P-Tau and Subunit c Mitochondrial ATP Synthase Accumulation in the Central Nervous System of a Woman with Hurler-Scheie Syndrome Treated with Enzyme Replacement Therapy for 12 Years

We report an autopsy case of a woman with mucopolysaccharidosis type I (MPS I) Hurler-Scheie syndrome who was treated with enzyme replacement therapy (ERT) for 12 years. This was the first case of MPS I treated with ERT in Japan. Pathological analysis showed no glycosaminoglycan accumulation in the liver and spleen as a result of long-term ERT, although severe aortic stenosis, diffuse intimal hyperplasia of the coronary artery, and fibrous hypertrophy of the endocardium were observed. Additionally, we detected subunit c mitochondrial ATP synthase (SCMAS) accumulation and mild tauopathy (hyperphosphorylated tau or p-tau, both 3-repeat and 4-repeat tau accumulation) in the same area of the cerebral limbic system and central gray matter of the mid brain and pons. Tauopathy is an important pathological finding in Alzheimer's disease and other neurodegenerative disorders; however, in MPS I, it is unclear whether tauopathy is a primary or secondary phenomenon. Thus, in this report, we describe pathological accumulation of p-tau and SCMAS in the context of MPS I and discuss the mechanisms and importance of these findings in the pathogenesis of MPS I.

Three novel mutations of the MCT8 (SLC16A2) gene: individual and temporal variations of endocrinological and radiological features

We performed genetic analysis and clinical investigations for three patients with suspected monocarboxylate transporter 8 (MCT8) deficiency. On genetic analysis of the MCT8(SLC16A2) gene, novel mutations (c.1333C>A; p.R445S, c.587G>A; p.G196E and c.1063_1064insCTACC; p.R355PfsX64) were identified in each of three patients. Although thyroid function tests (TFTs) showed the typical pattern of MCT8 deficiency at the time of genetic diagnosis in all patients, two patients occasionally were euthyroid. A TRH test revealed low response, exaggerated response and normal response of TSH, respectively. Endocrinological studies showed gonadotropin (Gn) deficiency in two adult patients. On ultrasonography, goiter was detected in one patient. Interestingly, pituitary magnetic resonance imaging (MRI) demonstrated atrophy and thinness of the pituitary gland in two patients. Our findings suggest that thyroid status in patients with MCT8 deficiency varies with time of examination, and repeated TFTs are necessary for patients suspected of MCT8 deficiency before genetic analysis. In addition, it is noteworthy that some variations were observed on the TRH test and ultrasonography of the thyroid gland in the present study. Morphological abnormality of the pituitary gland may be found in some patients, while Gn deficiency should be considered as one of the complications.

[Safety and efficacy of surgical closure of the larynx for recurrent aspiration pneumonia in persons with severe motor and intellectual disabilities: a comparative study with tracheoesophageal diversion]

OBJECTIVE

We retrospectively investigated the efficacy and complications of surgical closure of the larynx (SCL) for recurrent aspiration pneumonia in comparison with tracheoesophageal diversion.

METHODS

The subjects were persons with severe motor and intellectual disabilities (SMID) who had undergone surgery for recurrent aspiration pneumonia between 1994 and 2011: A 8 SCL patients group and a 16 tracheoesophageal diversion patients group. We investigated two groups the lower respiratory infection incidence, length of hospital stay for the surgery, postoperative complications, and rate of cannula withdrawal, by reviewing medical records.

RESULTS

Both the SCL and the tracheoesophageal diversion group showed a reduction in the incidence of infection after surgery, indicating that the efficacy of SCL was equivalent to that of tracheoesophageal diversion in preventing aspiration pneumonea. The SCL group showed a reduction in the length of hospital stay and an increased rate of cannula withdrawal as compared with the tracheoesophageal diversion group.

CONCLUSION

The efficacy of SCL was equivalent to that of tracheoesophageal diversion in preventing aspiration for SMID. We consider SLC to have potential for reducing the burden on patients.

