Tissue response to nano-hydroxyapatite/collagen composite implants in marrow cavity

The formation of otoconia in the endolymphatic sac (ES) of the larval newt, Cynops pyrrhogaster, has been studied by light and transmission electron microscopy. Some of the epithelial cells of the ES contain an abundance of swollen vesicles, Golgi complexes, rough endoplasmic reticula and ribosomes at the late larval stages 50 and 51, approximately 26-30 days after eggs are laid. Five days later, at stage 52, crystals are present in the vacuoles between the epithelial cells. Serial sections indicate that these vacuoles actually form small canals which lie in the wall and join the lumen of the ES. Reconstruction of the ES shows that several canals are contained in the ES wall. At stage 56, about 72 days after eggs are laid, a large number of otoconia are present in the ES lumen, while the otoconia disappear from the canals. It appears that the otoconia are first produced in the canals and then released to the lumen. Some epithelial cells of the ES are thought to expel the organic and inorganic material to the canals to form the otoconia in situ. The process of formation of the otoconia in the ES is discussed.     

Maturation of rat dendritic cells during intrahepatic translocation evaluated using monoclonal antibodies and electron microscopy

Specific populations of hepatic sinusoidal cells were stained with monoclonal antibodies that recognize monocytes/macrophages (ED1), tissue macrophages (Kupffer cells) (ED2), MHC class II (Ia) antigen (MRC OX6), and dendritic cells/gamma,delta T-cells (MRC OX62) and analyzed by light and electron microscopy. The majority of ED1(+) and/or ED2(+) cells were localized to the hepatic parenchyma, whereas OX6(+) and/or OX62(+) cells were more densely distributed within Glisson's sheath than in the hepatic parenchyma. Double-immunoperoxidase staining of normal liver for ED1, ED2, and OX6 identified dendritic cells (DC) of two different phenotypes, ED1(+)ED2(-)OX6(+) and ED1(-)ED2(-)OX6(+). DC can be classified into three different types based on ultrastructural characteristics. The first type (type I) is characterized by one or more long cytoplasmic processes and a well-developed lysosomal system. The second type (type II) has an inconspicuous lysosomal system, abundant hyaloplasm, and characteristic short cytoplasmic processes. The third type (type I-II) has cytologic features intermediate between those of type I and type II DC. At the electron-microscopic level, these three cell types are found in the sinusoidal lumen, whereas the majority of type II DC are located in the space of Disse and Glisson's sheath. Furthermore, some OX6-labeled elongated DC appeared to traverse the lumen of sinusoids through endothelial pores to enter the space of Disse. One hour after intravenous injection of latex particles (0.81 micrometer in diameter), numerous latex-laden dendritic cells (ED1(+)OX6(+), type I and type I-II) were detected in the lumen of hepatic sinusoids, but not in the space of Disse or Glisson's sheath. These findings suggest that normal rat liver contains resident dendritic cells which downregulate phagocytic activity and mature into potent accessory cells during migration from the portal vein toward the central vein. These DC then traverse the sinusoidal lumen to the hepatic lymph system via the space of Disse.     

Formation and fate of giant otoconia of the guinea pig following streptomycin intoxication

Formation and fate of abnormal (giant) otoconia of the guinea pig following streptomycin intoxication were investigated using scanning electron microscopy. The giant otoconia formed as multifaceted morphology in their early developmental period. They grew up the the transitional type and finally to the cylindrical type. It has been suggested that the giant otoconia found following streptomycin intoxication may be formed mainly by dissolution of normal otoconia due to the loss of environmental calcium, followed by recrystallization as giant crystals. These phenomena seemed to be closely related to the otoconial dynamics which may regulate calcium ion homeostasis of the endolymph.     

