Iodine contrast volume reduction in preoperative transcatheter aortic valve implantation computed tomography: Comparison with 64- and 256-multidetector row computed tomography.

INTRODUCTION: This study aimed to compare the vascular enhancement and radiation dose in preoperative transcatheter aortic valve implantation (TAVI) computed tomography (CT) with a reduced contrast medium (CM) using volume scans in 256-multidetector row CT (MDCT) with a standard CM using 64-MDCT. METHODS: This study included 78 patients with preoperative TAVI CT with either 64- or 256-MDCT. The CM was injected at 1.5 mL/kg in the 64-MDCT group and 1.0 mL/kg in the 256-MDCT group. We compared vascular enhancement of the aortic root and access routes, image quality (IQ) scores, and radiation dose in both groups. RESULTS: Despite the reduced CM (by 33 %) in the 256-MDCT group, the mean vascular enhancement of the right and left subclavian arteries was significantly higher than that in the 64-MDCT group [284 and 267 Hounsfield units (HU) vs. 376 and 359 HU; p < 0.05]; however, no significant differences in the mean vascular enhancement in the ascending aorta, abdominal aorta at the celiac level, and bilateral common femoral arteries were observed between the two groups (p > 0.05 for all). The median IQ scores at the aortic root were higher in the 256-MDCT group than in the 64-MDCT group (3 vs. 4; p < 0.05), and those at the femoral access routes were comparable (4 vs. 4; p = 0.33). The mean effective dose was significantly reduced by 30 % in the 256-MDCT group (23.6 vs. 16.3 mSv; p < 0.05). CONCLUSION: In preoperative TAVI CT, volume scans using 256-MDCT provide comparable or better vascular enhancement and IQ with a 30 % reduction in CM and radiation dose than those using 64-MDCT. IMPLICATIONS FOR PRACTICE: Volume scan using 256-MDCT for preoperative TAVI CT may reduce CM and radiation dose in TAVI patients with renal dysfunction.

Growth site localization of Rho1 small GTP-binding protein and its involvement in bud formation in Saccharomyces cerevisiae.

The Rho small GTP-binding protein family regulates various actomyosin-dependent cell functions, such as cell morphology, locomotion, cytokinesis, membrane ruffling, and smooth muscle contraction. In the yeast Saccharomyces cerevisiae, there is a homologue of mammalian RhoA, RHO1, which is essential for vegetative growth of yeast cells. To explore the function of the RHO1 gene, we isolated a recessive temperature-sensitive mutation of RHO1, rho1-104. The rho1-104 mutation caused amino acid substitutions of Asp 72 to Asn and Cys 164 to Tyr of Rho1p. Strains bearing the rho1-104 mutation accumulated tiny- or small-budded cells in which cortical actin patches were clustered to buds at the restrictive temperature. Cell lysis and cell death were also seen with the rho1-104 mutant. Indirect immunofluorescence microscopic study demonstrated that Rho1p was concentrated to the periphery of the cells where cortical actin patches were clustered, including the site of bud emergence, the tip of the growing buds, and the mother-bud neck region of cells prior to cytokinesis. Indirect immunofluorescence study with cells overexpressing RHO1 suggested that the Rho1p-binding site was saturable. A mutant Rho1p with an amino acid substitution at the lipid modification site remained in the cytoplasm. These results suggest that Rho1 small GTP-binding protein binds to a specific site at the growth region of cells, where Rho1p exerts its function in controlling cell growth.

Chromosome abnormalities of leukemia cells in adult patients with T-cell leukemia.

Chromosomes of 30 patients with adult T-cell leukemia were analyzed. Chromosome abnormalities were found in all the patients examined. The modal chromosome number of abnormal cells was hypodiploid in 2 patients, diploid in 14, and hyperdiploid in 9. The remaining 5 patients had bimodal chromosome numbers (diploid and hyperdiploid modes). Although all the patients showed various numerical or structural chromosome abnormalities, they also had common chromosome abnormalities. Aberrations of chromosome 1 were noted in 20 of the 30 patients, aberrations of chromosome 3 were seen in 20, trisomy 6 or 6q- was found in 17, aberrations of chromosome 10 were noted in 16, aberrations of the long arm of chromosome 14 were seen in 9, and trisomy 18 was seen in 7. There was no particular relationship between the difference in clinical symptoms and disparity in chromosome abnormalities.

