bluuebunny/crossref_metadata_2025 huggingface dataset:
Differentiation of eccrine poroma cells to cytokeratin 1 ‐ and 10‐expressing cells, the intermediate layer cells of eccrine sweat duct, in the tumor cell nests
Authors: Ban Masanori , Yoneda Kazufumi , Kitajima Yasuo
Published: April 2006

It has been shown that an intermediate cell layer exists between a luminal cell layer and a peripheral cell layer in human eccrine sweat ducts by immunohistochemistry using anti‐keratin antibodies 34βB4 and DE‐K10. These antibodies react to cytokeratin 1 and 10 respectively, and stain the intermediate cells specifically, but not luminal cells nor peripheral cells. Cytokeratin 1 and 10 are considered to appear as a differentiated keratin in the terminal process of epidermal keratinization. We examined 5 cases of eccrine poroma with 34βB4 and DE‐K10. Various numbers of the poroid cells reacted to these anti‐keratin antibodies in 4 cases. Some positive cells were observed around the cuticular cells in two of them. The present study demonstrated that terminal differentiation in terms of keratinization can occur in eccrine poromas, and that the 34βB4‐ and DE‐K10‐positive cells around the cuticular cells differentiate toward the intermediate cells in cytokeratin expression profile and location.
B Cell Activation
Authors: Waldmann Herman , Munro Alan
Published: April 2006

We consider that 2 'signals’are essential for B cell activation. 'Signal 1’is a consequence of appropriate latticing of surface immunoglobulin receptors. 'Signal 2’can be mediated by a variety of agents. Signal 1 alone (i.e. surface Ig aggregation) leads to a state of B cell tolerance. Appropriate levels of signal 1 and signal 2 lead to immune induction. Inappropriate combinations of either signal such that one is in‘excess’can direct B cells towards a state of tolerance.

T cells are felt to fulfil two roles, (a) They release antigen specific molecules capable of creating a lattice of antigenic determinants on a B cell surface, (b) They are responsible in interacting with macrophages for the production of NSF or Signal 2. (c) The B cell Ig‐antigen‐T cell receptor complex can serve to localise the effects of NSF to the region of the antigen specific B cell, and thus provide a safeguard against autoallergy.

Thymus independent antigens are capable of providing both types of signal.
Internal Images of Rabbit Immunoglobulin Allotopes
Authors: Cazenave Pierre‐Andre , Roland Jacques
Published: April 2006

L'homocorps, un ensemble de molécules nommé par Jerne “l'image interne”, ressemble à l'épitope non pas comme un moule ressemble à son empreinte, mats comme une empreinte ressemble à une autre empreinte issue du même moule.
From an Antigen‐Centered, Clonal Perspective of Immune Responses to an Organism‐Centered, Network Perspective of Autonomous Activity in a Self‐Referential Immune System
Authors: Coutinho A. , Forni L. , Holmberg D. , Ivars F. , Vaz N.
Published: April 2006

O que vemos, não e’o que vemos, senão o que somos1
Host MHC class I gene control of NK‐cell specificity in the mouse
Authors: Höglund Petter , Sundbäck Jonas , Olsson‐Alheim Mats Y. , Johansson Maria , Salcedo Margarita , Öhién Claes , Ljunggren Hans‐Gustaf , Sentman Charles L. , Kärre Klas
Published: April 2006

Summary: The missing self model predicts chat NK cells adapt somatically to the type as well as levels of MHC class I products expressed by their host, Transgenic and gene knock‐out mice have provided conclusive evidence chat MHC class I genes control specificity and tolerance of NK cells. The article describes this control and discusses the POSSIBLE Mechanisms behind it. starting from a genetic model to study how natural resistance to tumors is influenced by MHC class I expression in the host as well as in the target cells. Data on host gene regulation of NK‐cell functional specificity as well as Lγ49 receptor expression are reviewed, leading up to the central question: how does the system develop and maintain “useful” NK cells, while avoiding “harmful” and “useless” ones? The available data can be fitted with in each of two mutually non‐exclusive models: cellular adaptation and clonal selection. Recent studies supporting cellular adaptation bring the focus on different possibilities within this general mechanism, such as energy, receptor calibration and, most importantly, whether the specificity of each NK cell is permanently fixed or subject to continuous regulation.
Specificity, tolerance and developmental regulation of natural killer cells defined by expression of class I‐specific Ly49 receptors
Authors: Raulet David H. , Held Werner , Correa Isabel , Dorfman Jeffrey R. , Wu Ming‐Fan , Corral Laura
Published: April 2006

Summary: Natural killer cells in the mouse express class 1 MHC‐specific inhibitory receptors of the Ly49 protein family. The receptors mediate inhibition of the lysis of tumor cells and normal cells, and mediate the specificity of bone‐marrow graft rejection by NK cells in vivo. The function of these receptors may be to confer upon NK cells the capacity to distinguish normal self cells from cells that have down‐regulated expression of some or all self‐class I molecules, Ly49 receptors discriminate between different class I molecules, and are distributed in expression to overlapping subsets of NK cells. The receptors appear to interact with class I‐MHC residues and associated N‐glycans, with little or no discrimination of the class I‐ bound peptide. The Ly49 receptor repertoire may be initially generated by a stochastic process that distributes receptors randomly to I different cells and treats the two alleles of a given Ly49 gene independently. However, class I‐MHC‐dependent “education” processes shape the functional repertoire. The education processes silence potentially auto‐aggressive NK cells, probably by ensuring that each NK cell expresses at least one self‐specific Ly49 receptor. In addition, NK cell clones that express multiple self‐specific Ly49 receptors are disfavored by the education processes, perhaps to confer greater discrimination on to individual NK cells.
Specificity and function of immunoglobulin superfamily NK cell inhibitory and stimulatory receptors
Authors: Colonna Marco
Published: April 2006

