Phosphorylated sites of M(r) 25,000 protein, a putative protein phosphatase 2A modulator, and phosphorylation of the synthetic peptide containing these sites by protein kinase C

The M(r) 25,000 protein isolated from Xenopus laevis oocytes was shown to be an effective phosphate acceptor for Ca(2+)-phospholipid-dependent protein kinase (protein kinase C) [Hashimoto, E. et al. (1995) J. Biochem. 118, 453-460]. In this study, the sites of this protein phosphorylated by protein kinase C were determined and the mechanism of substrate recognition was studied using a synthetic peptide containing the phosphorylation sites. After incorporation of about 2 mol of phosphate per mol of this protein, the radioactive protein was digested with trypsin and the phosphopeptides were purified by a series of column chromatographies. The amino acid sequence of the major radioactive peptide was shown to be Ser-Arg-Val-Ser-Lys-Arg. This and previous results suggest that the two serine residues at the amino-terminal region were phosphorylated by protein kinase C. To confirm this, the phosphorylated protein was directly analyzed for the amino acid sequence. The percent distribution of dithiothreitol adduct of the phenylthiohydantoin derivative of serine (PTH-serine) compared with that of PTH-serine increased at the first and fourth cycles of the sequence analysis. When the synthetic peptide composed of the amino-terminal eleven amino acids was employed as phosphate acceptor, the Km value was unexpectedly high (1.1 mM) compared with that of the native protein (0.5 muM). A stimulatory effect of M(r) 25,000 protein on the activity of protein phosphatase 2A was further enhanced after phosphorylation by protein kinase C. These results suggest that the two serine residues recognized by protein kinase C may have some role in the regulation of this M(r) 25,000 protein.

Treatment of T3 and T4 carcinomas of the gallbladder

Forty-nine patients with T3 and T4 carcinoma of the gallbladder were treated by three different regimens. Group 1 consisted of 26 patients treated with combined resection alone; group 2 was twelve patients whose tumors had spread to the hepatoduodenal ligament treated with combined resection plus intraoperative radiation therapy; group 3 comprised eleven patients with nonresectable tumors treated with hyperthermia in combination with chemoradiation therapy (HCRT). The difference in the survival rates between group 1 and 2 were statistically significant (p < 0.001); however, the difference between group 2 and 3 was not significant. In group 1, there was a significant difference between patients with and without lymph node involvement in the 3-year survival rate (p < 0.01). Thus, the only patients without involvement of regional lymph nodes and the hepatoduodenal ligament have the best potential for long-term survival through aggressive surgical approaches. HCRT may provide an alternative palliation for patients with advanced carcinoma showing obstructive jaundice.

Modulation of cholinergic synaptic functions by sialylcholesterol

The effects of sialylcholesterol, a synthetic ganglioside analogue, on cholinergic synaptic functions were investigated using synaptosomes prepared from C57BL/6 mouse brain cortices. Addition of alpha-sialylcholesterol stimulated high K (50 mM)-evoked acetylcholine (ACh) release from synaptosomes at concentrations ranging from 1 to 5 microM. The beta-anomer of the sialyl compound also increased the neurotransmitter release at 5 microM, but the effect was much smaller than that of the alpha-anomer. Beta-sialylcholesterol appeared to increase high-affinity choline uptake and Ach synthesis, resulting in an increment in the release of ACh. On the other hand, alpha-sialylcholesterol did not change the synthetic rate of ACh, and instead it increased the depolarization=induced influx of calcium ions into synaptosomes, while the beta-anomer did not affect the divalent cation influx. The enhanced calcium influx is thought to increase ACh release from synaptosomes treated with alpha-sialylcholesterol. These results imply that the two anomers of sialylcholesterol may modulate the synaptic membrane machinery differently, that is, the alpha-anomer may activate voltage-dependent calcium channels and the beta-anomer may facilitate high-affinity choline uptake. In order to evaluate the ameliorating effect of sialylcholesterol, alpha-sialylcholesterol was applied to the synaptosomes from aged mice (34 months old), which have been shown to have a decreased ACh release (Tanaka et al., 1995, J Neurosci Res, in press [1]). The reduced neurotransmitter release recovered to the levels of younger animals, suggesting that sialylcholesterol might have a potential therapeutic use for restoring synaptic function that occurs in aged brains.

