Inner ear pathology of alpha-galactosidase A deficient mice,a model of Fabry disease

Objective

Fabry disease is characterized by genetic alpha-galactosidase A deficiency, resulting in accumulation of glycolipids (GL-3) and tissue damage. Hearing loss is also common and attributed to GL-3 accumulation in the inner ear. The only reported histological studies dealt with murine and human specimens. Accordingly, histopathological studies of the cochlea were performed on an alpha-galactosidase A deficient murine model of Fabry disease, using C57BL6/J mice as the controls.

Methods

The hearing ability was evaluated using the ABR threshold, while cochlear specimens were observed light microscopically and ultrathin temporal bone sections by TEM.

Results

HE staining showed no accumulation of GL-3 or abnormal cochlear morphology in the alpha-galactosidase A deficient mice, but toluidine blue staining and TEM revealed GL-3 accumulation in the stria vascularis and kidney. No GL-3 accumulation was detected in the C57BL6/J controls by either HE staining or TEM. The alpha-galactosidase A deficient mice and the controls showed no clear differences in the ABR threshold (hearing acuity), but for older animals the threshold was higher in the C57BL6/J controls.

Conclusion

In summary, although the alpha-galactosidase A deficient mice showed no clear hearing loss, GL-3 accumulation was demonstrated in the cochlea.     

Effect of high-dose lansoprazole on intragastic pH in subjects who are homozygous extensive metabolizers of cytochrome P4502C19.

BACKGROUNDS AND AIM: Lansoprazole is mainly metabolized by cytochrome P4502C19 (CYP2C19) in the liver. The effect of lansoprazole is assumed to be insufficient in subjects who are homozygous extensive metabolizers of CYP2C19. This study aimed to examine whether the CYP2C19 genotype status affected the acid-inhibitory effects of lansoprazole and to develop a strategy to overcome this pharmacogenetic problem. METHODS: Eighteen Helicobacter pylori-negative healthy volunteers, whose CYP2C19 genotypic status had been assessed, participated in the study. They consisted of 7 subjects who were homozygous extensive metabolizers, 7 subjects who were heterozygous extensive metabolizers, and 4 subjects who were poor metabolizers of CYP2C19, who took a placebo or lansoprazole 30 mg once daily in the morning for 8 days. On day 8 of dosing, 24-hour intragastric pH values were recorded. Five of the homozygous extensive metabolizer subjects underwent the 24-hour intragastric pH monitoring on day 8 of dosing of lansoprazole 30 mg 4 times daily. RESULTS: When lansoprazole 30 mg was given once daily, the mean 24-hour intragastric pH values in the subjects who were homozygous extensive metabolizers, heterozygous extensive metabolizers, and poor metabolizers were 4.5, 4.9, and 5.5, respectively (P <.005). On day 8 of dosing of lansoprazole 30 mg 4 times daily in subjects who were homozygous extensive metabolizers, the mean 24-hour intragastric pH value was 7.4. CONCLUSION: The effect of lansoprazole on intragastric pH depended significantly on CYP2C19 genotype status. Complete acid inhibition could be achieved by the frequent administration of lansoprazole (eg, 30 mg 4 times daily) in subjects who were homozygous extensive metabolizers. A genotyping test of CYP2C19 status appears useful for prescribing an optimal dosing scheme of lansoprazole.     

Cytoplasmic Inclusion Bodies and Minimal Hepatitis: Fibrinogen Storage without Hypofibrinogenemia

A 12-year-old Japanese boy had chronic elevation and fluctuation of serum transaminase levels since infancy, with no signs or symptoms of liver failure. Usual infections or metabolic disorders were eliminated from consideration. No coagulopathy or abnormality in plasma concentrations of clotting factors was found. Light microscopy of liver biopsy specimens obtained at ages 2, 5, and 7 years showed slight hepatocyte disarray and minimal mononuclear-leukocyte lobular inflammation, with eosinophilic inclusion bodies in the cytoplasm of hepatocytes throughout the lobule. These bodies stained with the periodic acid-Schiff (PAS) technique; the PAS-positive material was partly diastase digestible and on immunostaining marked for fibrinogen but not for α₁-antitrypsin. On transmission electron microscopy, the bodies were represented by finely granular material contained within membranes and were interpreted as tentatively endoplasmic reticulum. Fibrinogen storage may be manifest as minimal hepatitis without coagulopathy. Received August 12, 1999; accepted June 27, 2000.     

