Dysferlin mutations in Japanese Miyoshi myopathy: relationship to phenotype

OBJECTIVE

To study dysferlin gene mutations and genotype-phenotype correlations in Japanese patients with Miyoshi myopathy (MM).

BACKGROUND

MM is an autosomal recessive distal muscular dystrophy that arises from mutations in the dysferlin gene. This gene is also mutated in families with limb girdle muscular dystrophy 2B.

METHODS

The authors examined 25 Japanese patients with MM. Genomic DNA was extracted from the peripheral lymphocytes of the patients. The PCR products of each of 55 exons were screened by single strand conformation polymorphism or direct sequencing from the PCR fragments.

RESULTS

The authors identified 16 different mutations in 20 patients with MM; 10 were novel. Mutations in Japanese patients are distributed along the entire length of the gene.

CONCLUSIONS

Four mutations (C1939G, G3370T, 3746delG, and 4870delT) are relatively more prevalent in this population, accounting for 60% of the mutations in this study. This study revealed that the G3370T mutation was associated with milder forms of MM and the G3510A mutation was associated with a more severe form.

Suppression of allergic reaction by lambda-carrageenan: toll-like receptor 4/MyD88-dependent and -independent modulation of immunity

BACKGROUND

Recognition of foreign substances by innate immunity through pattern recognition receptors (PRRs) regulates acquired immunity such as allergic reaction. Because PRRs recognize heterogeneous ligands, daily food intake can potentially regulate immune allergic reaction.

OBJECTIVE

Elucidation of the effect of lambda-carrageenan on allergic reactions was aimed.

METHOD

IFN-gamma and IL-4 was measured in in vitro T cell-stimulated culture. Cytokine production from macrophages in response to lambda-carrageenan was measured as indicator for innate immunity activation. Mice were immunized with OVA in alum to induce specific IgE, and then histamine release was induced by systemic injection of OVA.

RESULTS

Activation of innate immunity by lambda-carrageenan is dependent on Toll-like receptor-4 (TLR4) and MyD88, in which induction of pro-inflammatory cytokines such as TNF-alpha and IL-6 was largely impaired in macrophages from TLR4- and MyD88-deficient mice. Footpad oedema, a model for in vivo inflammatory reactions, was significantly reduced in these mice. Similar to recent evidence showing a preference for the stimulation of Th1 via TLR/MyD88 signalling, lambda-carrageenan showed enhanced IFN-gamma and decreased IL-4 in stimulated T cell cultures. Interestingly, increased IFN-gamma production was still seen in TLR4- and MyD88-deficient splenocytes. Oral administration of lambda-carrageenan to immunized mice successfully decreased OVA-specific IgE, and lambda-carrageenan was also effective in previously immunized mice. Further, serum histamine release upon systemic challenge of OVA was significantly inhibited. Neither OVA-specific IgG1/IgG2a nor cytokine secretion from in vitro cultures were altered, suggesting the involvement of multiple PRRs as demonstrated by TLR4/MyD88-independent IFN-gamma up-regulation. The simultaneous feeding of OVA with lipopolysaccharide abrogated oral tolerance, but lambda-carrageenan was not only devoid of such an effect but was also found to promote oral tolerance in the absence of TLR4.

CONCLUSION

lambda-Carrageenan was suggested to be a useful dietary supplement to ameliorate allergic reactions while maintaining oral tolerance-dependent intestinal homeostasis.

Perioperative course in two cases of tetralogy of fallot with portal venous atresia

We report here two rare surgical cases of tetralogy of Fallot with portal venous atresia. Both patients, previously diagnosed with tetralogy of Fallot, developed portal hypertension and showed hematemesis and/or melena. One patient needed endoscopic sclerotherapy. Intracardiac repair was performed under cardiopulmonary bypass (CPB) with moderate hypothermia. After surgery, one of the patients developed cardiogenic shock due to cardiac tamponade with accumulated chyle in the pericardial sac in the ninth postoperative day, and showed deteriorated liver function, suggesting that liver might have been vulnerable because of the absence of portal blood.

