Comparison of rat mandible bone characteristics in F344 substrains, F344/Du and F344/N

The characteristics of the mandible bone were compared through DXA methods between two major substrains of F344 rats, F344/DuCrlCrlj and F344/NSlc at around 60 days of age. Since these two substrains are clearly different in survival and mandible morphology, some genetic differences are supposed to exist. In contrast to a previous microsatellite analysis, clear and significant differences were detected in the body and mandible weights, the mandible bone mineral contents (BMC), bone area (AREA), bone mineral density (BMD) and bone mineral ratio (BMR), between F344/DuCrlCrlj and F344/NSlc, with the mandible molar teeth intact in the bone. Thus, care is needed in the experimental use of these substrains, as results may differ between them. The newly proposed parameter, BMR, may especially contribute to the comparison of bone characteristics among species.

Overview of the lacrimal canaliculus in microscopic cross-section

Although many illustrations have been published seeking to explain the anatomy of the lacrimal canaliculus and its surroundings, to our knowledge, no micrograph showing the total length of the lacrimal canaliculus has ever been displayed. Here, we present a clear microscopic cross-section of the total length of an upper lacrimal canaliculus, except for the vertical part. A winding path was found in part of the canaliculus. The common canaliculus opened into the lacrimal sac almost perpendicularly and was covered by solid fibrous tissue. The transition between squamous cell epithelium and columnar epithelium did not always take place at the opening. There were superficial goblet cells, mucous secretory glands and intraluminal debris in the distal part of the canaliculus, including the common canaliculus, where the lining consisted of columnar epithelium. The clear overview of the structures presented here should be helpful in the treatment of the lacrimal canaliculus.

Natural dental caries in molars of osteogenic disorder Shionogi rats

Osteogenic disorder Shionogi (ODS) rats are genetically defective in ascorbic acid biosynthesis. They exhibit a gait abnormality due to dysfunctional bone formation and display various dental abnormalities. Conditions of the oral cavity and tooth quality both influence the development of dental caries. This study was designed to determine the characteristics of dental caries in ODS/ ShiJclod/od rats. Caries were scored and compared among ODS/ShiJclod/od, ODS/ShiJcl+/+, and Jcl:Wistar retired breeders. Among male rats, the caries scores of the ODS/ShiJclod/od and ODS/ShiJcl+/+ groups were similar to each other but greater than those in Jcl:Wistar rats, whereas among female rats, caries scores in ODS/ShiJclod/od animals were equivalent to or somewhat greater than those in ODS/ShiJcl+/+ rats, whose scores were markedly greater than those of Jcl:Wistar rats. The results suggest that ODS/ShiJcl rats were more susceptible to dental caries than were Jcl:Wistar rats. Under the conditions of the study, caries scores between ODS/ ShiJclod/od and ODS/ShiJcl+/+ rats differed only among parous females.

Occlusal tooth wear in female F344/N rats with aging

OBJECTIVES

This study was conducted to ascertain whether laboratory rats are an adequate animal model for aging oral cavity research, especially on occlusal tooth wear (OTW), which progresses with aging and causes abnormal occlusions. Mastication has been reported to relate to cognition in the elderly. Thus, it is important to care for the oral cavity, especially in the frail elderly, for the maintenance of all-round quality of life. Adequate and appropriate animal models are essential for basic and clinical research on the oral cavity.

METHODS

Dried maxilla and mandible specimens from 98 young, aging or aged female F344/N rats were used.

RESULTS

The levels of OTW of all molars were monitored with aging. The molar tooth began to wear at 1-month old (M) and progressed rapidly till 12M. Subsequently, OTW progressed slowly till 30M, and then rapidly again after 35M.

CONCLUSIONS

This study showed that progress of OTW is well correlated with the entire life span of the rat, and suggested that the rat aged over 12M would be an adequate animal model for research on OTW in middle-aged and elderly people.

Development of IgA nephropathy-like disease with high serum IgA levels and increased proportion of polymeric IgA in Beta-1,4-galactosyltransferase-deficient mice

The glycosylation of glycoproteins is important for their biological activity, conformation and stability. Recent studies indicate that aberrant glycosylation causes various human disorders. Here we report that mice lacking beta-1,4-galactosyltransferase-I (beta4GalT-I), which transfers galactose from UDP-Gal to terminal GlcNAc of N- and O-glycans in a beta-1,4- linkage, developed IgA nephropathy (IgAN)-like disease. Urinary albumin levels were significantly increased in the beta4GalT-I-deficient mice. Hematuria was detected in some of the beta4GalT-I-deficient mice, suggesting impaired renal function. Furthermore, histological and immunohistochemical examination showed expanded mesangial matrix, IgA deposition with mesangial pattern and electron-dense deposits in the paramesangial regions in the beta4GalT-Ideficient mice. These results demonstrate that the beta4GalT-I-deficient mice developed IgANlike disease. Furthermore, high serum IgA levels with increased polymeric forms were detected. In humans, serum IgA derived from patients with IgAN has aberrant beta3-galactosylation and sialylation on its O-linked glycans of the hinge region. Mouse IgA does not have O-glycans of the hinge region and has several N-glycans. As expected, beta4-galactosylation on the N-glycans of the serum IgA of the beta4GalT-I-deficient mice was completely absent. This is the first report demonstrating that genetic remodeling of protein glycosylation causes IgAN. We suggest that aberrant beta4-galactosylation of serum IgA participates in the Nishie/Miyaishi/Azuma/Kameyama/Naruse/Hashimoto/Yokoyama/Narimatsu/Wada/Asano 126 development of IgAN, including deposition of IgA, polymerization of IgA, and glomerular injury after IgA deposition.

