Rat amygdaloid neuron responses during auditory discrimination

To investigate amygdaloid contribution to stimulus-affect association and to emotional behavior, single neuron activity was recorded in the basolateral and corticomedial amygdala of the rat amygdala during discrimination of conditioned cue tones associated with positive (glucose and intracranial self-stimulation) and negative (weak electric footshock) unconditioned stimuli. Amygdaloid neurons that responded to two rewarding unconditioned stimuli responded in the same manner to both. Responses to conditioned cue tones and those to rewards were also significantly related, suggesting that amygdaloid neuronal responses to conditioned stimuli are closely related to the affective nature of the corresponding unconditioned stimulation. These might be neuronal functions that underlie stimulus-affect association in the amygdala. In random repeated trials, including acquisition to conditioned cue tones and extinction after acquisition, response plasticity was more evident in basolateral than in corticomedial neurons. Furthermore, more basolateral than corticomedial neurons differentiated glucose and its cue from intracranial self-stimulation and its cue by responding to one but not the other. More basolateral than corticomedial neurons were excited by intracranial self-stimulation and its cue and inhibited by footshock and its cue. The differences between the two nuclear groups suggest that basolateral neurons are more plastic and discriminative, and corticomedial neurons respond indiscriminately to positive and negative unconditioned or conditioned stimuli. The results indicate amygdaloid neuron involvement in stimulus-affect association. Basolateral neurons may be more involved than corticomedial neurons in discriminating and learning conditioned stimuli.

Subtype selectivity of a novel endothelin antagonist, FR139317, for the two endothelin receptors in transfected Chinese hamster ovary cells

We investigated the receptor-binding properties and the antagonist activities of FR139317, a novel endothelin (ET) antagonist, in transfected Chinese hamster ovary cells permanently expressing the two ET receptor subtypes (ETA and ETB). In displacement analysis using membrane preparations derived from the receptor-expressing cells, FR139317 showed a high affinity for ETA (Ki = 1 nM) and a lower affinity for ETB (Ki = 7.3 microM). FR139317 inhibited ETA-mediated phosphatidylinositol hydrolysis and arachidonic acid release and produced a parallel shift in the dose-response curve for ET-1, with respective pA2 values of 8.2 and 7.7. In contrast, FR139317 had no inhibitory effects on these ET-1-induced responses in ETB-expressing cells. FR139317 itself showed no stimulatory effects on phosphatidylinositol hydrolysis and arachidonic acid release in ETA- and ETB-expressing cells. Thus, FR139317 is a potent, competitive, and highly selective antagonist for ETA. This compound should be a powerful tool for investigation of the physiological properties of ETA and exploration of its role in diseases.

[Cyclosporine therapy of adult onset Still's disease with disseminated intravascular coagulation]

In April, 1991, a 61-year-old man was admitted to our hospital because of pancytopenia and disseminated intravascular coagulation (DIC). Five years prior to admission he had developed high fever, skin eruption and arthralgia which had been improved by antibiotics, but recurred. Steroid therapy was ineffective for pancytopenia and DIC. Laboratory findings were as follows: RBC count, 274 x 10(4)/microliters; WBC count, 470/microliters; Platelets, 6.4 x 10(4)/microliters; fibrinogen, 153mg/dl; FDP, 67.0 micrograms/ml; FDP-D.Dimer, 13040ng/ml; thrombin-antithrombin complex, > 60.0ng/ml; and plasmin alpha 2-plasmin inhibitor complex, 10.3 micrograms/ml. As we suspected adult onset Still's disease on the basis of clinical course, we treated him with methylprednisolone pulse therapy, which was, however, ineffective. leukocytopenia, thrombocytopenia and DIC improved after cyclosporine treatment. Since cyclosporine is known to be very effective to autoimmune diseases, we speculate that in this patient immunological mechanism may be involve in the pathogenesis of DIC.

[Ogilvie's syndrome in pregnancy--a case report]

A 23-year-old female in the 28th week of pregnancy was admitted with an acute abdominal distension. The plain X-ray films showed a marked gaseous dilatation of the colon from the cecum to the splenic flexure. A tube colostomy was performed. Her postoperative course was uneventful and she improved progressively. Her pregnancy and delivery elapsed uneventfully there after. After the delivery she again complained of marked abdominal distension. The colonoscopic decompression in combination with the administration of Cisapride was successfully accomplished. Ogilvie's syndrome is characterized by an unobstructed colon which progresses to marked dilatation. When the colonic diameter becomes 12cm or more, surgical decompression should be recommended to avoid the hazard of spontaneous rupture. This is the first reported case of Ogilvie's syndrome in pregnancy in Japan.