Studies of magnesium in congenital long QT syndrome

We studied the role of magnesium (Mg) in congenital long QT syndrome (LQTS). Twenty-two congenital LQTS patients and 30 control subjects were included in this study. We measured serum Mg (SMg) level and Mg retention (MgR) level, and evaluated the role of Mg (a high MgR level reflects Mg deficiency in the body). The influence of intravenous Mg infusion on Mg level was evaluated. Relatively low SMg level and high MgR level (LQTS:control = 53:33%, p < 0.01) were recognized in congenital LQTS patients, but there was an overlap with controls. Mg supplementation did not shorten QT interval and there was no significant correlation between Mg levels and QTc interval. Patients with syncopal history showed a higher MgR level (syncope (+):syncope (-) = 70:46%, p < 0.01) and intravenous Mg infusion improved Mg deficiency. These results suggest that some (not all) congenital LQTS patients are in a Mg-deficient state, which may be associated with syncope, and Mg supplementation may prevent recurrent syncope in these patients. Because there are several subtypes of congenital LQTS, perhaps with genetic testing Mg deficiency may be identified as a significant cofactor in some forms, whereas in other forms it is not relevant.

Eradication of foot and mouth disease in Japan

An outbreak of foot and mouth disease (FMD) was recorded in Japan in the spring of 2000, the first for ninety-two years. Between 25 March and 11 May, four farms were infected. However, the disease was eradicated without resorting to vaccination, through a campaign of culling, movement control of cloven-hoofed animals in areas surrounding infected premises, and intensive clinical and serological surveillance. Japan regained FMD-free status by the end of September 2000. The authors describe the nature of the outbreaks, the eradication measures implemented, and the clinical and serological surveillance methods used. The possible sources of infection are also examined. Finally, the direct and indirect economic losses are presented.

Localization of nitric oxide synthase activity in unfertilized oocytes and fertilized embryos during preimplantation development in mice

Changes in the activities of nitric oxide synthase (NOS) during embryonic development, and the distribution of endothelial nitric oxide synthase (eNOS) and inducible nitric oxide synthase (iNOS) isoforms were examined in unfertilized mouse oocytes at the second meiotic metaphase (MII) stage and in fertilized mouse embryos during preimplantation development. In addition, the effects of NOS inhibitors on mouse preimplantation development in vitro were investigated. The activities of NOS in MII oocytes and fertilized embryos during the preimplantation period were determined by NADPH-diaphorase staining. Although NOS activity was detected in unfertilized MII oocytes, the intensity of staining was much weaker than that of fertilized embryos at the one-cell stage. There was a decrease in NOS activity in embryos from the four-cell to the eight-cell stage; however, NOS activity increased again in embryos at the morula stage, particularly in the inner cell population. In the expanded blastocysts, staining was confined to the inner cell mass. Immuno-cytochemical staining showed that eNOS and iNOS were expressed in the cytoplasm of oocytes and embryos during the preimplantation period, and eNOS was also distributed in the nuclei of the embryos. When one-cell embryos were treated with 1 mmol N(omega)-nitro-L-arginine methyl ester (L-NAME) l(-1), their development in vitro was arrested at the two-cell stage. This inhibition of development was overcome by the addition of 1 mmol L-arginine l(-1) to the medium. These observations indicate that nitric oxide plays an important role as a diffusible regulator of cell proliferation and differentiation, especially at the developmental transition from the two-cell to the four-cell stage during preimplantation development of mice.

