Different neural substrates for Kanji and Kana writing: a PET study

To investigate the neural substrate underlying the mechanisms of Kanji and Kana writing, we conducted a PET activation study during mental writing task in eight right-handed normal Japanese subjects. During scans subjects were required to mentally write a Kanji or three Kana letters with their right hand, for each stimulant word presented auditorily. The direct comparisons between Kanji writing and Kana writing revealed that the left posterior inferior temporal gyrus was activated in Kanji writing while the left angular gyrus was activated in Kana writing. In addition, more extensive areas were activated in Kanji writing compared with Kana writing. These results suggest that different respective neural substrates are involved in Kanji and Kana writing respectively.

Differential diagnosis between organic and inorganic mercury poisoning in human cases--the pathologic point of view

Differences in pathology were found between acute and chronic exposure to methylmercury, mercury vapor, and inorganic mercury. Characteristic pathologic changes produced by organic mercury in the brain have previously been described in patients with Minamata disease. The brains of patients who presented with acute onset of symptoms and died within 2-mo showed loss of neurons with reactive proliferation of glial cells, microcavitation, vascular congestion, petechial hemorrhage, and edema in the cerebral cortices, predominantly in the calcarine, pre- and postcentral, and transverse temporal cortices and in the cerebellar cortex. The neuropathologic changes in the patients with acute onset of symptoms who survived for a long period (>10 yr) were also included neuronal loss with reactive proliferation of glial cells in similar anatomic locations. The neuropathologic changes in patients with inorganic mercury poisoning are quite different. Autopsies performed on 3 individuals with fatal cases of acute inorganic mercury poisoning who were exposed to mercury vapor for about 2 wk revealed diffuse organized pneumonia, renal cortical necrosis, disseminated intravascular coagulopathy, and infarctions in the brain and kidneys. In 2 other patients who worked in mercury mines for about 10 yr and who suffered from chronic inorganic poisoning, no specific lesions were demonstrated in the brain. However, the assay and the histochemistry of mercury revealed that inorganic mercury was present in the brain in all 3 groups irrespective of the brain lesions and the duration of clinical signs.

Identification and partial purification of DnaK homologue from extremely halophilic archaebacteria, Halobacterium cutirubrum

The levels of synthesis of six proteins were increased at elevated growth temperature of the extremely halophilic archaebacterium Halobacterium cutirubrum. One of these proteins, with an apparent molecular mass of 97 kDa on sodium dodecylsulfate-polyacrylamide gel electrophoresis (SDS-PAGE), bound to an ATP-agarose column in the presence of 4 M NaCl, but not in the absence of salt, indicating that this protein retained its ATP-binding activity only at high salt concentration. The NH2-terminal sequence of this protein and the internal sequences of the tryptic peptides covering 1/3 of the total number of residues coincided with that deduced from the nucleotide sequence of the dnaK gene isolated from H. cutirubrum. The results strongly suggest that this apparent 97-kDa protein is the gene product of dnaK, although the molecular mass calculated from the nucleotide sequence is only 68,495, much smaller than the value of this protein determined by SDS-PAGE. Ferguson plot analysis indicated that this protein showed anomalous mobility on SDS-PAGE. We have purified DnaK homologue to greater than 90% homogeneity with stepwise elution from an ATP-agarose column.

Decreased expression of transforming growth factor beta receptor type I is associated with poor prognosis in bladder transitional cell carcinoma patients

Transforming growth factor (TGF) beta, a potent growth inhibitor of proliferation in most cells, usually exerts its effects through an interaction with membrane receptors, type I (TbetaR-I) and type II (TbetaR-II). In the present study, the expression of TGF-beta receptors was correlated with tumor grade, pathological stage, and probability of progression and survival in patients with bladder transitional cell carcinoma (TCC). To this end, immunohistochemistry was carried out in specimens obtained from 59 patients who underwent either radical cystectomy or transurethral resection of bladder tumor. Among these patients, 18 (30.5 %) had loss of TbetaR-I expression, whereas 27 (44.0%) had loss of TbetaR-II expression. There was a correlation between the loss of expression of TbetaR-I and TbetaR-II and the tumor grade (P = 0.041 and P = 0.026, respectively). In addition, both pathological and lymph node status also were associated with the loss of TbetaR-I and TbetaR-II expression (P = 0.025 and P = 0.004, respectively). Interestingly though, only the loss of expression of TbetaR-I was associated with an increased probability of tumor progression and a decreased probability of survival (P = 0.0046 and P = 0.0022, respectively). These results suggest that the status of TbetaR-I expression may be a potential prognostic marker in patients with bladder TCC.

