Distribution and frequencies of PDS (SLC26A4) mutations in Pendred syndrome and nonsyndromic hearing loss associated with enlarged vestibular aqueduct: a unique spectrum of mutations in Japanese

Molecular diagnosis makes a substantial contribution to precise diagnosis, subclassification, prognosis, and selection of therapy. Mutations in the PDS (SLC26A4) gene are known to be responsible for both Pendred syndrome and nonsyndromic hearing loss associated with enlarged vestibular aqueduct, and the molecular confirmation of the PDS gene has become important in the diagnosis of these conditions. In the present study, PDS mutation analysis confirmed that PDS mutations were present and significantly responsible in 90% of Pendred families, and in 78.1% of families with nonsyndromic hearing loss associated with enlarged vestibular aqueduct. Furthermore, variable phenotypic expression by the same combination of mutations indicated that these two conditions are part of a continuous category of disease. Interestingly, the PDS mutation spectrum in Japanese, including the seven novel mutations revealed by this study, is very different from that found in Caucasians. Of the novel mutations detected, 53% were the H723R mutation, suggesting a possible founder effect. Ethnic background is therefore presumably important and should be noted when genetic testing is being performed. The PDS gene mutation spectrum in Japanese may be representative of those in Eastern Asian populations and its elucidation is expected to facilitate the molecular diagnosis of a variety of diseases.     

Bone resorption versus estrogen loss following oophorectomy and menopause

OBJECTIVES: To investigate if menopause and oophorectomy may represent different risk factors for bone resorption/loss. METHODS: The urinary levels of pyridinoline (Pyr) and deoxypyridinoline (D-pyr), the serum levels of type I carboxy-terminal pyridinoline cross-linked telopeptide (ICTP), and lumbar bone mineral density (BMD), were compared in 80 Japanese women after menopause or oophorectomy. These women were divided into four groups of 20 women each as follows: early postmenopausal stage (early physiologic menopause < 3 years before study entry); late postmenopausal stage (physiologic menopause > or = 3 years before study entry); early postoophorectomy stage (oophorectomy < or = 03 years before study entry); or late oophorectomy stage (oophorectomy > 3 years before study entry). RESULTS: Lumbar BMD was significantly lower in the late groups compared to their respective early groups and was lowest in the late postoophorectomy group. The ratio of D-pyr/creatinine (Cr) was not significantly different among the four groups. The ratio of Pyr/Cr was significantly higher in the early postoophorectomy subjects compared with either late group. The serum level of ICTP was significantly higher in the early postoophorectomy group compared to all other groups. CONCLUSIONS: These findings suggest that serum ICTP may be useful in detecting changes in bone resorption after oophorectomy and that women are at greater risk for bone resorption after oophorectomy than after physiologic menopause, although this difference appears to diminish with time.     

Antigenic Characterization of Hantaan and Seoul Virus Nucleocapsid Proteins Expressed by Recombinant Baculovirus: Application of a Truncated Protein, Lacking an Antigenic Region Common to the Two Viruses, as a Serotyping Antigen

Hantaan virus (HTN) and Seoul virus (SEO) are members of the genus Hantavirus in the family Bunyaviridae and are causative agents of hemorrhagic fever with renal syndrome. The complete and truncated nucleocapsid proteins (NP) of HTN and SEO were expressed by a recombinant baculovirus system. Antigenic characterization of the NP using monoclonal antibodies (MAbs) indicated that the binding sites for the serotype-specific MAbs were located between amino acids (aa) 155 and 429. A Western blot assay indicated that the serotype-specific epitopes were conformation dependent. An indirect immunofluorescence antibody (IFA) assay with the truncated NP (aa 155 to 429) was able to distinguish convalescent-phase sera from HTN and SEO patients. However, the antibody titers with the truncated NP were lower than those with the whole NP. The truncated NP of SEO (aa 155 to 429) could be used as an enzyme-linked immunosorbent assay (ELISA) antigen, but the truncated NP from HTN lost its reactivity when used for ELISA. The IFA assay using baculovirus-expressed truncated NP as an antigen is a rapid, simple, and safe test for distinguishing between HTN and SEO infections by serotype.     