Sex-dependent toxicity of a novel acyl-CoA:cholesterol acyltransferase inhibitor, YIC-C8-434, in relation to sex-specific forms of cytochrome P450 in rats

YIC-C8-434 is a novel inhibitor of acyl coenzyme A:cholesterol acyltransferase (ACAT). To clarify the toxicity of YIC-C8-434, the compound was given orally to Sprague-Dawley rats for 28 days at 0, 4, 20, 100, or 500 mg/kg/day. The toxicity of the drug differed significantly between male and female rats. In female rats treated at 500 mg/kg, many symptoms including moribund condition, suppression of weight gain and food consumption, abnormal blood chemistry, and decreases in organ weights (thymus, ovaries, and uterus) were observed. In male rats by contrast, no significant toxicity was observed at any dose. After a single administration of YIC-C8-434 at 500 mg/kg, female rats had a higher blood concentration of the compound than male rats. Little elimination of YIC-C8-434 was observed in female rats on analysis of drug-elimination kinetics. Furthermore, the metabolism of YIC-C8-434 was analyzed using rat hepatic microsomal preparations from both sexes. Consistent with the observations in vivo, hepatic microsomes from male rats better metabolized YIC-C8-434 than those from females. In addition, the metabolism of YIC-C8-434 by hepatic microsomes from male rats was blocked by SKF525A, a P450 inhibitor. Inhibition experiments using anti-rat CYP1A1, CYP1A2, CYP2B1, CYP2C11, CYP2E1, CYP3A2, and CYP4A1 antisera indicated that CYP3A2 played the predominant role in the metabolism of YIC-C8-434 in rats. Since there is less CYP3A2 in the liver of female than male rats, the involvement of CYP3A2 in YIC-C8-434 metabolism has implications for the sex-related metabolic activity and toxicity of YIC-C8-434.

Development of language in Rett syndrome

Ninety-nine cases of Rett syndrome (RTT) diagnosed clinically (age range 3 years 6 months to 29 years 9 months) were evaluated for the ability of language. The presence of meaningful words, vocabularies, and ages at the start and disappearance of speech were assessed. Phenotype/genotype correlation was evaluated in 22 cases in whom mutations of the genes of methyl-CpG-binding protein 2 (MECP2) existed. Fifty-five cases (55.5%) could speak some words, and of them eight cases (14.5%) spoke two-word sentences. No case had more than 40 words. The vocabularies were mainly bilabial words, known as the characteristics of the initial words in normal children. They began to utter a word between 12 and 48 months, and most of them (85.4%) before 20 months. Those who spoke two-word sentence(s) began to utter a word earlier (10.4+/-3.7 months) than others (17.1+/-9.8 months). Thirty-three cases lost their word(s) in 12-36 months. Among 22 gene-proven cases two cases with mutation of R133C and two cases with R294X had word(s), but another two cases with T158M had not. In RTT a delay in the neuronal systems involved in normal speech development was suggested and its severity seemed to depend on the loci of mutation.

Observation of a (6)(LambdaLambda)He double hypernucleus

A double-hyperfragment event has been found in a hybrid-emulsion experiment. It is identified uniquely as the sequential decay of ( 6)(LambdaLambda)He emitted from a Xi(-) hyperon nuclear capture at rest. The mass of ( 6)(LambdaLambda)He and the Lambda-Lambda interaction energy DeltaB(LambdaLambda) have been measured for the first time devoid of the ambiguities due to the possibilities of excited states. The value of DeltaB(LambdaLambda) is 1.01+/-0.20(+0.18)(-0.11) MeV. This demonstrates that the Lambda-Lambda interaction is weakly attractive.

Lipopolysaccharide stimulates the MyD88-independent pathway and results in activation of IFN-regulatory factor 3 and the expression of a subset of lipopolysaccharide-inducible genes

Bacterial lipopolysaccharide (LPS) triggers innate immune responses through Toll-like receptor (TLR) 4, a member of the TLR family that participates in pathogen recognition. TLRs recruit a cytoplasmic protein, MyD88, upon pathogen recognition, mediating its function for immune responses. Two major pathways for LPS have been suggested in recent studies, which are referred to as MyD88-dependent and -independent pathways. We report in this study the characterization of the MyD88-independent pathway via TLR4. MyD88-deficient cells failed to produce inflammatory cytokines in response to LPS, whereas they responded to LPS by activating IFN-regulatory factor 3 as well as inducing the genes containing IFN-stimulated regulatory elements such as IP-10. In contrast, a lipopeptide that activates TLR2 had no ability to activate IFN-regulatory factor 3. The MyD88-independent pathway was also activated in cells lacking both MyD88 and TNFR-associated factor 6. Thus, TLR4 signaling is composed of at least two distinct pathways, a MyD88-dependent pathway that is critical to the induction of inflammatory cytokines and a MyD88/TNFR-associated factor 6-independent pathway that regulates induction of IP-10.