Summary: Human NK cells express clonally distributed receptors specific for HLA‐A, ‐B and ‐C molecules. These receptors belong to the immunoglobulin superfamily and can be functionally distinguished as inhibitory or stimulatory Inhibitory receptors block NK‐cell‐mediated cytotoxicity upon binding to HLA class I ligands. This function is mediated by phosphorylation of cytoplasmic tyrosines, which recruit the protein tyrosine phosphatase SHP‐1. Stimulatory receptors also bind HLA class I, lack cytoplasmic tyrosine‐based motifs, and trigger NK cytotoxicity and proliferation. Both types of receptor are characterized by a limited diversity allowing for recognition of distinct class I supertypic epitopes. This limited diversity is counterbalanced by the expression of different combinations ill inhibitory and stimulatory receptors with self and/or non‐self HLA class I specificities on distinct NK cell clones. This peculiar strategy allows NK cells to detect loss of MHC class I molecules on autologous transformed and virally infected cells with maximal sensitivity.
Transduction of cytotoxic signals in natural killer cells: a general model of fine tuning between activatory and inhibitory pathways in lymphocytes
Authors: Renard Valéry , Cambiaggi Anna , Vély Frederic , Bléry Mathieu , Olcese Lucia , Olivero Sylvain , Bouchet Magali , Vivier Eric
Published: April 2006

Summary: NK‐cells axe large granular lymphocytes, which are capable of exerting two major types of effector function, cell cytotoxicity and lymphokine secretion. NK ‐cells can exert cell cytotoxicity in one of two ways. First, NK‐cells are able to recognize and to induce the lysis of antibody‐coated target ceils during antibody‐dependent cell cytotoxicity (ADCC). Second, during natural cytotoxicity NK cells are also able to recoginze to induce the lysis of a variety of target cell, including primarily virus‐infected cells as well as tumor cells. Recently, a novel mechanism has been elucidated which controls NK‐cell‐activation programs and which is based on the cell surface expression of killer‐cell inhibitory receptors (KIR). We will review here the molecular dissection of this inhibitory signalling pathway which utilizes immunoreceptor tyrosine‐based inhibition motifs (ITIM) expressed in KIR intracytoplasmic domain. We will also show that this strategy used by NK‐cells to regulate their effector functions a general decision mechanism which exists not only in T‐ and B‐lymphocytes, but also in a variety of other hematopoietic cells.
Use of adoptive transfer of T‐cell antigen‐receptor‐transgenic T cells for the study of T‐cell activation in vivo
Authors: Pape Kathryn A. , Kearney Elizabeth R. , Khoruts Alexander , Mondino Anna , Merica Rebecca , Chen Zong‐Ming , Ingulli Elizabeth , White Jennifer , Johnson Julia G. , Jenkins Marc K.
Published: April 2006

Summary: Adoptive transfer of TCR‐transgenic T cells uniformly expressing an identifiable TCR of known peptide/MHC specificity can be used to monitor the in vivo behavior of antigen‐specific T cells. We have used this system to show that naive T cells are initially activated within the T‐cell zones of secondary lymphoid tissue to prohferate in a B7‐dependent manner. If adjuvants or inflammatory cytokines are present during this period, enhanced numbers of T cells accumulate, migrate into B‐cell‐rich follicles, and acquire the capacity to produce IFN‐7 and help B cells produce IgG2a. If inflammation is absent, most of the initially activated antigen‐specific T cells disappear without entering the follicles and the survivors are poor producers of IL‐2 and IFN‐γ Our results indicate that inflammatory mediators play a key role in regulating the anatomic location, clonal expansion, survival and lymphokine production potential of antigen‐stimulated T cells in vivo.
Factors controlling the turnover of T memory cells
Authors: Sprent Jonathan , Tough David F. , Sun Siquan
Published: April 2006

Summary: Most of the T cells participating in the primary immune response are rapidly eliminated, but small numbers of these cells survive and differentiate into long‐lived memory cells. Information on the life history of memory cells can be obtained by studying the component of memory‐phenotype T cells found in normal animals; these cells are presumed to represent memory cells specific for various environmental antigens. For CD8+ cells, in vivo exposure to viruses and certain other infectious agents causes a large proportion of memory‐phenotype (CD44hi) cells to enter the cell cycle. In this situation, stimulation of CD44hi CD8+ cells does not seem to require T‐cell receptor ligation and appears to reflect release of various cytokines, especially type I interferon. The capacity of infectious agents to induce non‐antigen‐specific stimulation of T cells may play a role in boosting the survival of memory cells and perhaps also in providing an adjuvant function during the primary response.
The physiology of murine germinal center reactions
Authors: Kosco‐Vilbois Marie H. , Bonnefoy Jean‐Yves , Chvatchko Yolande
Published: April 2006