Cloning of a cDNA encoding rat intestinal 15 kDa protein and its tissue distribution

A cDNA encoding rat intestinal 15 kDa protein was isolated and sequenced from a rat ileum-specific cDNA library. This cDNA was found to contain an open reading frame of 384 nucleotides as well as 5' (27 nucleotides) and 3' (46 nucleotides) non-coding regions. The deduced sequence of 127 amino acids was identical to that of rat I-15P which was purified from rat intestinal epithelium. The nucleotide sequence of the open reading frame exhibited 79% identity to that of the porcine gastrotropin. Northern blot analysis indicated that the same size of transcript as that of the ileum was detected in the ovary, suggesting that I-15P or a homologous protein might be involved in the metabolism of steroids in steroid hormone-producing tissues.

Effect of an aromatase inhibitor in human follicular fluid on DNA synthesis of granulosa cells, theca cells, and follicles

An aromatase inhibitor was identified in human follicular fluid. We sought to examine the effects of this inhibitor on granulosa cells, theca cells, a mixture of granulosa and theca cells, and follicles. Granulosa cells, theca cells, the mixture of granulosa and theca cells, and follicles were incubated with [3H]-thymidine and aromatase inhibitor at 37 degrees C for 40 h in Ham F-10 medium. The radioactivities of acid-soluble fractions were counted. Aromatase inhibitor markedly inhibited the DNA synthesis of granulosa cells and follicles, but it did not inhibit the mixture of granulosa and theca cells. This suggested that aromatase inhibitor was a factor in the follicle paracrine system and acted mainly on granulosa cells.

The mouse Mel-18 "RING-finger" gene: genomic organization, promoter analysis and chromosomal assignment

The chromosome gene for mouse Mel-18 (mMel-18) protein has been isolated and characterized. The entire mMel-18 gene is composed of thirteen exons spanning about 15 kilobases, in which the protein is encoded by exons 5-13. The "RING-finger" motif of Mel-18 protein that displays a significant evolutionary resemblance to other RING-finger nuclear proteins is encoded by exons 5 and 6. Exon 13 encodes a C-terminal proline/serine-rich domain that is homologous to some transactivator proteins. Sequence analysis of the 5'-flanking region revealed the presence of potential binding sites for transcription factors such as SP-1, NF-1, NF-kappa B and c-myc/max. At least two major cap sites and three minor cap sites were identified by S1 mapping and primer extension analysis. We propose that the mMel-18 gene is regulated by two different types of promoters, the CAAT-TATA box promoter and the GC-rich TATA-less promoter. The 2.4 kb DNA fragment of the 5'-flanking region exhibited constitutive promoter activity when transfected into L cells. By the in situ hybridization method, the mMel-18 gene was assigned to mouse chromosome 10C3.

An endothelin ETA receptor antagonist, FR139317, ameliorates cerebral vasospasm in dogs

The role of endothelin in the pathogenesis of cerebral vasospasm after subarachinoid hemorrhage was investigated by evaluating the effect of FR139317, a novel potent ETA receptor antagonist, on the vasospasm in a canine two-hemorrhage model. Intracisternal administration of FR139317 (0.1 mg) significantly reduced the vasoconstriction of the basilar artery at day 7 (control group, n = 6, 61.6 +/- 4.0%, FR139317 treated group, n = 6, 75.9 +/- 1.5% of basal diameter, p < 0.01). In normal anesthetized dogs, the intracisternal administration of FR139317 did not affect the basal diameter of the basilar artery, blood pressure or heart rate. These results suggest that endothelin plays an important role in the pathogenesis of cerebral vasospasm after subarachnoid hemorrhage, and that FR139317 could be a valuable tool for preventing vasospasm after subarachnoid hemorrhage.

Regressing nevoid nail melanosis in childhood

The natural course of nail pigmentation was documented in 4 Japanese children. Although initial progression of melanosis concerning size and degree of pigmentation was noted, all cases showed a tendency to fade during the follow-up period. The published cases of nevoid nail melanosis in childhood were reviewed, and we concluded that they were essentially benign. However, should there be any suspicion of malignant changes, punch biopsy is indicated for medico-legal reasons. Management of growing pigmented nail streaks in childhood is one of the most difficult and delicate problems facing dermatologists, as they can be precursors of malignant melanoma. There is a condition of the nail known as longitudinal melanonychia or naevus striae unguis, possibly of nevoid nature. Prevalence rates of nevoid diseases showing pigmentation of the skin vary depending on the ethnic origin. In order to understand the natural course of nail area pigmentation in childhood, we have followed 4 Japanese children with such a condition. We report our observations and review the literature.

