Tissue distribution of the DNA binding oncoprotein Maf during chicken development

To assess the normal function of the c-maf protooncogene product, we examined its tissue distribution during fetal growth and organogenesis of the chicken using an immunohistochemical technique. Nuclei of neuronal cells in the optic lobe and in the outer granular layer of the cerebral cortex were efficiently stained by anti-Maf serum throughout all developmental stages examined. In the lung, mesenchymal cells were stained intensely by the antiserum, with the most intense staining around embryonic day 15. During the embryonic period, nuclei of mesenchymal cells in the perichondrial and periosteal tissues as well as intestinal submucosa were also stained specifically by the antiserum. In addition, we detected substantial Maf immunoreactivity in nuclei of renal glomerular and proximal-tubular epithelial cells. These results suggest that c-Maf protein plays some important roles in the development of the central nervous system and tissues of mesodermal origin such as connective and renal tissues.

Gammopathy with two M-components in a dog with IgA-type multiple myeloma

A 12-year neutered male mixed-breed dog was referred to hospital for evaluation of chronic diarrhea. Cellulose acetate electrophoresis of its serum revealed two monoclonal peaks in the gamma-globulin fraction. On immunoelectrophoretic analysis, the two monoclonal peaks in the gamma-globulin region were strongly precipitated with anti-dog IgA serum. On sodium dodecyl sulfate-polyacrylamide gel electrophoretic analysis, the fractions corresponding to these two peaks were shown to be dimer and trimer or tetramer of immunoglobulin consisting of heavy and light chains. These results indicated that the studied dog had gammopathy with two M-components with dimer and trimer or tetramer of IgA. Accumulations of large amounts of these immunoglobulins with very high molecular weight in the serum were concluded to induce the hyperviscosity syndrome in this dog in the terminal stage.

Sequence analysis of the Streptococcus mutans Ingbritt dexA gene encoding extracellular dextranase

The complete nucleotide sequence (3,747 bp) of the dextranase gene (dexA) and flanking regions of the chromosome of Streptococcus mutans Ingbritt (serotype c) were determined. The open reading frame for dexA was 2,550 bp, ending with a stop codon TGA. A putative ribosome-binding site, promoter preceding the start codon, and potential stem-loop structure were identified. The presumed dextranase protein (DexA) consisting of 850 amino acids was estimated to have a molecular size of 94,536 Da and a pI of 4.79. The nucleotide sequence and the deduced amino acid sequences of S. mutans dexA exhibited homologies of 57.8% and 47.0%, respectively, to those of Streptococcus sobrinus dex. The homologous region of dex of S. sobrinus was in the N-terminal half. The C terminus of DexA consisted of a hexapeptide LPQTGD, followed by 7 charged amino acids, 21 amino acids with a strongly hydrophobic character, and a charged hexapeptide tail, which have been reported as a common structure of C termini of not only the surface-associated proteins of Gram-positive cocci but also the extracellular enzymes such as beta-fructosidase of S. mutans and dextranase of S. sobrinus. The DexA protein had no significant homology with the glucosyltransferases, the glucan-binding protein, or the dextranase inhibitor of mutans streptococci.

Senile plaques in an aged two-humped (Bactrian) camel (Camelus bactrianus)

Senile plaques with beta-protein as a major constituent are a conspicuous feature in the brains of aged humans, monkeys, dogs, and bears. We found cerebral senile plaques of the diffuse and primitive type, but not the classical type, in an aged female camel of more than 20 years old. The senile plaques and a few cortical capillaries were immunoreactive with anti-beta-protein serum. Congophilic amyloid deposition was detected in a small number of the capillaries, but not in the senile plaques. We believe this to be the first detailed report of senile plaques in a herbivore, and these findings suggest the possibility of senile plaque formation in a wide variety of mammalian species.

Morphometric analysis of neurons in ganglia: geniculate, submandibular, cervical spinal and superior cervical

The geniculate ganglia (GG), the submandibular ganglion (SG), the cervical spinal ganglion (CSG) and the superior cervical ganglion (SCG) are clinically important. But details of these ganglia have not been included in textbook descriptions. We conducted research to bring precise figures to light. We prepared serial sections of these ganglia in five Japanese adults after precise dissections to count the numbers, measure the perimeters and the areas, and calculate the circularity ratios (CRs) of the ganglion cells. The numbers of neurons were in the following order: SCG > CSG > SG > GG, and the average neuronal areas in the following order: CSG > GG > SG > SCG. Average neuronal CRs were around 0.90 in all ganglia. In other words, the morphometric evaluation showed that neurons in such ganglia are practically circular in shape. Our morphometry thus reveals that the neurons in these ganglia are sensory neurons in the broad definition of the word from a quantitative point of view.

