Dose- and route-dependent alteration of metabolism and toxicity of chloroform in fed and fasting rats

Effects of overnight food deprivation on the metabolism and toxicity of chloroform (CHCl3) administered to rats per os (po), intraperitoneally (ip), or by inhalation (inh) at different doses were investigated. Rats that had been either deprived of food overnight or normally fed were challenged with CHCl3 either po (0, 100, 200, or 400 mg/kg), ip (0, 100, 200, or 400 mg/kg), or inh (0, 50, 100, or 500 ppm for 6 hr). Overnight fasting increased CHCl3 metabolism in vitro about threefold with a decrease of liver glutathione content to 67%. The fasting caused route- and dose-dependent alteration in the metabolism and toxicity of CHCl3. The area-under-the-curve (AUC) of blood CHCl3 concentration was invariably smaller following po than ip administration, and CHCl3 administered po caused more severe hepatic damage than did the same amount of CHCl3 administered ip. With po administration, the AUC (toxicity) of CHCl3 in fasting rats was significantly smaller (higher) than that of fed rats at a dose as small as 100 mg/kg, whereas, with ip administration at such a small dose, fasting caused no significant alteration in the AUC (toxicity). When rats were exposed by inhalation to CHCl3 vapor, food deprivation had little or no effect on either the blood concentration or the toxicity until the exposure concentration was raised to 500 ppm. The present study indicates that po administration is different from both ip and inh administration with regard to the effect of enzyme induction on the toxicokinetics of CHCl3, mainly due to the first-pass metabolism unique to po administration.

Presynaptic localization of mu-opioid receptor-like immunoreactivity in retinal axon terminals within the terminal nuclei of the accessory optic tract: a light and electron microscope study in the rat

Neuropil within the terminal nuclei of the accessory optic tract of the rat showed intense to moderate mu-opioid receptor-like immunoreactivity (MOR-LI). After unilateral enucleation, MOR-LI within the terminal nuclei almost disappeared or was markedly reduced on the side contralateral to the operation. Electron microscopy revealed that MOR-LI axon terminals within the terminal nuclei were filled with round synaptic vesicles and in asymmetric synaptic contact mainly with dendritic profiles, and occasionally with somatic profiles.

[Leukoencephalopathy in a patient being treated for small cell lung cancer]

A 62-year-old man was given a diagnosis of small cell lung cancer, and received 6 courses of combination chemotherapy (PE therapy) composed of cisplatin (80 mg/m2, day 1) and etoposide (100 mg/m2, days 1, 2, 3). Multiple brain metastases were found, and whole brain irradiation (44 Gy) was given. Eleven months after radiotherapy, he suffered from dizziness and abnormal gait. Enhanced CT of the head showed slight enlargement of the lateral ventricles and markedly low density of the white matter, but no evidence of intracranial tumor involvement. A magnetic resonance scan (axial T2-weighted) showed symmetric extensive hyperintensity in the white matter. Treatment-related leukoencephalopathy caused by the PE therapy and whole brain irradiation was diagnosed. He was alive 8 months after the appearance of neurological symptoms, without recurrence of lung cancer. A search of the literature revealed no previous report of leukoencephalopathy related to PE therapy.

[Anomalous origin of the right pulmonary artery from the ascending aorta: a case report]

We report a successful case of anomalous origin of the right pulmonary artery from the ascending aorta. A 34 days old infant, who had suffered from cardiogenic shock, underwent a direct anastomosis of the right pulmonary artery to the main pulmonary artery behind the ascending aorta under cardiopulmonary bypass. Postoperative catheterization showed no significant stenosis over the anastomosis and normalized pulmonary artery pressure. We conclude that early surgical correction is necessary in the treatment of this life threatening disease.

