CMAP decrement as a potential diagnostic marker for ALS.

OBJECTIVE: We previously reported that decrement of compound muscle action potential (CMAP) by repetitive nerve stimulation (RNS) was greater in the median nerves than in the ulnar nerves of patients with amyotrophic lateral sclerosis (ALS). The aim of this study was to evaluate whether CMAP decrement by RNS is a feasible marker for the differentiation of ALS from other diseases. MATERIALS & METHODS: We performed RNS in the median and ulnar nerves of 51 patients with ALS and 40 patients with other diseases. RESULTS: The CMAP decrement was significantly greater in the median nerves of patients with ALS, compared to the disease control patients. In the median nerves of patients with ALS, CMAP decrement was significantly greater in the cervical region-onset group than in the other region-onset group. CONCLUSIONS: The finding of CMAP decrement in the median nerves can be useful for differentiating ALS patients with cervical region onset from other controls with active neuropathic diseases.

Long-term survival after liver transplantation in patients with familial amyloid polyneuropathy.

OBJECTIVE: Familial amyloid polyneuropathy (FAP), which is a fatal disorder inherited in an autosomal dominant fashion, is characterized by systemic accumulation of polymerized transthyretin (TTR) in the peripheral nerves and systemic organs. Liver transplantation has become an accepted treatment of this disorder because it stops the major production of amyloidogenic TTR. However, improved survival of transplant patients compared with that of nontransplant patients has not been sufficiently demonstrated. This study investigated whether transplantation improved the long-term outcome of patients by comparing the survival of patients who had transplantations with that of patients who had not had transplantations. METHODS: Eighty consecutive patients with FAP Val30Met who visited Kumamoto University Hospital between January 1990 and December 2010 were studied. The transplant group consisted of 37 patients who had a partial hepatic graft via living donor transplantation in Japan or who underwent liver transplantation in Sweden, Australia, or the United States. The nontransplant group consisted of 43 patients with FAP. Survival was evaluated by using Kaplan-Meier analysis, and the difference in survival was examined via the log-rank test. RESULTS: The transplant group had prolonged survival (p < 0.001) compared with the nontransplant group. The estimated probability of survival at 10 years was 56.1% for the nontransplant group vs 100% for the transplant group. CONCLUSION: Liver transplantation should be considered as an effective treatment in clinical management of patients with FAP Val30Met. CLASSIFICATION OF EVIDENCE: This study provides Class III evidence that liver transplantation prolongs survival in patients with FAP Val30Met.

Effect of liver transplantation on transthyretin Tyr114Cys-related cerebral amyloid angiopathy.

OBJECTIVE: Patients with amyloidogenic transthyretin (ATTR) Tyr114Cys develop amyloid deposits in cerebral blood vessels, cerebral hemorrhage, and rapidly progressive dementia that presents with hereditary cerebral amyloid angiopathy (CAA). However, no treatment has been identified for CAA. Although liver transplantation has become an acceptable treatment of TTR-related amyloidosis, liver transplantation may not successfully treat CNS manifestations of the disorder. In this study, we examined the effect of liver transplantation on these manifestations of TTR-related CAA. METHODS: We compared clinical courses of three patients with CAA associated with ATTR Tyr114Cys who underwent liver transplantation with those of five patients with the disorder who did not undergo liver transplantation. RESULTS: The mortality and occurrence of cerebral hemorrhage and dementia in patients having transplantations were reduced compared with those in patients not having transplantations. The two groups did not differ with regard to the frequency of episodes of fluctuating consciousness and TIAs. The group undergoing transplantations had significantly smaller volumes of intracranial hemorrhage than did the no-transplantation group. CONCLUSION: Liver transplantation was effective for CNS manifestations of cerebral amyloid angiopathy associated with amyloidogenic transthyretin Tyr114Cys.

Diabetes mellitus decreases hippocampal release of neurotransmitters: an in vivo microdialysis study of awake, freely moving rats.

Possible diabetes mellitus-induced changes in hippocampal monoaminergic activities were studied to understand the relationships between neurotransmitter levels and various abnormalities in freely moving diabetic rats. We used both experimentally (STZ rats) and spontaneously diabetic rats (WBN/Kob rats) as the diabetic animal model, and compared the findings with those obtained from non-diabetic rats (C rats). Measurement of neurotransmitters (serotonin and dopamine) was carried out using an in vivo microdialysis method. We found that: 1) the basal level of serotonin in the hippocampus was lowest in WBN rats, followed by STZ rats, then by C rats. The level of serotonin in WBN rats was about a half of that in C rats; 2) the basal level of dopamine was also significantly lower in the diabetic WBN and STZ rats than in C rats. The data show that diabetes mellitus decreases in the monoamine release from the hippocampus in both experimentally and spontaneously diabetic rats.

