Ultrasound-guided supraclavicular brachial plexus block in upper limb surgery: outcomes and patient satisfaction.

We examined the outcomes and levels of patient satisfaction in 202 consecutive cases of ultrasound-guided supraclavicular brachial plexus block (SBPB) in upper limb surgery performed between September 2007 and March 2010. All blocks were performed by orthopaedic surgeons using ultrasound visualisation with a high-frequency linear probe. The probe was placed in the coronal-oblique plane in the supraclavicular fossa, and the puncture was 'in-plane' from lateral to medial. Most of the blocks were performed with 0.75% ropivacaine/1% lidocaine (1:1), with or without adrenaline in 1:200 000 dilution. In 201 patients (99.5%) the brachial plexus block permitted surgery without conversion to general anaesthesia. The mean procedure time for block was 3.9 min (2 to 12), the mean waiting time for surgery was 34.1 min (10 to 64), the mean surgical time was 75.2 min (6 to 232), and the mean duration of post-anaesthetic analgesia was 437 min (171 to 992). A total of 20 patients (10%) developed a transient Horner's syndrome. No nerve injury, pneumothorax, arterial puncture or systemic anaesthetic toxicity were recorded. Most patients (96.7%) were satisfied with ultrasound-guided SBPB. This study demonstrates the efficacy and safety of ultrasound-guided SBPB for orthopaedic surgery on the upper limb.

Inhibition of the CXCR3-mediated pathway suppresses ultraviolet B-induced pigmentation and erythema in skin.

BACKGROUND: Skin pigmentation by ultraviolet (UV) B radiation is caused in part by inflammation mediated by chemokines and cytokines secreted by keratinocytes in the irradiated area. However, such inflammatory processes have not been well documented. OBJECTIVES: To elucidate the inflammation processes caused by UVB irradiation using skin-lightening agents that suppress melanin synthesis after UVB irradiation. METHODS: Utilizing a three-dimensional (3D) skin model, agents that suppressed formation of sunburn cells (SBC) after UVB irradiation were screened. Molecules whose expression was upregulated by UVB irradiation and attenuated by pretreatment with the agent were then screened by gene microarray to explore the mechanism of UVB irradiation. Messenger RNA expression of the molecules identified to be responsible for melanin biosynthesis was knocked down with a Tet-off shRNA lentivirus construct to confirm the involvement of the molecule in the pigmentation pathway following UVB irradiation. RESULTS: Paeonia suffruticosa Andrews (PSA) pretreatment suppressed SBC formation in the 3D skin model, and erythema formation and pigmentation in volunteers exposed to UVB irradiation. Comprehensive gene analysis after UVB irradiation showed upregulation of CXCR3 and its ligands, CXCL9/monokine induced by interferon (IFN)-γ (MIG), CXCL10/10-kDa IFN-γ-induced protein (IP-10) and CXCL11/inducible T-cell α-chemoattractant (I-TAC). Upregulation of these genes was partially suppressed by PSA pretreatment. Melanin biosynthesis increased upon stimulation of CXCR3 ligands (MIG, IP-10 or I-TAC) and decreased following CXCR3 downregulation by shRNA knockdown. CONCLUSIONS: UVB irradiation activates CXCR3-mediated signalling that leads to melanin synthesis. PSA pretreatment shows a lightening effect partly by attenuating CXCR3-mediated signalling at the transcriptional level.

One-dimensional quantitative evaluation of peripheral lung adenocarcinoma with or without ground-glass opacity on thin-section CT images using profile curves.

The purpose of our investigation was to compare the usefulness of the subjective visual assessment of ground-glass opacity (GGO) with a quantitative method that used a profile curve to determine prognosis. 96 adenocarcinomas were studied. Three diameters ([D1]-[D3]) were defined for estimating the diameter of tumours on the monitor: the distance between two points was measured using software that displays a CT density profile across the tumour. One experienced and one less experienced radiologist independently evaluated the following six parameters: the three diameters [D1]-[D3]; the solid portion of total tumour in the two different ratios ([D2]/[D1], [D3]/[D1]); and the area ratio of GGO for total opacity to subjective visual evaluation. Interobserver agreement between the two radiologists of the diameters (mean bias+/- 1.96 standard deviations) was as follows: [D1], -0.7 +/- 6 mm; [D2], 0.4 +/- 4.4 mm; and [D3], -0.1 +/- 4.2 mm (Bland and Altman's method). Interobserver agreement was fair in evaluating the area ratio of GGO (kappa test, kappa = 0.309). Univariate logistic regression analysis revealed that two ratios ([D2]/[D1], [D3]/[D1]) might be significantly useful in estimating lymph node metastasis (p < 0.026), lymph duct invasion (p < 0.001) and recurrence (p < 0.015). Observation of the area ratio of GGO by an experienced radiologist would be necessary for estimating lymph node metastasis (p = 0.04) and lymph duct invasion (p < 0.001). We concluded that the ratio of solid component to total tumour, which is obtainable in a more objective and simple way using profile curves obtained by software, is a more useful method of estimating prognosis than is visual assessment.

