Histology and histopathology Vol.16, nº 4 (2001)

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Open Access
Vestibular histofluorescence could be due to accumulation of both the antibiotic and its derivative, streptidine, after acute streptomycin treatment in the guinea pig
(Murcia : F. Hernández, 2001) Meza Ruiz, G.; Barba-Behrens, N.; Granados, O.; Hernandez-Cruz, A.; Toxqui, A.
Acute treatment with 300 mglkg of pigmented guinea pigs with streptomycin sulfate induces an elevation of endogenous fluorescence in vestibular ampullary cristae. Fluorescence accumulates in all compartments of the epithelium, i.e., vestibular sensory and supporting cells and nerve fibers of the stroma and it was very intense 1 and 12 hours after its administration. Fli~orescence decreased to control levels 24 hours following streptomycin injection. Fluorescence levels were very low either in untreated animals or in animals injected with s a l i n e physiological solution. To investigate whether this fluorescence was an intrinsic property of the antibiotic or whether it was due to a derivative of it, or both, an in vitro fluorescence spectrum was performed with I00 ,LIM solutions of streptomycin or streptidine, or both, dissolved in various buffer solutions at 488 nm of excitation. A discrete level of fluorescence was observed in the spectrum regardless of media when separate solutions of both streptomycin or streptidine were s t u d i e d . Fluorescence notably increased at 522-532 nm when the solutions contained both streptomycin and streptidine toget her. These results suggest that streptidine putatively derived from streptomycin may contribute to the observed fluorescence accumulation in vestibular preparations after acute treatment. Thus, these metabolic properties of the inner ear which transform streptomycin into streptidine, something never considered earlier, could be claimed as partially responsible for converting a therapeutic agent into a compound which could be as harmful as STP to the inner ear.
Open Access
Villous trophoblast of human placenta: a coherent view of its turnover, repair and contributions to villous development and maturation
(F. Hernández y Juan F. Madrid. Universidad de Murcia: Departamento de Biología Celular e Histología, 2001) Mayhew, T. M.
J\ coh e re nt vicw o f hum a n v illou s trophoblast as a continuously renewing epithelium is presented. Epithelia undergoing continuous rcnewal (e.g. intestinal mucosa, epidermis) display clonogenic ce lls which pass throug h sevc ral transit di visions be fore migrating out of proliferation zones and into zones of maturati on/differenti ati on. Quantitative relations (e.g. re lati ve numbers of cells) betwee n proliferati on and diffe rentiation zones help to define the steady state and this may va ry in res po nse to ph ysi o log ic al and pathological circumstances. From the differenti ati on compartment, ce lls or ce ll fr agments arc eve ntu all y extruded by mechanisms which may involve apoptosis. All these features are seen in trophoblastic epithelium. Cy totrophobl ast ce lls (CT, proliferation zone) divide continuously throughout gestation and post-mitotic cells are recruitcd into syncytiotrophoblast (ST, diffe rentiation zone) aft cr membrane fusion. Evidence of fu sion events includes localised confluence of CT and ST cytoplasms, and intrasy ncyti al plasma membrane segments bearing desmosomal remn ants. During diffe renti ati on, nu clei undergo changes in shape, chromatin condensation and packing densit y. Densely-clustered nuclei are associated with cy tokeratin intermed iate fil aments and annul ate lamellae . Both clustered and non-clustered nuclei show ultrastructural fea tures of pre-apoptosis and apoptosis. Normall y, apoptosis is triggered only when nuclei are in the syncytium. Some (pre-)apoptotic nuclear aggregates are se qu este red in sy nc yti a l knots, extrud ed as troph obl ast fr agments into the intervill ous space and th e n depo rt ed int o th e mate rn a l c irc ul ati o n to be ph agocytosed at extrapl acental sites. During gestation, there is some constancy in the numerical ratios between CT and ST nuclei pointing to a normal steady state. The steady state may be perturbed when the epithelium is damaged loca ll y. Whe re the epithelium is denud ed, fibrin-type fibrinoid from the intervillous space plugs the discontinuity and , with CT proliferation, facilitates reepitheli alisation. Features of normal villous development (e.g. sprouting, int ervillous bridge formati on, bridge abrupt ion, sy ncytial knot formation) arc explicable in the co nt ex t of tr o ph obl ast turn ove r with ea rl y CT pro li fe rati o n be in g ma inl y fo r g row th a nd la te r proliferation for renewa l and repair. Adaptive re-settings of the epithelial steady state may also occur in abnormal pregnancies.
