Granzyme K- and amphiregulin-expressing cytotoxic T cells and activated extrafollicular B cells are potential drivers of IgG4-related disease

BACKGROUND

IgG4-related disease (IgG4-RD), an example of a type I immune disease, is an immune-mediated fibrotic disorder characterized by dysregulated resolution of severe inflammation and wound healing. However, truly dominant or pathognomonic autoantibodies related to IgG4-RD are not identified.

OBJECTIVE

We sought to perform single-cell RNA sequencing and T-cell receptor and B-cell receptor sequencing to obtain a comprehensive, unbiased view of tissue-infiltrating T and B cells.

METHODS

We performed unbiased single-cell RNA-sequencing analysis for the transcriptome and T-cell receptor sequencing and B-cell receptor sequencing on sorted CD3+ T or CD19+ B cells from affected tissues of patients with IgG4-RD. We also conducted quantitative analyses of CD3+ T-cell and CD19+ B-cell subsets in 68 patients with IgG4-RD and 30 patients with Sjögren syndrome.

RESULTS

Almost all clonally expanded T cells in these lesions were either Granzyme K (GZMK)-expressing CD4+ cytotoxic T cells or GZMK+CD8+ T cells. These GZMK-expressing cytotoxic T cells also expressed amphiregulin and TGF-β but did not express immune checkpoints, and the tissue-infiltrating CD8+ T cells were phenotypically heterogeneous. MKI67+ B cells and IgD-CD27-CD11c-CXCR5- double-negative 3 B cells were clonally expanded and infiltrated affected tissue lesions. GZMK+CD4+ cytotoxic T cells colocalized with MKI67+ B cells in the extrafollicular area from affected tissue sites.

CONCLUSIONS

The above-mentioned cells likely participate in T-B collaborative events, suggesting possible avenues for targeted therapies. Our findings were validated using orthogonal approaches, including multicolor immunofluorescence and the use of comparator disease groups, to support the central role of cytotoxic CD4+ and CD8+ T cells expressing GZMK, amphiregulin, and TGF-β in the pathogenesis of inflammatory fibrotic disorders.

Single-cell transcriptomics reveals granzyme K-expressing cytotoxic Tfh cells in tertiary lymphoid structures in IgG4-RD

BACKGROUND

Germinal center (GC) responses controlled by T follicular helper (Tfh) and T follicular regulatory (Tfr) cells are crucial for the generation of high-affinity antibodies. Acquired immune responses to tissue-released antigens might be mainly induced in tertiary lymphoid organs (TLOs) with GCs in affected tissues. IgG4-related disease (IgG4-RD) demonstrates polarized isotype switching and TLOs in affected tissues. We performed single-cell transcriptomics of tissue-infiltrating T cells from these TLOs to obtain a comprehensive, unbiased view of tissue-infiltrating GC-Tfh cells.

OBJECTIVE

To identify GC-Tfh-cell subsets in TLOs in patients with IgG4-RD using single-cell transcriptomics.

METHODS

Single-cell RNA sequencing of sorted CD3+ T cells and multicolor immunofluorescence analysis were used to investigate CD4+CXCR5+Bcl6+ GC-Tfh cells in affected lesions from patients with IgG4-RD.

RESULTS

Infiltrating CD4+CXCR5+Bcl6+ Tfh cells were divided into 5 main clusters. We detected HLA+ granzyme K+ (GZMK+) Tfh cells with cytotoxicity-associated features in patients with IgG4-RD. We also observed abundant infiltrating Tfr cells with suppressor-associated features in patients with IgG4-RD. These GZMK+ Tfh cells and Tfr cells clustered together in affected tissues from patients with IgG4-RD.

CONCLUSIONS

This single-cell data set revealed a novel subset of HLA+GZMK+ cytotoxic Tfh cells infiltrating affected organs in patients with IgG4-RD, suggesting that infiltrating Tfr cells might suppress cytotoxic Tfh cells.

Immune dysregulation in immunoglobulin G4-related disease

(IgG4-RD) is an immune-mediated fibrotic disorder characterized by severe resolution of inflammation and dysregulation of wound healing. IgG4-RD has been considered a unique disease since 2003, and significant progress has been achieved in the understanding of its essential features. The central role of B cells in IgG4-RD has been demonstrated by the robust clinical responsiveness of IgG4-RD to B cell depletion and the identification of multiple self-antigens that promote B cell expansion. Studies have increasingly revealed critical roles of these B cells and T cells in the pathogenesis of IgG4-RD, and we and other authors further identified CD4⁺ cytotoxic T lymphocytes as the main tissue-infiltrating CD4⁺ T cell subset in IgG4-RD tissues. Additionally, T follicular helper cell subsets that play a role in IgG4 isotype switching have been identified. In this review, we discuss research on IgG4-RD and the roles of B cell and T cell subsets, as well as the functions of CD4⁺ cytotoxic T cells in IgG4-RD pathogenesis. We highlight our findings from ongoing research using single-cell analysis of infiltrating CD4⁺ cytotoxic T cells, CD4⁺ follicular helper T cells, and infiltrating B cells in IgG4-RD and propose a model for the pathogenesis of IgG4-RD.

Distinct disease-specific Tfh cell populations in two different fibrotic diseases: IgG4-related disease and Kimura's disease

BACKGROUND

How T follicular (Tfh) cells contribute to many different B-cell class-switching events during T cell-dependent immune responses has been unclear. Diseases with polarized isotype switching offer a unique opportunity for the exploration of Tfh subsets. Secondary and tertiary lymphoid organs (SLOs and TLOs) in patients with elevated tissue expression levels of IgE (Kimura's disease, KD) and those of IgG4 (IgG4-related disease, IgG4-RD) can provide important insights regarding cytokine expression by Tfh cells.

OBJECTIVE

To identify disease-specific Tfh cell subsets in SLOs and TLOs expressing IL-10 or IL-13 and thus identify different cellular drivers of class switching in two distinct types of fibrotic disorders: allergic fibrosis (driven by type 2 immune cells) and inflammatory fibrosis (driven by cytotoxic T lymphocytes).

METHODS

Single-cell RNA-sequencing, in situ sequencing, and multi-color immunofluorescence analysis was used to investigate B cells, Tfh cells and infiltrating type 2 cells in lesion tissues from patients with KD or IgG4-RD.

RESULTS

Infiltrating Tfh cells in TLOs from IgG4-RD were divided into six main clusters. We encountered abundant infiltrating IL-10-expressing LAG3⁺ Tfh cells in patients with IgG4-RD. Furthermore, we found that infiltrating AID⁺CD19⁺B cells expressing IL-4, IL-10, and IL-21 receptors correlated with IgG4 expression. In contrast, we found that infiltrating IL-13-expressing Tfh cells were abundant in affected tissues from patients with KD. Moreover, we observed few infiltrating IL-13-expressing Tfh cells in tissues from patients with IgG4-RD, despite high serum levels of IgE (but low IgE in the disease lesions). Cytotoxic T cells were abundant in IgG4-RD, and in contrast Type 2 immune cells were abundant in KD.

