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Aerobic bacterial microbiota in stomoxys calcitrans: preliminary studies in Brazil

Castro,Bruno G. de; Souza,Miliane M.S. de; Bittencourt,Avelino J.
Fonte: Colégio Brasileiro de Parasitologia Veterinária Publicador: Colégio Brasileiro de Parasitologia Veterinária
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/12/2007 EN
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46.54%
The stable fly, Stomoxys calcitrans, has a great importance in medical and veterinary health due to its feeding and reproductive habits, which can disseminate some pathogenic agents among hosts even at long distances. This study aimed to describe, for the first time in Brazil, the bacterial microbiota in segments of the stable fly. Bacterial species were isolated from three different segments (cuticle, mouth parts and abdominal alimentary tract) of the stable fly. Twenty dairy farms were visited in four municipalities: Barra Mansa, Quatis, Resende and Rio Claro in the State of Rio de Janeiro in order to collect 20 flies in each site. Dissection of the flies and procedures of isolation and identification of bacterial species were performed. A total of 161 colonies of 33 distinct species were isolated, such as Escherichia coli, Staphylococcus aureus, and S. intermedius. Stomoxys calcitrans may harbor bacterial agents on their cuticle, mouth parts and abdominal alimentary tract and these bacteria may be pathogenic to their hosts.

Kinetics of Colonization of Adult Queensland Fruit Flies (Bactrocera tryoni) by Dinitrogen-Fixing Alimentary Tract Bacteria

Murphy, Kathleen M.; Teakle, David S.; MacRae, Ian C.
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /07/1994 EN
Relevância na Pesquisa
46.61%
The average total population of bacteria remained constant in the alimentary tracts of adult laboratory-raised Queensland fruit flies (Bactrocera tryoni) although the insects had ingested large numbers of live bacteria as part of their diet. The mean number of bacteria (about 13 million) present in the gut of the insects from 12 to 55 days after emergence was not significantly modified when, at 5 days after emergence, the flies were fed antibiotic-resistant bacteria belonging to two species commonly isolated from the gut of field-collected B. tryoni. Flies were fed one marked dinitrogen-fixing strain each of either Klebsiella oxytoca or Enterobacter cloacae, and the gastrointestinal tracts of fed flies were shown to be colonized within 7 days by antibiotic-resistant isolates of K. oxytoca but not E. cloacae. The composition of the microbial population also appeared to be stable in that the distribution and frequency of bacterial taxa among individual flies exhibited similar patterns whether or not the flies had been bacteria fed. Isolates of either E. cloacae or K. oxytoca, constituting 70% of the total numbers, were usually dominant, with oxidative species including pseudomonads forming the balance of the population. Antibiotic-resistant bacteria could be spread from one cage of flies to the adjacent surfaces of a second cage within a few days and had reached a control group several meters distant by 3 weeks. Restriction of marked bacteria to the population of one in five flies sampled from the control group over the next 30 days suggested that the bacterial population in the gut of the insect was susceptible to alteration in the first week after emergence but that thereafter it entered a steady state and was less likely to be perturbed by the introduction of newly encountered strains. All populations sampled...

Cholesterol crystal embolisation to the alimentary tract.

Moolenaar, W; Lamers, C B
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /02/1996 EN
Relevância na Pesquisa
46.54%
The features of cholesterol crystal embolisation (CCE) to the alimentary tract were studied by retrospective analysis of the clinical and pathological data of 96 patients (70 men, 26 women, mean age 73.8 (58-95) years) with this diagnosis in the Dutch national pathology information system (Pathologisch Anatomisch Landelijk Geautomatiseerd Archief (PALGA)) from 1973-92. In the 96 patients, 130 CCE sites were found throughout the alimentary tract, mostly in the colon (42.3%). Most patients had a history of atherosclerotic disease and presented with abdominal pain, diarrhoea, or gastrointestinal bleeding, sometimes after surgical or radiological vascular procedures. A number were taking oral anticoagulant treatment. The diagnosis of CCE had been considered before the histological diagnosis in only 11 patients. In the remaining cases, ischaemic colitis, tumour, and inflammatory bowel disease were suggested in the differential diagnosis. A premortem diagnosis of CCE was made in 70.8% of the cases. In 24 of the 35 necropsy examinations, CCE seemed to be directly or indirectly related to the cause of death. It is concluded that in this unselected, homogenous group of patients, CCE sites were most frequently found in the colon. They generally presented with abdominal pain...

