Differential regulation of catalytic and non-catalytic trkB messenger RNAs in the rat hippocampus following seizures induced by systemic administration of kainate

Ribonuclease protection analysis and quantitative in situ hybridization histochemistry were used to investigate the coordination and regional expression of catalytic and non-catalytic trkB messenger RNAs in the adult rat hippocampus following systemic kainate-induced seizures. Changes in trkB expression were compared with the messenger RNA expression of its neurotrophic ligands, brain-derived neurotrophic factor and neurotrophin-3. TrkB messenger RNA expression was increased in the dentate granule cells at 1-4 h following the onset of seizures, and returned to control levels 16-24 h thereafter. In addition, seizures also induced expression of trkB messenger RNA in putative non-neuronal cells at four to seven days in the molecular layer of the dentate gyrus and the stratum lacunosum moleculare of the CA1 region. Hybridization with probes specific for the non-catalytic trkB receptor and the catalytic trkB receptor revealed that the increases at four and seven days in the molecular layers of the hippocampus reflected an up-regulation of only the non-catalytic form of the receptor. Furthermore, the neuronal increases observed 1-4 h were due to an up-regulation of both trkB TK- and trkB TK+ messenger RNAs. It was established that systemic administration of kainate increased brain-derived neurotrophic factor messenger RNA levels in the pyramidal and granule cell regions of the hippocampus 1-4 h following the onset of behaviorally manifested seizure activity. Early changes in neuronal expression of trkB TK- and trkB TK+ messenger RNA paralleled changes in brain-derived neurotrophic factor messenger RNA in the dentate granule cell and CA1 pyramidal cell layers, but not in the CA3 subregion. These data suggest that concomitant regulation of brain-derived neurotrophic factor and its cognate receptor may play a role in the selective vulnerability of hippocampal subregions to kainate-induced neuropathology. Furthermore, these data suggest a dual function for trkB receptor expression in the hippocampus following kainate-induced seizures, possibly related to both the plastic and degenerative consequences of seizure induction by kainate.

Fatal Epstein-Barr virus-associated lymphoproliferative disorder in childhood

OBJECTIVE

We report five childhood cases of fatal Epstein-Barr virus-associated lymphoproliferative disorder to determine their immunopathologic and immunogenotypic features.

DESIGN

Clinicopathologic features are described, using clinical, histologic, immunophenotypic, and genotypic examinations.

SETTING

Autopsy cases were performed at Nagoya and Tsukuba university hospitals, Japan.

RESULTS

Infiltrating lymphocytes, which were positive for the EBV genome by in situ hybridization, were polymorphic and showed polyclonal immunoglobulin staining in all five cases. Two cases, however, showed genetic clonality of EBV termini. In one case, the clonality was observed only in the spleen, and in the other case, clonal rearrangement of the JH gene was also found. The former case showed none of the morphologic features of neoplasia and presented a morphology similar to virus-associated hemophagocytic syndrome. In the latter case, infiltrating lymphoid cells were much less polymorphous, and nodular masses of the lymphoid cells in colon and lung specimens were observed.

CONCLUSION

We suggest that some polyclonal EBV-associated lymphoproliferative disorders develop into polymorphic, but genotypically monoclonal, lymphoproliferative disorders.

The effect of protein kinase C stimulator and inhibitor on cochlear potentials in the guinea pig

To determine a possible role of protein kinase C (PKC) in the cochlear, the effects of a PKC stimulator (phorbol-12-myristate-13-acetate; PMA), an inactive analogue of PKC stimulator (4 alpha-phorbol-12,13-didecanoate; 4 alpha-PDD) and a PKC inhibitor (D-sphingosine) on cochlear potentials were examined in the guinea pig. The perilymphatic perfusion with PMA (3 x 10(-6) M) produced an increase in compound action potential (CAP) amplitude and no change in N1 latency, the amplitudes of negative summating potential (-SP), cochlear microphonics (CM) and endocochlear potential (EP). The perfusion with 4 alpha-PDD (3 x 10(-6) M) did not change the sound-evoked cochlear potentials and the EP. The perfusion with D-sphingosine (10(-5) M) produced a decrease in CAP amplitude and no change in N1 latency and the amplitudes of -SP, CM and EP. The results suggest that PKC may be involved in the mechanism underlying the CAP generation.

