Histology and histopathology Vol.19, nº 2 (2004)

Permanent URI for this collection

https://hdl.handle.net/10201/17756

Browse

Now showing 1 - 20 of 28

Open Access
Molecular imaging: Bridging the gap between neuroradiology and neurohistology
(Murcia : F. Hernández, 2004) Heckl, S.; Pipkorn, R.; Nägele, T.; Vogel, U.; Küker, W.; Voigt, K.
Historically, in vivo imaging methods have largely relied on imaging gross anatomy. More recently it has become possible to depict biological processes at the cellular and molecular level. These new research methods use magnetic resonance imaging (MRI), positron emission tomography (PET), near-infrared optical imaging, scintigraphy, and autoradiography in vivo and in vitro. Of primary interest is the development of methods using MRI and PET with which the progress of gene therapy in glioblastoma (herpes simplex virus–thymidine kinase) and Parkinson’s disease can be monitored and graphically displayed. The distribution of serotonin receptors in the human brain and the duration of serotonin- receptor antagonist binding can be assessed by PET. With PET, it is possible to localize neurofibrillary tangles (NFTs) and ß-amyloid senile plaques (APs) in the brains of living Alzheimer disease (AD) patients. MR tracking of transplanted oligodendrocyte progenitors is feasible for determining the extent of remyelinization in myelin-deficient rats. Stroke therapy in adult rats with subventricular zone cells can be monitored by MRI. Transgene expression (ß-galactosidase, tyrosinase, engineered transferrin receptor) can also be visualized using MRI. Macrophages can be marked with certain iron-containing contrast agents which, through accumulation at the margins of glioblastomas, ameliorate the visual demarcation in MRI. The use of near-infrared optical imaging techniques to visualize matrix-metalloproteinases and cathepsin B can improve the assessment of tumor aggressiveness and angiogenesis-inhibitory therapy. Apoptosis could be detected using near-infrared optical imaging representation of caspase 3 activity and annexin B. This review demonstrates the need for neurohistological research if further progress is to be made in the emerging but burgeoning field of molecular imaging.
Open Access
Cholinergic, nitrergic and peptidergic (Substance P- and CGRP-utilizing) innervation of the horse intestine. A histochemical and immunohistochemical study
(Murcia : F. Hernández, 2004) Domeneghini, C.; Radaelli, G.; Arrighi, S.; Bosi, G.; Dolera, M.
The small and large intestine of adult horses were histochemically and immunohistochemically investigated in order to evidence components of the intramural nervous system. The general structural organization of the intramural nervous system was examined by using Nissl-thionin staining as well as the anti-neurofilament 200 (NF200) immunoreaction, which demonstrated the presence of neurons in the submucous as well as myenteric plexuses. The additional presence of subserosal ganglia was shown in the large intestine. Acetylcholinesterase (AChEase) activity was observed in both the submucous and myenteric plexuses. Localization of acetylcholine-utilizing neurons was also evidenced by immunohistochemical reactions for choline acetyltransferase (ChAT) and vesicular acetylcholine transporter (VAChT). With both histochemistry and immunohistochemistry possible cholinergic nerve fibres were detected in the inner musculature. The two possible cholinergic co-mediators Calcitonin Gene-Related Peptide (CGRP) and Substance P (SP) have been investigated by an immunohistochemical approach. CGRP immunoreactivity was detected in roundish nerve cell bodies as well as in nerve fibres of the submucous plexus, whereas SP immunoreactivity was evidenced in nerve fibres of the tunica mucosa, in nerve cell bodies and fibres of the submucous plexus and in nerve fibres of the myenteric plexus. NADPH-diaphorase reactivity, which is linked to the synthesis and release of nitric oxide, was detected in nerve cell bodies and nerve fibres of both the submucous and myenteric plexuses as well as in a subserosal localization of the large intestine. The nitrergic components were confirmed by the anti-NOS (nitric oxide synthase) immunoreaction. Results are compared with those of other mammals and related to the complex intestinal horse physiology and pathophysiology.