Comparative morphology of the alimentary tract and its glandular derivatives of captive bustards

BAILEY, T. A. ; MENSAH-BROWN, E. P. ; SAMOUR, J. H. ; NALDO, J. ; LAWRENCE, P. ; GARNER, A.
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /10/1997 EN
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46.74%
This study describes the gross anatomy of the alimentary tract of Houbara Bustards (Chlamydotis undulata macqueenii), Kori Bustards (Ardeotis kori), Rufous-crested Bustards (Eupodotis ruficrista) and White-bellied Bustards (Eupodotis senegalensis) maintained in captivity by the National Avian Research Center in the United Arab Emirates. The morphology of the alimentary tract and the proportions of each region were similar in all 4 species. The length of the oesophagus, combined proventriculus and ventriculus, small intestine, and large intestine formed 24.2–28.4%, 7.3–9.7%, 40.5–55.1% and 9.1–14.7% of the total alimentary tract length respectively. Neither crop nor oesophageal enlargement was observed in the birds examined in this study, although male Kori Bustards possessed a saccus oralis in the oropharyngeal cavity. Oesophagi, proventriculi, ventriculi, caeca and large intestine were well developed in all species. The small intestine was shorter than that of other avian herbivores and granivores when compared on a bodyweight basis. The well differentiated stomachs and well developed caeca of the bustards examined in this study are characteristic of omnivores. Analysis of the mean lengths of the alimentary tract components and weight of the liver and pancreas showed sexual dimorphism in cases where male and female data were available for direct comparison.

Environmental factors and the development of disease and injury in the alimentary tract.

Schedl, H P
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /10/1977 EN
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46.91%
This review examines interactions between the alimentary tract and environmental agents. In these intera"ctions the alimentary tract is considered as an integrated organ system extending from mouth to anus. The alimentary tract shares with the skin and its appendages and the respiratory system the distinction of being a portal of entry into the human body for environmental agents as well as a target for their action. Food and water-borne environmental agents enter the body via the alimentary tract. By injurying the alimentary tract environmental agents after their portal of entry and thereby modulate their effects on the organism. Such modulation may enhance or depress effects of these agents. Interactions between environmental factors and the alimentary tract depend on (1) factors related to the alimentary tract that are determined by anatomic, physiologic, and biochemical considerations; (2) factors related to the environmental agents; and (3) individually determined factors. The role of these factors in development of disease and injury is considered. Environmental diseases of the alimentary tract and environmental agents acting on the gut are discussed and recommendations are made for future research.

Enhancement by bracken of induction of tumours of the upper alimentary tract by N-propyl-N-nitrosourethan.

Hirono, I.; Hosaka, S.; Kuhara, K.
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /09/1982 EN
Relevância na Pesquisa
46.54%
The effect of bracken on the induction of tumours of the upper alimentary tract by N-propyl-N-nitrosourethan (PNU) was studied in 7-week-old ACI rats. Group I received a solution of 400 pts/10(6) of PNU in their drinking water for 6 weeks; Groups II and III were given PNU as in Group I, and then from 1 week later were fed on diets containing 5 and 30% bracken, respectively, for 33 weeks; Groups IV and V were fed on diets containing 5 and 30% bracken, respectively, for 33 weeks, from 14 weeks after birth. A control group was given basal diet and water only. The experiment was terminated after 40 weeks. The induction of tumours of the upper alimentary tract by PNU was enhanced by bracken diet; i.e. the incidence of pharyngeal tumours in male rats was significantly higher (P less than 0.025) in Group II (10/13) than in Group I (3/13). The incidence and multiplicity of oesophageal tumours in female rats were also higher in Group III than in Group I (P less than 0.025 for incidence; P less than 0.05 for multiplicity). Histologically, the oesophageal tumours in female rats in Groups II and III were not only papillomas but also squamous-cell carcinomas, whereas those in females of Group I were all papillomas. Furthermore, the incidence of tumours of the forestomach in female rats was also higher (P less than 0.05) in Group II (11/13) than in Group I (4/12).

