p-Dichlorobenzene-induced hepatotoxicity in mice depleted of glutathione by treatment with buthionine sulfoximine

p-Dichlorobenzene (p-DCB) is widely used as a moth repellent and a space deodorant. In mice pretreated with DL-buthionine sulfoximine (BSO; 2 mmol/kg or higher doses, i.p.), an inhibitor of glutathione (GSH) synthesis, administration of p-DCB (100-400 mg/kg, p.o.) resulted in dose-dependent hepatotoxicity as judged by increased serum alanine aminotransferase (ALT) activities and liver calcium concentrations and by histological examination of the liver, p-DCB alone (up to 1200 mg/kg) resulted in no hepatotoxicity. Administration of GSH monoethyl ester, which is known as a useful means for increasing organ GSH levels, protected against the hepatotoxicity caused by p-DCB in combination with BSO. Treatment with inhibitors of hepatic cytochrome P-450-dependent monooxygenases, carbon disulfide, metyrapone and piperonyl butoxide also prevented the hepatotoxicity. These results suggest that p-DCB is activated by a cytochrome P-450-dependent metabolic reaction and that the hepatotoxicity is caused by inadequate rates of detoxification of the resulting metabolite in mice depleted of hepatic GSH by BSO treatment. The liver injury was preceded by an extensive depletion of hepatic GSH but not accompanied by significant changes in hepatic contents of lipid peroxides and protein thiols.

Application of DNA fingerprinting in the Hokkaido brown bear (Ursus arctos yesoensis)

DNA fingerprinting employing a minisatellite Myo probe was used for individual identification and paternity determination in Hokkaido brown bears (Ursus arctos yesoensis). We used two restriction enzymes, HinfI and HaeIII to make DNA fingerprints. Band patterns obtained from randomly selected bears were compared with each other, and the probability x that fragment in an individual was also present in the other was 0.69 for HinfI and 0.83 for HaeIII. The value for HinfI (0.69) was similar to that obtained from other species, such as dog and domestic animals, and the mean probability of all fragments was calculated to be 2.5 x 10(-2). The results suggest that DNA fingerprinting applying the combination of HinfI and Myo is available for individual identification. On the other hand, the ability to determine paternity seemed to be insufficient owing to the lack of paternal fragments, although the band patterns reflected the correct relationships between child and father.

In vivo and in vitro transcription of small mRNAs containing a leader sequence from mouse hepatitis virus strain JHM

Two additional small RNAs, named mRNA8 and 9, are transcribed from mouse hepatitis virus (MHV) in virus-infected mouse DBT cells. This report shows that the small mRNAs (mRNA8 and 9) were observed at 3 hr post infection (p.i.) in DBT cells infected with the JHM strain of MHV. This result suggested that products from mRNA8 and 9 may play a role in the early stage of the viral replication cycle in the infected DBT cells. The mRNA8 is initiated from a perfectly conserved intergenic site, but mRNA9 is from an imperfectly conserved intergenic sequence. Since mRNA8 and 9 were found in the liver and brain of an infected mouse, it was suggested that the imperfect intergenic sequence of MHV may serve as an initiation site for leader-primed transcription in vivo.

Inhibition of viral multiplication by hammerhead ribozymes targeted against the polymerase gene of mouse hepatitis virus

We designed and constructed two hammerhead ribozymes targeted against the polymerase gene of mouse hepatitis virus (MHV). They consisted of a 22-nucleotide (nt) ribozyme core sequence and antisense sequences of different lengths, 243-nt (S-ribozyme) and 926-nt (L-ribozyme). In cell-free reactions, the constructed ribozymes cleaved the target RNA at a specific site. Vectors that directed the expression of ribozymes by a promoter of human elongation factor 1 alpha were introduced into DBT cells, and the resulting several cell lines constitutively expressing the ribozymes were selected by Northern blot analysis and examined for intracellular multiplication of MHV. The production of infectious progeny virus particles was significantly reduced in the transfected cell lines expressing either S-ribozyme or L-ribozyme. Although the in vitro cleavage process of L-ribozyme was slower than that of S-ribozyme, no difference was observed in inhibitory effects on MHV multiplication between S- and L-ribozymes in the transfected cells.