Methodological approaches to quantitative evaluation of microcirculation in tissues with dynamic magnetic resonance tomography

We observed the process of disappearance of the choriocapillaris after loss of the retinal pigment epithelium (RPE) induced by intravitreal injection or ornithine. Three hours after administration of ornithine, the RPE cells swelled remarkably in the posterior pole, but, the endothelial cells of the choriocapillaris remained intact. At 3 days, the RPE cells became necrotic, but the choriocapillaris still preserved its in normal appearance. At 7 days, RPE disappeared completely in the posterior pole and the choriocapillaris displayed evidence of atrophy; the swollen lumen of the choriocapillaris became narrow the cytoplasm of the endothelium was swollen, and the number of fenestrae was reduced. On the other hand, these changes were not seen where the RPE remained. At 14 days, in the posterior pole, the lumen of the choriocapillaris occluded by the swollen endothelial cells. At 28 days, the choriocapillaris completely disappeared and the large choroidal vessel was directly in contact with Bruch's membrane. These results showed that the RPE is correlated with the presence of the choriocapillaris.     

Antigen removal after inoculation into the endolymphatic sac of immunized guinea pigs

Antigen removal in the endolymphatic sac (ES) was immunohistochemically examined. Forty-five adult female Hartley guinea pigs were used in this study. After keyhole limpet hemocyanin (KLH) systemic immunization, KLH was directly injected into the lumen of the right ES. The presence of KLH was detected in histological sections using immunohistochemistry. After KLH challenge into endolymphatic sac lumen, high concentrations of KLH were diffusely found within phagocytes in the endolymphatic lumen and peri-saccular tissue on day 2. After day 14, KLH disappeared from the immunized inner ear. The above results suggest that KLH is removed from the inner ear by diffusion through the endolymphatic epithelial cells which have altered permeability or by phagocytosis of the phagocytic cells. No KLH was observed in the left endolymphatic sac and bilateral cochlea as well as vestibular organ during 5 months of follow up. This study showed that the endolymphatic sac is capable of appropriately trapping macromolecule, KLH antigen (molecular weight: about 400 KDa), and removing antigens quickly from the inner ear.     

Growth control of embryonic stem cells injected into mouse uterus on fifth day of pregnancy

Previous studies have shown that embryonic stem cells (ES) may participate in normal embryonic development when they are injected into the blastocyst. In contrast, ES cells develop into tumors if injected in ectopic sites in adult mice. In this study we injected ES-D3 cells, with the LacZ gene incorporated, into 5-day pregnant mouse uteri, into pregnant unilaterally salpingectomized uteri, into pseudopregnant uteri and into non-pregnant uteri. X-gal staining enabled us to identify injected ES cells on the 7th, 9th, 10th, 12th and 15th days post-injection. In pregnant decidua, the ES cells were located initially in the mesometrial decidua and later distributed in the basal and capsular decidua and in the endodermic layer of the visceral yolk sac. In pregnant, unilaterally salpingectomized mouse uteri, ES cells were mainly located in the uterine lumen and tumors were not observed in either case. In contrast, ES cells injected into pseudopregnant uteri often developed into tumors and those injected into non-pregnant uteri always developed into teratocarcinomas. We conclude that the pregnant-uterine microenvironment may participate in the control of ES cell growth.     

Retention of functional characteristics by bovine oviduct and uterine epithelia in vitro

The composition of fluids within the bovine oviduct and uterine lumen, important in fertilisation and early embryonic development, is ultimately determined by the transport properties of the epithelial cells which line the lumen. A preparation has therefore been devised to study the role of these cells in oviduct and uterine fluid formation. Pure preparations of epithelial cells, as judged immunocytochemically, were isolated by enzyme digestion, and grown on collagen filters in primary culture. The cells re-establish intercellular junctions to form a confluent epithelial layer. Serial samples from the apical and basal media were analysed for K+, Na+, Ca2+, glucose and lactate. Bovine oviduct epithelial cells maintained gradients of K+ and Ca2+ (apical > basal) for up to 14 days after confluence, while bovine uterine epithelial cells maintained apical > basal gradients of K+. Both types of epithelium exhibited a small transepithelial electrical potential difference and a higher uptake of glucose and production of lactate in the basal, as opposed to apical medium. There were no consistent differences in any of these parameters with the stage of the oestrous cycle at which the cells were removed. The data indicate that bovine oviduct and uterine epithelia may be isolated and grown as polarised layers in primary culture. The preparations will now enable the mechanisms underlying the secretion of ions and non-electrolytes to be determined.     