The role of Toll-like receptors and MyD88 in innate immune responses

Toll-like receptors (TLRs) are phylogenetically conserved receptors that recognize pathogen associated molecular patterns (PAMPS). We previously generated mice lacking TLR2 and TLR4 and showed the differential role of TLR2 and TLR4 in microbial recognition. TLR4 functions as the transmembrane component of the lipopolysaccharide (LPS) receptor, while TLR2 recognizes peptidoglycan from Gram-positive bacteria and lipoprotein. We also generated mice lacking MyD88, an adaptor involved in IL-1R/TLR signalings. The responses to a variety of bacterial components were completely abrogated in MyD88-deficient cells. However, unlike the signaling mediated by other bacterial components such as lipoprotein and bacterial DNA, activation of NF-kappaB and MAP kinases was induced in response to LPS even in the absence of MyD88, which indicates the existence of a MyD88-independent pathway. We have recently found that the MyD88-independent pathway is involved in LPS-induced maturation of dendritic cells (DCs).

Clinical and subclinical acute rejection early after liver transplantation: contributing factors and relevance for the long-term course

Routine transplant aspiration cytology (TAC) after liver transplantation gives detailed information that concerns immunologic events in the graft. TAC can be helpful for diagnosis of acute rejection, but it also detects morphological signs of rejection without clinical correlate ("subclinical rejection"). The aim of this study was to systematically evaluate factors that influence the development of early clinical and subclinical rejection and to analyze the relevance of these early immunologic processes for the long-term course. The study includes the course of 340 patients after liver transplantation between 1988 and 1995 in whom TAC was performed routinely and who were followed for a minimum of 3 years. TAC findings were correlated with the following various clinical parameters: (1) Overall early clinical rejection occurred in 17.4%, subclinical rejection in 59.1%, and no immune activation was seen in 23.5% of patients. (2) Incidence of early clinical and subclinical rejection was markedly influenced by type of immunosuppression. (3) Basic disease and extent of preservation injury had only a minor influence; there was a trend towards lower early rejection associated with more severe preservation damage, increased patient age, and early retransplantation. (4) Presence of early clinical or subclinical rejection was not associated with a higher incidence of chronic dysfunction. (5) Falsely indicated antirejection treatment was associated with inferior graft survival. Subclinical rejection is very frequent early after liver transplantation, requires no treatment, and has no long-term adverse effect. Incidence of early clinical rejection is mainly determined by initial immunosuppression; its occurrence has no negative long-term effects and may even be associated with a lower risk for later immunological complications. Thus, the incidence of early acute rejection is no adequate parameter for evaluating the quality of an immunosuppressive treatment protocol.

Development of endoscopic surgery for the minimally invasive treatment of digestive and other diseases

Minimally invasive surgery has rapidly changed the performance of surgical practice in a wide range of surgical specialities in the last decade of the 20th century. The marked progress in endoscopic surgery has been conducted especially in general and digestive surgery. The Department of Surgery, School of Medicine, Keio University has contributed to the development and establishment of endoscopic surgery in every subspeciality of general and digestive surgery. Our achievements include the development of original methods for laparoscopic wedge gastrectomy and endoscopic thyroidectomy, establishment of surgical techniques in endoscopic surgery for esophageal, gastric, colorectal and hepatobiliary diseases, and the introduction of robotics and tele-communicative technologies to endoscopic surgery.