Further studies on the inhibition of colonization of the chicken alimentary tract with Salmonella typhimurium by pre-colonization with an avirulent mutant.

Berchieri, A.; Barrow, P. A.
Fonte: Cambridge University Press Publicador: Cambridge University Press
Tipo: Artigo de Revista Científica
Publicado em /06/1990 EN
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46.54%
Oral administration to newly hatched chickens or to chicks up to 5 days of age with an avirulent, rough, spectinomycin-resistant mutant of Salmonella typhimurium strain F98 inhibited the colonization of a nalidixic acid-resistant mutant of the same strain administered by the same route 1 day later. The second strain passed rapidly through the alimentary tract and persisted in the caeca of only a few chickens. Resistance to colonization did not develop until 24 h after inoculation of the first strain but was still evident if the second strain was inoculated up to 7 days later. Resistance occurred in 5 different breeds of chicken and in chickens reared on 5 different diets. Protection was evident against a very high challenge dose and could be produced by the introduction of small numbers of the first strain. Pre-colonization of chicks with the first strain of F98 reduced faecal excretion of the second strain over many weeks, whether chickens were challenged directly or by contact with other infected chickens. The rough strain F98 produced protection against only a few S. typhimurium strains and not against other serotypes. However, strains of S. infantis and S. heidelberg, chosen because they colonized the chicken alimentary tract better than did F98...

Alimentary Tract Imaging

Gibney, Robert G.; Nichols, David M.
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /05/1986 EN
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46.54%
Plain abdominal radiographs and barium studies are no longer the only available radiological methods for investigating alimentary tract disease. These basic procedures still retain their importance because of their cheapness, wide availability, and ease of performance. The newer modalities such as ultrasound, nuclear medicine, and computed tomography, however, have had a dramatic impact on the way in which common alimentary tract problems are routinely investigated in 1986. This presentation offers guidance in the investigation of acute abdomen, abdominal mass, peptic ulcer disease, right upper-quadrant pain, jaundice, altered bowel habit, and suspected pancreatic abnormality.

Tumours of the upper alimentary tract

Head, K. W.
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em //1976 EN
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46.54%
Tumours of the oropharynx of domestic animals are common in most parts of the world, but squamous cell carcinoma of the upper alimentary tract shows differences in prevalence in different geographical areas and occurs at different sites in the various species. Oral tumours of the melanogenic system are more common in dogs than in man. The following main histological categories, which broadly correspond to those used in the classification of tumours of man, are described: papilloma; squamous cell carcinoma; salivary gland tumours; malignant melanoma; tumours of soft (mesenchymal) tissues; tumours of the facial bones; tumours of haematopoietic and related tissues; and odontogenic tumours and jaw cysts. Papilloma, squamous cell carcinoma, malignant melanoma, fibroma, and fibrosarcoma account for about 80% of the tumours that occur in the upper alimentary tract of domestic animals.