Glucose uptake by individual skeletal muscles during running using whole-body positron emission tomography

The purpose of this study was to examine, by positron emission tomography (PET), the distribution of [¹⁸F]fluoro-deoxy-glucose ([¹⁸F]FDG) uptake by human muscles during 35?min of running. Thirteen healthy male subjects were studied, seven of whom participated in the exercise study. Running intensity was kept constant such that the subjects' heart rates were maintained at between 140 and 150?beats per minute. [¹⁸F]FDG [62.9 (14.8)?MBq, mean (SD)] was injected after 15?min of running. PET imaging was started immediately after the running ended. The ratio of [¹⁸F]FDG uptake by muscles in runners to that in control subjects (r-c ratio) varied from three to six for the muscles of the foot and leg below the knee joint. The r-c ratio of the medial head of the gastrocnemius (MG) was higher than that of its lateral head (LG). The r-c ratio of the rectus femoris (RF) was lower than that of the other three muscles of the quadriceps femoris (QF). The r-c ratio of inactive muscles located above the waist was approximately 0.7. These results suggest that, during the moderate running of this study: (1) glucose uptake by muscles of the foot and leg below the knee joint clearly increases, (2) the r-c ratio differs significantly among the skeletal muscles, which act synergistically, and (3) glucose uptake by inactive skeletal muscles decreases.     

Freeze-fracture studies of muscle plasma membranes in myopathic patients with hypo-and hyperthyroidism

To examine the influence of thyroid hormone on the skeletal muscle plasma membrane, we analyzed the changes in ultrastructural architecture and membrane area complexed with digitonin of muscle plasma membrane in myopathic patients with hypo-and hyperthyroidism by the conventional freeze-fracture (F-F) technique and F-F cytochemistry using the sterol-specific ligand digitonin. The densities of flask-shaped invaginations, which are mainly thought to correspond to caveolae, intramembranous particles, and orthogonal arrays, and the changes of digitoninreacted membrane areas in the muscle plasma membranes in three patients with hypothyroid myopathy and one patient with both myasthenia gravis and hyperthyroidism were compared with those in age-matched controls. In the conventional F-F study, the muscle plasma membrane of hypothyroid patients showed increased invagination density, whereas that of the hyperthyroid patient was normal ultrastructurally. In the F-F cytochemistry study, however, the ratio of digitonin-reacted membrane areas versus fractured membrane areas was not different between hypothyroid patients and controls, whereas that of the hyperthyroid patient was lowered in comparison with that of control. These results suggest that thyroid hormone may alter the biochemical properties and ultrastructural architecture of muscle plasma membrane.This study was presented at the 29th annual meeting of the Clinical Electron Microscopy Society of Japan, Sapporo, October 2–3, 1997     

Therapy with nebulized beta2 agonists (procaterol) in asthmatic children: pulmonary function and plasma levels after inhalation]

BACKGROUND: Relationship between post administrative changes in plasma drug levels and bronchodilation remains unknown. In this study, we measured plasma levels of procaterol, a beta2-agonist, when being inhaled through nebulizers in children with bronchial asthma to examine relationship between improvement of pulmonary function and the plasma levels. METHOD: Six asthmatic children with the mean age of 9.8 years, inhaled 0.3 ml of 0.01% procaterol solution through a nebulizer. We examined changes in pulmonary function and plasma procaterol levels before and after inhalation. RESULTS: Procaterol was detected in the plasma 2 minutes after inhalation when it already rose to the maximum level, and kept the steady until showing a decline in 30 minutes. The measured highest value was 87.8+/-45.1 pg/ml. FEV 1.0 remarkably increased 2 minutes after inhalation and was maintained until 60 minutes after inhalation. Other lung function parameters also improved. There was no significant change in the heart rate, but serum potassium concentrations significantly dropped in all patients 60 minutes after inhalation. CONCLUSION: Plasma procaterol levels promptly rose to the peak at 2 minutes after inhalation and decreased 30 minutes later. Improvement of pulmonary function started promptly at minutes after inhalation and it became a peak 60 minutes later.     

