Induction of differentiation and apoptosis in human promyelocytic leukemia HL60 cell line by a new type of steroids

Mer-NF8054X is a new type of steroid whose structure has been established as 11-oxo-18, 22-cycloergosta-6, 8(14)-diene-3beta, 5beta, 9beta, 23S-tetraol (an 18, 22-cycloergostane), which has been reported to have antifungal activity against Aspergillus fumigatus. However, other biological activities are unknown. Herein, we reported that Mer-NF8054X inhibited cell growth of HL60 human leukemia cells, when used either singly or in combination with retinoic acid (RA). In addition, Mer-NF8054X alone induced differentiation and apoptosis of HL60 cells. The induction of differentiation of HL60 cells by Mer-NF8054X was synergistic in combination with RA. On the other hand, Emesterone A, an analogue of Mer-NF8054X which is missing a hydroxy residue from the third position, showed much lower activity than Mer-NF8054X on the inhibition of cell growth and the induction of cell differentiation and apoptosis. However, Emesterone B, an analogue of Emesterone A which is missing a hydroxy residue from the fifth position, showed higher activity than Emesterone A but lower activity than Mer-NF8054X when examined for the inhibition of cell growth and the induction of cell differentiation and apoptosis. These results suggested that Mer-NF8054X and its analogs may be a new type of differentiation inducing agent. The hydroxy residue at the third position or fifth position in Mer-NF8054X may be necessary, but not essential, for inhibition of growth and induction of both differentiation and apoptosis of HL60 cells. In addition, Mer-NF8054X enhanced the differentiation of HL60 cells induced by RA. Based on these results, Mer-NF8054X may have utility in the clinic in combination with RA for leukemia patients.

Differential expression and internal feedback regulation of 1-aminocyclopropane-1-carboxylate synthase, 1-aminocyclopropane-1-carboxylate oxidase, and ethylene receptor genes in tomato fruit during development and ripening

We investigated the feedback regulation of ethylene biosynthesis in tomato (Lycopersicon esculentum) fruit with respect to the transition from system 1 to system 2 ethylene production. The abundance of LE-ACS2, LE-ACS4, and NR mRNAs increased in the ripening fruit concomitant with a burst in ethylene production. These increases in mRNAs with ripening were prevented to a large extent by treatment with 1-methylcyclopropene (MCP), an ethylene action inhibitor. Transcripts for the LE-ACS6 gene, which accumulated in preclimacteric fruit but not in untreated ripening fruit, did accumulate in ripening fruit treated with MCP. Treatment of young fruit with propylene prevented the accumulation of transcripts for this gene. LE-ACS1A, LE-ACS3, and TAE1 genes were expressed constitutively in the fruit throughout development and ripening irrespective of whether the fruit was treated with MCP or propylene. The transcripts for LE-ACO1 and LE-ACO4 genes already existed in preclimacteric fruit and increased greatly when ripening commenced. These increases in LE-ACO mRNA with ripening were also prevented by treatment with MCP. The results suggest that in tomato fruit the preclimacteric system 1 ethylene is possibly mediated via constitutively expressed LE-ACS1A and LE-ACS3 and negatively feedback-regulated LE-ACS6 genes with preexisting LE-ACO1 and LE-ACO4 mRNAs. At the onset of the climacteric stage, it shifts to system 2 ethylene, with a large accumulation of LE-ACS2, LE-ACS4, LE-ACO1, and LE-ACO4 mRNAs as a result of a positive feedback regulation. This transition from system 1 to system 2 ethylene production might be related to the accumulated level of NR mRNA.