Quality of life after surgery of the alimentary tract

Scarpa, Marco
Fonte: Baishideng Publishing Group Co., Limited Publicador: Baishideng Publishing Group Co., Limited
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
46.54%
In recent decades, patient-reported outcomes have become important in clinical medicine. Nowadays, health-related quality of life (HRQOL) is considered a primary outcome in many clinical trials, and it is often the major criterion for judging treatment success. At the beginning of the 21st century, morbidity and mortality rates after surgery of the alimentary tract have dropped dramatically and they can no longer be considered the only outcome measures to determine the success of a surgical procedure. QOL can yield a definitely more patient-orientated measure of outcome that provides us with a more formal measure of the patient’s judgment and desires, which can influence treatment decisions. Nevertheless, despite a very large number of published papers on HRQOL, there is some skepticism on the value of HRQOL and other patient-related outcomes. Therefore, this topic highlight aims to assess how QOL after surgery of the alimentary tract is covered in the medical literature. Different reviews have analyzed the topic according to different points of view: benign and malignant disease; curative and palliative treatment; open and minimally invasive surgical approach; traditional and newly introduced surgical procedures. This topic highlight does not aim to cover all the possible diseases or different surgical procedures...

FMRFamide-Like Immunoreactivity in the Central Nervous System and Alimentary Tract of the Non-Hematophagous Blow Fly, Phormia regina, and the Hematophagous Horse Fly, Tabanus nigrovittatus

Haselton, Aaron T; Yin, Chih-Ming; Stoffolano, John G
Fonte: University of Wisconsin Library Publicador: University of Wisconsin Library
Tipo: Artigo de Revista Científica
Publicado em 27/10/2008 EN
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46.61%
FMRFamide-related peptides (FaRPs) are a diverse and physiologically important class of neuropepeptides in the metazoa. In insects, FaRPs function as brain-gut neuropeptides and have been immunolocalized throughout the nervous system and alimentary tract where they have been shown to affect feeding behavior. The occurrence of FMRFamide-like immunoreactivity (FLI) was examined in the central nervous system and alimentary tract of non-hematophagous blow fly, Phormia regina Meigen (Diptera: Calliphoridae), and the hematophagous horse fly, Tabanus nigrovittatus Macquart (Diptera:Tabanidae). Although the central nervous system and alimentary anatomy differ between these two dipteran species, many aspects of FLI remain similar. FLI was observed throughout the central and stomatogastric nervous systems, foregut, and midgut in both flies. In the central nervous system, cells and processes with FLI occurred in the brain, subesophageal ganglion, and ventral nerve cord. FLI was associated with neurohemal areas of the brain and ventral nerve cord. A neurohemal plexus of fibers with FLI was present on the dorsal region of the thoracic central nervous system in both species. In the gut, processes with FLI innervated the crop duct, crop and anterior midgut. Endocrine cells with FLI were present in the posterior midgut. The distribution of FLI in these two flies...

Microbial Ecology of the Hive and Pollination Landscape: Bacterial Associates from Floral Nectar, the Alimentary Tract and Stored Food of Honey Bees (Apis mellifera)

Anderson, Kirk E.; Sheehan, Timothy H.; Mott, Brendon M.; Maes, Patrick; Snyder, Lucy; Schwan, Melissa R.; Walton, Alexander; Jones, Beryl M.; Corby-Harris, Vanessa
Fonte: Public Library of Science Publicador: Public Library of Science
Tipo: Artigo de Revista Científica
Publicado em 17/12/2013 EN
Relevância na Pesquisa
46.54%
Nearly all eukaryotes are host to beneficial or benign bacteria in their gut lumen, either vertically inherited, or acquired from the environment. While bacteria core to the honey bee gut are becoming evident, the influence of the hive and pollination environment on honey bee microbial health is largely unexplored. Here we compare bacteria from floral nectar in the immediate pollination environment, different segments of the honey bee (Apis mellifera) alimentary tract, and food stored in the hive (honey and packed pollen or “beebread”). We used cultivation and sequencing to explore bacterial communities in all sample types, coupled with culture-independent analysis of beebread. We compare our results from the alimentary tract with both culture-dependent and culture-independent analyses from previous studies. Culturing the foregut (crop), midgut and hindgut with standard media produced many identical or highly similar 16S rDNA sequences found with 16S rDNA clone libraries and next generation sequencing of 16S rDNA amplicons. Despite extensive culturing with identical media, our results do not support the core crop bacterial community hypothesized by recent studies. We cultured a wide variety of bacterial strains from 6 of 7 phylogenetic groups considered core to the honey bee hindgut. Our results reveal that many bacteria prevalent in beebread and the crop are also found in floral nectar...