Open Access
Consecutive light microscopy, scanning-transmission electron microscopy and transmission electron microscopy of traumatic human brain oedema and ischaemic brain damage
(Murcia : F. Hernández, 2001) Castejon, O.J.; Castejon, H.V.; Diaz, M.; Castellano, A.
Cortical biopsies of 11 patients with traumatic brain oedema were consecutively studied by light microscopy (LM) using thick plastic sections, scanning-transmission electron microscopy ((S)TEM) using semithin plastic sections and transmission electron microscopy (TEM) using ultrathin sections. Samples were glutaraldehyde-osmium fixed and embedded in Araldite or Epon. Thick sections were stained with toluidine-blue for light microscopy. Semithin sections were examined unstained and uncoated for (S)TEM. Ultrathin sections were stained with uranyl and lead. Perivascular haemorrhages and perivascular extravasation of proteinaceous oedema fluid were observed in both moderate and severe oedema. Ischaemic pyramidal and non-pyramidal nerve cells appeared shrunken, electron dense and with enlargement of intracytoplasmic membrane compartment. Notably swollen astrocytes were observed in all samples examined. Glycogen-rich and glycogen-depleted astrocytes were identified in anoxic-ischaemic regions. Dark and hydropic satellite, interfascicular and perivascular oligodendrocytes were also found. The status spongiosus of severely oedematous brain parenchyma observed by LM and (S)TEM was correlated with the enlarged extracellular space and disrupted neuropil observed by TEM. The (S)TEM is recommended as a suitable technique for studying pathological processes in the central nervous system and as an informative adjunct to LM and TEM.
Open Access
Characterization of GFAP expression and cell proliferation in the rat median eminence following hypophysectomy
(F. Hernández y Juan F. Madrid. Universidad de Murcia: Departamento de Biología Celular e Histología, 2001) Vázquez, R.; Blanco, E.; Sánchez, F.; Juanes, J. A.; Rubio, M.; Santos, M.; Vázquez, G.; Hernández, E.; Riesco, J. M.; Carretero, J.
To analyze whether the reorganization of the rat medi an emin ence aft er hypophysectomy might be related to changes in gli al fibrill ary ac idi c protein (GFAP)- and cellular prolife ration, th e distribution of cells immunoreactive for GFAP and the prolife ration rate of such cells were analyzed at 20, 40 and 60 days posthypoph ysec tomy. Fo r this stud y, four rostra -ca ud al regions of the medi an eminence we re diffe renti ated: the retroc hi as mati c, preinfundibul a r, infundi bul ar and postinfundibul ar regions. In each of these regions, three layers were studied: the ependymal, the internal and the ex tern al. At 20 and 40 days aft er hypoph ysec tomy, significant increases in ce llular proliferation affecting all three laye rs studi ed in th e pre infundi bul a r a nd infundibul ar regio ns we re fo und . At the same time po ints, in c reases in GFAP ex pr essio n we re a lso obse rved . Howeve r, a ft e r 60 days, GFA P a nd proliferative ce llular nuclear antigen (PCNA) expression dec reased. Although va ri ati ons of PCNA and GFA P levels were ev id ent, no coloca lisa ti on of PCNA and GFAP was fo und in the cells of the medi an eminence in untreated or hy pophysectomized rats when sections we re analyzed by double immunohistochemica l staining. Our results suggest that reorgani zation of med ian eminence in vo lves alt e rati o ns (o r modul ati o n) o f GFA Pimmunoreacti ve ce lls together with a proliferation of cells that are not GFAP-immunoreactive. This study also demonstrates that this reorgani zation is completed within the fi rst two months afte r hypophysectomy.
Open Access
Acute and chronic estrogen supplementation decreases uterine sympathetic innervation in ovariectomized adult virgin rats
(F. Hernández y Juan F. Madrid. Universidad de Murcia: Departamento de Biología Celular e Histología, 2001) Zoubina, E. V.; Mize, A. L.; Alper, R. H.; Smith, P. G.
