Prognostic Value of Pretreatment Fetal Hemoglobin Levels in Patients with Myelodysplastic Syndromes and Acute Myeloid Leukemia Treated with Azacitidine: A Single-center Retrospective Study

Objective Azacitidine (AZA) has been the standard of care for elderly patients with high-risk myelodysplastic syndromes (MDS). However, reliable clinical predictors of outcome have yet to be identified. The prognostic value of fetal hemoglobin (HbF) levels has been reported for decitabine therapy. We evaluated pretreatment HbF levels in AZA monotherapy as a prognostic marker in MDS/acute myeloid leukemia (AML). Methods This study included chemotherapy-naïve patients who had received seven-day treatment schedules of AZA and whose HbF levels were measured at the onset of treatment between March 2011 and July 2020. Patients were grouped into HbF-normal (<1.0%) or HbF-elevated (≥1.0%) groups. Responses were classified according to the International Working Group 2006 criteria. Patients Twenty-nine patients were included and classified as having either MDS (n=21), chronic myelomonocytic leukemia (n=5), myelodysplastic/myeloproliferative neoplasm unclassifiable (n=1), or AML with <30% marrow blasts (n=2) based on the World Health Organization 2016 diagnostic criteria. According to the revised International Prognostic Scoring System classification, 20/29 patients were at intermediate, high, or very high risk. Pretreatment HbF levels were elevated in 13/29 patients. Results The median follow-up duration was 13.0 (range 1.5-93.5) months. The HbF-elevated group was associated with a significantly higher hematologic improvement rate (76.9% vs. 25%, p=0.009) and better overall survival (median, 21.0 vs. 13.0 months, p=0.048) than the HbF-normal group. Conclusion These results suggest that elevated pretreatment HbF levels can predict better outcomes in patients with MDS/AML treated with AZA.

Hairy Cell Leukemia-Japanese Variant: Report of a Patient and Literature Review

Hairy cell leukemia-Japanese variant (HCL-jv) shares some features with, but differs in other features from, HCL variant. Recently, it has been pointed out that HCL-jv and splenic diffuse red pulp small B-cell lymphoma (SDRPL) possibly constitute the same disease. We report a patient with HCL-jv, in which the neoplastic cells in the resected spleen were positive for CD11c, CD103, tartrate-resistant acid phosphatase (by immunohistochemistry), and weakly positive for cyclin D3. They were negative for CD25, CD123, annexin A1, and BRAF V600E-derived protein. Meta-analysis of HCL-jv cases in the literature showed considerable variation in the expression of HCL-related molecules. Although the clinical features and pattern of splenic involvement of HCL-jv are similar to those of SDRPL, some cytomorphological and phenotypical differences can be pointed out. To confirm whether the weak expression of cyclin D3 in our case suggests a spectrum from HCL-jv to SDRPL or one of the characteristics of HCL-jv, further studies on a large number of cases are necessary.

[Sequential development of mantle cell lymphoma following chronic lymphocytic leukemia]

Richter syndrome (RS) is the development of an aggressive lymphoma in patients with chronic lymphocytic leukemia (CLL). Most cases of diffuse large B-cell lymphoma variant of RS are clonally related to the original CLL. Here, we present a case of mantle cell lymphoma (MCL) that developed sequentially during the clinical course of CLL. A 72-year-old man had been diagnosed with CLL 16 years ago and was followed-up without treatment. He developed autoimmune hemolytic anemia 2 years ago, which resolved with rituximab and prednisolone treatment. Subsequently, he presented with fever, abdominal bloating, and fatigue. Progressive lymphocytosis and splenomegaly with elevated lactic dehydrogenase levels were suggestive of RS. Bone marrow examination revealed a small- to medium-sized lymphoid infiltrate, which was positive for CD5, CD20, CCND1, and SOX-11 and negative for CD23 and LEF1 on immunostaining. Fluorescence in situ hybridization analysis was positive for IgH/CCND1, which indicated MCL. Southern blot analysis showed that both the MCL and the previous CLL expressed different IgH gene rearrangement bands. At the time of relapse or progression of CLL, sequential development of MCL should be considered.

