Expression of Protein Kinases C βI, βII, and VEGF during the Differentiation of Enamel Epithelium in Tooth Development

Protein kinase C (PKC) is an important molecule involved in various cell function, and mediates induced secretion of vascular endothelial growth factor (VEGF). It is hypothesized that PKC and VEGF may be associated with tooth development. Using the laser microdissection method and real-time reverse-transcription-polymerase chain-reaction (RT-PCR), we investigated the expression of PKC βI and βII, VEGF, and amelogenin (used as a marker of differentiation to ameloblasts) in the inner and outer enamel epithelia, stellate reticulum, and dental papilla in each stage of the dental germ. We found that the expression levels of PKC βI and βII were increased in the inner enamel epithelium during the early bell stage. In addition, the increased expression levels of PKC βI and βII were accompanied by increased VEGF expression. These results indicate that PKC βI, βII, and VEGF are closely associated with the differentiation of the inner enamel epithelium to ameloblasts.

Tuning surface grafting density of CeO2 nanocrystals with near- and supercritical solvent characteristics

In this work, the solvent effect on the synthesis of CeO₂ nanocrystals prepared in near- and supercritical alcohols is discussed.

Functional supramolecular polymers

Supramolecular polymers can be random and entangled coils with the mechanical properties of plastics and elastomers, but with great capacity for processability, recycling, and self-healing due to their reversible monomer-to-polymer transitions. At the other extreme, supramolecular polymers can be formed by self-assembly among designed subunits to yield shape-persistent and highly ordered filaments. The use of strong and directional interactions among molecular subunits can achieve not only rich dynamic behavior but also high degrees of internal order that are not known in ordinary polymers. They can resemble, for example, the ordered and dynamic one-dimensional supramolecular assemblies of the cell cytoskeleton and possess useful biological and electronic functions.

Development of a solid medium for growth and isolation of axenic microcystis strains (cyanobacteria)

Solid media on a base of B-12 or CB medium with agarose or agarose of low melting temperature were developed for the cultivation of Microcystis species. The media with 0.4% gel showed the highest number of CFU, and increasing the gel concentration resulted in a reduction of the number of CFU. There was no difference in the numbers of CFU between pour and spread plates made of the solid media. By using the solid media, 31 clones of Microcystis species were isolated from natural blooms in Lake Kasumigaura, and 5 axenic strains (1 of M. wesenbergii and 4 of M. aeruginosa) were established from the clones.

Effects of latency period in a rabbit mandibular distraction osteogenesis

Recently, distraction osteogenesis has been widely used in the craniomaxillofacial skeleton. There are varying views, however, about the need for a latency period for mandibular distraction, which has been reported from 0 to 14 days. We used a rabbit model to determine the ideal latency period for mandibular distraction osteogenesis. We performed a subperiosteal corticotomy of the bilateral mandible and then applied an external device. We used 0-, 2-, 5-, and 10-day latency periods. Distraction was done at a rate of 0.5 mm per day (0.25 mm every 12 h) to elongate by 5 mm after each latency period. Hematoxylin-eosin stain was used for histologic observation, and bone labelling was observed with a fluorescence microscope. In the 0-day latency, the lengthened region was filled with fibrous tissue. Cartilage formed like isles along the lengthened edge. In the 10-day latency, the lengthened region was almost completely filled with woven bone. In the 2- and 5-day latency, there were mineralization zones at the periphery of this fibrous interzone. The primary osteon remodelling zones were located at both ends of the zones of mineralization zones. In the 5-day latency, new bone formation was observed around the periosteum.

Polarized angular dependent spectroscopy of epithelial cells and epithelial cell nuclei to determine the size scale of scattering structures

An understanding of the relationship between tissue structures and light scattering from tissue will help facilitate the development and acceptance of noninvasive optical diagnostics including elastic scattering spectroscopy, diffuse reflectance, and optical coherence tomography. For example, a quantitative model of the structures that scatter light in epithelial cells would allow determination of what structures control the characteristics of in vivo light transport measurements and subsequently could provide a detailed relationship between cellular structures and optical measurements. We have determined the size distribution of refractive index structure variations in epithelial cells as well as in nuclei isolated from epithelial cells from measurements of the angular dependence of polarized light scattering. The quantitative size distributions we obtained for both whole cells and isolated nuclei include particles with effective radii of 2 microm to 10 nm or less and contain orders of magnitude more small particles than large particles. These results demonstrate that not only are biological cells very heterogeneous, but so are the nuclei within them. Light scattering is likely sensitive to structures smaller than those commonly investigated by standard pathology methods.