Uterine innervation undergoes substantial reorganization associated with changes in reproductive status. Nerves innervating the uterus are decreased in pregnancy and puberty, and even the normal rodent estrous cycle is characterized by fluctuations in numbers of myometrial nerve fibers. During the follicular (proestrus/estrous) phase of the estrous cycle, intact nerves are rapidly depleted and then return over the next 2-3 days in the luteal (metestrus/diestrus) phase. We hypothesize that uterine nerve depletion is initiated by increased circulating estrogen in the follicular phase . However, studies have not shown whether estrogen can reduce uterine innervation and, if so, whether the time course is compatible with the rapid changes observed in the estrous cycle. These questions were addressed in the present study. Mature ovariectomized virgin rats received 17-B-estradiol as a single injection (10 .ug/kg s.c.) or chronically from timed-release pellets (0.1 .ug/pellet for 3 weeks sustained release). Total (protein gene-product 9.S-immunoreactive) and sympathetic (dopamine B-hydroxylase-immunoreactive) uterine innervation was assessed quantitatively. Both total and sympathetic innervation was abundant in uterine longitudinal smooth muscle of ovariectomized rats. However, following acute or chronic estrogen administration, total and sympathetic fiber numbers were markedly decreased. This was not due to altered uterine size, as reductions persisted after correcting for size differences. Our results indicate that sympathetic nerves are lost from uterine smooth muscle after estradiol treatment in a manner similar to that seen in the intact animal during estrus and pregnancy. This suggests that the rise in estradiol prior to estrus is sufficient to deplete uterine sympathetic innervation.
Open Access
Expression of integrin αvβ3 in pig, dog and cattle
(F. Hernández y Juan F. Madrid. Universidad de Murcia: Departamento de Biología Celular e Histología, 2001) Singh, B.; Rawlings, N.; Kaur, A.
The avlB integrin, also known as vitronectin receptor, is an adhesive glycoprotein that promotes angiogenesis in the embryo and tumors such as melanoma. Integrin avID is one of the receptors for adenovirus and hantavirus. There is little information on the constitutive expression of this integrin especially in animal species that are used for biomedical research. We used light and elec tron microscope immunocytochemistry and western blots to determine integrin avB3 expression in seven organs in the pig, dog and cattle. Immunohistology showed the integrin expression on the epithelium of small intestine , bile duct and renal proximal convoluted tubules in three species. The airway epithelium revealed a weak reaction for integrin avB3. Skin showed the integrin in occasional extravascular cells while skeletal muscles were negative. The integrin was expressed only in bronchial vasculature in the lung and occasional dermal microvessels. Many mononuclear cells in the lung and spleen stained for integrin avB3. Immunogold electron microscopy revealed the expression on the epithelium but not on the vasculature of the small intestine. Western blots detected integrin avB3 in small intestine and lung but not in skeletal muscles. We conclude the integrin is expressed on the epithelium but not in the vasculature. The expression differs strikingly among organs in the same pecies although the inter-species differences are minor. Restriction of the integrin to absorptive epithelia of small intestine and kidney may suggest its putative role in endocytosis. Because the integrin is a receptor for adenovirus, these data may be relevant to gene therapy studies.
Open Access
lmmunohistochemical expression of p53, p21/waf1, Rb, p16, cyclin D1, p27, Ki67, cyclin A, cyclin B1, bcl2 bax and bak proteins and apoptotic index in normal thymus
(Murcia : F. Hernández, 2001) Kanavaros, Panagiotis; Stefanaki, K.; Rontogianni, D.; Papalazarou, D.; Sgantzos, M.; Arvanitis, D.; Vamvouka, C.; Gorgoulis, V.; Siatitsas, I.; Agnantis, N.J.; Bai, M.
