Search PubMed⌕ Search

Biomedical subjects

T Inukai

Publications and source records attributed to T Inukai.

At least 19 recordsLinked to original sources
PubMed2003

Primary antiphospholipid syndrome associated with acute adrenal failure.

We describe a 48-year-old woman with primary antiphospholipid syndrome who developed acute adrenal failure after an operation for a uterine myoma. After surgery, she developed a preshock state with hypotension, hypoglycemia, and hyponatremia. A diagnosis of primary antiphospholipid syndrome was made based not only on her past history of skin ulceration and recurrent spontaneous abortions but also on the presence of anticardiolipin antibodies. An abdominal computed tomography showed a bilateral enlargement of the adrenal glands but no high-density region in either gland. The patient recovered from the shock-like syndromes after the administration of glucocorticoids. Because it is possible that patients with antiphospholipid syndrome have acute or chronic adrenal failure caused by repeated hemorrhage or thrombosis, it may be important to monitor adrenal function in patients when the presence of this antibody is detected.

Acute Disease↗
PubMed2002

Ligand activation of peroxisome proliferator-activated receptor gamma induces apoptosis of leukemia cells by down-regulating the c-myc gene expression via blockade of the Tcf-4 activity.

The peroxisome proliferator-activated receptor gamma (PPAR gamma), a member of the nuclear receptor superfamily, is expressed at highest levels in adipose tissue and functions as a central regulator in the process of adipocyte differentiation. In the present study, we showed that human leukemic cell lines, not only myeloid but also lymphoid, express PPAR gamma and its activation by natural ligand (15-deoxy-Delta(12,14) - prostaglandin J(2)) and synthetic ligand (troglitazone) profoundly inhibited their proliferation by induction of apoptosis preferentially in the serum-free culture. We pursued its mechanism using the representative cell lines, and found that induction of apoptosis was accompanied by caspase-3 activation and specifically blocked by its inhibitor. While status of several apoptosis-related molecules remained unchanged, the c-Myc expression was markedly down-regulated within 24 h after troglitazone treatment. The c-myc mRNA levels were dramatically reduced at 1 h and became undetectable at 12 h after troglitazone treatment, which proved to be accompanied by complete blockade of the Tcf-4 activity in the electrophoretic mobility shift assay. We succeeded in establishing HL-60 cell lines growing well in the presence of troglitazone in the long-term serum-free culture. They showed neither induction of apoptosis nor down-regulation of the c-Myc expression via blockade of the Tcf-4 activity after troglitazone treatment. This is the first identification of the linkage between PPAR gamma-mediated apoptosis and down-regulation of the c-myc gene expression.

Antineoplastic Agents↗
PubMed2002

Elevation of von Willebrand factor in plasma in diabetic patients with neuropathic foot ulceration.

AIMS: The present study examines the relationship between markers of endothelial dysfunction and diabetic neuropathy or consequent neuropathic foot ulceration in patients with Type 2 diabetes mellitus. METHODS: We studied 65 Type 2 diabetic patients including 25 diabetic patients without neuropathy, 27 with neuropathy but no history of foot ulceration, and 13 with neuropathic ulceration. Plasma concentrations of von Willebrand factor (vWF) and soluble thrombomodulin (TM), measures of endothelial dysfunction, were determined by enzyme immunoassays. We performed various tests quantifying aspects of diabetic neuropathy including vibration perception threshold (VPT; for sensory neuropathy), coefficient of variation of R-R intervals (CVR-R; for cardiac autonomic neuropathy), and cold-induced vasodilation in the great toe for peripheral sympathetic neuropathy. RESULTS: CVR-R and cold-induced vasodilation were significantly diminished in patients with neuropathic foot ulceration compared with patients with neuropathy but no history of foot ulceration. Plasma vWF concentrations were positively correlated with VPT and cold-induced vasodilation test, and were inversely correlated with CVR-R. Multivariate analysis disclosed that VPT and percentage vasodilation were independent factors for plasma vWF. Plasma vWF was significantly elevated in patients with foot ulceration compared with patients without neuropathy or those with neuropathy but not foot ulceration. However, plasma TM concentrations did not differ between the three groups. CONCLUSIONS: Diabetic patients with neuropathic foot ulceration had severe impairment of cardiac autonomic and peripheral sympathetic nerves. Elevation of vWF in plasma was associated with neuropathic foot ulceration, linking endothelial dysfunction to foot ulceration.