Intriguing Case: Endolymphatic Stromal Myosis Coexisting with Adenocarcinoma of the Uterus

Carcinosarcoma of the uterine corpus containing endolymphatic stromal myosis (ESM) is extremely rare. This report describes the light- and electron-microscopic findings of ESM coexisting with adenocarcinoma of the uterus in a 58-year-old female. The polypoid tumor originated from the fundus uteri and filled the uterine cavity. In addition to papillary and medullary acinous adenocarcinoma at the apex of the polypoid mass, the major portion of the tumor specimen was composed of cells resembling endometrial stromal cells that infiltrated the myometrium and lymphatic channels, and a diagnosis of ESM was made due to the relative cell uniformity, rare mitoses, and the presence of invasive growth. There have been few reports on the ultra-structure of ESM and endometrial stromal sarcoma, and there are no reports on the ultrastructural difference between these tumors. In addition to the ultrastructural observations of our case, the electron-microscopic findings of previous reports are discussed.     

TPA-induced cohort migration of well-differentiated human rectal adenocarcinoma cells: cells move in a RGD-dependent manner on fibronectin produced by cells, and phosphorylation of E-cadherin/catenin complex is induced independently of cell-extracellular matrix interactions

 We have already presented a two-dimensional cell motility assay using a highly metastatic variant (L-10) of human rectal adenocarcinoma cell line RCM-1 as a motility model of tumour cells of epithelial origin. In this model, L-10 cells showed locomotion as a coherent sheet when stimulated with 12-O-tetradecanoylphorbol-13-acetate (TPA), and we called this type of movement ”cohort migration”. Electron and immunoelectron microscopic study of the migrating cell sheets demonstrated localized release from cell–cell adhesion only at the lower portion of the cells with loss of E-cadherin immunoreactivity, and this change was associated with increased tyrosine phosphorylation of the E-cadherin–catenin complex, including β-catenin. Cell–extracellular matrix (ECM) interactions involved in this TPA-induced cohort migration and their effect on tyrosine phosphorylation of the E-cadherin-catenin complex have now been investigated. L-10 cell cohort migration was almost completely inhibited by addition of Arg-Gly-Asp (RGD) peptide into the medium, and thus RGD dependent. Cohort migration was stimulated on type I and IV collagens, fibronectin (FN)- and laminin-coated substratum, but was inhibited by RGD only on FN-coated surface. By using immunofluorescent techniques, FN was demonstrated preferentially around migrating cells, and a protein synthesis inhibitor, cycloheximide, inhibited the migration by about 75%. FN produced by L-10 cells were found to be mostly EDA+ FN when analysed by RT-PCR. Moreover, anti-FN antibody, but not anti-vitronectin antibody, inhibited the TPA-induced cohort migration almost completely. Thus, it was likely that L-10 cells produced FN themselves and moved on the FN substrate in an RGD-dependent manner. However, stimulation of migration by type I collagen coating and inhibition by RGD treatment did not affect the tyrosine phosphorylation of the E-cadherin–catenin complex induced by TPA, indicating that cell–cell interactions were adjusted to suit cell migration, irrespective of the condition of cell–ECM adhesion, during TPA-induced cohort migration. Received: 31 December 1997 / Accepted: 2 April 1998     

Immunohistochemistry and angiography in adenomatous hyperplasia and small hepatocellular carcinomas

The sinusoidal structure and blood supply of 38 liver nodules less than 2 cm In diameter were Investigated. There were 18 cases of adenomatous hyperplasia (AH) and 20 cases of hepatocetlular carcinoma (HCC). Growth pattern, encapsulation and vascularity were examined, and Immunohistochemistry performed for factor VIII related antigen (factor VIII), type IV collagen (collagen IV), lamlnln and CD68. There were significant differences between AH and small HCC, except for the expression of CD68. There were differences In tumor size, vasculartty and the components of the basement membrane between AH and small, well differentiated HCC. The cases of AH were supplied by the portal system and maintained the sinusoidal structure, but small well-differentiated HCC were supplied by a mixture of portal and arterial vessels. In spite of their small size, moderately and poorly differentiated HCC had capillary and were supplied by branches of the hepatic artery.