[Clinical significance of genetic instability in gastrointestinal cancers]

We reviewed the clinical significance of genetic instability or replication error (RER) in human gastrointestinal carcinomas. The RER positive tumors are seen in about 10-30% of these carcinomas. The RER positive esophageal carcinomas tend to show unusual histologic subtypes such as adenocarcinoma or small cell carcinoma. The RER positive gastric carcinomas show no specific characteristics in our study while several investigators describe the high frequency of poorly differentiated adenocarcinomas of the higher frequency of advanced carcinomas. The RER positive colorectal carcinomas show a tendency to show poorly differentiation to occur in the proximal colon, to have no lymph node metastasis and to show good prognosis. Several candidate genes that may correlate with RER are shown.

Prenatal diagnosis of organic acidemias based on amniotic fluid levels of acylcarnitines

Acylcarnitines in amniotic fluid samples were analyzed for the prenatal diagnosis of propionic acidemia, methylmalonic aciduria, isovaleric acidemia, and glutaric aciduria by electrospray tandem mass spectrometry. Although the levels of the specific acylcarnitine between affected and unaffected cases showed an overlap, the ratios of propionylcarnitine to 4-carbon acylcarnitine levels for propionic acidemia and methylmalonic aciduria, those of isovalerylcarnitine to propionylcarnitine for isovaleric acidemia, and those of glutarylcarnitine to propionylcarnitine for glutaric aciduria type I were shown to be reliable indicators in the prenatal diagnosis. In addition, it is suggested that the combination of the ratios of glutarylcarnitine, isovaleryl-carnitine, and hexanoylcarnitine to propionylcarnitine may be useful for the prenatal diagnosis of glutaric aciduria type II.

Detection of antibodies against porcine reproductive and respiratory syndrome (PRRS) virus in swine sera by enzyme-linked immunosorbent assay

We developed an enzyme-linked immunosorbent assay (ELISA) to detect antibodies against PRRS virus in swine sera. The ELISA antigen was prepared from MARC-145 cells infected with PRRS virus. The results from serial serum samples from experimentally infected and random swine indicated that the ELISA was more sensitive than indirect fluorescent and immunoperoxidase monolayer assays. Since the ELISA enables many sera to be simultaneously and rapidly tested, it was useful for detection antibodies against PRRS virus in swine sera.

A pivotal role of IL-12 in Th1-dependent mouse liver injury

Intravenous injection of Propionibacterium acnes and lipopolysaccharide (LPS) with a 7 day interval caused CD4+ T cell-dependent severe liver injury in the C57BL/6 (H-2b) mouse strain. In contrast, BALB/c (H-2d) mice were resistant to P. acnes and LPS-induced liver injury. The different susceptibilities of the two mouse strains to liver injury appeared to be closely correlated with their different abilities to produce IFN-gamma after P. acnes priming. Namely, the sensitive C57BL/6 mouse strain produced a significant level of IFN-gamma 7-10 days after P. acnes injection, whereas no significant amount of serum IFN-gamma was detected in the resistant BALB/c mouse strain. The important role of IFN-gamma in liver injury was demonstrated from the finding that in vivo administration of anti-IFN-gamma mAb abrogated P. acnes and LPS-induced liver injury in C57BL/6 mice. Moreover, it was demonstrated that in vivo administration of recombinant IL-12, a key cytokine for the induction of IFN-gamma, into mice induced P. acnes and LPS-induced liver injury in the resistant BALB/c mouse strain. Conversely, in vivo administration of anti-IL-12 mAb blocked the development of liver injury in the sensitive C57BL/6 mouse strain. Moreover, it was demonstrated that the failure of the induction of liver injury in BALB/c mice appeared to be derived from the lack of expression of IL-12 at the local site of liver in P. acnes-primed mice. These results strongly indicated that endogenous IL-12, which stimulates Th1-dominant cellular immunity and IFN-gamma production, may be an essential cytokine on the course of T cell-dependent liver injury.