CONCLUSIONS

This single-cell dataset revealed a novel subset of IL10⁺LAG3⁺Tfh cells infiltrating the affected organs of IgG4-RD patients. In contrast, IL13⁺Tfh cells and type 2 immune cells infiltrated those of KD patients.

Risk Factors for and Management of Postpancreatectomy Hepatic Steatosis

Background:

Relatively little is known about the risk factors and treatments for postpancreatectomy hepatic steatosis.

Methods:

The records of patients who underwent pancreaticoduodenectomy or total pancreatectomy between 2005 and 2010 and were followed up by periodic imaging were reviewed retrospectively. Risk factors and treatment for postpancreatectomy hepatic steatosis were analyzed.

Results:

A total of 253 patients were included in the analysis, including 137 males and 116 females, of median (5, 95 percentile) age 67 (47, 81) years. Of these 253 patients, 75 (29.6%) developed postpancreatectomy hepatic steatosis. Multivariable logistic regression analysis showed that female gender ( p = 0.005; odds ratio: 2.387; 95% confidence interval: 1.293–4.386), body mass index > 22.5 kg/m2 ( p = 0.007; odds ratio: 2.330; 95% confidence interval: 1.261–4.307), operative duration > 540 min ( p = 0.018; odds ratio: 2.286; 95% confidence interval: 1.153–4.533), and delayed gastric emptying ( p < 0.001; odds ratio: 4.598; 95% confidence interval: 1.979–10.678) were independent risk factors associated with postpancreatectomy hepatic steatosis. Treatment consisted of maintenance- or high-dose digestive enzyme replacement therapy. Of patients without obvious tumor recurrence after 6 months, 12 of 15 treated with high dose and only 6 of 35 treated with maintenance-dose digestive enzyme replacement therapy showed improvements in postpancreatectomy hepatic steatosis ( p = 0.006).

Conclusion:

Female gender, obesity, longer operative time, and occurrence of delayed gastric emptying are risk factors for postpancreatectomy hepatic steatosis. High-dose digestive enzyme replacement therapy may improve postpancreatectomy hepatic steatosis.

Anti-Human Immunodeficiency Virus Type 1 Activity of R-95288, a Phosphodiester Hexadeoxyribonucleotide Modified by Dibenzyloxybenzyl and Hydroxyethyl Residues at the 5′- and 3′-Ends

The phosphodiester hexadeoxyribonucleotide R-95288 is a potent anti-human immunodeficiency virus type 1 (HIV-1) agent in vitro which consists or a TGGGAG nucleoside sequence with dibenzyloxybenzyl and hydroxyethyl substituents at the 5′- and 3′-ends, respectively. In this study, the antiviral activity of R-95288 against various strains of HIV-1 in vitro was assessed and its mechanism of action was analysed. R-95288 inhibited replication of all strains of HIV-1 used including laboratory strains with the syncytium-inducing (SI) phenotype and clinical isolates with both SI and non-SI (NSI) phenotypes. The 50% inhibitory concentrations (IC50s) were 0.62–18 μg mL−1 (0.21–6.2 μM). R-95288 inhibited the binding and fusion of HIV-1-infected T cells with CD4+ cells. In addition, R-95288 specifically blocked the binding of monoclonal antibodies, recognizing the anti-V3 loop or the CD4-binding site of the virus envelope glycoprotein gp120. Furthermore, the target site of R-95288 within the V3 loop was found in the putative heparin-binding region by binding inhibition assays using various anti-V3 loop antibodies. These results suggest that R-95288 can inhibit various strains of HIV-1, possibly by specific interaction with gp120.

Femtosecond charge and molecular dynamics of I-containing organic molecules induced by intense X-ray free-electron laser pulses

We studied the electronic and nuclear dynamics of I-containing organic molecules induced by intense hard X-ray pulses at the XFEL facility SACLA in Japan. The interaction with the intense XFEL pulse causes absorption of multiple X-ray photons by the iodine atom, which results in the creation of many electronic vacancies (positive charges) via the sequential electronic relaxation in the iodine, followed by intramolecular charge redistribution. In a previous study we investigated the subsequent fragmentation by Coulomb explosion of the simplest I-substituted hydrocarbon, iodomethane (CH₃I). We carried out three-dimensional momentum correlation measurements of the atomic ions created via Coulomb explosion of the molecule and found that a classical Coulomb explosion model including charge evolution (CCE-CE model), which accounts for the concerted dynamics of nuclear motion and charge creation/charge redistribution, reproduces well the observed momentum correlation maps of fragment ions emitted after XFEL irradiation. Then we extended the study to 5-iodouracil (C₄H₃IN₂O₂, 5-IU), which is a more complex molecule of biological relevance, and confirmed that, in both CH₃I and 5-IU, the charge build-up takes about 10 fs, while the charge is redistributed among atoms within only a few fs. We also adopted a self-consistent charge density-functional based tight-binding (SCC-DFTB) method to treat the fragmentations of highly charged 5-IU ions created by XFEL pulses. Our SCC-DFTB modeling reproduces well the experimental and CCE-CE results. We have also investigated the influence of the nuclear dynamics on the charge redistribution (charge transfer) using nonadiabatic quantum-mechanical molecular dynamics (NAQMD) simulation. The time scale of the charge transfer from the iodine atomic site to the uracil ring induced by nuclear motion turned out to be only ∼5 fs, indicating that, besides the molecular Auger decay in which molecular orbitals delocalized over the iodine site and the uracil ring are involved, the nuclear dynamics also play a role for ultrafast charge redistribution. The present study illustrates that the CCE-CE model as well as the SCC-DFTB method can be used for reconstructing the positions of atoms in motion, in combination with the momentum correlation measurement of the atomic ions created via XFEL-induced Coulomb explosion of molecules.

Sinistral portal hypertension after pancreaticoduodenectomy with splenic vein ligation

BACKGROUND

Splenic vein ligation may result in sinistral (left-sided) portal hypertension and gastrointestinal haemorrhage. The aim of this study was to analyse the pathogenesis of sinistral portal hypertension following splenic vein ligation in pancreaticoduodenectomy.

METHODS

Patients who underwent pancreaticoduodenectomy for pancreatic cancer between January 2005 and December 2012 were included in this retrospective study. The venous flow pattern from the spleen and splenic hypertrophy were examined after surgery.

RESULTS

Of 103 patients who underwent pancreaticoduodenectomy with portal vein resection, 43 had splenic vein ligation. There were two predominant venous flow patterns from the spleen. In the varicose route (27 patients), flow from the spleen passed to colonic varices and/or other varicose veins. In the non-varicose route, flow from the spleen passed through a splenocolonic collateral (14 patients) or a spontaneous splenorenal shunt (2 patients). The varicose route was associated with significantly greater splenic hypertrophy than the non-varicose route (median splenic hypertrophy ratio 1·52 versus 0·94; P < 0·001). All patients with the varicose route had colonic varices, and none had a right colic marginal vein at the hepatic flexure.