Summary: Germinal center responses are the mechanism that the immune system uses normally to generate high affinity antigen‐specific B‐cell receptors and secreted immunoglobulins. Genetically altered mice have provided powerful toots for dissecting the physiology of these germinal center responses. In this review, we have attempted to summarize information from various sources and interpret the new observations based ON what was previously known. A section is included to review the basic anatomy of the relevant slim lures in lymph node and spleen. A summary of the mutant mice producing a phenotype where germinal center responses are altered is also furnished. This review is aimed at providing useful information to those working in this field as well as those wishing to understand more about in vivo immunology.
Lymphotoxin‐α‐deficient and TNF receptor‐I‐deficient mice define developmental and functional characteristics of germinal centers
Authors: Matsumoto Mitsuru , Fu Yang‐Xin , Molina Hector , Chaplin David D.
Published: April 2006

Summary: Mice deficient in LTa (LTα‐/‐) lack lymph nodes and Peyer's patches. This action of LTa in lymph node organogenesis appears to be mediated by the membrane form of LT using a mechanism independent of TNF receptor I (TNFR‐I) or II (TNFR‐II). In contrast, normal Peyer's patch development appears to require both LTa and TNFR‐I, with TNFR‐I‐/‐ mice showing hypoplastic Peyer's patch structures. LTα‐/‐ mice also fail to support the normal segregation of T‐cell and B‐cell zones within the splenic white ptilp. Again, this occurs via a mechanism independent of TNFR‐I or TNFR‐II. Additionally, follicular dendritic cell (FDC) dusters or germinal centers fail to develop in the spleen of LTα‐/‐ animals. Mice defi‐cient in either TNFα or TNFR‐I also fail to develop splenic FDC dusters and germinal centers, indicating that signaling by both LTα and TNFα is required for development of these speciahzed lymphoid tissue structures. Finally, the splenic white pulp areas in LTα‐/‐ mice lack the marginal zone of monoclonal antibody MOMA‐1‐staining metallophilic macrophages, whereas TNFR‐I‐deficient mice have preserved MOMA‐1 staining. Thus, certain actions of LTa to regulate spleen white pulp architecture are medi‐ated by receptors other than TNFR‐I, most likely by the LTβR or a closely related receptor. We tested whether germinal centers are essential for mat‐uration of T‐cell‐dependent antibody responses. When LTα‐/‐ mice were immunized with low doses of NP‐ovalbumin (NP‐OVA) adsorbed to alum, there was dramatically impaired production of high afTmity anti‐NP IgG; however, after immunization with high doses of NP‐OVA adsorbed to alum, LTα‐/‐ mice mounted a high affinity NF‐specific serum IgG response similar to wild‐type mice, all in the absence of germinal centers or clus‐tered FDC. Thus, although germinal centers enhance the processes required for maturation of the humoral immune response, the mecha‐nisms responsible for affinity maitiration are not absolutely dependent on the presence of germinal centers.
Follicular dendritic cells (FDC) in retroviral infection: host/pathogen perspectives
Authors: Burton Gergory F. , Masuda Akihiro , Heath Sonya L. , Smith Beverly A. , Tew John G. , Szakal Andras K.
Published: April 2006

Summary: Follicular dendritic cells (FDC) are found in the follicles of virtually all secondary lymphoid tissues. In health, these cells trap and retain antigens (Ag) in the form of immune complexes and preserve them for months in their native conformation. FDC thus serve as a long‐term repository of extracellular Ag important for induction and maintenance of memory responses. In retroviral infection. FDC trap and retain large numbers of retroviral particles with profound effects on FDC. FDC‐trapped retrovirus induces follicular hyperplasia, and conventional Ag trapped prior to infection are lost and new Ag cannot be trapped. Concomitantly, antibody‐forming cells (AFC) specific for Ag lost from FDC decrease follow I by loss of specific serum antibody (Ab). Eventually, FDC die and follicular lysis occurs. From the pathogen perspective, binding to FDC is remarkably beneficial, bringing together virus and activated target cells that are highly susceptible to infection. Furthermore, FDC permit HIV to infect surrounding cells even in the presence of a vast excess of neutralizing Ab. Preliminary data suggest that FDC maintain virus infectivity ‐ even when the virus cannot replicate. Thus retrovirus infection monopolizes FDC networks, thereby transforming the FDC Ag repository into a highly infectious retroviral reservoir.
Antigen localisation regulates immune responses in a dose‐ and time‐dependent fashion: a geographical view of immune reactivity
Authors: Zinkernagel Rolf M. , Ehl Stephan , Aichele Peter , Oehen Stephan , Kündig Thomas , Hengartner Hans
Published: April 2006

