Histology and histopathology Vol.22, nº11 (2007)
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- PublicationOpen AccessHistological evaluation of colonic anastomotic healing, during perioperative Capecitabine administration. Experimental study in rats(Murcia : F. Hernández, 2007) Konstantinidis, H.D.; Sioga, A.C.; Economou, L.; Mpallas, K.D.; Demertzidis, C.I.; Pissanidou, T.T.Background: Neoadjuvant chemotherapy is a highly promising treatment modality for colorectal cancer. One of the basic side effects of this method is the possible impact on anastomotic healing. Capecitabine is a tumor selective pro-drug of 5-fluorouracil, indicated for the therapy of colorectal cancer. The aim of this study is to estimate the effect of perioperative Capecitabine administration on the colonic anastomotic healing process, by evaluating histopathological findings. Methods: We studied the effect of Capecitabine on hand sutured colonic anastomosis in rats. Sixty Wistar rats were randomized in two groups. In the study group (n=30) Capecitabine was given p.o. in therapeutic dose of 359 mg/kg, (2/3 of the mean toxic dose), 1 week prior the anastomosis and throughout the study. In the control group (n=30) placebo medication was administrated. Both groups were further subdivided into 3 groups, each consisting of 10 animals. Rats of each group were sacrificed on the 3rd, 7th and 14th postoperative day, in both study and control groups. Results: No negative impact on the healing process of colonic anastomosis was found. Histological findings indicated a more effective healing during the early postoperative days, with lesser necrosis effects on the anastomotic line for the study group, in comparison with the control group. The median bursting pressure was found to be significantly higher in the subdivision of the study group sacrificed on the 3rd day, in comparison to respective control subdivision. Conclusion: Perioperative administration of Capecitabine, as neoadjuvant chemotherapy, does not impair the healing of colonic anastomosis in rats.
- PublicationOpen AccessRecent development of in vivo cryotechnique to cryobiopsy for living animals(Murcia : F. Hernández, 2007) Ohno, N.; Terada, N.; Saitoh, S.; Zhou, H.; Fuji, Y.; Ohno, S.Various microscopic methods have been used to analyze the morphology and molecular distribution of cells and tissues. Using conventional procedures, however, ischemic or anoxic artifacts are inevitably caused by tissue-resection or perfusion-fixation. The in vivo cryotechnique (IVCT) was developed to overcome these problems, and was found to be useful with light microscopy for analyses of the distribution of watersoluble molecules without anoxic effects at high time resolution. But there are limitations to the application of IVCT, such as exposure of target organs of living small animals and immunoreactivity of lipid-soluble molecules owing to freeze-substitution with acetone. Recently, a new cryotechnique called “cryobiopsy” has been developed, which enables one to obtain tissue specimens of large animals including humans without ischemia or anoxia, and has almost the same technical advantages as IVCT. Both IVCT and cryobiopsy complement other live-imaging techniques, and are useful for not only the morphological observation of cells and tissues under normal conditions, but also the preservation of all components in frozen tissue specimens. Therefore, morphofunctional information in vivo would be obtained by freeze-substituion for light or electron microscopy, and also by other analytical methods, such as freezefracture replication, X-ray microanalyses, or Raman microscopy. Considering the merits of both IVCT and cryobiopsy, their application should be expanded into other microscopic fields and also from experimental animal studies to clinical medicine.