CONCLUSION

Pancreaticoduodenectomy with splenic vein ligation may lead to sinistral portal hypertension. To avoid the development of varices, it is important to preserve the right colic marginal vein. Reconstruction of the splenic vein should be considered if the right colic marginal vein is divided.

Liver transection using the LigaSure sealing system

BACKGROUND

The aim of the present study was to evaluate the feasibility and efficacy of the LigaSure vessel sealing system on a large scale when used for liver resection.

METHODS

We retrospectively analyzed the short-term outcomes of 277 patients undergoing hepatectomies with the use of the LigaSure system.

RESULTS

There were two hospital deaths (0.7%), and the morbidity rate was 25.3%. Mean blood loss during liver transection was 352+/-422 ml, and the liver transection speed was 1.9+/-0.86 cm(2)/min. The number of ties required during liver transection was 13.2+/-13. The morbidity and mortality rate was similar when comparing patients with injured livers (chronic hepatitis or cirrhosis) and those with normal livers, but liver transection speed was faster in those with normal livers when compared with those with injured livers (2.00+/-0.88 vs. 1.57+/-0.63 cm(2)/min, p=0.001).

CONCLUSIONS

The LigaSure system can be applied safely in patients undergoing liver resection, regardless of whether cirrhosis is present or not.

Role of host nutrition in symbiont regulation: impact of dietary nitrogen on proliferation of obligate and facultative bacterial endosymbionts of the pea aphid Acyrthosiphon pisum

The impact of host nutrition on symbiont regulation in the pea aphid Acyrthosiphon pisum was investigated. The population density of the obligate symbiont Buchnera aphidicola positively correlated with dietary nitrogen levels. In contrast, the population density of the facultative symbiont Serratia symbiotica increased in aphids reared on low-nitrogen diets, indicating distinct regulatory mechanisms in the same insect host.

[Intralobar pulmonary sequestration with high level of serum CEA; report of a case]

We reported a case of intralobar pulmonary sequestration with a high level of the serum CEA. A 53-year-old woman whose chief complaint was cough was admitted to our hospital. Enhanced chest computed tomography (CT) revealed the mass in the left lower lung, lymph-nodes swelling, and the aberrant artery. Magnetic resonance angiography (MRA) conformed the aberrant artery from the descending aorta. The level of serum CEA elevated at 9.6 ng/ml. Left lower lobectomy was performed. A diagnosis of intralobar pulmonary sequestration (Pryce type II) was established in this case. Histopathologically, the peribronchial epithelial cells in pulmonary sequestration showed weak positive for anti-CEA monoclonal antibody. Postoperative course was uneventful and the serum CEA level was 3.5 ng/ml in the normal range at the postoperative 17th day.

The wide distribution of endornaviruses, large double-stranded RNA replicons with plasmid-like properties

The International Committee on Taxonomy of Viruses (ICTV) recently accepted Endornavirus as a new genus of plant dsRNA virus. We have determined the partial nucleotide sequences of the RNA-dependent RNA polymerase regions from the large dsRNAs (about 14 kbp) isolated from barley (Hordeum vulgare), kidney bean (Phaseolus vulgaris), melon (Cucumis melo), bottle gourd (Lagenaria siceraria), Malabar spinach (Basella alba), seagrass (Zostera marina), and the fungus Helicobasidium mompa. Phylogenetic analyses of these seven dsRNAs indicate that these dsRNAs are new members of the genus Endornavirus that are widely distributed over the plant and fungal kingdoms.

[Pulmonary pleomorphic carcinoma]

Pleomorphic carcinoma is a rare primary pulmonary malignancy. We report 2 surgical cases of pulmonary pleomorphic carcinoma. The first case was a 71-year-old male. Chest computed tomography (CT) showed a rapidly growing tumor with irregular density. Transbronchial lung biopsy revealed the tumor to be malignant. Left lower lobectomy was performed. Pathological diagnosis was pleomorphic carcinoma (pT2N2M0, stage IIIA). He died 8 months after surgery due to brain metastasis and mediastinal lymph node metastasis. The second case was a 74-year-old male who complained of bloody sputum. Chest CT showed a tumor with cavity in the right middle lobe. Brushing cytology under bronchofiberscopy revealed atypical cell. Right middle lobectomy and partial resection of the right lower lobe were performed. Pathological diagnosis was also pleomorphic carcinoma (pT2N0M0, stage IB). He has no findings of recurrence nor metastasis 15 months after the operation.

[Mucoepidermoid carcinoma with high level of serous carcinoembryonic antigen; report of a case]

We reported a case of mucoepidermoid carcinoma with a high level of the serum CEA. A 38-year-old woman was admitted because of abnormal chest shadow. Bronchoscopy revealed polypoid tumor occluding the lumen of right B3 bronchus. Bronchoscopic biopsy suggested a diagnosis of tubular adenocarcinoma. Chest computed tomography (CT) confirmed the mass in the right upper lung field and the swelling of right bronchial lymph node. The CEA level of serum elevated at 12.4 ng/ml. A right upper and middle lobectomy with mediastinal lymph nodes dissection was performed on August 26, 2003. Histopathologically, the polypoid tumor was a low grade mucoepidermoid carcinoma with partially extrabronchial extension. However, no lymph nodes metastasis were noted. The cytoplasms of about 45% of tumor cells showed positive for anti-CEA monoclonal antibody. Pathological stage was IB (T2N0M0). Seventeen months has passed with no evidence of recurrence and the CEA level of serum was in the normal range.

Characterization of a facultative endosymbiotic bacterium of the pea aphid Acyrthosiphon pisum

The pea aphid U-type symbiont (PAUS) was investigated to characterize its microbiological properties. Fluorescence in situ hybridization (FISH) and electron microscopy revealed that PAUS was a rod-shaped bacterium found in three different locations in the body of the pea aphid Acyrthosiphon pisum: sheath cells, secondary mycetocytes, and hemolymph. Artificial transfer experiments revealed that PAUS could establish stable infection and vertical transmission when introduced into uninfected pea aphids. When 28 aphid species collected in Japan were subjected to a diagnostic PCR assay, four species of the subfamily Aphidinae (Aphis citricola, Aphis nerii, Macrosiphum avenae, and Uroleucon giganteus) and a species of the subfamily Pemphiginae (Colopha kansugei) were identified to be PAUS-positive. The sporadic incidences of PAUS infection without reflecting the aphid phylogeny can be best explained by occasional horizontal transfers of the symbiont across aphid lineages.