Development of immunoglobulin A nephropathy- like disease in beta-1,4-galactosyltransferase-I-deficient mice

Beta4 galactosylation of glycoproteins plays important roles in protein conformation, stability, transport, and clearance from the circulation. Recent studies have revealed that aberrant glycosylation causes various human diseases. Here we report that mice lacking beta-1,4-galactosyltransferase (beta4GalT)-I, which transfers galactose to the terminal N-acetylglucosamine of N- and O-linked glycans in a beta-1,4 linkage, spontaneously developed human immunoglobulin A nephropathy (IgAN)-like glomerular lesions with IgA deposition and expanded mesangial matrix. beta4GalT-I-deficient mice also showed high serum IgA levels with increased polymeric forms as in human IgAN. IgAN is the most common form of glomerulonephritis, and a significant proportion of patients progress to renal failure. However, pathological molecular mechanisms of IgAN are poorly understood. In humans, abnormal character of serum IgA, especially serum IgA1 with aberrant galactosylation and sialylation of O-glycans in its hinge region is thought to contribute to the pathogenesis of IgAN. Mouse IgA has N-glycans but not O-glycans, and beta4-galactosylation and sialylation of the N-glycans on the serum IgA from beta4GalT-I-deficient mice was completely absent. This is the first report demonstrating that genetic remodeling of protein glycosylation causes IgAN. We propose that carbohydrates of serum IgA are involved in the development of IgAN, whether the carbohydrates are O-glycans or N-glycans.

Versican, a major hyaluronan-binding component in the dermis, loses its hyaluronan-binding ability in solar elastosis

Versican interacts with hyaluronan (HA) at its N-terminus and with fibrillin-1 at its C terminus. As versican in the dermis connects microfibrils to the HA-rich matrix for viscoelasticity, dermal diseases may involve destruction of these complexes. A recombinant versican protein, rVN, covering the HA binding region (HABR) of human versican and a polyclonal antibody, 6084, against rVN were prepared and characterized. Blotting analyses of skin extracts with 6084 and biotin-conjugated HA revealed that versican was a major HA-binding component in the dermis. Matrix metalloprotease-12, which is expressed in areas of solar elastosis, degraded versican and abrogated its HA-binding ability. Immunohistochemical analyses revealed that the elastic materials in solar elastosis lesions were negative for 6084, but positive for 2B1, an antibody recognizing the C-terminus of versican, indicating loss of the HABR in the aggregated elastic fibers. This loss of the HA-binding ability of versican followed by HA exclusion may be responsible for the pathological and phenotypical changes observed in solar elastosis.

Lateral canthal support system in Japanese

The present study aimed to elucidate microscopically the precise structure of the generally termed 'lateral canthal tendon' (LCT). Specimens from 9 post-mortem lower eyelids of 6 Japanese aged from 72 to 91 years old at death were fixed in 10% buffered formalin, and microscopically examined. Specimens were excised as exenterated samples including an area 5 mm wider than the orbital aperture. The removed contents were further incised longitudinally on the central eyelid and also incised parallel to the upper eyelid margin on the site 3 mm from its margin. After the preparation of microscopical examination, sections of all 9 eyelids were stained with Hematoxylin and Eosin. We found that the structure generally termed LCT consisted of two definitive different layers microscopically. The superficial layer was only an orbital septum (septal band). It was mainly constituted of thick fibers between adipose-rich tissues. The deep layer continued from the tarsus and projected posteriorly; which was a ligament (tarsoligamentous band). This tissue was constituted by thin, minute fibers with little adipose tissues. The structure generally termed LCT is not a tendon but a complex constitution of an orbital septum and a ligament; which we named, in a mass, 'lateral canthal bands', cooperatively supporting the lateral canthus.

Microscopic Anatomy of Asian Lower Eyelids

PURPOSE

To elucidate the microscopic anatomy of the Asian lower eyelid.

METHODS

Specimens (full-thickness sections of lower eyelids from 19 postmortem lower eyelids) from 11 Asians aged 73 to 96 years at death were fixed in 10% buffered formalin and microscopically examined. After pretreatment, sagittal sliced sections of the central part were stained with Masson trichrome.

RESULTS

The distinct junction of the orbital septum to the capsulopalpebral fascia (CPF) was confirmed in 7 eyelids in which orbital septum was clearly stained, with an average distance from the tarsus to the junction of 2.38 mm. The other 12 eyelids did not show a distinct junction, and the orbital septum was poorly defined anteriorly and indistinct posteriorly. There was a distinct layer between the orbicularis oculi muscle and the orbital septum. The inferior and the posterior attachments of the CPF to the tarsus were seen in all eyelids. Seventeen of the 19 eyelids had attachment of the CPF on the anterior aspect of the tarsus, from which an extension of the CPF through the pretarsal orbicularis oculi muscle was observed. All eyelids had anterior extension of the CPF through the preseptal orbicularis oculi muscle, which was overridden on the pretarsal orbicularis oculi muscle.

CONCLUSIONS

The microscopic findings of Asian lower eyelids, especially fascial components, were mostly similar to those of non-Asian eyelids, but differences existed in higher or indistinct septum fusion, anterior and superior orbital fat projection, and the overriding of the preseptal orbicularis oculi muscle.

An anomalous muscle linking superior and inferior rectus muscles in the orbit

Dissections of the bilateral orbits in a 45-year-old female cadaver, who had no ocular movement disorders in her lifetime, revealed anomalous muscles linking the superior and inferior rectus muscles. The muscles, situated between the optic nerve and the lateral rectus muscle, originated from the annulus of Zinn and branched off two heads; one inserted into the medial inferior side of the superior rectus muscle and the other inserted into the central superior side of the inferior rectus muscle. Each insertion was located on a distal site of the myoneural junction of each rectus muscle. Histological investigations showed that the muscles had a striated muscle structure. No definite nerve insertion was observed in the muscles. Although this type of anomalous muscle has been reported in a few Caucasian cases, the present study is the first report in an Asian person. Anomalous orbital structures, which are a rare cause of strabismus, are important in the differential diagnosis of intra-orbital space-occupying lesions, rather than the differential diagnosis of strabismus.

The lower eyelid retractor consists of definite double layers

PURPOSE

To examine whether the lower eyelid retractor consists of a single layer or multiple layers.

DESIGN

Retrospective clinical case series and dissectional study.

PARTICIPANTS

Fifty-one lower eyelid retractors (31 right, 20 left) of 44 patients (ages, 63-95 years) during entropion surgeries and 10 lower eyelids (5 right, 5 left) of 5 Oriental cadavers (73-91 years old at death) were observed macroscopically. Specimens from 20 postmortem lower eyelids of 12 Orientals (11 right, 9 left; 66-96 years old at death) were used for microscopic observations.

METHODS

Macroscopically, we bluntly or, in parts, sharply dissected lower eyelid retractors into 2 layers during entropion surgeries. Cadaveric lower eyelids also were used to investigate relationships between the lower eyelid retractor and the Lockwood ligament. Cadaveric lower eyelids with sagittal full-thickness sections of the central part were examined microscopically using Masson trichrome staining.