Expression of a green fluorescent protein variant in mouse oocytes by injection of RNA with an added long poly(A) tail

In oocytes, cytoplasmic 3' polyadenylation regulates translational activation of dormant mRNA during meiotic maturation. Thus exogenous proteins are hardly expressed after injection of conventional RNA. To circumvent this, we synthesized a long polyadenylated (approximately 250 A) tail to encode RNA with an enhanced yellow fluorescent protein targeted to mitochondria (EYFP-mito), and injected it into mouse oocytes at the germinal vesicle (GV) stage. From this transcript, EYFP-mito was clearly expressed in approximately 80% of oocytes, while scarce expression from a transcript with only 30 A was observed. In strongly expressing oocytes, fluorescence was detected within 1-3 h after RNA injection, increased linearly up to 12 h, and reached a maximum at 12-15 h. The distribution of EYFP-mito matched the staining of mitochondria in these oocytes. About 80% of these oocytes underwent GV breakdown and 60% matured in vitro, comparable to non-expressing or non-RNA-injected oocytes. Some of the oocytes which strongly expressed EYFP-mito remained at the GV stage. Thus, the expression was not always accompanied by meiotic maturation, nor did it suppress the maturation process. Mature oocytes expressing EYFP-mito possessed normal fertilizability associated with intracellular Ca(2+) oscillations, and developed into 2-cell embryos. Thus, polyadenylated RNA is a useful tool applicable to the expression of EYFP-fused functional proteins or of indicator protein probes for studies of mammalian fertilization.

Reparametrization-covariant theory for on-line learning of probability distributions

We discuss the on-line learning of probability distributions in a reparametrization covariant formulation. Reparametrization covariance plays an essential role not only to respect an intrinsic property of "information" but also for pattern recognition problems. We can obtain an optimal on-line learning algorithm with reparametrization invariance, where the conformal gauge connects a covariant formulation with a noncovariant one in a natural way.

Cosecretion of prolactin and growth hormone by dispersed pituitary cells of the adult bullfrog, Rana catesbeiana

The coexistence of prolactin (PRL) and growth hormone (GH) was previously demonstrated in newly hatched bullfrog (Rana catesbeiana) tadpoles, whereas in adult bullfrogs, there were no cells containing both PRL and GH. However, a cell blot assay with enzymatically dispersed adult pituitary cells demonstrated the existence of cells secreting both PRL and GH. The number of cells secreting both PRL and GH was reduced by a protein synthesis inhibitor, cycloheximide, but not by an RNA synthesis inhibitor, actinomycin D. In situ hybridization and immunostaining of intact pituitary glands revealed the existence of GH mRNA in some of the PRL-immunoreactive cells and of PRL mRNA in some of the GH-immunoreactive cells. We propose that dispersion of the pituitary cells triggered the translation of GH mRNA in the PRL cells and/or of PRL mRNA in the GH cells.

Induction of epithelial differentiation and DNA demethylation in hamster malignant oral keratinocyte by ornithine decarboxylase antizyme

The hamster ornithine decarboxylase antizyme (ODC-Az) cDNA was transfected into the hamster malignant oral keratinocyte cell line, HCPC-1. Ectopic expression of ODC-Az resulted in the reversion of malignant phenotypes and alteration of DNA methylation status of CCGG sites. The phenotypes examined include ODC enzymatic activity, doubling time, morphological change, anchorage dependent growth, tumorigenicity in nude mice, induction of epithelial differentiation marker protein (involucrin), and change of cell cycle position. Comparison of CCGG DNA methylation status of the ODC-Az and control vector transfectants revealed a significant increase in demethylation of 5-methyl cytosines (m5C) of CCGG sites in the ODC-Az transfectants. Ectopic expression of ODC-Az gene in hamster malignant oral keratinocytes led to reduce ODC activity and the subsequent demethylation of 5-methyl cytosines, presumably via the ODC/ polyamines/ decarboxylated S-adenosylmethionine (dc-AdoMet) pathways. Our data suggest that ODC-Az shared the same pathway of polyamines/ dc-AdoMet/DNA methyltransferase (DNA MTase). We propose that ODC-Az mediates a novel mechanism in tumor suppression by DNA demethylation and presumably re-activation of key cellular genes silenced by DNA hypermethylation during cancer development. Oncogene (2001) 20, 24 - 33.

[Two cases of the epidermoid on the petrous bone]

Epidermoids known as cholesteatomas, are congenital benign tumors and originate in the embryonic ectoderm. They account for 1.3% of all intracranial tumors. They are often found in the cerebellopontine angle and the paraseller region, but rarely in the petrous portion of the temporal bone. Epidermoids of the petrous bone tend to slowly present progressive facial palsy and hearing disturbance. In this article, two cases of epidermoids involving the petrous bone are reported. A 55-year-old male presented left facial palsy, left hearing disturbance and decreased gustation in the left side of the tongue. MRI revealed a non-enhanced mass on the petrous portion of the left temporal bone, and bone-window CT showed bone destruction in the same region (Case 1). A 71-year-old female was aware of left facial palsy and left hearing loss for 15 years. MRI showed a non-enhanced mass on the petrous bone, and bone-window CT demonstrated extensive bone erosion of the petrous bone and the middle cranial fossa (Case 2). In both cases, total removal was performed via the middle cranial fossa approach. Both tumors existed extradurally and had pressed against the genicurate ganglion of the facial nerve. The facial palsy of the former case recovered 12 months after surgery. We discuss the problems of diagnosis and treatment of epidermoids of the petrous bone.