Isolation, cell culture, and characterization of oviduct epithelial cells of the cow

This report describes an easy method of isolation and cell culture of the epithelial cells of cow oviduct. Incubation of cow oviduct with 0.1 mg/ml collagenase in the lumen for 90 minutes helped to dislodge large numbers of ciliated and secretory epithelial cells. The isolated cells, when seeded on plastic, proliferated very quickly and became confluent in 8-10 days in 35 mm Petri dishes. The isolated ciliated cells which attached to the plastic dish lost their cilia after 4-5 days in culture. The cultured epithelial cells were keretin positive. The isolated bovine oviduct epithelial cells, when cultured on plastic precoated with 10 mg/ml matrigel, organized themselves into hollow tubes or spheres with microvilli directed towards the lumen. The epithelial cells seeded on 2 mg/ml matrigel became subconfluent in 15-20 days after seeding. The histoarchitecture of the secretory cells growing in vitro on matrigel resembled that of intact oviduct secretory epithelial cells. Occasional ciliated cells containing large number of mitochondria were observed in the monolayer cultured on 2 mg/ml matrigel substratum but possessed few cilia. The oviduct epithelial cells cultured on 2 mg/ml matrigel incorporated 35S-methionine linearly into protein up to 8 hours in the presence of estradiol or progesterone. The fluorograph of the newly synthesized proteins indicated the presence of an additional 60 kd protein in the cell extract of epithelial cells incubated with estradiol.     

Metabolic disorder of otoconia after streptomycin intoxication

Little is known about the origin or the metabolism of otoconia. Streptomycin sulfate was found to cause a decrease in their number on the otolithic membrane of the utricle and saccule in guinea pigs. The remaining otoconia on the otolithic membrane varied in shape and size and giant otoconia with multilayered arrangement were observed by means of a scanning electron microscope. These otoconia contained the normal amount of calcium in the form of standard calcium calcite crystal. The lost otoconia were found attached to the surface of some vestibular dark cells. Otoconia in this new position were irregular, shrunken or fragmented. Their calcium content, measured with an X-ray micro-analyzer, was variably diminished. The dark cells appeared to be actively engaged in absorption of calcium ions, from the attached otoconia. The dark cell is considered to be a receptacle for the disposal of otoconia.     

Aspects on endolymphatic sac morphology and function

Morphological evidence indicate that the main function of the endolymphatic sac is to act as a reabsorptive and defensive mechanism for the inner ear. This activity is markedly enhanced in labyrinthine trauma, such as injection of foreign particles into the labyrinth, blocking of the endolymphatic duct, and cryosurgical destruction of vestibular sensory epithelia. Light and dark epithelial cells of the intermediate portion of the sac are capable of reabsorbing endolymph and digesting cellular debris respectively. The extensive capillary network surrounding the endolymphatic sac exhibits endothelial characteristics suggestive of active fluid transport. The "dynamic-flow theory" of endolymph circulation suggests that a radial-flow should be considered for energy metabolism and ion exchange around the sensory cell regions whereas a longitudinal-flow should be considered for reabsorption of endolymph and disposal of high molecular waist products and debris by the endolymphatic sac. The earlier concepts of endolymph circulation thus need not any longer be considered conflicting.     

Breast-feeding and drug exposure

Whirling disease caused by Myxobolus cerebralis has become the most widely known disease of salmonids in the 1990s. In the last 5 years we have studied many aspects regarding the host-pathogen relationship of this parasite. The parasite's histozoic development causes significant damage to cartilage and induces CNS symptoms by pressure on the brain and spinal cord. Myxobolus cerebralis has a two-host life-cycle involving a salmonid fish and a tubificid oligochaete. Two different stages of sporogony occur, one in each host. Early developmental stages in the fish can be found multiplying in the epidermis and peripheral and central nervous systems. The presporogenic stages then migrate to vertebral and cranial cartilages, where the first sporogonic phase occurs. Mature M. cerebralis spores found in fish cartilage are infectious for T. tubifex when ingested by the oligochaete after destruction of the infected fish. In the gut lumen of the tubificid, the spores extrude their polar capsules and attach to the gut epithelium by polar filaments. The shell valves then open along the suture line and the sporoplasm penetrates between the gut epithelial cells. The binucleate sporoplasm multiplies by schizogony, producing many one-cell stages which begin gamogonic development. As a result of the multiplication process, the intercellular space of the epithelial cells in more than 10 neighbouring worm segments may become infected. At this time (60-90 days p.i.), pansporocysts with eight zygotes start the sporogonic phase. The final stage of this development is a pansporocyst containing eight folded triactinomyxon spores. Shortly afterwards, the spores are liberated into the gut lumen. The spores reach the water either by egestion or following the death of the infected tubificids. Infected tubificids can release triactinomyxons for at least 1 year. The ultrastructure of all four phases, schizogony, gametogony, gametogamy and sporogony, is demonstrated and discussed.     