Pathology of the first autopsy case diagnosed as mucolipidosis type III α/β suggesting autophagic dysfunction

Mucolipidosis type III (MLIII) is a mild form of Mucolipidosis type II (MLII, I-cell disease) of late onset, of which almost no pathological study has been reported, as it is a very rare disease. We encountered the case of a 23-year-old man of Japanese and Caucasian mixed parentage diagnosed with MLIII by enzyme assay and genotyping. He died suddenly due to severe dilated cardiomyopathy. On the day after his death, autopsy was performed, and accumulation of Luxol Fast Blue (LFB) positive material was found to be most severe in the neuronal cells of dorsal root ganglions (DRG). Electromicroscopic DRG revealed the neuronal cytoplasm was filled with a zebra-body-like membranous matrix. We tried immunohistochemistry to investigate the mechanism of such accumulation in the DRG that resulted in double positive anti-ubiquitin antibody (FK-2) and anti-LC3 antibody (as specific marker for autophagy) staining, and speculated activating of autophagosome pathway, and 'zebra-body' should be suspected as dysfunctional autophagosome. We also detected foamy cell proliferation in the dura mater, Auerbach's plexus (peripheral nervous system), podocytes of almost all glomeruli, cartilage tissue in lumbar discs, and in cardiac muscle. We tried FK-2 and anti-LC3 antibody staining also for the podocytes, the area with the most marked proliferation of foamy cells, but the result was negative. This led us to speculate that these pathological findings, namely, accumulation of LFB-positive material and foamy fibroblast proliferation, might be the forms of dysfunctional autophagosome at various stages of development. This pathological study of MLIII supports the theory that MLIII is a mild type of MLII because of the close similarity of their pathological findings.

Clinical and genetic study of Japanese patients with type 3 Gaucher disease

Information on the phenotypic variations seen in patients with type 3 (chronic neuronopathic) Gaucher disease (GD) is still limited compared with type 1 GD. We retrospectively investigated the clinical features of 42 Japanese patients with type 3 GD. The 42 patients classified as type 3 fell into two groups: those diagnosed as having type 3 GD at diagnosis (group A; n = 24) and those thought to have type 1 at diagnosis but who later developed neurological symptoms (group B; n = 18). The genotype of group A patients varied widely; however, L444P/L444P and L444P/F213I genotypes accounted for 83% in group B. All the patients who did not receive enzyme replacement with alglucerase or imiglucerase (4 in group A, 2 in group B) died. Nineteen patients received enzyme replacement in group A; however, 7 of these died despite the therapy. On the other hand, 14 patients received enzyme replacement alone in group B and 13 of them survived. Among the ERT-treated patients who survived, only one of 12 in group A and 12 out of 13 in group B can walk unaided. In conclusion, some Japanese GD patients who are thought to have type 1 at diagnosis develop neurological symptoms during their clinical course, and careful observation is essential for patients with characteristic genotypes. Moreover, enzyme replacement alone might not have a sufficient effect on the early onset neurological symptoms in type 3 patients. A different treatment strategy is needed to improve the prognosis of these patients.

Differences in CTG triplet repeat expansion in leukemic cells and normal lymphocytes from a 14-year-old female with congenital myotonic dystrophy

We describe a rare case of acute lymphoblastic leukemia in a 14-year-old female with congenital myotonic dystrophy manifested as mental retardation, extensive contractures of multiple joints of the lower extremities, and severe scoliosis. Because of the potential toxicity of chemotherapy and the patient's poor performance status, a modified chemotherapy regimen was administered. Analysis of the greatly expanded number of CTG repeats at the 3' untranslated region of DMPK gene showed that the number of repeats was 233 greater in leukemic cells than in normal lymphocytes; this elongation may have occurred during the cellular proliferation of leukemic clones.

Successful treatment of Diamond-Blackfan anemia with metoclopramide

Diamond-Blackfan anemia (DBA) is a congenital anemia characterized by a low reticulocyte count, the absence or severe reduction of hemoglobin-containing cells in the bone marrow, and normal megakaryocytic and granulocytic differentiation. Although the anemia may initially respond to corticosteroid therapy, many patients require lifelong red blood cell (RBC) transfusion, leading to infectious complications and iron overload. Metoclopramide has recently been used to treat DBA. Treatment with metoclopramide induces the release of prolactin from the pituitary and stimulates erythropoiesis. For these reasons, we used metoclopramide to treat a 20-year-old man with DBA refractory to low and high doses of corticosteroids, cyclosporin A, and tacrolimus (FK506). The hemoglobin and hematocrit slowly increased, and he has remained asymptomatic and transfusion-independent for 8 months. Metoclopramide therapy should be considered in patients with refractory DBA before treatment-related complications develop.

Brainstem cranial-nerve lesions in an infant with hypoxic cerebral injury

Recent studies have revealed that the brainstem is characteristically involved in hypoxic encephalopathy in infants. However, few reports have described clinical and cranial magnetic resonance findings in detail because most patients with brainstem lesions die during delivery or soon afterward. Reported here is a patient who manifested selective brainstem injury caused by perinatal hypoxic cerebral injury and exhibited palsy of the lower-brainstem cranial nerves. Magnetic resonance imaging was used to demonstrate lesions of brainstem cranial nerves, which were consistent with symptoms of brainstem dysfunction.