Truncated Hantavirus Nucleocapsid Proteins for Serotyping Hantaan, Seoul, and Dobrava Hantavirus Infections

Truncated recombinant nucleocapsid proteins (rNPs) of Hantaan virus (HTNV), Seoul virus (SEOV), and Dobrava virus (DOBV) were expressed by a baculovirus system. The truncated rNPs, which lacked 49 (rNP50) or 154 (rNP155) N-terminal amino acids of the NPs of HTNV, SEOV, and DOBV, were able to differentiate HTNV-, SEOV-, and DOBV-specific immune sera. Recombinant NP50s retained higher reactivities than rNP155s and were proven useful for enzyme-linked immunosorbent assay (ELISA). The ELISAs based on the rNP50s of HTNV, SEOV, and DOBV successfully differentiated three groups of patient sera, previously defined by neutralization tests: 17 with HTNV infection, 12 with SEOV infection, and 20 with DOBV infection. The entire rNP of Puumala virus (PUUV) distinguished PUUV infection from the other types of hantavirus infection. Serotyping with these rNP50s can be recommended as a rapid and efficient system for hantavirus diagnosis.     

Pulmonary infarction caused by the spontaneous migration of the vena caval tumor thrombus of right renal cell carcinoma: a case report]

A 70-year-old male with right renal mass incidentally found by annual check-up using ultrasound, was referred to Department of Urology, Jikei University Affiliated Kashiwa Hospital. He was diagnosed as having right renal cell carcinoma with vena caval tumor thrombus extending above the diaphragm (T3c) preoperatively. The day before the scheduled day of operation, right pulmonary infarction caused by spontaneous migration of vena caval tumor thrombus of right renal cell carcinoma developed. Although arterial blood gas findings were poor, he only had low grade chest pain without shock. Therefore, we successfully performed right radical nephrectomy and thrombectomy of right pulmonary artery the next day. He was discharged 42 days postoperatively, but, he died from acute heart failure 9 months after the operation.     

Autonomic insufficiency as a factor contributing to dialysis-induced hypotension.

BACKGROUND: Autonomic insufficiency is considered a factor that contributes to dialysis-induced hypotension (DIH). However, the relationship between the two conditions has not been fully elucidated. METHODS: We investigated 44 haemodialysis patients using [(123)I]-meta-iodobenzylguanidine (MIBG) scintigraphy and power-spectral analysis (PSA) of heart rate variability. The patients were divided into four groups: a diabetic group with DIH, a diabetic group without DIH, a non-diabetic group with DIH, and a non-diabetic group without DIH. In these groups the heart to mediastinum average count rate (H/M), MIBG washout rate, and low- and high-frequency components of PSA were compared. RESULTS: From the [(123)I]-MIBG scintigraphy, for both early and delayed images, H/M of the groups with DIH were lower than in groups without DIH, in both diabetics and non-diabetics (P<0.05). For the early images, H/M of the diabetic groups were lower than in the non-diabetic groups, in the groups both with and without DIH (P<0.01). For the delayed images, H/M of the diabetic group was lower than in the non-diabetic group, in the groups with DIH (P<0.05). The MIBG washout rate was the highest in the diabetic group with DIH (P<0.05 vs diabetic and non-diabetic groups without DIH). The PSA of heart rate variability showed a good discrimination of the low-frequency component between the non-diabetic patients with and without DIH (P<0.05). Mean ultrafiltration volume and its rate were not different among the four groups. CONCLUSION: Autonomic insufficiency is more severe in patients with DIH than in those without, and its degree may be enhanced in diabetic patients. For the management of DIH, special care should be addressed not only to dry weight but also to autonomic insufficiency.     

Nicotinamide Adenine Dinucleotide-Dependent Retinoic Acid Formation From Retinol in the Human Gastric Mucosa: Inhibition by Ethanol, Acetaldehyde, and H2 Blockers

All-trans retinoic acid formation from all-trans retinol (vitamin A) in the human gastric mucosa was studied. When all-trans retinol and the human gastric mucosa were incubated together, all-trans retinoic acid was formed in the presence of nicotinamide adenine dinucleotide (NAD). When the NAD was not added, hardly any formation was observed. The formation of all-trans retinoic acid tended to be attenuated by 10 mM ethanol. Moreover, it was significantly attenuated in a concentration-dependent manner by ethanol at concentrations of 100 mM and above. Acetaldehyde at concentrations of 50 μM and above also significantly attenuated its formation in a concentration-dependent manner. Some H2 blockers, which include ranitidine hydrochloride and cimetidine, significantly attenuated the formation of all-trans retinoic acid, whereas famotidine failed to suppress it. There is an NAD-dependent pathway by which all-trans retinoic acid is produced from all-trans retinol in the human gastric mucosa. Inhibitors of alcohol dehydrogenase, which include ethanol and some H2 blockers, and of aldehyde dehydrogenase, which include acetaldehyde, inhibit its production.     