Axi-vision camera (real-time distance-mapping camera)

The camera described here makes color TV images that include information about the distance between the camera and the objects in the images. This range information is obtained from two images of the same scene taken under different illumination conditions. The camera does not require scanning, multiple camera units, or complicated computation. Range information for each pixel is acquired fast enough to keep up with the video rate of a TV camera. We describe various operational features and technical specifications such as ranging errors as well as the results of experimental investigations of the dependence on the color and reflectivity of the objects, of the sensitivity to interference from external light, and of the effects of the movement of the objects.

Factors in neurological deterioration and role of surgical treatment in lumbosacral spinal lipoma

The purpose of this study was to determine factors that might be involved in neurological deterioration and the role of surgical treatment in patients with lumbosacral spinal lipoma. Pre- and postoperative courses of 34 patients were retrospectively analyzed. The age at surgery ranged from 1 month to 47 years. The records of preoperative neurological status indicated that older patients had more severe deficits, while all 8 asymptomatic patients were under 5 years of age. Motor deficits were noted in 9 patients, in 7 of whom the lipoma extended cranially beyond the L5 level. Transitional-type lipomas were accompanied by more severe deficits (asymptomatic 1, symptomatic 17) than other types (asymptomatic 7, symptomatic 9). Postoperative follow-up periods ranged from 5 months to 13 years. During these periods, 7 of the 8 asymptomatic patients remained neurologically intact. Nine of the 26 symptomatic patients improved. Age, extension of the lipoma in the spinal canal and type of lipoma will influence the preoperative neurological status of the patients. Early untethering surgery is recommended in patients with large lipomas extending beyond the L5 level.

Extrusion polymerization: catalyzed synthesis of crystalline linear polyethylene nanofibers within a mesoporous silica

Crystalline nanofibers of linear polyethylene with an ultrahigh molecular weight (6,200,000) and a diameter of 30 to 50 nanometers were formed by the polymerization of ethylene with mesoporous silica fiber-supported titanocene, with methylalumoxane as a cocatalyst. Small-angle x-ray scattering analysis indicated that the polyethylene fibers consist predominantly of extended-chain crystals. This observation indicates a potential utility of the honeycomb-like porous framework as an extruder for nanofabrication of polymeric materials.

Enhancement by proopiomelanocortin-derived peptides of growth hormone and prolactin secretion by bullfrog pituitary cells

Corticotrophs in the bullfrog (Rana catesbeiana) are situated mainly in the rostral region of the anterior lobe of the pituitary gland, which receives its blood supply primarily from the portal vessel. On the assumption that the proopiomelanocortin (POMC)-derived peptides released into the pituitary circulation may influence the function of other pituitary cells situated downstream, the effects of three POMC-derived peptides, namely, N-terminal peptide of POMC (NPP), adrenocorticotropic hormone (ACTH), and joining peptide (JP), on the secretion of growth hormone (GH) and prolactin (PRL) by bullfrog dispersed anterior pituitary cells were examined. NPP and ACTH, but not JP, stimulated the release of GH and PRL in a concentration-dependent manner. It was also found that ACTH1-17, but not alpha-melanocyte-stimulating hormone, was effective in enhancing GH and PRL release. A marked difference between the response to NPP and ACTH and the response to thyrotropin-releasing hormone employed as a reference secretagogue in terms of the time required for stimulating the release of GH and PRL was noted. Northern blot analysis of GH and PRL mRNA levels and radioimmunoassay for GH and PRL in the cultured cells revealed that ACTH increases the syntheses of both pituitary hormones as well. The possibility that NPP and ACTH act on neighboring cells to maintain their overall secretory function is discussed.

Evaluation of allergenic potential of low-molecular compounds by mouse popliteal lymph node assay

In the present study, the correlation between mouse PLNA results and those obtained from GP-PCA and from GP-ASA reactions for sodium 2,4,6-trinitrobenzenesulfonate dihydrate (TNBS), penicillin G and cephalothin was investigated. Next, various drugs were tested using the mouse PLNA to study whether PLN reactivity could be related to the potential of the compounds to induce allergic and autoimmune disorders in humans. The parameter of the PLNA was determined by the PLN cellularity index in BALB/c and A/J mice treated with a single subcutaneous injection of compounds. Hartley guinea pigs were immunized subcutaneously with the compounds without adjuvant, and then the GP-PCA and GP-ASA reactions were assessed. The examinations using mice and guinea pigs showed that mouse PLN responses to TNBS, penicillin G and cephalothin correlated with the allergenicity responses obtained in the GP-PCA reaction to three compounds. In the mouse PLNA, ten drugs considered to be well-known inducers of allergic side-effects in humans (i.e., penicillin G, cephalothin, ampicillin, carbenicillin, cefazolin, cefotaxime, streptomycin, 4-aminoantipyrine, chlorhexidine and sulfamethoxazole) caused increases in PLN cellularity indices as well. These results indicate that the PLNA may be useful as a short-term and simple test system for detecting low-molecular drugs exhibiting allergenicity potential.