The use of Zn-desferrioxamine for radioprotection in mice, tissue culture, and isolated DNA

We previously reported that nitric oxide (NO) production in the unipolar brush (UB) cells is involved in vestibular compensation [T. Kitahara, N. Takeda, P.C. Emson, T. Kubo, H. Kiyama, Changes in nitric oxide synthase-like immunoreactivities in unipolar brush cells in the rat cerebellar flocculus after unilateral labyrinthectomy, Brain Res. 765 (1997) 1-6]. To further elucidate the role of NO-mediated signaling in flocculus after unilateral labyrinthectomy (UL), we examined UL-induced Fos expression, a marker of neural activity, in vestibular brainstem with continuous floccular infusions of Nomega-nitro-l-arginine methyl ester (l-NAME), an inhibitor of NO synthase (NOS). After UL with floccular l-NAME infusions, Fos expression appeared in bilateral medial vestibular (MVe) and prepositus hypoglossal (PrH) nuclei. After UL with floccular saline infusions, however, Fos expression was observed only in the ipsi-MVe and contra-PrH. Furthermore, it has been revealed that UL with l-NAME infusions caused more severe vestibulo-ocular disturbances than UL with saline infusions at the initial stage [Kitahara et al. Brain Res. 765 (1997) 1-6]. Therefore, it is suggested that UL with floccular l-NAME infusions activates the contra-MVe and ipsi-PrH neurons and causes more severe imbalance between intervestibular nuclear activities at the initial stage. NO-mediated signaling in flocculus could be a possible driving force of the flocculus-mediated inhibition on the contra-MVe and ipsi-PrH at the initial stage of vestibular compensation.     

cis-Elements in the 5''-region of the Oct-1 gene. Possibilities of autoregulation

The anti-diuretic hormone vasopressin (AVP) regulates water excretion from the kidney by increasing the water permeability of the collecting duct. AVP binds to V2-receptors and induces the translocation of aquaporin-2 water channels (AQP-2) into the apical plasma membrane of principal cells. By this mechanism AVP controls water reabsorption in the kidney. The effects of AVP on the endolymphatic sac (ES) of the inner ear, which is thought to mediate reabsorption of endolymph, were investigated. Both the V2-receptor and the AQP-2 water channel were found to be expressed in the ES epithelium. In the ES AVP binds to receptors most probably of the V2-subtype. Application of AVP to organotypically cultured ES inhibits membrane turnover in ribosomal-rich cells of the ES epithelia, which is thought to mediate translocation of AQP-2 into the surface membrane. This suggests that AVP has contrasting effects in the inner ear and kidney, which may be physiologically useful for maintaining endolymphatic pressure during severe hypovolemia. Animal experiments show that AVP causes endolymphatic hydrops after systemic application to guinea-pigs, which suggests a causal role for the increased AVP levels found in humans suffering from Ménière's disease.     

Field emission SEM, conventional TEM and HVTEM study of submandibular gland in prenatal and postnatal aging mouse