Nasal natural killer (NK) cell lymphoma: report of a case with activated NK cells containing Epstein-Barr virus and expressing CD21 antigen, and comparative studies of their phenotype and cytotoxicity with normal NK cells

Malignant lymphomas arising from the nasal cavity have been considered to be derived from T cells, but recent surface marker studies suggest that more than half of the lymphomas are derived from natural killer (NK) cells. Here we describe a case of nasal lymphoma whose lymphoma cells were identified as NK cells by morphological, phenotypic, immunogenotypic, and functional studies. We believe this is the first study with functional evidence of NK activity. When compared with normal freshly isolated NK cells or activated NK cells, the surface phenotypes and NK activity of the patient tumour cells were those of the activated, but not resting, NK cells. Also, Epstein-Barr virus (EBV) was detected in the tumour cells and the lymphoma cells were found to be monoclonally expanded. The patient's lymphoma cells also expressed EBV receptor CD21 (CR2) and CD30 (Ki-1) that have not been described on normal NK cells. We therefore examined highly enriched NK cells of normal donors, and found that some resting and/or activated NK cells express these antigens.

The new oral hypoglycemic agent, CS-045, inhibits the lipid peroxidation of human plasma low density lipoprotein in vitro

Several lines of evidence have revealed that the oxidative modification of low-density lipoprotein (LDL) is probably associated with the genesis of the atherosclerotic region. CS-045 is a new (thiazolidine) class of oral hypoglycemic agent which has a hindered phenol in the side chain (an analogue of alpha-tocopherol). The present results indicate that CS-045 had a relatively high antioxidative potency in inhibiting the lipid peroxidation of human plasma LDL in vitro induced by 2,2'-azobis(2-amidinopropane) dihydrochloride (AAPH) compared with that of alpha-tocopherol. These findings suggest that CS-045 may be useful in preventing the progression of atherosclerosis in diabetic patients.

Co-localization of mu-opioid receptor-like and substance P-like immunoreactivities in axon terminals within the superficial layers of the medullary and spinal dorsal horns of the rat

The presence of mu-opioid receptor-like immunoreactivity (MOR-LI) on axon terminals was confirmed by light and electron microscopy within the superficial layers of the medullary and spinal dorsal horns of the rat. By means of double-immunofluorescence histochemistry, co-localization of MOR-LI and substance P (SP)-LI was occasionally observed in axon terminals within the superficial layers of the dorsal horns.

Characterization of the binding sites for [3H]glibenclamide in rat liver membranes

The specific binding sites for sulfonylureas in the rat liver membrane fraction were demonstrated and characterized. [3H]Glibenclamide binding to the liver membrane was specific, time- and temperature-dependent, and reversible. Scatchard analysis showed a single class binding site. The dissociation constant (Kd) for glibenclamide was 1.1 microM and the binding capacity (Bmax) was 50 pmol/mg protein. [3H]Glibenclamide binding could be displaced by other sulfonylureas. Half-maximal inhibition of binding (IC50) for glimepiride, gliclazide, acetohexamide, tolbutamide and chlorpropamide was 4.2 microM, 74 microM, 0.33 mM, 0.60 mM, 1.2 mM, respectively. Each value is close to the reported blood concentration when a therapeutic dose of each drug is administered orally. The order of IC50 values is coincident with the order of potency of the clinical hypoglycemic effect of these drugs. We had shown that these concentrations of sulfonylureas stimulate 6-phosphofructo-2-kinase in the liver or hepatocytes and inhibit phosphoenolpyruvate carboxykinase in the hepatoma cells. The specific binding sites demonstrated here may play some roles when sulfonylureas affect carbohydrate metabolism in the liver.

Intraportal endovascular ultrasonography as a new diagnostic procedure in pancreatic surgery

BACKGROUND/AIMS

This presents the results of a prospective study on the use of intraportal endovascular ultrasonography (IPEUS) as a screening tool for pancreatic carcinoma.

PATIENTS AND METHODS

Twenty-four patients with pancreatic cancer (17 head, 7 body) were studied for portal vein invasion using intraportal endovascular ultrasonography (IPEUS). In 22 cases, IPEUS was performed intraoperatively from the superior mesenteric venous route with an 8-French, 20 MHz intravascular ultrasound (IVUS) catheter, in two cases preoperatively from the percutaneous transhepatic route with a 6- French, 20 MHz IVUS catheter. The sonographic criterion for detection of portal venous invasion was obliteration of the echogenic band of the portal vein. The IPEUS results were compared with those of CT and portography.