Changes in IgA and metals in serum and urine of human volume hypertension

In this study, disturbance of immune response as a pathogenic mechanism for human volume hypertension was investigated and compared to nephritis in its correlation with the metals such as zinc, iron and aluminum as environmental factors. Urinary gamma-GTP excretions in patients with nephritis or hypertension were higher than in healthy people, whereas the plasma renin activity in these patients were lower on the average than in healthy individuals. Hypertensive patients participating in this study were diagnosed as the volume hypertension type from our clinical and other results. The serum IgM and IgA levels in renal patients showed a tendency to be lower than in the healthy people used as control. Urinary IgA excretion in hypertensive patients was increased in association with increasing excretions of aluminum and/or iron into urine. The values of regression coefficients in the urine samples for aluminum and iron vs. IgA, respectively, were very high at r = 0.900 (n = 9, p < 0.05) and 0.736 (n = 9, p < 0.05). These correlations were shown to be very useful indicators in diagnosing volume hypertension. Moreover, hypertensive patients in this study were demonstrated to have a high regression coefficient (r = -0.702, n = 7; p < 0.05) for calcium vs. renin in the serum. In the hypertension, augmentation of serum calcium significantly decreased plasma renin activity.

Structure-cytotoxicity relationship of tilivalline derivatives

Tilivalline (TV) possesses a pyrrolo[1,4]benzodiazepine nucleus and an indole substituent in its structure, and is cytotoxic toward mouse leukemia L1210 cells. In order to obtain more effective compounds, we have previously synthesized a variety of TV analogues. In this study, the cytotoxicity of these compounds has been evaluated. Among the compounds tested, the 11-beta-cyano compound, a TV analogue bearing the cyano group instead of the indole group, is approximately 100 times more cytotoxic than TV itself. The alpha-epimer of this cyano compound has about one-hundredth the cytotoxicity of the 11-beta-cyano compound. Structure-cytotoxicity relationships are discussed, including the effects of stereoisomers (alpha and beta) at the 11 position and substitution at the benzene moiety of TV.

Role of endolymphatic anion transport in forskolin-induced Cl- activity increase of scala media

To determine the role of anion transport in the forskolin-induced Cl- increase of scala media (SM), effects of forskolin on the EP (endocochlear potential) and Cl- activity (ACl) in SM were examined with double-barrelled Cl(-)-selective microelectrodes. The experiments were carried out on guinea pig cochleae, using a few anion transport inhibitors: IAA-94 for a Cl- channel blocker, bumetanide (BU) for an Na+/K+/2Cl- cotransport blocker, and SITS and DIDS for Cl-/HCO3- exchange blockers. The application of forskolin (200 microM) into scala vestibuli (SV) caused a 20 mEq increase of endolymphatic ACl and a 15 mV elevation of EP, and IAA-94 with forskolin completely abolished these responses. Although each application of BU, SITS or DIDS did not completely suppress EP elevation, the concurrent application of these inhibitors completely suppressed EP with endolymphatic ACl increase. The results indicate the involvement of Cl- channels, Na+/K+/2Cl- cotransport and Cl-/HCO3- exchange in forskolin-induced increase of ACl and EP. The role of adenylate cyclase activation and Cl- transport in endolymph homeostasis was discussed.

Lesion-induced sprouting of commissural/associational axons and induction of GAP-43 mRNA in hilar and CA3 pyramidal neurons in the hippocampus are diminished in aged rats