Development of a dissecting aneurysm on the vertebral artery immediately after occlusion of the contralateral vertebral artery: a case report

A 49 year old female presented with subarachnoid hemorrhage due to a ruptured dissecting aneurysm on the left vertebral artery (VA). Following an occlusion test, we performed proximal occlusion of the left VA with detachable balloons. However, a dissecting aneurysm on the right VA developed three weeks later. After an occlusion test had showed no change in cerebral blood flow, auditory brain stem response, or neurological status, proximal occlusion of the right VA was performed. The patient has returned to normal life without neurological deficits. Bilateral dissecting aneurysms of the VA are quite common, but de novo VA dissecting aneurysms or enlargement of such aneurysms after occlusion of contralateral VA are rare. This case suggests that hemodynamics stress may be a causal factor in the development of VA dissecting aneurysms. Careful pre- and post-operative neuroradiological examination of the contralateral VA are required in patients undergoing VA occlusion for dissecting aneurysms.

Probing pore topology and conformational changes of Kir2.1 potassium channels by cysteine scanning mutagenesis

Using cysteine (Cys) scanning mutagenesis of the inward rectifier K+ channel Kir2.1, we investigated its pore structure and putative conformational changes. In the background of the Kir2.1 mutant C149F which showed no sensitivity towards Cys-modifying reagents, Cys residues were introduced at 10 positions in the H5 pore region. Out of six functional mutants, T141C and F147C showed clear changes in current amplitude when Cys-modifying reagents were applied from the external side. These results suggest that the corresponding sections of the H5 pore region face to the external side which is in contrast to the results previously obtained for voltage-gated K+ (Kv) channels. Using the mutants T141C and F147C, we investigated whether or not Kir2.1 channels show state-dependent conformational changes of the pore structure. Substantial alterations of the holding potential or external K+ concentration, however, did not cause any significant change in the speed of channel modification upon application of Cys-specific reagents, suggesting that Kir2.1 channels do not undergo conformational changes, in contrast to C-type inactivating Kv channels.

[Hemophagocytic syndrome associated with tuberculosis and mycoplasma infection in two patients]

Patient 1: A 48-year-old man was admitted to Osaka Red Cross Hospital because of fever and dyspnea. Laboratory examination revealed pancytopenia, liver dysfunction and hematostatic abnormality. Chest radiographs obtained on admission revealed ground-glass opacity in both lung fields, and an analysis of arterial blood showed severe hypoxemia (PaO2:46.8 Torr). Pulse therapy with methylprednisolone was started. Although the hypoxemia subsided and radiographic findings rapidly improved, pancytopenia persisted. Examination of bone marrow aspirate revealed mature histiocytes with marked hemophagocytosis. Amplified Mycobacterium tuberculosis direct tests of bronchoalveolar lavage fluid, sputum, urine, and bone marrow were all positive, and Mycobacterium tuberculosis was cultured from sputum and urine. Although the patient was taking antituberculous agents, his pancytopenia persosted. Treatment with etoposide induced remssion. Patient 2: A 19-year-old woman was admitted to Osaka Red Cross Hospital because of prolonged cough and fever. Laboratory examination revealed leukocytosis, liver dysfunction, and hematostatic abnormality. Serologic tests provided conclusive evidence of Mycoplasma infection and a CRP test was strongly positive. Chest radiographs obtained on admission revealed infiltration shadows in the middle and lower lung fields on both sides, with left pleural effusion. An analysis of arterial blood showed hypoxemia (PaO2: 54.2 Torr). Examination of bone marrow and pleural effusion samples revealed mature histiocytes with marked hemophagocytosis. Although treatment with antibiotics and pulse therapy with methylprednisolone was started, the patients respiratory functions deteriorated. Endotracheal intubation was performed. Therapy with etoposide induced remission. Hemophagocytic syndrome associated with Mycoplasma infection and tuberculosis appears to be exceedingly rare. In these 2 cases, it was difficult to achieve remission with therapy for the underlying infections, but etoposide treatment was effective.