Association of the Rho family small GTP-binding proteins with Rho GDP dissociation inhibitor (Rho GDI) in Saccharomyces cerevisiae.

The small GTP-binding proteins of the Rho family, consisting of the Rho, Rac, and Cdc42 subfamilies, are implicated in various cell functions, such as cell shape change, cell motility and cytokinesis, through reorganization of actin cytoskeleton. Rho GDI is a general regulator which forms a complex with the GDP-bound inactive form of the Rho family members and inhibits their activation. We have purified Rho GDI from the yeast Saccharomyces cerevisiae, cloned its gene, and named it RDII (Rho GD). In this study, we have further characterized yeast Rho GDI. Rho GDI was found in the cytosol by immunoblot and immunofluorescence microscopic analyses. Rho1p and Cdc42p were co-immunoprecipitated with Rho GDI from the cytosol. This immunoprecipitated Rho1p was mainly bound to GDP. In the disruption mutant of Rho GDI, which did not show any apparent phenotype, both Rho1p and Cdc42p were also present in the cytosol. These results indicate that yeast Rho GDI possesses properties similar to those of mammalian Rho GDI, and that there is a cytosolic factor which functionally substitutes for Rho GDI in yeast.

Molecular cloning of the human cDNA for a stimulatory GDP/GTP exchange protein for c-Ki-ras p21 and smg p21.

We have previously purified smg GDP dissociation stimulator (GDS) from bovine brain and isolated its cDNA from a bovine brain cDNA library. smg GDS stimulates the GDP/GTP exchange reaction of a group of small GTP-binding proteins (G proteins), including at least c-Ki-ras p21, smg p21A, smg p21B, rhoA p21 and rhoB p21, by stimulating the dissociation of GDP from and the subsequent binding of GTP to each small G protein. In this study, we have isolated and sequenced the cDNA of smg GDS from a human brain cDNA library using the cloned bovine smg GDS cDNA. The cDNA has an open reading frame encoding a protein of 558 amino acids with a calculated Mr value of 61,122. Human smg GDS shares 93% nucleotide and 96% amino acid sequence homologies with bovine smg GDS. The isolated cDNA is expressed in Escherichia coli, and the encoded protein shows the physical and functional properties similar to those of bovine smg GDS.

Characterization of thromboxane A2/prostaglandin H2 receptors and histamine H1 receptors in cultured guinea-pig tracheal smooth-muscle cells.

We characterized thromboxane A2/prostaglandin H2 (TXA2/PGH2) receptors and histamine H1 receptors in Guinea-pig cultured tracheal smooth-muscle cells (TSMC). [3H]SQ 29,548 (a TXA2 antagonist)-binding sites were saturable and a high affinity with a dissociation constant of 6.2 +/- 0.60 nM (mean +/- S.E.) and a receptor density of 46 +/- 4.6 fmol/10(6) cells. [3H]SQ 29548 binding was completely inhibited by TXA2 mimetics or antagonists. Intracellular calcium concentration ([Ca2+]i) in TSMC was increased with U46619 stimulation and the increase was attenuated by TXA2 antagonists, the potencies of which correlated with those inhibiting the activities of the [3H]SQ 29548 binding. [3H]Mepyramine (a H1 antagonist)-binding sites were also present in TSMC. [3H]Mepyramine had a single class of low-affinity-binding sites with a dissociation constant of 2.6 +/- 0.081 microM and a receptor density of 10.6 +/- 0.11 nmol/mg protein. [3H]Mepyramine binding in TSMC membrane was inhibited by H1 antagonists, but not by H2 antagonists. The inhibition constants of mepyramine in TSMC were 910-times lower than those in tracheal membranes. In contrast, the histamine-induced increase in [Ca2+]i in TSMC was inhibited in the presence of low concentrations of H1 antagonists. All these observations provide evidence that TXA2/PGH2 receptors, mepyramine-binding sites and/or H1 receptors are expressed in cultured TSMC.