Alimentary tract duplications in newborns and children: Diagnostic aspects and the role of laparoscopic treatment

Patiño Mayer, Jan; Bettolli, Marcos
Fonte: Baishideng Publishing Group Inc Publicador: Baishideng Publishing Group Inc
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
46.66%
Alimentary tract duplications are rare congenital lesions normally diagnosed in newborns and children that can occur anywhere from the mouth to the anus and have a reported incidence of approximately 1 in 4500 life births. Symptoms and clinical presentation vary greatly. The presentation varies according to age and location. The treatment finally is surgical; total resection when possible should be the aim of the intervention. In pediatric surgery minimally invasive surgical procedures became more and more important over the last decades. In consequence the operative procedure on alimentary tract duplications changed in this manner. We review on case reports and clinical reports on minimally invasive surgery in the treatment of alimentary tract duplications, determine the importance of minimally invasive techniques in the treatment of this rare entity and rule out that further studies in the field should be performed.

Alimentary tract mucositis in cancer patients: impact of terminology and assessment on research and clinical practice

Peterson, D.; Keefe, D.; Hutchins, R.; Schubert, M.
Fonte: Springer-Verlag Publicador: Springer-Verlag
Tipo: Artigo de Revista Científica
Publicado em //2006 EN
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46.54%
Background and significance The field of terminology and assessment of oral and gastrointestinal mucosal injury caused by high-dose cancer therapies in cancer patients has undergone important evolution in recent years. The advances are important for several clinical and research reasons. These reasons include improved patient management and design and conduct of clinical trials based on molecularly targeted therapies. For several decades leading up to the 1980s, terminology was characterized by varying use of “mucositis” and “stomatitis” to describe oral mucosal inflammatory changes and ulceration caused by cancer treatments. In addition, oral mucositis was viewed principally as an epithelial event and one that likely did not intersect with causative mechanisms associated with gastrointestinal mucositis. The term “stomatitis” was directed to oral toxicities and seemed to isolate these conditions from parallel events occurring throughout the alimentary tract and potentially other tissues as well. These perspectives and varying use of these terms resulted in several dilemmas, including (1) difficulty in accurately reporting incidence and severity of oral mucositis and, (2) an underappreciation of potential significance of alimentary tract mucosal toxicity relative to overall course of therapy...

Radiation therapy-induced mucositis: Relationships between fractionated radiation, NF-kappa B, COX-1, and COX-2

Yeoh, A.; Gibson, R.; Yeoh, E.; Bowen, J.; Stringer, A.; Giam, K.; Logan, R.; Keefe, D.
Fonte: W B Saunders Co Ltd Publicador: W B Saunders Co Ltd
Tipo: Artigo de Revista Científica
Publicado em //2006 EN
Relevância na Pesquisa
46.54%
Radiation therapy is one of the three major treatment modalities used in eradicating malignant tumours. When ionising radiation is used to treat abdominal tumours, severe side effects largely due to mucosal damage in the alimentary tract are common, particularly when it is combined with chemotherapy. Radiation-induced mucositis may not only limit the therapeutic doses of combined treatment but also adversely affect the quality of life of the patient. Treatment strategies to treat and prevent radiation-induced mucositis have been reviewed and published in the Clinical Practice Guidelines, 2004. However evidence supporting an effective treatment approach is tenuous, probably because the mechanistic evolution of radiation-induced mucositis is poorly understood. Several animal models have been used to examine the various effects of radiation but no single animal model has been able to effectively capture the effects of radiation on the alimentary tract at the molecular level before symptoms begin. This review will outline the events which occur following radiation exposure; from chromosomal aberrations in the mucosal cells leading to apoptotic and mitotic death, to the evolution of mucositis involving changes in gene activations and signaling. A better understanding of the mechanisms of radiation therapy-induced mucositis is necessary as it will allow for future pharmaceutical interventions to alleviate if not eliminate the debilitating side effects.; http://www.elsevier.com/wps/find/journaldescription.cws_home/623022/description#description; Ann Yeoh...