Sex differences in immune responses to cephalothin in guinea pigs

Guinea pigs of two strains, outbred Hartley and inbred Strain 2, were immunized subcutaneously with cephalothin (CET, 20 mg/body) alone, without adjuvant. Immune responses to the antibiotic were assessed by guinea-pig passive cutaneous anaphylaxis (GP-PCA) and active systemic anaphylaxis (GP-ASA) reactions. The immune response to CET in the female Hartley guinea pigs was higher than that in the males. In contrast, no difference in response to CET in Strain 2 guinea pigs was observed between males and females. These results suggested that female Hartley guinea pigs possessing a higher response should be employed in antigenicity studies involving the beta-lactam antibiotics.

Differences in immune responses to antibiotics in three guinea-pig strains

The present experiments were undertaken to clarify the differences in humoral immune response to two beta-lactam antibiotics, benzylpenicillin potassium (PcG) and cephalothin sodium (CET), in guinea-pig strains. Guinea pigs of three different strains, Hartley, Strain 2 and Strain 13, were immunized subcutaneously with PcG (10 mg/body) 1 or 3 times a week, 10 times in total, or with CET (20 mg/body) 3 times a week, 12 times in total. Humoral immune responses to the two antibiotics were assessed by passive cutaneous anaphylaxis (PCA) and active systemic anaphylaxis (ASA) reactions. The relative intensities of the responses to PcG and CET detected by PCA reaction were Hartley > Strain 2 > Strain 13. On the other hand, Hartley and Strain 13 guinea pigs displayed high responses to the two antibiotics by ASA reaction, and Strain 2 exhibited a relatively low response. Based on these results, it was clarified that the Hartley strain, which is the most common strain used in ordinary allergenicity tests, showed the highest response to the two antibiotics tested in PCA and ASA reactions.

Stimulation by proopiomelanocortin-derived peptides of LH release by bullfrog dispersed anterior pituitary cells

Labeling and immunoprecipitation experiments confirmed that three proopiomelanocortin (POMC)-derived peptides, the N-terminal peptide of POMC (NPP), joining peptide (JP) and adrenocorticotropic hormone (ACTH), were released by the bullfrog (Rana catesbeiana) anterior pituitary. The effects of these three peptides on luteinizing hormone (LH) release by bullfrog dispersed anterior pituitary cells were studied. NPP and ACTH, but not JP, enhanced LH release concentration-dependently. Approximately 6 hr elapsed before the gonadotrophs responded to NPP and ACTH by releasing LH, whereas their response to human GnRH (hGnRH) was faster, suggesting that the modes of action of these two peptides and hGnRH differ. These results raise the possibility that NPP and ACTH act as paracrine factors in the bullfrog pituitary to enhance LH release either directly or indirectly.

Enhancement by prolactin of the GnRH-induced release of LH from dispersed anterior pituitary cells of the bullfrog (Rana catesbeiana)

The response of enzymatically dispersed anterior pituitary cells of the bullfrog (Rana catesbeiana) to gonadotropin-releasing hormone (GnRH) was studied by monitoring the release of luteinizing hormone (LH) into the culture medium. The cells responded to GnRH by releasing LH according to the incubation time and to the GnRH concentration. The responsiveness to GnRH became less conspicuous as the cell density was reduced. Addition of prolactin (PRL) to the medium enhanced the responsiveness to the secretagogue, and addition of antiserum against PRL lowered the responsiveness to a certain extent. Immunohistochemical studies of sectioned pituitaries revealed that PRL cells most frequently located in contact with LH cells. The possibility that PRL acts directly on gonadotrophs to enhance their responsiveness to GnRH was suggested.

Differences in immune responses to a low-molecular compound in three guinea-pig strains

The present experiments were undertaken to clarify the differences in humoral and cellular immune responses to a low-molecular compound, sodium 2,4,6-trinitrobenznnesul fonate dihydrate (TNBS) in guinea-pig strains. Guinea pigs of three different strains, Hartley, Strain 2 and Strain 13, were immunized subcutaneously with TNBS (3 mg/body) 2 or 3 times a week, 9 times in total. Humoral immune responses to TNBS were assessed by passive cutaneous anaphylaxis (PCA) and Arthus reaction, and cellular immune response was assessed by delayed-type hypersensitivity (DTH). Hartley guinea pigs showed high humoral immune responses to TNBS, whereas Strain 2 and 13 guinea pigs showed low responses. Strain 2 guinea pigs displayed high cellular immune response to TNBS, and Strain 13 displayed low cellular immune responses. These results suggest that the pattern of humoral immune response to TNBS does not correlate with that of the cellular immune responses to TNBS for Strain 2 and Hartley guinea pigs.