Eosinophilic neuronal inclusions in the thalamus of ageing B6C3F1 mice

The age-related incidence of thalamic neuronal inclusions in the brains of aged B6C3F1 mice and their histopathological and ultrastructural features were studied. Round to oval or rod-shaped eosinophilic inclusions, which were frequently observed in the neurons of the thalamic area, were stained positively with phosphotungstic acid haematoxylin. The inclusions were detected first at 32 weeks of age and the incidence and severity were higher in older animals, all of the mice being affected after 58 weeks of age. Ultrastructurally, the inclusions appeared as sheaves of parallel osmiophilic filaments in the perikaryon of the neurons in the thalamus. Thus thalamic neuronal inclusions in mice seem to be age-related, but their significance remains unclear.

[Histopathological studies on senile plaques and cerebral amyloid angiopathy in aged cynomolgus monkeys]

The incidence and morphological characteristics of senile plaque and amyloid angiopathy in the cerebrum of six aged cynomolgus monkeys (Macaca fascicularis), 20 to 29 years old, were studied histopathologically and immunohistochemically. By periodic acid methenamine silver stain (PAM) and alkaline Congo red stain, senile plaques were detected in 5 out of 6 cases, and 3 of them were positive for amyloid in the wall of capillaries and arterioles in the cerebral cortex. Senile plaques were classified into three types. Mature plaques, including classical and primitive types, were more frequently observed than the immature diffuse type. Senile plaques were often seen in the cortex of temporal lobe, putamen and head of caudate nucleus. Since mature types of senile plaques were seen frequently around vascular amyloid deposition and no amyloid angiopathy was detected in the areas without senile plaques, the close relation between senile plaque of the mature type and amyloid angiopathy might be considered. All senile plaques and amyloid angiopathy were positively stained immunohistochemically with antibody against amyloid beta-protein (A beta P) 1-40 synthetic peptide, but all diffuse and some primitive plaques were negative for antibody against A beta P 8-17 synthetic peptide. Neither senile plaque nor amyloid angiopathy was detected in the cerebrum of 15 young monkeys, 9 to 11 years old, examined as controls.

Senile plaques and other senile changes in the brain of an aged American black bear

A female American black bear (Euarctos ursus americanus) over 20 years old had shown epileptiform neurologic signs starting in March 1992 and was found dead unexpectedly 8 months later. At necropsy, pulmonary and intrabronchial hemorrhage was noted. In the brain, the leptomeninges exhibited slight thickening, and petechiae were evident in the hippocampus. Histopathologic examination of the brain revealed several senile changes: numerous senile plaques, amyloid deposition in cerebromeningeal arterioles, mineral deposition in the pallidum, and numerous corpora amylacea in the cerebellum.

Characterization of the dextranase gene (dex) of Streptococcus mutans and its recombinant product in an Escherichia coli host

The gene (dex), which encodes the Streptococcus mutans dextranase (Dex), was cloned in Escherichia coli. The E. coli host harboring a recombinant plasmid (pSD2) containing an 8-kb BamHI insert produced a Dex protein of 133 kDa as well as smaller enzymes of 118, 104, and 88 kDa. The Dex produced by the recombinant E. coli was apparently located in the cytoplasmic fraction, not in the periplasmic nor the extracellular fractions. Subcloning and deletion analysis of pSD2 showed that the structural gene of Dex was encoded by a 4-kb BamHI-SalI fragment. The fragment also contained the dex promoter which was effective in the E. coli cell.

Apoptosis in the central nervous system of developing mouse fetuses from 5-azacytidine-administered dams

To determine the effect of 5-azacytidine (5 Az), a cytidine analogue, on the developing fetus, different strains of mice were injected with various doses of the agent, ip, at 11 days of gestation. Light microscopically, severely pyknotic cell death profiles were observed in different layers of the developing brain and spinal cord (central nervous system) on the day after the injection. Electron microscopy of the pyknotic cells revealed the shrinkage of the cell body, to various degrees margination of the nuclear chromatin, condensation of nuclear materials, fragmentation of the affected cells, and, finally, neat "bite-size" bodies engulfed by surrounding normal neuroepithelial cells and macrophage-like cells. DNA fragmentation was detected in the nuclei of the pyknotic cells by an in situ detection method for fragmented DNA ends. These changes were consistent with the criteria of apoptosis.

Identification and minisatellite linkage analysis of SMXA recombinant inbred strains of mice by DNA fingerprinting

SMXA recombinant inbred (RI) strains of mice were produced by systematic inbreeding from the F2 generation of a cross between two progenitor inbred strains, A/J and SM/J, which differ considerably with respect to many characteristics, and consists of 28 inbred strains. In this study, we investigated the applicability of DNA fingerprinting with M13 phage DNA to the identification of these closely related strains. DNA fingerprints of the SMXA RI strains and their progenitors, SM/J and A/J, showed strain-specific patterns, with the same banding patterns within each strain. Linkage analysis by using strain distribution patterns of minisatellite loci with 108 genetic markers containing microsatellites, biochemical and immunological marker genes allowed 23 minisatellite loci to be assigned to 11 chromosomes. The results suggested that DNA fingerprinting with M13 phage DNA is applicable not only for strain identification but also for genetic monitoring of RI strains on almost all chromosomes.