Alimentary tract mucositis: NF-kB and pro-inflammatory cytokines in the tissues and serum following chemotherapy.

Logan, Richard Martin
Fonte: Universidade de Adelaide Publicador: Universidade de Adelaide
Tipo: Tese de Doutorado
Publicado em //2008
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56.71%
Mucositis refers to the widespread damage of mucosal surfaces throughout the length of the alimentary tract (AT) that can occur during cancer treatment. Its development is an important clinical problem that complicates and limits treatment options as well as adversely affecting the quality of life and treatment outcomes for patients. Recent studies directed at determining the pathobiology of mucositis have indicated increasing evidence for the role of transcription factors, such as nuclear factor-κB (NF-κB), and certain pro-inflammatory cytokines, for example tumour necrosis factor (TNF), interleukin-1β (IL-1β) and interleukin- 6 (IL-6), in its development. This thesis developed from an initial clinical investigation in which the expression of NF-κB and COX-2 in oral mucosa was investigated in patients undergoing chemotherapy. Increased levels of NF-κB were demonstrated in the buccal mucosa following chemotherapy. It is well established that mucositis occurs in different sites of the AT. The aims of this research, therefore, were to compare and contrast the changes that do occur at different sites of the AT following chemotherapy in an established animal model (Dark Agouti (DA) rat). Furthermore, the studies were conducted to determine whether changes in tissue and serum levels of NF-κB and pro-inflammatory cytokines occurred following chemotherapy and...

Matrix metalloproteinases: key regulators in the pathogenesis of chemotherapy-induced mucositis?

Al-Dasooqi, N.; Gibson, R.; Bowen, J.; Keefe, D.
Fonte: Springer Publicador: Springer
Tipo: Artigo de Revista Científica
Publicado em //2009 EN
Relevância na Pesquisa
46.54%
Chemotherapy is an effective anticancer treatment; however, it induces mucositis in a wide range of patients. Mucositis is the term used to describe the damage caused by radiation and chemotherapy to mucous membranes of the alimentary tract. This damage causes pain and ulceration, vomiting, bloating and diarrhoea, depending on the area of the alimentary tract affected. Although treatment is available for a small subset of patients suffering from mucositis, the majority rely on pain relief as their only treatment option. Much progress has been made in recent years into understanding the pathobiology underlying the development of mucositis. It is well established that chemotherapy causes prominent small intestinal and colonic damage as a result of up-regulation of stress response genes and pro-inflammatory cytokines. However, better understanding of the mediators of this damage is still required in order to target appropriate treatment strategies. Possible mediators of mucositis which have not been well researched are the matrix metalloproteinases (MMPs). MMPs have been shown to function in several of the pathways which are known to be up-regulated in mucositis and contribute to tissue injury and inflammation in many pathological conditions. This prompts the consideration of MMPs as possibly being key mediators in mucositis development.; Noor Al-Dasooqi...