Open Access
Structural pathways for macromolecular and cellular transport across the blood-brain barrier during inflammatory conditions. Review
(Murcia : F. Hernández, 2004) Lossinsky, A.S.; Shivers, R.R.
Open Access
Relationships between stem cells and cancer stem cells
(Murcia : F. Hernández, 2004) Crowe, D.L.; Parsa, B.; Sinha, U.K.
Stem cells have been shown to exist in a variety of tissues. Recent studies have characterized stem cell gene expression patterns, phenotypes, and potential therapeutic uses. One of the most important properties of stem cells is that of self renewal. This raises the possibility that some of the clinical properties of human tumors may be due to transformed stem cells. Similar signaling pathways may regulate self renewal in normal and transformed stem cells. These rare transformed stem cells may drive the process of tumorigenesis due to their potential for self renewal. There are important ramifications for clinical cancer treatment if the growth of solid tumors is at least partially dependent on a cancer stem cell population. In the cancer stem cell model, tumor recurrence may be due to the non-targeted stem cell compartment repopulating the tumor. If cancer stem cells can be prospectively identified and isolated, it should be possible to identify therapies that will selectively target these cells.
Open Access
Amplification of CDK4, MDM2, SAS and GLI genes in leiomyosarcoma, alveolar and embryonal rhabdomyosarcoma
(Murcia : F. Hernández, 2004) Ragazzini, P.; Gamberi, G.; Pazzaglia, L.; Serra, M.; Magagnoli, Giovanna; Ponticelli, F.; Ferrari, C.; Ghinelli, C.; Alberghini, M.; Bertoni, F.; Picci, P.; Benassi, M.S.
We evaluated amplification and overrepresentation of CDK4, MDM2, GLI and SAS genes of the 12q13-15 region, in a group of soft tissue sarcomas including leiomyosarcomas (LMS), alveolar rhabdomyosarcomas (ARMS) and embryonal (anaplastic and classic variants) rhabdomyosarcomas (ERMS), to ascertain genomic alterations and possible differences within histologic subtypes of rhabdomyosarcoma (RMS). Quantitative real-time PCR was performed on DNA samples from 29 LMS, 9 ARMS, 7 anaplastic ERMS and 6 classic ERMS. Alteration of one or more of the 12q13-15 genes was revealed in 13/29 LMS (45%) and 12/22 RMS (54%) including 5/9 ARMS (56%), 5/7 anaplastic ERMS (71%) and 2/6 classic ERMS (33%). The potential importance of overproduction of protein products in neoplastic development, led us also to study a possible high expression of cdk4, mdm2 and gli proteins in immunohistochemical staining experiments on paraffin-embedded tissue samples of the same cases. Among LMS and RMS most cases with CDK4, MDM2 and GLI gene alterations also showed a simultaneous high expression of the relative protein. In summary, these results indicate that amplification or overerepresentation of genes at 12q13-15 region involve both LMS and RMS. Moreover these genes alterations reveal predominantly in the alveolar and in the anaplastic variant of the embryonal subtype. These two seem to have a more similar behavior than anaplastic and classic embryonal that are classified in the same subtype.
Open Access
Bone growth, modeling and remodeling in a supernumerary metatarsal bone associated with segmental gigantism in cutis marmorata telangiectatica congenita
(Murcia : F. Hernández, 2004) Marotti, F.; Bertolani, M.F.; Palumbo, C.
Skeletal structure and processes of bone growth, modeling and remodeling were studied in a supernumerary metatarsal surgically removed from a 3- year-old boy affected by Cutis Marmorata Telangiectatica Congenita (CMTC), associated with hypertrophy of the right upper and lower limbs and postaxial hexadactylism of the homolateral hand and foot. No other anomalies were observed. The excess of periosteal growth, due to congenital anomaly, induced an abnormal development of both modeling and remodeling processes. In bone modeling, osteoblast activity on the periosteal surface was not paralleled by osteoclast resorption along the wall of the medullary canal, and this enormously increased the cortical thickness. In bone remodeling, osteoclastic resorption cavities were not refilled by secondary Haversian systems, thus inducing a severe bone loss. While the alteration of bone growth and modeling can be ascribed to the congenital disease, the unbalanced bone remodeling appears mainly to depend on mechanical disuse of the supernumerary metatarsal.