Treatment of primary varicose veins: an assessment of the combination of high saphenous ligation and sclerotherapy

This study was conducted to determine the optimal treatment for minimizing the recurrence of varicose veins, and to assess the value of the combined treatment of high saphenous ligation and sclerotherapy. A combined total of 967 limbs in 660 patients with primary varicose veins were treated. The treatments comprised: sclerotherapy alone in 81 limbs, high saphenous ligation alone in 3 limbs, a combination of sclerotherapy and high saphenous ligation in 843 limbs, and a combination of sclerotherapy and ligation of incompetent perforating veins in 10 limbs. Recurrent varicose veins appeared from 3 months after the initial treatment in 61 (6.3%) limbs. Saphenous-type recurrence, being the presence of saphenofemoral incompetence (SFI) and/or saphenopopliteal incompetence (SPI), was found in 20 limbs, and further treatment was given. Segmental-type recurrence, being superficial varices without SFI or SPI, was found in 41 limbs, all of which were treated with further sclerotherapy alone. To minimize the recurrence rate of varicose veins, the presence or absence of SFI, SPI, and incompetent perforating veins must be confirmed prior to the initial treatment. It was concluded that the combination of high saphenous ligation and sclerotherapy is effective for patients with SFI and/or SPI, whereas sclerotherapy alone is better for patients without SFI or SPI.

Isolation of a cDNA for a novel 120-kDa GTP-binding protein expressed in motor neurons in the salmon brain

We isolated a cDNA encoding a novel protein with GTP-binding motifs from the salmon brain. The cloned 5.5-kb cDNA encoded 971 amino acids, which showed limited homology with members of large GTP-binding proteins, such as dynamin, MX protein and VPS1. By in vitro translation analysis, the size of the encoded protein was estimated to be 120 kDa. The recombinant protein including the putative GTP-binding domain was shown to bind to GTP in vitro. mRNA was strongly expressed in the brain, ovary and skeletal muscle. In the brain, expression of the mRNA was observed specifically in motor neurons, in nucleus oculomotorius, in nucleus valvulae lateralis, in the medulla oblongata and in the spinal cord. To determine the cell biological significance of the encoded protein, we transfected CHO cells with wild type or a putative constitutive active mutant of the mG120 (120-kDa G protein expressed in motor neurons) and examined morphological changes. However, no clear changes were observed. The functional role of this novel motor neuron-specific large GTP-binding protein remains to be elucidated.

Comparison of the open-close kinetics of the cloned inward rectifier K+ channel IRK1 and its point mutant (Q140E) in the pore region

To test whether a single amino-acid residue at the center of pore region can dictate the difference of open-close kinetics in a steady-state at hyperpolarized potentials among members of the inward K+ channel family, the Q140E mutant of the inward rectifier K+ channel (IRK1) was made and its gating properties were compared with those of IRK1 wild type (Wt) in Xenopus oocytes. The distinct differences were observed only at the single channel level. The open time constant of mutant tau(o)(Q140E) at -80 mV was over ten-fold shorter than that of Wt tau(o)(Wt); in Wt, the closed time distribution was fitted with a sum of two exponentials (c-slow and c-fast), whereas it could be fitted with three exponentials (c-slow, c-fast, and additional c-extrafast) in Q140E. However, the time constant of burst duration of mutant tau(b)(Q140E) was close to tau(o)(Wt) and both showed a similarly strong voltage dependence, and a high sensitivity to pH0 in the absence of Mg02+, indicating that tau(b)(Q140E) is closely related to tau(o)(Wt). These results demonstrated that Q140E shortened the channel openings by acquiring an extra-fast closing state. From the analysis of the effects of cations on both Wt and Q140E, it was suggested that the transition from the open state to this extra-fast closing state was not due to the block by H+ or Mg2+ but possibly by extracellular K+.