[Chronic hemorrhagic pyothorax treated with preoperative internal thoracic and intercostal arterial embolization and perioperative non-invasive positive pressure ventilation]

We reported successful surgery for chronic hemorrhagic empyema with severe right heart insufficiency. The preoperative embolization of right internal thoracic artery and intercostals arteries was effective for the control of intraoperative bleeding. Non-invasive positive pressure ventilation (NIPPV) was useful for the perioperative respiratory management. A 62-year-old female with a history of right pneumonectomy and thoracoplasty for pulmonary tuberculosis was admitted because of dyspnea on effort on Dec 5th 2002. Her right heart insufficiency was worsened gradually. On May 20th 2003, we performed the transcatheter embolization of right internal thoracic and intercostals arteries for the control of intraoperative bleeding. The next day, the curettage and fenestration was performed for intraoperative cardiac dysfunction. The intraoperative bleeding was 1,596 ml and operative time was 2 hours 24 minutes. Due to CO2 narcosis, the ventilator under the intratracheal tube was needed for respiratory management in the postoperative course. The switching of the respiratory management with NIPPV from the intratracheal tube during 8 days, her respiratory and general conditions had been improved gradually. Because of methicillin-resistant Staphylococcus aureus (MRSA) infection of thoracic cavity, the radical thoracoplasty following the latissimus dorsi muscules flap and the omentopexy was performed. The operative course was uneventful and she needed overnight NIPPV without O2 inhalation and was discharged.

Aberrant HS1 molecule in a patient with systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is an autoimmune disease characterized by the activation of autoreactive B lymphocytes, which are supposed to carry aberrant signal transduction after the stimulation of B-cell receptor (BCR). To investigate abnormalities in BCR-mediated signaling pathway in lupus B lymphocytes, we analyzed HS1, a molecule downstream of BCR, in 80 Japanese SLE patients. We identified 37 amino acid deletion of HS1 in a 25-year-old female patient, and the aberrant HS1 lacked a part of a functional motif. Analysis of genomic DNA revealed that the aberrant HS1 was caused by exon skipping. Family study showed that the patient as well as her father and sister are heterozygous for the abnormality. WEHI-231 cell, a mouse B cell line, transfected with the aberrant HS1 displayed a significantly increased cell death upon cross-linking of BCR. Additionally, peripheral B lymphocytes from the patient exerted increased apoptosis after BCR stimulation compared to those from control SLE patients. These data suggest that the aberrant HS1 molecule may transmit an accelerated signal after BCR stimulation and may play a role in the activation of autoreactive B lymphocytes.

Histamine regulates T-cell and antibody responses by differential expression of H1 and H2 receptors

Many pathological processes, including those causing allergies and autoimmune diseases, are associated with the presence of specialized subsets of T helper cells (TH1 and TH2) at the site of inflammation. The diversity of TH1 and TH2 function is not predetermined but depends on signals that drive the cells towards either subset. Histamine, released from effector cells (mast cells and basophils) during inflammatory reactions can influence immune response. Here we report that histamine enhances TH1-type responses by triggering the histamine receptor type 1 (H1R), whereas both TH1- and TH2-type responses are negatively regulated by H2R through the activation of different biochemical intracellular signals. In mice, deletion of H1R results in suppression of interferon (IFN)-gamma and dominant secretion of TH2 cytokines (interleukin (IL)-4 and IL-13). Mutant mice lacking H2R showed upregulation of both TH1 and TH2 cytokines. Relevant to T-cell cytokine profiles, mice lacking H1R displayed increased specific antibody response with increased immunoglobulin-epsilon (IgE) and IgG1, IgG2b and IgG3 compared with mice lacking H2R. These findings account for an important regulatory mechanism in the control of inflammatory functions through effector-cell-derived histamine.

Association between blood pressure and insulin resistance in obese females during weight loss and weight rebound phenomenon

The purpose of this study was to investigate the effect of weight loss on blood pressure and its related variables in moderately obese Japanese females, including an investigation of the rebound phenomenon. Study I examined the effects of weight loss on blood pressure in 138 moderately obese, nondiabetic females (BMI 29.3+/-0.3 kg/M2; age, 46.3+/-0.8 years) during a 3-month therapeutic dietary and exercise program. Study II investigated the effect of weight rebound on blood pressure over an additional 21 months of exercise in 48 subjects from Study I subjects. After 3 months, the BMI significantly decreased to 27.9+/-0.3 kg/m2. Abdominal total fat, visceral fat (V), and subcutaneous fat (S) also decreased significantly. In addition, the summation of insulin (sigmaIRI), plasma glucose (sigmaPG) and HOMA during 75 g oral glucose tolerance test also all significantly decreased. Significant decreases in both the SBP and DBP were observed after the 3 month weight reduction program. Multiple regression analysis revealed that the reduction in SBP was significantly and positively associated with the reduction in log sigmaIRI and the reduction in log 24h-urinary norepinephrine excretion at the end of Study I. The DBP showed a significantly positive association with the log sigmaIRI. With regard to the weight rebound phenomenon, Study II showed that the SBP, DBP and sigmaIRI all increased significantly, and a positive correlation was observed between the changes in the SBP and those in the log sigmaIRI. However, no such correlation was observed regarding the abdominal total fat and visceral fat during both periods. These results suggest that weight loss therefore caused the BP to decrease due to both an improvement in hyperinsulinemia and a decrease in the adrenergic activity which may be involved in the urinary catecholamine. As a result, hyperinsulinemia is thus considered to play an important role in the pathogenesis of blood pressure due to obesity not only during weight loss, but also during the weight rebound phenomenon.

Spiroplasma symbiont of the pea aphid, Acyrthosiphon pisum (Insecta: Homoptera)

From a laboratory strain of the pea aphid, Acyrthosiphon pisum, we discovered a previously unknown facultative endosymbiotic bacterium. Molecular phylogenetic analysis based on 16S ribosomal DNA revealed that the bacterium is a member of the genus Spiroplasma. The Spiroplasma organism showed stable vertical transmission through successive generations of the host. Injection of hemolymph from infected insects into uninfected insects established a stable infection in the recipients. The Spiroplasma symbiont exhibited negative effects on growth, reproduction, and longevity of the host, particularly in older adults. Of 58 clonal strains of A. pisum established from natural populations in central Japan, 4 strains possessed the Spiroplasma organism.

Stable inversion method for a polarized-lidar: analysis and simulation

A new inversion inhomogeneous atmosphere (IA) method that is more stable than Fernald's method for two-component (molecule and aerosol) scattering analysis of polarized Mie lidar signals is proposed and examined. The backscattering coefficient and the extinction-to-backscattering ratio (EBR) can be calculated for specified regions at which the depolarization ratio is less than that of molecule without further assumptions. The inversion procedure can be extended to both inward stepwise and outward stepwise integration algorithms. Simulation results indicate that a higher precision was achieved with the IA method than with Fernald's method in terms of error and random noise in estimating boundary value and EBR. Experimental results were also better with the IA method than with Fernald's method.