Open Access
Interaction between cell and extracellular matrix in heart disease: Multiple roles of tenascin-C in tissue remodeling
(Murcia : F. Hernández, 2004) Imanaka-Yoshida, K.; Hiroe, M.; Yoshida, T.
The heart remodels myocardial tissue in physiological and pathological response. The cellextracellular matrix (ECM) interaction provides not only structural and mechanical support but also important biological signaling during tissue remodeling. Among various ECM molecules, tenascin-C (TNC) is well known as a regulator of multiple cellular functions during embryogenesis, wound healing or cancer progression. In the heart, TNC appears in several important steps of embryonic development such as the initial differentiation of cardiomyocytes or coronary vasculo/angiogenesis, but it is not detected in a normal adult myocardium. However, TNC is found to re-express after myocardial injury and may regulate cellular behavior during tissue remodeling by modulating the attachment of cardiomyocytes to connective tissue, by enhancing migration and differentiation of myofibroblasts, and by inducing matrix metalloproteinases. TNC also interacts with other ECM molecules and may modulate progression of fibrosis. Furthermore, transient and site specific expression of TNC closely associated with myocardial injury and inflammation suggests not only its key roles during tissue remodeling but also that TNC can be a marker for myocardial disease activity.
Open Access
To NO or not to NO, where, is the question
(Murcia : F. Hernández, 2004) Govers, R.; Oess, S.
Nitric oxide (NO) is a gaseous radical with unique biological functions essential for the cardiovascular system, host defense and neurotransmission. For two decades it was thought that NO was able to diffuse freely across relatively long distances and to traverse major parts of the cell, if not multiple cell layers. However, NO has been proven to be extremely reactive: it reacts with other reactive oxygen species, heavy metals, as well as with cysteine and tyrosine residues in proteins. In accordance, it is now widely accepted that once NO is generated, it is very short-lived and diffuses only over a short distance. This urges for the local production of NO and the localization of NO synthases in the proximity of their downstream targets. This review discusses the highly organized localization of NO synthases, with the endothelial isoform (eNOS) as its main focus, since from this synthase most is known about its subcellular localization and regulation.
Open Access
A truncated isoform of the PP2A B56g regulatory subunit reduces irradiation-induced Mdm2 phosphorylation and could contribute to metastatic melanoma cell radioresistance
(Murcia : F. Hernández, 2004) Koma, Y.-i.; Ito, A.; Watabe, K.; Kimura, S. H.; Kitamura, Y.
F10, a subline of the B16 mouse melanoma cell line, is itself the parent of the more metastatic BL6 line. BL6 cells differ from F10 cells by an alteration of the gene encoding the B56g regulatory subunit of protein phosphatase 2A (PP2A), which results in mRNA encoding a truncated variant of the subunit (Dg1). Expression of Dg1 protein is detectable only when BL6 cells are transplanted into mice and then g-irradiated. Recently, B56g subunit-containing PP2A holoenzymes have shown to dephosphorylate Mdm2, a negative regulator of p53. Thus, we assessed whether the expression of Dg1 affects irradiation-induced phosphorylation of Mdm2 and radioresistance of melanoma cells by perturbing the regulation of p53. Western blot analyses revealed that irradiated COS-7 and NIH3T3 cells stably expressing Dg1 showed significantly less irradiation-induced Mdm2 phosphorylation. Mdm2 phosphorylation reduces the ability of Mdm2 to target p53 for degradation, which probably explained why p53 protein levels in NIH3T3 cells expressing Dg1 were not significantly elevated by irradiation, unlike in wild-type cells. This was also true for F10 cells transfected with Dg1 (F10Dg1) when the cells expressed Dg1 after being irradiated in vivo. p53 mRNA levels in irradiated wild-type and Dg1-expressing cells were both only slightly elevated, suggesting that Mdm2 regulates p53 levels by a post-transcriptional mechanism. p53-mediated induction of the pro-apoptotic gene encoding Bax was also significantly lower in F10Dg1 cells irradiated in vivo. Moreover, F10Dg1 and BL6 cells were less apoptotic than F10 cells when the cells were irradiated in vivo. The p53 in F10 cells appears to be as functional as that in NIH3T3 cells because irradiation-induced expression of p53-target genes was comparable in both cells. Collectively, Dg1 appears to reduce irradiation-induced Mdm2 phosphorylation, which then blocks irradiation-stimulated p53 accumulation. Defects, such as Dg1, in PP2A may thus contribute to melanoma cell radioresistance.