Taurine prevents the decrease in expression and secretion of extracellular superoxide dismutase induced by homocysteine: amelioration of homocysteine-induced endoplasmic reticulum stress by taurine.

BACKGROUND: Hyperhomocysteinemia is an independent risk factor for atherosclerosis. Homocysteine has been shown to induce endoplasmic reticulum (ER) stress in vascular endothelial cells. ER stress is a condition in which glycoprotein trafficking is disrupted and unfolded proteins accumulate in the ER. ER molecular chaperons, such as GRP78, are induced and an ER resident kinase, PERK, is activated when cells are subjected to ER stress. Conversely, taurine is reported to have antiatherogenic effects by unknown mechanisms. To elucidate the mechanisms by which homocysteine induces atherosclerosis and taurine prevents it, we examined whether homocysteine and taurine affect the expression and secretion of extracellular superoxide dismutase (EC-SOD), a glycoprotein secreted from vascular smooth muscle cells (VSMCs) that protects the vascular wall from oxidative stress. METHODS AND RESULTS: We assessed the expression of EC-SOD and GRP78 mRNA in cultured rat VSMCs by Northern blot analysis. The EC-SOD protein secreted into the culture medium was examined by Western blot analysis. Homocysteine (5 mmol/L) and other ER stress inducers, including A23187, were found to decrease EC-SOD mRNA expression and protein secretion. Furthermore, they upregulated GRP78 mRNA expression and activated PERK. Taurine (0.5 to 10 mmol/L), conversely, prevented these actions induced by homocysteine. CONCLUSIONS: Homocysteine induces ER stress and reduces the secretion and expression of EC-SOD in VSMCs, leading to increased oxidative stress in the vascular wall. Taurine restores the secretion and expression of EC-SOD by ameliorating ER stress induced by homocysteine.

Angiotensin II induces circadian gene expression of clock genes in cultured vascular smooth muscle cells.

BACKGROUND: Daily rhythms of mammalian physiology and endocrinology are regulated by circadian pacemakers. The master circadian pacemaker resides in the suprachiasmatic nucleus, which is located in the hypothalamus of the brain, but circadian oscillators also exist in peripheral tissues. Because many studies have demonstrated apparent circadian variations in the frequency of cardiovascular disorders, it is of great interest to investigate a possible relation between circadian gene expression and cardiovascular function. We examined whether a circadian oscillation system exists in the aorta and/or in cultured vascular smooth muscle cells (VSMCs). METHODS AND RESULTS: The mRNA levels of clock genes were assayed by northern blot analysis. The mouse aorta showed a clear circadian oscillation in the expression of mPer2, dbp, and Bmal1. Brief treatment of VSMCs with angiotensin II induced a robust increase in mPer2 gene expression, followed by a marked reduction in mPer2 mRNA levels and subsequent synchronous cycling of mPer2, dbp, and Bmal1 mRNAs. The induction of mPer2 in VSMCs by angiotensin II was completely abolished by treatment with CV11947, a specific angiotensin II type1 receptor antagonist. CONCLUSIONS: The present results demonstrate that the aorta and VSMCs possess a circadian oscillation system which is comparable to that of the suprachiasmatic nucleus and that the circadian gene expression in VSMCs is induced by angiotensin II through the angiotensin II type1 receptor. Our in vitro system will provide a useful tool to further analyze the physiological significance of the peripheral clock in cardiovascular function.

Malignant glomus tumor: a case report and review of the literature.