Expression of myeloperoxidase enhances the chemosensitivity of leukemia cells through the generation of reactive oxygen species and the nitration of protein.

Myeloperoxidase (MPO), a pivotal lineage marker for acute myeloid leukemia (AML), has been also shown to have a prognostic value: a high percentage of MPO-positive blasts correlates to favorable prognosis. To understand the relationship between the expression of MPO in leukemia cells and the response to chemotherapeutic agents, we established MPO-expressing K562 leukemia cell lines and then treated them with cytosine arabinocide (AraC). Cells expressing wild-type MPO, but not mutant MPO that could not mature, died earlier of apoptosis than control K562 cells. Reactive oxygen species (ROS) were generated more in leukemia cells expressing MPO, and the generation was abrogated by MPO inhibitors or antioxidants. Tyrosine nitration of cellular protein also increased more in MPO-expressing K562 cells than control cells after treatment with AraC. In clinical samples, CD34-positive AML cells from high-MPO cases showed a tendency to be sensitive to AraC in the colony-formation assay, and the generation of ROS and the nitration of protein were observed only when the percentage of MPO-expressing cells was high. These data suggest that MPO enhances the chemosensitivity of AML through the generation of ROS and the nitration of proteins.

Description of International Caenorhabditis elegans Experiment first flight (ICE-FIRST).

Traveling, living and working in space is now a reality. The number of people and length of time in space is increasing. With new horizons for exploration it becomes more important to fully understand and provide countermeasures to the effects of the space environment on the human body. In addition, space provides a unique laboratory to study how life and physiologic functions adapt from the cellular level to that of the entire organism. Caenorhabditis elegans is a genetic model organism used to study physiology on Earth. Here we provide a description of the rationale, design, methods, and space culture validation of the ICE-FIRST payload, which engaged C. elegans researchers from four nations. Here we also show C. elegans growth and development proceeds essentially normally in a chemically defined liquid medium on board the International Space Station (10.9 day round trip). By setting flight constraints first and bringing together established C. elegans researchers second, we were able to use minimal stowage space to successfully return a total of 53 independent samples, each containing more than a hundred individual animals, to investigators within one year of experiment concept. We believe that in the future, bringing together individuals with knowledge of flight experiment operations, flight hardware, space biology, and genetic model organisms should yield similarly successful payloads.

Checkpoint and physiological apoptosis in germ cells proceeds normally in spaceflown Caenorhabditis elegans.

It is important for human life in space to study the effects of environmental factors during spaceflight on a number of physiological phenomena. Apoptosis plays important roles in development and tissue homeostasis in metazoans. In this study, we have analyzed apoptotic activity in germ cells of the nematode C. elegans, following spaceflight. Comparison of the number of cell corpses in wild type or ced-1 mutants, grown under either ground or spaceflight conditions, showed that both pachytene-checkpoint apoptosis and physiological apoptosis in germ cells occurred normally under spaceflight conditions. In addition, the expression levels of the checkpoint and apoptosis related genes are comparable between spaceflight and ground conditions. This is the first report documenting the occurrence of checkpoint apoptosis in the space environment and suggests that metazoans, including humans, would be able to eliminate cells that have failed to repair DNA lesions introduced by cosmic radiation during spaceflight.

Night-time restricted feeding normalises clock genes and Pai-1 gene expression in the db/db mouse liver.