Open Access
Localization of sex steroid receptors in human skin
(Murcia : F. Hernández, 2004) Pelletier, G.; Ren, L.
Sex steroid hormones are involved in regulation of skin development and functions as well as in some skin pathological events. To determine the sites of action of estrogens, androgens and progestins, studies have been performed during the recent years to accurately localize receptors for each steroid hormone in human skin. Androgen receptors (AR) have been localized in most keratinocytes in epidermis. In the dermis, AR was detected in about 10% of fibroblasts. In sebaceous glands, AR was observed in both basal cells and sebocytes. In hair follicles, AR expression was restricted to dermal papillar cells. In eccrine sweat glands, only few secretory cells were observed to express AR. Estrogen receptor (ER) a was poorly expressing, being restricted to sebocytes. In contrast, ERß was found to be highly expressed in the epidermis, sebaceous glands (basal cells and sebocytes) and eccrine sweat glands. In the hair follicle, ERß is widely expressed with strong nuclear staining in dermal papilla cells, inner sheath cells, matrix cells and outer sheath cells including the buldge region. Progesterone receptors (PR) staining was found in nuclei of some keratinocytes and in nuclei of basal cells and sebocytes in sebaceous glands. PR nuclear staining was also observed in dermal papilla cells of hair follicles and in eccrine sweat glands. This information on the differential localization of sex steroid receptors in human skin should be of great help for future investigation on the specific role of each steroid on skin and its appendages.
Open Access
Delayed remodeling in the early period of fracture healing in spontaneously diabetic BB/OK rats depending on the diabetic metabolic state
(Murcia : F. Hernández, 2004) Follak, N.; Klöting, I.; Wolf, E.; Merk, H.
Several clinical series, analyzing fracture healing in patients with insulin-dependent type 1 diabetes (IDDM) demonstrated significant incidence of delayed union, non-union, and pseudarthrosis. The purpose of this study was to examine the detailed histomorphometry and histology of bone formation and remodeling during fracture healing depending on the diabetic metabolic state in spontaneously diabetic BB/O(ttawa)K(arlsburg) rats, a rat strain that represents a close homology to IDDM in man. A standardized fracture model was chosen and based on blood-glucose values at the time of surgery (mg%), postoperative blood-glucose course (mg%) and postoperative insulin requirements (IU/kg), 100 spontaneously diabetic BB/OK rats were divided into groups with well-compensated (n=50, 167±77 mg%; 244±68 mg%; 1.8±1.9 IU/kg) or poorly compensated (n=50, 380±89 mg%; 415±80 mg%; 6.0±1.0 IU/kg) metabolic state. Fifty LEW.1A rats served as the normoglycemic controls (97±15 mg%). Ten animals from each group were killed 1, 2, 3, 4 and 6 weeks after fracture and specimens were processed undecalcified for quantitative histomorphometry and for qualitative light microscopy. In terms of bone histomorphometry, within the first four weeks after fracture, severe mineralization disorders occurred exclusively in the rats with poorly compensated diabetic metabolic states with a significantly decrease of all fluorochrome-based parameters of mineralization, apposition, formation and timing of mineralization in comparison to the spontaneously diabetic rats with wellcompensated metabolic states and to the control rats. This was confirmed histologically. Early fracture healing in the spontaneously diabetic BB/OK rats is delayed exclusively in poorly compensated diabetic metabolic states, and 6 weeks after fracture, histomorphometrically significant deficits in the measured and dynamically calculated parameters remain. This study suggests that strictly controlled insulin treatment resulting in well-compensated diabetic metabolic states will ameliorate the impaired early mineralization and cell differentiation disorders of IDDM fracture healing.
