions through its feathers. The bird will often also eat the ant. As formic acid is toxic, we have tested the food-preparation hypothesis, that is, that the birds are anting to remove a distasteful or toxic substance from the ant before eating it. In a pair of experiments on starlings, Sturnus vulgaris, we have found evidence in support of this hypothesis.

Studies on dietary fibre : analysis, epidemiological and physiological aspects

This thesis involves an investigation in three areas; first, a study of an enzymatic-gravimetric method for the analysis of dietary fibre; second, a survey of dietary fibre intake in an area of a developing country, and finally, some observations on the functional aspects of gel-forming dietary fibre in the rat. A simple and rapid enzymatic-gravimetric assay for both soluble and insoluble dietary fibre has been critically investigated. Reference samples were also analysed by a more comprehensive, enzymatic gas chromatographic method to allow testing of the relative accuracy of the enzymatic-gravimetric method. The enzymatic-gravimetric method was found to be highly reproducible but gave a slightly higher value for total dietary fibre than the more comprehensive method. This discrepancy is probably due to the presence of small quantities of resistant starch and protein residue which are recovered in the enzymatic-gravimetric method. In the enzymatic-gas chromatographic method, protein residue is not measured, and resistant starch is estimated, but not counted as dietary fibre. The enzymatic-gravimetric method was applied to the analysis of foods commonly consumed in the Padang region of West Sumatra in Indonesia, in order to estimate dietary fibre intake in the region. Daily intakes of usual foods were estimated by use of a 24-hour recall procedure aided by food photographs to assist in the estimation of portion size. Samples of approximately 60 of the most commonly consumed foods were collected and analysed for dietary fibre. These appear to be the first data which report values for dietary fibre in Indonesion foods and they represent a significant improvement upon the existing data on crude fibre content. Knowledge of the amounts of foods usually consumed and their dietary fibre content allowed an estimation of usual intakes of dietary fibre. Fibre intake was found to be lower than in the developing countries of Africa and was comparable to intakes measured in the U.K. This is the first study to show that in this part of South East Asia, a developing country area using polished rice as a staple food, dietary fibre intakes are as low as in Western countries. Low intakes of fibre are believed to be related to the prevalence of a range of diseases and, in this study, preliminary data on the rates of non-infective, chronic diseases were collected from the two main hospitals in West Sumatra. Chronic, non-infectious diseases such as inguinal hernia, appendicitis, haemorrhoids, diabetes mellitus, hypertension and malignant neoplasms of the rectum are relatively frequent in West Sumatra. While no firm conclusions can be drawn from these data, they do show the possibility of a relationship between low intakes of dietary fibre and the prevalence of these diseases, and suggest that further investigation is necessary. Some observations were made of the effect of gel-forming dietary fibre on stomach emptying and intestinal transit rate in the rat. Xanthan gum was added to iso-osmotic solutions to produce increased viscosity and phenol sulphonphthalein (phenol red) was used as a non-absorbable marker. Gavage feeding of solutions with a range of viscosities was used to study the effect of viscosity on the rate of stomach emptying and intestinal transit. Increased viscosity was observed to slow gastro-intestinal transit and this provides one mechanism by which dietary fibre of the gel-forming type ray improve glucose tolerance.

Neuroendocrine neoplasms of the GI tract : the role of cytotoxic chemotherapy

Neuroendocrine neoplasms (NENs) comprise a heterogeneous group of neoplasms derived from peptide- and amine-secreting cells of the neuroendocrine system. NENs commonly arise in the GI tract but can arise in most organs of the body. NENs in different organs share many common pathologic features. Although the incidence of NENs is not high, the prevalence is not low because many patients may live relatively long periods without major symptoms from the disease. While many of these tumors lead an indolent clinical course, they constitute a therapeutic challenge when they progress, metastasize and become symptomatic. Treatment requires a multidisciplinary approach including cytotoxic chemotherapy. Almost all clinical trials investigating cytotoxic chemotherapy in NENs are small single-arm studies and guidelines are derived from expert opinion and from extrapolating results from small cell lung cancer studies. This article briefly reviews NENs before focusing on reviewing data on the role of cytotoxic chemotherapy studies in NENs.