Removal of synaptic connections following a partial deafferentation lesion results in a sprouting of remaining afferents that terminate near the denervated area. However, while the ability to form new synapses in response to injury has been reported in both young and aged rats, previous studies have suggested that the injury-induced response in the hippocampus of aged rats may be delayed and/or not as extensive as compared to young adults. Given that growth associated proteins are central for the regulation of neurite outgrowth during both development and regeneration, we were interested in determining if the magnitude and time course of the sprouting response of hippocampal neurons to deafferentation might correlate with induction of growth associated proteins and whether these parameters could be modulated with age. For our studies we used the Holmes fiber stain to determine the expansion of the C/A fiber plexus following denervation and compared the time course of the sprouting response with that observed by in situ hybridization for the neurite outgrowth proteins, growth associated protein-43 (GAP-43), superior cervical ganglion-10 (SCG-10), and neurofilament-68 (NF-68) at various time points after the lesion for each age group. We found that the commissural/associational (C/A) fiber plexus expanded by 45% in young adult rats at 30 and 45 d postlesion and was accompanied by a significant increase in expression of GAP-43 mRNA in both ipsilateral and contralateral hilar and CA3 pyramidal neurons, the cell bodies of origin for the C/A pathway. In contrast, a dampened sprouting response was observed in aged rats at all time points postlesion and coincided with a lack of induction of any of the growth-associated proteins. These results suggest that GAP-43 is involved in outgrowth of C/A axons in the hippocampus in response to a partial deafferentation lesion. However, factors that stimulate neurite outgrowth and upregulate GAP-43 mRNA in response to a partial deafferentation lesion diminish with age.

Genetic dissection of susceptibility to radiation-induced apoptosis of thymocytes and mapping of Rapop1, a novel susceptibility gene

Genetic dissection of susceptibility to radiation-induced apoptosis of thymocytes was performed by counting dead cells in histologically processed thymuses after 0.5 Gy of whole-body X-irradiation, using recombinant congenic (CcS/Dem) strains derived from inbred mouse strains BALB/cHeA (susceptible) and STS/A (resistant). A high (8/20) number of strains with lower dead cell scores than BALB/cHeA among CcS/Dem recombinant congenic strains (RCS), which contain 12.5% of STS/A genome in the genetic background of BALB/cHeA strain, indicates that the difference between BALB/cHeA and STS/A is caused by several genes and that susceptibility probably requires BALB/cHeA alleles at more than one locus. Similar results were obtained with CXS/Hg recombinant inbred (CXS/Hg) strains. Analysis of F2 hybrids between BALB/cHeA and CcS-7, one of the CcS/Dem strains that showed lower dead cell scores than BALB/cHeA, demonstrated that a novel gene (Rapop1, radiation-induced apoptosis 1) controlling susceptibility to radiation-induced apoptosis in the thymus is located in the proximal region of mouse chromosome 16.

[Successful treatment of acute myelomonocytic leukemia developed from MDS with cytarabine ocfosfate (SPAC)]

A 65-year-old female with acute myelomonocytic leukemia (AMMoL) developed from myelodysplastic syndrome (MDS), successfully treated with cytarabine ocfosfate (SPAC) is reported. Ubenimex, calcitriol and corticosteroid had a minor effect on her MDS. Since she had severe anemia and congestive heart failure on developing leukemia, she was treated with oral administration of SPAC, a cytidine deaminase resistant derivative of Ara-C. After the second course of SPAC (200 mg/day, for 14-28 days), marked erythroid bursts were found and she entered complete remission. The samplings of SPAC and its metabolites of SPAC were investigated in 2 cases including this case, but there seemed to be no relation between their content and effects. In AML patients, especially in cases developed from MDS, SPAC might be useful because it can be given orally even in an outpatient.

Overexpression of mitochondrial genes in alloplasmic common wheat with a cytoplasm of wheatgrass (Agropyron trichophorum) showing depressed vigor and male sterility

An alloplasmic hybrid (nucleus-cytoplasm hybrid) of common wheat (Triticum aestivum) with a cytoplasm of wheatgrass (Agropyron trichophorum) shows highly depressed vigor and complete male sterility. The presence of one short-arm telocentric homeologous group 1 chromosome (telosome) of the cytoplasm donor, however, restores normal vigor and male fertility of the hybrid. To study role(s) of the telosome on vigor/fertility restoration, mitochondrial genome organization and gene expression were compared among seedlings of the alloplasmic line showing depressed vigor, the corresponding restored line having a pair of the telosomes, and a euplasmic nuclear donor as control. No differences were detected in the mitochondrial genome structure between the depressed line and the restored line. Northern blot analysis using ten mitochondrial genes as probes showed no differences in transcript size and number between the depressed and restored lines, although clear differences were found in size of the major transcripts of two genes (cob and orf25) between the alloplasmic lines and the euplasmic control. Steady-state transcript levels were higher in the depressed line than in the other lines for all the mitochondrial genes analyzed including rrn18&5 when the same amount of mitochondrial RNA was loaded. The amount of rrn18&5 transcript in the total cellular RNA, however, did not differ among the lines. Run-on transcription analysis demonstrated markedly elevated transcriptional activities of all the mitochondrial genes analyzed in the depressed line based on unit amount of mitochondrial DNA, RNA and protein. The presence of Agropyron telosomes apparently normalized the level of mitochondrial transcription. These observations suggest either direct or indirect association of the observed mitochondrial gene overexpression with the depressed vigor and male sterility of the alloplasmic hybrid.