Open Access
Human articular chondrocytes, synoviocytes and synovial microvessels express aquaporin water channels; upregulation of AQP1 in rheumatoid arthritis
(Murcia : F. Hernández, 2004) Trujillo, E.; Gonzalez, T.; Marín, R.; Martín-Vasallo, P.; Marples, D.; Mobasheri, A.
Recent studies have shown that aquaporin water channels are expressed in human Meckel’s cartilage. The aim of the present investigation was to determine if human articular chondrocytes and synoviocytes express aquaporin 1 (AQP1) water channels and to establish if there are any alterations in AQP1 expression in osteoarticular disorders such as osteoarthritis (OA) and rheumatoid arthritis (RA). Immunohistochemistry was employed semiquantitatively to compare the expression of AQP1 in human chondrocytes derived from normal, OA and RA joints. PCR, cloning and sequencing confirmed the presence of AQP1 transcripts in chondrocytes. Normal human tissue microarrays including samples of kidney, choroid plexus and pancreas were used as positive controls for AQP1 expression. In most tissues AQP1 was expressed along endothelial barriers. In the kidney AQP1 was present in the glomerular capillary endothelium, proximal tubule and descending thin limbs. AQP1 was also localized to pancreatic ducts and acini and the apical membrane domain of the choroid plexus. Immunohistochemistry showed that AQP1 is expressed in synovial micro-vessels, synoviocytes and predominantly in chondrocytes located in the deep zone of articular cartilage. Image analysis of normal, OA and RA cartilage suggested that AQP1 may be upregulated in RA. This is the first report of AQP1 mRNA and protein expression in articular chondrocytes and synoviocytes. These findings suggest a potential role for AQP1 and possibly other members of the AQP gene family in the movement of extracellular matrix and metabolic water across the membranes of chondrocytes and synoviocytes for the purposes of chondrocyte volume regulation and synovial homeostasis.
Open Access
Involution of seminiferous tubules in aged hamsters: an ultrastructural, immunohistochemical and quantitative morphological study
(Murcia : F. Hernández, 2004) Morales, E.; Horn, R.; Pastor, L.M.; Santamaria, L.; Pallarés, J.; Zuasti, A.; Ferrer, C.; Canteras, M.
In this study, we examined the age-related changes on morphometric parameters and ultrastructure of seminiferous tubules, and on the expression of extracellular matrix proteins in lamina propria of Syrian hamsters. A significant decrease in the percentage of normal tubules and an increase in the percentage of hypospermatogenic and arrested maturation tubules was observed with aging. Aged animals showed a decrease in tubular diameter, tubular lumen, seminiferous epithelium volume and total tubular volume. However, the total length of seminiferous tubules was significantly increased with aging. The most important ultrastructural changes with aging were the thickening of the lamina propria, the presence of diverse abnormalities in the spermiogenesis process, degeneration of germ cells, and vacuolization and flattening of Sertoli cells showing abundant lipofucsin droplets and residual bodies. Laminin immunoreactivity was found along the lamina propria of seminiferous tubules both in young and aged animals. Fibronectin immunoreactivity was found along the lamina propria and blood vessels. Both laminin and fibronectin total volume of immunostaining per testis was increased in aged hamsters. In conclusion, the agerelated changes in seminiferous tubules of hamster include: a decrease in tubular width and an increase in tubular length; widening of the lamina propria caused by a more extensive connective matrix between the peritubular cells and the basal membrane; and a strong disarrangement of the seminiferous epithelium, including germ cell degeneration and important alterations in both spermiogenesis and Sertoli cell structure.
Open Access
p63 expression in benign and malignant breast lesions
(Murcia : F. Hernández, 2004) Stefanou, D.; Batistatou, Anna; Nonni, A.; Arkoumani, E.; Agnantis, N.J.