[Clinical significance of chronologic immature platelet fraction analysis in TAFRO syndrome]

TAFRO syndrome is characterized by thrombocytopenia with unknown etiology. The assessment of immature platelet fraction (IPF) is useful for differential diagnoses that include thrombocytopenia. However, the significance of IPF in cases of TAFRO syndrome remains to be reported. We present a case of TAFRO syndrome wherein the patient demonstrated a marked increase in IPF without thrombocytopenia, which offers vital information concerning TAFRO diagnosis and the serial measurements of IPF during treatment. A 65-year-old man presenting with fever was admitted to our hospital. He exhibited mild splenomegaly and lymphadenopathy, as well as rapidly worsening renal failure and fluid retention. These indications prompted the initiation of corticosteroid therapy. A normal platelet count and aberrantly high IPF implied abnormal thrombopoiesis, and subsequent bone-marrow findings suggested TAFRO syndrome. The platelet counts started to decrease following the corticosteroid therapy, but the treatment refractoriness prompted the urgent administration of rituximab. Thereafter, the platelet count nadir remained for approximately one month, whereas the decreasing IPF trend preceded platelet recovery. In the present case, a high pre-treatment IPF was demonstrated before the emergence of thrombocytopenia, and a decreasing trend of IPF was observed before platelet recovery during treatment. Therefore, serial IPF measurements could be useful for the early diagnosis and prognostication of TAFRO syndrome.

Meningeal infiltration of malignant lymphoma presenting with Froin's syndrome

Froin's syndrome is characterized by a combination of marked coagulation, elevated protein levels, and xanthochromia of the cerebrospinal fluid (CSF). It is due to blockage of CSF flow by a spinal cord mass or results from meningeal irritation during meningitis. However, Froin's syndrome has not been reported in hematological malignancies. Herein, we present two cases of lymphomatous leptomeningitis with Froin's syndrome. A 66-year-old man suffered consciousness disturbance during chemotherapy for a relapse of peripheral T-cell lymphoma, not otherwise specified. An 84-year-old man complained of pain and paralysis in both legs during chemotherapy for diffuse large B-cell lymphoma. In both cases, CSF analysis showed indications of Froin's syndrome, and cytology revealed lymphoma cells. In contrast to the highly elevated CSF protein levels, normal to only mildly elevated cell counts were not associated with advanced leptomeningeal disease. This is the first case report of leptomeningeal involvement in hematological malignancy associated with Froin's syndrome. As there are potentially undiagnosed cases including mild forms, Froin's syndrome should be kept in mind during CSF examination of patients with hematological malignancies.

[B-cell lymphoma developing de novo hepatitis B after salvage therapies including rituximab through seroconversion of surface antibody]

The patient was a 73-year-old woman. At 63 years of age, she had developed follicular lymphoma that showed a complete response to R-CHOP therapy. Over the subsequent 8 years, she experienced 4 relapses and was administered rituximab monotherapy once, combined rituximab-fludarabine therapy twice, and CHASE-R therapy once, achieving a complete response each time. Before her first therapy, hepatitis B virus (HBV) surface antigen was negative, while hepatitis B surface antibody (anti-HBs) and hepatitis B core antibody were not measured. Later, before her second salvage therapy, anti-HBs was negative, but then changed to positive before her third salvage therapy. HBV-DNA was negative before CHASE-R therapy. At 16 months after completing the CHASE-R therapy, she developed hepatitis and HBV-DNA had changed to positive. Hepatitis did not become fulminant and entecavir administration was effective. It was surmised that HBV had resolved, but she became negative for anti-HBs following the rituximab-containing chemotherapy. Therefore, this is a rare case in which de novo hepatitis developed after the final chemotherapy. The prognosis of patients with de novo hepatitis accompanying treatment of B-cell lymphoma is poor. In those who undergo lymphoma salvage therapy, the risk for and clinical course of HBV reactivation might differ from those of treatment-naïve patients.

NMR study of a novel RNA quadruplex structure

The structure of an RNA oligomer, r (GGAGGUUUUGGAGG) (R14-2) whose G-G steps are separated by adenine and uracil residues has been investigated by NMR. In the presence of 20 mM K+, a novel dimeric multiplex architecture is adopted by two strands of R14-2. In each strand a UUUU loop and two A residues connect four parallel G-G steps that pair-align into two tetrads. One of the tetrads is further pair-aligned by two A residues through the sheared mismatch and a novel hexad is subsequently formed. Two hexads coming from two different strands stack to make a dimeric multiplex. All of the guanosine and adenosine residues take an anti conformation.