RESULTS

Vascular invasion was confirmed with resected specimens in nine cases and with operative findings in three patients. For diagnosis of portal venous invasion, the sensitivity, specificity, and overall accuracy of IPEUS were 100%, 91.7%, and 95.8% respectively. For portography, the equivalent values were 66.7%, 75%, and 70.8%, while those for CT were 75%, 66.7%, and 70.8%.

Regional vascular resection using catheter bypass procedure for pancreatic cancer

BACKGROUND/AIMS

To elucidate the indications for extended operation including main vessel resection in pancreatic cancer surgery, a clinical study was performed. The safety and clinical significance of portal vein resection in pancreatic cancer surgery have not yet been obtained in a large series.

MATERIALS AND METHODS

Over a period of more than 10 years, 134 of 212 (63%) patients with pancreatic carcinoma underwent resection by extensive radical surgery. Portal vein resection was performed in 104 of 134 (78%) resected cases using catheter bypass procedure. The postoperative survival was investigated and a clinicopathological study was conducted.

RESULTS

Operative death within 30 days after operation was observed in 11 of 134 (8%) resected cases. Postoperative survival rate correlated with the grade of portal vein invasion, which was diagnosed by preoperative or intraoperative portography. Survival for more than two years after operation was seen in cases of negative invasion on the margins of the resected specimens group even when portal system vein wall invasion was observed.

CONCLUSION

Portal vein resection is performed safely using bypass procedure of the portal vein and is recommended to obtain a tumor-free surgical margin.

Sequence analysis of the genome of the unicellular cyanobacterium Synechocystis sp. strain PCC6803. I. Sequence features in the 1 Mb region from map positions 64% to 92% of the genome

The contiguous sequence of 1,003,450 bp spanning map positions 64% to 92% of the genome of Synechocystis sp. strain PCC6803 has been deduced. Computer analysis of the sequence predicts that this region contains at least 818 potential ORFs, in which 255 (31%) were either genes that had already been identified or their homologues, 84 (10%) were homologues to registered hypothetical genes, and 149 (18%) showed weak similarities to reported genes. The remaining 330 ORFs showed no apparent similarity to any reported genes or carried no significant protein motifs. The potential ORFs as a whole occupied 86% of the sequenced region, implying compact arrangement of genes in the genome. As to the structural RNA genes, one rRNA operon consisting of 5,028 bp and at least 11 species of tRNA genes were identified. It is noteworthy that 10 out of the 11 tRNA species showed significant sequence similarities to tRNAs reported in plant chloroplasts. As other notable unique sequences, three classes of IS-like elements each with characteristics typical of IS elements were identified, and a typical unit of WD(Trp-Asp)-repeats which have only been detected in the regulatory proteins of eukaryotes was identified within the large 5,079-bp ORF located at map position 69%.

Extrapancreatic effects of sulfonylurea drugs

Extrapancreatic action of sulfonylurea (SU) drugs were extensively summarized. Hypoglycemic SU drugs stimulate glycolytic pathway and inhibit gluconeogenic pathway in the liver through regulating key enzymes such as the bifunctional enzyme PFK2/F-2,6-P2ase and PEPCK. It is possible that SUs improve the primary defects in NIDDM through both pancreatic and extrapancreatic actions.

Glycosphingolipids in human pancreatic juice. Unique fatty acid compositions of glucosylceramides and lactosylceramides

Glycosphingolipids in human pancreatic juice were isolated and purified by DEAE and silica gel column chromatographs, and further by HPLC on silica gel and reversed-phase columns. The structures of the glycosphingolipids were determined to be glycosylceramides and lactosylceramides by means of fast atom bombardment mass spectrometry, 1H-NMR spectroscopy, and component analysis involving GLC-mass spectrometry. The ceramide portions of the glucosylceramides consist of palmitic, tetracosanoic, and alpha-hydroxy tetracosanoic fatty acids, and d18:1 and t18:0 sphingosines. The ceramide portions of the lactosylceramides consist of palmitic, teracosanoic, tetracosenoic, and tetracosadienoic fatty acids, and d18:1 sphingosine. The fatty acid compositions are different from the free fatty acid compositions of serum and pancreatic juice. The predominance of saturated, unsaturated, and hydroxy tetracosanoic fatty acid is quite unique, and the possibility that these glycosphingolipids may play a specific role in pancreatic juice deserves consideration. These glycosphingolipids were documented to be major components of the pancreatic juice from 15 patients with a variety of pancreatic diseases.