RNA-dependent RNA polymerase activity associated with endogenous double-stranded RNA in rice

RNA-dependent RNA polymerase (RdRp) activity was detected in the crude microsomal fraction of rice cultured cells that contain a 14 kbp double-stranded RNA (dsRNA). RdRp activity is maximal in the presence of all four nucleotide triphosphates and Mg2+ ion and is resistant to inhibitors of DNA-dependent RNA polymerases (actinomycin D and alpha-amanitin). RdRp activity increases approximately 2.5-fold in the presence of 0.5% deoxycholate. Treatment of purified microsomal fraction with proteinase K plus deoxycholate suggests that the RdRp enzyme complex with its own 14 kb RNA template is located in vesicles. The RdRp enzyme complex was solubilized with Nonidet P-40 and purified by glycerol gradient centrifugation, then exogenous RNA templates were added. Results indicate that exogenous dsRNA reduces RNA synthesis from the endogenous 14 kb RNA template.

The secondary endosymbiotic bacterium of the pea aphid Acyrthosiphon pisum (Insecta: homoptera)

The secondary intracellular symbiotic bacterium (S-symbiont) of the pea aphid Acyrthosiphon pisum was investigated to determine its prevalence among strains, its phylogenetic position, its localization in the host insect, its ultrastructure, and the cytology of the endosymbiotic system. A total of 14 aphid strains were examined, and the S-symbiont was detected in 4 Japanese strains by diagnostic PCR. Two types of eubacterial 16S ribosomal DNA sequences were identified in disymbiotic strains; one of these types was obtained from the primary symbiont Buchnera sp., and the other was obtained from the S-symbiont. In situ hybridization and electron microscopy revealed that the S-symbiont was localized not only in the sheath cells but also in a novel type of cells, the secondary mycetocytes (S-mycetocytes), which have not been found previously in A. pisum. The size and shape of the S-symbiont cells were different when we compared the symbionts in the sheath cells and the symbionts in the S-mycetocytes, indicating that the S-symbiont is pleomorphic under different endosymbiotic conditions. Light microscopy, electron microscopy, and diagnostic PCR revealed unequivocally that the hemocoel is also a normal location for the S-symbiont. Occasional disordered localization of S-symbionts was also observed in adult aphids, suggesting that there has been imperfect host-symbiont coadaptation over the short history of coevolution of these organisms.

Abnormal functional and morphological regulation of the gastric mucosa in histamine H2 receptor-deficient mice

To clarify the physiological roles of histamine H2 receptor (H2R), we have generated histamine H2R-deficient mice by gene targeting. Homozygous mutant mice were viable and fertile without apparent abnormalities and, unexpectedly, showed normal basal gastric pH. However, the H2R-deficient mice exhibited a marked hypertrophy with enlarged folds in gastric mucosa and an elevated serum gastrin level. Immunohistochemical analysis revealed increased numbers of parietal and enterochromaffin-like (ECL) cells. Despite this hypertrophy, parietal cells in mutant mice were significantly smaller than in wild-type mice and contained enlarged secretory canaliculi with a lower density of microvilli and few typical tubulovesicles in the narrow cytoplasm. Induction of gastric acid secretion by histamine or gastrin was completely abolished in the mutant mice, but carbachol still induced acid secretion. The present study clearly demonstrates that H2R-mediated signal(s) are required for cellular homeostasis of the gastric mucosa and normally formed secretory membranes in parietal cells. Moreover, impaired acid secretion due to the absence of H2R could be overcome by the signals from cholinergic receptors.

Phylogenetic analysis of some large double-stranded RNA replicons from plants suggests they evolved from a defective single-stranded RNA virus

Sequences were recently obtained from four double-stranded (ds) RNAs from different plant species. These dsRNAs are not associated with particles and as they appeared not to be horizontally transmitted, they were thought to be a kind of RNA plasmid. Here we report that the RNA-dependent RNA polymerase (RdRp) and helicase domains encoded by these dsRNAs are related to those of viruses of the alpha-like virus supergroup. Recent work on the RdRp sequences of alpha-like viruses raised doubts about their relatedness, but our analyses confirm that almost all the viruses previously assigned to the supergroup are related. Alpha-like viruses have single-stranded (ss) RNA genomes and produce particles, and they are much more diverse than the dsRNAs. This difference in diversity suggests the ssRNA alpha-like virus form is older, and we speculate that the transformation to a dsRNA form began when an ancestral ssRNA virus lost its virion protein gene. The phylogeny of the dsRNAs indicates this transformation was not recent and features of the dsRNA genome structure and translation strategy suggest it is now irreversible. Our analyses also show some dsRNAs from distantly related plants are closely related, indicating they have not strictly co-speciated with their hosts. In view of the affinities of the dsRNAs, we believe they should be classified as viruses and we suggest they be recognized as members of a new virus genus (Endornavirus) and family (Endoviridae).

Molecular characterization of two endogenous double-stranded RNAs in rice and their inheritance by interspecific hybrids

We completely sequenced 13,936 nucleotides (nt) of a double-stranded RNA (dsRNA) of wild rice (W-dsRNA). A single long open reading frame (13,719 nt) containing the conserved motifs of RNA-dependent RNA polymerase and RNA helicase was located in the coding strand. The identity between entire nucleotide sequence of W-dsRNA and that of the dsRNA of temperate japonica rice (J-dsRNA, 13,952 nt) was 75.5%. A site-specific discontinuity (nick) was identified at nt 1,197 from the 5' end of the coding strand of W-dsRNA. This nick is also located at nt 1,211 from the 5' end in the coding strand of J-dsRNA. The dsRNA copy number was increased more than 10-fold in pollen grains of both rice plants. This remarkable increase may be responsible for the highly efficient transmission of J-dsRNA via pollen that we already reported. J-dsRNA and W-dsRNA were also efficiently transmitted to interspecific F1 hybrids. Seed-mediated dsRNA transmission to F2 plants was also highly efficient when the maternal parent was wild rice. The efficiency of dsRNA transmission to F2 plants was reduced when the maternal parent was temperate japonica rice; however, the reduced rates in F2 plants were returned to high levels in F3 plants.