Expression of intercellular adhesion molecules 1 (ICAM-1) via an osmotic effect in human umbilical vein endothelial cells exposed to high glucose medium

To clarify the etiology of accelerated atherosclerosis in patients with diabetes mellitus, we measured expression of intercellular adhesion molecule 1 (ICAM-1), vascular cellular adhesion molecule 1 (VCAM-1), and E-selection on the cell surface by enzyme-linked immunosorbent assay and ICAM-1 mRNA content in human umbilical vein endothelial cells exposed to 5.5 mM glucose (NG), 33 mM glucose (HG), or 27.5 mM mannitol plus 5.5 mM glucose (HM).1) Cell-surface ICAM-1 expression in HG and HM cells was maximally increased by 37% and 32% (P < 0.01), respectively. This effect was dependent on glucose concentration in the medium and was found as early as 24 h and maintained until 6 days after exposing cells of HG. However, neither VCAM-1 nor E-selection expression were affected by HG conditions. 2) Both HG and HM induced increased mRNA content between 6 and 12 h after the stimulation. 3) Adhesion of THP-1 cells to endothelial cells exposed to HG and HM was increased, when compared to NG conditions. These results indicate that osmotic effects can induce increased mRNA and cell-surface expression of ICAM-1 via an as yet unknown mechanism.

The Genetic Variance Maintained by Pleiotropic Mutation

The equilibrium genetic variance of a quantitative trait under mutation-selection balance is analysed using a population genetic model. I assume that mutations have both phenotypic effects on a quantitative trait and deleterious effects on fitness itself. Hence, genetic variance is generated by pleiotropic effects of such deleterious mutations. If the deleterious effect is large, the predicted genetic variance is notably smaller than the equilibrium genetic variance predicted by the mutation-selection balance model with the rare-alleles approximation. The model further suggests that the ratio of the equilibrium genetic variance to the variance of allelic effects of new mutations is proportional to the ratio of total mutation load to the net selection coefficient on new mutations. It is also suggested that the net selection coefficient is equal to the per-generation proportional increment of genetic variance by new mutations.

[In vitro activities of sulopenem, a new parenteral penem, against anaerobes]

In vitro activities of sulopenem, a novel parenteral penem, was compared with those of imipenem, flomoxef, cefuzonam, cefoperazone and sulbactam/ampicillin against 66 reference strains (19 genera, 61 species) and 392 recent clinical isolates of anaerobic bacteria and fastidious aerobic bacteria. Sulopenem had a very broad spectrum against anaerobic bacteria. In general, this compound was active against anaerobic reference strains with MICs of < or = 0.78 micrograms/ml, while being the least active against Bifidobacterium spp. and less active than imipenem against Lactobacillus spp. Sulopenem was more active against Bacteroides fragilis isolates than imipenem and had the highest activities against Bacteroides thetaiotaomicron, Prevotella intermedia, Porphyromonas gingivalis, Fusobacterium spp. and Peptostreptococcus spp. among the antibiotics tested. Sulopenem was not hydrolyzed by oxyiminocephalosporinase type 1 produced by B. fragilis GAI-0558, GAI-7955 and GAI-10150 and its stability was comparable to imipenem. Its susceptibilities to hydrolysis by a metallo-beta-lactamase from B. fragilis GAI-30144 was less than imipenem. Sulopenem (120 mg/kg, 3 times a day for 4 days) was as effective as imipenem/cilastatin against a mixed intraabdominal mice infection due to E. coli and B. fragilis. Sulopenem (20 mg/kg twice a day for 5 days) did not induce an overgrowth of Clostridium difficile in the caecum of mice.

[Preserved implicit reading and the recovery of explicit reading in a pure alexic]