AIMS/HYPOTHESIS: An increase in PAI-1 activity is thought to be a key factor underlying myocardial infarction. Mouse Pai-1 (mPai-1) activity shows a daily rhythm in vivo, and its transcription seems to be controlled not only by clock genes but also by humoral factors such as insulin and triglycerides. Thus, we investigated daily clock genes and mPai-1 mRNA expression in the liver of db/db mice exhibiting high levels of glucose, insulin and triglycerides. METHODS: Locomotor activity was measured using an infrared detection system. RT-PCR or in situ hybridisation methods were applied to measure gene expression. Humoral factors were measured using measurement kits. RESULTS: The db/ db mice showed attenuated locomotor activity rhythms. The rhythmic expression of mPer2 mRNA was severely diminished and the phase of mBmal1 oscillation was advanced in the db/db mouse liver, whereas mPai-1 mRNA was highly and constitutively expressed. Night-time restricted feeding led to a recovery not only from the diminished locomotor activity, but also from the diminished Per2 and advanced mBmal1 mRNA rhythms. Expression of mPai-1 mRNA in db/db mice was reduced to levels far below normal. Pioglitazone treatment slightly normalised glucose and insulin levels, with a slight reduction in mPai-1 gene expression. CONCLUSIONS/INTERPRETATION: We demonstrated that Type 2 diabetes impairs the oscillation of the peripheral oscillator. Night-time restricted feeding rather than pioglitazone injection led to a recovery from the diminished locomotor activity, and altered oscillation of the peripheral clock and mPai-1 mRNA rhythm. Thus, we conclude that scheduled restricted food intake may be a useful form of treatment for diabetes.

The percentage of myeloperoxidase-positive blast cells is a strong independent prognostic factor in acute myeloid leukemia, even in the patients with normal karyotype.

To examine whether the percentage of myeloperoxidase (MPO)-positive blast cells is useful as a prognostic factor for acute myeloid leukemia (AML), cytochemical analysis of MPO was performed in 491 patients who were registered to the Japan Adult Leukemia Study Group-AML92 study. Patients were divided into two using the percentage of MPO-positive blast (high [>or=50%] and low (<50%)). Complete remission rates were 85.4% in the former and 64.1% in the latter (P=0.001). The overall survival (OS) and the disease-free survival (DFS) were significantly better in the high MPO group (48.3 vs 18.7% for OS, and 36.3 vs 20.1% for DFS, P<0.001, respectively). Multivariate analysis showed that both karyotype and the percentage of MPO-positive blast cells were equally important prognostic factors. The high MPO group still showed a better survival even when restricted to the intermediate chromosomal risk group or the patients with normal karyotype (P<0.001). The OS of patients with normal karyotype in the high MPO group was almost equal with that of the favorable chromosomal risk group. The percentage of MPO-positive blast cells is a simple and highly significant prognostic factor for AML patients, and especially useful to stratify patients with normal karyotype.

Localization of bone morphogenetic protein-2 in human osteoarthritic cartilage and osteophyte.

OBJECTIVES: To examine the localization of bone morphogenetic protein (BMP)-2 mRNA and protein in human osteoarthritic (OA) articular cartilage and osteophyte. DESIGN: Five normal, four growing and 14 OA human cartilage samples, graded histomorphologically by Mankin Score, were studied by in situ hybridization and immunohistochemistry for the expression of BMP-2. RESULTS: BMP-2 mRNA was present in chondrocytes in neonatal growing articular cartilage, but was scarcely present in normal adult articular cartilage. In OA articular cartilage, BMP-2 mRNA and protein were detected in both clustering and individual chondrocytes in moderately or severely damaged OA cartilage. In moderately damaged OA cartilage, BMP-2 mRNA was localized in both upper and middle zone chondrocytes, but was not detected in deep layer chondrocytes. In severely damaged OA cartilage, cellular localization of BMP-2 mRNA was extended to the deep zone. In the area of osteophyte formation, BMP-2 mRNA was intensely localized in fibroblastic mesenchymal cells, fibrochondrocytes, chondrocytes and osteoblasts in newly formed osteophytic tissue. The pattern of BMP-2/4 immunolocalization was associated with that of mRNA localization. CONCLUSIONS: BMP-2 mRNA and BMP-2/4 were detected in cells appearing in OA tissues. BMP-2 was localized in cells of degenerating cartilage as well as osteophytic tissue. Given the negative localization of BMP-2 in normal adult articular cartilage, BMP-2 might be involved in the regenerating and anabolic activities of OA cells, which respond to cartilage damage occurring in osteoarthritis.

Expression and distribution of transcripts for sonic hedgehog in the early phase of fracture repair.