The p63 gene encodes six protein isoforms. The transactivating isoforms have similar actions with p53, while the N-isoforms inhibit transcription activation by p53 and transactivating isoforms. p63 is expressed in stratified epithelia and in basal cells of the prostate and salivary glands. In mammary epithelium p63 has been shown to be expressed only in the myoepithelial layer. In the present study we investigated the immunohistochemical expression of p63, in benign and malignant breast lesions, and compared it with known myoepithelial cell markers. Our material consisted of 140 benign and 126 malignant breast lesions. We used the antibodies anti-p63, anti-a-smooth muscle actin, anti-S-100 protein and anti-cytokeratin 14. In all benign lesions, p63 immunoreactivity was noted in the myoepithelial cell layer surrounding the luminal epithelial cells. A less continuous peripheral rim of myoepithelial cells was also highlighted with p63- staining in all situ carcinomas. All invasive breast carcinomas were devoided of peripheral p63 staining. Interestingly, strong nuclear p63 immunoreactivity was noted in a small fraction (5-15%) of epithelial cells in all cases of papillomatosis, in 62.5% of in situ ductal papillary-type carcinomas and in 33.3% of invasive papillary carcinomas. Comparable staining was observed with S-100. The stromal cells were unreactive to p63. Our findings suggest that p63 is a sensitive and specific myoepithelial marker, and may be included in immunohistochemical panels aiming to identify myoepithelial cells in problematic breast lesions. Regarding papillary neoplasms, it is possible that tumor cells acquire and exhibit at least in part a myoepithelial differentiation program.
Open Access
Extracellular matrix components in atherosclerotic arteries of Apo E/LDL receptor deficient mice: An immunohistochemical study
(Murcia : F. Hernández, 2004) Ström, Å.; Ahlqvist, E.; Franzé, Adela; Heinegård, D.; Hultghrdh-Nilsson, A.
During accelerated vascular remodeling such as in atherosclerosis, the composition of the extracellular matrix becomes altered. The matrix components of the diseased artery influence cellular processes such as adhesion, migration and proliferation. Furthermore, in atherosclerosis, the inability of the cells within the lesion to produce a mechanically stable matrix may lead to plaque rupture. In this immunohistochemical study of atherosclerotic mice aorta, we have reviewed the presence of ECM components with roles in maintaining tissue structure and function. These components include osteopontin and COMP as well as the leucine rich repeats proteins decorin, PRELP, and fibromodulin. Immunohistochemistry demonstrated presence of osteopontin, COMP, decorin, PRELP and fibromodulin in lesion areas of ApoE/LDLr deficient mice. Some advanced lesions exhibited areas of cartilage-like morphology and were shown to represent cartilage by their content of the cartilage specific proteins collagen II and aggrecan. The results suggest that cartilageassociated cell/collagen binding ECM proteins may be involved in the pathogenesis of atherosclerosis.
Open Access
Gastrointestinal stromal tumors: Overview of pathologic features, molecular biology, and therapy with imatinib mesylate
(Murcia : F. Hernández, 2004) Koh, J.S.; Trent, J.; Chen, L.; El-Naggar, A.; Hunt, K.; Pollock, R.; Zhang, W.
Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal tumors of the gastrointestinal tract. These tumors develop at any site but are most commonly reported in the stomach. They originate from the neoplastic transformation of the intestinal pacemaker cell, the interstitial cell of Cajal. GISTs strongly express the receptor tyrosine kinase KIT and have mutations in the KIT gene, most frequently in exon 11 encoding the intracellular juxtamembranous region. Expression of KIT is seen in almost all GISTs, regardless of the site of origin, histologic appearance, or biologic behavior, and is therefore regarded as one of the key diagnostic markers. Distinction from smooth muscle tumors, such as leiomyosarcomas, and other mesenchymal tumors is very important because of prognostic differences and therapeutic strategies. Predicting the biologic behavior of GISTs is often difficult by conventional pathologic examination; tumor size and mitotic rate are the most important prognostic indicators. The prognostic significance of KIT mutations is controversial and thus far has not been clearly linked with biologic behavior. KIT mutations are associated with tumor development, and cytogenetic aberrations are associated with tumor progression. The pathogenesis of GISTs involves a gainof- function mutation in the KIT proto-oncogene, leading to ligand-independent constitutive activation of the KIT receptor. KIT-wild-type GISTs have shown mutually exclusive platelet-derived growth factor receptor (PDGFR) mutation and activation. The use of imatinib mesylate (also known as Gleevec or STI-571) has greatly increased the therapeutic efficacy for this otherwise chemotherapy-resistant tumor. GISTs with very low levels of KIT expression may respond to imatinib mesylate therapy if the receptors are activated by specific mechanisms. KIT-activating mutations fall into two groups: the regulatory type and the enzymatic site type. The regulatory type of mutation is conserved at the imatinib binding site, whereas the enzymatic site mutation has a structurally changed drug-binding site, resulting in drug resistance. Resistance to the drug is the major cause of treatment failure in cancer therapy, emphasizing the need for researchers to understand KIT signaling pathways so as to identify new therapeutic targets. This review summarizes the pathologic features of GISTs, recent advances in understanding their molecular and biologic features, and therapy with imatinib mesylate.
Open Access
Growth performance and histological intestinal alterations in piglets fed dietary raw and heated pigeon pea seed meal
(Murcia : F. Hernández, 2004) Mekbungwan, A.; Yamauchi, K.
Histological intestinal villus alterations were studied in piglets fed raw (PM) or heated (HPM) pigeon pea seed meal. The trypsin inhibition rate was 99.15% in PM and 54.31% HPM. The PM and HPM were added into the basal diet (crude protein; 176.3 g.kg-1, gross energy; 4.15 kcal/g, control) at 20% and 40% levels, respectively. The diets were formulated in order to adjust protein to 180 g.kg-1 and gross energy to about 4.20 kcal/g. The feed intake was not different among groups. The daily body weight gain and feed efficiency tended to decrease with the increasing PM level, and they decreased significantly in the 40% PM group compared with the control group (P < 0.05). However, HPM groups showed a growth performance similar to the control. The villus height, cell area and cell mitosis tended to decrease with the increasing PM level, and they decreased significantly in the 40% PM group compared with the control group (P < 0.05). In HPM group, these villus height, cell area and cell mitosis were significantly higher than those of the 40% PM group (P < 0.05), and did not show a significant difference compared with the control. Compared with the duodenal villus surface of the control group, the PM groups had a smooth surface due to flat cells and the HPM group showed a rough surface due to protuberated cells. The current histological alterations of intestinal villi demonstrate that the villi might be atrophied in the piglets fed raw PM due to anti-nutritional factors, resulting in the decreased growth performance, and that heating PM might abolish such a harmful effect of the anti-nutritional factors on the villus function, resulting in a similar growth performance to the control. Raw PM could be incorporated under a level of 40%, but heated PM increases the incorporation rate up to the 40% level.
Open Access
ldentification of extraretinal photoreceptors in the teleost Phoxinus phoxinus
(Murcia : F. Hernández, 2004) Álvarez-Viejo, M.; Cernuda-Cernuda, R.; Álvarez-López, C.; García-Fernández, J.M.
The existence of cells capable of detecting changes of the photoperiod within the deep brain, the socalled deep brain photoreceptors, was proposed in the early years of the twentieth century. By using immunocytochemistry with antisera against phototransductory proteins on paraffin and vibratome sections, we have localized severa1 positive areas in the brain of the teleost Phoxinus phoxinus. These areas were restricted to two encephalic regions: the epithalamus and the hypothalamus. Immunopositive (rod-opsin- and a-transducin-like) pinealocytes and parapinealocytes, as well as some sparse neurons in the habenula, were seen in the epithalamus. The irnmunoreaction of the hypothalamus was represented by a-transducin-like positive (magnocellular and parvicellular) neurons of the Nucleus Preopticus, as well as by a-transducin- and arrestin-like positive fibers corresponding to the hypothalamic-hypophyseal tract and a few fibers running towards the basa1 telencephalon. These findings corroborate the data published on other teleost fish and fully support the hypothesis of the presence of photosensitive cells in the encephalon of lower vertebrates. The labelling with antisera against different components of the phototransductory cascade also strengthens the idea that such cells employ a biochemical mechanism similar to that in the retinal visual photoreceptor cells, rods and cones. Although the function is still unclear, the detection of the photoperiod seems to be the most likely role for these extraretinal photoreceptors.