We described a 55-year-old, right-handed, university-educated Japanese man who showed pure alexia after an infarction in the territory of the left posterior cerebral artery. Damage to the corpus callosum was limited to the most caudal part of the splenium. In the early days of his illness, he demonstrated the inability to read aloud on either Kana (Japanese syllabograms) or Kanji (Japanese morphograms). In contrast, he could semantically categorize Kanji-words such as animals or non-animals. Subsequently, he gradually regained the ability of reading aloud Kanji as well as Kana. At that time, we further investigated the relation between his reading ability and the attributes of 881 Kanji characters including hieroglyphicity, concreteness, and familiarity. We found that he could more readily read Kanjis with higher hieroglyphicity, concreteness, and familiarity. The reading times for Kanji-words were significantly shorter than those of corresponding Kana-words. Moreover, he showed some difficulty to read Kana-words and Kana combinations without meaning when asked to perform repetitive opposing movements with his thumb and little finger inhibiting kinesthetic reading. The effect was not observed when he read Kanji-words. These results lead us to suggest the following: (1) the two components of reading, reading aloud and comprehension abilities, are dissociable in a pure alexic, especially in Kanji reading; and (2) recovery mechanisms underlying Kanji and Kana reading were different in our case. Namely, restitution of the direct connection through the residual splenium fibers between the visual word form processing area in the right hemisphere and the left angular gyrus was attributed to Kanji reading, and utilization of kinesthetic reading played an important role in Kana reading.

Synthetic collagen-like domain derived from the macrophage scavenger receptor binds acetylated low-density lipoprotein in vitro

The bovine macrophage scavenger receptor is a 70 kDa membrane protein that is trimerized on the macrophage cell surface. The receptor binds modified low-density lipoproteins (LDL). The core binding site is located within 22 residues at the C-terminus of the collagen-like domain of the receptor. The Lys residue at position 337 plays an important role in ligand binding. Here, the collagen-like domain was constructed using a peptide architecture technique, in which three collagenous peptide chains were crosslinked at their N-termini. The crosslinked peptide showed a collagen-like structure by circular dichroism and existed mainly in a monomeric triple helical form as shown by gel exclusion chromatography. The triple-stranded peptide was demonstrated to bind acetylated LDL (Ac-LDL) using regions derived from Gly323 to Lys340 of the natural bovine scavenger receptor. However, a single-stranded peptide with the same amino acid sequence did not bind Ac-LDL. Furthermore, a triple-stranded mutated peptide in which Lys corresponding to Lys337 in the mother protein was substituted with Ala showed no binding activity to Ac-LDL. These results, taken together, indicate that the synthetic collagen-like peptide has a similar structure to the binding site in the scavenger receptor, and support the view that the collagen-like domain of the natural scavenger receptor recognizes Ac-LDL.

Induction of OX40, a receptor of gp34, on T cells by trans-acting transcriptional activator, Tax, of human T-cell leukemia virus type I

gp34, which we had identified as a target molecule of the trans-activation by Tax of human T-cell leukemia virus type I (HTLV-I), has been found to bind OX40, a member of the tumor necrosis factor receptor family, resulting in growth stimulation of activated T cells. We here demonstrate that not only gp34 (OX40L), but also OX40 can be transcriptionally activated by Tax. Three Tax-producing human T-cell lines carrying the HTLV-I genome expressed OX40 on their surfaces. Furthermore, Tax-induced transcriptional activation of OX40 was shown in Tax-inducible JPX-9 cells. These results demonstrate that both OX40 and its ligand (gp34) are constitutively expressed on the surfaces of Tax-expressing T lymphocytes, suggesting that the OX40L/OX40 system contributes to growth stimulation of the virus-infected T cells.

CBP as a transcriptional coactivator of c-Myb

CBP (CREB-binding protein) is a transcriptional coactivator of CREB (cAMP response element-binding) protein, which is directly phosphorylated by PKA (cAMP-dependent protein kinase A). CBP interacts with the activated phosphorylated form of CREB but not with the nonphosphorylated form. We report here that CBP is also a coactivator of the c-myb proto-oncogene product (c-Myb), which is a sequence-specific transcriptional activator. CBP directly binds to the region containing the transcriptional activation domain of c-Myb in a phosphorylation-independent manner in vitro. The domain of CBP that touches c-Myb is also required for binding to CREB. A c-Myb/CBP complex in vivo was demonstrated by a yeast two-hybrid assay. CBP stimulates the c-Myb-dependent transcriptional activation. Conversely, the expression of antisense RNA of CBP represses c-Myb-induced transcriptional activation. In addition, adenovirus EIA, which binds to CBP, inhibits c-Myb-induced transcriptional activation. Our data thus identify CBP as a coactivator of c-Myb. These results suggest that CBP functions as a coactivator for more transcriptional activators than were thought previously.