Localization and expression of mRNAs for sonic hedgehog (Shh) at a fracture site in the early phase postfracture were investigated by in situ hybridization and reverse transcription and polymerase chain reaction (RT-PCR). A closed fracture was made in the midshaft of the right tibia of 5-week-old ICR mice, and fractured sites were harvested prefracture (day 0) and on days 2 and 12. In situ hybridization revealed that transcripts for Shh were not detected on day 0, but they were detected in proliferating callus-forming cells in the periosteum and the surrounding tissue, and in the medullary cavity prior to apparent new cartilage and bone formation. Gli 1 (a signaling mediator for Shh) and bone morphogenetic protein-4 transcripts were colocalized with those for Shh transcripts on day 2. The RT-PCR showed that Shh mRNA was detected in the PCR product from day 2, but not from days 0 and 12. These findings are the first description about the activation of Shh gene in the early postfracture reaction.

Vitamin E ointment at high dose levels suppresses contact dermatitis in rats by stabilizing keratinocytes.

OBJECTIVE: The pharmacological effect of vitamin E ointment at high dose levels was investigated in rats and mice during the development of contact dermatitis. MATERIALS AND METHODS: Allergic or irritant contact dermatitis was induced in sensitized or unsensitized animals by topical application of chemical agent(s). Cultured keratinocytes were prepared from dorsal skin of rats. RESULTS: The vitamin E ointment at 20-40% suppressed allergic and irritant contact dermatitis, exerting a comparable effect to that of 0.5% prednisolone ointment. Microscopic findings revealed that 20% vitamin E ointment reduced the keratinocyte damage, whereas 0.5% prednisolone was ineffective. The protective action of vitamin E on keratinocyte damage was also confirmed in a cell culture experiment. Furthermore, 20% vitamin E ointment blocked down-regulation of skin barrier function induced by contact dermatitis, although 0.5% prednisolone ointment was inactive. CONCLUSIONS: These results indicate that 20% vitamin E ointment suppresses contact dermatitis by stabilizing keratinocytes, concomitantly with novel, interesting properties.

Epstein-Barr virus-associated T-lymphoproliferative disease with hemophagocytic syndrome, followed by fatal intestinal B lymphoma in a young adult female with WHIM syndrome. Warts, hypogammaglobulinemia, infections, and myelokathexis.

A rare association of Epstein-Barr virus-associated T- and B-lymphoproliferative disease (EBV(+) T- and EBV(+) B-LPD) in a patient with WHIM (warts, hypogammaglobulinemia, infections, and myelokathexis) syndrome is reported. A 26-year-old Japanese female, who had been treated for WHIM syndrome since early childhood, developed hemophagocytic syndrome associated with EBV(+) T-LPD at the lymph nodes and spleen. The disease rapidly resolved in response to prednisolone therapy. However, 6 weeks later, fatal EBV(+) B lymphoma unresponsive to chemotherapy occurred in the intestine and other organs. Caution must be exercised that the patient with WHIM syndrome may be at risk for EBV-LPD.

Induction therapy by frequent administration of doxorubicin with four other drugs, followed by intensive consolidation and maintenance therapy for adult acute lymphoblastic leukemia: the JALSG-ALL93 study.

In order to improve the disappointing prognosis of adult patients with acute lymphoblastic leukemia (ALL), we applied similar induction therapy as that used for acute myeloid leukemia (AML), ie frequent administration of doxorubicin (DOX). DOX 30 mg/m(2) was administered from days 1 to 3 and from days 8 to 10 together with vincristine, prednisolone, cyclophosphamide and L-asparaginase, followed by three courses of consolidation and four courses of intensification. From December 1993 to February 1997, 285 untreated adult patients with de novo ALL were entered. Of 263 evaluable patients (age 15 to 59; median 31), 205 (78%) obtained complete remission (CR). At a median follow-up period of 63 months, the predicted 6-year overall survival (OS) rate of all patients was 33%, and disease-free survival (DFS) rate of CR patients was 30%, respectively. By multivariate analysis, favorable prognostic factors for the achievement of CR were age <40 and WBC <50 000/microl; for longer OS were age <30 and WBC <30 000/microl; and for longer DFS of CR patients were FAB L1 and ALT <50 IU/l. Among 229 patients who had adequate cytogenetic data, 51 (22%) had Philadelphia (Ph) chromosome. Ph-negative chromosome was a common favorable prognostic factor for CR, longer OS and DFS. DFS was not different between early sequential intensification (n = 48) and intermittent intensification (n = 43) during the maintenance phase. Among CR patients under 40 years old, the 6-year survival was not different between the allocated related allo-BMT group (34 patients) and the allocated chemotherapy group (108 patients). However, among patients with Ph-positive ALL, the survival of patients who actually received allo-BMT was superior to that of patients who received chemotherapy (P = 0.046).