Summary: This review summarises experimental evidence to illustrate that induction of immune reactivity depends upon antigen reaching and being available in lymphoid organs in a dose‐ and time‐dependent manner. If antigen reaches lymph organs in a localised staggered manner and with a concentration gradient, a response is induced in the draining lymph node. Antigen‐presenting cells are of critical importance to transport antigen from the periphery to local organised lymphoid tissue. If antigen is all over the lymphoid system, then it deletes all specific cells in the thymus or induces them within a few days: because of their limited life‐span they then die off, leaving the repertoire depleted of this specificity. If antigen does not reach lymphoid organs it is ignored by immune cells. Once a response is induced, activated but not resting T cells will reach antigen outside lymphoid organs, whereas activated B cells differentiate into plasma cells in an inducing environment, mostly in lymphoid tissue including bone marrow, but also in chronic lymphoid‐like infiltrations in peripheral organs. In immunopathology (when the infectious agent is known) or in autoimmunity (when the triggering infectious agent is not known or not recognised) lymphoid tissue may become organised close to the antigen (e.g. in organ‐specific autoimmune diseases) and may thereby maintain an autoantigen‐driven disease‐causing immune response for a long time, The notion that naive T cells get induced or silenced in the periphery may be questioned because induction can only occur in lymphoid organs providing anatomical structures where critical cell‐cell interactions are properly guided and where, therefore, cells are likely to meet sufficiently frequently and in a critical milieu. Since overall immune reactivity critically depends upon the localisation of antigens in a dose‐ and time‐dependent manner, it seems more likely ‐ but this remains to be shown ‐ that activated T cells may get exhausted in non‐lymphoid peripheral tissues, whereas they are usually maintained in lymphoid organs. The critical role of antigen in regulating immune responses also has relevance for our understanding of immunological defence against epithelial and mesenchymal tumours, against many infectious diseases and for understanding autoimmunity and immunological memory. Collectively the data indicate that antigen, impendent upon localisation, dose and time, seems to be the simplest regulator of immune responses.
Attempted therapeutic immunization in a chimpanzee chronic HBV carrier with a high viral load
Authors: Shata Mohamed Tarek M. , Pfahler Wolfram , Brotman Betsy , Lee Dong‐Hun , Tricoche Nancy , Murthy Krishna , Prince Alfred M.
Published: May 2006

Background  We previously reported successful therapeutic immunization in a chimpanzee having a relatively low viral load, which was immunized with recombinant plasmid hepatitis B surface antigen (HBsAg) DNA and boosted with recombinant HBsAg encoding canarypox virus. In the present study, we attempted to confirm these findings in an animal with a high virus load.

Methods and Results  We tested three immunization strategies successively over a 3‐year period. In the first of these, we administered four monthly injections of DNA encoding HBsAg + PreS2 + hepatitis B core antigen (HBcAg) + DNA encoding interleukin (IL)‐12, (given 3 days later), and boosted with canarypox expressing all of the above HBV genes 6 months after initial immunization. No reduction in viral load was observed. In the second trial, we administered lamivudine for 8 weeks, and then began monthly DNA‐based immunization with plasmids expressing the above viral genes; however, viral loads rebounded 1 week after termination of lamivudine therapy. In a third trial, we continued lamivudine therapy for 30 weeks and immunized with vaccinia virus expressing the above viral genes 18 and 23 weeks after the start of lamivudine therapy. Again viral loads rebounded shortly after cessation of lamivudine treatment. Analysis of cell‐mediated immune responses, and their avidity, revealed that DNA‐based immunization produced the strongest enhancement of high avidity T‐cell responses, while recombinant vaccinia immunization during lamivudine therapy enhanced low avidity responses only. The strongest low and high avidity responses were directed to the middle surface antigen.

Conclusions  Three strategies for therapeutic immunization failed to control HBV viremia in a chronically infected chimpanzee with a high viral load.
Airsacculitis in fourteen juvenile southern Bornean orangutans (Pongo pygmaeus wurmbii)
Authors: Lawson Becki , Garriga Rosa , Galdikas Biruté M.F.
Published: May 2006

Background  Airsacculitis is a clinical condition which has been reported in a range of primates species, including orangutans.

Methods  This report describes the occurence and management of airsacculitis in fourteen juvenile Southern Bornean orangutans (Pongo pygmaeus wurmbii) that presented beween January 1st 1999 and January 31st 2001 at the Orangutan Care Center and Quarantine (OCC&Q), Kalimantan Tengah, Indonesia (S 2°43’ 49.2”; E 111°38’ 54.2”). Details of the signalment, clinical history, presenting clinical signs, clinicopathological findings and bacterial isolates in each case were reviewed.

Results  Cough, halitosis and nasal discharge were the most frequently observed clinical signs. A range of Gram‐negative bacteria were isolated from infected air sacs, including Pseudomonas sp., Enterobacter sp. and Klebsiella pneumoniae. A simple drainage and lavage technique was used in cases where surgical intervention was indicated, in combination with local and systemic antibiotic therapy.

Conclusions  The importance of early diagnosis, prompt management and antibiotic selection, based on bacterial culture and sensitivity profiles, is outlined.
Marmoset glutathione peroxidases: cDNA sequences, molecular evolution, and gene expression
Authors: Atanasova Srebrena , Von Ahsen Nicolas , Schlumbohm Christina , Wieland Eberhard , Oellerich Michael , Armstrong Victor
Published: May 2006

Abstract Background  Dysfunction of the cellular antioxidant system and accumulation of reactive oxygen species are involved in the pathophysiology of diseases such as cardiovascular disease, neurodegenerative disorders, tumors, male infertility and aging. Two gluthathione peroxidases play key roles in the cellular protection against oxidative damage. Glutathione peroxidase (GPx‐1) removes cytosolic hydroperoxides while phospholipid‐hydroperoxide glutathione peroxidase (GPx‐4) is a unique enzyme that reduces phospholipid peroxides in membranes.

Methods  We cloned and sequenced the full‐length cDNA for GPx‐1 (GenBank: AY966403) and GPx‐4 (GenBank: AY966404) from the common marmoset (Callithrix jacchus) in order to create a suitable model for studying human diseases related with oxidative stress.