[Dip-shaped hearing loss of Békésy audiogram in high school students]

Small dip-shaped hearing loss may be frequently observed on Bekesy audiograms in ears without any hearing loss on pure tone audiograms. Hearing tests and otoacoustic emission measurements were performed in club member of 2 senior high schools (K-D School and S-D School), in order to determine any relationship between inner ear impairments and the small dips on Bekesy audiograms. In the kendo, soccer, tennis and orchestral music clubs of K-D School micro-dips in depth over 10 dB were found to have incidences between 40% and 53%, and the micro-dips were distributed in frequencies above 5 kHz. In the of kendo, tennis, brass band and tea ceremony clubs of S-D School the incidences of micro-dips ears were between 30% and 48%, and the micro-dips tended to be distributed in higher frequencies except in the tea ceremony club. The micro-dips in the ears of the tea ceremony club members were distributed over all the frequencies examined, but most of them disappeared when counted for dip size above 15 dB remaining an ear at 7.5 kHz. Incidences of earphone or headphone users as a hobby were in the range of 30 to 70% in members of all clubs. There were no characteristic findings of clubs in the incidences of the earphone or headphone users. The degree of association between the micro-dip ears and the use of earphone or headphone was low. C-EOAEs which had a 6 ms or longer duration of evoked otoacoustic emissions were detected with an incidence of 40 to 65% and there was a significant association between the micro-dip ears and the C-EOAE ears. Incidences of spontaneous otoacoustic emissions were between 26% and 28% in all clubs and there were differences in the incidences between sexes. The frequency distribution of the spontaneous otoacoustic emissions were remarkably different to that of the micro-dips. To determine whether the C-EOAEs express a predisposition to inner ear susceptibility to noise-induced hearing loss and to ascertain that the micro-dip is a precursor notice to noise-induced hearing loss, further follow-up surveys are needed.

Antley-Bixler syndrome: a disorder characterized by congenital synostosis of the elbow joint and the cranial suture

The Antley-Bixler syndrome is a rare disorder characterized by craniosynostosis, midface hypoplasia, radiohumeral synostosis, joint contractures, arachnodactyly, and femoral bowing and fractures. We report four cases with this disorder, all of which had craniosynostosis, midface hypoplasia with characteristic facial appearance, and contractures of bilateral elbow joints. However, femoral bowing, fractures, and arachnodactyly were not seen in our patients. In addition, proximal phalanges of the thumb and the great toe showed deformity of the delta phalanx in two cases. Characteristic features in these cases were the synostotic deformity of the elbow joint; three had radioulnahumeral synostosis, and one had radioulnar synostosis. Therefore, our cases indicated that various synostotic patterns of the elbow joints may exist in this syndrome. It is reasonable to propose that characteristic craniofacial appearance associated with the synostosis of the elbow joints of various forms should be considered minimal diagnostic criteria of the Antley-Bixler syndrome.

Changes in significance of axillary lymph node dissection for patients with breast cancer

Axillary lymph node dissection has been a routine part of breast cancer treatment for more than 100 years. As so few patients have been shown to have positive nodes, more consideration should be given to eliminating axillary node dissection for duct carcinoma in situ (DCIS) and T1a lesions. And for patients with T1/2N0M0 cancer of the breast, lumpectomy alone without axillary dissection followed by radiation therapy of the intact breast and regional lymph nodes should be a reasonable treatment without any arm morbidity. Between September 1989 and September 1994, we have treated 40 breast cancer patients with this method and no local recurrence nor distant metastasis has been encountered so far. Therefore, it is concluded that axillary dissection should be performed routinely only for N1b lesions and larger.

Effects of a synthetic vitamin D analog, ED-71, on bone dynamics and strength in cancellous and cortical bone in prednisolone-treated rats