Stomach temperature records reveal nursing behaviour and transition to solid food consumption in an unweaned mammal, the harbour seal pup (Phoca vitulina)

Knowledge of milk transfer from mother to offspring and early solid food ingestions in mammals allows for a greater understanding of the factors affecting transition to nutritional independence and pre-weaning growth and survival. Yet studies monitoring suckling behaviour have often relied on visual observations, which might not accurately represent milk intake. We assessed the use of stomach temperature telemetry to monitor suckling and foraging behaviour in free-ranging harbour seal (Phoca vitulina) pups during lactation. Stomach temperature declines were analysed using principal component and cluster analyses, as well as trials using simulated stomachs resulting in a precise classification of stomach temperature drops into milk, seawater and solid food ingestions. Seawater and solid food ingestions represented on average 15.361.6% [0-40.0%] and 0.760.2% [0-13.0%], respectively, of individual ingestions. Overall, 63.7% of milk ingestions occurred while the pups were in the water, of which 13.9% were preceded by seawater ingestion. The average time between subsequent ingestions was significantly less for seawater than for milk ingestions. These results suggest that seawater ingestion might represent collateral ingestion during aquatic suckling attempts. Alternatively, as solid food ingestions (n = 19) were observed among 7 pups, seawater ingestion could result from missed prey capture attempts. This study shows that some harbour seals start ingesting prey while still being nursed, indicating that weaning occurs more gradually than previously thought in this species. Stomach temperature telemetry represents a promising method to study suckling behaviour in wild mammals and transition to nutritional independence in various endotherm species.

Prevalência da expressão imunoistoquímica da proteína p21 em adenocarcinoma do esôfago

INTRODUÇÃO: No mundo ocidental, a prevalência de adenocarcinoma da junção esofagogástrica vem crescendo nas últimas décadas. Atualmente, é aceito que o adenocarcinoma do esôfago se desenvolve de uma lesão pré-maligna: esôfago de Barrett. Este carcinoma é de difícil diagnóstico nos seus estágios iniciais, o que resulta em uma mortalidade significativa. O estudo da biologia molecular tem demonstrado que grande parte dos tumores malignos tem origem na interação entre o componente hereditário e influências externas, que em indivíduos predispostos podem ocasionar alterações genéticas que influenciem o controle da diferenciação e crescimento celular. O p21 (WAF1/CIP1) tem um papel fundamental na regulação do ciclo celular, e sua expressão imunoistoquímica tem sido estudada em diversos tumores, mostrando influência no prognóstico de várias neoplasias. OBJETIVO: Verificar a prevalência da expressão da proteína p21 em pacientes com adenocarcinoma de esôfago diagnosticados nos últimos cinco anos no Grupo de Cirurgia de Esôfago e Estômago do Hospital de Clínicas de Porto Alegre (GCEE/HCPA). METODOLOGIA: A população em estudo foi constituída de 42 pacientes com adenocarcinoma de esôfago diagnosticados no GCEE/HCPA entre janeiro de 1998 e dezembro de 2002. A expressão da proteína p21 foi realizada por meio de imunoistoquímica, com anticorpo primário, p21, clone SX118, código M7202 da DAKO, e avaliada de acordo com o Sistema de Escore de Imunorreatividade (Immunoreactive scoring system – IRS). RESULTADOS: Foram estudados 42 pacientes. 83,3% eram do sexo masculino, com idade superior a 40 anos. Destes, 56,2% foram submetidos a procedimentos cirúrgicos com intenção curativa: Gastrectomia total e Esofagogastrectomia transiatal. Os demais foram submetidos à cirurgia paliativa ou não sofreram tratamento cirúrgico. Apenas cinco pacientes receberam tratamento adjuvante com quimioterapia e radioterapia, isoladas ou combinadas. Quanto ao estadiamento, 78,6% dos pacientes apresentavam doença avançada, estádios III e IV. Apenas 9 apresentaram positividade para o p21, quando considerado o Sistema de Escore de Imunorreatividade (em que p21+ é ³ 3). CONCLUSÃO: A proteína p21 esteve expressa em 9 dos 42 pacientes (21,4%) com adenocarcinoma de esôfago diagnosticados nos últimos cinco anos no Grupo de Cirurgia de Esôfago e Estômago do Hospital de Clínicas de Porto Alegre. Nessa casuística, o acúmulo de p21 não se mostrou essencial no processo de carcinogênese do adenocarcinoma esofágico.