Results  The cDNAs encode a 202 amino acid protein for GPx‐1 and a 197 amino acid protein for GPx‐4. Both proteins include selenocysteine (Sec, in Gpx‐1 at position 48; in GPx‐4 at position 73) and showed high homology (>90%) with other mammalian GPxs. The relative levels of mRNA expression for GPx‐1 and GPx‐4 were determined in different marmoset tissues by quantitative real‐time reverse transcriptase‐polymerase chain reaction using transcription elongation factor‐2 as a reference gene. GPx‐1 showed increased levels of expression in the liver, heart and kidney while the highest mRNA levels for GPx‐4 were detected in the testis, followed by the liver, lung, kidney and spinal cord.

Conclusions  These findings will be of value for studies designed to assess the role of glutathione peroxidases in non‐human primate models for a variety of diseases in which increased oxidative stress has been implicated.
Enzyme histochemical studies on the formation of hyalin bodies in the epithelium of odontogenic cysts
Authors: Morgan Peter , Heyden Guy
Published: April 2006

Abstract: Frozen sections of eight odontogenic cysts, including one keratocyst, were incubated to show the following enzyme activities: NADH2 diaphorase, NADPH2 diaphorase, glucose‐6‐phosphate dehydrogenase, acid phosphatase and leucinc aminopeptidase. The distribution of lipid was shown by the oil red 0 method. The activities of all three oxidative enzymes were strongest in epithelial cells bordering hyalin bodies and in basal cells in the epithelial lining. Hydrolytic enzyme activity was absent from all but the most superficial epithelial cells but was present in macrophages and, in lesser amounts, in granular material in the same sections. The granular material frequently contained lipid. The lack of hydrolytic enzyme activity in bordering epithelial cells is inconsistent with the theory that hyalin bodies form from degenerating blood vessels. High aerobic oxidative enzyme activity in the same cells also conflicts with the concept that the bodies are a keratinous product. The findings lend support to the theory that hyalin bodies are an epithelial secretion.
The relation of the clinical picture to the histopathology of snuff dipper's lesions in a Swedish population
Authors: Axéll T. , Mörnstad H. , Sundström B.
Published: April 2006

The relation of the clinical picture of snuff dipper's lesions to the histopathological appearance was studied in 114 male dippers aged 20–88 years.

Histological study revealed increased epithelial thickness, a vacuolated surface layer with wavelike, eosinophilic spikes directed toward the surface having a narrow, eosinophilic band as a demarcation toward the prickle cell layer, acanthosis, and a slight inflammatory reaction. Thirteen cases showed an increased number of eosinophilic granulocytes, and nine cases contained amorphous, weakly eosinophilic areas in the connective tissue papillae. No epithelial dysplasia was observed.

Increased epithelial thickness, especially the presence of a vacuolated surface layer, was the only histologic feature that could be correlated with the severity of clinical appearance of the lesions. Deeply located changes, like inflammation and amorphous areas, however, were not reflected in the clinical grading of the lesions.
Long‐term organ culture of hamster cheek pouch mucosa
Authors: Mock David , Main James H. P.
Published: April 2006

Explants of cheek pouch mucosa from 12‐ to 48‐hour‐old hamsters have been maintained in organ culture for up to 49 days with excellent preservation of tissue integrity and relationships. The technique uses gelatin sponge matrix in Leighton tubes with Eagle's Minimum Essential Medium (M.E.M.) supplemented with 10% calf serum and antibiotics.
Odontoblast metabolism in rats deficient in vitamin D and calcium II
Authors: Engström C. , Granström G. , Linde A.
Published: April 2006

Rats were fed a low calcium diet deficient in vitamin D for 14 days. Changes in alkaline phosphatase activities in odontoblasts dissected out from incisor teeth were studied biochemically. A strong increase in pNPP‐ase, PPi‐ase, total ATP‐degradation and Ca2+ ‐ATPase was observed in the deficient animals compared with animals fed a control diet.
An autoradiographic study of experimental odontogenic cyst formation in the mouse
Authors: Atkinson M. E.
Published: April 2006

Proliferative populations of cells within the epithelial lining of developing experimental odontogenic cysts were identified by labeling with 3H‐thymidine. Mouse molar teeth extracted from 10‐day‐old mice were transplanted subcutaneously and host animals were injected with 3H‐thymidine 1 h prior to sacrifice. The cysts which developed around the crown of the transplanted teeth were prepared for autoradiographical examination. Labeling indices were high initially but decreased rapidly as the cysts enlarged. The pattern of labeling, however, bore no resemblance to the labeling of the reduced enamel epithelium from which the cysts developed. It was concluded that labeling activity reflects only the state of development and activity of the cyst and not the origin of the cyst.
Glossal double fissures in pre‐ and post‐natal human specimens
Authors: Farman Allan G.
Published: April 2006

Glossal double fissures were found in a similar proportion of both pre‐ and postnatal tongue specmens. The condition was found in both sexes and in subjects of Negro, Caucasian and mixed ethnic origins. In cross‐section, the area bounded by the fissures varied from raised to flat or depressed. Histologic analysis suggested that the double fissure appearance was a reflection of the topography of the subjacent muscle bundles and that true fissuring, when present, was probably a secondary phenomenon akin to acquired plication.
Pulpal response to pyruvic acid
Authors: Relief D. H. , Austin J. C.
Published: April 2006