Direct targeting of cis-Golgi matrix proteins to the Golgi apparatus.

The targeting route of newly synthesized GM130 and GRASP65 to the Golgi apparatus was investigated by three different approaches. First, localization of pulse labeled GM130 and GRASP65 in normal rat kidney (NRK) cells was traced by subcellular fractionation followed by immunoprecipitation. Immediately after the pulse labeling, GM130 and GRASP65 were found in the Golgi but not in the endoplasmic reticulum (ER) membrane fractions, whereas a control Golgi membrane protein was still found in the ER membrane fractions. Second, epitope tagged GM130 and GRASP65 were expressed in NRK cells by plasmid microinjection into the nuclei and their localization was analyzed by immunofluorescence. When ER to Golgi transport was inhibited by prior microinjection of a GTP-restricted mutant of Sar1 protein into the cytosol, the expressed GM130 and GRASP65 showed clear Golgi localization. Last, binding of GM130 and GRASP65 to the membranes was analyzed in vitro. In vitro synthesized GM130 and GRASP65 specifically bound to purified Golgi membranes but not to microsomal membranes. The bound GM130 and GRASP65 were found to form a complex with pre-existing counterparts on the Golgi membrane. These results strongly suggested that GM130 and GRASP65 are directly targeted to the Golgi membrane without initial assembly on the ER and subsequent vesicular transport to the Golgi apparatus.

Identification and characterization of a novel Golgi protein, GCP60, that interacts with the integral membrane protein giantin.

We demonstrated previously that the integral membrane protein giantin has the Golgi localization signal at the COOH-terminal cytoplasmic domain (Misumi, Y., Sohda, M., Tashiro, A., Sato, H., and Ikehara, Y. (2001) J. Biol. Chem. 276, 6867-6873). In the present study, using this domain as bait in the yeast two-hybrid screening system, we identified a novel protein interacting with giantin. The 3.6-kilobase mRNA encoding a 528-amino acid protein of 60 kDa designated GCP60 was ubiquitously expressed and was especially abundant in the testis and ovary. Immunofluorescence and immunoelectron microscopy confirmed that GCP60 was co-localized with giantin in the Golgi complex. GCP60 was found to be a peripheral protein associated with the Golgi membrane, where a COOH-terminal domain of GCP60 interacts with the COOH-terminal cytoplasmic domain of giantin. Overexpression of the COOH-terminal domain of GCP60 caused disassembly of the Golgi structure and blocked protein transport from the endoplasmic reticulum to the Golgi. Taken together, these results suggest that GCP60 is involved in the maintenance of the Golgi structure by interacting with giantin, affecting protein transport between the endoplasmic reticulum and the Golgi.

Postrest contraction in the ventricular papillary muscle of spontaneously diabetic WBN/Kob rat.

In the present study, we investigated the characteristics of the postrest contraction (PRC) in chronic diabetic ventricular muscle. We used WBN/Kob rats of 7-8 weeks as the spontaneously diabetic animal and Wistar rats of 7-8 weeks as the control. We found: (1) No significant differences were seen in the amplitude, the contracting speed, and the relaxing speed of electrically stimulated twitch tension between control and WBN/Kob rats. In addition, the relationship between amplitude of twitch tension and stimulus cycle lengths (0.2-5 sec) was very similar in both animals. (2) The ratios of the first twitch tension (T1) of PRC with various rest intervals (5-600 sec) to the steady-state tension (Tss) were significantly smaller in the diabetic rats than in the controls. (3) When the preparation was stimulated at shorter cycle lengths, the recovery process of PRC was separated into at least two components (fast and slow components). In the diabetic rats, the time constant (tau) of both components was significantly longer than in controls. (4) After caffeine (10(-3) M) treatment, tau of the fast component in the control rats became longer, whereas it remained unchanged in diabetic rats. These findings suggest a dysfunction of the intracellular calcium handling system in spontaneously diabetic heart that is likely to include impaired calcium sequestration and/or extrusion.

Role of furin in delivery of a CTL epitope of an anthrax toxin-fusion protein.

Anthrax toxin lethal factor (LF) in combination with anthrax toxin protective antigen (PA) was endocytosed and translocated to the cytosol of mammalian cells. Residues 1-255 of anthrax toxin lethal factor (LFn) was fused to a cytotoxic T lymphocyte (CTL) epitope of an influenza virus. For processing the toxins, PA must be cleaved into a 63-kDa fragment (PA63) by furin, which is a subtilisin-like processing endo-protease expressed by many eukaryotic cells. To test the ability of cells treated with the LFn fusion protein plus PA to deliver the epitope, CTL assay was performed. Two types of cell lines were identified, one was able to deliver CTL epitope while the other failed to efficiently deliver the epitope. To further elucidate the differences between these cells, the role of furin in these cells was examined. Disruption of the furin gene reduced its ability to deliver the CTL epitope. Furin expression in cells capable of efficiently delivering CTL epitope was quantitatively higher than in cells unable to deliver the epitope. The results suggest that furin plays a critical role in delivery of the CTL epitope of LFn fusion protein.