The immunohistochemical expression of p53, p21, Rb, p16, cyclin D1, Ki67, cyclin A, cyclin B1, p27, bc12, bax, and bak proteins and the apoptotic index (AI) were investigated in 20 normal thymuses (8 adults, 3 adolescents, 5 infants and 4 newborns). The expressions of Rb, Ki67, cyclin A and cyclin B1 were overlapping, being high in the cortex with a tendency for decreased expression toward the medulla. Apoptotic cells were mainly detected in the cortex and the corticomedullary junction, rarely being present in Hassall's corpuscles. The mean values of Ki67, cyclin A, and cyclin B1 expression in thymuses were 77.2%, 32.2% and 21.4% (newborns), 62.4%, 33.7% and 18.5% (infants), 56.9%, 23.4% and 18.9% (adolescents) and 38.7%, 21.7% and 14.6% (adults), respectively. The mean values of AI in thymuses from newborns, infants, adolescents and adults were 1.4%, 2.9%, 2.7% and 3.8%, respectively. This decrease in proliferation and increase in apoptosis may account for the process of thymic involution. P16 expression was widespread with most of Hassall's corpuscles being pl6-positive. P16- positive cells and Hassall's corpuscles increased with the increase in age, in keeping with the suggested role of p16 in cellular senescence. P27 expression was undetectable in subcapsular thymocytes with a tendency for increased expression toward the medulla. The expressions of Ki67, cyclin A and cyclin R1 were inversly related with that of p27, consistent with previous evidence that p27 concentration is reduced when the cell-cycle progresses. P21 and much less frequently p53 proteins were mainly detected in a part of the subcapsular cortical epithelial cells. These findings suggest that a) in thymocytes, the apoptotic pathway is mostly p53-independent and the function of p21 as a negative regulator of the cell cycle must be redundant to other negative regulators, such as p16 and p27 which were abundantly detected in thymocytes and b) in some thymic epithelial cells, the p21 expression may be induced by p53, but in most of them seems to be p53- independent. Most of Hassall's corpuscles were p21- positive, consistent with previous evidence that these structures represent end stages of maturation of thymic medullary epithelium and that p21 protein is involved in the process of terminal differentiation. Cyclin D1 positivity was found in some macrophages. Rc12 expression was mainly seen in medullary thymocytes, reflecting the surviving thymocytes in this region. The expressions of Bax and bak were more widespread in both the medulla and cortex, suggesting that these proteins play a broader role than bc12 in the regulation of thymic apoptosis.
Open Access
Synthesis of calcitonin gene-related peptide (CGRP) by rat arterial endothelial cells
(F. Hernández y Juan F. Madrid. Universidad de Murcia: Departamento de Biología Celular e Histología, 2001) Doi, Y.; Kudo, H.; Nishino, T.; Kayashima, K.; Kiyonaga, H.; Nagata, T.; Nara, S.; Morita, M.; Fujimoto, S.
We investigated the protein and mRNA expression of calcitonin gene-related peptide (CGRP) in endothelial cells of the rat thoracic aorta and femoral artery. Light microscopic immunocytochemistry revealed that immunoreactivity for CG RP was preferentially located in the endothelium of both vessels. Immunoelectron microscopy showed that CGRPimmunoreactive gold particles were preferentially localized on cisterns of the rough endoplasmic reticulum and on the Weibel-Palade (WP) bodies in the endothelial cells. Prepro CGRP mRNA signals were also detected on the endothelium. Our results are the first to demonstrate that endothelial cells of both elastic and large muscular arteries synthesize CGRP and store it, in part, in WP bodies, implying that CGRP may act as an endothelium-derived relaxing factor in these vessels.
Open Access
The ultrastructural composition of basement membranes in vivo
(Murcia : F. Hernández, 2001) Miosge, Nicolai
The ultrastructure of basement membranes has a homogeneous appearance. The enormous cell biological importance of basement membranes and their components f o r c e l l proliferation, migration and differentiation implies that their composition is more complex than their structure suggests. To elucidate the molecular composition of basement membranes it1 vivo, we optimised immunogold histochemistry to allow the determination of the molecular arrangement of matrix molecules. Basically, we apply a mild fixation and embed the tissues in the hydrophilic L R - G O ~T~h~is .p reserves the basement membrane with a quality similar to freeze substitution. The application of two antibodies directed toward the C- and N-terminal ends of a molecule and coupled to gold particles of different sizes allows determination of the orientation of a molecule within the basement membrane. We were able to demonstrate that the molecular orientation of the laminin-l molecule changes in the basement membrane according to cell biological needs. We also showed that ultrastructurally identical basement membranes like the ones of the proximal and distal tubules of the kidney have a differing molecular arrangement. Integrin a7 influences the molecular composition of the basement membranes at the myotendinous junction. With the help of double labelling at the ultrastructural level we could show that nidogen-l is CO-localised with laminin-l and only found in fully developed, mature basement membranes. In general, laminin-l, nidogen-l and collagen type IV are localised over the entire width of basement membranes, with laminin-l and nidogen-l CO-localised, in accordance with the current basement membrane models. Incidentally, our investigations warn us, that not every matrix protein found at the light microscopic level as a linear staining pattern underneath an epithelium (basement membrane zone) is a real basement membrane component when investigated at the ultrastructural level. Instead, one and the same molecule, e.g. endostatin, can be a basement membrane component in one organ and a matrix molecule in another.