Perception and conception: separate memory systems in the medial temporal lobe

The purpose of the present study was to investigate, by using positron emission tomography, whether the functionally different types of information are subserved by different memory systems in human medial temporal lobe structures. Before explicit retrieval tests during scans, subjects studied words in perceptually and conceptually processed manners separately. It was found that different parts of the medial temporal lobe structures were involved in each of the different conditions. These results indicated that perceptually and conceptually processed types of information were subserved by at least two partially segregated memory systems in human medial temporal lobe structures.

Liquid chromatography-fast atom bombardment mass spectrometry for detection and determination of pentazocine in human tissues

A reliable and sensitive method was developed for the detection and determination of pentazocine in human solid tissues using liquid chromatography-dynamic fast atom bombardment (FAB) mass spectrometry, combined with a three-step liquid-liquid extraction procedure. Levallorphan tartrate served as an internal standard. The extract was evaporated to dryness and dissolved in the mobile phase, acetonitrile-10 mM ammonium acetate solution (20:80, pH 4.0) containing 0.5% glycerol as FAB matrix. The eluent was pumped at a flow rate of 25 microl/min and split before introduction to FAB mass spectrometer. Quantitative analysis was carried out by means of monitoring quasi-molecular ions with m/z 286 for pentazocine and m/z 284 for levallorphan. The lower limit of detection of pentazocine in each tissue tested was 1 ng/g with scan mode and 0.1 ng/g with SIM mode. Using this method, the concentrations of pentazocine were determined in the tissues of an autopsied individual to perform toxicological evaluation.

Multiple aortocaval fistulas associated with a ruptured abdominal aneurysm in a patient with Ehlers-Danlos syndrome

Aortocaval fistula (ACF) is a rare complication of spontaneous abdominal aortic aneurysm (AAA) rupture, with an incidence of 2-4%. A unique case of ruptured AAA complicated by multiple aortovenous fistulas involving the inferior vena cava and left internal iliac vein is presented, and is the first published report of a patient with Ehlers-Danlos syndrome undergoing surgical treatment for an ACF.

ProstaglandinE(2) Release, Squalene Monohydroperoxide Production and Cell Toxicity of Skin((2TM)) ZK1301 as a Human Skin Model in the Presence of Haematoporphylin and Ultraviolet-A Irradiation

For the clarification of the mechanism of ultraviolet-A (UVA)-induced cytotoxicity to skin, the prostaglandinE(2) (PGE(2)) release and squalene monohydroperoxide (SQOOH) production in a human skin model (Skin(2TM) ZK1301) in the presence of haematoporphylin (HP) as a photosensitizer were investigated.The PGE(2) release and SQOOH production were significantly increased depending on both the irradiation time of UVA (350-380nm) and the HP concentration. In addition, concentration-dependent inhibitions of cytotoxicity, PGE(2) release and SQOOH production were observed when a UVA sunscreen was applied to the surface of Skin(2TM). These results suggest that the mediator of inflammation and lipid hydroperoxide production induced by UVA-HP photosensitization cause cytotoxicity to skin, and that the test method of UVA-HP photosensitization using the Skin(2TM) ZK1301 model is a useful in vitro model for studying UVA phototoxicity and for UVA sunscreen evaluations.