Erythroleukemia in two cats naturally infected with feline leukemia virus in the same household

Erythroleukemia was observed in two unrelated cats infected with feline leukemia virus (FeLV) from the same household. Case 1, a 1-year-old neutered male cat developed erythroleukemia (M6) after a diagnosis of myelodysplastic syndrome (MDS-Er) on the criteria of FAB classification of acute leukemias. Case 2, a 1-year-old neutered female cat, which had close contact with Case 1, also developed erythroleukemia (M6Er). In both cases, marked proliferation of erythroid progenitor cells with disproportionally large numbers of immature forms was observed in the bone marrow. In Case 1, neoplastic proliferation of myeloid cells in the bone marrow was also noted at the terminal stage. Combination chemotherapy with daunomycin was partially effective for treatment of these erythroid neoplasias, but did not induce complete remission. Southern blot analysis using exogenous FeLV-specific probes indicated the clonal origin of these hematopoietic tumor cells. Furthermore, the erythroid and myeloid tumor cells in Case 1 were shown to be derived from independent transformed clones. A variant FeLV was shown to be integrated into the tumor cells in Case 1, while a full-length FeLV was found in both cases. Because these erythroid neoplastic diseases occurred in two unrelated cats kept in the same household and these diseases are rare, they may both have been associated with the same FeLV strain.

Nucleotide sequence of the SrRNA gene of Entamoeba gingivalis: applications for construction of a species-specific DNA probe and phylogenetic analysis

The small subunit ribosomal RNA (SrRNA) gene of Entamoeba gingivalis was amplified by PCR and the product of 1.9-kbp sequence was cloned into a plasmid vector pUC18. Four clones were isolated and sequenced. The insert DNAs were 1918- to 1921-bp long and A+T rich (65.5%). The four SrRNA sequences of E. gingivalis were found to be aligned with those of nine related protozoans while searching for E. gingivalis-specific sequences. A sequence of 28 oligonucleotides was chosen, chemically synthesized, and labeled with digoxigenin for use as a DNA probe. The probe thus constructed was shown to hybridize only with either the SrRNA-coding DNAs or the cells of the two E. gingivalis strains and not with those of other protozons or oral fungi tested. A representative SrRNA-sequence was analyzed and a phylogenetic tree was constructed by the neighbor-joining (NJ) method. Among the protists examined, E. gingivalis was placed next to Entamoeba histolytica as expected from the traditional taxonomy.

Separation of outer cysts from metacercariae of Fasciola gigantica in an aqueous two-phase system

The outer cysts (Oc) of Fasciola gigantica metacercariae (Mc) were separated in an aqueous two-phase system composed of polyethylene glycol and dextran in distilled water. A large number of separated Mc without Oc were recovered in the bottom layer rich in dextran in the system. Ten separated Mc in the layer were used to inoculate the mouse with a syringe and juveniles were recovered from the animals on the 14th day. When the number of juveniles recovered was compared with that from the mice infected orally with the same number of Mc, there was a significant difference between them (P < 0.05). The former method is easier than the latter for inoculation.

Cloning of canine osteosarcoma cells

Six clonal cells were established from a canine osteosarcoma cell line (POS) by a limiting dilution method using feeder cells. Whereas histology of mass developed in nude mice by transplantation of POS cells revealed various cell types, clonal cells were morphologically consistent in size and shape. Doubling time of clonal cells ranged from 30 +/- 1.4 to 54 +/- 1.3 hr and alkaline phosphatase activity ranged from 0.040 +/- 0.001 to 2.61 +/- 0.435 mumol/min/mg protein depending on the cell types. When transplanted into nude mice, each clonal cell type formed following four histological types; osteoblastic, chondroblastic, fibroblastic, and undifferentiated types. Since each histological feature was found simultaneously in the primary tumor, osteosarcoma tissue might be a complex of various types of cells having different characteristics. Therefore, POS clonal cells may be useful as a potential tool for the studies of differentiation, phenotypic expression, and a new therapeutic modality of osteosarcoma.