New quadruplex structure of GGA triplet repeat DNA--an intramolecular quadruplex composed of a G:G:G:G tetrad and G(:A):G(:A):G(:A):G heptad, and its dimerization

The structure of d(GGAGGAGGAGGA) containing four tandem repeats of a GGA triplet sequence has been determined under physiological K+ conditions by NMR. d(GGAGGAGGAGGA) folds into an intramolecular quadruplex composed of a G:G:G:G tetrad and a G(:A):G(:A):G(:A):G heptad. Four G-G segments of d(GGAGGAGGAGGA) are aligned parallel to each other due to seven successive turns of the main chain at each of the GGA and GAGG segments. Two quadruplexes form a dimer stabilized through a stacking interaction between the heptads of the two quadruplexes. On the basis of these results, the biological implications of naturally occurring GGA triplet repeat DNA are discussed.

Sweet's syndrome evolved from recurrent erythema nodosum in a patient with myelodysplastic syndrome

A 63-year-old man had painful nodules on his lower legs. Microscopic examination showed septal and lobular panniculitis composed of lympho-histiocytic infiltrates. Based on the clinical and histopathological findings, the diagnosis of erythema nodosum (EN) was made. Nonsteroidal anti-inflammatory drugs were temporarily effective, but the eruptions had repeated to the present, and 16 months later, myelodysplastic syndrome (MDS) was diagnosed. Then, 6 months later, he developed a high fever and edematous fresh red-colored nodules on his neck, arm and upper trunk. Histopathologically, a diffuse, dense, dermal infiltrate of neutrophils was seen, and Sweet's syndrome (SS) was diagnosed. SS is known to develop in patients with MDS, and EN is one of the dermatoses that occur in conjunction with hematoproliferative disorders. Furthermore, SS evolving from recurrent EN and the simultaneous occurrence of SS and EN have been reported in some patients. In our case, we suggest that some mediators such as cytokines associated with MDS might have first induced EN, and then, as the MDS developed, they were replaced by others that caused SS.

An intramolecular quadruplex of (GGA)(4) triplet repeat DNA with a G:G:G:G tetrad and a G(:A):G(:A):G(:A):G heptad, and its dimeric interaction

The structure of d(GGAGGAGGAGGA) containing four tandem repeats of a GGA triplet sequence has been determined under physiological K(+) conditions. d(GGAGGAGGAGGA) folds into an intramolecular quadruplex composed of a G:G:G:G tetrad and a G(:A):G(:A):G(:A):G heptad. Four G-G segments of d(GGAGGAGGAGGA) are aligned parallel with each other due to six successive turns of the main chain at each of the GGA and GAGG segments. Two quadruplexes form a dimer stabilized through a stacking interaction between the heptads of the two quadruplexes. Comparison of the structure of d(GGAGGAGGAGGA) with the reported structure of d(GGAGGAN) (N=G or T) containing two tandem repeats of the GGA triplet revealed that although the two structures resemble each other to some extent, the extension of the repeats of the GGA triplet leads to distinct structural differences: intramolecular quadruplex for 12-mer versus intermolecular quadruplex for 7-mer; heptad versus hexad in the quadruplex; and three sheared G:A base-pairs versus two sheared G:A base-pairs plus one A:A base-pair per quadruplex. It was also suggested that d(GGAGGAGGAGGA) forms a similar quadruplex under low salt concentration conditions. This is in contrast to the case of d(GGAGGAN) (N=G or T), which forms a duplex under low salt concentration conditions. On the basis of these results, the structure of naturally occurring GGA triplet repeat DNA is discussed.

Functional expression of alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid receptors precedes the development of cholinergic phenotype in embryonic rat septal cells in culture

We examined the development of cholinergic neuronal functions and alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid (AMPA) responses in cultured embryonic rat septal cells. Choline acetyltransferase activity was increased from 4 to 6 days in culture and reached a plateau at day 8. Acetylcholine release was increased from 6 to 8 days in culture. AMPA-induced increase in intracellular Ca(2+) level was observed at 3 days in culture and most of the AMPA-responsive cells coincided with high-K(+) responsive cells. These results suggest that cholinergic neurons develop their neuronal functions about 8 days under cultured conditions, and functional expression of AMPA receptors precedes the cholinergic functional development.

Membrane enzyme systems responsible for the Ca(2+)-dependent phosphorylation of Ser(27), the independent phosphorylation of Tyr(10) and Tyr(7), and the dephosphorylation of these phosphorylated residues in the alpha-chain of H/K-ATPase