Tc-99m MIBG imaging in a huge clinically silent pheochromocytoma with cystic degeneration and massive hemorrhage

I-131 metaiodobenzylguanidine scintigraphy showed marked accumulation in the walls of a clinically silent, huge cystic adrenal mass with a prominent hemorrhage in a 48-year-old man. Although a careful reexamination of the histologic specimen finally lead to a diagnosis of pheochromocytoma, the appearances of this mass on computed tomography and magnetic resonance imaging were not specific for this neoplasm, and even pathologic analysis initially indicated, incorrectly, that this lesion was a hemorrhagic hemangioma. This case shows that I-131 metaiodobenzylguanidine scintigraphy is useful for correctly diagnosing an adrenal mass with prominent cystic or hemorrhagic degeneration.

Tyrosine kinase and phosphatidylinositol 3-kinase activation are required for cyclic adenosine 3',5'-monophosphate-dependent potentiation of deoxyribonucleic acid synthesis induced by insulin-like growth factor-I in FRTL-5 cells

In previous studies, we showed that pretreatment of rat FRTL-5 thyroid cells with TSH, or other agents that increased intracellular cAMP, markedly potentiated DNA synthesis in response to insulin-like growth factor-I (IGF-I). In addition, we found that TSH pretreatment caused an increase in tyrosine phosphorylation of intracellular proteins including an unidentified 125-kDa protein that was well correlated with the TSH-potentiating effect on DNA synthesis induced by IGF-I. These results suggested that cAMP amplified IGF-I-dependent signals for cell growth through changes of cAMP-dependent tyrosine phosphorylation. The present studies were undertaken to determine how tyrosine kinase activation followed by an increase in tyrosine phosphorylation is required for cAMP-dependent potentiation of DNA synthesis induced by IGF-I in this cell line. First of all, we measured tyrosine kinase or protein-tyrosine phosphatase activities in the cell lysates by the in vitro assay. Chronic treatment with TSH or (Bu)2-cAMP stimulated tyrosine kinase activity in the particulate fraction and protein-tyrosine phosphatase activity in the soluble fraction, suggesting that tyrosine kinase plays more important roles for a cAMP-dependent increase in tyrosine phosphorylation of intracellular proteins. The increased tyrosine kinase activity was sensitive to genistein, a potent tyrosine kinase inhibitor. Genistein abolished both the cAMP-dependent increase in tyrosine phosphorylation of the 125-kDa protein and the enhanced DNA synthesis induced by IGF-I in a similar concentration-dependent manner. The only tyrosine-phosphorylated protein associated with the p85 regulatory subunit of phosphatidylinositol (PI) 3-kinase in response to cAMP was 125 kDa. In addition, we found that PI 3-kinase activity bound to p85 subunit significantly increased after (Bu)2cAMP treatment. These results suggested that cAMP stimulates PI 3-kinase through tyrosine phosphorylation of the 125-kDa protein. We then measured DNA synthesis in cells pretreated for 24 h with TSH or (Bu)2cAMP in the absence or presence of LY294002, a PI 3-kinase inhibitor, followed by treatment with IGF-I for 24 h. Presence of LY294002 during TSH or (Bu)2cAMP pretreatment completely abolished cAMP-dependent potentiation of DNA synthesis induced by IGF-I. These results suggest that in FRTL-5 cells cAMP activates genistein-sensitive tyrosine kinases that in turn activate PI 3-kinase activity. These mechanisms appear to be necessary for cAMP-dependent potentiation of the DNA synthesis induced by IGF-I.

Signalling pathways of insulin-like growth factor-I that are augmented by cAMP in FRTL-5 cells