This report concerns a malignant glomus tumor, a rare soft tissue tumor that was examined immunohistochemically and ultrastructurally. It occurred in a 44-year-old male patient who had suffered from dull pain and stiffness in the right thigh for 10 months. Radiographic examination revealed a well-defined osteolytic lesion in the diaphysis of the right femur. Hypervascularity of the tumor was observed angiographically. Computed tomographic and magnetic resonance examinations showed an intramuscular mass invading the marrow space of the femur. Wide resection was performed after open biopsy. Histologically, round to polygonal tumor cells revealed a uniform appearance of round to ovoid nuclei with single large nucleoli and slightly eosinophilic cytoplasm, forming solid sheets of cells interrupted by vessels of varying size. A few mitotic figures and vascular invasion were observed. Immunohistochemically, vimentin and alpha-smooth muscle actin were stained intensely, and muscle actin was positive for tumor cells of the perivascular area. Tumor cells were negative for desmin, factor VIII-related antigen, S-100 protein, neurofilament, cytokeratin, and epithelial membrane antigen. Ultrastructurally, tumor cells were characterized by many cytoplasmic processes, pinocytotic vesicles, plasmalemmal dense plaques, and scattered microfilaments in the cytoplasm. Few cell junctions and focal basement membrane-like structures were observed. No recurrence or metastasis was noted 57 months after operation. This case was considered to be a malignant glomus tumor, that is, a glomangiosarcoma arising de novo.

8-Polycycloalkyl-1,3-dipropylxanthines as potent and selective antagonists for A1-adenosine receptors.

With the aim of characterizing the hydrophobic interactions between xanthines and the A1 receptor site, 1,3-dipropyl-8-substituted xanthines were synthesized. Introduction of a quaternary carbon and the conformationally restricted cyclopentyl moiety into the 8-position of xanthines enhanced the adenosine A1 antagonism. 1,3-Dipropyl-8-(3-noradamantyl)xanthine was identified to be a selective and the most potent A1 receptor antagonist reported to date. Under our structure-activity relationship, the 8-substituent of xanthine antagonists and the N6-substituent of adenosine agonists appears to bind to the same region of the A1 receptor.

5-HT3 receptor antagonists. 3. Quinoline derivatives which may be effective in the therapy of irritable bowel syndrome.

A series of quinolinecarboxylic acid derivatives has been previously described as a new class of 5-HT3 receptor antagonists due to deviation of a carbonyl moiety from the place of an aromatic ring in their minimum-energy conformations. These derivatives were evaluated in a wrap-restraint stress-induced defecation model in rats. Reference compounds, ondansetron (1), granisetron (2), and YM060 (4), potently inhibited a stress-induced increase in stools excreted from fed rats (ID50 = 0.27, 0.12, and 0.0052 mg/kg, po, respectively). However, quinoline derivatives exhibited different activities depending on structural class. 4-Hydroxyquinoline-3-carboxylic acid derivatives 5 and 6a possess high affinity for the 5-HT3 receptor (Ki = 6.1 and 1.5 nM, respectively) and exhibit potent activity in the Bezold-Jarisch (B-J) reflex test (ED50 = 0.0017 and 0.000 10 mg/kg, i.v., respectively), but they did not effectively inhibit the increase in fecal pellet output at the dose of 1 mg/kg, po. On the other hand, most of 1-substituted 2-oxoquinoline-4-carboxylates 10 showed less potent activity in the B-J reflex test than 1 or 2 but inhibited restraint stress-induced defecation more potently than 1 or 2. The ID50 value of endo-8-methyl-8- azabicyclo[3.2.1]oct-3-yl 1-isobutyl-2-oxo-1,2-dihydro-4- quinolinecarboxylate 10e was 0.013 mg/kg, po. With respect to the selected compounds 6a and 10e, effects of 5-HT- and thyrotropin-releasing hormone (TRH)-induced defecation, castor oil-induced diarrhea and wrap-restraint stress-induced colonic propulsion in rats were examined. These 5-HT3 receptor antagonists did not effectively inhibit castor oil-induced diarrhea, which has been reported not to be mediated via the 5-HT3 receptor. Although 10e showed 800-fold decreased potency compared with 4 in the B-J reflex test, 10e exhibited activity as potent as 4 in 5-HT- and TRH-induced defecation assays; 10e exhibited 7-fold increased potency compared with 4 in wrap-restraint stress-induced colonic propulsions. From these results, 10e appears to interact selectively with 5-HT3 receptors in the gastrointestinal system and might be effective in the therapy of irritable bowel syndrome (IBS).