A high alpha-linolenate diet suppresses antigen-induced immunoglobulin E response and anaphylactic shock in mice

Mice were fed for 2 mo diets having ratios of alpha-linolenate [18:3 (n-3)] to linoleate [18:2(n-6)] of < 0.01, 0.36, 1.0 and 3.9. Proportions of safflower seed oil and perilla seed oil were adjusted to obtain these ratios. The dietary alpha-linolenate to linoleate balance was reflected in the proportion of (n-3) and (n-6) highly unsaturated fatty acids with 20- and 22-carbon chains in spleen phospholipids, but the ratio did not affect the proportion of T lymphocyte subsets expressing CD4 and CD8 antigens in splenic leukocytes. The immunoglobulin (Ig) G and IgM responses against sheep red blood cells when estimated as plaque-forming cells present in spleen, were not affected significantly by the diets. However, the serum hemagglutinin titer was slightly but significantly higher in the high alpha-linolenate diet group [18:3(n-3)/18:2(n-6) = 3.9] than in the dietary group with 18:3(n-3) to 18:2(n-6) ratios of 0.36 and < 0.01. In contrast, the IgE antibody response against egg albumin, as well as the mortality from anaphylactic shock induced by a second challenge with antigen, was significantly lower in the high alpha-linolenate diet group [18:3(n-3)/18:2(n-6) = 3.9] than in the high linoleate diet [18:3(n-3)/18:2(n-6) < 0.01] group. These results, together with the reported suppressive effects of a high alpha-linolenate diet on the formation of lipid-derived allergic mediators, support the hypothesis that raising the (n-3) to (n-6) ratios of diets would be effective in reducing the severity of immediate-type allergic hypersensitivity.

[Evaluation of peritoneal lavage smears and gastric wall brushing smears in gastric cancer surgery]

We investigated the utility of intraoperative peritoneal lavage smears and gastric wall brushing smears for diagnosis of peritoneal dissemination and serosal involvement during gastric cancer surgery. One hundred fifty-three patients with gastric cancer were examined; 138 who underwent gastric resection and 15 who did not. The incidence of cancer cell positivity determined by these methods was 8.0% in resected cases, and 80.0% in unresected cases. According to macroscopic serosal invasion, the incidence of positive cytology was 0% for S0, 15.4% for S1, 13.0% for S2, and 38.7% for S3. According to microscopic wall invasion, the incidence of positivity was 0% for m and sm, 6.3% for mp, 0% for ss, and 22.2% for se and si. In terms of macroscopic peritoneal dissemination, the incidence of positivity was 2.6% for P0, 28.6% for P1, 42.9% for P2, and 90.0% for P3. These results suggest that peritoneal lavage smears and gastric wall brushing smears are useful for predicting the spread of peritoneal dissemination. Thus, further study of intraoperative fast-smear cytology seems warranted.

Formation of toxic metabolites from thiabendazole and other thiazoles in mice. Identification of thioamides as ring cleavage products

The metabolism of three nephro- or hepatotoxic thiazoles--2-(thiazol-4-yl)benzimidazole (thiabendazole) (1a), 4-tert-butyl-2-methyl-thiazole (1b), and 2-(p-methoxyphenyl)-4-methylthiazole (1c)--was examined in mice with special regard to the formation of ring cleavage products. By GC/MS analyses of derivatized metabolites and comparison with authentic samples, thioformamide and benzimidazol-2-ylglyoxal as the accompanying fragment were identified as urinary metabolites in mice dosed with 1a. Similarly, 1b produced thioacetamide and tert-butylglyoxal, and 1c produced p-methoxy-thiobenzamide (and its S-oxide) and methylglyoxal. These results could be explained by the postulated metabolic pathways where thiazoles would undergo microsomal epoxidation of the C = C double bond and, after being hydrolyzed, the resulting epoxide would then be decomposed to form the corresponding thioamides and alpha-dicarbonyl fragments.