MAIN OUTCOME MEASURES

Anatomical findings in the lower eyelid retractor.

RESULTS

Lower eyelid retractors easily were detached into 2 layers. Macroscopically, the anterior layer was defined as a coarse tissue continuing from the Lockwood ligament, which joined with the lower orbital septum, and constituted the lower conjoined fascia. The posterior layer appeared to be a dense fibrous sheet with a lustrous surface. Microscopically, the lower eyelid retractor consisted of a definite double layer. The anterior layer, a coarse fibrous tissue, consisted of the suborbicularis fascial layer, orbital septum, and superficial part of the capsulopalpebral fascia, which continued to the anterior lamellae of the lower eyelids. The posterior layer consisted of dense fibers of the capsulopalpebral fascia with smooth muscle continuing to the tarsus.

CONCLUSIONS

The lower eyelid retractor consists of a definite double layer. The posterior dense layer containing smooth muscle is the main tractional component of the lower eyelid retractor.

Molecular Cloning and Characterization of Chick SPACRCAN

MY-174, a monoclonal antibody that reacts with specific sialylated O-linked glycoconjugates of chick SPACR (sialoprotein associated with cones and rods), also recognizes another molecule of 300 kDa. Here, we verified that this 300-kDa molecule is chick SPACRCAN (sialoproteoglycan associated with cones and rods), another member of a novel interphotoreceptor matrix molecule family. Screening for chick SPACRCAN was carried out by plaque hybridization using a probe for chick SPACR. Specific polyclonal antibodies raised against chick SPACRCAN were used for the following experiments. To determine whether the 300-kDa molecule detected by MY-174 was identical to 300-kDa chick SPACRCAN, the migrations of these bands were examined after various glycosidase digestions. Furthermore, the expression levels were measured during retinal development and compared with those of chick SPACR. The results demonstrated that the 300-kDa molecule recognized by MY-174 was chick SPACRCAN, and we further identified it as a proteoglycan with chondroitin sulfate chains. SPACRCAN had heavily sialylated N- and O-linked glycoconjugates, and its MY-174 antigenicity was abolished by O-glycanase treatment after neuraminidase treatment, as observed for chick SPACR. During retinal development, the mRNA and core protein expression levels, MY-174 antigenicity, and hyaluronan binding ability of SPACRCAN peaked around embryonic day 17 and then gradually decreased, whereas the corresponding expression levels of SPACR simply increased, but not its hyaluronan binding ability. The MY-174 reactivity of SPACRCAN in the adult retina was decreased compared with that in the newborn retina, whereas that of SPACR was increased. The decreased hyaluronan binding of SPACR was induced by an inhibitory effect of the excess of sialic acids in the adult stage. Thus, with similar core protein structures and specific sialylated glycoconjugates but distinct chondroitin sulfate chains, SPACRCAN and SPACR may have separate roles in the retina due to their differing expression profiles during development.

Identification of genes preferentially expressed in articular cartilage by suppression subtractive hybridization

Suppression subtractive hybridization is very effective to enrich differentially expressed genes in two different tissues or cells. We therefore used the technique to identify characteristic genes expressed in rat knee joint articular cartilage as compared to rat costal cartilage. In this study, we revealed that several genes were enriched in a subtracted articular cartilage cDNA library. The most enriched gene is lubricin that is a putative key molecule for joint lubrication. The second gene is milk fat globule epidermal growth factor (EGF) factor 8, MFG-E8 whose expression has never been observed in cartilage. Other enriched genes are known to be expressed in cartilage, however their differential expressions in cartilages have not been necessarily common. The preferential expression of characteristic genes in articular cartilage would provide unique properties to the tissue. Our findings will provide a new view of articular cartilage.

Posterior Aspect of the Orbital Septum Is Reinforced by Ligaments

PURPOSE

To investigate the ligaments reinforcing the posterior aspect of the orbital septum.

METHODS

Sixteen upper eyelids of eight cadavers of Asians were dissected. Ten were subjected to gross dissections to investigate the ligaments attached to the posterior aspect of the orbital septum and to investigate the relationships with the associated ligamentous structures, and six were used for histological sections to elucidate the ligament anchoring sites in the septum.

RESULTS

The ligaments were attached to the posterior aspect of the orbital septum in both upper and lower eyelids in all cases. Some septa in the upper eyelids were supported by the lower-positioned transverse ligament in the lateral area. In all cases, part of the Lockwood ligament was attached to the posterior aspect of the orbital septum in the lower eyelids. Histologically, the ligaments were anchored to the posterior aspect of the orbital septum.

CONCLUSIONS

The ligaments were attached to the posterior aspect of the orbital septum. These ligaments, in cooperation with the associated ligaments, are thought to complement the fragility of the orbital septum.

Fibrous connective tissue between Müller's muscle and the palpebral conjunctiva as a reinforcement structure and a natural barrier for the upper eyelid

This study was performed to illustrate and discuss the significance of fibrous connective tissue between the Müller's muscle and the palpebral conjunctiva. Nine upper eyelids of 6 Oriental cadavers were microscopically examined; ages at death ranged from 72 to 91 years. Tissue of the posterior lamella of the upper eyelid was removed without the orbital septum and orbital fat. Removed eyelids were incised perpendicularly at the center of the eyelid. After pretreatment, sliced sections were stained with Hematoxylin and Eosin and examined microscopically. A thick fibrous connective tissue was found to exist between the Müller's muscle and the palpebral conjunctiva. The connective tissue continued proximally to the intermuscular transverse ligament and was distally attached to the posterior site of the upper aspect of the tarsus. All cases showed infiltration of lymphocytes from the conjunctiva; however, these were completely blocked by the fibrous connective tissue and never reached Müller's muscle. This connective tissue supports eyelid traction and is a natural barrier for the Muller's muscle against conjunctivitis.

The levator aponeurosis consists of two layers that include smooth muscle

PURPOSE

To investigate the two-fold structure of the levator aponeurosis, which is partly composed of independent smooth muscles.

MATERIALS AND METHODS

Fifteen upper eyelids of 12 Asian postmortems, with age at death ranging from 72 to 91 years, were examined. In 9 eyelids, posterior lamella tissue of the upper eyelid was removed to observe the stratified structures of the levator aponeurosis. Six full-thickness eyelids were used to observe the attachment site or the continuity between the levator aponeurosis and its surrounding tissues. The eyelids were incised perpendicularly in the center of the eyelid; samples were stained with Masson trichrome and antismooth muscle actin antibody and examined microscopically.