Adenosine A1 antagonists. 2. Structure-activity relationships on diuretic activities and protective effects against acute renal failure.

Diuretic activities of xanthine or nonxanthine adenosine antagonists and their ameliorative effects against glycerol-induced acute renal failure in rats were investigated in order to clarify the physiological and pathological function of adenosine receptors in the kidney. Diuretic and natriuretic activities of a variety of adenosine antagonists clarified systematically for the first time that the blockade of A1 receptors is more important than that of A2 receptors in sodium and water excretion and support the hypothesis that endogenous intrarenal levels of adenosine directly enhance tubular sodium readsorption. Studies of structure-activity relationships of 8-substituted xanthines in the acute renal failure demonstrated that the activation of adenosine A1 receptor was an important factor in developing such a renal failure. A series of 8-(3-noradamantyl)xanthines exhibited the extremely potent diuretic and natriuretic activities (24; 2.5 micrograms/kg, po, the ratio of urinary excretion value in treated rats to urinary excretion value in control rats = 1.69, the ratio of Na+/K+ in treated rats to Na+/K+ in control rats = 1.76) and potent ameliorative effects against glycerol-induced acute renal failure (24; 10 micrograms/kg, ip, 55% inhibition). From our detailed studies of structure-activity relationships, we can speculate that some tissue differences of the adenosine A1 receptor might exist between kidney and brain and sites of action for adenosine antagonists could be different between two renal pharmacological assays. 1,3-Dipropyl-8-(3-noradamantyl)xanthine, KW-3902 (24), was chosen for further studies and is under development as a drug for treating the acute renal failure.

Indole derivatives as a new class of steroid 5 alpha-reductase inhibitors.

A series of indole derivatives with varied substituents on the alpha, beta-unsaturated double bond were synthesized and evaluated for their ability to inhibit rat prostatic 5 alpha-reductase. Compounds possessing an ethyl substituent at the beta-position of the double bond showed potent inhibitory activity. Among them, (Z)-4-{2-[[3-[1-(4,4'-difluorobenzhydryl)indol-5-yl]-2-pentenoy l]- amino]phenoxy}butyric acid (16, KF20405) showed the maximum potency with an IC50 value of 0.48 +/- 0.086 nM, which was 20-fold higher potency than 1 (MK-906). Compound 16 effectively inhibited DHT production 4 h after a 3 mg/kg oral administration. Several potent indole derivatives, 1 and 2 ((+/-)-ONO-3805), were tested versus rat and human isozymes. Nonsteroidal inhibitors such as indole derivatives and 2 were 2-3 orders of magnitude less potent for human type 2 isozyme than steroidal inhibitor 1 and expressed a significant species deference for these isozymes.

Synthesis of 2-imidazolidinylidenepropanedinitrile derivatives as stimulators of gastrointestinal motility.

Ranitidine (1), the histamine H2-receptor antagonist, has been previously reported to increase gastric emptying and gastric motility by inhibition of acetylcholinesterase (AChE) and enhancement of acetylcholine (ACh) release. In order to obtain potent gastroprokinetic agents, a new series of ranitidine derivatives (5-32) possessing a nitrogen atom instead of a sulfur atom (B) was synthesized and their AChE inhibitory activity and potentiating action on electrically evoked contractions of guinea pig ileum were evaluated. Modification of substituents R1 and R2 markedly influenced the activities. In particular, compound 19, (1-[2-[[[5-(piperidinomethyl)-2-furanyl]methyl]amino]-ethyl]-2- imidazolidinylidene)propanedinitrile fumarate, showed 20 and 100 times more potent AChE inhibitory activity and potentiating action on the ileal contraction, respectively, than ranitidine. Furthermore, compound 19 (KW-5092) enhanced gastrointestinal motility in anesthetized rabbits along with a negligible histamine H2-receptor blocking activity.