[Treatment for peritoneal dissemination of gastric cancer by intraperitoneal administration of CDDP through Infuse-a-Port]

This report describes the effect of intraperitoneal administration of CDDP for the treatment of peritoneal dissemination (P) in 20 patients with gastric cancer. Eight patients after palliative resection, 4 after non-resection and 8 with recurrent cancer were given 25 mg of CDDP through a reservoir (Infuse-A-Port) implanted in the abdominal wall once a week. Simultaneously, 400 mg/body/day of UFT and 2 mg/body/week of Lentinan were administered. Twelve of the patients died of disease at 6-19 months (median 7 months), but 8 have survived 3 to 15 months (median 6 months). Complete and partial responses were obtained in 7 of the 8 patients with recurrence (88%) for malignant ascites. No patient showed any toxicity from treatment. All patients receive the treatment in the outpatient clinic after discharge, and 17 patients have shown a long hospital-free survival.

The presence of tumor necrosis factor-alpha and its antibody in the sera of cachexic patients with gastrointestinal cancer

Although cancer cachexia has been shown to involve several cytokines, the tumor necrosis factor-alpha (TNF) has rarely been detected in such patients. In this study, sera from 21 patients with cancer cachexia were examined for the presence of TNF and the anti-TNF antibody using an enzyme-linked immunosorbent assay (ELISA) and Western blotting, respectively. All of the patients had recurrent cancer and manifested the characteristics of progressive body weight loss. TNF was found in the sera of four patients (20%) at levels ranging from 10.4 to 53.1 pg/ml, while a positive reaction for the anti-TNF antibody was detected in the sera from six patients (30%), two of whom showed both TNF and its antibody. Thus, either TNF or the anti-TNF antibody was present in the sera from 8 of 21 patients (40%). The results of this study indicate that TNF may be present in the circulation of at least 40% of cachexic patients, and suggest that it may be one of the main mediators of cancer-associated cachexia.

The inhibitory effects of MgSO4 on the multiplication and transcription of mouse hepatitis virus

The multiplication of mouse hepatitis virus (MHV) was inhibited by the treatment of infected cells with MgSO4 at concentrations higher than 50 mM. The inhibition of viral multiplication was more effective with the treatment of cells at the early stage of infection using MgSO4 than at the late stage. Viral adsorption to the cells was not inhibited by MgSO4 and pretreatment of the cells with MgSO4 did not show an inhibitory effect on the RNA synthesis of MHV. The synthesis of viral RNA was inhibited more effectively by the treatment of infected cells with MgSO4 at 0-2 and 2-4 h postinfection (p.i.) than at 4-6 h p.i. The present study suggests that the stage at which viral multiplication is susceptible to MgSO4 may be the early stage of viral transcription and that Mg2+ may be a useful tool for the analysis of the early stage of MHV infection.

A factor protecting mammalian [75Se]SeCys-tRNA is different from EF-1 alpha

In Escherichia coli, an elongation factor (EF-Tu-like) specific to SeCys-tRNA, SELB, has been identified; however, a mammalian counterpart of SELB has not been reported to date. We searched for and found this factor in bovine liver extracts using the assay of [75Se]SeCys-tRNA protecting activity against alkaline hydrolysis (SePF activity). We found SePF activity in the protein extracts of the precipitate (microsomal fraction) collected at 150,000 x g from bovine liver. The proteins were separated by Sephacryl S-300 chromatography, and the SePF and EF-1 alpha activities were found in the same fraction, indicating that SePF and EF-1 alpha have the same molecular mass (approximately 50 kDa). We then chromatographed this active fraction using CM-Sephadex C-25 columns. The SePF activity was eluted after the peak of EF-1 alpha activity. This result indicated that this SePF activity was not dependent on EF-1 alpha. In addition to performing these two chromatographies, we investigated pure EF-1 alpha from Bombyx mori but could not detect any SePF activity in B. mori EF-1 alpha. Thus we showed that the SePF activity in bovine liver differs from that of EF-1 alpha in eukaryotes. Therefore the factor protecting [75Se]SeCys-tRNA in bovine liver is not EF-1 alpha and must be a SELB-like factor.