Open Access
Cytochemical localization of Na+/K+ -ATPase activity in cochlear strial marginal cells after various catecholamine administrations
(Murcia : F. Hernández, 2001) Kanoh, N.; Dai, C.F.; Mohri, D.; Hori, S.
Sodium/potassium-activated adenosine triphosphatase (Na+/K+-ATPase) activity in the kidney and brain is high, and is regulated by catecholamines. Na+/K+-ATPase activity is also high in the basolateral infoldings of the strial marginal cells, where it aids in maintaining the characteristic electrolyte composition of the endolymph. To clarify the involvement of humoral control in strial function, particularly the role of catecholamines, the K+-dependent p-nitrophenylphosphatase (K+-NPPase) activity of strial marginal cells was investigated in guinea pigs using a ceriumbased cytochemical method. The effects of reserpine, serotonin (5-HT), norepinephrine (NE), epinephrine (EP), both alone and in combination, were studied. High doses of reserpine cause depletion of sympathetic substances. Stria1 K+-NPPase activity was decreased after reserpine or dopamine treatment, and was increased after 5-HT, NE, and EP treatment. After reserpinization, repeated treatment with 5-HT, NE, or EP led to detectable strial enzyme activity. Thus, exogenous 5-HT, NE, and EP were able to restore strial K+-NPPase activity in the reserpine-treated animals. These results suggested that biogenic amines regulate strial K+- NPPase activity. Thus, the function of the stria vascularis may be regulated by the opposing actions of these catecholamines, and 5-HT.
Open Access
Tissue and molecular events in human conjunctival scarring in ocular cicatricial pemphigoid
(F. Hernández y Juan F. Madrid. Universidad de Murcia: Departamento de Biología Celular e Histología, 2001) Razzaque, M. S.; Foster, C. S.; Ahmed, A. R.
Detail ed histomo rph ometric analysis of human conjunctiva l biopsy specimens has convincingly demonstrated that tissue remodeling of the extracellular matri x (EC M) is an esse nti al and dy nami c process associated with conjuncti val sca rring in ocul ar cicatricial pemphi go id (OCP). The co njun cti va l sca rring ofte n eventuall y results in impaired vision and/or blindness. The molecul ar mechanisms of conjunctival scarring are not compl etely und erstood. Acc umulating evidence indicates that the earl y phase of conjunctival fibrosis is linked with an immuno-inflammatory process medi ated by cy tokines released by ac tiva ted conjunctiv al cells and/or by infiltrating cells. Fibrogenic cytokines secreted by infl ammatory cells and fibroblasts might acti vely be in vo lve d in remode lin g o f th e matri x within th e conjunctival stroma, possibly by regul ating the altered metabolism of matrix proteins.
Open Access
Hepatitis C virus-associated mixed cryoglobulinemia. Clinical manifestations, histopathological changes, mechanisms of cryoprecipitation and options of treatment
(Murcia : F. Hernández, 2001) Schott, P.; Hartmann, H.; Ramadori, G.