Autonomic Nervous System↗
PubMed2002

Clinical usefulness of corrected QT intervals in diabetic autonomic neuropathy in patients with type 2 diabetes.

BACKGROUND: It is recognized that QTc intervals reflect autonomic nerve function. To investigate the clinical usefulness of corrected QT intervals (QTc) in assessing autonomic nerve function in type 2 diabetes, we measured QTc intervals using Bazett's formula in 58 type 2 diabetic patients and 20 age-matched healthy subjects. METHODS: We examined relationships between QTc intervals and the coefficient of variation of RR intervals (CV(RR)), systolic blood pressure response to standing, and sympathetic skin response (SSR) whose tests reflect autonomic nerve function. We also studied the correlation between QTc and blood pressure or serum lipid concentrations. RESULTS: QTc intervals in diabetic patients were significantly longer than those in healthy subjects and showed a significant but weak negative correlation with CV(RR), as well as systolic blood pressure response to standing. No significant difference in QTc intervals was observed between patients with and without a detectable SSR. QTc intervals showed a significant positive correlation with systolic and diastolic blood pressure although it did not correlate with serum lipid concentrations. QTc also tended to be long in obese diabetic subjects (body mass index > 25). CONCLUSION: QTc intervals might also be affected by other factors such as arteriosclerotic macroangiopathy and obesity, and not only autonomic nerve function. Therefore it might be considered as an overall index for complications, and not for pure autonomic impairment.

Aged↗
PubMed2001

The JAK2 inhibitor AG490 predominantly abrogates the growth of human B-precursor leukemic cells with 11q23 translocation or Philadelphia chromosome.

The Janus kinase (JAK) family is one of intracellular protein tyrosine kinases (PTKs) present in hematopoietic and lymphoid cells and has been shown to play a crucial role in a variety of biological responses. It was reported that a human B-precursor leukemic cell line was potently inhibited in its proliferation by one of synthetic PTK inhibitors (tyrphostins), AG490, via anti-JAK2 activity. However, no extensive studies about it have been performed. In the present study, we tested 16 human lymphoid leukemic cell lines (B-precursor, 12; T cell, four) for their sensitivity to AG490 using 3H-thymidine incorporation and colony formation assays, and found that B-precursor cell lines with 11q23 translocation or Philadelphia chromosome (Ph1) whose JAK2 proved to be constitutively phosphorylated were predominantly sensitive to AG490 at a concentration that has few inhibitory effect on normal hematopoiesis. We first revealed the association of JAK2 with BCR-ABL in Ph1-positive cell lines and with Bruton's tyrosine kinase (BTK) in cell lines with 11q23 translocation by coimmunoprecipitation experiments. Of interest, AG490 markedly down-regulated phosphorylation of JAK2, but rather transiently up-regulated phosphorylation of BCR-ABL and BTK, suggesting direct implication of AG490 in the process of the JAK2 dephosphorylation. These results indicate that AG490 exerts a potent inhibitory activity to B-precursor leukemia with specific chromosomal abnormalities, and a therapeutic approach using AG490 is expected.

Antineoplastic Agents↗
PubMed2001

Changes in skin blood flow in type 2 diabetes induced by prostacyclin: association with ankle brachial index and plasma thrombomodulin levels.

In a previous study, we reported that beraprost sodium (BPS), a stable prostaglandin I(2) (PGI(2)) analog, increases skin blood flow in the feet of both control subjects and patients with type 2 diabetes, and that the flow increase induced by BPS is lower in diabetic patients than in controls. The present study was undertaken to clarify factors associated with smaller increases in skin blood flow in the feet of patients with type 2 diabetes after the administration of BPS, and to investigate the relationship between microalbuminuria and the changes in skin blood flow induced by the PGI(2) analog. We studied 61 patients with type 2 diabetes: 10 received placebo (control) and 51 (31 with normoalbuminuria and 20 with microalbuminuria) received BPS. Using laser Doppler flowmetry, we measured the skin blood flow at the pulp of the right big toe before and 90 minutes after administration of 40 microg BPS, and calculated the change in blood flow, i.e., delta flux (peak flux at 90 minutes - basal flux at 0 minutes). Plasma concentrations of soluble thrombomodulin (TM) were determined using an enzyme immunoassay (EIA) sandwich method. BPS significantly increased skin blood flow in the treatment group compared with the placebo group (P <.01). The delta flux was positively correlated with the value of the ankle brachial index (ABI) (r =.41, P <.0038) and was negatively correlated with plasma TM levels (r = -.53, P <.0001). By multiple regression analysis both the ABI value and the plasma TM level retained a significant influence on delta flux. Furthermore, both the delta flux and the ABI value in patients with microalbuminuria were lower than in patients with normoalbuminuria (P <.05). The results suggest that BPS increases the skin blood flow of the toe of patients with type 2 diabetes and that the increased flow is independently influenced by the value of the ABI and the plasma TM levels; in addition, microalbuminuria is associated with the impairment of vasodilation in the feet in response to BPS.