Prognostic significance of the null genotype of glutathione S-transferase-T1 in patients with acute myeloid leukemia: increased early death after chemotherapy.

We investigated the prognostic significance of genetic polymorphism in glutathione-S transferase mu 1 (GSTM1), glutathione-S transferase theta 1 (GSTT1), NAD(P)H:quinone oxidoreductase (NQO1) and myeloperoxidase (MPO), the products of which are associated with drug metabolism as well as with detoxication, in 193 patients with de novo acute myeloid leukemia (AML) other than M3. Of the patients, 64.2% were either homozygous or heterozygous for GSTT1 (GSTT1(+)), while 35.8% showed homozygous deletions of GSTT1 (GSTT1(-)). The GSTT1(-) group had a worse prognosis than the GSTT1(+) group (P = 0.04), whereas other genotypes did not affect the outcome. Multivariate analysis revealed that GSTT1(-) was an independent prognostic factor for overall survival (relative risk: 1.53; P = 0.026) but not for disease-free survival of 140 patients who achieved complete remission (CR). The rate of early death after the initiation of chemotherapy was higher in the GSTT1(-) group than the GSTT1(+) group (within 45 days after initial chemotherapy, P = 0.073; within 120 days, P = 0.028), whereas CR rates and relapse frequencies were similar. The null genotype of GSTT1 might be associated with increased toxicity after chemotherapy.

Developmental changes in PSD-95 and Narp mRNAs in the rat olfactory bulb.

Glutamate is the main neurotransmitter in the olfactory bulb. Recently, postsynaptic-density 95 (PSD-95) and neuronal activity-regulated pentraxin (Narp) have been reported to be pivotal for targeting and clustering of NMDA receptors and AMPA receptors, respectively. We thus investigated the expressions of PSD-95 and Narp mRNAs in the rat developing olfactory bulb. PSD-95 mRNA was already expressed in most neurons on the first postnatal day (P1). On the other hand, Narp mRNA expression was weakly seen only in mitral cells on P1. Thereafter, we found initial expression of Narp mRNA on P7 in periglomerular cells, and on P14 in granular cells, indicating that in the developing olfactory bulb PSD-95 mRNA expression precedes Narp mRNA expression, and that the expression pattern of Narp mRNA seems to be well correlated with the maturation of the neurons. These results indicate that PSD-95 and Narp play important roles in making efficient excitatory synapses in the developing rat olfactory bulb, and suggest that olfactory neurons might first express PSD-95 for making efficient NMDA receptors and thereafter express Narp for efficient AMPA receptors.

Developmental changes in gephyrin and collybistin mRNA expressions in the rat olfactory bulb.

GABA and glycine are inhibitory neurotransmitters in the olfactory bulb. Recently, gephyrin, a receptor-associated peripheral membrane protein, and collybistin, a gephyrin-binding protein have been shown to be pivotal for the formation of postsynaptic glycine and GABA(A) receptor clusters. In this study, we, thus, examined expressions of gephyrin and collybistin mRNAs in the developing olfactory bulb using in situ hybridization. Although collybistin has two splice variants, we found only collybistin 1 isoform mRNA in the developing olfactory bulb. On the first postnatal day (P1), mitral cells abundantly expressed gephyrin and collybistin 1 mRNAs. However, their expressions were weak or not detected in the other regions. On P3, we first detected both transcripts in granule cells. It was on P7 when periglomerular cells first showed hybridization signals for gephyrin and collybistin mRNAs. The sequence of their expressions was well correlated with that of the maturation of individual neurons, suggesting that gephyrin and collybistin 1 mRNA expressions are induced when neurons arrive at their final destinations and ready for synaptogenesis, and that they are indispensable to make efficient inhibitory synapses in the developing rat olfactory bulb.

[Acute myeloid leukemia].

Acute myeloid leukemia (AML) has been treated with combination chemotherapy, hematopoietic stem cell transplantation (HSCT) and differentiation induction therapy. Intensive induction and consolidation therapy including high dose cytarabine (HDAC) is a widely used combination in chemotherapy in the USA and European countries. In Japan, the efficacy of HDAC needs to be evaluated under a good clinical trial. Stem cell source for HSCT has been expanded, and the number of peripheral blood stem cell transplantations is greater than that of bone marrow transplantation, especially for auto-transplantation. Despite some randomized clinical trials, we still do not know whether HSCT provides longer survival than chemotherapy for patients with AML when performed during their first remission. Differentiation therapy for acute promyelocytic leukemia (APL) using ATRA showed clear success in the treatment for AML. APL is stratified with its specific karyotype and morphology, and this stratification leads to the improvement of overall survival of patients with APL. Several clinical study groups in the world have studied prognostic factors and it has been shown that the chromosomal abnormality of AML cells is closely related to the response to the chemotherapy. The stratification of AML using these prognostic factors is incorporated in some clinical trials to determine whether this approach actually leads to better survival for patients with AML.

