Atrial natriuretic peptide induces the expression of MKP-1, a mitogen-activated protein kinase phosphatase, in glomerular mesangial cells

Atrial natriuretic peptide (ANP) has been shown to inhibit the proliferation of various types of cells including glomerular mesangial cells. The activation of mitogen-activated protein kinase (MAPK) is one of the main signal transduction systems leading to cell proliferation. MAPK is tightly regulated by the activating kinase, MEK, and specific phosphatase MKP-1. Constitutive expression of MKP-1 has been shown to inhibit cell proliferation by suppressing MAPK activity. In order to understand the mechanism of the anti-proliferative effect of ANP, we examined whether ANP could inhibit MAPK by inducing MKP-1 in cultured rat glomerular mesangial cells. ANP increased the expression of MKP-1 mRNA in a dose-dependent (10 nM maximum) and time-dependent, with a peak stimulation at 30 min, manner. Receptor for ANP is a transmembrane guanylyl cyclase. Activation of guanylyl cyclase of ANP receptor by ligand plays an essential role in ANP signal transduction. 8-Bromo-cGMP, a cell permeable analogue of cyclic GMP, and sodium nitroprusside, an activator of soluble guanylyl cyclase, could mimic the effects of ANP and were able to induce the expression of MKP-1 in a similar time course as ANP. The protein expression of MKP-1 was maximally stimulated by ANP at 120 min. Treatment of the cells with ANP for 120 min resulted in an inhibition of phorbol ester-induced activation of MAPK, while the activation of MEK was not affected by ANP. These results indicate that ANP might inhibit the proliferation of mesangial cells by inactivating MAPK through the induction of MKP-1.

Efficient gene transfer into mammalian cells using fusogenic liposome

Fusogenic liposome (FL) based on Sendai virus constitutes a unique system that delivers the content efficiently into animal cells in vitro and in vivo. In this study we characterized unilamellar FL as a gene transfer vector in comparison with cationic lipid (CL)-DNA complex. FL transferred genes efficiently into cultured cells even when incubated for as little as 10 min, while CL-DNA complex required at least 30 min to reach the same level of gene expression. FL was also much less cytotoxic than CL-DNA complex under the conditions that resulted in the same level of gene expression. In addition, FL maintained 70% of the transfection activity even in the presence of 40% fetal calf serum (FCS), while CL-DNA complex almost completely lost their activity in the presence of 5% FCS. Furthermore, we found that FL could introduce and express luciferase gene into mouse ascites tumor cells in vivo, but CL-DNA complex could not even at higher concentrations of DNA. We conclude that unilamellar FL is a unique and efficient nonviral vector for gene transfer in vitro and in vivo.

[Endobronchial brachytherapy with high dose rate 192Ir afterloading technique using a new applicator]

Recently, high dose rate endobronchial brachytherapy has been carried out for the treatment of lung cancer. We devised a new applicator for Ir-192 high dose rate brachytherapy that can position the source in the center of the bronchial lumen, and tried to set up reference points according to bronchial diameter, for optimal dose distribution. Treatment consisted of external beam radiotherapy (40-60 Gy in 4-6 weeks) and endobronchial brachytherapy (6 Gy x 3 fractions for curative intent, 10 Gy x 1 fraction for palliative intent). Reference dose points were 3, 5, 7 and 10 mm from the center of the source according to bronchial diameter. We treated 19 patients with endobronchial brachytherapy and used the new applicator in 13 of them. We could place the applicator in all 13 patients, and no remarkable side effects were observed during the observation period. Our newly designed applicator will help to reduce radiation side effects caused by irradiation overdose due to adherence of the source to the bronchial wall. The reference point should be set according to bronchial diameter not only for curative intent but also palliative intent.

Prevention of lpr-graft-versus-host disease and transfer of autoimmune diseases in normal C57BL/6 mice by transplantation of bone marrow cells plus bones (stromal cells) from MRL/lpr mice