Delayed postoperative CSF rhinorrhea of intrasellar arachnoid cyst

CSF rhinorrhea due to a transsphenoidal approach usually follows accidental or intentional arachnoid opening. We report a patient with an intrasellar arachnoid cyst, who developed delayed onset of CSF rhinorrhea. A sixty-two-year-old man presented with bitemporal type visual field defect for the last 3 years. With the diagnosis of arachnoid cyst or Rathke's cleft cyst, based on MRI findings of intra-and supra-sellar cyst with CSF intensity, he successfully underwent transsphenoidal surgery without evidence of intra-operative CSF leakage. He developed CSF rhinorrhea one week later. This needed another operation for sellar floor repair. The pathomechanism of this delayed onset is explained as follows. Incomplete or oneway communication of subarachnoid space to cyst cavity, unrecognized during surgery, might cause delayed onset of CSF rhinorrhea. By using MRI, identification of the residual gland, which was compressed posteriorly, is useful for differentiating an arachnoid cyst from other cystic lesions. In highly suspect cases, even without evidence of intra-operative CSF leakage, peri-operative measures to prevent occurrence of postoperative CSF rhinorrhea are required.

The loss of expression of transforming growth factor-beta receptors correlates with the histopathologic tumor grade in bladder transitional cell carcinoma patients

Transforming growth factor-beta (TGF-beta), a pleiotropic growth factor, is a potent inhibitor of cellular proliferation in cells of epithelial origin. Recently, it has been suggested that a loss of sensitivity to TGF-beta through a loss of expression of TGF-beta receptors T beta R-I and T beta R-II--is associated with tumor initiation and progression. Therefore, to investigate the relationship between TGF-beta receptors expression and carcinogenesis of bladder TCC, this study examined the expression of T beta R-I and T beta R-II in 46 bladder TCC patients using immunohistochemistry. Since histopathological grade is a widely accepted marker of prognosis, the results were compared in relation to the three grades of bladder TCC. The results demonstrated that the loss of TGF-beta receptors expression is associated with increasing histopathological grades of bladder TCC. Specifically, both T beta R-I and T beta R-II were readily detected in all 10 normal bladder mucosa specimens. Likewise, all 6 specimens of grade I TCC samples expressed high levels of both TGF-beta receptors. However, among grade II TCC samples, T beta R-I and T beta R-II were detected in 78% and 89%, respectively: among grade III TCC samples, T beta R-I and T beta R-II were detected in 45% and 41%, respectively. These results suggested that loss of sensitivity to TGF-beta may play a role in the progression of TCC from low to high grade disease.

Level of retinoblastoma protein expression correlates with p16 (MTS-1/INK4A/CDKN2) status in bladder cancer

Recent studies have shown that patients whose bladder cancer exhibit overexpression of RB protein as measured by immunohistochemical analysis do equally poorly as those with loss of RB function. We hypothesized that loss of p16 protein function could be related to RB overexpression, since p16 can induce transcriptional downregulation of RB and its loss may lead to aberrant RB regulation. Conversely, loss of RB function has been associated with high p16 protein expression in several other tumor types. In the present study RB negative bladder tumors also exhibited strong nuclear p16 staining while each tumor with strong, homogeneous RB nuclear staining were p16 negative, supporting our hypothesis. To expand on these immunohistochemical studies additional cases were selected in which the status of the p16 encoding gene had been determined at the molecular level. Absent p16 and high RB protein expression was found in the tumors having loss of heterozygosity within 9p21 and a structural change (mutation or deletion) of the remaining p16 encoding gene allele, confirming the staining results. These results strongly support the hypothesis that the RB nuclear overexpression recently associated with poor prognosis in bladder cancer is also associated with loss of p16 function and implies that loss of p16 function could be equally deleterious as RB loss in bladder and likely other cancers.

[A case of pure agraphia with a deficit of drawing]

We examined a drawing ability in a case with pure agraphia. The patient, having lesions in the left middle frontal gyrus and inferior parietal lobule, could not write in both dictation and spontaneous writing tasks, with the ability to copy letters being well spared. Correspondingly, he showed a deficit of spontaneous drawing, with the ability to copy complex figures being well spared. These findings suggest that he could have an impairment of retrieving visual image, not restricted to letter image. Although some previous cases with pure agraphia were attributed to an impairment of retrieving visual letter image, drawing ability which seemed to be related to retrieving visual image had not been investigated. In the present case, disability of both writing and drawing could be attributed to a common mechanism, that was an impairment of retrieving visual image. In addition, the patient did not show a significant difference between the performance on Kana writing and on Kanji writing. But it has been said that an impairment of retrieving visual letter image could be related to a deficit of Kanji writing more than of Kana writing. Then, it could be assumed that the mechanism of Kana writing involved not only the pathway depending on graphical motor pattern but one depending on visual image.