Multicenter prospective study of interferon-alpha versus bone marrow transplantation for newly diagnosed patients with chronic myelogenous leukemia: a preliminary analysis.

Interferon-alpha (IFN-alpha) therapy was compared with bone marrow transplantation (BMT) in patients with chronic myelogenous leukemia (CML) in a multicenter, prospective study. Of 254 evaluable patients, 175 received IFN-alpha and 79 received allogeneic BMT, 50 of whom received transplants from human leukocyte antigen (HLA)-identical related donors and 29 from HLA-matched unrelated donors. Complete hematologic response was achieved by 148 patients (89%) in the IFN-alpha group and 53 (78%) in the BMT group. In the IFN-alpha group, a complete cytogenetic response was induced in 25 patients (15%), a partial cytogenetic response in 37 (23%), and a minor cytogenetic response in 41 (25%). At a median follow-up of 38 months, in the IFN-alpha group the predicted 5-year survival rate was 79%, and the predicted 5-year rate of remaining in chronic phase was 66%. In the BMT group the predicted 5-year survival rate was 72% for related-donor BMT and 67% for unrelated-donor BMT. Among low Sokal-risk patients, 5-year survival did not differ between IFN-alpha therapy and BMT, irrespective of age. In higher Sokal-risk patients, survival for related-donor BMT and unrelated-donor BMT tended to be better than that with IFN-alpha therapy in younger patients. On the other hand, in older patients, survival in the BMT group, especially for those receiving unrelated-donor BMT, appeared to be inferior to that in the IFN-alpha group. Unrelated-donor BMT can be recommended for high-risk younger patients. However, for older patients, it should be performed after careful consideration of prognostic factors such as age, Sokal score, and response to IFN-alpha.

Analysis of prognostic factors in newly diagnosed patients with acute promyelocytic leukemia: the APL92 study of the Japan Adult Leukemia Study Group (JALSG).

All-trans-retinoic acid (ATRA) has been incorporated in front-line therapy for newly diagnosed acute promyelocytic leukemia (APL). We conducted a multicenter study of differentiation therapy with ATRA alone or in combination with chemotherapy followed by intensive postremission chemotherapy in patients with APL (the JALSG APL92 study), and analyzed prognostic factors to increase the cure rate in our subsequent trial. From 1992 to 1997, adult patients with newly diagnosed APL received oral ATRA 45 mg/m2 daily alone until complete remission (CR) if initial leukocyte counts were < 3.0x10(9)/l, and ATRA daily plus daunorubicin (DNR) 40 mg/m2x3 days plus enocitabine (BHAC) 200 mg/m2x5 days if leukocyte counts were > or =3.0 x 10(9)/l. If peripheral blasts exceeded 1.0x10(9)/l during therapy, DNRx3 days plus BHACx5 days was added. After CR was achieved, three courses of consolidation and six courses of maintenance/intensification chemotherapy were administered. Of 376 patients enrolled, 369 were evaluable (median age 46 years, range 15-86 years; median leukocyte counts 2.0x10(9)/l), and 333 (90%) achieved CR (94% of patients treated with ATRA alone, 88% with ATRA plus later chemotherapy, 89% with ATRA plus initial chemotherapy, and 86% with ATRA plus initial and later chemotherapy). At a median follow-up of 45 months, the predicted 6-year overall and event-free survival (EFS) rates for all patients were 65% and 52%, respectively. Favorable prognostic factors for CR were younger age, no or mild purpura, high serum total protein level, low lactate dehydrogenase level, and no or mild disseminated intravascular coagulation (DIC). Favorable prognostic factors for EFS were leukocyte counts < 10.0x10(9)/l, mild DIC, and no sepsis during induction therapy. In the JALSG APL97 study, we intensified chemotherapy for patients with leukocyte counts > or =3.0x10(9)/l, and are randomly testing whether further chemotherapy is required for APL patients with negative PCR for PML/retinoic acid receptor alpha in the maintenance phase.