Abstract. Etching of enamel surfaces produces a marked increase in the bond strength of dental materials to tooth structure. The results of recent studies have indicated that pyruvic acid may be used in preference to phosphoric acid, because of its milder etching effect on enamel surfaces, without adversely affecting the bond strength. The pulpal responses elicited by 10 % pyruvic acid applied for 90 seconds to freshly prepared cavities in monkey teeth, were examined after 4, 14 and 42 days. The differences between some of the criteria used to evaluate the pulpal responses in acid‐treated and control teeth at the three postoperative time intervals were statistically significant. These results suggest that exposed dentin should be protected with a lining before etching adjacent enamel surfaces with 10 % pyruvic acid.
Histopathological and immunological aspects of tooth transplantation
Authors: Atkinson M. E.
Published: April 2006

Histopathological studies of teeth transplanted between genetically identical and dissimilar animals and to animals in which the immune response is suppressed or enhanced show that autografts and isogratts degenerate but then are repaired, whereas allografts show a bewildering array of changes from almost total destruction to total repair. Some explanations for the repair of teeth in an immunologically hostile environment are put forward.

The immunological aspects of tooth transplantation are also reviewed. Transplanted teeth stimulate an immune response from the host and are subject to the same rules of genetic relationship which apply to other tissues. Most components of the teeth are antigenic in isolation but only the pulp and periodontal ligament have so far been demonstrated to possess these properties in viro. Transplanted teeth also elicit antibody formation but the importance of antibodies in the rejection process is still disputed.

It is concluded that teeth are not immunologically privileged tissues but will elicit cell‐mediated responses from allogeneic hosts and are subject to the same invasive‐destructive lesions as a result. The peculiar observations of repair of allogeneic teeth and delayed immune responses can be explained by considering the histopathology of transplanted teeth and their capacity for repair.

Finally, the use of transplanted teeth to study odontogenesis and pathological entities such as odontogenic cysts and reparative dentin formation are briefly reviewed.
A new method of sterilization: the carbon dioxide laser
Authors: Adrian James C. , Gross Arthur
Published: April 2006

Abstract The use of the carbon dioxide (CO2) laser for sterilization of metal instruments was investigated. Scalpel blades contaminated with bacterial spores were exposed to the laser and subsequently cultured. Our results demonstrate that the CO2 laser effectively sterilizes metal Instruments.
Fine structure of cell types in an ameloblastoma
Authors: Kim S. K. , Nasjleti C. E. , Whatherbee L.
Published: April 2006

Abstract.An unusually large and old ameloblastoma, which revealed a diverse histological appearance, was studied by light and electron microscopy. In the tumor, the epithelial component formed several patterns in the collagenous stroma. The epithelial islands, consisting of tall columnar cells surrounding the inner core of stellate cells, mimicked the cells of the inner enamel epithelium and stellate reticulum, respectively, of the normal enamel organ. The ultrastructural appearances of the columnar cells, however, were only similar to those which are seen in undifferentiated preameloblasts. Areas of squamous metaplasia were present, and these squamous cells were structurally similar to the cells al the base of the oral epithelium. Some epithelial cells containing numerous lipid granules and mitochondria formed a network of cords. The connective tissue stroma was made up of fibroblast‐like cells which appear to be metabolically active. In addition, multinucleated giant cells were present in the connective tissue stroma near the epithelial component.
Pathways of inflammatory cellular exudate through radicular cyst epithelium: A light and scanning electron microscope study*
Authors: Cohen Mark A.
Published: April 2006

Abstract. A feature of radicular cyst histology is the observation that polymorphonuclear leucocytes infiltrate the epithelium whereas chronic inflammatory cells do not and accumulate in the sub‐epithelial connective tissue. Material for the study of this phenomenon consisted of radicular cysts fixed in formol saline. Observation under the SEM indicated that the lumenal surface of the radicular cyst is characterized by numerous interepithelial spaces through which polymorphonuclear cells reach the cyst cavity. The cells on the lumenal surface are associated with interepithelial spaces. Observations of the cut surface indicate that channels occur between epithelial cells through which the polymorphonuclear leucocytes migrate. The channels may also be a pathway for exudates from capillaries to reach the cyst cavity and provide a means for radicular cyst enlargement. Erosions of epithelial cells and features of necrosis of superficial cells were observed. Thus it appears that polymorphonuclear leucocytes migrate through definite channels between epithelial cells in the radicular cyst lining, the chemotactic stimulus being degeneration and breakdown of the superficial epithelial cells.
Stereological analysis of hamster cheek pouch epithelium after one application of DMBA or turpentine
Authors: Frankling C. D. , Craig G. T. , Scanlan S.
Published: April 2006

Abstract Both check pouches of two groups of live male hamsters were treated with one application of either 50′% turpentine in liquid paraffin (TLP50) or a 0.5% solution of dimethylbenz(α)anthracene in liquid paraffin (DMBA); animals were killed 48 h later. Five untreated animals served as controls. Mucosal specimens were removed from each pouch, fixed in formal‐acetic‐alcoliol and processed for light microscopy. Sections were cut at 4 μm and stained with haematoxylin and eosin. A systematic random sampling method was used to obtain sections for Stereological analysis. Grids for point and intersect counting were superimposed on the projection screen of an automatic sampling microscope. Results showed that the epithelial nuclear‐cytoplasmic ratio, nuclear density, nuclear diameter and surface area interface ratios were similar for the experimental groups and, with the exception of the last parameter, differed significantly from controls. The volume proportion of TLP5O‐treated epithelium was significantly larger than that of DMBA‐treated epithelium. Derived values for the average nuclear volume in both experimental groups were almost twice that of controls; the cytoplasmic volumes were more than doubled. At 48 h the epithelial response to a single application of TLP50 or DMBA was essentially similar except that TLP50 probably induced greater hyperplasia.
Fibronectin
Authors: Ruoslahti Erkki
Published: April 2006

Abstract The current knowledge of the structure, expression and functions of fibronectin is reviewed.