To determine the action of corticosteroid on bone metabolism and assess the effects of a synthetic vitamin D analog, ED-71, on them, 56 SD rats, 8 weeks of age, were assigned to seven groups of eight animals each. Group 1 was the basal control. Group 2 was the nontreated control. Groups 3-7 were given prednisolone at 30 mg/kg of body weight (BW) twice a week and concomitantly administered ED-71 with respective doses of 0, 0.0125, 0.025, 0.05, and 0.1 micrograms/kg of BW for 12 weeks. In group 3, urinary calcium (U-Ca) and deoxypyridinoline (U-Dpy) were significantly increased compared with group 2. In groups 4-7, U-Ca values were increased but U-Dpy values were dose-dependently decreased. Age-dependent increases in the parameter values of BMD, compressive strength, trabecular bone volume (BV/TV), and trabecular thickness (Tb.Th) of the lumbar body were significantly suppressed in group 3 but dose-dependently increased in groups 4-7, and the values of group 7 exceeded those of group 2. The parameters of bone mineral density (BMD) and the bending strength of the femur in groups 4-7 were larger than the values in group 3 but did not reach the levels of group 2. The trabecular bone formation rate (BFR/BS) of the lumbar body measured by calcein labeling in group 3 was reduced when compared with group 2, but the values were not further decreased in groups 4-7. The perimeter ratios of double labels over single labels (dLS/sLS) greatly decreased by prednisolone, were dose-dependently increased to the level of the normal control by ED-71. Double-labeled perimeters and the dLS/sLS ratios were also increased in the periosteal envelope of the midfemur. These findings clearly demonstrate that prednisolone administration affects the age-related changes in bone metabolism, and ED-71 administration counteracts the effects by increasing intestinal calcium absorption, reducing bone resorption, and enhancing mineralization. The action of ED-71, however, seems to be less potent in the cortical bone.

[A case of hepatocellular carcinoma responding to oral administration of 5'-DFUR]

A 65-year-old female patient with liver cirrhosis complicated with hepatocellular carcinoma (HCC) was treated with oral administration of 5'-DFUR (600 mg/day). The titer of serum alpha-fetoprotein gradually decreased, and reduction of the hepatic tumor size was observed by abdominal computed tomography (CT) following 5'-DFUR treatment. HCC was obviously diminished since the start of 5'-DFUR administration and almost disappeared in fifteen months. This case suggests the treatment with 5'-DFUR for hepatocellular carcinoma is completely effective.

Affinity-purified Dermatophagoides farinae antigen induces CD23 on T and B lymphocytes and monocytes specifically in patients with atopic dermatitis

The purpose of this work is to analyze CD23 expression on subpopulations of peripheral blood mononuclear cells (PBMC) from the patients with atopic dermatitis (AD) after stimulation with affinity-purified Dermatophagoides farinae antigen (Af-DF). PBMC from mite-allergic AD patients stimulated with Af-DF induced striking expression of CD23 after the culture. The frequencies of CD23-positive (CD23+) PBMC in the culture were significantly higher than those without stimulation. Most of the CD23+ cells belonged to B lymphocytes and monocytes subsets. CD23 was induced in less than 1% of CD3+, CD4+ and CD8+ lymphocytes by Af-DF. However, significant differences were observed compared to the spontaneous expression, and dose-dependencies were confirmed. No significant increase in the frequencies of CD23+ PBMC was found in non-mite-allergic AD patients and non-atopic donors after stimulation with Af-DF. The kinetics of CD23 expression by Af-DF showed similar patterns to that by IL-4 stimulation. Our results demonstrate that Af-DF can induce CD23 expression on PBMC in mite-allergic AD patients. Based on the high titer of mite-specific IgE antibody in blood of AD, mite antigen may, at least in part, contribute to high CD23 expression in AD.

Suppressive effect of iodine on DMBA-induced breast tumor growth in the rat

Concerning the suppressive effect of inorganic iodine on the growth of 7,12-dimethyl-benz(a)anthracene (DMBA)-induced breast tumor in female Sprague-Dawley (SD) rats, we previously reported that although iodine itself had a suppressive effect on the tumor growth, its effect was not as strong as that of MPA (medroxy-progesterone acetate). However, the combined medication of iodine at a low concentration + MPA showed a stronger effect than MPA alone. The purpose of the present study is to elucidate this mechanism of action by determining the uptake of the administered iodine into breast tumor tissue. Breast tumors were induced with DMBA in female SD rats, and these animals were treated with MPA + inorganic iodine at various concentrations for 4 weeks to determine tumor growth and tumor iodine content. In the comparison of tissue iodine content in growth-suppressive tumors with that in nonsuppressive tumors, the former showed a much higher iodine content. This suggests that direct uptake of inorganic iodine by breast tumors led to the suppression of tumor growth.