RESULTS

Masson trichrome staining demonstrated the two-layered nature of the levator aponeurosis. The anterior layer was characterized by thick, robust fibrous tissue, and the posterior by thinner fibrous tissue. Although both layers contained muscle structures, the posterior layer contained more than the anterior. Immunostaining with antismooth muscle actin antibody revealed that the muscle in both layers was smooth muscle. The anterior layer continued to the orbital septum and the submuscular fibroadipose tissue; the posterior layers, located in front of Müller muscle and its tendon, attached to the anterior inferior one-third of the tarsus. Part of the anterior layer went through the orbicularis oculi muscle and attached to the subcuticular tissue.

CONCLUSIONS

The levator aponeurosis is stratified, consisting of two layers than contain smooth muscle components in their proximal portions. It pulls mainly the preaponeurotic fat and anterior eyelid lamella. This partially regulates the tension of the eyelid and contributes to the ordered movement of the upper eyelid.

Aging changes in the periodontal bone of F344/N rat

The aim of this research was to determine whether a rat was an adequate laboratory animal model for periodontal research on elderly humans. Thirty-two F344/NSlc female rats ranged between 30 and 1000 days of age were used. The alveolar bone loss around the molars was assessed by a morphometric method. A significant correlation was found between age and the amount of alveolar bone loss. For further analysis, the rats were grouped into four by age; 30-60 days, 220-430 days, 640-850 days, and more than 850 days. The means of alveolar bone loss were compared between age groups. It was found that the resorption of the alveolar bone around the molars of the rats continued until they were 1000-days-old, and this trend was stronger in the mandible than the maxilla. It was suggested that rats could be used as adequate laboratory animals for periodontal research.

The levator aponeurosis consists of two layers that include smooth muscle

PURPOSE

To investigate the two-fold structure of the levator aponeurosis, which is partly composed of independent smooth muscles.

MATERIALS AND METHODS

Fifteen upper eyelids of 12 Asian postmortems, with age at death ranging from 72 to 91 years, were examined. In 9 eyelids, posterior lamella tissue of the upper eyelid was removed to observe the stratified structures of the levator aponeurosis. Six full-thickness eyelids were used to observe the attachment site or the continuity between the levator aponeurosis and its surrounding tissues. The eyelids were incised perpendicularly in the center of the eyelid; samples were stained with Masson trichrome and antismooth muscle actin antibody and examined microscopically.

RESULTS

Masson trichrome staining demonstrated the two-layered nature of the levator aponeurosis. The anterior layer was characterized by thick, robust fibrous tissue, and the posterior by thinner fibrous tissue. Although both layers contained muscle structures, the posterior layer contained more than the anterior. Immunostaining with antismooth muscle actin antibody revealed that the muscle in both layers was smooth muscle. The anterior layer continued to the orbital septum and the submuscular fibroadipose tissue; the posterior layers, located in front of Müller muscle and its tendon, attached to the anterior inferior one-third of the tarsus. Part of the anterior layer went through the orbicularis oculi muscle and attached to the subcuticular tissue.

CONCLUSIONS

The levator aponeurosis is stratified, consisting of two layers than contain smooth muscle components in their proximal portions. It pulls mainly the preaponeurotic fat and anterior eyelid lamella. This partially regulates the tension of the eyelid and contributes to the ordered movement of the upper eyelid.

The Lacrimal Canaliculus and Sac Bordered by the Horner's Muscle Form the Functional Lacrimal Drainage System

PURPOSE

To clarify the relationship between the orbicularis oculi muscle, lacrimal canaliculus, and lacrimal sac and to propose a new theory of the lacrimal drainage system.

DESIGN

Dissection study.

PARTICIPANTS

Sixteen Asian cadavers (29 upper eyelids).

METHODS

Gross dissections of the orbicularis oculi muscle in the medial canthus of 10 Asian cadavers were performed, and the relationship between the orbicularis oculi muscle, lacrimal canaliculus, and lacrimal sac was examined. The upper eyelids of the remaining 6 cadavers were dissected grossly, and sections of the lacrimal sac, common lacrimal canaliculus, and upper canaliculus were examined microscopically. The relationship between the lacrimal passage and its surrounding tissues also was examined.

RESULTS

The lacrimal canaliculus and sac both were divided into 2 distinct compartments in relation to the Horner's muscle. The upper half of the lacrimal sac was related to the Horner's muscle through the posterior branch of the medial canthal tendon and connective tissue, and the lower half was related to the capsulopalpebral fascia and orbital fat. The lateral part of the lacrimal canaliculus was covered with the Horner's muscle. The medial part of the lacrimal canaliculus, namely the common lacrimal canaliculus, was not covered by the Horner's muscle, but was covered by the preseptal and orbital parts of the orbicularis oculi muscle on the anterior surface.

CONCLUSIONS

The lacrimal canaliculus and sac were divided into 2 distinct compartments by the Horner's muscle, and it is possible that both contribute to the lacrimal drainage system.

No raphe identified in the orbicularis oculi muscle

This study was performed to elucidate whether the raphe of the orbicularis oculi muscle (raphe) exists or not. Nine upper eyelids of 6 Oriental cadavers with ages at death ranging from 72 to 91 years were dissected; 6 for gross dissections and 3 for histological slice sections. After removing the lateral half of the eyelid skin, the lateral part of the orbicularis oculi muscle and its subjacent tissue were observed macroscopically. The full layered tissue of the 8 mm lateral part from the orbital rim was incised perpendicularly and sections sliced, which were then observed microscopically after staining with the hematoxylin and eosin. The raphe was not identified macroscopically or microscopically. The lateral part of the orbicularis oculi muscle was continuous without the tendinous intercalation; under it, fibrous connective tissue corresponding to the lateral orbital thickening was observed, and in which the band configuration, microscopically the tendinous structure, was formed. The raphe was not identified. The physiological role of the lateral part of the orbicularis oculi muscle is maintained by a less tight attachment of the lateral orbital thickening, but not by the raphe.