Fibronectin is a high molecular weight glycoprotein present in the blood, connective tissue and at cell surfaces. It is synthesized by many types of differentiated cells and is believed to be involved in the attachment of cells to the surrounding extracellular matrix. Fibronectin has affinity to the other main components of extracellular matrix, collagen and glycosaminoglycans. It also interacts with cell surfaces as shown by the fact that fibronectincollagen complexes, or fibronectin alone when insolubilized on a surface such as plastic, enhances the attachment of various types of cells to such surfaces.

It seems that fibronectin, through its binding to collagen and to the cell surface, forms a bridge between the cell and its surrounding matrix. Circulating fibronectin may participate in the formation of extracellular matrix in tissues. It may also function as a nonspecific opsonin designed to facilitate the uptake of tissue debris by phagocytic cells.

Studies aimed at elucidating the significance of fibronectin in physiological phenomena and in disease have only just begun. The abundance of fibronectin in basement membrane structures and the developmental changes observed in its expression lead one to believe that the attachment (or lack of it) of cells to fibronectin plays a significant role in morphogenetic events or in normal development. Malignantly transformed cells tend to lack cell‐associated fibronectin. The significance of the lack of surface fibronectin in transformed cells is a matter of some controversy, but if fibronectin is indeed the main mechanism that anchors cells to the extracellular matrix, disturbances of this mechanism could play an important role in malignancy and many other diseases.
Permeability of gingival sulcular epithelium in the development of scorbutic gingivitis
Authors: Alvares Olav , Siegel Ivens
Published: April 2006

Abstract Young adult nonhuman primates were initially fed an ascorbic‐acid free diet and, subsequently, a diet with a suboptimal level of the vitamin. Following approximately 12 weeks of this dietary regime, five of seven experimental animals developed scorbutic gingivitis. 2 to 3 weeks prior to this stage, the permeability of the gingival sulcular epithelium to 3Hinulin, but not to 14C‐butyric acid or 14C‐urea, had increased significantly (+86%, P < 0.01) in the experimental group as compared to ad libitum or pair‐fed controls. This defect in the intercellular permeability barrier of the sulcular epithelium could have contributed to the pathogenesis of scorbutic gingivitis.
Correlation of changes in capillary supply and epithelial dimensions in the hyperplastic buccal mucosa of zinc‐deficient rats
Authors: Meyer J. , Stohle M. R. , Stablein M. J.
Published: April 2006

Abstract Lengths of capillaries and epithelial dimensions were measured on tracings of sections of buccal mucosa stained for alkaline phosphatase from rats on a zinc‐deficient diet.

The zinc‐deficient animals showed the following increases over controls: length of capillaries, ×2.67; thickness of cell layer, ×1.47; thickness of keratin layer, ×2.82; basal layer length: surface length ratio, ×1.41. Lengthening of the basal layer and the capillaries showed high positive correlations with thickening of the cell layer. Lengthening of the capillaries exceeded the lengthening of the basal layer and the thickening of the epithelium but fell short of the increased anabolic performance of the epithelium as quantitated in previous investigations.
Transplacental induction of ameloblastoma in rat using ethylnitrosourea (ENU)
Authors: Pearl Gary S. , Takei Yoshio
Published: April 2006

Abstract We report the first instance of transplacental induction of an ameloblastoma using a nitrosourea compound. This model may be of use in the study of odontogenic tumors.
Amyloid in a pleomorphic adenoma of the parotid gland
Authors: Tadler Bernard
Published: April 2006

Abstract A case of cellular pleomorphic adenoma of the parotid gland was studied by electron microscopy. The tumor contained stromal masses of 8‐nm filaments that were identified as amyloid. None of the surrounding cells contained amyloid fibers
Variations in the nuclear‐cytoplasmic ratio during epithelial differentiation in experimental oral carcinogenesis
Authors: White F. H. , Gohari K.
Published: April 2006

Abstract An increased nuclear‐cyloplasmic ratio is one of the cytological features of epithelial alypia taken into account when the histopathologist subjectively assesses whether an epithelial lesion is likely to become malignant. The present work evaluates this ratio ultrastructurally in the DMBA‐treated hamster cheek pouch model with a view to assessing whether alterations of this feature represent a valid indicator of malignant transformation. Following DMBA treatment, lesions obtained were assigned to three defined histopathological categories, namely epithelial hyperplasia, epithelial dysplasia and squamous cell carcinoma. Untreated pouches served as controls. Electron micrographs were obtained of basal, spinous and granular layer cells from each of these categories and the N/C ratio was evaluated using stereological point counting techniques. The results indicated that progressive decreases in the ratio occurred in all pathological stages during differentiation (i.e., between basal and granular cells). During carcinogenesis there was a tendency for the ratios to decrease in each cell layer but significant differences were not detected between normal and premalignant lesions.
Comparison of the ultrastructure of a malignant tumor of the mandible containing giant cells with Paget's disease of bone
Authors: Mills B. G.
Published: April 2006