Chronic hepatitis C virus (HCV) infection is frequently associated with a variety of autoimmune phenomenons. Mixed cryoglobulinemia (MC) appears in up t o 50% o f chronic HCV-infected patients. Cryoglobulins consist of immunoglobulin complexes precipitating in vitro when cooled below body temperature. In most cases IgM with rheumatoid factor activity is found in cryoprecipitates which could lead to vasculitis induced by the deposition of immnuocomplexes in small vessels. This vasculitis is thought to cause clinical symptoms called Meltzer's triad. This triad is represented by purpura, arthralgia and weakness. One third of patients suffering from HCV-associated mixed cryoglobulinemia are developing typical symptoms during their course of disease. The striking association between HCV infection and MC has conduced to the hypothesis that HCV is of major importance in the production of MC with followed vasculitis. Both hepatrophism and lymphotrophism have been reported for the hepatitis C virus. Infection of B-cells by HCV could probably lead to a bcl-2 translocation and immunoglobulin gene rearrangement which results in clonal lymphoproliferation and in synthesis of monoclonal IgM with rheumatoid factor activity. These IgM form immunocomplexes with IgG in the cold which are finally responsible for the described vasculitis. Histopathological changes of the liver are dominated by chronic HCV infection. The majority of times mild activity of hepatitis or mild fibrosis could be found. Nevertheless, cirrhosis is more often found in HCVinfected patients suffering from MC compared to patients without MC. Conventional treatment of MC is aimed to reduce circulating immune complexes by immunosupression and plasmapheresis. With the emerging concept of a viral pathogenesis the therapeutic approach has changed during the last decade. Interferon treatment of MC, particularly of HCV-associated MC is well established nowadays.
Open Access
TGF-ß1 and IL-6 expression in rat pineal gland is regulated by norepinephrine and interleukin-1 ß
(F. Hernández y Juan F. Madrid. Universidad de Murcia: Departamento de Biología Celular e Histología, 2001) Tsai, S. Y.; Schluns, K. S.; Le, P. T.; McNulty, J. A.
T he pineal g land is part of th e neur oendoc rin e system that modulat es immun e functions. Beca use the gland is outside the blood-brain barrier, il is accessibl e to dir ec t feedback from circul atin g cyto kin es that affec t th e sy nth esis and secreti on of melatonin . Recent studi es have suggested that intrinsic immunoregul atory cytokines med iate these neuro-immune int e ra cti o ns und er th e co ntr o l of sympathetic innervation to the pineal. This study focused on th e expression of transfo rmin g growt h factor-f3 1 (TGF-f3I) and interl eukin-6 (IL-6), two cy toki nes th at have important regula tory functions on both neurons and immune cells. Northern blot RNA analysis showed that TGF-f3l, but not IL-6, was expressed in freshly dissected rat pineal glands from neo natal age (l -day-o ld) into ad ults. Immun ocy toc hemistry for TGF-B1 in adult glands revealed localization of this protein in astrocy telik e cells. The sy mp ath e tic ne ur o tr ansmitt e r norepinephrine (NE) increased transcript levels for both TGF-f31 and IL-6 in adu lt pinea l organ cultures. The effect of NE o n I L-6 exp ressio n was not found in dispersed cell cultures established from neonatal pineal glands. The immunoregul atory molecule interleukin-l/3 (IL-l /3) up-regulat ed th e expression of both IL-6 and TGF-/31 in ad ult pineal organ cultures, but not in neonate pineal organ cultures. These findings suggest that TGF- /31 and IL-6 have intrinsic regul atory roles in the pinea l gland and that both neural and immune factors are important mechanisms of regulation.
Open Access
Tight junctions and their role in cancer metastasis
(F. Hernández y Juan F. Madrid. Universidad de Murcia: Departamento de Biología Celular e Histología, 2001) Martin, T. A.; Jiang, W. G.
Tight Junctions gove rn the permeabili ty of endothelial and epithelial cells and are the most topical structures of these cell types. Tight junctions create an intercell ular ba rri er and in tramembrane diffusion fe nce. An important step in the fo rmation of ca ncer metastases is int e rac ti on and pe netrat io n o f th e vasc ula r endothelium by dissociated ca ncer cells. Ea rly studies demonstrated a correlation between the reduction of tight junctions and tumour diffe rent iati on and experimental evidence has emerged to pl ace tight junctions in the frontline as the structure that ca ncer cells must overcome in order to metastasise. Changes in tight juncti on function are thu s an ea rl y and key aspect in cancer metastasis. Further work is requ ired to fully realise the potent ial that this structure has in cancer invasion and metastasis in ord er to deve lop new and nove l th erapi es in th e prevention of tumour metastasis.