The Medial Canthal Tendon Is Composed of Anterior and Posterior Lobes in Japanese Eyes and Fixes the Eyelid Complementarily with Horner’s Muscle

PURPOSE

To report that the medial canthal tendon (MCT) is not simply the aggregate of the orbicularis oculi muscle (OOM) and its tendon.

METHODS

Twenty eyelids of 10 cadavers were used. The cadavers, seven male and three female, were all Japanese, with an average age of death of 76.2 years. The relationship between the MCT and the OOM, and between the tarsus and Horner's muscle were investigated. Histological findings were obtained with hematoxylin and eosin staining.

RESULTS

The MCT was structured with an anterior lobe, the tendon from the tarsal area of the OOM, and a posterior lobe, the muscle-tendon transition area in the orbital area of the OOM. The nasal aspect of the tarsus was fixed by Horner's muscle.

CONCLUSIONS

The MCT and Horner's muscle are located in an important area of the eyelid; therefore, it is essential to understand their precise anatomy.

Cyclooxygenase-2 is a possible target of treatment approach in conjunction with photodynamic therapy for various disorders in skin and oral cavity

BACKGROUND

Anti-cancer effects of cyclooxygenase (COX)-2 inhibitors have been reported, but not fully investigated in skin and oral diseases. 5-aminolaevulinic acid (ALA)-based photodynamic therapy (PDT) for treating those patients with skin and oral lesions is a highly sophisticated procedure, but the incidence of disease recurrence after treatment is rather significant.

OBJECTIVE

To confirm that COX-2 could be a molecular target in adjunctive therapy to ALA-based PDT, we investigated (i) COX-2 expression in various skin and oral diseases, and (ii) the inhibitory effects on cellular growth of COX-2 selective inhibitor (nimesulide), ALA-based PDT and their combination on human oral squamous cell carcinoma (SCC) cell lines.

METHODS

A total of 129 biopsy samples from the skin and oral mucosal lesions were tested immunohistochemically for COX-2 expression. Then the in vitro effects of nimesulide, ALA-based PDT, and their combination were determined on two SCC cell lines, HSC-2 and HSC-4. Three different methods (MTT assay, double-staining for annexin V and propidium iodide, caspase-3/CPP32 fluorometric protease assay) were applied for evaluation of their inhibitory effects on these two cell lines.

RESULTS

Among the skin diseases, a considerable number of COX-2 high expressers were found in actinic keratosis (15 of 25, 60%), Bowen's disease (13 of 17, 76%) and extramammary Paget's disease (15 of 15, 100%). In contrast, only one of 33 (3%) basal cell carcinoma tumours was a COX-2 high expresser. Among the oral mucosal biopsies, the proportion of COX-2 high expressers increased gradually from hyperplasia (one of six, 17%) through mild dysplasia (five of eight, 63%) and moderate dysplasia (20 of 23, 87%) to severe dysplasia (two of two, 100%). Nimesulide had an inhibitory effect in vitro on HSC-2 (proven to be a COX-2 high expresser), but not on HSC-4 (a COX-2 non-expresser). While ALA-based PDT showed an inhibitory effect on both HSC-2 and HSC-4, most importantly the combination of nimesulide and ALA-based PDT demonstrated a significant synergistic effect on the cellular growth inhibition of only HSC-2, but not of HSC-4.

CONCLUSIONS

Our study strongly suggests that COX-2 can be one of the molecular targets in treating various skin and oral diseases. The results from our in vitro experiments also prompt us to develop a new protocol with a combination of COX-2 selective inhibitor and ALA-based PDT for more effective treatment of those diseases.

Difference in average survival between F344/Du and F344/N rats is not due to genetic contamination

The average survival was found to be different between substrains of rats, F344/Du and F344/N. One of the causes of this difference could have been genetic contamination by crossbreeding with other strain(s) after the divergence of substrains. These two strains were examined by PCR-SSLP (simple sequence length polymorphism) procedure using microsatellite (Mit) markers to identify the contamination. All 288 Mit markers distributed throughout the genome exhibited no size polymorphisms between these two strains. This indicated that there was no genetic contamination between these two strains. The phenotypic difference in average survival, thus, is not due to genetic contamination.

Selective expression and functional characteristics of three mammalian hyaluronan synthases in oncogenic malignant transformation

Malignant transformation of fibroblasts and epithelial cells is often accompanied by increased hyaluronan production and accumulation. Despite recent progress in the study of hyaluronan biosynthesis, the mechanisms underlying the transformation-induced overproduction of hyaluronan have not been elucidated. Here we report that activity and transcriptional levels of hyaluronan synthase (HAS) significantly increased after oncogenic malignant transformation of a rat 3Y1 fibroblast cell line. Of three HAS isoforms (HAS1, HAS2, and HAS3), only HAS2 gene expression was increased in the v-Ha-ras transformed 3Y1 cells, which show less malignancy. In contrast, both HAS1 and HAS2 expressions were elevated in the highly malignant cells transformed with v-src and/or v-fos. To assess the contribution of HAS expression to the oncogenic malignant transformation, we established stable cell transfectants expressing sense and antisense HAS genes. Antisense suppression of the HAS2 expression significantly decreased hyaluronan production in the cells transformed by the oncogenic v-Ha-ras and eventually led to a reduction in tumorigenicity in the rat peritoneum. The introduction of the HAS1 and HAS2 genes promoted the growth of subcutaneous tumors in a manner dependent on the levels of hyaluronan synthesis. Significant growth promotion was observed within a wide range of HAS1 expression. In contrast, the growth stimulation was only seen within a narrow range of HAS2 expression, and high levels of HAS2 expression even inhibited tumor growth. These results suggest that proper regulation of the expression of each HAS isoform is required for optimal malignant transformation and tumor growth.