Primary gastric Hodgkin's disease. Morphologic, immunohistochemical, and immunogenetic analyses

Two cases of primary gastric Hodgkin's disease were examined morphologically and immunohistochemically. Immunogenetic studies were also made in one of the cases. Case 1 was diagnosed as nodular sclerosis and case 2 as mixed cellularity Hodgkin's disease. Large atypical mononuclear or multinucleated giant cells were immunohistochemically positive for BerH2, whereas they were negative for LCA, L26, DAKO CD3, MT1, UCHL-1, S100 protein, and MAC387. In case 1, large atypical cells examined immunohistochemically on frozen tissue specimens were positive for Ki-1 and negative for T- and B-cell markers. Southern blot hybridization studies performed on material from case 1 revealed germline configuration of immunoglobulin JH and T-cell-receptor beta-chain genes. To our knowledge, this is the first report in which primary gastric Hodgkin's disease has been studied immunogenetically. Although rare in incidence, the existence of Hodgkin's disease in the stomach must be noted.

The action of substance P methyl ester on cochlear potentials in the guinea pig

The action of the substance P agonist, substance P methyl ester (SPME) on cochlear potentials was examined in the guinea pig. Previous studies have shown that SPME is a selective agonist for neurokinin 1 (NK1) receptor. Perfusion with SPME at a concentration of more than 10(-6)M produced an increase in the amplitudes of the compound action potential and negative summating potential in a dose-dependent manner. N1 latency showed a tendency to be shortened, but this change was not significant. Amplitudes of the cochlear microphonics and endocochlear potential remained unchanged. Substance P fragment 7-11, an inactive analogue, produced no changes in the cochlear potentials. In contrast, the substance P antagonist [D-Pro2, D-Trp7,9]-SP blocked the action of SPME on the cochlear potentials. These results suggest that substance P may modulate neurotransmission through NK1 receptors in the cochlea.

Studies on the quantitative autoradiography. II. Radioluminography for quantitative autoradiography of 3H

The process of obtaining 3H-autoradiographic (ARG) images has been expected for a long time. A few X-ray films with no protection layer are commercially available, however, they do not give a reliable image which can be quantitated and can give good contrast. We tried to fabricate a 3H-type sensor which has no protection layer on a highly sensitive sensor, and called it Imaging plate (IP). The IP is composed of one of the specially designed photo-stimulable phosphors containing of BaFX: Eu2+(X = Cl, Br or I) crystals. Results indicated a good contrast and reliable whole-body ARG image of 3H-labelled glucose with trial IP, which has never been obtained with any X-ray films even if these were subjected to a long exposure time. The ARG image can be displayed by either black-and-white hard copy or a colored one with the digital display representing relative intensity of photostimulated luminescence (PSL) without back ground (BG) or relative intensity concentration ((PSL-BG)/S), where S was equivalent to 100 pixels (1 mm2). Similarly to the experimental results of 14C, the linear relationship relative intensity and radioactivity of the 3H standard sources was demonstrated with a very wide range of 10(2) to 10(5) dpm/mg upon the exposure for 7d. Also the relationship between relative intensity and relative exposure (radioactivity x exposure time) was linear within the latitude of relative intensity 10(1) to 10(5) (PSL-BG). The trial IP was particularly effective for the quantitative autoradiography of TLC plates.(ABSTRACT TRUNCATED AT 250 WORDS)

Radiation-induced lymphomas in MSM, (BALB/cHeA x MSM) F1 and (BALB/cHeA x STS/A) F1 hybrid mice