Adult↗
PubMed2001

Relationship between plasma soluble thrombomodulin levels and insulin resistance syndrome in type 2 diabetes: a comparison with von Willebrand factor.

Endothelial dysfunction plays a pivotal role in the initial stage of atherosclerosis. Insulin resistance is associated with accelerated atherosclerosis, especially coronary heart disease. To elucidate the relationship between endothelial dysfunction and insulin resistance or insulin resistance syndrome in patients with type 2 diabetes, we investigated the correlation between plasma soluble thrombomodulin (TM) and von Willebrand factor (vWF), measures of endothelial dysfunction, and the degree of insulin resistance evaluated by homeostasis assessment models of insulin resistance (HOMA-IR), or variables of insulin resistance syndrome. We studied 53 patients with type 2 diabetes, 23 treated with diet alone and 30 treated with sulfonylureas, who had normal renal function. The plasma soluble TM concentrations were highly correlated with HOMA-IR (r=0.64, p<0.0001), the plasma insulin (r=0.72, p<0.0001), the systolic blood pressure (r=0.45, p=0.0005), and the plasma fibrinogen (r=0.43, p=0.0018), while they were inversely correlated with the serum HDL cholesterol concentrations (r=-0.27, p=0.0344). The plasma vWF concentrations were positively correlated with HOMA-IR (r=0.35, p=0.0151) and the plasma fibrinogen (r=0.32, p=0.0203), but not with the plasma insulin, the systolic blood pressure or the HDL cholesterol concentrations. Furthermore, plasma TM, but not vWF, was positively correlated with total number of variables of insulin resistance syndrome (r=0.45, p=0.0005). These results indicate that endothelial dysfunction may be associated with the pathogenesis of insulin resistance syndrome as well as insulin resistance, and that the plasma TM might reflect endothelial damage better than the plasma vWF in the state of insulin resistance in patients with type 2 diabetes.

Adult↗
PubMed2001

Clinical features of a polymorphism of the beta3-adrenergic receptor gene in patients with type 2 diabetes mellitus--a study using a pin-point sequencing method.

UNLABELLED: The human beta(3)-adrenergic receptor (beta(3)AR) is expressed specifically in adipose tissues, and its activation is activated in brown adipose tissues during thermogenesis and in white adipose tissues during lipolysis. We investigated the relationship between a polymorphism of the beta(3)AR gene and the clinical features of type 2 diabetes mellitus. Studies were conducted in 30 type 2 diabetic patients (15 males and 15 females). Analysis of polymorphisms of the beta(3)AR gene was performed by a pin-point sequencing method using the hair of the subjects. Preperitoneal (P-fat) and subcutaneous fat (S-fat) levels were determined by ultrasonography. We found a Trp(64)Arg allele of the beta(3)AR gene in the hair of 27% of all patients. The patients with this mutation showed a significantly younger onset-age of diabetes than those of the wild type. The body mass index, serum GPT levels, fasting immunoreactive insulin (IRI) and daily urinary C-peptide reaction (CPR) in the mutation group were markedly higher than in the wild type group. The P-fat, serum cholesterol and leptin concentrations tended to be higher in the mutation group. Patients in the mutation group had a significantly higher prevalence of hypertension (80%) compared with those in the wild type group (20%). CONCLUSIONS: The present results suggest that the clinical features of diabetic patients with a missense mutation in the beta(3)AR gene are substantially distinct from those of the wild type patients. These specific features include obesity, hyperinsulinemia, hypertension, and an increase in preperitoneal fat.

Adipose Tissue↗
PubMed2001

The E2A-HLF oncoprotein activates Groucho-related genes and suppresses Runx1.