Multiple parapapillary choledochoduodenal fistulas with ampullary carcinoma

Only very rarely do multiple parapapillary choledochoduodenal fistulas occur concurrently with ampullary carcinoma. The following presents just such a case, which occurred in a 51 year-old Japanese female hospitalized for epigastralgia. Gastrointestinal fiberscopy (GIF) showed abnormal swelling of Vater's papilla. She was diagnosed as having ampullary carcinoma and choledochoduodenal fistulas, as determined by hypotonic duodenography (HDG), endoscopic retrograde cholangiopancreatography (ERCP) and from the histopathology of the ampullary mucosal biopsy. Pancreatoduodenectomy was performed. We postulated that the multiple fistulas were formed on the longitudinal fold of Vater's papilla by an ampullary carcinoma, and that the fistulas played a major role in bile drainage. As a result, jaundice was not seen throughout the entire clinical course. We report on the mechanism of fistula formation, with a review of the recent literature.

Characterization of deletion mutations in the carboxy-terminal peptide-binding domain of the Kar2 protein in Saccharomyces cerevisiae

Hsp70 is structurally composed of three domains, an amino-terminal ATPase domain, a proximal 18 kDa peptide-binding domain and a distal 10 kDa carboxy-terminal (C-terminal) domain. To dissect the functional significance of the distal 10 kDa domain, and the boundary region between the proximal and distal C-terminal domains of Kar2p in vivo in Saccharomyces cerevisiae, we constructed a series of plasmids which were truncated or had internal deletion mutations in this region. We found that all these mutations are recessive, and that the distal 10 kDa C-terminal domain, including the HDEL ER-retention sequence, is not essential for cell growth, although the major role of this 10 kDa C-terminal domain is due to the function of the HDEL ER-retention signal. We also found that the Kar2p region (Thr492-Thr512), corresponding to the beta 8-sheet in the peptide-binding domain, which constitutes the bottom plate of the binding pocket in E. coli DnaK, is essential for cell viability, and that the following Kar2p region (Glu513-Lys542), corresponding to alpha-helices A and B of E. coli DnaK, which was proposed to compose the lid of the binding pocket, is critical but not essential for yeast cell growth. This was further supported by the fact that the latter deletion showed a fully reversible ts phenotype in its growth and only a slight inhibitory effect on the secretion of alpha-amylase at non-permissive temperature.

Molecular cloning of the dnaK locus, and purification and characterization of a DnaK protein from Bacillus brevis HPD31

Using part of the dnaK gene from Bacillus subtilis as a probe, a 4. 4-kbp SacI-BglII fragment of chromosomal DNA of Bacillus brevis, a protein-hypersecreting bacterium, was cloned. Nucleotide sequencing revealed 3 open reading frames in the order of grpE-dnaK-dnaJ homologues. We purified DnaK protein to homogeneity from B. brevis HPD31 harboring a multi-copy dnaK expression plasmid. Purified DnaK showed ATPase activity which was synergistically stimulated 14-fold by the addition of glutathione S-transferase-DnaJ and glutathione S-transferase-GrpE fusion proteins. DnaK hydrolyzed not only ATP but also CTP, UTP, and GTP at about 40% of the efficiency of ATP. The specific activity of DnaK-ATPase was 7.25x10-3 unit/mg protein (the turnover number against ATP was 0.47 min-1) under our assay conditions. The DnaK dimers dissociated into monomers on addition of ATP, GTP, CTP, UTP and ATPgammaS, but not ADP or AMP. DnaK formed a stable complex with permanently unfolded carboxymethylated alpha-lactalbumin but not with native alpha-lactalbumin, and this complex was dissociated by addition of ATP/Mg. Formation of this complex was inhibited in the presence of inorganic phosphate.