M.MOL-MSM (MSM) mice derived from Mus musculus molossinus progenitors showed extreme resistance to the induction of lymphomas following whole-body X-irradiation with four doses of 1.7 Gy. (BALB/cHeA x MSM) F1 mice between a high lymphoma strain, BALB/cHeA and the MSM showed a high incidence of radiation-induced lymphomas which was quite similar to that in BALB/cHeA mice, but the latent period was prolonged in the hybrids. Susceptibility in incidence was dominant over resistance in these crosses. Incidences of (BALB/cHeA x MSM)F1 hybrids irradiated with four doses of 2.5 Gy X-rays were 77% in females and 88% in males. F1 hybrids between BALB/cHeA and another resistant strain STS/A, (BALB/cHeA x STS/A) F1, also showed a high level of susceptibility, that is, lymphoma incidence was 64% in females and 63% in males. The mean latent period in the (BALB/cHeA x STS/A) F1 hybrids was similar to that in (BALB/cHeA x MSM) F1 hybrids. As all cases of tumors developed in F1 hybrids are informative concerning the detection of the loss of heterozygosity in the loci depending on the combination of two parental strains, the radiation-induced lymphomas obtained from (BALB/cHeA x MSM) F1 and (BALB/cHeA x STS/A) F1 hybrids could be useful for fine analysis of the genetic alterations involved in lymphomagenesis.

Wheat phylogeny determined by RFLP analysis of nuclear DNA. 2. Wild tetraploid wheats

Intra- and inter-specific variations in the nuclear DNA of Triticum dicoccoides Körn. (2n = 28, genome constitution AABB) and T. araraticum Jakubz. (2n = 28, AAGG), wild species, respectively, of the Emmer and Timopheevi group, were studied by restriction fragment length polymorphism (RFLP) analysis. Total DNAs of 32 T. dicoccoides and 24 T. araraticum accessions, collected from throughout the distribution areas of these species, were treated with two 6-bp cutters and hybridized with 30 nuclear DNA clones as probes to detect RFLPs. A total of 167 hybrid bands were observed per accession. All the enzyme-probe combinations showed RFLPs between accessions. The average genetic distance between the T. dicoccoides accessions was 0.0135 ± 0.0031 and that between the T. araraticum accessions 0.0036 ± 0.0015, indicative of about a four-fold intraspecific variation in T. dicoccoides as compared to T. araraticum in terms of genetic distance. No significant genetic differentiation was found for the geographical populations of these species, the genetic distance between the two species being 0.0482 ± 0.0022. The interspecific divergence corrected for intraspecific divergence was 0.0395, about three times that for T. dicoccoides and 11 times that for T. araraticum. The results show that in the wild state the Emmer and Timopheevi groups are clearly differentiated and that T. dicoccoides has much greater variation than T. araraticum, suggesting a relatively recent origin for the latter and therefore a diphyletic origin for these species.

Changes in calcium distribution in the utricular supporting cells of the guinea pig

Changes in calcium distribution in cultured utricular supporting cells following streptomycin sulfate (SM) intoxication were investigated by means of an organ culture system using potassium pyroantimonate (PA) precipitation. PA precipitation showed that calcium ions are located in the otoconia and in the secretory granules of the supporting cells. Exposure of the supporting cells to SM increased the number of lysosomes and reduced the secretory granules in the cytoplasm. These lysosomes had many granules containing calcium ion. It is suggested that calcium secretion from the secretory granules was inhibited by SM and that this might lead to reduction of otoconia.

Complete Nucleotide Sequence of Mouse Mammary Tumor Virus from JYG Chinese Wild Mice: Absence of Bacterial Insertion Sequences in the Cloned Viral gag Gene

Mammary tumors of a newly isolated strain of Chinese wild mouse (JYG mouse) harbor exogenous mouse mammary tumor virus (MMTV). The complete nucleotide sequence of exogenous JYG-MMTV was determined on the proviral 5' long terminal repeat (LTR)(partial)-gag-pol-env-3' LTR (partial) fragment cloned into a plasmid vector and the cDNA sequence from JYG-MMTV producing cells. Similarly to the other MMTV species the LTR of JYG-MMTV contains an open reading frame (ORF). The amino acid sequence of the JYG-MMTV ORF resembles that of SW-MMTV (92% identity) and endogenous Mtv-7 (93% identity) especially at the C-terminal region. Thus, a functional similarity in T-cell receptor V beta recognition as a superantigen is implicated among these MMTV species. Analysis of the viral gag nucleotide sequence revealed that this gene is not disrupted by the bacterial insertion sequence IS1 or IS2, which have been reported to be present in the majority of the plasmids containing the gag region. Comparison of amino acid sequences of JYG-MMTV with those of BR6-MMTV showed that over 96% of the amino acids of gag, pol, protease and env products are identical. These results suggest the intact nature of the nucleotide sequence of the near full-length MMTV genome cloned in the plasmid.