The E2A-HLF fusion gene, formed by the t(17;19)(q22;p13) chromosomal translocation in leukemic pro-B cells, encodes a chimeric transcription factor consisting of the transactivation domain of E2A linked to the bZIP DNA-binding and protein dimerization domain of hepatic leukemia factor (HLF). This oncoprotein blocks apoptosis induced by growth factor deprivation or irradiation, but the mechanism for this effect remains unclear. We therefore performed representational difference analysis (RDA) to identify downstream genetic targets of E2A-HLF, using a murine FL5.12 pro-B cell line that had been stably transfected with E2A-HLF cDNA under the control of a zinc-regulated metallothionein promoter. Two RDA clones, designated RDA1 and RDA3, were differentially upregulated in E2A-HLF-positive cells after zinc induction. The corresponding cDNAs encoded two WD40 repeat-containing proteins, Grg2 and Grg6. Both are related to the Drosophila protein Groucho, a transcriptional corepressor that lacks DNA-binding activity on its own but can act in concert with other proteins to regulate embryologic development of the fly. Expression of both Grg2 and Grg6 was upregulated 10- to 50-fold by E2A-HLF. Immunoblot analysis detected increased amounts of two additional Groucho-related proteins, Grg1 and Grg4, in cells expressing E2A-HLF. A mutant E2A-HLF protein with a disabled DNA-binding region also mediated pro-B cell survival and activated Groucho-related genes. Among the transcription factors known to interact with Groucho-related protein, only RUNX1 was appreciably downregulated by E2A-HLF. Our results identify a highly conserved family of transcriptional corepressors that are activated by E2A-HLF, and they suggest that downregulation of RUNX1 may contribute to E2A-HLF-mediated leukemogenesis.

Amino Acid Sequence↗
PubMed2001

Downregulation of Bim, a proapoptotic relative of Bcl-2, is a pivotal step in cytokine-initiated survival signaling in murine hematopoietic progenitors.

Two distinct signaling pathways regulate the survival of interleukin-3 (IL-3)-dependent hematopoietic progenitors. One originates from the membrane-proximal portion of the cytoplasmic domain of the IL-3 receptor (betac chain), which is shared by IL-3 and granulocyte-macrophage colony-stimulating factor and is involved in the regulation of Bcl-x(L) through activation of STAT5. The other pathway emanates from the distal region of the betac chain and overlaps with downstream signals from constitutively active Ras proteins. Although the latter pathway is indispensable for cell survival, its downstream targets remain largely undefined. Here we show that the expression of Bim, a member of the BH3-only subfamily of cell death activators, is downregulated by IL-3 signaling through either of two major Ras pathways: Raf/mitogen-activated protein kinase and the phosphatidylinositol 3-kinase/mammalian target of rapamycin. Akt/phosphokinase B does not appear to play a significant role in this regulatory cascade. Bim downregulation has important implications for cell survival, since enforced expression of this death activator at levels equivalent to those induced by cytokine withdrawal led to apoptosis even in the presence of IL-3. We conclude that Bim is a pivotal molecule in cytokine regulation of hematopoietic cell survival.

Animals↗
PubMed2001

Brain natriuretic polypeptide in type 2 NIDDM patients with albuminuria.

We investigated plasma brain natriuretic polypeptide (BNP) in Type 2 NIDDM patients with albuminuria. This study involved normal control subjects (Controls), hypertensive patients without diabetes mellitus (HT) and Type 2 NIDDM patients. Diabetic patients were divided into 4 groups by urinary albumin index (Alb-I): group I <30; group II 30-149; group III 150-300; group IV >300 mg/g creatinine. BNP levels in group III or IV were significantly higher than in Controls. The diabetic patients were re-divided into 4 groups (DM: with neither diabetic retinopathy (which was one of indicators of microangiopathy) nor hypertension, DM+HT: without diabetic retinopathy and with hypertension, DM+R: with diabetic retinopathy and without hypertension and DM+R+HT: with both diabetic retinopathy and hypertension). The Alb-I levels in DM+HT and DM+R+HT were significantly higher than the Controls, indicating the development of diabetic nephropathy in those groups. BNP levels in DM+HT, DM+R or DM+R+HT were significantly higher than in Controls. This indicates that BNP levels elevate in diabetic patients with increased albuminuria due to hypertension or microangiopathy deteriorating diabetic nephropathy. Elevated plasm BNP may play a pathophysiological role in the development of diabetic nephropathy.

Albuminuria↗
PubMed2001

[Cord blood transplantation with two mismatched HLA loci in a child with acute lymphoblastic leukemia in second remission: follow-up of minimal residual disease using a clone-specific probe].