We have reported that pretreatment of rat FRTL-5 thyroid cells with thyrotropin (TSH) markedly potentiates the mitogenic response to insulin-like growth factor-I (IGF-I). The present study was undertaken to determine whether the augmentation by cAMP of IGF-I-dependent tyrosine phosphorylation of known IGF-I receptor substrates plays an important role in the cAMP-dependent potentiation of DNA synthesis induced by IGF-I. Pretreatment with TSH or dibutyryl cAMP did not affect the IGF-I-dependent tyrosine phosphorylation of insulin receptor substrate-1 (IRS-1). In contrast, cAMP pretreatment potentiated the tyrosine phosphorylation of IRS-2 induced by IGF-I, but did not affect the amount of IRS-2. We found that the IGF-I-dependent tyrosine phosphorylation of 66 kDa Shc (Src homology collagen) was markedly increased by cAMP pretreatment, and that this change was mainly due to an increase in the levels of 66 kDa Shc protein. Under these conditions, cAMP pretreatment significantly increased binding of Grb2 (growth-factor-receptor-bound protein 2) to Shc in response to IGF-I, and activation of MAP kinase (mitogen-activated protein kinase) induced by IGF-I was also enhanced by cAMP. The presence of PD98059, an inhibitor of MEK (MAP-kinase/Erk kinase), during treatment with IGF-I partially inhibited the cAMP-dependent augmentation of DNA synthesis in response to IGF-I. On the other hand, cAMP pretreatment increased binding of the phosphoinositide 3-kinase (PI 3-kinase) p85 subunit to IRS-2, which was reflected in PI 3-kinase activity. LY294002, a PI 3-kinase inhibitor, strongly depressed IGF-I-dependent DNA synthesis after pretreatment with and without TSH or dibutyryl cAMP. Our results suggest that the interaction between cAMP-dependent and IGF-I-dependent pathways leads to an augmentation of cell proliferation, which is mediated, at least in part, through the MAP kinase and PI 3-kinase signalling pathways. These effects are mediated by changes in tyrosine phosphorylation of IGF-I receptor substrates, including IRS-2 and Shc.

Alteration of myocardial metaiodobenzylguanidine uptake after treatment of phaeochromocytoma and neuroblastoma

The relationships between changes in myocardial uptake of metaiodobenzylguanidine (MIBG) and those in circulating catecholamines and cardiac function after treatment of phaeochromocytoma and neuroblastoma were evaluated. Iodine-123 or iodine-131 MIBG scintigraphy was performed before and after surgical resection and/or chemotherapy for primary tumours in nine patients with phaeochromocytoma and 13 patients with neuroblastoma. Changes in myocardial MIBG uptake after treatment were estimated by the heart-to-upper mediastinum (H/M) uptake ratios on the images obtained 24 h after MIBG injection, which were compared with serum levels of noradrenaline (NA) and adrenaline (A). Cardiac function was assessed by echocardiography, with measurements of the left ventricular ejection fraction (LVEF). Before treatment, eight patients with phaeochromocytoma and three with neuroblastoma showed poor myocardial MIBG uptake, with highly elevated circulating NA and A. Echocardiography, however, did not show cardiac dysfunction in these patients with the exception of two patients with phaeochromocytoma. With normalization of NA and A levels after treatment, all of these patients except for the two with persistent cardiac dysfunction showed restoration of myocardial MIBG uptake. The H/M ratios increased significantly after treatment in both patient groups, i.e. with phaeochromocytoma and with neuroblastoma (P<0.0001 and P<0.05, respectively), and these ratios correlated inversely with circulating NA and A before and after treatment. By contrast, there was no significant correlation between H/M ratios and LVEF in these two groups. These results indicate that suppression of myocardial MIBG uptake usually may not be related to cardiac dysfunction and may be reversible following normalization of excess catecholamine levels after treatment in patients with neuroadrenergic tumours. However, the suppression may persist in the presence of catecholamine-induced cardiac dysfunction. The assessment of myocardial MIBG uptake can be a helpful adjunct in monitoring the normalization of circulating catecholamine levels and also in identifying the presence of cardiac dysfunction in treated patients with neuroadrenergic tumours.

A novel congenital myopathy with apoptotic changes

We report on a female child with congenital myopathy with delayed developmental milestones and mental retardation. The most striking pathological finding was the presence of many condensed to fragmented myonuclei. DNA fragmentation was confirmed by the TUNEL method and supported by the ultrastructural characteristics of apoptotic nuclear changes. We also demonstrated immunohistochemically the activation of caspase-3 and caspase-9. This appears to be the first reported case of congenital myopathy with apoptotic process.