C57BL/6 (B6) (H-2b) mice were lethally irradiated and then reconstituted with T cell-depleted MRL/Mp-lpr/lpr (MRL/lpr) (H-2k) bone marrow cells. The mice showed a short survival with splenic atrophy and fibrosis, as previously described as lpr-graft-vs-host disease (GVHD). However, when these mice received bone marrow transplantation (BMT) plus bone grafts (to recruit donor-derived stromal cells) from MRL/lpr mice, they survived for almost 1 yr without showing GVH symptoms, but showing autoimmune symptoms such as elevated serum IgG2a concentrations, autoantibody production and glomerulonephritis. When MRL/lpr bone marrow cells plus MRL/+ bones (instead of MRL/lpr bones) were transplanted into B6 mice, such improved survival was also obtained, although the MRL/+ bone grafts were less effective in prolonging survival than MRL/lpr bone grafts. H-2 typing of stromal cells in the bone marrow of the B6 mice revealed that the stromal cells had been replaced by donor(H-2k) derived stromal cells. Analyses of TCR repertoires showed that the percentage of CD4+V beta 8.1,2+ cells significantly decreased in the B6 mice that received bone marrow transplantation plus bone grafts from MRL/lpr mice. These findings suggest that stromal cells present in the bone marrow play a crucial role in the development of lpr-GVHD and autoimmune diseases.

Increase in lectin binding sites on epithelial cells by chronic bladder infection in rats

Using lectin histochemistry we assessed whether chronic bladder infection modifies carbohydrate residues of glycoconjugates on uroepithelial cells in rats. The bladder infection was produced by implanting a knotted silk thread with Escherichia coli into the bladder. One or 4 weeks after the implantation the bladder was excised, incubated with sixteen biotinylated lectins and stained. The bladder epithelia as a whole stained more strongly positive for eight lectins in the infected rats than in the control rats having a sterile silk thread in the bladder. In the infected rats, the superficial epithelial layer that stained negative for Arachis hypogaea (PNA) in the controls became strongly positive for PNA, whereas the middle and deep epithelial layers increased in staining for Canavalia ensiformis and six other lectins. These results indicate that chronic bladder infection increases carbohydrate residues on uroepithelial cells and may facilitate bacterial adherence to uroepithelial cells.

Increased plasma level of platelet-activating factor (PAF) and decreased serum PAF acetylhydrolase (PAFAH) activity in adults with bronchial asthma

We evaluated the plasma level of platelet-activating factor (PAF), a chemical mediator that induces various symptoms of bronchial asthma, and the activity of serum PAF acetylhydrolase (PAFAH), an enzyme that specifically inactivates PAF, in adults with bronchial asthma. Measurements were made by radioimmunoassay of samples obtained from 137 adult asthmatic patients (137 cases examined in remission and from among these 41 cases were also measured at the time of an asthmatic attack) 59 adult patients with untreated pulmonary tuberculosis and 106 healthy adult volunteers. It was demonstrated that the plasma PAF level was markedly higher and the serum PAFAH activity markedly lower in the asthmatic patients, both in remission and at the time of asthmatic attack, than in the healthy volunteers. The plasma PAF level was more closely associated with asthma both in remission and at the time of asthmatic attack than with pulmonary tuberculosis, whereas there was no significant difference in the serum PAFAH activity between the two diseases. The low serum PAFAH activity in the asthmatic patients may have been due to saturation as a result of continuous reaction to the increased plasma PAF level in those patients.

Prevention of lpr-graft-versus-host disease and transfer of autoimmune diseases in normal C57BL/6 mice by transplantation of bone marrow cells plus bones (stromal cells) from MRL/lpr mice

C57BL/6 (B6) (H-2b) mice were lethally irradiated and then reconstituted with T cell-depleted MRL/Mp-lpr/lpr (MRL/lpr) (H-2k) bone marrow cells. The mice showed a short survival with splenic atrophy and fibrosis, as previously described as lpr-graft-vs-host disease (GVHD). However, when these mice received bone marrow transplantation (BMT) plus bone grafts (to recruit donor-derived stromal cells) from MRL/lpr mice, they survived for almost 1 yr without showing GVH symptoms, but showing autoimmune symptoms such as elevated serum IgG2a concentrations, autoantibody production and glomerulonephritis. When MRL/lpr bone marrow cells plus MRL/+ bones (instead of MRL/lpr bones) were transplanted into B6 mice, such improved survival was also obtained, although the MRL/+ bone grafts were less effective in prolonging survival than MRL/lpr bone grafts. H-2 typing of stromal cells in the bone marrow of the B6 mice revealed that the stromal cells had been replaced by donor(H-2k) derived stromal cells. Analyses of TCR repertoires showed that the percentage of CD4+V beta 8.1,2+ cells significantly decreased in the B6 mice that received bone marrow transplantation plus bone grafts from MRL/lpr mice. These findings suggest that stromal cells present in the bone marrow play a crucial role in the development of lpr-GVHD and autoimmune diseases.