KQT2, a new putative potassium channel family produced by alternative splicing. Isolation, genomic structure, and alternative splicing of the putative potassium channels

Potassium (K+) channels are critical for a variety of cell functions, including modulation of action potentials, determination of the testing membrane potential, and development of memory and learning. Eleven mouse cDNA clones homologous to the new human putative K+ channel (designated HNSPC, which we recently reported) were isolated from the brain cDNA libraries. All these proteins coded by the isolated cDNAs were identical from the N-terminal to the sixth transmembrane domain, but exhibited differences in the sequence and length of the C-terminal cytoplasmic region. Analyses of the mouse genomic DNAs showed that these clones originated from a single gene located on mouse chromosome 2H3-4, which proved that these clones were generated by alternative RNA splicing. Since all isoforms showed significant structural identity with KVLQT1 (64% identity in the transmembrane domains), which is known to associate with IsK, they were designated mKQT2.1-mKQT2.11. Northern blot analysis indicated that the mRNAs of the mKQT2 isoforms were exclusively expressed in the brain. In the mouse cerebellum region, the localized expression of these clones in the Purkinje cell layer and Golgi cells was shown by in situ hybridization analysis. These transcripts were also detected in the mouse embryonic developmental stage (11th, 15th and 17th day); and in particular, the mRNAs for shorter forms (mKQT2.9, mKQT2.10 or mKQT2.11) were abundantly found on the 11th day after gestation. Although these mKQT2 isoforms had the characteristic structure of voltage-gated K+ channels, functional expression of K+ currents were not detected in Xenopus oocytes.

Peripheral ulcerative keratitis associated with erythema elevatum diutinum and a positive rheumatoid factor: a report of three cases

Peripheral ulcerative keratitis (PUK) is a complication of collagen-vascular diseases such as rheumatoid arthritis (RA) and other systemic vasculitides. We report three cases of erythema elevatum diutinum with PUK. These patients presented with nodules and plaques consistent with erythema elevatum diutinum on the extremities and crusted or ulcerated purpuric lesions on the soles. Histopathological examination of these lesions revealed a dense neutrophilic infiltrate with nuclear dust and fibrin around blood vessels. All the patients developed PUK concomitant with the development of the skin lesions. The rheumatoid factor was positive at high titre in all three patients; this was associated with probable RA in one. Cutaneous lesions were dramatically improved by administration of dapsone in all cases. Dapsone was also effective in treating the ocular lesions in two patients.

Role of medial smooth muscle cell function in antithrombogenicity of vein grafts

OBJECTIVES

To determine the significance of prostaglandin I2 (PGI2) production by medial smooth muscle cells (SMCs), we assessed PGI2 production from denuded vein grafts and their antithrombogenicity.

MATERIALS AND METHODS

A total of 30 dogs were divided into two groups: in group I, 14 dogs (27 veins, 188 segments) were used to assay PGI2 production, which was measured as 6-keto-PGF1 alpha. In group II, 16 dogs were used for an implantation study and the thrombus-free surface (TFS) score was calculated 24 h after implantation. Both groups contained the following subgroups: subgroup A, freshly harvested veins; subgroup B, endothelial denuded veins; subgroup C, veins frozen and cryopreserved; subgroup D, veins treated with protease.

RESULTS

Values of 6-keto-PGF1 alpha (pg/mg/min) for basal and stimulated states in subgroup I-A through I-D were 58.0 +/- 8.9 and 530.6 +/- 74.7, 26.3 +/- 4.7 and 82.3 +/- 11.4, 17.9 +/- 1.3 and 39.4 +/- 3.3, and 13.3 +/- 1.8 and 32.2 +/- 6.2, respectively. The PGI2 production in subgroup I-A were significantly higher than those in the other three subgroups (p < 0.01 for basal and stimulated), while the production in subgroup I-B was also significantly higher than those in the remaining two (p < 0.05 for basal and stimulated). The TFS scores in subgroup II-A through II-D were 98 +/- 2%, 90 +/- 2%, 38 +/- 5%, and 15 +/- 7%, respectively, showing significantly superior antithrombogenicity in subgroup II-B, as well as in II-A, when compared with the remaining two (p = 0.014).

CONCLUSION

The amount of PGI2 generated by the medial SMCs may be sufficient for maintaining the antithrombogenicity of the endothelial denuded AVGs.