- PublicationOpen AccessGrowth hormone treatment prevents osteoporosis in uremic rats(Murcia : F. Hernández, 2007) Berger, I.; Piecha, G.; Rabkin, R.; Kaya, N.; Geldyyev, A.; Sun, D.; Chen, Y.; Koleganova, Nadezda; Gross, M.L.Introduction: Growth hormone (GH) is responsible for longitudinal bone growth. GH-receptor in the growth plate was found to be decreased in chronic renal insufficiency. A therapeutic use of GH in chronic renal insufficiency is not established. The current study aims to clarify the effects of GH treatment on bone metabolism in a uremic rat model. Methods: Sprague Dawley rats were subjected to subtotal surgical renal ablation (SNX) or sham operation. SNX rats were randomized into 4 groups: treated with different doses of GH (1.5, 4.0, or 10.0 mg/kg) or vehicle after 10 weeks of uremia and treated for 6 weeks. Bone and renal morphology was evaluated: bone density, thickness of spongiosa, osteoblast surface, osteoid volume, osteoclast quantity, and resorptive volume. Results: GH treatment resulted in a decrease of resorption area and lower number of osteoclasts. Osteoid volume, number of osteoblasts, percentage of active osteoblasts, thickness of the growth plate and mean cortical width increased. GH receptor (GHR) protein expression increased in GH treated rats. IGF-1 expression was decreased in osteoblasts and chondroblasts of SNX-V rats and increased following GH treatment. The TGF-ß expression was down regulated in SNX+V group in osteocytes and chondroblasts as compared to sham operated animals. The down regulation was prevented in treated animals irrespective of the dose given. Conclusions: Treatment with GH in uremic animals increased bone density to the levels of non-uremic controls. Thus GH seems to have a potential of preventing renal osteodystrophy.
- PublicationOpen AccessInnervation of the canine mammary gland: an immunohistochemical study(Murcia : F. Hernández, 2007) Pinho, M.S.; Gulbenkian, S.The distribution of peptidergic nerves in canine mammary tissues was studied by immunohistochemical techniques. In addition, the general and the noradrenergic innervations were demonstrated using protein gene product 9.5 and tyrosine hydroxylase immunoreactivities as markers, respectively. Tissue specimens from the caudal mammary glands were obtained from adult, nonlactating, female dogs. The overall innervation of the mammary gland tissue was sparse and primarily associated with the arterial vasculature. Nerve fibres positive for protein gene product 9.5 were rarely found in the secretory parenchyma. The nipple was not richly innervated, although it displayed a greater amount of nerve fibres than the mammary parenchyma. Nerve fibres supplying nonvascular structures of the nipple expressed immunoreactivity for the sensory neuropeptides calcitonin gene-related peptide, substance P and neuropeptide K, but not for vasoactive intestinal peptide, peptide histidine isoleucine and C-flanking peptide of neuropeptide Y. Somatostatin immunoreactivity was not detected in mammary gland tissue. Our results indicate that the innervation of the canine mammary gland is mainly affiliated with the vasculature and comprises peptidergic nerves which may be involved in the regulation of local blood flow. The presence of sensory neuropeptides in nerves supplying the mammary nipple suggest that these peptides may play a role in the afferent pathway of the milk ejection reflex.
- PublicationOpen AccessThe Src homology 2 domain tyrosine phosphatases SHP-1 and SHP-2: diversified control of cell growth, inflammation, and injury(Murcia : F. Hernández, 2007) Chong, Z.Z.; Maiese, K.Interest in the diverse biology of protein tyrosine phosphatases that are encoded by more than 100 genes in the human genome continues to grow at an accelerated pace. In particular, two cytoplasmic protein tyrosine phosphatases composed of two Src homology 2 (SH2) NH2-terminal domains and a C-terminal proteintyrosine phosphatase domain referred to as SHP-1 and SHP-2 are known to govern a host of cellular functions. SHP-1 and SHP-2 modulate progenitor cell development, cellular growth, tissue inflammation, and cellular chemotaxis, but more recently the role of SHP-1 and SHP-2 to directly control cell survival involving oxidative stress pathways has come to light. SHP-1 and SHP-2 are fundamental for the function of several growth factor and metabolic pathways yielding far reaching implications for disease pathways and disorders such as diabetes, neurodegeneration, and cancer. Although SHP-1 and SHP-2 can employ similar or parallel cellular pathways, these proteins also clearly exert opposing effects upon downstream cellular cascades that affect early and late apoptotic programs. SHP-1 and SHP-2 modulate cellular signals that involve phosphatidylinositol 3-kinase, Akt, Janus kinase 2, signal transducer and activator of transcription proteins, mitogen-activating protein kinases, extracellular signalrelated kinases, c-Jun-amino terminal kinases, and nuclear factor-kB. Our progressive understanding of the impact of SHP-1 and SHP-2 upon multiple cellular environments and organ systems should continue to facilitate the targeted development of treatments for a variety of disease entities.
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