A 9-year-old girl with acute lymphoblastic leukemia in second remission underwent cord blood transplantation (CBT) from an HLA-mismatched (2 loci by serotype, 3 loci by genotype) unrelated donor. The infused nucleated cell count was 1.95 x 10(7)/kg. FK506 and mini-MTX were used to prevent graft-versus-host disease (GVHD), but grade II acute GVHD developed on the skin (stage III). The GVHD subsided after administration of corticosteroid, but marked hyperglycemia developed, which required transient insulin therapy for its control. Minimal residual disease (MRD) was assessed using a clone-specific probe for the JH region. MRD was positive before CBT, but became negative one month after CBT. Now, at 14 months after CBT, the patient is in a disease-free state without detectable MRD. These observations suggest that CBT with two mismatched HLA loci can be performed safely, and that sequential analysis of MRD is useful for evaluation of the disease status after CBT.

Blood Donors↗
PubMed2001

[Transient myelodysplasia associated with human parvovirus B19 infection in a child without underlying disease].

Human parvovirus B19 (HPV-B19) infection is known to frequently induce aplastic crisis in patients with hemolytic anemia, but rarely causes hematological disorders in healthy subjects. We report a 5-year-old boy who showed transient myelodysplasia associated with HPV-B19 infection. He was admitted with severe nasal bleeding, and laboratory data showed marked thrombocytopenia (1,000/microliter), anemia (Hb: 8.4 g/dl), and mild leukopenia (3,000/microliter). A bone marrow smear revealed myelodysplastic changes in three cell lineages, but no giant proerythroblasts or megakaryocytes. The pancytopenia and myelodysplastic changes were resolved spontaneously within a week without any medication other than transfusion of red blood cells and platelets. Serological examination revealed an elevation of IgG antibody against HPV-B19 on days 15 and 120 and its subsequent decrease thereafter, although HPV-B19-specific DNA was not detected in the serum at onset. The clinical course and laboratory data suggest an etiologic role of HPV-B19 infection in the occurrence of transient myelodysplasia.

Child, Preschool↗
PubMed2000

Serum concentrations of advanced glycation endproducts are associated with the development of atherosclerosis as well as diabetic microangiopathy in patients with type 2 diabetes.

We measured serum concentrations of advanced glycation endproducts (AGEs) in patients with type 2 diabetes, to elucidate the mechanisms underlying the elevated serum concentrations of AGEs and to clarify the relationship between serum AGE concentrations and the development of microangiopathy and macroangiopathy. Serum AGEs were significantly higher in diabetic patients than in age-matched control subjects (p < 0.0001). In diabetic patients, serum AGEs were positively correlated with HbAlc (r = 0.47, p < 0.0001), urinary albumin excretion (UAE) (r = 0.42, p < 0.0001), diabetes duration (r = 0.31, p = 0.0030), and fasting plasma glucose (r = 0.34, p = 0.0010). Multiple regression analysis disclosed that only the HbAlc and UAE levels independently correlated with serum AGE levels. Serum AGEs in diabetic patients with progressive retinopathy and overt nephropathy were significantly higher than in those with less severe retinopathy and nephropathy. Serum AGEs were significantly higher in the diabetic patients with coronary heart disease (CHD) than in those without CHD. These results suggest that the HbAlc and UAE levels are independent risk factors for increased serum AGE concentrations in type 2 diabetic patients, and that higher serum AGE concentrations are associated with increased severity of diabetic retinopathy and nephropathy. Serum AGE concentrations may be a useful marker not only for the severity of diabetic microangiopathy but also for the development of CHD in patients with type 2 diabetes mellitus.

Aged↗
PubMed2000

Relationship between soluble thrombomodulin in plasma and coagulation or fibrinolysis in type 2 diabetes.