Total gastrectomy with substitution of stomach by jejunal pouch with and without duodenal passage. Study in rats

A comparison was done between the F. Paulino jejunal pouch (FP) and a jejunal pouch (JP) as esophagusduodenum interpositional graft, for replacing the stomach after total gastrectomy. It was investigated the effect of the two procedures on esophagus histology, nutritional state and serum gastrin in rats. Methods: Male Wistar rats weighing 282±17g were randomly submitted to sham operation (S), FP and JP after total gastrectomy. After eight weeks the rats were killed with overdose of anesthetic and tissue was taken from the distal esophagus for histology. Serum levels of total proteins, albumin, iron, transferring, folate, cobalamine, calcium, as well as serum gastrin were determined. Survival was considered. Results: Fourty six rats were operated and thirty survived for eight weeks. Five (33.3%) died after FP and 11 (52.3%) after JP (p<0.05). Postoperative esophagitis occurred in 6 JP rats. At 8th week, no difference was observed on body weight when compared FP and JP rats (p>0.05). The JP rats had a significant decrease in serum albumin, glucose, transferrin, iron, folate and calcium, compared to sham (p<0.05). Serum gastrin, iron and calcium were significantly higher in JP rats than in FP rats (p<0.05). In FP rats, transferrin and cobalamine showed significant decrease comparing the preoperative with 8th week levels (p<0.05). Conclusion: F. Paulino pouch in rats had lower mortality than JP, and esophagitis was not detected in it. JP rats had serum gastrin, iron and calcium unaffected, possibly because of preservation of duodenal passage

Stomach fullness modulates prey size choice in the frillfin goby, Bathygobius soporator

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Morphology of glandular stomach (Ventriculus glandularis) and muscular stomach (Ventriculus muscularis) of the partrigde Rhynchotus rufescens

Vinte perdizes Rhynchotus rufescens adultas foram utilizadas para estudo morfológico do proventrículo e ventrículo gástricos da perdiz Rhynchotus rufescens. Os materiais foram coletados e os comprimentos do proventrículo e do ventrículo gástricos foram avaliados. Para o estudo histológico, fragmentos dos estômagos foram corados pelas técnicas de ácido periódico de Schiff (PAS) e tricromo de Masson. O proventrículo gástrico é alongado, com formato fusiforme direcionado no sentido craniocaudalmente e para a esquerda, e apresenta um comprimento médio 3,20cm nas fêmeas e 3,65cm nos machos. Histologicamente, o proventrículo gástrico é composto por vários lobos e glândulas. A mucosa é formada por epitélio cúbico, sendo bastante pregueada. O ventrículo gástrico tem o formato de uma lente biconvexa, com comprimento médio de 4,30cm nas fêmeas e 4,35cm nos machos. A mucosa é formada por pregas revestidas por células cilíndricas e pelo muco formador da cutícula. Há criptas na base das pregas. em seguida, há uma lâmina própria e uma espessa camada muscular lisa, que se encontra direcionada de acordo com o formato do ventrículo gástrico. A serosa é constituída por uma densa porção de tecido conjuntivo, entremeado por algumas células musculares lisas.