Abstract Distinction between lesions of the jaws containing giant cells can be difficult. This study reports the results of the study of the ultrastructure of 30 patients with Paget's disease in comparison with a patient diagnosed as having malignant giant cell tumor of the mandible. The ultrastructure of the malignant giant cell tumor of the mandible was found to contain nuclear inclusions morphologically identical with the 12–15 nm tubules characteristic of the nuclei of osteoclasts in Paget's disease of bone. No clinical or laboratory signs of Paget's disease were found in this patient. A search of the literature failed to produce reports of identical nuclear inclusions in soft tissue giant cell tumors, osteosarcomas, reparative granulomas containing giant cells or in osteitis fibrosa eystica. Such nuclear inclusions have been reported in benign giant cell tumors of bone, one other in malignant giant cell tumor and cases of polymyositis. These observations raise the question of a possible virus associated with the tumor since there arc recent reports of immunological evidence for the presence of a virus in Paget's disease, and viruses have been suspected in polymyositis.
Intraoral adenocarcinomas
Authors: Stene Torrjøkn , Koppang Hanna Strømme
Published: April 2006

Abstract Of 65 intraoral salivary gland tumors received by the Department of Pathology, Dental Faculty, University of Oslo between 1957 and 1979, 13 (20%) were diagnosed as adenocarcinomas. A study of available clinical data and histologic features indicates that these are slow‐growing neoplasms which metastasize late.
Changes in periodontal fibre organization in mature bone/tooth isografts in mice
Authors: Barrett A. P. , Reade P. C.
Published: April 2006

Mature mouse mandibular third molars together with their periodontal ligaments and alveolar bone were isografted to two heterotopic sites: the renal subcapsular site and the tibial shaft medulla. The pulps and periodontal ligaments of the grafts underwent cellular degeneration after Transplantation but demonstrated signs of revascularization and cellular repopulation 7 days after Transplantation. Grafts obtained at 28, 60 and 100 days after Transplantation demonstrated a significant decrease in the width of the periodontal ligament, a decrease in the number and organization of mature periodontal fibre bundles, the appearance of fibres arranged parallel with the root surface and a decrease in the thickness of surrounding alveolar bone. These regressive changes in the periodontal ligament were considered to be due primarily to the nonfunctional status of the teeth at the two heterotopic sites.
The presence and distribution of carcinoembryonic antigen in tumors of human minor salivary glands
Authors: McDicken I. W. , Scott John
Published: April 2006

Abstract Using an immunoperoxidase method we have demonstrated carcinoembryonic antigen (CEA) in more than half of a series of 62 tumors of minor salivary glands. CEA was present in both benign and malignant tumors. Its presence was related mainly to the formation of well differentiated ductal tissue in the neoplasms rather than to the histologic type of tumor. Although of only limited diagnostic value, the histologic presence of CEA in a particular tumor may indicate the possibility of postoperative monitoring of saliva and plasma, particularly where residual tumor, metastases or recurrences arc considered likely.
Snuff‐induced lesions of the oral mucosa – an experimental model in the rat
Authors: Hirsch Jan‐Michaél , Thilander Holger
Published: April 2006

An experimental model in the white rat has been developed in order to study the influence of snuff on oral mucosa. A test canal in the lower lip, with one orifice buccally to the incisors and one on the lip side, was created by surgical means. The connection between the canal and the oral cavity was made to ensure the presence of saliva in the canal so that physiological conditions resembling those of the oral cavity were obtained. The canal was filled with snuff morning and night 5 days a week. The mean value for the maximal retention time of the snuff was 6 h. The animals tolerated the dose and time of exposure without signs of severe toxic symptoms. Histological examination of the canals after 9 months of exposure to snuff showed a mildly to moderately hyperplastic epithelium with hyperorthokeratosis. Locally deep proliferations of epithelium with acanthotic rete pegs could be seen. In the stratum basale hyperplasia with disturbed polarity and hyper‐chromatic nuclei and single mitosis were noted.
Serum β2 microglobulin in oral malignancy and premalignancy
Authors: Scully Crispian
Published: April 2006

Scrum β2 microglobulin concentrations measured by radioimmunoassay in patients with oral squamous cell carcinoma, or with oral keratosis and epithelial dysplasia, were found to be significantly increased compared with age and sex matched controls.
Effects of zinc deficiency on rat parotid gland
Authors: Alvares Olav , Johnson Dorthea
Published: April 2006

Hitherto, the effect of zinc deficiency on the rat parotid gland was not known. Male rats were fed cither a low zinc diet (0.4–0.8 ppm Zn) or a zinc adequate diet (approximately 40 ppm Zn) for 35–42 days. The experimental animals exhibited retarded body growth, anorexia, loss of hair and decreases in plasma and hair zinc levels. In comparison to the ad libitum controls, the parotid glands of the pair‐fed group showed a decrease in cell number, but an increase in cell mass, protein and amykisc content. In the parotid glands of the experimental group, cell number was comparable to the pair‐fed group, but there was a decrease in cell mass and protein content as compared to the pair‐fed group. These findings suggest that zinc deficiency and its associated reduced food intake impair growth of the parotid gland and, further, that zinc deficiency per se appears to lead to a diminution in gland protein synthesis. It is proposed that a compromise in parotid gland function could be a contributory factor underlying the increased susceptibility to dental caries known to occur in zinc deficiency.