Matrix metalloproteinases are possible mediators for the development of alimentary tract mucositis in the dark agouti rat

Al-Dasooqi, N.; Gibson, R.; Bowen, J.; Logan, R.; Stringer, A.; Keefe, D.
Fonte: Blackwell Science Inc Publicador: Blackwell Science Inc
Tipo: Artigo de Revista Científica
Publicado em //2010 EN
Relevância na Pesquisa
66.54%
Alimentary tract (AT) mucositis is a serious and debilitating side-effect of cancer therapy primarily characterized by damage of the mucous membranes throughout the AT. It is well established that this damage is a result of up-regulation of stress response genes and pro-inflammatory cytokines. Matrix metalloproteinases (MMPs) have been shown to function in several of the pathways known to be up-regulated in mucositis and play a key role in tissue injury and inflammation in many gastrointestinal disorders. This study aims to characterize the expression of multiple MMPs including MMP-1, -2, -3, -9 and -12 and their inhibitors, tissue inhibitor of metalloproteinase (TIMP)-1 and -2, in a rat model of irinotecan-induced mucositis. Dark agouti rats were administered a single 200 mg/kg intraperitoneal dose of irinotecan and killed at 1, 6, 24, 48, 72, 96 and 144 h following treatment. Hematoxylin and eosin staining, immunohistochemistry and realtime polymerase chain reaction were used to assess histopathological damage and MMP expression in the jejunum and colon. Marked histopathological evidence of mucositis was observed in the jejunum and colon as early as six hours following irinotecan treatment. A significant alteration in both gene expression and tissue levels of MMPs and TIMPs was noted following irinotecan. The increase in MMP-2...

Identification and characterization of functional aquaporin water channel protein from alimentary tract of whitefly, Bemisia tabaci

Matthew, L.; Campbell, E.; Yool, A.; Fabrick, J.
Fonte: Elsevier Publicador: Elsevier
Tipo: Artigo de Revista Científica
Publicado em //2011 EN
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46.61%
Some hemipteran xylem and phloem-feeding insects have evolved specialized alimentary structures or filter chambers that rapidly transport water for excretion or osmoregulation. In the whitefly, Bemisia tabaci, mass movement of water through opposing alimentary tract tissues within the filter chamber is likely facilitated by an aquaporin protein. B. tabaci aquaporin-1 (BtAQP1) possesses characteristic aquaporin topology and conserved pore-forming residues found in water-specific aquaporins. As predicted for an integral transmembrane protein, recombinant BtAQP1 expressed in cultured insect cells localized within the plasma membrane. BtAQP1 is primarily expressed in early instar nymphs and adults, where in adults it is localized in the filter chamber and hindgut. Xenopus oocytes expressing BtAQP1 were water permeable and mercury-sensitive, both characteristics of classical water-specific aquaporins. These data support the hypothesis that BtAQP1 is a water transport protein within the specialized filter chamber of the alimentary tract and functions to translocate water across tissues for maintenance of osmotic pressure and/or excretion of excess dietary fluid.; Lolita G. Mathew, Ewan M. Campbell, Andrea J. Yool, Jeffrey A. Fabrick

Distribution of the carbonic anhydrase isoenzymes I, II, and VI in the human alimentary tract.

Parkkila, S; Parkkila, A K; Juvonen, T; Rajaniemi, H
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /05/1994 EN
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46.59%
The distribution of carbonic anhydrase isoenzymes I, II, and VI was studied in the human alimentary tract using specific antibodies to human isoenzymes in conjunction with the immunoperoxidase technique to elucidate the physiological role and possible functional interplay of carbonic anhydrases (CAs) in alimentary canal functions. From the isoenzymes studied, CA II was found to be the most widely distributed in the various epithelia throughout the alimentary canal. In addition to the acinar cells of the parotid and submandibular glands and the duodenal Brunner's glands, it was present in the mucosal epithelium of the oesophagus, stomach, duodenum, and colon. The epithelial cells of the hepatic bile ducts, gall bladder, and pancreatic ducts also contained CA II in abundance. In contrast, CA VI was present only in the serous acinar and ductal cells of the parotid and submandibular glands, and CA I in the mucosal epithelium of the colon and the A cells of the pancreatic Langerhans's islets. These results suggest that CA II as a widely distributed isoenzyme in the epithelia of the alimentary canal and CA VI as secreted into saliva, may form a mutually complementary system protecting oesophageal, gastric, and intestinal mucosa from acidity.