Open Access
Analysis of the in vivo dend ritic cell response to the bacterial superantigen staphylococcal enterotoxin B in the mouse spleen
(F. Hernández y Juan F. Madrid. Universidad de Murcia: Departamento de Biología Celular e Histología, 2001) Yoon, S.; Bae, K. L.; Shin, J. Y.; Yoo, H. J.; Lee, H. W.; Baek, S. Y.; Kim, B. S.; Kim, J. B.; Lee, H. D.
To inv esti ga te th e in vi vo effec ts of St
Open Access
Comparative study of the acute toxicity of anionic surfactans alky benzene sulphonate (ABS) and sodium dodecyl sulphate (SDS) on gilthead, Sparus aurata L., eggs
(Murcia : F. Hernández, 2001) Rosety, M.A.; Ordóñez Muñoz, F.J.; Rosety-Rodriguez, M.; Rosety, J.M.; Rosety, I.; Carrasco, C.; Ribelles, A.
In the present work we have evaluated the acute toxicity of two anionic surfactants, alkyl benzene sulphonate (ABS) and sodium dodecyl sulphate (SDS) to eggs of gilthead Sparus aurata. At each surfactant concentration, we determined the exposure time required for 50% mortality of the eggs (LT50), surface tension and volume of oil globule in gilthead eggs. Clear dose-response relationships for mortality of gilthead eggs was observed for both toxicants; at 30 mg/L 50% mortality took place at 45 minutes for ABS and 8 minutes for SDS. At this concentration, SDS was almost six times more toxic than ABS (LT50 is compared). However, at 0.3 mg/L 50% mortality occurred after exposures of 535 minutes to ABS and 425 minutes to SDS. Descriptively, our results showed SDS was more toxic than ABS at high concentrations whereas at low concentrations their toxicity was very similar. However, statistical analysis demonstrated there were no significant differences in the toxicity of both surfactants to gilthead eggs. Surface tension value at each concentration of both surfactants was also calculated. We found that these values decreased with increasing concentration of each surfactant, and this trend was more pronounced in solutions of SDS. We also found that the volume of the oil globule of exposed eggs was influenced by surfactants. After exposure, its volume clearly decreased in comparison to controls, mainly in eggs exposed to SDS.
Open Access
Co-localization of integrins and matrix metalloproteinases in the extracellular matrix of chondrocyte cultures
(F. Hernández y Juan F. Madrid. Universidad de Murcia: Departamento de Biología Celular e Histología, 2001) Schulze Tanzil, Gundula; de Souza, P.; Merker, H. J.; Shakibaei, M.
ß1-int eg rin s we re found in th e ca rtil age matri x, suggesting their implication in the assembly of its architectural sca ffold , but the mechanism fo r this event is not yet clear. Matrix metalloproteinases (MMPs) may be involved in an int egrin -shedding mechanism and matri x 131- integrins may ac t to alter MMP activity. To begin to address this qu esti o n, this stud y was desig ned to determin e wheth er ß1-in teg rin s and MMPs arc colocali zed in th e chondrocy tes or in the ex trace llul ar matrix of cartil age. We investigated high-densit y cultures of limb buds of 12-day -old mo use embryos by double immunoflu o re ce nce, immun oe lectron mi c rosco py and by coimmunoprccipitation assays in order to examine the loca li za ti o n o f ß1-int egrin s and matri x me ta ll oproteinases (MMP-1, MMP-3 and MMP-9) in cartilage. It was found , that all investigated MMPs and 13 1- integrins we re specifically co-loca li zed in high-density cartil age cultures. Immunogold and immunofluorescence labelling of both ß1-integrins and MMPs were observed not only at the surface of chondrocytes but mainl y also in th e pe rice llul ar space a nd distributed be tw ee n coll agen fibrils in th e ex trace llular matrix (ECM) as we ll. Res ults o f immun oprecipitati o n ex pe riments suggest a fun cti onal assoc iati on of MMPs and 13 Lintegrins in chondrocytes as already described fo r other cell types. Further investigations are needed to elu cidate the fun ctional association between Bl-integrins and MMPs in chondrocytes.