[Adult-onset dementia with abundant neurofibrillary tangles resembling progressive supranuclear palsy]

We described an autopsy case of 79-year-old woman with clinically unclassified senile dementia. The patient developed forgetfulness at the age of 73, and later, persecution mania, apathy and episodic stupor, but no extrapyramidal symptoms. Neuropathological examination revealed severe neuronal loss and gliosis of substantia nigra, moderate neuronal loss and marked grumose degeneration of dentate nucleus, and mild astrocytosis of subthalamic nucleus. Abundant neurofibrillary tangles (NFT) were observed in subthalamic nucleus, globus pallidus, substantia nigra, locus ceruleus, tegmentum of brain stem, pontine nucleus, inferior olive, and dentate nucleus. Gallyas silver impregnation method showed a wide distribution of argyrophilic grains and threads in cerebrum, brain stem and cerebellum. Although absence of clinical and neuropathological hallmarks excluded the diagnosis of progressive supranuclear palsy (PSP), the distribution of NFT and argyrophilic grains in this patient resembled PSP.

[Morphometric study of age-related changes of the spinal cord]

The relation of aging to the length of the spinal cord and to the cross-sectional area at the levels of C6 and L3 of the spinal cord was studied in 140 autopsy cases who between the age of 47 to 105 without spinal cord lesions. In addition the effect of being bed-ridden on the spinal cord was studied in 11 of 140 cases. As pathological controls, we referred to 40 autopsy cases with compression change of the cervical cord. The length of the spinal cord had no correlation with aging but had a significant positive correlation with the height of the subject. A significant decrease in the cross-sectional area of the spinal cord was observed after the age of 80, in particular at C6. However, the extent of the decrease was not as serious as that of pathological control cases. Decrease of cross-sectional area was associated with that of white matter area. In addition, effect of being bed-ridden on the spinal cord was reflected in a significant decrease of the grey matter of the lumbar cord.

Identification of estrogen receptor in human adipose tissue and adipocytes

Estrogen has various effects on adipose tissue. Although the presence of estrogen receptor (ER) has been demonstrated in rat adipose tissue and adipocytes, ER has not been identified in human adipose tissue. In this study, we demonstrated the existence of ER protein and ER messenger RNA (mRNA) in human sc adipose tissue and adipocytes. The cytosol fraction of human adipose tissue was partially purified by ammonium sulfate precipitation, and the presence of ER protein was analyzed by [3H]estradiol (E2) binding assay and Western blot analysis. [3H]E2 binding assay showed a low specific binding due to high nonspecific binding, and the dissociation constant (Kd) and maximal binding sites could not be obtained by Scatchard analysis. Western blots, however, showed the presence of ER protein in both the partially purified cytosol and nuclear fractions of human adipose tissue. The mol wt of ER in both fractions was approximately 66,000. Furthermore, Northern blot analysis of total RNA samples isolated from human adipose tissue showed the expression of ER mRNA at 6.2 kilobase in size. ER mRNA was also identified in isolated human adipocytes by the reverse transcription and polymerase chain reaction. These results indicated that both ER protein and ER mRNA are expressed in human adipocytes, suggesting that the effect of estrogen on human adipose tissues might involve a direct action.