Adenosine A1 antagonists. 3. Structure-activity relationships on amelioration against scopolamine- or N6-((R)-phenylisopropyl)adenosine-induced cognitive disturbance.

The effects of a variety of adenosine A1 and A2 antagonists on N6-((R)-phenylisopropyl)adenosine (R-PIA)- and scopolamine-induced amnesias were investigated in rodents in order to clarify the role of adenosine receptors in learning and memory. Some of the selective adenosine A1 antagonists exhibited antiamnesic activities at several doses where they did not induce an increase of spontaneous locomotion. These results suggest that the blockade of A1 receptors is more important than that of A2 receptors in learning and memory. Detailed studies of structure-activity relationships of adenosine A1 antagonists in two amnesia models demonstrated that there were three types of adenosine A1 antagonists: (A) Compounds 3-5 (8-substituted 1,3-dipropylxanthines) ameliorated the shortened latency in both models. (B) Compounds 7-11 (8-substituted 1,3-dialkylxanthines) and 19-21 (imidazo[2,1-i]purin-5(4H)-one derivatives) ameliorated the shortened latency in the (R)-PIA-induced amnesia model but not in the scopolamine-induced amnesia model. (C) Compounds 14-16 ameliorated the shortened latency in the scopolamine model but not in the (R)-PIA model. Aminophenethyl-substituted compounds C did not exhibit adenosine A1 antagonism in vivo presumably due to rapid metabolism. The dramatic change in the activities of A and B could not be explained by their simple pharmacokinetic differences because both types of compounds showed clear blockade of central adenosine A1 receptors in the (R)-PIA model. 8-(3-Dicyclopropylmethyl)-1,3-dipropylxanthine (5) (KF15372) was chosen for further studies and is currently under preclinical development as a cognition enhancer.

KW-3902, a selective high affinity antagonist for adenosine A1 receptors.

1. We demonstrate that 8-(noradamantan-3-yl)-1,3-dipropylxanthine (KW-3902) is a very potent and selective adenosine A1 receptor antagonist, assessed by radioligand binding and cyclic AMP response in cells. 2. In rat forebrain adenosine A1 receptors labelled with [3H]-cyclohexyladenosine (CHA), KW-3902 had a Ki value of 0.19 nM, whereas it showed a Ki value of 170 nM in rat striatal A2A receptors labelled with [3H]-2-[p-(2-carboxyethyl)-phenethylamino]-5'-N-ethylcarboxamidoad enosine (CGS21680), indicating 890 fold A1 receptor selectivity versus the A2A receptor. KW-3902 at 10 microM showed no effect on recombinant rat A3 receptors expressed on CHO cells. 3. Saturation studies with [3H]-KW-3902 revealed that it bound with high affinity (Kd = 77 pM) and limited capacity (Bmax = 470 fmol mg-1 of protein) to a single class of recognition sites. A high positive correlation was observed between the pharmacological profile of adenosine ligands inhibiting the binding of [3H]-KW-3902 and that of [3H]-CHA. 4. KW-3902 showed potent A1 antagonism against the inhibition of forskolin-induced cyclic AMP accumulation in DDT1 MF-2 cells by the A1-selective agonist, cyclopentyladenosine with a dissociation constant (KB value) of 0.34 nM. KW-3902 antagonized 5'-N-ethylcarboxamidoadenosine-elicited cyclic AMP accumulation via A2B receptors with a KB value of 52 nM. 5. KW-3902 exhibited marked species-dependent differences in the binding affinities. The highest affinity was for the rat A1 receptor (ki = 0.19 nM) and these values for guinea-pig and dog A1 receptors were 1.3 and 10 nM, respectively.

Increased urinary levels of adrenomedullin in patients with cystitis.