[Lymphatics of the thoracic surface of the diaphragm especially located around the inferior surface of the pericardial sac]

The lymphatics on the thoracic surface of the diaphragm, especially lying around the lateral and posterior sides of the base of the cardiac sac, were examined in 68 adult Japanese cadavers macroscopically (37 males and 24 females, aged 45-92 years, no clinical evidences of neoplasms). In this observation, a vein which drained into the terminal portion of the inferior vena cava was observed. The lymph nodes in this region were located along the vein frequently (80.9%). The vein passed through the esophageal hiatus, or penetrated the diaphragm and finally communicated with veins around the esophagogastric junction. However, lymphatic vessels were not observed passing through the phrenico-esophageal membrane and/or the diaphragm. The collecting vessels, which originated from the lymphatics, drained into the esophageal lymphatics, and it drained into the thoracic duct via the esophageal lymphatics. In pleural effusion cases, lymphatic nets were clearly observed on the thoracic surface of the diaphragm immediately under the parietal pleura. The lymphatic nets did not communicate with the diaphragmatic lymphatics around the base of the cardiac sac. Moreover, large collecting vessel from the lymphatic nets passed through the muscular crus of the diaphragm near the medial arcuate ligament and traveled inferior to merge at the original portion of the thoracic duct at the level of the renal vessels. From these observations, the lymphatics on the posterior part of the thoracic surface of the diaphragm communicated with several regional lymphatics independently. This morphological lymphatic traveling suggests that the route differs in cases of pleural effusion or cancer metastasis.

Age-related changes in thyroid lesions and function in F344/DuCrj rats

Age-related thyroid changes, such as those in weight, histology, morphometry, and hormonal concentrations were evaluated in 460 male and 460 female F344 rats from 9 to 109 weeks of age. The absolute weight of the thyroid increased with age in both sexes, but the relative weight was unaffected by age. Ectopic thymus and ultimobranchial cyst were observed in rats of both sexes from 9 to 109 weeks of age. The incidence of both congenital anomalies decreased with age. The incidence of follicular cyst, which was first observed in rats at 20 weeks of age, increased at 109 weeks. Hyperdistention of the follicle with infiltration of macrophages in the lumen and deposition of brown pigments in the cytoplasm of epithelial cells were observed in a few rats at 59 weeks of age. These follicular lesions were found in 29% of the males and 7% of the females at 109 weeks. The first thyroid tumor was seen at 59 weeks of age. In 109-week-old rats, 5% of males had follicular tumors, and 18% of males and 10% of females had C-cell tumors. At 82 weeks of age, the follicular area and the area of the follicular lumen increased, and the height of follicular epithelial cells decreased. Serum T3, T4 and TSH concentrations decreased with age and were significantly reduced at 82 weeks. These results suggest that in F344 male rats the thyroid structural and functional changes occurred with age, and thyroid function decreased after 82 weeks of age.

Development of the human medial superior olivary nucleus: a morphometric study

The development of the human medial superior olivary nucleus was studied in serial sections of 10 fetuses at 12-35 weeks of gestation (WG), an infant at 2 months of age and an adult of 63 years using an electronic planimeter with a computer. Morphometric analysis suggested that the development of the human medial superior olivary nucleus accelerates between 16 and 21 WG in terms of columnar lengths and volumes, neuronal sizes and circularity ratios, while it matures gradually in terms of the amount of Nissl bodies.

A novel method for regenerating plants from mesophyll protoplasts of Arabidopsis thaliana line WS

A procedure has been developed for the successful regeneration of plants from mesophyll protoplasts of Arabidopsis thaliana line WS. The protocol is an improved version of that of Damm and Willmitzer (1988).The main changes in original procedure are as follows: (1) A mixture of Cellulase Y-C (0.5%) and Pectolyase Y-23 (0.05%) is used for the isolation of protoplasts. Use of these enzymes reduces the incubation time to 50 min. (2) α-Naphthaleneacetic acid is used as the auxin throughout cultures of protoplasts and calli. (3) Protoplasts and calli are incubated under dim white light (0.8-8 μW/cm(2)) during culture. With these modifications, we were able consistently to obtain regenerated shoots from about 70% of calli that had been transferred to shoot-forming medium even though the plating efficiency was rather low (about 0.5-1.5%).

Histopathological findings of the digits in dairy cows in Japan

Two hundred and thirty-nine digits of 45 Holstein dairy cows, which were raised in typical Japanese dairy farms and received poor hoof management, were randomly obtained in the slaughterhouses and examined histopathologically. The findings were classified into 5 grades on the basis of the severity of circulatory disturbances and of keratogenesis. The lesions from Grade 1 to 5 were considered as manifestations of serial lesions indicating that subclinical laminitis advanced to other hoof lesions. The incidence of Grade 2, regarded as subclinical laminitis, reached approximately 50% of digits examined. The lesions classified as Grades 3 (23.9%) and 4 (5.4%) were mainly characterized by circulatory disturbances, which were similar to those of chronic laminitis in the previous reports. The incidence of Grade 5, characterized by sole ulcer, was 5.4%. It is suggested that a considerable number of daily cows in Japan suffered from subclinical laminitis, which may be the cause of recent high incidence of hoof diseases in dairy cows.