Amyloid beta precursor protein and ubiquitin epitopes in human and experimental dystrophic axons. Ultrastructural localization

Dystrophic axons (DA) represent a major pathological feature of several neurodegenerative disorders, including infantile neuroaxonal dystrophy (INAD) and Alzheimer disease. We have previously presented evidence that amyloid beta precursor protein (BPP) and ubiquitin (Ub) are present in DA of different origin. We have now characterized the immunoreactivity of DA experimentally induced in rat by the administration of parabromophenylacetylurea (BPAU) and examined the subcellular localization of Ub and BPP in BPAU-induced DA and in DA present in subjects affected by INAD. BPAU-induced DA strongly immunoreacted with antisera to Ub and to COOH- and NH2-terminal regions of BPP. Immunoblots of DA-enriched brain regions were consistent with an increase in the amount of Ub and BPP in DA. Moreover, BPAU-induced DA immunoreacted with antibodies to PGP 9.5, a neuronal-specific Ub COOH-terminal hydrolase, and to the inducible heat shock protein 70. Antigenic characterization also indicated that the tubulovesicular membranes within DA derived largely from the smooth endoplasmic reticulum rather than from the Golgi system or the synaptic vesicles. Subcellular immunolocalization of Ub and BPP in both INAD- and BPAU-induced DA revealed that Ub and BPP colocalize in granulovesicular material in both conditions. In INAD DA intense Ub immunoreactivity was also detected in nonmembranous electron dense structures that were present only in these DA, probably because of the chronic course of INAD. Although BPP immunostaining may be related to accumulation of BPP-containing membranes in DA, Ub immunostaining is likely to result from activation of the Ub system by the neuron in the attempt to remove excessive and possibly abnormal proteins. A similar pathogenesis can be postulated for DA of Alzheimer disease.

[Two cases of trochlear nerve neurinoma]

Two cases of trochlear nerve neurinoma without Recklinghausen's disease are described. A 60-year-old male had a left-side sensory disturbance and a hemiparesis. Computed tomography (CT) scan and magnetic resonance image (MRI) showed a cystic enhancing mass in the right tentorial incisura. A 57-year-old male had a gait disturbance and a left-side facial numbness. CT scan and MRI showed a solitary enhancing mass in the right tentorial incisura. These tumors were subtotally removed, and the intraoperative diagnosis of two patients was trochlear nerve neurinoma. Unique clinical manifestations of trochlear nerve neurinoma are discussed with a brief review of 11 cases reported in the literature.

Both antisense and sense RNAs against the nucleocapsid protein gene inhibit the multiplication of mouse hepatitis virus

DBT cells and several transfected cell lines which express antisense or sense RNA against the nucleocapsid protein gene of mouse hepatitis virus (MHV) were examined for the yields of MHV. The transfected cells showed 95 and 99% reduction of virus yield at 9 and 12 hr postinfection (p.i.) as compared with untransfected DBT cells. A remarkable decrease in MHV-specific RNA synthesis was observed in both transfected cell lines at 3.5 hr p.i. The result suggested that both antisense and sense RNAs inhibited viral replication at the initial stage of infection.

Acute bilateral cerebellar infarction in the territory of the medial branches of posterior inferior cerebellar arteries

BACKGROUND

We describe the first clinicoradiological report of acute bilateral cerebellar infarction confined to the territory of the medial branches of the posterior inferior cerebellar arteries.

CASE DESCRIPTION

A 65-year-old man with atrial fibrillation and hypertension had sudden onset of vertigo, followed by brief loss of consciousness. Three days later a cranial computed tomographic scan showed acute hydrocephalus and low-density areas in the cerebellar vermis on both sides. On transfer the patient showed mild dysarthria, dysequilibrium with retropulsion, symmetrical bilateral horizontal gaze-evoked nystagmus on lateral gaze, and marked gait ataxia without brain stem signs, followed by marked vertigo that was induced by motion. Cranial magnetic resonance imaging revealed abnormalities consistent with fairly symmetrical bilateral cerebellar hemorrhagic infarction that was confined to the territory of the medial branches of the posterior inferior cerebellar arteries, in addition to minimal high-intensity areas in the pons on T2-weighted images. The patient improved with conservative therapy, including intravenous administration of glycerol.