A euthymic hairless mouse model of Helicobacter pylori colonization and adherence to gastric epithelial cells in vivo

The hairless mouse strain NS:Hr/ICR was examined as a potential small animal model of Helicobacter pylori colonization, adherence to gastric epithelial cells in vivo, and gastritis. Among several small animals tested, NS:Hr/ICR mice proved to be the most highly susceptible to H. pylori infection. Challenge with clinical isolates of H. pylori consisting of either phenotype I or II (VacA and CagA positive and negative, respectively) resulted in colonization by mucus-resident and epithelial cell-adherent bacterial populations. Cell-adherent bacteria resisted 80 cycles of top-speed Vortex washing and were recovered only by homogenization of serially washed glandular stomach tissue, indicating intimate association with the mucosal surface. Immunoperoxidase staining of paraffin sections of gastric tissue from infected mice revealed H. pylori antigens localized in the glandular region of the mucosa, with some colonized areas seen in the vicinity of submucosal mononuclear cell infiltration. The latter inflammatory reaction was observed as a function of the H. pylori phenotype (only type I induced inflammation) and the challenge dose (only those mice challenged with 10(8) CFU or higher showed the reaction). The NS:Hr/ICR strain of mice is a suitable miniature model of H. pylori infection and may prove useful in the quest for an efficacious mode of treatment for this common infection in humans.

Changes in tyrosine phosphorylation of insulin receptor and insulin receptor substrate-1 (IRS-1) and association of p85 of phosphatidylinositol 3-kinase with IRS-1 after feeding in rat liver in vivo

The binding of insulin to its receptor rapidly induces intrinsic insulin receptor tyrosine kinase activity, resulting in tyrosine phosphorylation of various cytosolic substrates, such as insulin receptor substrate-1 (IRS-1) which, in turn, associates with a p85 subunit of phosphatidylinositol 3-kinase (PI 3-kinase) followed by activation of this enzyme. In the present study, we have examined these early steps of insulin signalling in rat liver in vivo after food ingestion. After fasting for 22 h, a 12% casein diet was available ad libitum throughout the 8-h experimental period. Plasma insulin concentrations increased within 45 min after feeding, reached a maximum at 1.5 h and gradually decreased until 8 h. Autophosphorylation of the insulin receptor beta-subunit in liver was detected even during fasting and increased about 1.5-fold at 1.5 h after feeding. Basal tyrosine phosphorylation of IRS-1 was detectable during starvation, increased about twofold at 3 h after feeding and levels were maintained until 8 h. The content of the p85 subunit of PI 3-kinase associated with IRS-1 also increased after feeding in parallel with the changes in tyrosine phosphorylation of IRS-1. Because tyrosine phosphorylation of the insulin receptor beta-subunit and IRS-1 and the association of the p85 subunit of PI 3-kinase with IRS-1 in liver were closely correlated with the changes in the plasma concentration of insulin, we concluded that endogenous insulin secreted in response to eating caused these insulin-dependent intracellular changes in the liver.

Interaction between cAMP-dependent and insulin-dependent signal pathways in tyrosine phosphorylation in primary cultures of rat hepatocytes

The present studies were undertaken to determine whether the interaction between cAMP-dependent and insulin-dependent pathways in primary cultures of rat hepatocytes affects biological functions and tyrosine phosphorylation. Quiescent hepatocytes were pretreated with dibutyryl cAMP or cAMP-generating agents such as glucagon, and then treated or not with insulin. Preincubation for 6 h with dibutyryl cAMP or glucagon enhanced the effect of insulin on DNA synthesis, but not the effect of insulin on amino acid transport or glycogen and protein synthesis. Tyrosine phosphorylation of intracellular proteins was determined by immunoblot analysis using an anti-phosphotyrosine antibody. Maximum tyrosine phosphorylation of a 195 kDa protein, which may be a substrate of insulin receptor kinase, of 175-180 kDa proteins, including insulin receptor substrate (IRS)-1, and of 90-95 kDa proteins, including the insulin receptor beta-subunit, was reached within 30 s of incubation with insulin. Pretreatment for about 3 h with dibutyryl cAMP or cAMP-generating agents clearly increased insulin-dependent tyrosine phosphorylation of the 195 kDa protein, but not IRS-1, IRS-2 or the insulin receptor beta-subunit. Because dibutyryl cAMP and cAMP-generating agents did not increase insulin receptor number or its kinase activity, the effect of cAMP on this potentiation of tyrosine phosphorylation is assumed to be exerted at a step distal to insulin receptor kinase activation. The potentiation by cAMP pretreatment of insulin-stimulated tyrosine phosphorylation may in part be secondary to inhibition of phosphotyrosine phosphatase activity, because cAMP pretreatment blunted the effect of Na3VO4 on the net tyrosine phosphorylation of the 195 kDa protein as compared with cells pretreated with no additive. In summary, the interactions between cAMP-dependent and insulin-dependent pathways that lead to augmentation of DNA synthesis appear to parallel the changes in tyrosine phosphorylation. Further studies will be required to determine whether there is a causal relationship between these phenomena.