Radioimmunoscintigraphy of intracranial glioma xenograft with a technetium-99m-labeled mouse monoclonal antibody specifically recognizing type III mutant epidermal growth factor receptor

The type III mutant epidermal growth factor receptor (EGFR) is expressed on the cell surface of a subset of glioma, but not of normal tissues. In this study, we investigated the in vivo kinetics of 3C10 mouse monoclonal antibody (mAb), specifically recognizing the type III mutant EGFR (EGFRvIII), using athymic nude mice bearing the intracranial glioma xenograft overexpressing the EGFRvIII. Human glioma cell line, U87MG, expressing the wild type EGFR and the transfectant, named U87MG x deltaEGFR, expressing the EGFRvIII, were transplanted subcutaneously or intracranially to nude mice. 3C10 mAb labeled with a technetium-99m (99mTc) was intravenously injected into these nude mice and then the mice were sacrificed at 24 h later, and the 99mTc-uptake by xenografts and major normal organs was measured to determine the biodistribution of mAb. Furthermore, at 3, 6 and 24 h after injection of 99mTc-labeled 3C10 mAb, whole-body scintigraphy was obtained with a gamma camera to localize the tumor site. 3C10 mAb significantly accumulated to U87MG x deltaEGFR xenografts transplanted subcutaneously or intracranially in nude mice, showing high tumor-to-blood ratio of 10.30 and 4.01, respectively. In contrast, uptake of control antibody in the intracranial tumor was as low as 0.43. In scintigrams, intracranially transplanted U87MG x deltaEGFR xenografts were detectable at 3 h after injection of 99mTc-labeled 3C10 mAb. These results suggest that intravenously injected 3C10 mAb specifically accumulated to the subcutaneous or intracranial glioma xenograft expressing the EGFRvIII and 3C10 mAb is a potential diagnostic and therapeutic agent for patients with gliomas expressing the EGFRvIII.

Heterozygosity with respect to Zfp148 causes complete loss of fetal germ cells during mouse embryogenesis

Zfp148 belongs to a large family of C2H2-type zinc-finger transcription factors. Zfp148 is expressed in fetal germ cells in 13.5-d-old (E13.5) mouse embryos. Germ-line transmission of mutations were not observed in chimeric Zfp148(+/-) mice, and some of these mice completely lacked spermatogonia. The number of primordial germ cells in Zfp148(+/-) tetraploid embryos was normal until E11.5, but declined from E11.5 to E13.5 and continued to decline until few germ cells were present at E18.5. This phenotype was not rescued by wild-type Sertoli or stromal cells, and is therefore a cell-autonomous phenotype. These results indicate that two functional alleles of Zfp148 are required for the normal development of fetal germ cells. Recent studies have shown that Zfp148 activates p53, which has an important role in cell-cycle regulation. Primordial germ cells stop proliferating at approximately E13.5, which correlates with induction of phosphorylation of p53 and its translocation to the nucleus. Phosphorylation of p53 is impaired in Zfp148(+/-) embryonic stem cells and in fetal germ cells from chimeric Zfp148(+/-) embryos. Thus, Zfp148 may be required for regulating p53 in the development of germ cells.

Survival curve modified through dietary restriction (DR) in male Donryu rats

It is well known that dietary restriction (DR) can prolong the life of certain inbred strains of laboratory rodents. This prolongation can be usually shown in a survival curve in parallel to that of non-DR groups. On an outbred strain, Donryu, however, DR resulted in a unique pattern of survival curve. In DR group, the first three quarters of male rats survived longer in a form parallel to non-DR, while the last quarter of them survived far longer in a quite different shape from controlled group. DR may select animals that are capable of longer survival within Donryu. The selection of a quarter animal indicates the parameter for selection may be regulated by a single recessive locus.

Molecular cloning and characterization of chick sialoprotein associated with cones and rods, a developmentally regulated glycoprotein of interphotoreceptor matrix

MY-174 is an IgM class monoclonal antibody originally established against chick PG-M/versican. The antibody specifically stains the photoreceptor layer, where we recently reported an absence of PG-M/versican. In this study, we re-characterized the antibody and identified the molecule that reacts to MY-174 at the photoreceptor layer. Immunohistochemistry localized the antigen to the matrix surrounding photoreceptors. A variety of glycosidase digestions showed that the antigen is the 150-kDa glycoprotein that has sialylated N- and O-linked glycoconjugates having a molecular mass of more than 30-kDa. The peptide sequences obtained from purified MY-174 antigen showed we had sequenced a full-length cDNA with an open reading frame of 2787 base pairs, encoding a polypeptide of 928 amino acids, with 56 and 54% identities to human and mouse sialoprotein associated with cones and rods (SPACRs), respectively, and with the structural features observed in SPACRs. The specific sialylated O-glycoconjugates here are involved in the epitope structure for MY-174. SPACR first appeared by embryonic days 15-16, and expression increased with developmental age, paralleling the adhesion between neural retina and retinal pigment epithelium. Thus, we concluded that the MY-174 antigen at the photoreceptor layer, a developmentally regulated glycoprotein, is identical to chick SPACR and may be involved in a novel system mediating adhesion between neural retina and retinal pigment epithelium.

Significant growth inhibition of human lung cancer cells both in vitro and in vivo by the combined use of a selective cyclooxygenase 2 inhibitor, JTE-522, and conventional anticancer agents

This study reports that a selective COX-2 inhibitor JTE-522inhibits both in vitro and in vivo growth of human lung cancer cells as a single agent. Furthermore, the adjunct use of JTE-522 is shown to significantly enhance treatment efficacy of conventional anticancer drugs not only in vitro but also in vivo without causing any noticeable side effects. Indeed, IC(50)s of various anticancer agents in vitro were reduced by up to 70%, whereas the combination therapy of JTE-522 with docetaxel and vinorelbine inhibited tumor growth in vivo by 65 and 55%, respectively. Taken together, these findings suggest that the use of a selective COX-2 inhibitor in the treatment of lung cancer may be promising, especially because of its enhancement of the treatment efficacy of conventional anticancer agents without compromising quality of life.

Abnormal accumulation of hyaluronan matrix diminishes contact inhibition of cell growth and promotes cell migration

Elevated hyaluronan biosynthesis and matrix deposition correlates with cell proliferation and migration. We ectopically expressed three isoforms of hyaluronan synthase (HAS1, HAS2, or HAS3) in nontransformed rat 3Y1 cells and observed a de novo, massive formation of a hyaluronan matrix that resulted in a partial loss of contact-mediated inhibition of cell growth and migration. All three HAS transfectants showed an enhanced motility in scratch wound assays, and a significant increase in their confluent cell densities. In high-density cultures, the HAS transfectants had a fibroblastic cell shape and markedly formed overlapping cell layers. This phenotype was more pronounced in the HAS2 transfectants than HAS1 or HAS3 transfectants, and occurred with significant alterations in the microfilament organization and N-cadherin distribution at the cell-cell border. Inhibition of a phosphatidylinositol 3-kinase (PI3-kinase) pathway resulted in reacquisition of the normal phenotype of HAS2 transfectants, suggesting that the intracellular PI3-kinase signaling regulates diminution of contact inhibition induced by formation of the massive hyaluronan matrix. Our observations suggest that hyaluronan and its matrix can modulate contact inhibition of cell growth and migration, and provide evidence for functional differences between hyaluronan synthesized by the different HAS proteins.