Expression and purification of cytokine receptor homology domain of human granulocyte-colony stimulating factor receptor in Escherichia coli

In an attempt to generate a stable non-glycosylated cytokine receptor homology (CRH) domain (Tyr97-Ala309) of human granulocyte-colony stimulating factor (G-CSF) receptor, two free cysteines in the CRH domain were converted to serine by site-directed mutagenesis. Taking advantage of the tight regulation for the expression of T7 RNA polymerase, the mutated CRH domain was successfully expressed in Escherichia coli (E. coli) with a pelB signal sequence at its NH2-terminus and with a His tag at its COOH-terminus. The processed and secreted CRH domain after solubilization and in vitro refolding retained G-CSF binding activity, and its yield (approximately 40 micrograms/30 ml culture) was more than 100-fold higher than that of the mouse CRH domain expressed by the MalE fusion system in E. coli.

A family with Liddle's syndrome caused by a new missense mutation in the beta subunit of the epithelial sodium channel

Liddle's syndrome is an autosomal dominant form of salt sensitive hypertension caused by mutations in the beta or gamma subunit of the epithelial sodium channel. Systematic mutagenesis studies revealed that a conserved PPPXY sequence (PY motif) of the C-terminus of the alpha, beta, or gamma subunits might be involved in the regulation of the channel activity. However, only two missense mutations in the PY motif of the beta subunit have been reported to cause Liddle's syndrome. We sequenced the C-termini of the beta and gamma subunits of the epithelial sodium channel in a Japanese family clinically diagnosed as having Liddle's syndrome and found a new missense mutation in the PY motif of the beta subunit, P615S. Expression studies with P615S mutant in Xenopus oocytes resulted in an about 3-fold increase in the amiloride-sensitive sodium current compared to the wild type (p = 0.001). These findings provide further clinical evidence for the hypothesis that a conserved PY motif may be critically important for the regulation of the epithelial sodium channel.

Cerebellar hemorrhage associated with moyamoya disease

A 60-year-old female was admitted with complaints of severe headache, nausea, and vomiting. Computed tomography demonstrated a right cerebellar hematoma, which was surgically removed. Bilateral carotid angiography showed occlusions of the anterior and middle cerebral arteries, and abnormal vascular networks. Vertebral angiography showed a well developed posterior pericallosal artery. Left encephalo-duro-arterio-synangiosis was performed. No cerebral vascular incident has been observed for 32 months.

Effect of preceding in vivo sublethal ischemia on the evoked potentials during secondary in vitro hypoxia evaluated with gerbil hippocampal slices

We investigated the mechanism of 'ischemic tolerance phenomenon' by characterizing the physiological events, modified by preceding sublethal ischemia, during secondary hypoxia. Slices from brains after pretreatment of sublethal forebrain ischemia were subjected to a 70% reduction of PO2 (threshold hypoxia). Although evoked potentials disappeared completely in five of eight slices from sham-operated brain, they were sustained in 28/32 slices from pretreated brains. This study indicates that the maintenance of membrane function might be the mechanism of ischemic tolerance.

Expression of RANTES by normal airway epithelial cells after influenza virus A infection

The chemokine regulated on activation, normal T cells expressed and secreted (RANTES), is a C-C chemokine and a potent chemoattractant for monocytes, T lymphocytes, basophils, and eosinophils. Its expression by human airway epithelium has been demonstrated both in vitro and in vivo. We investigated whether RANTES is expressed by normal human airway epithelial cells after influenza viral infection and examined its bioactivity. Epithelial cells were obtained from bronchial tissue or nasal polyps of patients who had undergone lobectomy for lung cancer or polypectomy for nasal polyps. These cells were cultured by the outgrowth method. Cultured cells were infected with influenza virus A (subtype H3N2) after which the supernatants and the cells were collected 8 to 72 h after infection. RANTES mRNA (messenger RNA) was analyzed by the reverse transcriptase-polymerase chain reaction and Southern blot analysis of its product. Concentrations of RANTES in the supernatants were analyzed by enzyme-linked immunosorbent assay. RANTES protein and mRNA were not detected in the media of uninfected cells. PCR products for RANTES were clearly detected in nasal and bronchial epithelial cells 24 h after infection. Southern blot analysis confirmed that the PCR products were indeed specific for RANTES mRNA. Twenty-four to 72 h after infection, significant levels of RANTES protein were detected in culture media. We also investigated the chemotactic activity of the supernatant of cultured cells. The supernatant of the cells 48 h after infection had potent chemotactic activity for eosinophils, which was attenuated by the addition of anti-RANTES antibodies. These findings suggest that influenza virus infection may induce expression of bioactive RANTES by normal human bronchial and nasal epithelial cells.