In this study, we examined urinary levels of adrenomedullin (AM) in 18 healthy volunteers and 18 patients with cystitis. We also compared urinary levels of AM in 11 patients with cystitis before and after antibiotic treatment. Urinary AM concentrations were measured by a radioimmunoassay specific for human AM. Urinary AM levels in patients with cystitis were significantly elevated compared with those of healthy volunteers and correlated positively with the number of urine leukocytes. By antibiotic treatment, urinary AM levels significantly decreased as compared with before the treatment. By RNA blot analysis of AM transcript, we detected significant levels of AM mRNA in canine urinary bladder and ureter. Intravenous administration of lipopolysaccharide elevated the AM mRNA level in the urinary bladder. These data suggest that infection and inflammation stimulate AM production in the urinary tract, which results in increased urinary AM levels in patients with cystitis. Based on these results, it is deduced that AM participates in the pathophysiology of cystitis, and its urinary level could be used as an index of the degree of cystitis.

CFU-C abnormalities and cytochemical defects in bone marrow of adult patients during remission of acute leukemia.

Twenty-three adult patients in complete remission (CR) from acute leukemia were investigated for the steady-state bone marrow (BM) CFU-C concentration and the cytochemical findings of neutrophils and monocytes. There was considerable variation in CFU-C concentrations among patients. Patients with abnormality high or low values tended to relapse earlier. Repeated assays revealed constant CFU-C values in individual long-term cases of remission (4 cases). One case of M4 (myelomonocytic) and the case of M5b (monocytic) leukemia revealed a complete lack of nonspecific esterase activity in CR monocytes as well as initial leukemic promonocytes; they also showed abnormally high or low concentrations of CFU-C and relapsed early. This finding suggests that hematopoiesis in CR bone marrow occurs from abnormal stem cells common to initial, acute leukemic clones in such cases.

Prognostic significance of the morphological dysplastic changes in chronic myelogenous leukemia.

Various morphological dysplastic changes were observed in patients with chronic myelogenous leukemia, especially in the acute crisis. To clarify their significance, we divided 45 patients in the acute crisis into two groups by our scoring system, the dysplastic group and the non-dysplastic group. Five of 25 subjects in the non-dysplastic group entered complete remission. None of 20 subjects in the dysplastic group did so, and the mean survival after the onset of acute crisis is significantly shorter in the dysplastic group than in the non-dysplastic group. Some patients in the dysplastic group had obvious dysplastic changes several months before the acute crisis. These findings suggest that acute crises in some cases may occur with or be preceded by the development of dysplastic clones similar to myelodysplastic syndrome; these patients respond poorly to conventional chemotherapy.

Dual expression of lymphoid/basophil markers on single blast cells transformed from chronic myeloid leukemia.

A 27-yr-old man developed blastic crisis after the chronic phase of Philadelphia chromosome positive chronic myeloid leukemia (CML). The blast cells expressed terminal deoxynucleotidyl transferase (TdT)+/common acute lymphoblastic leukemia antigen (CALLA)+ phenotypes, corresponding to common ALL type. A vincristine plus prednisolone regimen initially suppressed the blastic proliferation, but the blasts soon reappeared as lymphoblasts, and 65% of them possessed basophil-like granules. Immunologic markers were not altered. The blasts were negative for myeloperoxidase, Sudan black B and periodic acid-Schiff reactions, but were positive for toluidine blue (TB) stain and supravital peroxidase (PO) stain using diaminobenzidine (DAB). These blasts were considered to have immature basophil granules. The supravital staining, for TB or PO in combination with fluorescinated-CALLA staining, directly revealed that single blasts expressed both basophil and lymphoid markers. This biphenotypic blast population was found to be a distinct clone from the initial crisis clone by cytogenetic examination. These findings suggest that the CML clone is derived from a multipotent stem cell common to lymphoid and myeloid lineages, or that dual markers may be expressed on transformed lymphoid or basophil clone as the result of differentiation infidelity probably determined by the genetic derangement in acute crisis.