Characteristics of improved NOVA magnesium ion-selective electrode: changes of ionized magnesium values and reference interval in healthy children

Following the report of interference between the thiocyanate ion (SCN-) and NOVA's previous ion-selective electrode (ISE) for ionized magnesium (iMg2+), NOVA has developed a new ISE which eliminates the effect of SCN-. Two hundred and sixty healthy children were divided into two groups; those who had presented when using NOVA's previous ISE (group A; n = 160) and those using NOVA's new ISE (group B; n = 100). The mean iMg2+ value and the mean iMg2+ percent fraction (iMg2+/serum Mg) were significantly higher in group B than in group A (0.59 +/- 0.03 vs 0.54 +/- 0.03 mmol/L for iMg2+; p < 0.001 and 64.8 +/- 3.1 vs 58.2 +/- 4.1 per cent for iMg2+ percent fraction; p < 0.001). The mean serum SCN- level was 0.023 +/- 0.008 mmol/L in group A (n = 8) and 0.0.21 +/- 0.007 mmol/L in group B (n = 12), and was not significantly different between the two groups. The suspected change of iMg2+ value interfered by SCN- was 0.037 mmol/L in group A. The difference of iMg2+ percent fraction between two groups was higher at high serum magnesium (SMg) levels. The reference interval of iMg2+ was 0.56-0.62 mmo/L in healthy children with the NOVA's new ISE, and was constant irrespective of growth. The NOVA's previous iMg2+ ISE may be interfered with mainly by SCN-. The newly designed ISE eliminated these effects especially at higher SMg levels.

Identification and quantification of chlorinated bisphenol A in wastewater from wastepaper recycling plants

Chlorinated derivatives of bisphenol A were detected in the final effluents of eight paper manufacturing plants in Shizuoka, Japan, where thermal paper and/or other printed paper is used as the raw material. Their amounts were determined by gas chromatography/mass spectrometry (GC/MS) after treatment with N, O-bis(trimethylsilyl)trifluoroacetamide, and ranged from traces to 2.0 microg/l. They are likely produced by chlorination of bisphenol A, which was released into the effluents from the pulping process of wastepaper, during or after bleaching with chlorine.

New avenues in dinitrogen fixation research

The present article focuses on a recent finding concerning dinitrogen fixation by using titanium oxide/conducting polymer composite systems and its comparison with an earlier fixation method (Schrauzer process) that makes use of a powdered titanium oxide. Both processes work under the stimulus of light at room temperature and pressure, but dinitrogen is fixed to a solid ammonium salt crystal in the former and to a gaseous ammonia molecule in the latter process. Differences in the physicochemical concepts between the two processes are discussed.

Sequence heterogeneity of the ten rRNA operons in Clostridium perfringens

We have cloned and sequenced rRNA operons of Clostridium perfringens strain 13 and analyzed the sequence structure in view of the phylogenesis. The organism had ten copies of rRNA operons all of that comprised of 16S, 23S and 5S rDNAs except for one operon. The operons clustered around the origin of replication, ranging within one-third of the whole genome sequence as it is arranged in a circle. Seven operons were transcribed in clockwise direction, and the remaining three were transcribed in counter clockwise direction assuming that the gyrA was transcribed in clockwise direction. Two of the counter clockwise operons contained tRNA(Ile) genes between the 16S and 23S rDNAs, and the other had a tRNA(Ile) genes between the 16S and 23S rDNAs and a tRNA(Asn) gene in the place of the 5S rDNA. Microheterogeneity was found within the rRNA structural genes and spacer regions. The length of each 16S, 23S and 5S rDNA were almost identical among the ten operons, however, the intergenic spacer region of 16S-23S and 23S-5S were variable in the length depending on loci of the rRNA operons on the chromosome. Nucleotide sequences of the helix 19, helix 19a, helix 20 and helix 21 of 23S rDNA were divergent and the diversity appeared to be correlated with the loci of the rRNA operons on the chromosome.

Malignant fibrosarcoma with features of myxoma

Left atrial tumor, diagnosed as myxoma at first investigation, was later demonstrated to be a malignant fibrosarcoma with myxoid change. Myxoma should be diagnosed and managed carefully because of its wide range of histopathologic features.