The development of acinar and ductal cells of the mouse submandibular gland was studied using field emission SEM, conventional TEM and HVTEM methods. The specimens, at 15 and 18 days of gestation and 1, 3, 7, 14, 21, 30, 90 and 180 postnatal days were fixed in 2.5% glutaraldehyde solution in 0.1 M sodium phosphate buffer (pH 7.3). At 15 and 18 days of gestation, the structure of mouse submandibular gland contains acinar and ductal cells in proliferation. The cytoplasmic organelles such as mitochondria, granular endoplasmic reticulum and Golgi apparatuses are scattered in the cytoplasm. At 18 prenatal days only several acinar cells present immature secretory granules in the apical portion. In this stage the acinar and ductal cells are enveloped by bundles of fine collagen fibrils disposed in several directions. There are also numerous capillaries located closely to the acinar cell membranes. In the aging stages of 1, 3, 7, 14, 21, and 30 postnatal days, the histo-differentiation of acinar, intercalated and ductal cell components are observed. At newborn day one the cytoplasmic organelles start to place themselves around the nucleus. Several immature secretory granules are observed at day one, however, they increase in the aging days. At postnatal day 30, the cytoplasms of acinar and ductal cells are filled with a large number of secretory granules of different sizes. The stacks of granular endoplasmic reticulum and Golgi apparatus and some vesicles and free ribosomes are noted. The intercellular membranes are attached by desmosomes and cytoplasmic interdigitations. The luminal surface shows several small projections of microvilli. An electron-dense line of basement membranes followed by fine collagen fibrils are recognized. Delicate capillaries are found in the outer surface of acinar cells. At postnatal day 90 and 180 the acinar, intercalated and striated ductal cells reveal numerous secretory granules in the apical portion. The acinar cells showed basal nuclei and the parallel arrangement of granular endoplasmic reticulum. The mitochondria are located at the base of ductal cells showing a typical pattern of cristae. In these stages the intercellular digitations of cytoplasmic protrusions and desmosomes are also noted. The cytoplasm of myoepithelial cells are seen along the cell membranes. The spongy-like structures constituting the basement membrane are followed by bundles of fine collagen fibers.     

Ultrastructure of the digestive system of adult Sanguinicola inermis

The alimentary tract of adult Sanguinicola inermis Plehn, 1905 (Digenea: Sanguinicolidae) was studied by transmission electron microscopy. A highly developed muscular region, likely to be a modified sucker, is present anteriorly to the oesophagus. The tegumental oesophagus, on the basis of the characteristics of the surface cytoplasm, is differentiated into anterior, median and posterior regions with the apical cytoplasm of the median oesophagus drawn into extracellular vesicles from which arise surface knobs. The oesophagus leads to a cellular intestine composed of a single layer of epithelial cells. The apical surface of the intestine is drawn into short luminal projections and the intestinal cells contain numerous organelles and secretory granules. No host cells or cell debris were evident within the alimentary tract, although the intestinal lumen was filled with electron-dense material.     

Shock controllability and opioid substrates of escape performance and nociception: Differential effects of peripherally and centrally acting naltrexone.

In 2 experiments with 104 male albino rats, Ss exposed to inescapable shock (IS) exhibited analgesia and a significant impairment of shock-escape learning in a shuttlebox situation 24 hrs later. In contrast, Ss exposed to escapable shock (ES) or to no shock (NS) displayed neither effect. Subcutaneous naltrexone HCl (10 mg/kg) significantly reduced the analgesia and completely eliminated the escape deficit in IS Ss, but it induced hyperalgesia and hampered escape performance in ES and NS Ss. The same dose of naltrexone methylbromide (quaternary naltrexone), which has low ability to cross the blood-brain barrier, had no effect on either the antinociception or the escape deficit produced by IS, although it also induced escape impairment and hyperalgesia in Ss preexposed to ES or to NS. Both the escape interference and the antinociceptive consequences of IS could be reduced partially by a much lower dose (1 mg/kg) of naltrexone, but 50 times this amount of quaternary naltrexone was still without effect. Results imply that the consequences of exposure to IS are mediated by activation of central opioid processes, whereas naltrexone-induced effects in ES and NS Ss may be peripherally mediated. (64 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Amylose-iodine complex. I. Sedimentation behavior

DNA-synthesizing cells in the gonads of the ascidian Styela clava were labeled with tritiated thymidine and detected with autoradiography. In the testis, spermatogonia and primary spermatocytes are labeled after 1 hr. Labeled spermatozoa occur in the lumen of the testis follicles after 10 days and in the sperm ducts after 20 days. In the ovary, only germ cells (oogonia and pre-leptotene primary oocytes) and follicle cells are labeled after 1 hr. By 60 days, oocytes with basophilic cytoplasm (15-65 mu in diameter) are labeled; test cells embedded in larger eosinophilic oocytes (150 mu in diameter) are also labeled. Germ cells give rise to both oocytes and follicle cells. Through continued cell division, follicle cells give rise to test cells.     