Breath-hold MR measurements of blood flow velocity in internal mammary arteries and coronary artery bypass grafts

Breath-hold velocity-encoded cine MR (VENC-MR) imaging is a feasible method for measuring phasic blood flow velocity in small vessels that move during respiration. The purposes of the current study are to compare breathhold VENC-MR measurements of flow velocities in the internal mammary arteries (IMA) with nonbreath-hold measurements and to characterize the systolic and diastolic flow velocity curves in a cardiac cycle in native IMA and IMA grafts. Flow velocity in 30 native IMA and 8 IMA grafts were evaluated with a breath-hold VENC-MR sequence with K-space segmentation and view-sharing reconstruction (TR/TE = 16/9 msec, VENC = 100 cm/s). In 10 native IMA, nonbreath-hold VENC-MR images were acquired as well for comparison. Breath-hold VENC-MR imaging showed significantly higher systolic and diastolic peak velocities in native IMA (43.1 cm/second +/- 15.0 and 10.0 cm/second +/- 4.8), in comparison to those of nonbreath-hold VENC-MR imaging (27.6 cm/second +/- 10.2 and 7.3 cm/second +/- 3.9, P < .05). The diastolic/systolic peak velocity ratio in the IMA grafts (.88 +/- .41) was significantly higher than that in native IMA (.24 +/- .08, P < .01). Interobserver variability in the flow velocity measurement was less than 4%. Breath-hold VENC-MR imaging demonstrated higher peak flow velocity in the IMA than nonbreath-hold VENC-MR imaging. This technique is a rapid and effective method for the noninvasive assessment of blood flow velocity in IMA grafts.

Consideration on moments of outflow profile in liver perfusion system with change in perfusate flow rate using oxacillin as model drug

The effect of perfusate flow rate on hepatic structure and hepatic uptake kinetics was investigated using oxacillin as a model drug and bovine serum albumin (BSA) as a reference substance in the liver perfusion system from the standpoint of a dispersion model and moment characteristics. The estimated recovery ratio (FH) of oxacillin was about 40% which was independent of the change in perfusate flow rate. The mean transit time (tH) of oxacillin decreased with an increase in flow rate, while the relative variance (sigma 2/t2H) of oxacillin was independent of the flow rate. The tH of BSA decreased with an increase in the flow rate to the same extent as that of oxacillin, while sigma 2/t2H of BSA was independent of flow rate. When the dispersion model is adopted as a model system to analyze hepatic perfusion data following the pulse input, the moment characteristics (FH, tH and sigma 2/t2H) are given in complicated equations. It is demonstrated by the present investigation that these moment equations can be extensively simplified for a drug with a medium extraction ratio (FH > 50%), i.e., FH is independent of the distribution, both FH and tH are independent of the dispersion process in the hepatic blood space, and both tH and sigma 2/t2H are independent of the elimination. Thus, it is shown that FH and tH are exactly the indices of elimination and distribution, respectively, and sigma 2/t2H is the index of dispersion in the blood space plus nonequilibrium in the hepatic distribution.

Cognitive function in rats with alcohol ingestion

The effect of alcohol ingestion on learning disturbances was tested in rats. Rats were fed either an alcohol solution or a nonalcohol solution. The concentration of acetylcholine in the whole brain was significantly lower in rats fed with alcohol than rats fed without alcohol. Passive avoidance learning shows a lower tendency in rats with alcohol compared to rats without alcohol, but the alcohol and control groups did not differ in passive avoidance learning. We suggest that alcohol may disturb acetylcholine metabolism in the brain.

Portal vein embolization with steel coils and absolute ethanol: a comparative experimental study with canine liver

Portal vein embolization (PVE) is expected to have an adjuvant effect on the treatment of human liver tumors with transcatheter hepatic arterial embolization (TAE). In this experimental study, PVE was tried using two kinds of embolic materials, steel coils (coils) and absolute ethanol (ethanol). The aim of this article is to compare the effectiveness between the two methods. Five dogs and 12 dogs were treated with coils and ethanol, respectively. The second order portal branches were embolized. Embolization effects of each embolic material on the hepatic vessels and the liver parenchyma were studied angiographically and histologically. PVE with coils achieved immediate occlusion of the embolized vessels in all dogs. Unexpectedly, unembolized vessels were also constricted and/or obstructed in 4 of 5 dogs during a 4-week follow-up period. Histological examination showed no hepatic necrosis in all dogs. By contrast, in the dogs treated with ethanol, venous occlusion was achieved immediately after embolization with ethanol of 0.4 mL/kg or more. The embolized vessels remained occluded and no obstruction of unembolized vessels was observed until 4 weeks after embolization. Hepatic necrosis was observed in the segments where portal veins were occluded. The degree of parenchymal damage was proportional to the injected ethanol dose. Judging from these results, ethanol is likely to be more suitable than coils as an embolic material for PVE. PVE with coils is often dangerous because unembolized vessels might be occluded unexpectedly. For the clinical use of PVE with ethanol, the appropriate dose of injection should be investigated.