Tissue- and environmental response-specific expression of 10 PP2C transcripts in Mesembryanthemum crystallinum

Ten transcripts (Mpc1-10) homologous to protein phosphatases of the 2C family have been isolated from the halophyte Mesembryanthemum crystallinum (common ice plant). Transcripts range in size from 1.6 to 2.6 kb, and encode proteins whose catalytic domains are between 24% and 62% identical to that of the Arabidopsis PP2C, ABI1. Transcript expression is tissue specific. Two isoforms are present only in roots (Mpc1 and Mpc5), three in young leaves (Mpc6, 8 and 9), two in old leaves (Mpc6 and Mpc8), and two in post-flowering leaves (Mpc8 and Mpc9). Mpc2 is strongly expressed in roots and also in seeds, meristematic tissues and mature flowers. Mpc3 is specific for leaf meristems, and Mpc4 is found in root and leaf meristems. Mpc7 is restricted to meristematic tissues. Mpc10 is only present in mature flowers. Mpc2 (in roots and leaves), Mpc5 (in roots) and Mpc8 (weakly in leaves) are induced by salinity stress and drought conditions with different kinetics in different tissues, but other Mpcs are downregulated by stress. Cold stress (4 degrees C) leads to a decline in Mpc5 and Mp6, but low temperature provoked a long-term (days) increase in Mpc2 levels in leaves and a transient increase (less than 24 h) in roots. Four full-length transcripts have been obtained. In each case, after over-expression in E. coli, the isolated proteins exhibited (Mg2+-dependent, okadeic acid-insensitive) protein phosphatase activity, although activity against 32P-phosphocasein varied among different PP2Cs. Determination of tissue developmental and stress response specificity of PP2C will facilitate functional studies of signal-transducing enzymes in this halophytic organism.

Biologically active oligodeoxyribonucleotides. Part 11: The least phosphate-modification of quadruplex-forming hexadeoxyribonucleotide TGGGAG, bearing 3-and 5-end-modification, with anti-HIV-1 activity

We have found that a hexadeoxyribonucleotide (5'TGGGAG3', R-95288), Koizumi, M. et al. Bioorganic & Medicinal Chemistry, 1997, 5, 2235, bearing a 3,4-dibenzyloxybenzyl (3,4-DBB) group at the 5'-end and a 2-hydroxyethylphosphate at the 3'-end, has high anti-HIV-1 activity and the least cytotoxicity in vitro and in vivo. In order to synthesize more potent hexadeoxyribonucleotides, we substituted phosphodiester (P-O) bonds in the 6-mer with the least phosphorothioate (P-S), phosphoramidate (P-N), or methylphosphonate (P-Me) bonds. When more than two P-N or P-Me bonds were introduced into a 6-mer, the phosphate-modified 6-mers had weak or no anti-HIV- activity, in spite of quadruplex structure formation. However, when P-S bonds were substituted for P-O bonds, anti-HIV-1 activity of their 6-mers did not dramatically decrease, compared with compounds substituted with P-N or P-Me bonds. The results suggest that the formation of a quadruplex structure is not always sufficient for anti-HIV-1 activity of the 6-mer, and that net negative charges derived from P-O or P-S bonds in the quadruplex are important for anti-HIV-1 activity. Moreover, among various phosphate-modified ODNs, we found that the anti-HIV-1 activity of ODN PS7 with only one P-S bond was the same as that of R-95288, both having a high stability in human plasma.

Biologically active oligodeoxyribonucleotides. 5. 5'-End-substituted d(TGGGAG) possesses anti-human immunodeficiency virus type 1 activity by forming a G-quadruplex structure

A series of hexadeoxyribonucleotides (6-mers), d(TGGGAG), substituted with a variety of aromatic groups at the 5'-end were synthesized and tested for anti-human immunodeficiency virus type 1 (HIV-1) activity. While unmodified d(TGGGAG) (31) had no anti-HIV-1 activity, compound 23 with a 3,4-di(benzyloxy)benzyl (DBB) group at the 5'-end potently inhibited the HIV-1IIIB-induced cytopathicity of MT-4 cells in vitro (IC50 = 0.37 microM) without cytotoxicity up to 40 microM. A thermal denaturation study on the 5'-end-substituted 6-mers by means of the circular dichroism (CD) spectra demonstrated that the aromatic substituent attached at the 5'-end of the 6-mer strongly enhanced the formation of a parallel helical structure consisting of four strands (quadruplex). On the contrary, compound 36, in which one of the guanosines of 23 was replaced by a thymidine, did not form a quadruplex, thus exhibiting no anti-HIV-1 activity. Moreover, both compound 15, with a tert-butyldiphenylsilyl group solely at its 3'-end, and compound 21, with a relatively small substituent, a benzyl group, at the 5'-end, formed quadruplexes but had no anti-HIV-1 activity. These findings led us to the conclusion that both the quadruplex structure and the aromatic substituent with adequate size at the 5'-end are crucial for the interaction of the 5'-end-substituted 6-mers with the V3 loop as well as the CD4 binding site on viral gp120, resulting in anti-HIV-1 activity.

Molecular characterization of a single mitochondria-associated double-stranded RNA in the green alga Bryopsis

Mitochondria from the green alga Bryopsis sp. very often contained a 4.5 kb double-stranded RNA (dsRNA) at a defined level. Complementary DNA probes derived from the mitochondrial dsRNA hybridized with none of the algal chloroplast dsRNAs of 1.7 to 2.2 kb, but did hybridize with a similar-sized dsRNA among several dsRNAs from the mitochondria of B. maxima. Sequence analysis of the mitochondrial dsRNA from Bryopsis sp. revealed only two large, overlapping, open reading frames (ORFs) on one strand if UGA was taken as a non-termination codon, suggesting the independent phylogenetic evolution of the mitochondrial dsRNA. Consensus sequence for RNA-dependent RNA polymerase was found within the longer ORF (2472 bp) of the dsRNA. The overlapping 52 bp of the ORFs in different reading frames is suggestive of the occurrence of a -1 ribosomal frameshift in the mitochondrial translation system. The observed simple genetic structures suggest that the algal mitochondrial dsRNA might be deficient in a gene for movement from cell to cell in host plants and, hence, has a plasmid-like nature that is distinct from that of infectious plant viruses. The nature and origin of the endogenous dsRNAs of various sizes and their relationships are discussed.

Biologically active oligodeoxyribonucleotides--IX. Synthesis and anti-HIV-1 activity of hexadeoxyribonucleotides, TGGGAG, bearing 3'- and 5'-end-modification

We have determined that hexadeoxyribonucleotides (5'TGGGAG3'), with modified aromatic groups such as a trityl group at the 5'-end, have anti-HIV-1 activity in vitro. The 6-mer bearing a 3,4-dibenzyloxybenzyl (3,4-DBB) group at the 5'-end had the most potent activity and the least cytotoxicity. When the 3'-end of the 5'-(3,4-DBB)-modified 6-mer was substituted with a 2-hydroxyethylphosphate, a 2-hydroxyethylthiophosphate, or a methylphosphate group at the 3'-end, anti-HIV-1 activity increased. Moreover, among various 3'- and 5'-end-modified 6-mers that were tested, the 6-mer (R-95288) bearing a 3,4-DBB group at the 5'-end and a 2-hydroxyethylphosphate group at the 3'-end was the most stable, when incubated with mouse, rat, or human plasma. Therefore, R-95288 was chosen as the best candidate for possible use in therapy on the basis of its anti-HIV-1 activity.