A new sigma factor homolog in a cyanobacterium: cloning, sequencing, and light-responsive transcripts of rpoD2 from Microcystis aeruginosa K-81

We isolated an rpoD2 gene encoding the potential sigma factor of RNA polymerase from the cyanobacterium Microcystis aeruginosa K-81, which can perform photosynthesis. The deduced amino acid sequence of RpoD2 (sigmaA2) exhibits extensive homology to other eubacterial RpoD proteins. This gene possessed multiple 5'-end transcripts, expressed specifically under light (P(L)), dark (P(D)), or constitutively light/dark (P(C)) conditions during exponential cell growth.

Cloning, sequencing and characterization of the gene encoding a principal sigma factor homolog from the cyanobacterium Microcystis aeruginosa K-81

We cloned and sequenced the rpoD1 gene of Microcystis aeruginosa K-81, a unicellular colony-forming cyanobacterium that can perform photosynthesis involving light-responsive gene expression. The deduced amino acid sequence of RpoD1 exhibited extensive homology to the other eubacterial principal sigma factors. Primer extension and Western blot analyses revealed that the rpoD1 gene, which encodes a principle sigma factor homolog, had two transcription start points, P1 and P2. These transcripts, and the corresponding protein, constitutively appeared in M. aeruginosa, irrespective of light or dark conditions.

The rpoD1 gene product is a principal sigma factor of RNA polymerase in Microcystis aeruginosa K-81

We performed molecular characterization of the RpoD1 protein encoded by the rpoD1 gene isolated from a cyanobacterium, Microcystis aeruginosa K-81. The deduced amino acid sequence (416 aa, 48,871 Da) of RpoD1 exhibited extensive similarity to those of proteins of the eubacterial RpoD family (Escherichia coli sigma 70 homologs). We overproduced and purified RpoD1 (54 kDa) from E. coli. Biological and biochemical analyses suggested that RpoD1 has a function homologous to that of E. coli sigma 70 as follows: (i) the RpoD1 protein complemented an rpoD mutant of E. coli strain YN543 (rpoD285) and (ii) the heterologous RNA polymerase holoenzyme reconstituted from the E. coli core enzyme and recombinant RpoD1 was specifically transcribed from E. coli promoters. Furthermore, Western blot analysis with antiserum against Synechococcus sp. strain PCC 7942 RpoD1 (a principal sigma factor of the sigma 70 type) indicated that M. aeruginosa K-81 RpoD1 (sigma A1) is the principal sigma factor, which is a major component of the sigma subunit on exponential cell growth.

Phase II study of DTIC, ACNU, and vincristine combination chemotherapy for supratentorial malignant astrocytomas

This phase II clinical study evaluated the use of 5-(3-3'-dimethyl-1-triazeno)imidazole-4-carboxamide (DTIC) pretreatment to reduce cellular resistance and enhance the antitumor effects of chloroethyl nitrosoureas in 32 patients with supratentorial malignant gliomas, including 13 anaplastic astrocytoma and 19 glioblastoma multiforme. All patients received a total dose of 50-65 Gy radiation therapy after surgery. Chemotherapy consisted of DTIC (1 mg/kg) on days 1-5, 1-(4-amino-2-methyl-5-pyrimidinyl)methyl-3-(2-chloroethyl)-3-nitrosourea hydrochloride (2 mg/kg) on day 5, and vincristine (0.02 mg/kg) on days 1 and 15 every 5 weeks. One patient achieved complete response and 12 patients showed partial response. Median survival time was 18 months and median time-to-progression was 11 months. No significant toxicity was encountered. There was no significant benefit of this pretreatment to combination chemotherapy when compared with previous results. This study does not support a further role for DTIC as a depleter of O6-alkylguanine deoxyribonucleic acid alkyltransferase activity preceding chloroethyl nitrosourea-based chemotherapy.

The sre gene (ORF469) encodes a site-specific recombinase responsible for integration of the R4 phage genome

The sre gene (ORF469) of the R4 phage encodes a protein similar to the resolvase-DNA invertase family proteins. Insertional gene disruption of sre prevented a lysogen from entering the lytic cycle, implying that Sre protein is a site-specific recombinase needed for excision of the R4 prophage genome (M. Matsuura, T. Noguchi, T. Aida, M. Asayama, H. Takahashi, and M. Shirai, J. Gen. Appl. Microbiol. 41:53-61, 1995). To determine whether this sre gene is also necessary for the integration reaction, we studied its function by integration plasmid analysis. When deletions, frameshifts, and site-directed mutations that caused an amino acid substitution of Ser-17 for Ala were introduced into the sre structural gene, transformation efficiency of Streptomyces parvulus 2297 with these plasmid DNAs was severely reduced. However, an adenine insertion just before the possible initiation codon of the sre gene did not significantly decrease the efficiency. These data suggest that the Sre protein is a site-specific recombinase responsible for integration of the R4 phage genome.