Adrenal glands in small smooth-tailed tree shrew (Dendrogale murina)

Adrenal glands of small smooth-tailed tree shrews (Dendrogale murina), four males and two females, caught and fixed in Thailand were observed macroscopically and histologically. They were located at the cranio-medial sides of the kidney. They were elongated in shape and consisted of a cortex and medulla. The cortex could be subdivided into three zones by the cell arrangement and the morphology of nuclei, cytoplasm and cell strands, like in other mammalian species. The tree shrew seemed to share more morphological characteristics with some laboratory rodents than some of non-human primates.

[Assisted thoracoscopic resection of huge mediastinal neurogenic tumor with Horner syndrome and superior vena cava syndrome]

A 51-year-old female suffering from right shoulder pain had chest radiography, which showed the huge round shadow (10 x 8.5 x 8.0 cm) on the right upper lung field. Horner syndrome and superior vena cava syndrome were presented. Thoracoscopic appearance showed that the tumor with complete smooth capsulation was neurogenic. After that added ideal thoracotomy (compatible with location and length) was performed, from which tumor was carried out and made a pathologic diagnosis of neurilemoma originated from thoracic sympathetic nerve. Harmonic Scalpel, an ultrasonically activated surgical device was effective in such a case of using near by nerve and small vessels. After operation, superior vena cava syndrome except for Horner syndrome was improved. It is important that we should consider less invasive and safe approach with combination of thoracoscopic and thoracotomic procedures even in case of huge tumor.

Multi-faceted analyses of a highly metastatic human lung cancer cell line NCI-H460-LNM35 suggest mimicry of inflammatory cells in metastasis

This study established and characterized low-metastatic revertant and parental clones of a highly metastatic human lung cancer cell line, NCI-H460-LNM35 (hereafter referred to as LNM35). Expression-profiling analysis revealed that up-regulation of various proinflammatory cytokines and angiogenic chemotactic chemokines was present in LNM35. Further, while COX-2 itself is known to be inducible in inflammation, COX-2 expression levels correlated well with the capabilities of these clones for not only in vitro motility and invasion but also in vivo metastasis, and COX-2 inhibitors were shown for the first time to reduce lung cancer metastasis in vivo. These findings suggest that lung cancer cells may mimic inflammatory cells in the process of metastasis.

Macrophage colony-stimulating factor is expressed in neuron and microglia after focal brain injury

In a previous study, we have demonstrated that damaged neurons within a boundary area around necrosis fall into delayed neuronal death owing to the cytotoxic effect of microglial nitric oxide (NO), and these neurons are finally eliminated by activated microglia. In this process, microglia are activated to release NO, increase in number, and accumulate toward the damaged area. In this study, we investigated the expression of macrophage colony-stimulating factor (M-CSF, also called colony stimulating factor-1; CSF-1) and other cytokines, which are reported to relate to activation, proliferation, or migration of microglia. The mRNA of M-CSF arose biphasically from 30 min to 1 hr and from 6 to 72 hr after the injury, as demonstrated by semiquantitative RT-PCR. However, another cytokine of granulocyte-macrophage CSF (GM-CSF) or interleukin-3 (IL-3), which causes proliferation of microglia in vitro, was not detected. From immunohistochemical studies, positive staining of M-CSF was observed mainly in neuron-specific enolase (NSE)-positive cells from 1 to 12 hr after the injury, and after that M-CSF became positive in Griffonia simplicifolia isolectin-B4 (GSA-I-B4)-positive cells from 24 to 72 hr in the boundary area around necrosis. These results suggest that neurons around the damaged area express M-CSF in the early phase after injury, which may initially activate microglia, and these activated microglia also express M-CSF later, causing further proliferation or migration of microglia themselves to eliminate damaged neurons or necrotic brain tissue.

Age-dependent changes in noradrenergic innervations of the frontal cortex in F344 rats

Noradrenergic innervations of the frontal cortex with advancing age (9, 13 and 25 months) in male F344 rats were quantified by immunohistochemistry for dopamine-beta-hydroxylase (DBH), which is a marker enzyme for noradrenergic axons. The density of DBH-positive axons, varicosities (swellings along an axon from which noradrenaline is released), and the number of varicosities per unit length of axon were measured in the frontal cortex. We found that the density of axons and varicosities significantly decreased at an earlier stage of aging (9-13 months), but not at a later stage (13-25 months). On the other hand, the number of varicosities per unit length of axon did not change with age. The result shows that the density of varicosities, which represent the synapses of noradrenergic neurons, decrease in the frontal cortex in the early aging process.

A group of five parameters as a new biological marker on F344/N rats

The National Institute for Longevity Sciences (NILS) established an aging farm (A/F) for producing aging/aged laboratory rodents at the Experimental Animal Facility Wing under the NILS A/F Guide planned by the Laboratory Animal Research Facilities (LARF). Five parameters, the average life span, the number of days of 75, 50, and 25% survival points, and average of the top 10 longest life span among laboratory strains of rodents at NILS-A/F, were reproducible for F344/N rats specifically by strain and sex under the LARF A/F guide. These five parameters may serve as an effective and practical biological marker, especially in aging science including longevity science, to evaluate characteristics of strains of laboratory rodents. The five parameters can identify clear substrain differences between F344/N and F344/Du and breeder differences between F344/DuCrj and F344/DuCrl.

Magnetic resonance imaging of myxoma in the mandible: a case report

The findings of conventional radiography, computed tomography, and magnetic resonance imaging (MRI) are reported for an odontogenic myxoma arising in the mandible of a 48-year-old Japanese man. The MRI characteristics of an intraosseous myxoma are described for only the third time. MRI showed a well-defined and smooth-walled mass lesion with high-signal intensity on T2-weighted images and low-intermediate-signal intensity on TI-weighted images. Soft tissue myxomas have been reported to show low-signal intensity on TI-weighted images and high-signal intensity on T2-weighted images. However, the first MRI report of an intraosseous myxoma showed a higher-signal intensity on TI-weighted images and lower-signal intensity on T2-weighted images. The MRI findings in this study thus correspond to those of soft tissue myxomas and do not agree with observations of the first MRI report of the intraosseous myxoma. Further studies are needed to clarify the reasons for this difference.