Cloning of the rat Gadd45 cDNA and its mRNA expression in the brain

We cloned the rat Gadd45 (growth arrest and DNA damage inducible) cDNA and examined its mRNA induction by gamma-ray irradiation in the rat brain. The rat Gadd45 cDNA sequence was highly homologous to the previously published human and hamster cDNAs, and was partially similar to the 28S rRNA gene. The mRNA encoding rat GADD45 was induced in the brain after gamma-ray irradiation. This finding indicates that Gadd45 is an inducible gene following the ionizing radiation, not only in cultured cells in vitro, but also in animal tissues in vivo.

Ultracytochemistry of thymic epithelial cells in rats given organotin

A combined light-and electron microscopic study of thymic changes in the adult rats after di-n-butyltin dichloride (DBTC) administration has been made. A rapid depletion of thymocytes in the cortex of thymus and subsequent rapid recovery of the number of thymocytes occurred. In this process, at 1-3 days after DBTC treatment the number of necrotic thymocytes was maximal. At 3-6 days, reticular epithelial cells were predominantly phagocytizing and acid phosphatase-positive in the cortex and cortico-medullary regions, where they appeared to develop from macrophage-like cells. During acute involution, it was likely that reticular epithelial cells were phagocytic and remove the necrotic thymocytes. The proportion of CD4+ CD8+ cells in the cortex of thymus was maximally reduced from day 3 onwards and reached the lowest level at 6 days after single oral dose of DBTC. On these days, the proportions of CD4- CD8- and single positive cell (CD4- CD8+ or CD4+ CD8-) subsets were relatively increased. These data suggest that DBTC preferentially causes an initial depletion of CD4+ CD8+ cells in thymus, and both macrophages and reticular epithelial cells of the cortex may be involved in the rapid removal of damaged thymocytes from thymus.

Morphological changes in rat aortic endothelial cell line stimulated by endothelin

We have reported that endothelin (ET)-1 activates interleukin (IL)-6 production in rat aortic endothelial cell line (WAE-1 cell). In this experiment, we investigated the morphological changes induced by ET-1 in cultured WAE-1 cells. The cells were treated with ET-1 for 8 h or 24 h, and then compared with untreated cells by light and electron microscopies. The WAE-1 cells treated with ET-1 for 8 h showed remarkable alterations as following: by light microscopic observation, the cells were enlarged and filled with many vesicles in the cytoplasm, and by electron microscopic observation, the cells showed the increases of nuclear membrane infoldings, increased density of chromatin granules just inside the nuclear membrane, and multivesicular bodies in the cytoplasm. These morphological changes were hardly observed in WAE-1 cells-treated with ET-1 for 24 h. It was suggested that ET-1 stimulated DNA synthesis and secretion of cytoplasmic products in WAE-1 cells.

Natural killer cell leukemia. An autopsy case

We describe an autopsy case of natural killer cell leukemia. Leukemic cells appeared morphologically as large granular lymphocytes and expressed a restricted natural killer cell phenotype (CD2, CD38, CD56, HLA-DR). Immunogenotypic analysis revealed germline configurations of TCR-beta, TCR-gamma, and JH genes, indicating a non-T-cell or non-B-cell lineage. These features are consistent with natural killer cell leukemia, a recently proposed clinicopathologic entity. Autopsy findings were characterized by an extremely dense infiltration of leukemic cells in most organs, along with destruction of the normal architecture, corresponding to an aggressive clinical course. Hemophagocytic histiocytosis and an absence of chronic inflammatory reactions caused by recurrent infection in our case are different from morphologic features of CD3+ large granular lymphocytic leukemia. No relationship between Epstein-Barr virus and natural killer cell leukemia was observed.