H/K-ATPase preparations (the G1 membrane) from pig stomach contain both kinases and phosphatases and show reversible phosphorylation of Tyr(7), Tyr(10), and Ser(27) residues of the alpha-chain of H/K-ATPase. The Tyr-kinase is sensitive to genistein and quercetin and recognized by anti-c-Src antibody. The Ser-kinase is dependent on Ca(2)(+) (K(0.5) = 0.9 microM), sensitive to a PKC inhibitor, and recognized by antibodies against PKCalpha and PKCbetaII. The addition of 3-[(3-cholamidopropyl)dimethylammonio]-1-propane-sulfonic acid (CHAPS) caused a dramatic increase in the phosphorylation of added synthetic copolymer substrates and permitted the phosphorylation of maltose-binding proteins fused with the N-terminal domain of alpha-chains. The phosphotyrosine phosphatase was inhibited by vanadate. The phosphoserine phosphatase was inhibited by okadaic acid and by inhibitor-2. The presence of protein phosphatase-1 was immunologically detected. Column chromatographic separation of CHAPS-solubilized G1 membrane and others indicate the apparent molecular weight of the Src-kinase to be approximately 60 kDa, the PKCalpha and/or PKCbII to be approximately 80 kDa, the Tyr-phosphatase to be 200 kDa, and PP-1 to be approximately 35 kDa. These data show that these membrane-bound enzyme systems are in sufficiently close proximity to be responsible for reversible phosphorylation of Tyr(7), Tyr(10), and Ser(27) of the catalytic subunit of membrane H/K-ATPase in parietal cells, the physiological role of which is unknown.

Direct evidence for in vivo reversible tyrosine phosphorylation of the N-terminal domain of the H/K-ATPase alpha-subunit in mammalian stomach cells

In vivo reversible phosphorylation of Tyr-7 and Tyr-10 of the pig stomach H/K-ATPase alpha-chain was initially demonstrated in mammals, rat, rabbit, and pig, in the presence of vanadate + H(2)O(2). In vitro phosphorylation has also been unequivocally demonstrated via the use of protease inhibitors during membrane H/K-ATPase preparation. An amphoretic detergent permitted each intrinsic kinase to phosphorylate each fusion protein containing the requisite Tyr residues, along with a reduction in alpha-chain phosphorylation. These and other data suggest that some important enzyme systems are present in the apical membrane and that they are in sufficient proximity to participate in the reversible phosphorylation of the amino terminal soluble domain of the alpha-chain with an unknown physiological function in the membrane embedded H/K-ATPase.

[Development of 18F-FDG ([F-18]-2-fluoro-2-deoxy-D-glucose) injection for imaging of tumor reflecting glucose metabolism--results of preclinical studies]

Fluorine-18-2-fluoro-2-deoxy-D-glucose (18F-FDG) injection was prepared by a modification of a method originally developed by Hamacher et al. The dosage form is the injectable solution (2 ml) containing 185 MBq of 18F-FDG at a calibration time. Preclinical studies of the agent were performed. Its radiochemical purity is more than 95% and expiration time is 4 hours after the calibration time at ambient temperature. No toxicity was observed with up to 200 mg/kg and 100 mg/kg of non-radioactive FDG intravenously injected to rats and dogs in single-dose toxicity tests, respectively. Biodistribution studies demonstrated that the radioactivity was mainly distributed into brain (3.0 to 3.3% I.D./Organ at 30 minutes) and heart (4.2 to 5.8% I.D./Organ at 1 to 3 hours) after intravenous injection of the agent to normal rats. In a tumor transplanted mouse model (colon 26), tumor uptake was 10.9 +/- 3.5% I.D./g at 1 hr after intravenous injection of the agent, the radioactivity was retained until 3 hours. The radiation absorbed dose was estimated according to the MIRD Pamphlet based on the biodistribution data both in humans reported by Mejia et al. and rats described in this report. The radiation absorbed dose was not higher than those of commercially available radiopharmaceuticals. In conclusion, the 18F-FDG injection is expected to be useful for further clinical application.

The structures of nucleic acids composed exclusively of non-standard base pairs

We have reported that d(GGAGGAA) forms a new type of quadruplex in the presence of K+. Here we report that in the absence of K+ it forms another kind of new structure composed of non-standard base pairs exclusively. The structure is neither a quadruplex nor a hairpin. The structure gives three clear imino proton signals of G at 10.0, 13.0 and 13.8 ppm, indicating the formation of G:A and/or G:G base pairs. The two signals at 13.0 and 13.8 ppm indicate that there are two base pairs in which the imino protons of G are hydrogen bonded. All residues take anti conformation, which imposes the restriction on the combination of a mutual direction of strands and types of base pairs. Phosphorus signals of the second and fifth residues appear at higher field, while that of the seventh residue at lower field, when compared with those of A and B form structures, suggesting deviations of a backbone conformation from the standard one. Replacement of the second or fifth G by I results in destabilization of the structure, which implies the involvement of amino groups of these residues in base pairing. On the basis of these results, the structure of d(GGAGGAA) is discussed.