Highly repetitive sequences and characteristics of genomic DNA in unicellular cyanobacterial strains

Microcystis aeruginosa (Synechocystis) is a unicellular cyanobacterium that performs oxygenic photosynthesis. We found two novel sets of repetitive sequences, A (REP-A) and B (REP-B), on the M. aeruginosa K-81 genomic DNA, which consisted of distinct motifs of tandem repeated sequences located in the up- and downstream regions of the orf1 structural gene, respectively. Genomic Southern hybridization revealed multicopies of REP-A and -B on the genome. Furthermore, genomic Southern blots of cyanobacteria species with the REP-A and -B probes revealed that different hybridization signals appeared on the genomic DNAs of all 12 Microcystis strains, but no signal appeared on those of Synechocystis sp. PCC 6803, Synechococcus sp. PCC 7942, and Anabaena sp. PCC 7120.

Immunohistochemical analysis of giant cell glioblastoma

Giant cell glioblastoma (GCG) is one of a group of rare tumors in which the cell population is abnormally large and includes multinucleated cells of gigantic sizes. Immunohistochemical studies were performed on four GCG cases and found that all giant cells and/or tumor cells were positive for glial fibrillary acidic protein (GFAP), S-100 protein, and vimentin, thus verifying the tumor's glial origin. The nuclei of multinucleated giant cells of three adult cases were frequently immunostained for proteins expressed during the cell cycle (proliferating cell nuclear antigen (PCNA) and Ki-67), thereby demonstrating the proliferative capacity of these cells. By contrast, those of a 12 year old girl expressed these cell cycle markers rather infrequently. Alpha I-antitrypsin was detected with relatively high frequency in the giant cells, and its presence may explain their bizarre sizes and pericellular reticulin fiber formation. A literature review of 32 cases revealed that the GCG that occurs preferentially in young girls is a type of pleomorphic xanthoastrocytoma. By contrast, GCG in adult males has the same age incidence as ordinary glioblastomas and, as these, expresses high levels of cell cycle-related proteins. Thus, GCG, which is subclassified morphologically as ordinary glioblastoma, has distinct biological and clinical characteristics, with that in children requiring re-evaluation because of its similarities to pleomorphic xanthoastrocytoma.

Antiproliferative effect of tumor necrosis factor-alpha on human glioblastoma cells linked with cell cycle arrest in G1 phase

The effects of tumor necrosis factor-alpha (TNF) on proliferation and cell cycle alterations in human malignant glioma cell lines, SF-188 and LN-382, were investigated by flow cytometry with the bromodeoxyuridine-propidium iodide dual staining technique. Low concentrations of TNF (1-100 U/ml) suppressed the growth of SF-188 assessed by cell count, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide assay, and thymidine incorporation assay, but not that of LN-382. After TNF treatment, the percentage of SF-188 cells in the G0/G1 phase increased, while the percentage of cells in the S phase decreased. LN-382 cells did not show any marked change in cell kinetics. TNF arrests certain human glioma cells in the G0/G1 phase resulting in reduction of deoxyribonucleic acid synthesis in the subsequent S phase, suppressing the proliferation pathway.

Fibronectin biosynthesis in endothelial regeneration after intimal injury

In this experiment, we sought to identify the major fibronectin (FN) synthesizing cells, the source of FN production, and the role of FN in intimal regeneration. In rats in which vascular endothelial denudation had been induced, serial morphologic changes after intimal injury were studied by light and electron microscopic examination using immunohistochemical techniques and in situ hybridization. At 2 weeks after intimal injury, regenerated endothelial cells had pleomorphic cytoplasm and loose cellular junctions. Immunohistochemically, factor VIII-related antigen was localized in the regenerated endothelial cells, and immunoreaction products of FN were increased in the thickened neointima. Ultrastructurally, FN was localized in the proliferated endoplasmic reticulum of regenerated endothelial cells in the intima, while the alpha 5 subunit of alpha 5 beta 1 integrin, one of the fibronectin receptors, was localized in the plasma membrane and increased endoplasmic reticulum of regenerated endothelial cells. FN mRNA was localized in a large number of regenerated endothelial cells (87.2 and 89.8%) by in situ hybridization at 2 and 4 weeks after intimal injury. These findings indicate that FN may mainly contribute to endothelial cell functions such as spreading and adhesion in the regenerative stage.