Morphoquantitative aspects of nitrergic myoenteric neurons from the stomach of diabetic rats supplemented with acetyl-L-carnitine

The NADPH-diaphorase (NADPH-d) positive myoenteric neurons from the body of the stomach of rats with streptozotocin-induced diabetes with or without supplementation with acetyl-L-carnitine (ALC) were evaluated. At the age of 105 days the animals were divided into four groups: normoglycaemic (C), normoglycaemic supplemented with ALC (CC), diabetic (D) and diabetic supplemented with ALC (DC). The supplementation with ALC (200 mg/kg body weight/day) to groups CC and DC was made during 105 days. After this period the animals were killed and the stomach removed and subjected to the histochemical technique of NADPH-d for the staining of the neurons of the myoenteric plexus. The area of 500 neurons of each group was investigated, as well as the neuronal density in an area of 23.84 mm(2) in each stomach. ALC promoted reduction (P < 0.05) of fasting glycaemia, water ingestion and areas of the profiles of the cell bodies of the NADPH-d neurons in the diabetic animals. The density of these neurons was not statistically different in the groups studied. It is suggested, therefore, a moderate neuroprotective effect of ALC, because the diminishment of the areas of the neuronal profiles in the supplemented diabetic animals, although being statistically significant relative to the non-supplemented diabetics, was not sufficient to equal the values from the non-diabetic controls.

Quantitative study of the myenteric plexus of the stomach of rats with streptozotocin-induced diabetes

A proposta deste trabalho foi estudar as alterações morfológicas e quantitativas dos neurônios do plexo mientérico do estômago de ratos com diabetes induzido por estreptozootocina e estabelecer uma comparação com animais não diabéticos. Amostras do corpo do estômago foram submetidas a preparados de membrana corados pelo método da NADH-diaforase e a cortes histológicos corados por hematoxilina-eosina. Observou-se que o diabetes provoca significante redução no número de neurônios.

Magnetic images of the disintegration process of tablets in the human stomach by ac biosusceptometry

Oral administration of solid dosage forms is usually preferred in drug therapy. Conventional imaging methods are essential tools to investigate the in vivo performance of these formulations. The non-invasive technique of ac biosusceptometry has been introduced as an alternative in studies focusing on gastrointestinal motility and, more recently, to evaluate the behaviour of magnetic tablets in vivo. The aim of this work was to employ a multisensor ac biosusceptometer system to obtain magnetic images of disintegration of tablets in vitro and in the human stomach. The results showed that the transition between the magnetic marker and the magnetic tracer characterized the onset of disintegration (t(50)) and occurred in a short time interval (1.1 +/- 0.4 min). The multisensor ac biosusceptometer was reliable to monitor and analyse the in vivo performance of magnetic tablets showing accuracy to quantify disintegration through the magnetic images and to characterize the profile of this process.

Infiltrating CD8(+) T lymphocytes, natural killer cells, and expression of IL-10 and TGF-beta 1 in chemically induced neoplasms in male Wistar rats

The present study aimed to estimate the number of CD8(+) T and natural killer (NK) infiltrating cells and the expression of interleukin-10 (IL-10) and transforming growth factor beta 1 (TGF-beta1) in chemically induced neoplasms in an initiation-promotion bioassay for carcinogenesis. Male Wistar rats were treated with N-nitrosodiethylamine, N-methyl-N-nitrosourea, N-butyl-N-(4-hydroxybutyl) nitrosamine, dihydroxy-di-N-propylnitrosamine, and 1,2-dimethylhydrazine for 4 weeks. Two groups were subsequently exposed through diet to phenobarbital (0.05%) or 2-acetylaminofluorene (0.01%) for 25 weeks. An untreated group was used as a control. Immune cells and cytokines were immunohistochemically evaluated in neoplasms and in surrounding normal tissues at the liver, kidneys, lung, and small and large intestines. When compared to the respective normal tissues, an increased number of NK cells was verified infiltrating the colon, lung, and kidney neoplasms, while the number of CD8+ T cells decreased in the intestine and lung neoplasms. Expression of IL-10 was found mainly in kidney tumors. TGF-beta1 was expressed mainly in the liver and kidneys tumors. The results indicate that the differential occurrence of immune cells between neoplastic and normal tissues could be dependent upon tumor microenvironment.