1,25-Dihydroxy vitamin D3 stimulation of TGF-beta expression in chick embryonic calvarial bone

Bone is a highly active producer of the cytokine, transforming growth factor-beta (TGF-beta), which is likely to be functionally involved in the regulation and maintenance of bone development and growth. In addition, bone functions are also regulated by the major calciotropic hormone, 1,25-dihydroxy vitamin D3 (1,25(OH)2D3). This investigation aims to examine the possible relationship between TGF-beta and 1,25(OH)2D3 using an unique calcium-deficient chick embryonic model. By means of long-term culture without the eggshell (shell-less or SL culture), chick embryos may be rendered severely calcium-deficient with gross undermineralization of the skeleton. We have previously observed that the calvaria of these SL embryos develop abnormal chondrogenic phenotype, with production of collagen type II, and elevated TGF-beta expression. Administration of 1,25(OH)2D3 to the SL embryos in vivo on incubation days 10 and 12 (SL + D embryos) resulted in near-normal serum calcium on day 14 and improved calvarial calcification. However, TGF-beta expression in the SL + D calvaria was further increased compared to untreated SL calvaria, when analyzed at both the mRNA and protein levels. Histolocalization of gene expression by immunohistochemistry and in situ hybridization revealed that cells in the less mineralized orbital and temporal zones of the calvarium are particularly affected by the 1,25(OH)2D3 treatment. Interestingly, the increased TGF-beta expression resulting from 1,25(OH)2D3 treatment did not correct the aberrant collagen phenotype in the SL calvaria. These observations suggest that TGF-beta expression by bone cells in situ is stimulated by 1,25(OH)2D3, and that normal cellular differentiation and morphogenesis of the embryonic calvaria are dependent on proper and balanced TGF-beta expression as well as the state of tissue mineralization.

Neuronal responses in monkey anterior putamen during operant bar-press behavior

Single neuron activity was recorded in the monkey anterior putamen to compare visuomotor-related responses during operant bar-press behavior with visual discrimination of objects. Of 615 neurons recorded, 9.8% (60/615) responded to the presentation of food during forced delay of access to the bar. Of these 60 neurons, 38 were also tested with nonfood, and 19 of these responded to the nonfood objects regardless of the following movement. The amplitude of the visual-related responses of some differential neurons was graded for different objects to reflect the relative degree of preference for the food presented. However, these responses disappeared in reaction time tasks in which the bar could be accessed for pressing immediately upon presentation of an object. The visual response latency of differential neurons ranged from 50 to 700 ms (mean +/- SD, 386 +/- 211 ms), which was longer than that of the nondifferential responses (207 +/- 204 ms). These results suggest that anterior putamen neurons might participate in estimation of visual information that could be related to forecasting movement.

Significance of endothelial deposition of von Willebrand factor in thrombotic thrombocytopenic purpura: autopsy findings of a case complicated with systemic lupus erythematosus

We report the renal immunohistochemical findings of a patient with thrombotic thrombocytopenic purpura complicated with systemic lupus erythematosus. Aggregated platelets were observed adhering to the arteriole walls. Intense deposition of von Willebrand factor (vWF) was noted in the endothelium, even in areas where thrombi were not seen. This difference in the distribution of platelets and vWF suggested that the endothelium was damaged prior to platelet aggregation.

Manganese K-edge X-ray absorption spectra of the cyclic S-states in the photosynthetic oxygen-evolving system

A set of Mn K-edge XANES spectra due to the redox states S0-S3 of the OEC were determined by constructing a highly-sensitive X-ray detection system for use with physiologically native PS II membranes capable of cycling under a series of saturating laser-flashes. The spectra showed almost parallel upshifts with relatively high K-edge half-height energies given by 6550.9±0.2 eV, 6551.7±0.2 eV, 6552.5±0.2 eV and 6553.6±0.2 eV for the S0, S1, S2 and S3 states, respectively. The successive difference spectra between S0 and S1, S1 and S2, and S2 and S3 states were found to exhibit a similar peak around 6552-6553 eV, indicating that one Mn(III) ion or its direct ligand is univalently oxidized upon each individual S-state transition from S0 to S3. The present data, together with other observations of EPR and pre-edge XANES spectroscopy, suggest that the oxidation state of the Mn cluster undergoes a periodic change; S0: Mn(III,III,III,IV) → S1: Mn(III,IV,III,IV) → S2: Mn(III,IV,IV,IV) → S3: Mn(IV,IV,IV,IV) or Mn(III,IV,IV,IV)·L(+) with L being a direct ligand of a Mn(III) ion.

Comparison of the age- and tumor-associated changes in the c-myc gene methylation in mouse liver

Study of DNA methylation of the c-myc gene in liver tumors of BCF1 mice treated with various agents revealed frequent alteration from that in normal liver. The alteration, however, was complex and showed either an increase or a decrease of methylation to various degrees. On the other hand, the tumors obtained from middle-aged C3H/He mice, which develop liver tumors spontaneously at a high incidence rate starting in middle age, showed predominantly increases of methylation in the c-myc gene, while the large tumors found in older mice revealed decreases. The normal part of the liver showed a slight gradual age-dependent increase. These suggest that hypermethylation of the c-myc gene is common to aging and early tumor development in liver. Thus the alteration of DNA methylation seems to be a good clue to investigate why the tumor incidence rate increases rapidly as individuals grow older.