Biosynthesis and characterization of the brain-specific membrane protein DPPX, a dipeptidyl peptidase IV-related protein.

Dipeptidyl peptidase IV-related protein (DPPX) was found to be preferentially expressed in the brain tissue. We isolated two rat cDNA clones encoding DPPX-S and DPPX-L from a brain cDNA library, of which DPPX-L had a longer sequence at the NH2 terminus. The biosynthesis of DPPXs was examined in both in vitro and in vivo systems. In the cell-free translation system, DPPX-S and DPPX-L were synthesized as 93-kDa and 97-kDa forms, respectively, which are in good agreement with the molecular masses estimated from their primary structure. In COS-1 cells transfected with the cDNAs, DPPX-S and DPPX-L were initially synthesized as 113-kDa and 117-kDa forms, respectively, with high-mannose type oligosaccharides, which were then converted to 115-kDa and 120-kDa forms, mostly with the complex-type sugar chains. Immunofluorescence-microscopic observations confirmed that both DPPXs were expressed on the cell surface. DPPXs were found to have no enzyme activity of DPPIV, even when they were mutated to have the consensus active-site sequence Gly-X-Ser-X-Gly for serine proteases. Immunoblot analysis of samples prepared from various rat tissues demonstrated that DPPX-S, but not DPPX-L, was detectable only in the brain tissue. These results indicate that, of the two isoforms, DPPX-S is preferentially expressed in the brain tissue as the surface glycoprotein without protease activity, although its function remains unknown at present.

An essential cytoplasmic domain for the Golgi localization of coiled-coil proteins with a COOH-terminal membrane anchor.

Giantin is a resident Golgi protein that has an extremely long cytoplasmic domain (about 370 kDa) and is anchored to the Golgi membrane by the COOH-terminal membrane-anchoring domain (CMD) with no luminal extension. We examined the essential domain of giantin required for Golgi localization by mutational analysis. The Golgi localization of giantin was not affected by the deletion of its CMD or by substitution with the CMD of syntaxin-2, a plasma membrane protein. The giantin CMD fused to the cytoplasmic domain of syntaxin-2 could not retain the chimera in the Golgi apparatus. Sequential deletion analysis showed that the COOH-terminal sequence (positions 3059--3161) adjacent to the CMD was the essential domain required for the Golgi localization of giantin. We also examined two other Golgi-resident proteins, golgin-84 and syntaxin-5, with a similar membrane topology as giantin. It was confirmed that the cytoplasmic domain of about 100 residues adjacent to the CMD was required for their Golgi localization. Taken together, these results suggest that the COOH-terminally anchored Golgi proteins with long cytoplasmic extensions have the Golgi localization signal(s) in the cytoplasmic sequence adjacent to the CMD. This is in contrast to previous observations that a transmembrane domain is required for Golgi localization by other Golgi proteins transported from the endoplasmic reticulum.

[A case of inflammatory endotracheal polyps in an asthmatic subject].

A 60-year-old asthmatic woman was admitted to our department because of bloody sputum and pneumonia. She had been treated with inhaled becromethasone dipropionate (800 micrograms/day) on an outpatient basis for 3 years. Fiberoptic bronchoscopy revealed polypoid lesions in the trachea, most of which were removed with forceps during the procedure. Numerous lymphocytes were observed in the biopsy specimen. Because immunohistochemical staining denied a monoclonal origin for the accumulated lymphocytes, the lesion was diagnosed as an inflammatory polyp. The patient was treated successfully with antibiotics for her pneumonia, and on a follow-up bronchoscopy 6 months later, only a small remnant of the lesion was noted. This is the fourth report about inflammatory polyps in asthmatics. In the previous 3 cases, however, marked eosinophil infiltration was consistently reported. The lymphocyte predominance in the present case therefore suggests a distinct etiology rather than asthmatic airway inflammation.

Correlation of diversity of leg morphology in Gryllus bimaculatus (cricket) with divergence in dpp expression pattern during leg development.