Open Access
Transcriptional mRNA of BMP-2, 3, 4 and 5 in trigeminal nerve, benign and malignant peripheral nerve sheath tumors
(F. Hernández y Juan F. Madrid. Universidad de Murcia: Departamento de Biología Celular e Histología, 2001) Jin, Y.; Lu, H. B.; Liong, E.; Lau, T. Y. H.; Tipoe, G. L.
The aim of our study was to document whether relationships existed among bone morphogenetic proteins (BMPs), peripheral nerve and neoplastic lesions of nerve sheath tumors. The mRNA transcriptions of BMP-2, 3, 4 and 5 in 10 cases of schwannoma, three cases of malignant schwannoma and two cases of trigeminal neuralgia were detected using an in situ hybridization technique. Our results demonstrated that the myelin sheaths of Schwann cell from the pe ripheral neuroectomy of trigeminal neuralgia positively expressed mRNA of BMP-2, 3, 4, and 5. The most interesting finding was that the nerve fibers of trigeminal nerve showed only BMP-2 positive staining. All of the neoplastic lesions of nerve sheath showed a consistent but variant expression of BMP-2, 3, 4, and 5. The expression signals of BMP-2 , 3, 5 mRNA in malignant schwannoma were relatively lower than in benign lesions except for the expression of BMP-4 mRNA. Our results indicated that selected members of BMPs were expressed in the peripheral nerves that might contribute to the health maintenance, proliferation, regeneration and neoplastic transformation of the peripheral nerve system. Furthermore, the effects of BMP-2, 3, 4 and 5 on peripheral nervous system during neoplastic transformation might be widespread, diverse and antagonistic.
Open Access
Expression of the retinoblastoma-related p107 and Rb2/p130 genes in human placenta: an immunohistochemicaI study
(Murcia : F. Hernández, 2001) Cavallotti, I.; De Luca, L.; D'Aponte, A.; De Falco, M.; Acanfora, F.; Visciano, M.L.; Gualdiero, L.; De Luca, B.; Baldi, A.; De Luca, A.
It has been proposed that tumor suppressor genes may have a role in the mechanisms of proliferation and differentiation during human placental development. The Retinoblastoma gene family is a well known family of tumor suppressor genes. Many studies have pointed out a role of this family not only in cell cycle progression, but also during development and differentiation. On the light of these observations we have investigated the immunohistochemical expression pattern of the Retinoblastoma family members, p107 and Rb2/p130 in human placenta samples in first trimester and full-term placental sections. p107 and pRb2lp130 showed the most abundant expression levels during the first trimester of gestation and progressively declined to being barely detectable in the placenta by late gestation. These results indicate that the expression of the above genes is modulated during placental development and suggest a mechanism for controlling trophoblast proliferation.
Open Access
Comparison of NADPH diaphorase activity in the brains of hamsters infected with scrapie strains 139H or 263K or with normal hamster brain homogenate
(F. Hernández y Juan F. Madrid. Universidad de Murcia: Departamento de Biología Celular e Histología, 2001) Ye, X.; Meeker, H. C.; Scallet, A. C.; Carp, R. I.
Previous studies showed that the histopathological changes found in the brains of scrapieinfected animals included amyloid plaque formation, vacuolation , gliosis and neuronal and neurite degeneration. There were differences in the histopathological findings as a function of the scrapie strain-host combination. NADPH-diaphorase (NADPHd) has been shown to be a selective histoch emical marker for neurons containing nitric oxide (NO) synthase. Neuronal cell damage caused by NOS in brain has been reported to be associated with many neurodegenerative diseases. In this study, we used NADPH-d histostaining to investigate changes in the NOS system in brains of 139H- and 263K-infected hamsters and compared the results to normal hamster brain (NHB) injected animals. We observed that some of the NADPH-d histostaining neurons in the cortex of scrapie-infected hamsters appeared to be atrophic: the neurons were smaller and had fewer neurites. The NADPH-d histostaining intensity of neurons or astrocytes in septum, thalamus, hypothalamus and amygdala of 139H- and 263K-infected hamsters was greater than in control hamsters. Astrocytes in the thalamus, hypothalamus and lower part of the cortex (layers 4 to 6) in 263K-infected hamsters were more intensely stained for NADPH-d than in either 139Hinfected hamsters or controls. Our results suggest that changes in NADPH-d system might playa role in the diversity of scrapie induced neurodegenerative changes.