Open Access
Bcl-2 protein in normal, hyperplastic and neoplastic breast tissues. A metabolite of the putative stem-cell subpopulation of the mammary gland
(Murcia : F. Hernández, 2004) Luna-Moré, S.; Weil, B.; Bautista, D.; Garrido, E.; Florez, P.; Martínez, C.
This investigation, though initially designed to examine the possible influence of the Bcl-2 protein on the node-metastasizing capacity of breast carcinomas, was amplified to study the expression of this antiapoptotic protein in normal breast lobules and hyperplastic lesions. We examined paraffin sections of 508 breast carcinomas, stained for Bcl-2, estrogen (ER) and progesterone receptors (PgR) and epithelial membrane antigen, and occasionally for other antigens as well. Only a few cells showing a strong Bcl-2 positivity spotted the tubulo-lobular units of normal resting glands, whereas such cells were relatively numerous in atrophic lobules, and very scarce in the terminally differentiated lactating breast. Columnar and usual types of hyperplasia were exclusively, or almost exclusively, composed of Bcl-2(+), ER(+) and PgR(+) cells. The foci of carcinoma in situ and those of invasive carcinomas were respectively 83% and 66% positive for Bcl-2 in at least 25% of their cells. Even among the invasive carcinomas, Bcl-2(+) cases included 83% and 87% of the ER(+) and PgR(+) cases, respectively (p=0.0001). Though there was a statistically significant inverse relation between Bcl-2 and tumor grade (p=0.0001), no significant association was found between Bcl-2 and lymph node stage. In conclusion, we suggest that normal, hyperplastic and neoplastic breast epithelial cells expressing the anti-apoptotic protein Bcl- 2 are immature cells that ought to form part of the stemcell subpopulation, which is committed to the development and to the maintenance of the normal gland and which gives rise to hyperplastic and neoplastic disorders when its proliferation is deregulated. In ductal proliferative changes Bcl-2 assays may be useful for diagnostic but not for prognostic purposes.
Open Access
Pathogenetic role of BCL6 translocation in B-cell non-Hodgkin’s lymphoma
(Murcia : F. Hernández, 2004) Ohno, H.
Chromosomal translocation affecting the 3q27 band, where the BCL6 gene is localized, is one of the most common genetic abnormalities in non- Hodgkin’s lymphoma of B-cell type (B-NHL). The translocation occurs within the major translocation cluster (MTC) of BCL6, and as the result of translocation either one of the three immunoglobulin (Ig) genes or a heterogeneous non-Ig gene is juxtaposed to the coding regions of BCL6. On the other hand, somatic hypermutation involves the BCL6 gene of not only BNHL but also B-cells from normal individuals. The mutations are clustered within a region of the MTC, suggesting that a common molecular mechanism is operating for the two genetic lesions of BCL6. The Bcl-6 protein is a transcriptional repressor that is an important regulator of lymphoid development and function. The protein is preferentially expressed in germinal center (GC) B-cells of normal lymphoid tissues as well as in a variety of B-NHL subtypes derived from GC B-cells irrespective of whether the BCL6 is rearranged. Although there is no consensus on the effect of BCL6 translocation on the clinical outcome of B-NHL, many studies coincide in showing that a high-level of BCL6 expression at either or both the mRNA and protein levels is a favorable prognostic marker of diffuse large B-cell lymphoma. In vitro evidence suggests that non-Ig/BCL6 translocation transiently enhances the level of Bcl-6 expression, which may perturb a molecular network that controls the differentiation of GC B-cells to Ig-secreting plasma cells, thereby predisposing the B-cells to neoplastic transformation.