Structural characterization of a DNA duplex modeled on a DNA:RNA hybrid of the polypurine tract recognized by a reverse transcriptase

The structure of d(TTAAAAGAAAAGGG):d(CCCTTTTCTTTTAA) has been characterized by NMR. The minor grooves of the two dA-tracts are suggested to be rather narrow, and the portion linking the two dA tracts exhibits a slightly deviated structure from a standard B DNA, in order to maintain the narrowness of the minor groove. The structure of the dG-tract is also slightly deviated. Additionally, specific broadening of resonances is observed for the residues at or near the junction between the dA-tract and the dG-tract, suggesting local structural polymorphology.

Nerve growth factor treatment induces high-potassium-evoked calcium-dependent acetylcholine release in cultured embryonic rat septal cells

The effects of dibutyryl cAMP (dbcAMP) and nerve growth factor (NGF) on acetylcholine (ACh) release from primary cultured cells of embryonic rat septum were studied. Both dbcAMP and NGF increased the activity of choline acetyltransferase and contents of intracellular and spontaneously released ACh without affecting the total protein content. High-potassium-evoked ACh release was observed in NGF-treated cells but not in untreated and dbcAMP-treated cells. These results indicate that NGF induces cholinergic maturation from induction of the ACh-synthetic enzyme to the excitation-secretion processes.

Formation of sheared G:A base pairs in an RNA duplex modelled after ribozymes, as revealed by NMR

The thermal stability and structure of an RNA duplex, r(GGACGAGUCC)2, the base sequence of which was modelled after both a hammerhead ribozyme and a lead ribozyme, were studied by CD and NMR. We previously demonstrated that the corresponding DNA duplex, d(GGACGAGTCC)2, formed unique 'sheared' G:A base pairs, where an amino proton, instead of an imino proton, of G is involved in the hydrogen bonding, and G and A bases are arranged 'side by side' instead of 'head to head' (Nucleic Acids Res. (1993) 21, 5418-5424). CD melting profiles showed that the RNA duplex is thermally more stable than the corresponding DNA duplex. NMR studies revealed that sheared G:A base pairs are formed in the RNA duplex, too, although the overall structure of the RNA is the A form, which differs from the B form taken on by the corresponding DNA. A model building study confirmed that sheared G:A base pairs can be accommodated in the double helical structure of the A form. A difference between the RNA and DNA duplexes in the stacking interaction involving G:A mismatch bases is also suggested. The demonstration that sheared G:A base pairs can be formed not only in DNA but also in RNA suggests that this base pairing plays an important role regarding the RNA structure.

Structural studies of DNA and RNA containing AG base pairs by NMR

Base pairing between A and G residues has been suggested in some ribozymes and the structure derived from this non-standard base pairing could play a crucial role in enzymatic actions of the ribozymes. We have studied the structures of three DNAs and an RNA that base sequences were modeled after the ribozymes by NMR. It was found that the A and G residues can form a basepair in a very unique fashion both in the DNAs and RNA. "Side" instead of "head to head" alignment of the two bases was found, where an amino proton instead of an imino proton of the G residue is involved in the hydrogen bonding. As a result of the unique basepairing, certain bases stack over the bases of the opposite strand instead of over the ones of the same strand. It was also shown that the formation and thermal stability of this unique AG basepair depend on the neighbouring base sequences. Moreover existence of the unique AG basepairs was suggested in a real small metalloribozyme itself.

[Electron microscopic cytochemistry of pseudo-Chediak-Higashi granules in 5 cases of AML]

Blasts from 5 cases of AML with pseudo-Chediak-Higashi granules were examined ultrastructurally and histocytochemically using peroxidase, acid phosphatase, high iron diamine (HID) and periodic acid-thiocarbohydrazide-silver proteinate (PA-TCH-SP) stainings. Pseudo-Chediak-Higashi granules, which appeared as vacuole-like inclusions by light microscopy, generally contained electron-lucent materials. All pseudo-Chediak-Higashi granules were, positive for peroxidase but some were negative for acid phosphatase. Pseudo-Chediak-Higashi granules were HID positive, indicating that they contained sulfated glycoconjugates. Glycogen-like particles were observed in the pseudo-Chediak-Higashi granules with the PA-TCH-SP method, as occasionally observed in granules in drug resistant ALL blasts. In conclusion, the contents of pseudo-Chediak-Higashi granules, which seems to be formed by fusion of small granules, differed from those of normal azurophillic granules.

Fluorescence irido-corneal photography

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