The diagnostic significance of left auricular thrombus in F344/N rats

In the process of assessing the main cause of death in F344/N rats from the aging farm of our institute, we have often found left auricular thrombus in autopsy cases of moribund animals. In 319 autopsy cases, 45 were of left auricular thrombus and 44 were accompanied by hematopoietic neoplasms, including overt leukemia and a pre-leukemic condition of leukemia. In cases without splenomegaly, this lesion was found in 13 of 21 animals (61.9%) whereas, in cases with splenomegaly, 31 of 239 were positive for this lesion (13.0%). Thus, left auricular thrombus may be an important macroscopic diagnostic criteria of hematopoietic neoplasms, especially when splenomegaly is absent. Furthermore, this lesion tended to arise in aged animals despite the presence of splenomegaly. These results would therefore greatly contribute to aging science by confirming the health condition of experimental rats and the accuracy of subsequent results.

Cu/Zn- and Mn-superoxide dismutases are specifically up-regulated in neurons after focal brain injury

In previous studies, we have demonstrated that damaged neurons within a boundary area around necrosis fall into delayed cell death due to the cytotoxic effect of microglial nitric oxide (NO), and are finally eliminated by activated microglia. In contrast, neurons in a narrow surrounding region nearby this boundary area remain alive even though they may encounter cytotoxic NO. To investigate the mechanism by which neurons tolerate this oxidative stress, we examined the in vitro and in vivo expression levels of superoxide dismutase (SOD) under pathological conditions. Results from our in situ hybridization and immunohistochemical studies showed up-regulation of Cu/Zn-SOD only in neurons outside the boundary area, whereas up-regulation of Mn-SOD was detected in both neurons and glial cells in the same region. In vitro experiments using rat PC12 pheochromocytoma and C6 glioma cell lines showed that induction of both Cu/Zn- and Mn-SOD mRNA could only be detected in PC12 cells after treatment with NO donors, while a slight induction of Mn-SOD mRNA alone could be seen in C6 glioma cells. The mechanism of resistance toward oxidative stress therefore appears to be quite different between neuronal and glial cells. It is assumed that these two types of SOD might play a critical role in protecting neurons from NO cytotoxicity in vivo, and the inability of SOD induction in damaged neurons seems to cause their selective elimination after focal brain injury.

Cancer incidence in old age

The incidence of all cancer increases with age through most of the human life span, but its real incidence at very old ages has not been well elucidated to date. Clarification of the real incidence of cancer in old age, especially among centenarians, may well provide pivotal information to understand the characteristics of humankind. In this study, autopsy records of the Annual of the Pathological Autopsy Cases in Japan, 1991-1996, vols. 34-39 (Japanese Society of Pathology, Tokyo) were used. Cases over 90 years old were studied individually for accurate analysis. The incidence of cancer peaked in the 6th decade and that of multiple cases in the 8th decade. In groups over 90 years of age, the incidence at 5-year intervals did not show any significant decrement. Moreover, the metastatic rate and rate of death due to cancer among centenarians was about three-fourths and two-thirds, respectively, of that of cases aged 90-94 years. The decrease in the metastatic ratio and less mortality due to cancer occurring at the oldest ages are considered due to the nature of cancer itself. The fact that the incidence of cancer does not increase would suggest that certain people among those of advanced age have a special resistance to it.

Establishment and characterization of a human lung cancer cell line NCI-H460-LNM35 with consistent lymphogenous metastasis via both subcutaneous and orthotopic propagation

Lymphogenous metastasis is a common feature of human lung cancers, but very little is known about the underlying mechanism. In the present study, in vivo selection was carried out to obtain a highly lymphogenous metastatic subline of a human large cell carcinoma of the lung, NCI-H460. The resulting subline, termed NCI-H460-LNM35 (LNM35), was shown to metastasize to regional lymph nodes with a 100% incidence not only as a result of orthotopic intrabronchial (i.b.) implantation, but also as a result of conventional s.c. implantation. LNM35 has a short latency period, allowing for the collection of experimental data within 28 days after i.b. inoculation and 45 days after s.c. inoculation. It was noted that orthotopically i.b.-propagated LNM35 closely mimicked the clinical manifestations of human lung cancer patients by infiltrating into lymphatic vessels and metastasizing to the mediastinal lymph nodes. The LNM35 cell line is, to the best of our knowledge, the first human lung cancer cell line to be reported as having lymphogenous metastatic properties, and the observed 100% incidence by s.c. inoculation gives LNM35 a significant advantage even over previously reported human cancer cell lines of other origins. Comparisons between LNM35 and its parental NCI-H460 cell lines were also made with regard to expression levels and/or activities of various molecules that are thought to play a part in the metastatic process. We show here that the expression of cyclooxygenase 2 is increased in LNM35 and that a specific cyclooxygenase 2 inhibitor, nimesulide, can inhibit the invasion of LNM35 in vitro through Matrigel containing basement membrane components.

Anisocytosis precedes onset of the large granular lymphocyte leukemia in aged F344/N rats

In investigations using experimental animals, the unexpected affection of certain diseases often cause great impairment to them especially when using aged animals. In F344 rats, large granular lymphocyte leukemia is the most frequent fatal disease which increases along their aging. The timely detection of rats at risk for leukemia is very important in order to exclude such animals and thus obtain precise results in many fields of investigation. In the process of assessing the main cause of death in F344/N rats of the aging farm of our institute, NILS, we found cases with no obvious contributory disease to death that showed anisocytosis in a peripheral blood smear. In such cases, histological examination of spleen revealed consistent features of leukemia and findings of the liver and kidney were considered due to this hematologic disorder. Anisocytosis was frequently seen in the advances stage of leukemia. Thus we concluded that anisocytosis is a prior condition of leukemia and its detection in a peripheral blood smear is predictive of the disease when using aged animals.

Differences in survivability among F344 rats

Important parameters to identify and develop appropriate animal models for longevity science include survivability, age-related disorders, and easy handling of aged individuals. It is found that F334/Du and F344/N have distinctive strain difference in these parameters. The finding suggests F334/Du and F344/N, even though they are historically siblings, need clearly separate identification when used as animal models for aging science, in particular, longevity science.