Optimal versus maximal safety of the blood transfusion chain in The Netherlands; results of a conference. College for Blood Transfusion of the Dutch Red Cross

The distribution of major components of the basement membrane, such as type IV collagen, laminin, and heparan sulfate proteoglycan (HSPG), was investigated in the rat cochlear duct. Immunofluorescence demonstrated that type IV collagen, laminin and HSPG were distributed along capillaries in the cochlear duct, including the stria vascularis, spiral ligament, spiral prominence and spiral limbus. Additionally, type IV collagen, laminin and HSPG were found to be distributed from the basement membrane of Reissner's membrane to that of the spiral prominence in a linear pattern. The scala media was surrounded by these basement membrane components, demarcating endolymph from perilymph, along epithelial cells except at the stria vascularis. These findings suggest that type IV collagen, laminin and HSPG create the anatomical separation between endolymph and perilymph, thus indicating that they may be involved in the regulation of fluid transport between the endolymph and perilymph.     

Nasopharyngeal carriage of community-acquired, antibiotic-resistant Streptococcus pneumoniae in a Zambian paediatric population

The present study was conducted to examine the response of amoeboid microglial cells in the postnatal rat brain to colchicine administration. One-day-old postnatal rats were given intraperitoneal injections of colchicine and sacrificed at 7, 14 and 21 days of age. In rats killed at 7 days age, the number of OX-42, OX-18 and ED1 positive amoeboid microglial cells was considerably reduced when compared with the control rats. At 14 and 21 days, the number of cells immunoreactive with the above antibodies was comparable to that of the control rats. The intensity of the immunoreaction with the various antibodies was also comparable in colchicine injected and control rats. When rhodamine isothiocyanate (RhIC) was administered, amoeboid microglial cells emitted a bright fluorescence in control rats as well as in colchicine-injected rats, although in the latter, the number of RhIC labelled cells was considerably reduced. With the antibody bromodeoxyuridine a large number of stained cells were observed in the control rats. On the other hand, occasional labelled cells were recognized in colchicine-injected rats. Apoptotic amoeboid microglial cells were observed in 4-day-old colchicine-injected rats. At the electron microscopic level, amoeboid microglial cells in colchicine-injected rats killed at 7 days of age showed a large number of phagosomes in their cytoplasm compared with the corresponding control rats. At 14 and 21 days, in colchicine-injected and control rats, amoeboid microglial cells did not display any noticeable differences. It is concluded from the present study that colchicine suppresses the number of amoeboid microglial cells, and that this may be attributed to the antimitotic effect of the drug as well as apoptosis induced by it; the phagocytic activity, however, was not affected. The cells returned to their normal population and morphological features once the drug was discontinued, indicating the reversible nature of the drug effect.     

Ontogeny of alpha-crystallin subunits in the lens of human and rat embryos

The distribution of alpha A- and alpha B-crystallin in the developing lens of human (Carnegie stages 13 to 23) and rat embryos (embryonic days E11 to 18) was examined immunohistochemically. In a human embryo at stage 13, the lens placode was already immunoreactive to alpha B-crystallin, but not to alpha A-crystallin. At stage 15, the lens vesicle was intensely immunoreactive both to alpha A- and alpha B-crystallin. From stages 16 to 23, the lens epithelial cells and fiber cells were immunoreactive to alpha A- and alpha B-crystallin. In rat embryos, alpha A-crystallin appeared in the lens pit at E12, and alpha B-crystallin appeared in the elongating lens fiber cells at E14. From E15 to E18, the lens epithelial cells and fiber cells were immunoreactive to alpha A-crystallin. The lens fiber cells were also immunoreactive to alpha B-crystallin, but the epithelial cells were not. These findings suggest that alpha B-crystallin appears earlier than alpha A-crystallin in the human lens, but at a later period than alpha A-crystallin in the rat lens. alpha B-Crystallin was not detected in the epithelial cells of the rat lens, but was persistently present in the epithelial cells of the human lens.