Appearance of free radicals in the guinea pig inner ear after noise-induced acoustic trauma

The emergence of superoxide anion radicals (O2-) in the guinea pig inner ear following acoustic trauma was investigated by histochemical methods. Five minutes after exposure to sound at 120-125 dB SPL for 3 h, an O2- reaction product was detected in the cochlea along the luminal membrane of the marginal cells of the stria vascularis. This reaction product could not be found at 30 min, but reappeared at 2 h. The first appearance of O2- is not explainable by our studies, but the second appearance may be related to recirculation of strial blood flow after blood flow stasis. The present observations raise the possibility that free radicals are produced in the inner ear after acoustic trauma and lead to inner ear damage.

Molecular cloning and sequencing of the hcs gene, which encodes 3-hydroxy-3-methylglutaryl coenzyme A synthase of Schizosaccharomyces pombe

We have cloned and sequenced the hcs gene, which is thought to encode a 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) synthase consisting of 447 amino acids, from the fission yeast Schizosaccharomyces pombe. The predicted amino acid sequence of the hcs product of S. pombe has homology with the HMG-CoA synthase of rat (47.8%), chicken (49.2%), hamster (47.1%) and human cells (46.9%). One of the hcs genes was replaced with a marker gene in the diploid cell. No viable hcs-disrupted haploid was isolated after tetrad dissection, suggesting that the hcs gene is essential for growth. However the hcs-defective mutant could be grown on a medium containing 5 mg/ml mevalonate. These results strongly support that the hcs gene encodes HMG-CoA synthase and S. pombe contains a single copy of the hcs gene.

Hepatocellular carcinoma complicating biliary cirrhosis caused by biliary atresia: report of a case

A case of hepatocellular carcinoma complicating biliary cirrhosis caused by biliary atresia is reported. The patient had persistent severe jaundice with hepatosplenomegaly. A liver tumor was suspected because of the elevated serum alpha-fetoprotein and was shown by ultrasonography at 6 years of age. The tumor was treated with percutaneous ethanol injection therapy (PEIT). Nine months after initiation of PEIT, the patient died of massive bleeding from a metastatic tumor.

Pharmacological study of dihydroetorphine in cloned mu-, delta- and kappa-opioid receptors

We investigated the binding characteristics of dihydroetorphine, 7,8-dihydro-7 alpha-[1-(R)-hydroxy-1-methylbutyl]-6, 14-endoethanotetrahydro-oripavine, and its effect on the inhibitory system of cyclic AMP production using cloned mu-, delta- and kappa-opioid receptors expressed on Chinese hamster ovary cells. The Ki values of dihydroetorphine for the mu-, delta- and kappa-opioid receptors were 4.5 x 10(-10). 1.8 x 10(-9) and 5.7 x 10(-10) M, respectively. On the other hand, those of morphine were 1.9 x 10(-9), 1.4 x 10(-6) and 1.3 x 10(-7) M, respectively. Through all of these three types of opioid receptors, dihydroetorphine inhibited forskolin (10 microM)-stimulated cyclic AMP production via pertussis toxin-sensitive G protein(s), and the inhibitory effects were antagonized by co-application with opioid receptor antagonists. The IC50 values of dihydroetorphine for the inhibition of cyclic AMP production through the mu-, delta- and kappa-opioid receptors were 4.2 x 10(-11), 8.6 x 10(-10) and 4.3 x 10(-9) M. respectively. On the other hand, those of morphine were 2.6 x 10(-8), 2.6 x 10(-6) and 1.9 x 10(-6) M, respectively. These results indicate that dihydroetorphine, unlike morphine which preferentially binds the mu-opioid receptor, binds not only mu- but also delta- and kappa-opioid receptors with high affinity and acts as a more potent agonist than morphine for all of the three types of receptors.