Protein synthesis-dependent cytoplasmic translocation of p53 protein after serum stimulation of growth-arrested MCF-7 cells

p53 protein was localized in the cytoplasm of growing and in the nucleus of growth-arrested MCF-7 cells. While the absolute amount and rate of synthesis of p53 in growing and arrested cells were nearly the same, the protein in growing cells was phosphorylated to a greater extent than in arrested cells. The abilities of the cytoplasmic and nuclear p53 proteins to bind to DNA sequences specific for p53 protein binding did not differ remarkably despite their differential phosphorylation levels. Serum-induced translocation of the p53 protein from the nucleus to the cytoplasm, as well as DNA and protein synthesis, were inhibited by cycloheximide. These results suggest that the DNA synthesis-associated cytoplasmic translocation of p53 protein in response to serum stimulation depends on de novo protein synthesis and not on alteration of the protein's ability to bind to specific DNA sequences.

Biological significance of DNA methylation in the ageing process

In order to understand the possible importance of DNA methylation in ageing, characteristics of its age-associated changes were examined in mouse and man. The total methylated deoxycytidine level in the genome decreased in the senescent period in mouse liver, but not in mouse brain and human liver. The examination of DNA methylation in each individual gene revealed that only a few genes showed alteration in the senescent phase while many genes change in the maturation period. The alterations were gene- and tissue-specific. Comparison of short-living mouse and long-living man for the age-associated changes of the c-myc gene methylation revealed that the rate of change in mouse was about 20 times faster than that in man. This suggests a deep involvement of DNA methylation in ageing. Further investigations into the causes and consequences of the changes would clarify a basic mechanism of ageing.

Clonal analysis of human T-cell responses to fractionated house dust mite antigens (Dermatophagoides pteronyssinus)

In the present study, we investigated the cellular basis of house dust mite-driven immune responsiveness in an atopic individual with perennial rhinitis. We established 40 human T-cell clones (CD3+, 4+, 8-) reactive to Dermatophagoides pteronyssinus (Dp) antigen under the restriction of HLA-DR. By using the crude Dp antigen and its 14 molecular weight (MW) fractions, we analyzed the distribution of T-cell-recognizing sites in the whole Dp extract. We tested T-cell-mediated immunity through two parameters; the identification of Dp fractions inducing T-cell proliferation, and the ability of T-cell clones to secrete IL-2, IL-4, and IFN-gamma. According to a prominent peak among fraction-driven T-cell proliferation, we observed that T-cell clones that recognized 45,000- to 95,000-MW fractions were common, while clones reactive to 15,000- to 25,000-MW fractions were less frequent. Several clones were also reactive to antigens of Dermatophagoides farinae or other insects. Based on the responses of cloned T cells, we observed at least 9 distinct T epitopes in crude Dp antigen. These T-cell clones had a heterogenous secretory pattern of cytokines. T-cell clones showed no association between their ability to produce regulatory cytokine and their recognition of particular Dp fractions.

Changes of DNA methylation in protooncogenes in the process of radiation-induced transformation of mouse m5S/1M cells in vitro

To assess the importance of changes in DNA methylation in an X-ray-induced cellular transformation process, methylation patterns of five nuclear protooncogenes in fifteen transformant clones were studied and compared to that of the parental non-transformed cell line m5S/1M. All transformants examined revealed an alteration in DNA methylation in some of the genes, although these changes were variable among them. A comparison of cellular characteristics with corresponding DNA methylation changes in different clones suggested that the loss of contact inhibition and the gain of anchorage independency were associated with increases of methylation in many genes, whereas the acquisition of tumorigenicity was often accompanied by a decrease of methylation in the N-myc and c-myc genes. Resultant data indicate that the alteration of DNA methylation is closely related to transformation process, yet how this involvement occurs is complex and remains unclear.

[Utility of recombinant human erythropoietin on the anemia of elderly hemodialysis patients]

Recombinant human erythropoietin was administered to 59 patients over 65 years of age receiving maintenance hemodialysis treatment in Kyoto and Shiga district, in order to evaluate its utility on renal anemia. After 6 months of administration, the hematocrit rose from 20.8 +/- 3.5% to 28.0 +/- 3.7% with concomitant improvement of subjective symptoms related to anemia. Twelve patients developed side effects, in 10 of whom elevation of blood pressure was observed. We found no clinically significant abnormalities in the laboratory data. In conclusion, recombinant human erythropoietin is highly useful in the treatment of renal anemia in elderly hemodialysis patients.