Process of basement membrane re-formation after intimal denudation

During re-endothelialization after intimal denudation induced by balloon catheter in the rat aorta, re-formation of the basement membrane (BM) was examined in samples taken 15 min, 3, 7, 14, 21 and 28 days after the balloon-induced injury. Although the luminal surface of the aortic wall was covered by round-shaped regenerating endothelial cells (ECs) by 7 days after intimal denudation, no continuous BM structure was detectable until 21 days. Periodic acid-thiosemicarbazide gelatin-methenamine silver (PATSC-GMS) staining for electron microscopy and immunostaining of type IV collagen and laminin demonstrated the accumulation of BM components underneath the regenerating ECs after 14 days. The expression of type IV collagen mRNA was revealed in regenerating ECs by in situ hybridization. A continuous BM structure first appeared 21 days after intimal denudation and was almost complete by 28 days. Simultaneously, the regenerating ECs flattened and attached more closely to the BM than in earlier phases. In conclusion, we consider that the regenerating ECs produce the BM components and suggest that reorganization of the newly formed BM is important in the process of differentiation of regenerating ECs.

Characteristics of DNA and multiple rpoD homologs of Microcystis (Synechocystis) strains

The base compositions of DNAs from nine Microcystis strains, as determined by high-performance liquid chromatography, were 41 to 42 mol% G+C. Chromosomal DNAs derived from these strains were found to be extremely resistant to many restriction endonucleases, and a restriction analysis revealed the presence of a dam-like methylase or both dam- and dcm-like methylases in all of the strains examined. Genomic Southern hybridization in which a synthetic oligonucleotide probe (rpoD probe) was used showed that members of the genus Microcystis might have multiple rpoD homologs, and the hybridization signal patterns observed with the DNAs of Microcystis aeruginosa strains were different from each other.

Human glioblastoma cells produce granulocyte-macrophage colony-stimulating factor in vitro, but not in vivo, without expressing its receptor

Granulocyte-macrophage colony-stimulating factor (GM-CSF) production and receptor expression by human glioblastomas was studied. Enzyme-linked immunosorbent assay showed four of 10 glioblastoma cell lines spontaneously released GM-CSF (2.9-9.2 pg GM-CSF protein/ml culture medium), which was enhanced by stimulation with tumor necrosis factor-alpha (TNF) (10 U/ml) up to 410 pg/ml. TNF also induced secretion of GM-CSF by another cell line. Northern blot analysis identified increasing GM-CSF gene expression by cells following TNF stimulation. However, no GM-CSF protein was detectable in the cerebrospinal fluid of three malignant glioma patients. Intratumoral administration of TNF in the patients also failed to stimulate GM-CSF levels in the cerebrospinal fluid. A binding assay using flow cytometry with biotinylated GM-CSF and Scatchard analysis using 125I-labeled GM-CSF failed to demonstrate GM-CSF receptor expression on the 13 cell lines. Exogenous GM-CSF stimulation had no effect on production of prostaglandin E2, interleukin-6, or interleukin-8 by glioma cells. Human glioblastoma cells secrete GM-CSF without expressing the receptor in vitro, but there was no evidence of GM-CSF production in vivo.

Dystrophic axonal formation (spheroid body) in central neurocytoma--case report

A 30-year-old female presented with a central neurocytoma manifesting as positional headache. Magnetic resonance imaging showed a large calcified mass in the right lateral ventricle. The tumor was completely removed surgically. Light microscopy showed a linear arrangement of well-defined cells (beaded-string pattern) containing small round nuclei with abundant perikarya. A perinuclear halo reminiscent of oligodendroglioma was prominent in some cell groups. The tumor was entirely amitotic and free of atypia. Large, plump spheroid bodies lacking nuclei but containing coarse brown pigments were present among the tumor cells. The tumor cells were immunoreactive to neuron-specific enolase and synaptophysin but not glial fibrillary acidic protein or neurofilament. The ultrastructure of the tumor cells included abundant spheroid bodies containing secretory granules around neurons, indicating a dystrophic or aborted process of neuronal differentiation rather than a completely-differentiated central neurocytoma.

Desmoplastic infantile ganglioglioma--case report

A desmoplastic infantile ganglioglioma occurred in a 5-month-old boy, manifesting as delayed psychomotor development. Computed tomography showed a large cystic mass involving the left occipitoparietal lobes. The tumor was totally removed. He has survived for 13 years without tumor recurrence. Histological examination disclosed marked desmoplasia intermixed with mature-looking ganglion cells, neoplastic glial cells, and small, immature round cells. These clinical and histological features enabled the diagnosis of desmoplastic infantile ganglioglioma.