Serum concentration of soluble thrombomodulin (TM) is thought to be a marker for endothelial damage. Although several studies have reported that serum TM concentrations are increased in patients with diabetes mellitus, there is little information on the physiological function of soluble TM in human plasma. To evaluate the relationship of soluble TM in plasma between coagulation and/or fibrinolysis system in patients with diabetes, we measured plasma soluble TM, protein C activity (a natural anticoagulant induced by thrombin-TM complex), prothrombin F1+2 (a direct marker of thrombin generation), and plasmin-alpha 2-antiplasmin complex (PAP) and D dimer (measures of fibrinolytic activity) in 55 patients with type 2 diabetes mellitus. The plasma concentrations of soluble TM (P<0.01), protein C activity (P<0.01), prothrombin F1+2 (P<0.05), PAP (P<0.001) and D dimer (P<0.001) were significantly higher in the diabetic patients than the 48 age-matched control subjects. The plasma concentrations of TM and PAP were obviously increased in patients with diabetic nephropathy. In the diabetic patients, the plasma concentrations of soluble TM were inversely correlated with the protein C activity (r=-0.43, P<0.005), and were positively correlated with the plasma concentrations of prothrombin F1+2 (r=0.63, P<0.0001) and the plasma PAP concentrations (r=0.30, P<0.05). The present study demonstrated that both coagulation and fibrinolysis are enhanced concomitantly in patients with type 2 diabetes mellitus, and that an increase in plasma concentration of soluble TM is associated not only with hypercoagulability but also with enhanced fibrinolysis in diabetic patients.

Adult↗
PubMed2000

Serum levels of carboxy-terminal propeptide of human type I procollagen are an indicator for the progression of diabetic nephropathy in patients with type 2 diabetes mellitus.

The finding that glomerular mesangial cells produce human type I collagen suggests that the serum levels of carboxy-terminal propeptide of human type I procollagen (P1CP) may reflect the severity of diabetic nephropathy. We therefore investigated the relationship between serum P1CP levels and the extent of diabetic complications in 100 patients (46 males and 54 females) with Type 2 diabetes and in 64 healthy subjects. Serum P1CP was determined by radioimmunoassay. In diabetes, we defined P1CP levels less than 142 ng/ml as a normal P1CP group (group A), whereas we defined them as equal to or greater than 142 ng/ml as a high P1CP group (group B). The diabetic patients had significantly elevated serum P1CP levels compared with the controls. The prevalence of hypertension, proliferative diabetic retinopathy or macroalbuminuria was significantly higher in group B than in group A. Serum P1CP levels showed a significant positive correlation with urinary albumin excretion, but not with fasting blood glucose, glycosylated hemoglobin A(1c) or serum osteocalcin. Macroalbuminuric patients showed significantly higher P1CP levels than the normoalbuminuric patients. In patients in the absence of diabetic nephropathy, no significant differences of P1CP levels were found among the severity of diabetic retinopathy. The present results suggest that serum P1CP levels reflect the progression of diabetic nephropathy in patients with Type 2 diabetes.

Biomarkers↗
PubMed2000

Participation of granulocyte colony-stimulating factor in the growth regulation of leukemia cells from Philadelphia chromosome-positive acute leukemia and blast crisis of chronic myeloid leukemia.

Granulocyte colony-stimulating factor (G-CSF) has been shown to support the growth of multipotential hematopoietic stem cells in addition to the cells of neutrophilic lineage. Philadelphia chromosome (Ph1)-positive leukemia has its origin in the hematopoietic stem cell. In the present study, we demonstrated that the proliferation of leukemic cells from chronic myeloid leukemia in blast crisis (CML-BC) and Ph1-positive acute lymphoblastic leukemia (ALL) cases is frequently stimulated with G-CSF in vitro. We next studied a total of 12 leukemic cell lines established from CML-BC (n= 6) and Ph1-positive acute leukemia (n= 6): four 'myeloid', five 'biphenotypic', and three 'lymphoid' types. All cell lines expressed G-CSF receptor (G-CSFR) in flow cytometric analysis, but their proliferative response to G-CSF in 3H-thymidine incorporation assay varied. The 'biphenotypic' cell lines expressed G-CSFR at higher levels and showed the most pronounced response to G-CSF. The 'lymphoid' cell lines showed intermediate G-CSFR expression with the modest response to G-CSF. Unexpectedly, 'myeloid' cell lines showed lower G-CSFR expression and lower G-CSF response compared with 'biphenotypic' cell lines. In three of four 'myeloid' cell lines, proliferation was partially inhibited by an addition of anti-G-CSF neutralizing monoclonal antibody into culture medium. Further, the % inhibition of 3H-thymidine uptake of cell lines positively correlated with the amount of their intracellular G-CSF measured by enzyme immunoassay, suggesting an autocrine growth mechanism via the G-CSF/G-CSFR interaction. These results suggest that G-CSF play an important role in the growth regulation of leukemia cells from Ph1-positive acute leukemia and CML-BC.

Blast Crisis↗