Values of the bispectral index do not parallel the hemodynamic response to the rapid increase in isoflurane concentration

PURPOSE: To investigate the changes in hemodynamic variables and bispectral index (BIS) in response to a rapid increase in isoflurane or sevoflurane concentration. METHOD: Thirty adult patients were anesthetized with either isoflurane (isoflurane group) or sevoflurane (sevoflurane group). Two minutes after induction of anesthesia with thiamylal, the inspired concentrations of isoflurane and sevoflurane were rapidly increased from 0.5 minimum alveolar anaesthetic concentration (MAC) to 3 MAC and maintained for five minutes. Heart rate (HR), mean arterial pressure (MAP), and BIS were measured every minute. RESULTS: An increase in the anesthetic concentration caused increases in HR and MAP in the isoflurane group and a decrease in MAP in the sevoflurane group. Consequently, HR and MAP in the isoflurane group were significantly higher than those in the sevoflurane group. After inhalation of high concentrations, BIS significantly and progressively decreased in both groups. CONCLUSION: BIS values decrease after a step increase in volatile agent concentration, whether or not a hyperdynamic action occurs.     

Experimental Study Using Heparin‐Immobilized Adsorbent of EDA(+)fibronectin

Abstract: EDA(+)fibronectin, which might participate in the pathogenesis and/or progress of immune diseases, is efficiently removed from plasma by cryofiltration; however, cryofiltration removes not only EDA(+)fibronectin, but also other proteins. We thus developed a new adsorbent by using its high affinity with heparin. The purpose of this study was to evaluate the efficacy of the adsorbent of EDA(+)fibronectin (OHC‐20) in experimental arthritis. The experimental arthritis was induced by injection of 0.5 mg of Mycobacterium butyricum in Lewis rats. Rats were divided into 4 groups; 1 nontreatment group, and 3 treatment groups. Adsorption therapy in treatment groups was performed three times: on Days 1, 3, and 5 in Group A; Days 7, 9, and 11 in Group B; and Days 13, 15, and 17 in Group C. The walking postures of rats improved from dragging to walking on tiptoe, and the increase of hind‐foot volume was suppressed in Groups B and C. We conclude that heparin‐immobilized adsorbent might be promising for immune diseases.     

Immunocytochemical localization of candidates for vesicular glutamate transporters in the rat cerebral cortex.

Brain-specific Na(+)-dependent inorganic phosphate cotransporter (BNPI) was recently reported to serve as a vesicular glutamate transporter (VGluT), and was renamed VGluT1 (Bellocchio et al. [ 2000] Science 289:957-960; Takamori et al. [2000] Nature 407:189-194). Ahead of these reports, cDNA encoding another brain-specific inorganic phosphate transporter, which showed 82% amino acid identity to VGluT1, was cloned and designated differentiation-associated Na(+)-dependent inorganic phosphate cotransporter (DNPI; Aihara et al. [2000] J Neurochem 74:2622-2625). In the present study, we produced a specific antibody against a C-terminal portion of DNPI, and studied the immunohistochemical localization of DNPI in the rat cerebral cortex in comparison with that of VGluT1. DNPI immunoreactivity was enriched in neuropil of layers I and IV and to a lesser extent in the upper portion of layer VI of the cerebral neocortex, whereas VGluT1 immunoreactivity was distributed more evenly in neuropil of the neocortex. Electron microscopic observation revealed that both DNPI and VGluT1 immunoreactivities were mainly located on synaptic vesicles in nerve terminals which made asymmetrical contacts in the neocortex. Furthermore, neither DNPI nor VGluT1 immunoreactivity in the neocortex was colocalized with gamma aminobutyric acid (GABA)ergic axon terminal markers, immunoreactivity for glutamic acid decarboxylase or vesicular GABA transporter. Neuronal depletion in the ventrobasal thalamic nuclei produced by the kainic acid injection resulted in a clear reduction of DNPI immunoreactivity in layers I, IV, and VI of the somatosensory cortex. These results indicate that DNPI is located on the membrane of synaptic vesicles in thalamocortical axon terminals, and that it may be a candidate for VGluT of thalamocortical glutamatergic neurons.