Responses of human glioblastoma cells to human natural tumor necrosis factor-alpha: susceptibility, mechanism of resistance and cytokine production studies

Responses and susceptibility of 14 human glioblastoma cell lines to human natural tumor necrosis factor-alpha (TNF) were studied in vitro. Susceptibility of glioblastoma cells to TNF varied in experimental conditions applied. Most of glioblastoma cell lines were resistant to cytotoxic activity of TNF in a MTT assay at concentrations below 16 U/ml for 72 h exposure. However, TNF at higher dose, in prolonged exposure and against low density of target cells was antiproliferative for certain glioblastoma cultures. TNF exposure at 10 U/ml for 48 h suppressed DNA synthesis in 9 of 14 glioblastoma cultures, but increased in 3 cultures. In addition, colony forming assay showed anti-clonogenic activity of TNF in 5 of 6 glioblastoma cell lines tested. In spite of their low susceptibility to TNF, glioblastoma cells well responded to TNF stimulation at low dose (10 U/ml) for a short period in the absence of cell damage. Productions of Interleukin-6 (IL-6), IL-8-like activity, granulocyte-macrophage colony stimulating factor (GM-CSF), prostaglandin E2 (PGE2) and manganous superoxide dismutase (Mn-SOD) were enhanced or induced by the low-dose TNF stimulation. Mn-SOD, a protein protective against oxidative cell damage, was well induced in time- and dose-dependent manner, however did not correlate with TNF resistance. Whereas the levels of PGE2 in TNF-susceptible cell lines, H-4 and SF-188, were higher than those of other lines. In conclusion, most of glioblastoma cells are resistant to TNF cytotoxic effects, but highly responsive to TNF stimulation. Its effect on glioblastoma cells appears to modulate cell differentiation rather than to kill the cells.

Endocrine functions in children with suprasellar germinoma

Clinical manifestations and endocrine functions were evaluated in 17 children with suprasellar germinoma. Polyuria and growth retardation were the most common initial symptoms. Physical and neurological examinations revealed diabetes insipidus in 17, growth retardation in five, and visual disturbance in three of the patients. Assessment of hypothalamic-pituitary function before treatment revealed pituitary deficits in all patients involving growth hormone, thyroid-stimulating hormone, luteinizing hormone, follicle-stimulating hormone, and adrenocorticotropic hormone. These pituitary dysfunctions persisted after tumor remission due to radiation therapy. These results indicate that children with suprasellar germinoma need long-term hormone replacement therapy to prevent growth retardation, thyroid dysfunction, and delayed secondary sexual development.

[Expression of type III and IV procollagen, prolyl 4-hydroxylase mRNAs in fibrotic human liver]

In situ localization of type III, IV procollagen and prolyl 4-hydroxylase mRNAs were examined to clarify the collagen production in fibrotic human liver. These mRNAs were localized in hepatocytes and mesenchymal cells in the areas of liver fibrosis. In alcoholic liver disease, the expression was promoted, and positive cells were diffusely observed in nodules. These results suggest that hepatocytes along with mesenchymal cells produce collagens, and correlate with pericellular fibrosis and sinusoidal capillarization in alcoholic liver disease.

Vacuolated meningioma with secretory features: a case report

We report a case of meningioma with secretory features in a 47-year-old woman. The left frontal tumor mass had already eroded the overlying bone at the time of presentation. When respected, the mass showed a gelatinous appearance. Histologically, marked vacuolar change was seen in the stroma. Whorls, psammoma bodies, and pavement arrangement of nuclei were also noted. Periodic acid-Schiff stain revealed cytoplasmic granules, which were digested with diastase. Alcian blue diffusely stained the cytoplasm of the tumor cells. Electron microscopy showed numerous small vacuoles and cored vesicles in the cytoplasm. Glycogen granules were poorly observed. These features indicate the mild secretory nature of this vacuolated meningioma.

Cellular and cytokine responses of the human central nervous system to intracranial administration of tumor necrosis factor alpha for the treatment of malignant gliomas

To elucidate the role of tumor necrosis factor alpha (TNF alpha) as a biological response modifier, we studied cellular and cytokine responses of the central nervous system to TNF alpha administered intracranially in a phase I clinical trial for patients with malignant gliomas. Six patients received injections of TNF alpha (1.25 x 10(3)-10 x 10(3) U/injection) into the tumor cavities, and regional fluids (RF) and lumbar cerebrospinal fluids (CF) were serially sampled before and after the injections. Recruitment of neutrophils occurred, mostly peaking 8 h after TNF alpha injection, and fewer numbers of CD4+ T cells and monocytes/macrophages migrated, subsequently peaking at 24 h. The CF leukocytosis persisted for 48 h and was associated with an increased level of neutrophil chemotactic activity in the CF. This neutrophil chemotactic activity was attributed to interleukin-8 (IL-8) by HPLC. The level of IL-6 activity in the CF and RF consistently increased; beginning 2 h after TNF alpha injection and reaching the maximum between 8 h and 12 h. It returned to the basal level within 48 h. IL-1 beta was detected in the CF of three patients, its level peaking at 8 h. Prostaglandin E2 also increased after injection of TNF alpha, peaking between 4 h and 12 h and then gradually decreasing. Transforming growth factor beta was found in all cases tested and one patient showed a significant change after TNF alpha injection. IL-2 activity, interferon alpha (INF alpha) activity, IFN beta, and granulocyte/macrophage-colony-stimulating factor were not detected in the CF or RF. In conclusion, TNF alpha is biologically effective in inducing migration of immune cells and generating multiple cytokine responses in the human central nervous system.