A t(11;14)(p13;q11) specific for T-cell malignancies in acute megakaryoblastic leukemia

A 2-year-old girl with a very rare form of acute megakaryoblastic leukemia (AMKL), having the 11p13;14q11 translocation specific for T-cell malignancies, is reported. She was diagnosed as having AMKL on the basis of her bone marrow, which contained 30% megakaryoblasts identified by characteristic morphology on May-Giemsa stain, positive for platelet peroxidase activity and for the surface marker of platelet glycoprotein IIb/IIIa, CD41. Cytogenetic studies of marrow cells revealed 47,XX,i(7q), +der(11)t(11;14)(p13;q11), -14, +21. She achieved hematologic remission after two courses of chemotherapy including behenoyl cytarabine, acracinorubicin, 6 mercaptopurine, and prednisolone, but soon relapsed and died 11 months after admission. This case suggests that adequate diagnostic assessments of morphology, surface markers, and cytogenetics are necessary for proper diagnosis in leukemia and lymphoma, and that an important, though as-yet unidentified, gene in megakaryopoiesis may reside in the 14q11 chromosomal region.

HepG2/erythrocyte glucose transporter (GLUT1) gene in NIDDM: a population association study and molecular scanning in Japanese subjects

To evaluate the role of mutations in the glucose transporter (GLUT1) gene in Japanese patients with non-insulin-dependent diabetes mellitus (NIDDM), we first conducted a population association study using the XbaI polymorphism of the gene. A polymerase chain reaction (PCR)-based assay was developed and used for the analysis. When analysed in 91 diabetic patients and 87 non-diabetic control subjects, the distribution of the genotype frequency was significantly different between the two groups (p = 0.0025). The (-) allele was significantly associated with NIDDM (odds ratio 2.317, 95% confidence interval 1.425-3.768). To identify possible mutation(s) in the GLUT1 gene, which was in linkage disequilibrium with the (-) allele, all ten exons of the gene were analysed by PCR single-strand conformation polymorphism (SSCP) analysis in 53 diabetic patients with at least one (-) allele. Variant SSCP patterns were detected in exons 2, 4, 5, 7, 9 and 10. Sequence analysis revealed that all the variants represented silent mutations. One of the variants in exon 2, GCT (Ala15)-->GCC(Ala), created a HaeIII restriction site. This polymorphism was common in Japanese subjects with heterozygosity of 0.36 and polymorphism information content 0.29. We conclude that the structural mutation of GLUT1 is rare and not likely to be a major genetic determinant of NIDDM in Japanese subjects. The XbaI (-) allele of the GLUT1 gene appeared to be a genetic marker of NIDDM in Japanese subjects. The possibility of the presence of mutation(s) in the regulatory region of the gene or in another locus nearby could not be excluded.

Immune response to hepatitis C virus core protein in mice

To analyse the immune response to the hepatitis C virus (HCV) core protein, we immunized mice with the protein. BALB/c (H-2d) and C3H/He (H-2k) mice were high responders, while C57BL/6 (H-2b) mice were low responders in terms of Th cell proliferative responses. All the strains showed comparable levels of antibody responses to the HCV core protein. The Th cell lines recognized residues 61-90 of the HCV core protein in the context of I-Ad (BALB/c) and residues 11-30 in the context of I-Ek (C3H/He), respectively. The Th cell lines were restricted by I-Ab in C57BL/6 mice but recognized no synthetic peptide that spanned the region, although derivative clones from the line recognized residues 1-20 and 91-110 of the HCV core protein, respectively. The Th cell lines were Th 1 subset in all three strains based on the profile of lymphokine secretion. The major B cell epitope of the protein was found to be within residues 21-40 of the HCV core protein in all three strains. These observations should be useful for better understanding of the immune response to the HCV core protein in vivo.