Two hyperandrogenic adolescent girls with congenital portosystemic shunt

We describe two adolescent girls with a congenital portosystemic shunt who exhibited hyperandrogenism in addition to insulin resistant hyperinsulinaemia. Case 1 was referred to our clinic to undergo a routine clinical work-up prior to tonsillectomy at 14 years of age. Mild liver dysfunction was identified and hypogenesis of the portal vein with a congenital portosystemic shunt diagnosed. Primary amenorrhoea and virilization were evident and an endocrinological evaluation revealed hyperandrogenism and insulin resistant hyperinsulinaemia. Case 2 was referred at 15 years of age because of cardiomegaly. Mild liver dysfunction and hyperbilirubinaemia led to a diagnosis of agenesis of the portal vein with a congenital portosystemic shunt. Virilization was evident and an endocrinological evaluation revealed hyperandrogenism and insulin resistant hyperinsulinaemia. The haemodynamics of these patients were similar to those of secondary portosystemic shunt due to liver cirrhosis, which is often associated with hyperinsulinaemia and/or non-insulin dependent diabetes mellitus. On the other hand, hyperandrogenism is associated with certain insulin-resistant conditions with hyperinsulinaemia, including the polycystic ovary syndrome (PCO). Hyperinsulinaemia is believed to cause hyperandrogenism in patients with PCO by stimulating androgen production in both the ovary and adrenal gland. Therefore, in congenital portosystemic shunts, hyperinsulinaemia is also thought to cause hyperandrogenism due to the same mechanism.

CONCLUSION

A certain percentage of female patients with hyperandrogenism, likely including those with polycystic ovary syndrome may also have congenital portosystemic shunts. Our results indicate that serum levels of total bile acids and ammonia are prognostic indicators of this hepatic vascular anomaly.

Endotoxin-induced maturation of MyD88-deficient dendritic cells

LPS, a major component of the cell wall of Gram-negative bacteria, can induce a variety of biological responses including cytokine production from macrophages, B cell proliferation, and endotoxin shock. All of them were completely abolished in MyD88-deficient mice, indicating the essential role of MyD88 in LPS signaling. However, MyD88-deficient cells still show activation of NF-kappaB and mitogen-activated protein kinase cascades, although the biological significance of this activation is not clear. In this study, we have examined the effects of LPS on dendritic cells (DCs) from wild-type and several mutant mice. LPS-induced cytokine production from DCs was dependent on MyD88. However, LPS could induce functional maturation of MyD88-deficient DCs, including up-regulation of costimulatory molecules and enhancement of APC activity. MyD88-deficient DCs could not mature in response to bacterial DNA, the ligand for Toll-like receptor (TLR)9, indicating that MyD88 is differentially required for TLR family signaling. MyD88-dependent and -independent pathways originate at the intracytoplasmic region of TLR4, because both cytokine induction and functional maturation were abolished in DCs from C3H/HeJ mice carrying the point mutation in the region. Finally, in vivo analysis revealed that MyD88-, but not TLR4-, deficient splenic CD11c(+) DCs could up-regulate their costimulatory molecule expression in response to LPS. Collectively, the present study provides the first evidence that the MyD88-independent pathway downstream of TLR4 can lead to functional DC maturation, which is critical for a link between innate and adaptive immunity.

Expression of cell-matrix molecules and integrin receptors in human liver grafts during chronic rejection

The inflammatory response of immune cells to target cells and cell-matrix molecules is regulated by several receptor-ligand molecules. As fibrosis develops in ongoing chronic rejection after liver transplantation, it is of interest to analyze patterns of integrin receptors and cell-matrix molecules in order to study the relation between immune cells and the stromal and parenchymal cells. In the present study, we demonstrated the expression of these molecules in chronic rejected human liver grafts using immunohistochemical techniques. The results showed a differential expression and induction of integrin receptors and cell-matrix molecules on resident liver cells, especially on sinusoids, reflecting a state of chronic inflammation and a specific interaction between integrin receptors and cell-matrix molecules. The patterns of induced integrin receptors on graft-infiltrating cells was closely related to the local production of cell-matrix molecules and reflected the final sequence of a stepwise progress of the inflammatory reaction.