Protection of hu-PBL-SCID/beige mice from HIV-1 infection by a 6-mer modified oligonucleotide, R-95288

We analyzed the anti-HIV-1 activity of an oligonucleotide derivative, R-95288, in severe combined immunodeficient (SCID/beige) mice transplanted with normal human peripheral blood leukocytes (PBLs), designated hu-PBL-SCID/beige mice. The human chimeric mice were inoculated with HIV-1(CC1) 3 weeks after the transplantation and sacrificed 2 weeks later. Virus infection was determined by coculture of splenocytes with fresh human PBLs and also by detection of HIV- specific DNA sequences using the polymerase chain reaction. No evidence of infection was observed in mice treated with R-95288 (100 mg/kg/day) using intraperitoneal delivery by osmotic minipumps starting 1 day before virus challenge. In contrast, virus infection was observed in over 80% of the saline-treated control mice. In addition, partial inhibition of HIV-1 infection was obtained in mice treated subcutaneously with R-95288 (100 mg/kg/day). Toxicity towards the engrafted human cells was not observed by flow cytometric analysis. Moreover, R-95288 failed to inhibit lymphocyte proliferation (CC50 > 400 microg/ml), while 90% inhibition of HIV-1 replication was achieved at 3.1 microg/ml in vitro. These results suggest the ability of R-95288 to protect the human chimeric mice against HIV-1 infection.

Parabolic mirror optics for collimation of a crescent blue laser beam radiated from channel waveguide Čerenkov second-harmonic generation

Parabolic mirror optics to collimate the crescent-shaped blue laser beam that radiates from Čerenkov second-harmonic generation (SHG) in a channel waveguide configuration is proposed. Mirror collimation optics has a large tolerance to the variations of SHG element parameters, such as the laser source wavelength, as well as to mirror displacement. The anisotropy of a nonlinear crystal in which the waveguide is fabricated has been taken into account. The optimum mirror alignment to obtain a collimated blue laser beam is evaluated in terms of Marechal's criterion. The minimum wave-front aberration with beam intensity weighted is 0.054 λSH. The convergence of the collimated beam is less than 1.6 mrad, and, by using an objective lens, the collimated beam can be focused to a diameter of less than 1 µm, which is 1.27 times the diffraction-limited focusing point.

Emerin deficiency at the nuclear membrane in patients with Emery-Dreifuss muscular dystrophy

Mutations in the STA gene at the Xq28 locus have been found in patients with X-linked Emery-Dreifuss muscular dystrophy (EDMD). This gene encodes a hitherto unknown protein named 'emerin'. To elucidate the subcellular localization of emerin, we raised two antisera against synthetic peptide fragments predicted from emerin cDNA. Using both antisera, we found positive nuclear membrane staining in skeletal, cardiac and smooth muscles in the normal controls and in patients with neuromuscular diseases other than EDMD. In contrast, a deficiency in immunofluorescent staining of skeletal and cardiac muscle from EDMD patients was observed. A 34 kD protein is immunoreactive with the antisera--the protein is equivalent to that predicted for emerin. Together, our findings suggest the specific deficiency of emerin in the nuclear membrane of muscle cells in patients with EDMD.

A severe muscular dystrophy patient with an internally deleted very short (110 kD) dystrophin: presence of the binding site for dystrophin-associated glycoprotein (DAG) may not be enough for physiological function of dystrophin

We report a 4-yr and 5-month-old boy with severe clinical features of an early-onset Duchenne muscular dystrophy, who had a very short (110 kDa) dystrophin at the sarcolemma. The patient had a large deletion (exons 2-44) of the dystrophin gene which was predicted to cause a reading frame shift. Sequence analysis of dystrophin mRNA in muscle revealed an alternatively spliced gene product from exons 1 to 51 that caused restoration of the reading frame, in addition to an mRNA corresponding to the DNA deletion. A consistent result was obtained by immunocytochemical analysis of muscle; i.e. positive staining for dystrophin at the sarcolemma using antibodies against the C-terminus, cysteine-rich region and last three of 24 repeat units of the central rod-domain, but not for the remaining antibodies for dystrophin that recognize the N-terminal and proximal rod-domains. Immunostaining for dystrophin-associated glycoproteins (DAGs: 43 and 50 K) and merosin were preserved. Utrophin staining was positive but fainter than other DMD muscles. These results suggest that an extremely short dystrophin lacking the entire actin-binding site in the N-terminus cannot function properly even if the protein possesses the putative DAG-binding cysteine-rich and the C-terminal domains, and still has an ability to associate with sarcolemmal membrane.

Monoallelic expression of normal mRNA in the PIT1 mutation heterozygotes with normal phenotype and biallelic expression in the abnormal phenotype

The combined deficiency of thyrotropin, growth hormone and prolactin, caused by PIT1 abnormality manifests in the homozygous or heterozygous state. We studied a patient having an allele with Arg271Trp mutation, which produces clinical symptoms in heterozygotes by a dominant-negative effect. However, in the family, her father, grandmother and aunts had the same mutation without clinical symptoms, although the proband had typical phenotypic expression. We analyzed the PIT1 transcript in peripheral lymphocytes by reverse transcription-polymerase chain reaction and found monoallelic expression of normal allele in the father and grandmother and skewed pattern of biallelic expression in the proband. The phenotypic expression of PIT1 abnormality may depend on different transcription of the PIT1 gene.

Decreased myotonin-protein kinase in the skeletal and cardiac muscles in myotonic dystrophy

To investigate the role of myotonin-protein kinase (MT-PK) in the pathophysiology of myotonic dystrophy (DM), we developed specific antibodies against synthetic MT-PK peptides. The antibody identified a 53kDa protein in skeletal muscle and recognized decreases in the amount of the protein in both adult and congenital DM patients, compared with amounts in controls and in patients with other muscle diseases. In cardiac muscle, this antibody identified a 62kDa protein, and in brain, both the 53 and 62kDa proteins were detected. These results suggest the presence of tissue-specific isoforms of MT-PK.

Immunohistochemical analysis of perforin and granzyme A in inflammatory myopathies

Perforin (PF) and granzyme A (GA) are candidates suspected of being cytolytic proteins of the granules of cytotoxic T lymphocytes (CTLs) and natural killer (NK) cells. We analysed PF and GA in muscles from patients with inflammatory myopathies. Five cases of polymyositis (PM), two cases of inclusion body myositis (IBM), and five cases of dermatomyositis (DM) were studied immunohistochemically using anti-PF and GA antibodies raised against each synthetic peptide of human PF and mouse GA, together with a panel of monoclonal antibodies reactive for lymphocyte subsets. In PM and IBM, PF positive cells were colocalized with GA positive cells and occasionally invaded into the non-necrotic muscle fibres. The percentage of PF positive cells among the endomysial CD8 positive cell population was 9.9% (PM) and 12.5% (IBM), and the majority of the endomysial CD8 positive cells were alpha/beta T cells. In contrast, in DM, both PF and GA positive cells were very few in all cases. Only few inflammatory cells were CD16+ or CD57+ NK cells among these diseases. Our results suggest that PF and GA are secreted mainly from alpha/beta T cells, and may play a key role in muscle fibre damage in at least some PM and IBM, but not in DM.