Differential diagnosis of pulsatile neck masses by Doppler color flow imaging

A pulsatile neck mass (PNM) requires careful judgment in its evaluation, and it is difficult and inaccurate to diagnose a PNM only by physical examination, even though a thrill or bruit is present. Doppler colorflow imaging (DCI) was performed as an initial evaluation in nine patients with PNMs. Intravenous digital subtraction angiography, intra-arterial angiography, X-ray computed tomography, and magnetic resonance imaging were performed in selected cases. The DCI revealed seven vascular masses (three tortuosities of the common carotid artery, two tortuosities of the brachiocephalic artery, one pseudoaneurysm, and one traumatic arteriovenous fistula) and two nonvascular masses (one neurofibroma and one metastatic lymph node). The clinical diagnoses of all the vascular masses were defined by DCI. In nonvascular masses, fine-needle aspiration biopsy could be performed relatively safely and accurately by monitoring the feeding artery or the common carotid artery by DCI. This method was quite useful for the initial evaluation in the differential diagnosis of PNMs.

Effects of long-term treatment with recombinant human granulocyte-macrophage colony-stimulating factor in patients with myelodysplastic syndrome

We examined the effects of long-term treatment with recombinant human granulocyte-macrophage colony-stimulating factor (rhGM-CSF) in 61 patients with myelodysplastic syndrome (MDS). Patients were randomly assigned to receive daily subcutaneous injection of 60 micrograms/m2, 125 micrograms/m2 or 250 micrograms/m2 for 8 weeks. A significant increase in granulocyte counts including neutrophils and eosinophils was shown from one week after the start of the treatment in all three dose groups. The increase in granulocyte counts reached a plateau at the 4th week and was sustained during the treatment period. However, no consistent change in other cell lineages including monocytes, lymphocytes, reticulocytes and platelets were observed. Nevertheless peak-levels of these cells were significantly higher than the pre-treatment levels. In higher dose groups, the number of patients developing infections was reduced. There was no significant difference in the incidence of adverse events among the 3 dose groups, and the toxicity was generally well-tolerated. These observations indicate that treatment with rhGM-CSF can be of potential therapeutic benefit to patients with MDS.

Relevance of oxidative stress to the limited replicative capacity of cultured human diploid cells: the limit of cumulative population doublings increases under low concentrations of oxygen and decreases in response to aminotriazole

Human diploid cells, TIG-7, were serially cultivated under 1%, 5% or 21% (air) oxygen. The limit of their cumulative population doublings was extended by 16% or 10% under 1% or 5% oxygen, respectively, as compared with that under 21% oxygen. When TIG-7 cells were serially cultivated in the presence of 10 mM or 20 mM 3-amino-1H-1,2,4-triazole, an inhibitor of catalase scavenging hydrogen peroxide, the limit of their cumulative population doublings was shortened by 4.4% or 14.4%, respectively, as compared with untreated cells. In addition, long-term, rather than short-term, exposure of TIG-7 cells to aminotriazole retarded cell growth. Treatment with aminotriazole caused decreases not only in catalase activity but also in superoxide dismutase activity and reduced glutathione concentration, and an increase in glutathione peroxidase activity. These results suggest that the limit of the cumulative population doublings of human diploid cells is extended or shortened under decreasing or increasing oxidative stress, respectively. Oxidative stress may be relevant to replicative capacity, and a causative factor for oxidative stress may be hydrogen peroxide.

Phosphorylation of hepatitis C virus-encoded nonstructural protein NS5A

Two proteins, a 56-kDa protein (p56) and a 58-kDa protein (p58), are produced from the hepatitis C virus (HCV) nonstructural region 5A (NS5A). Recently, we found that both proteins are phosphorylated at serine residues and that p58 is a hyperphosphorylated form of p56. Furthermore, hyper-phosphorylation depends on the production of an intact form of the HCV NS4A protein. To clarify the nature of NS5A phosphorylation, pulse-chase analysis was performed with a transient protein production system in cultured cells. The study indicated that basal and hyperphosphorylation of NS5A occurred after proteolytic production of NS5A was complete. In an attempt to identify the location of the hyperphosphorylation sites in p58, proteins with sequential deletions from the C-terminal region of NS5A and with mutations of possible phosphorylated serine residues to a neutral amino acid, alanine, were constructed. The deleted or mutated proteins were then tested for hyperphosphorylation in the presence of the NS4A product. Here, we report that serine residues 2197, 2201, and/or 2204 are important for hyper-phosphorylation. Important sites for basal phosphorylation were identified in the region from residues 2200 to 2250 and in the C-terminal region of the NS5A product. A subcellular localization study showed that most of the NS5A products were localized in the nuclear periplasmic membrane fraction.