Localization of furin to the trans-Golgi network and recycling from the cell surface involves Ser and Tyr residues within the cytoplasmic domain

Furin is a membrane-associated endoprotease that catalyzes cleavage of precursor proteins at Arg-X-Lys/Arg-Arg sites. Although, at steady state, furin is predominantly found in the trans-Golgi network (TGN), it also cycles between the TGN and the cell surface. Recently, the cytoplasmic tail of furin has been shown to be sufficient for its localization to the TGN. Within the cytoplasmic domain, there are Ser residues, which we now show are sites for phosphorylation by casein kinase II in vitro, and a Tyr-containing sequence, both of which have been shown to be important for other TGN proteins to localize to this compartment. In the present study, we show by site-directed mutagenesis that these residues are important for TGN localization and recycling of furin. Mutation of the Ser residues abrogated the TGN localization. By contrast, mutation of the Tyr residue did not affect the TGN localization but impaired the internalization from the plasma membrane. These observations suggest that distinct cytoplasmic determinants are responsible for retention in the TGN and retrieval from the cell surface of furin.

A second mutant allele of furin in the processing-incompetent cell line, LoVo. Evidence for involvement of the homo B domain in autocatalytic activation

Furin is a Golgi membrane-associated endoprotease that is involved in cleavage of various precursor proteins predominantly at Arg-X-Lys/Arg-Arg sites. Furin itself is synthesized as an inactive precursor, which is activated through intramolecular autocatalytic cleavage at an Arg-X-Lys-Arg site. We previously found that human colon carcinoma LoVo cells have a frameshift mutation within the homo B domain of furin and thereby lack processing activity toward Arg-X-Lys/Arg-Arg sites. In this study, however, we identified a second furin mutation in this cell line. The mutation, a replacement of a conserved Trp residue within the homo B domain with Arg, results in lack of processing activity of the mutant furin. The combination of both mutations can account for the recessive nature of the processing incompetence of LoVo cells. Immunofluorescence analysis with three distinct anti-furin monoclonal antibodies revealed that neither furin mutant underwent the autocatalytic activation or left the endoplasmic reticulum for the Golgi. These data indicate that the homo B domain as well as the catalytic domain is required for autocatalytic activation of furin.

Receptor-linked antigen delivery system. Importance of autologous alpha 2-macroglobulin in the development of peptide vaccine

We have hijacked a process of the receptor-mediated endocytosis to transport peptide antigens into antigen presenting cells (APCs) for the purpose of increasing the level of antigen presentation (named Receptor-Linked Antigen Delivery System (R-LADS)). By coupling an endogenous plasma proteinase inhibitor alpha 2-macroglobulin (alpha 2M) to a synthetic peptide having a partial sequence of HIV-1 envelope protein, alpha 2M was made to carry the peptide into APCs as a part of the normal alpha 2M cycle, which resulted in an increased production of specific antibodies against the peptide (Mitsuda, S., Nakagawa, T., Osada, T., Shimamoto, T., Nakazato, H. and Ikai, A. (1993) Biochem. Biophys. Res. Commun. 194, 1155-1160). We demonstrate here that this procedure becomes a more efficient tool for antibody production when autologous transporter protein was used. By using murine alpha 2M (m alpha 2M) instead of heterologous human alpha 2M (h alpha 2M) when mice were experimental animals, we were able to dramatically enhance the production level of anti-HIV-1 peptide antibodies and shorten the period which is needed for antibody production. We aim to develop effective peptide vaccines by further improving this system.

Moment analysis of stereoselective biliary excretion and chiral inversion of ketoprofen enantiomers in perfused rat liver

The stereoselective local disposition of ketoprofen was evaluated by the single-pass perfusion experiment following a bolus injection of R(-)- or S(+)-ketoprofen into the liver from the portal vein. The elution time profiles of enantiomers into the hepatic vein and the excretion time profiles into the bile were kinetically assessed by local moment analysis. The hepatic recovery ratios (FH) of both enantiomers were < 1%, and the mean hepatic transit times (tH) were approximately 7 s. After the injection of S-ketoprofen into the liver, the biliary excretion ratio (Fb) of total S-ketoprofen was 68% (15% S-ketoprofen and 53% glucuronide) and the mean biliary transit time (tb) of S-ketoprofen was 10 min. R-Ketoprofen inversion from S-ketoprofen was not observed in either the perfusate or in the bile. After the injection of R-ketoprofen, the Fb of total R-ketoprofen was 12% (3% R-ketoprofen and 9% glucuronide), and tb of R-ketoprofen was 8 min. The Fb of total S-ketoprofen inverted from R-ketoprofen was 24% (7% S-ketoprofen and 17% glucuronide), and the tb of inverted S-ketoprofen was 17 min. Forty-six percent of R-ketoprofen was inverted to S-ketoprofen during a single pass through the rat liver, and the mean inversion time was 7.5 min. It was concluded that the unidirectional chiral inversion of ketoprofen was stereospecific, and the hepatic uptake and biliary excretion were stereo-nonspecific.