[Dystrophin-related protein in diaphragm, limb and myoblast transferred muscles of mdx mouse]

Expression of the dystrophin-related protein (DRP or Utrophin) was examined with Western blot and immunohistochemical methods in diaphragm, limb and also in myoblast transferred muscles of the mdx mouse. Although we have hypothesized that progressive fibrosis in the diaphragm of the mdx mouse has been due to a smaller amount of DRP expression compared with limb muscles, we could not find any difference in the amount of DRP or in the DRP localization pattern between the two muscle sites. In limb muscles treated with myoblast transfer, dystrophin-positive muscle fibers had no DRP on their surface membrane, although dystrophin-negative muscle fibers were DRP-positive. These findings suggest that excessive expression of DRP is suppressed in the normalized muscle fiber with dystrophin. It also appears that the histological differences seen in the different muscles of the mdx mouse are not due to the amount of DRP present.

Abnormal localization of laminin subunits in muscular dystrophies

To address potential involvement of muscle basal lamina and membrane cytoskeleton proteins in the etiology of non-dystrophinopathy muscular dystrophies, we examined the immunostaining intensity and distribution of laminin subunits (A, B1, B2 and M), type IV collagen, dystrophin and spectrin in skeletal muscle biopsies from 64 myopathic patients (17 Fukuyama congenital muscular dystrophy: FCMD, 13 congenital muscular dystrophy unrelated to FCMD: other CMD, 16 Duchenne muscular dystrophy: DMD, and 18 other neuromuscular diseases. In FCMD muscle, we found a significant reduction of laminin M (merosin; a striated muscle specific basal lamina-associated protein) with approximately 26% of levels seen in controls by quantitative immunofluorescence. Other CMD and DMD muscles showed less dramatic reductions (78%, 80%, respectively). The localization of laminin M was also abnormal in FCMD muscle. Laminin B1 and B2 showed abnormalities similar to those observed with laminin M, but were less marked. Laminin A was only detected in rare regenerating fibers in control biopsies, whereas it was seen around most muscle fibers in FCMD patients, and in dystrophin deficient muscle fibers from DMD patients and its carrier. Staining intensity of type IV collagen in FCMD muscle was not significantly different from the other diseases. These findings may implicate a primary or central role for the basal lamina in FCMD muscle.

Immunoblot analysis of dystrophin-related protein (DRP)

Polyclonal antibodies against the carboxy-terminal portion of dystrophin-related protein (DRP), the putative autosomal gene product which shares sequence homology with dystrophin, show the clear expression of DRP in mouse fetal muscle and in cultured human muscle cells, but not in mature mouse or human muscle. DRP has the same molecular mass as X-linked dystrophin and is recovered from the membrane fraction, but is associated with membranes more loosely than dystrophin.

Dystrophin-related protein in the fetal and denervated skeletal muscles of normal and mdx mice

The amino acid sequence of the polyclonal antibodies we developed against the carboxyl terminus of the dystrophin-related protein, the putative gene product of B3 cDNA, had no homologous sequence to the dystrophin molecule except for two amino acids located at its ends for immunization. By immunohistochemical examination in C57B1/10ScSn and C57B1/10ScSn-mdx mice we found that the DRP was expressed on the surface membrane of fetal muscle fibers, was assembled at the neuromuscular junctions of the mature muscle fibers, and reappeared on the surface membrane of muscle fibers after denervation. Its localization was similar to that of the acetylcholine receptor, suggesting that DRP is one of the cytoskeletons which organize and stabilize the cytoplasmic domain of the acetylcholine receptor.

[Chronological change of EEG findings in a case of pyridoxine dependency seizures]

A patient of pyridoxine dependent seizures was reported. He was born at 34 weeks' gestation and weighted 2,760 g. Apgar scores were 6 and 9 at 1 and 5 minutes, respectively. He showed the first seizure 2 hours after his birth. Phenobarbital, phenytoin, sodium valproate, diazepam and clonazepam were not effective. Pyridoxal phosphate (50 mg) was given intravenously, resulting in suppression of convulsions. However, muscle tonus was severely depressed. In EEG, a discontinuous pattern was found in quiet and indeterminate sleep on the 2nd day of life. At 5th week multifocal spikes were found, and the discontinuous pattern persisted. Ictal discharges at 13th week showed generalized, continuous, irregular and high voltage slow waves with multifocal spikes. At 27th week of life, high voltage slow waves disappeared and multifocal spike discharges decreased. At 2 years and 10 months of age, the patient was suffering from athetotic cerebral palsy and severe mental retardation. Pyridoxal phosphate at the doses of 35-40 mg/kg/day had been administered. Irritability sometimes occurred and additional 50 mg of pyridoxal phosphate controlled this irritability effectively.

Antibody against the C-terminal portion of dystrophin crossreacts with the 400 kDa protein in the pia mater of dystrophin-deficient mdx mouse brain

The mdx mouse is an animal model for X-linked Duchenne muscular dystrophy. A polyclonal antibody against a synthetic peptide IV equivalent to the C-terminal portion (amino acids 3495-3544) of dystrophin crossreacted with a 400 kDa protein in the brain and the spinal cord of mdx mouse, as well as in the control B10 mouse. However, the protein did not crossreact with the polyclonal antibody raised against the N-terminal portion of dystrophin peptide I (amino acids 215-264). Immunofluorescent micrography revealed that the outside of the small arteries and the pia mater of the brain strongly reacted with the anti-peptide IV antibody. These results strongly suggest the presence of a crossreactive protein other than dystrophin, possibly a dystrophin-related autosomal gene product, in the pia mater.

Preparation of protein components exhibiting myosin light chain kinase activities from bovine aorta: discrepancies between its enzyme activity and actomyosin activating effect

1) Two protein components, 155 and 130 kDa in their electrophoretic molecular weights, respectively, were isolated in a homogeneous state from bovine aorta; they showed both the superprecipitation-inducing effect on desensitized natural actomyosin and the myosin light chain kinase (MLCK) action on gizzard myosin. 2) The superprecipitating activity of the 155 kDa component was 5 time higher than that of the 130 kDa component on the basis of equivalent MLCK activity. 3) The same procedure was applied to bovine stomach, giving rise to a 155 kDa component in a homogeneous state as in the case of aorta, but the 130 kDa component thus prepared was contaminated by higher molecular weight components. 4) If compared on the basis of equivalent MLCK activity, bovine stomach 155 kDa component showed more than 10 times higher superprecipitating activity than the fraction that contained the 130 kDa component as the main constituent. 5) The discrepancy between the superprecipitating activity and MLCK activity mentioned above was discussed in relation to the Ca2+ regulation mechanism in smooth muscle contraction. The possibility that the 130 kDa component might be a proteolytic product of the 155 kDa component was also discussed.