Digestibility characteristics of isomaltooligosaccharides in comparison with several saccharides using the rat jejunum loop method

Isomaltooligosaccharides (IMO) are a mixture of isomaltose, isomaltotriose, panose, isomaltotetraose, etc. IMO and its hydrogenated derivative (IMH) were characterized for their luminal clearance from rat jujunum loops as the indication of their digestibility. They were compared with a disaccharide fraction (IM2) and a higher oligosaccharide fraction (IM3) prepared from IMO, typical digestible saccharides (maltose, maltotriose, and sucrose), and typical nondigestible saccharides (maltitol, raffinose, and fructooligosaccharides (FO)). The clearance rate of IMO was significantly smaller than that of IM2, which was mainly composed of isomaltose (64.3%), and digestible saccharides, and significantly larger than that of nondigestible saccharides. That of IM2 was almost the same as that of sucrose or maltotriose but significantly smaller than that of maltose. That of IM3 tended to be smaller than that of IMO, and larger than that of nondigestible saccharides. That of IMH was significantly smaller than that of IMO and similar to that of maltitol. These results seem to indicate that IMO is slowly digested in the jejunum, that the components having higher degree of polymerization of IMO are less digestible, and that IMH is nondigestible.

Effects of ajmaline on non-sodium ionic currents in guinea pig ventricular myocytes

The lack of currently available data stimulated us to investigate the electrophysiological effects of ajmaline, a classical class Ia antiarrhythmic agent, on various currents responsible for the action potential plateau and repolarization phases. The whole cell patch clamp recording technique was applied to guinea pig ventricular myocytes. Ajmaline suppressed the Ca2+ current (Ica) in a dose-dependent manner (Kd = 1.2 x 10(-5) M) without affecting the steady-state inactivation kinetics and the voltage dependency of the current-voltage relationship. Ajmaline inhibited the inward portion of the inward rectifying K+ current (IKl). Ajmaline decreased the delayed rectifier K+ current (IK) without altering the activation or deactivation time courses. All these inhibitory effects of ajmaline prolonged the action potential duration in a dose dependent manner. The inhibitory actions of ajmaline on the action potential upstroke and various currents responsible for the plateau and repolarization may contribute to the observed suppression of depolarization-induced abnormal automaticities by this agent.

Elevated intracellular cyclic AMP inhibits chemotaxis in human eosinophils

Elevated intracellular cyclic AMP is associated with the inhibition of many inflammatory cellular responses. In this study, we examined the effect of cyclic AMP on eosinophil chemotaxis. Eosinophils were isolated from healthy human volunteers using an immunomagnetic method. Eosinophils were treated with agents that elevate intracellular cyclic AMP and evaluated for chemotactic responses to platelet-activating factor (PAF; 10(-6) M) and to complement factor 5a (C5a; 10(-8) M) in microchemotaxis chambers. Forskolin, prostaglandin E1 (PGE1), and a phosphodiesterase (PDE) IV-selective inhibitor inhibited eosinophil chemotactic responses. The mean per cent inhibition of eosinophil chemotaxis in response to PAF by forskolin, PGE1, and the PDE IV-selective inhibitor (10(-5) M) was 16.8 +/- 5.3, 26.6 +/- 9.5, and 35.1 +/- 6.1%, respectively (n = 5). The corresponding values for C5a were 17.5 +/- 7.9, 20.8 +/- 10.7, and 39.5 +/- 5.0%. An exogenous cyclic AMP analogue (dibutyryl cyclic AMP, 10(-3) M) also inhibited eosinophil chemotaxis by 69.4 +/- 12.8 and 66.9 +/- 11.6% in response to PAF and C5a, respectively (n = 5). We conclude that elevated intracellular cyclic AMP inhibits eosinophil chemotaxis.