Insects can be grouped into mainly two categories, holometabolous and hemimetabolous, according to the extent of their morphological change during metamorphosis. The three thoracic legs, for example, are known to develop through two overtly different pathways: holometabolous insects make legs through their imaginal discs, while hemimetabolous legs develop from their leg buds. Thus, how the molecular mechanisms of leg development differ from each other is an intriguing question. In the holometabolous long-germ insect, these mechanisms have been extensively studied using Drosophila melanogaster. However, little is known about the mechanism in the hemimetabolous insect. Thus, we studied leg development of the hemimetabolous short-germ insect, Gryllus bimaculatus (cricket), focusing on expression patterns of the three key signaling molecules, hedgehog (hh), wingless (wg) and decapentaplegic (dpp), which are essential during leg development in Drosophila. In Gryllus embryos, expression of hh is restricted in the posterior half of each leg bud, while dpp and wg are expressed in the dorsal and ventral sides of its anteroposterior (A/P) boundary, respectively. Their expression patterns are essentially comparable with those of the three genes in Drosophila leg imaginal discs, suggesting the existence of the common mechanism for leg pattern formation. However, we found that expression pattern of dpp was significantly divergent among Gryllus, Schistocerca (grasshopper) and Drosophila embryos, while expression patterns of hh and wg are conserved. Furthermore, the divergence was found between the pro/mesothoracic and metathoracic Gryllus leg buds. These observations imply that the divergence in the dpp expression pattern may correlate with diversity of leg morphology.

[The vanishing testis: diagnosis and histological findings].

PURPOSE: Controversy exists on how to diagnose the vanishing testis and the degree of investigation required. In this series, we reviewed anatomical and histological findings in vanishing testes and investigated the effectiveness of diagnostic laparoscopy and imaging studies. MATERIALS AND METHODS: Between 1974 and March 1999, 107 boys with nonpalpable testis underwent surgery. Of the total, 52 had spermatic vessels, vas deferens, and/or nubbin, and as a result the diagnosis of vanishing testis was made. RESULTS: The affected side of vanishing testis was left 41, right 9 and bilateral 2.35 nubbins were found and the lengths of 24 nubbins were 5 mm or less. Histological examinations were performed in 43 cases including 27 nubbins. From that total, 31 had vas deferens and 11 had epididymis. Only two nubbins had seminiferous tubules but they included no germ cells. The two nubbins were greater than 5 mm long. Laparoscopic surgery was undertaken in 12 separate cases of the vanishing testis and as a result hypoplastic spermatic vessels were present in 7 of the 12 cases. CONCLUSION: The incidence of viable testicular tissue in vanishing testes was 4.7% in our series and it ranges from 0-16% in other series. We submit that one can diagnose the inguinal vanishing testis with preoperative imaging and laparoscopy, and that the nubbin seldom contains testicular tissue. Our results do not support the necessity to remove nubbins.

Molecular cloning and expression of rat antisecretory factor and its intracellular localization.

Antisecretory factor (AF) was identified as a pituitary protein that inhibits the intestinal fluid secretion induced by cholera toxin. One aim of this study was to elucidate whether AF is also synthesized in the intestine or if AF produced in the pituitary is transported to the intestinal tract for its function there. cDNA clones encoding a protein proposed to be AF were isolated from rat pituitary gland and intestinal mucosa cDNA libraries. The nucleotide sequences of clones isolated from the rat pituitary gland and intestinal mucosa were identical. The deduced amino acid sequence was highly homologous to the sequence for subunit 5a of the human 26S protease that exists abundantly in the cytosol and nucleus. The production of AF in the intestine was confirmed by Northern blot and immunoblot analyses. Immunocytochemical observations of cells transfected with the rat AF cDNA showed that the AF protein was localized in the cytoplasm. These findings suggest that the protein proposed to be AF may be a cytoplasmic protein, it exists in the intestine rather than being transported from the pituitary gland, and it may function in intestinal cells.

Intracellular cleavage of glycosylphosphatidylinositol by phospholipase D induces activation of protein kinase Calpha.

Many proteins are anchored to the cell membrane by glycosylphosphatidylinositol (GPI). One of the functions proposed for the GPI anchor is as a possible mediator in signal transduction through its hydrolysis. GPI-specific phospholipase D (GPI-PLD) is a secretory protein that is suggested to be involved in the release of GPI-anchored protein from the membrane. In the present study we examined how GPI-PLD is involved in signal transduction. When introduced exogenously and overexpressed in cells, GPI-PLD cleaved the GPI anchors in the early secretory pathway, possibly in the endoplasmic reticulum, resulting in an increased production of diacylglycerol. Experiments in vitro and in vivo showed that the association of protein kinase Calpha (PKCalpha) with membranes was increased markedly by expression of GPI-PLD in cells. Furthermore, sucrose-density-gradient centrifugation and immunofluorescence microscopy demonstrated that PKCalpha was translocated to the endoplasmic reticulum membrane in cells expressing GPI-PLD, in contrast with its association with the plasma membrane in cells treated with PMA. We also confirmed that the phosphorylation of c-Fos as well as PKCalpha itself was greatly enhanced by the expression of GPI-PLD. Taken together, these results suggest that GPI-PLD is involved in intracellular cleavage of the GPI anchor, which is a new potential source of diacylglycerol production to activate PKCalpha.