[De novo aneurysm associated with a persistent primitive trigeminal artery: case report]

This paper presents a case of a de novo unruptured anterior communicating aneurysm associated with a persistent primitive trigeminal artery. The patient was a 65-year-old female with tinitis, for whom computed tomography with contrast medium indicated right dural enhancement. Dural arteriovernous malformation was suspected and angiography was thus conducted. A right persistent primitive trigeminal artery was demonstrated but no aneurysm could be found. Six years later, magnetic resonance angiography indicated an aneurysm on the anterior communicating artery. It was subsequently removed by surgery. A persistent primitive artery is frequently found to accompany aneurysm but de novo aneurysm associated with such an artery does not appear in the literature to date. The authors emphasize the importance of follow-up angiography in cases of persistent primitive artery not accompanied by an aneurysm.

Natural killer cell response in the inner ear

Heterologous tumor cells (human chronic myelogenous leukemia K-562 cells) were injected into the perilymph and skin in guinea pigs in order to study the induction of NK cell activity in the inner ear. An in vitro transmission electron microscopic and immunohistochemical study showed that K-562 cells were attacked by guinea pig large granular lymphocytes. K-562 cells injected through the round window membrane were found to be targeted by NK cells emerging from surrounding venules after 7 to 9 days. During this time morhological changes occurred in the organ of Corti and stria vacularis. These findings suggest that the inner ear response to foreign cells induces activation and invasion of NK cells which occur relatively late compared with those in other organs such as skin.

[Simultaneous intraluminal irradiation and hyperthermia treatment for esophageal carcinoma]

The combination of radiotherapy and thermotherapy has the greatest antitumor effect when delivered simultaneously. We developed and have clinically used an applicator that enables simultaneous intraluminal irradiation and hyperthermia delivery for the treatment of locally invasive esophageal carcinoma. In a phase 1 study, 40 Gy of external irradiation was delivered followed by simultaneous intraluminal hyperthermia and radiotherapy once weekly for three weeks. Intraluminal hyperthermia was delivered to the mucosal surface at 42 to 44 degrees C for 30 minutes. Intraluminal irradiation (3 Gy) was delivered to a submucosal depth of 5 mm after the first 15 minutes of hyperthermia. This treatment may increase current treatment results for locally invasive esophageal carcinoma, which have otherwise been maximized.

Amino acid sequences for human urinary bikunin (trypsin inhibitor) isomers

Our previous study has shown that urinary bikunin has four major isomers, which differ with respect to the sulfation ratio in a glycosaminoglycan chain but which do not exhibit any differences in amino acid composition, N-terminal amino acid sequence, C-terminal amino acid, sialic acid and uronic acid content. In this study, the amino acid sequences of the four isomers were examined. Sequence analysis showed that the amino acid sequence of the four isomers was completely identical and was also the same as the amino acid sequence deducted from cDNA encoding bikunin. We conclude that the charge heterogeneity of urinary bikunin is due to only a difference in the sulfation ratio of a glycosaminoglycan chain.

[Philadelphia chromosome-negative chronic myelogenous leukemia with trisomy 13]

Trisomy 13, as a sole karyotypic abnormality in acute leukemia, has been reported in several cases. However, in chronic myelogenous leukemia (CML), only two cases with this abnormality were reported so far. We describe herein a 68-year-old case with Philadelphia chromosome-negative CML and trisomy 13. Leukocytosis was pointed out during the treatment for other diseases. After 7 months, abrupt increase in leukocyte count (108,000/microliters) and splenomegaly developed. Decreased neutrophil alkaline phosphatase activity and morphological features fulfilled the diagnostic terms for CML. However, the karyotypic analysis revealed trisomy 13 instead of Philadelphia chromosome, and the BCR gene rearrangement was not detected. In cases with acute leukemia accompanied by trisomy 13, malignant transformation of an immature hematopoietic precursor cell has been suggested by the expression of antigens characteristic of both the myeloid and lymphoid lineage. In a few cases with myelodysplastic syndrome, a multipotent stem cell disorder, trisomy 13 has also been reported. From these standpoints, there might be a possibility that trisomy 13 as a sole abnormality in hematologic disorders would be related to tumorigenesis in the levels of multipotent stem cells.