Endothelin-1 inhibits endothelin-converting enzyme-1 expression in cultured rat pulmonary endothelial cells

BACKGROUND

The lung expresses large amounts of endothelin-converting enzyme-1 (ECE-1), which catalyzes a step in the biosynthesis of potent vasoactive endothelin-1 (ET-1) from the inactive intermediate big ET-1. Because there has been no report concerning a possible relationship between ET-1 and ECE-1, we investigated the effects of ET-1 on ECE-1 expression in cultured rat pulmonary endothelial cells.

METHODS AND RESULTS

ECE-1 messenger RNA (mRNA) and protein expression in cultured endothelial cells were assayed by Northern and Western blotting, respectively. Incubation with ET-1 for 6 hours caused a significant decrease in ECE-1 mRNA expression. The action of ET-1 on ECE-1 mRNA expression was antagonized by pretreatment with BQ788, a specific ETB receptor antagonist, but not by pretreatment with BQ123, a specific ETA receptor antagonist. The expression of ECE-1 protein was also inhibited at 6 hours after incubation with ET-1. The effects of ET-1 on ECE-1 mRNA and protein expression were shown to be mimicked by ionomycin, a calcium ionophore, but not by 12-O-tetradecanoylphorbol 13-acetate, a protein kinase C activator.

CONCLUSIONS

The present results demonstrate that ET-1 suppressed ECE-1 protein levels by inhibiting ECE-1 mRNA expression through the ETB receptor, suggesting the existence of a feedback action of ET-1 on ECE-1 in pulmonary endothelial cells.

[A case of complete remission of gastric endocrine cell carcinoma with multiple bone metastasis by combination chemotherapy and high-dose chemotherapy with autologous peripheral blood stem cell transplantation]

A 31-year-old man was admitted to our hospital complaining of epigastric discomfort and severe lumbago. An upper gastrointestinal endoscopy revealed several submucosallike tumors. Histologic examination of biopsy specimens confirmed the presence of endocrine cell carcinoma. Gallium scintigraphy and CT revealed multiple bone metastasis. He was treated with 6 cycles of combination chemotherapy consisting of CDDP, etoposide, CPA, EPI and VCR. Both gastric tumors and bone metastasis completely disappeared. After 7 cycles of the chemotherapy, he was treated with HDCT with PBSCT. There was no severe complication. This result suggested that the combination of conventional chemotherapy and HDCT with PBSCT was useful in cancer patients with poor prognoses, such as advanced gastric endocrine cell carcinoma.

Plasma concentrations of antipsychotic drugs in psychiatric inpatients

In current psychiatric therapy, two or more kinds of antipsychotic drugs are usually prescribed in Japan. However, there are few data on the therapeutic plasma concentrations of antipsychotic drugs or on the correlation between the daily dose and the plasma concentration, in cases where several antipsychotic drugs had been prescribed for each patient. We measured the therapeutic plasma concentrations of 9 antipsychotic drugs in 24 psychiatric inpatients during a 6-month period. They were treated with fixed dosages of antipsychotic drugs. Plasma samples were collected early in the morning once a month, and the concentrations of antipsychotic drugs were determined by gas chromatography with nitrogen phosphorus detection, high-performance liquid chromatography (HPLC) with fluorescence detection and HPLC with UV detection. The plasma levels of chlorpromazine, levomepromazine, thioridazine, haloperidol, bromperidol, zotepine, oxypertine, sulpiride and sultopride were 21.8-92.4, 31.7-156, 101-203, 16.4-56.2, 2.72-11.7, 13.6-84.0, 29.9-80.4, 70.1-1,120 and 35.7-2,990 ng/ml, respectively. A linear correlation between the daily dose and the plasma concentration was noted for sultopride, levomepromazine, sulpiride, haloperidol, chlorpromazine and zotepine.