CONCLUSIONS

We speculate that our patient likely had initial transient occlusion of the right vertebral artery at the origin of the right posterior inferior cerebellar artery, which probably gave rise to the bilateral medial branches of posterior inferior cerebellar arteries. This caused infarction in the territory of the medial branches on both sides without remaining brain stem signs. Such an unusual pattern of cerebellar infarction accompanied by acute hydrocephalus posed a diagnostic challenge at the time of transfer to our care, and correct diagnosis was facilitated by cranial magnetic resonance imaging.

Neuropathology of late cortical cerebellar atrophy in Japan: distribution of cerebellar change on an autopsy case and review of Japanese cases

We report a Japanese autopsy case of late cortical cerebellar atrophy. The patient had showed clinically transient remission during thyrotropin-releasing hormone therapy. Our case suggests that thyrotropin-releasing hormone therapy is worth trying as a treatment of late cortical cerebellar atrophy. Neuropathological examination showed diffuse cerebellar cortical lesions and absence of neuronal loss in the dorsomedial part of the inferior olives. We studied qualitatively the detailed distribution of the cerebellar cortical lesions in 6 sections of the right cerebellum. The cerebellar lesions were more conspicuous in the most lateral hemisphere than in the vermis. We also reviewed 7 Japanese autopsy cases of late cortical cerebellar atrophy.

Inhibition of mouse hepatitis virus multiplication by antisense oligonucleotide, antisense RNA, sense RNA and ribozyme

Antisense nucleic acids against specific sequences of mouse hepatitis virus (MHV)-RNAs were tested for their inhibitory effects on viral multiplication in mouse DBT cells. An antisense oligonucleotide containing a sequence complementary to leader RNA was synthesized and shown to induce a significant inhibitory effect on the multiplication of MHV-JHM. A vector which expressed the antisense or sense mRNA7 of MHV was transfected into DBT cells. A decreased multiplication of MHV was observed in both cell lines. The transfected cell line which expressed ribozyme against the 5'-end of the MHV genome was established. The rate of inhibition of MHV-multiplication and the quantity of synthesized virus-specific mRNAs in this transfected cell line were the same for both antisense and sense RNA. These results show that antisense nucleic acids might be eligible for use as antiviral agents against MHV multiplication.

SCF/c-kit receptor-mediated arachidonic acid liberation in rat mast cells. Involvement of PLD activation associated tyrosine phosphorylation

We have previously demonstrated PLD activation via c-kit receptor activation in rat peritoneal mast cells (Koike et al. 1993, J. Immunol. 151,359-366). In this study, the mechanism of arachidonic acid (AA) release in stem cell factor (SCF) stimulation was investigated. Genistein, a protein tyrosine kinase inhibitor, was found to inhibit the AA release in SCF-stimulated cells, whereas pretreatment with vanadate, a protein tyrosine phosphatase inhibitor, enhanced the AA release. Propranolol, an inhibitor of phosphatidate (PA) phosphohydrolase, repressed both AA liberation and 1,2-diacylglycerol (1,2-DG) formation. Short pretreatment with phorbol myristate acetate blunted the SCF-induced AA liberation. These results indicate that 1,2-DG generated via the phospholipase D pathway activated by tyrosine phosphorylation is a principle source for AA released in response to SCF in mast cells.

A new inherited prion disease (PrP-P105L mutation) showing spastic paraparesis

We report the clinicopathological findings of 5 patients with an inherited prion disease with a codon 105 (Pro to Leu) mutation. All of the patients had a spastic gait disturbance and progressive dementia without either cerebellar signs, myoclonus, or periodic synchronous discharges. Autopsy of 3 patients revealed numerous amyloid plaques in the cerebral cortex, especially in the motor cortex and the frontal lobe where neuronal loss and severe gliosis were observed in the absence of spongiform changes. The cerebellum was preserved histologically except for only a few amyloid plaques. The pyramidal tracts in the brainstem and spinal cord showed vacuolated changes and a loss of myelin, but no prion protein accumulations. Thus, the prion protein codon 105 mutation is considered to correspond to a new variant of the Gerstmann-Sträussler syndrome with spastic paraparesis.