Structural basis for a Ca2+-sensing function of the metabotropic glutamate receptors

The metabotropic glutamate receptors (mGluRs) are widely distributed in the brain and play important roles in synaptic plasticity. Here it is shown that some types of mGluRs are activated not only by glutamate but also by extracellular Ca2+ (Ca2+o). A single amino acid residue was found to determine the sensitivity of mGluRs to Ca2+o. One of the receptors, mGluR1alpha, but not its point mutant with reduced sensitivity to Ca2+o, caused morphological changes when transfected into mammalian cells. Thus, the sensing of Ca2+o by mGluRs may be important in cells under physiological condition.

Cyclosporin A selectively reduces the functional expression of Kir2.1 potassium channels in Xenopus oocytes

The immunosuppressant cyclosporin A (CsA) reduced the functional expression of Kir2.1 potassium channels in Xenopus oocytes in a dose-dependent manner with an IC50 of 11 microM when the oocytes were incubated with CsA after RNA injection. FK506 was less effective than CsA; cyclosporin H, a non-immunosuppressive derivative of CsA, did not have a significant effect. CsA did not impair protein synthesis since other potassium channel types (Kir1.1, Kv1.1, Kv1.4) were much less sensitive to CsA. Our results suggest that the functional expression of Kir2.1 channels is facilitated by the peptidyl-prolyl isomerase cyclophilin. The observations illustrate a new role of CsA in regulation of membrane ion transport, and may provide an alternative explanation for CsA-induced side effects in clinical use.

Mutation of the fibroblast growth factor receptor 2 gene in Japanese patients with Apert syndrome

Apert syndrome is a clinically distinctive condition characterized by craniosynostosis, mid-face hypoplasia, and severe symmetrical syndactyly of the hands and feet. Recently, mutations of the fibroblast growth factor receptor 2 (FGFR2) gene have been associated with several craniosynostosis conditions including Apert, Crouzon, Jackson-Weiss, and Pfeiffer syndromes. Mutations detected in Crouzon, Jackson-Weiss, and Pfeiffer syndromes are located at several sites in the FGFR2 gene. However, the mutational spectrum in Apert syndrome is remarkably narrow. Mutations detected thus far in Caucasian patients with this syndrome are exclusively transversions from cytosine to guanine at either nucleotide position 934 (C934G) or 937 (C937G) in the FGFR2 gene. To examine the possibility that the narrow mutational spectrum in Apert syndrome was a result of racial or environmental predilection, we studied three Apert syndrome patients from two unrelated Japanese families for C934G and C937G mutations. The C934G mutation was found in all three patients. This is the first demonstration of FGFR2 gene mutations in Japanese patients. Our evidence that the C934G mutation identified in Caucasian patients also occurs among Japanese patients excludes the possibility of racial or environmental predilection for this mutation. Nucleotide position 934 is a mutational hotspot of the FGFR2 gene in Japanese patients as well, although the mechanism by which the mutation occurs remains to be clarified. Whether C937G is a mutational hotspot in Japanese patients as well remains to be determined.

Thoracic spinal angiomyolipoma with extracanal extension to the thoracic cavity. A case report

STUDY DESIGN

Case report and review of the literature.

OBJECTIVE

To describe a 72-year-old man with thoracic spinal angiomyolipoma in the ventral aspect of the epidural space and extracanal extension to the posterior mediastinum, to discuss the clinical and radiologic features and unique biologic behavior of this entity, and to review of the literature on angiolipoma and angiomyolipoma.

SUMMARY OF BACKGROUND DATA

Spinal angiolipoma and angiomyolipoma are rare tumors, which are localized almost exclusively in the dorsal epidural space of the thoracic spine. Most reported cases have no tendency to involve the surrounding tissue.

METHODS

The authors describe the radiologic, surgical, and pathologic findings of this patient and review the findings from other reported cases.

RESULTS

Anterior decompression was performed using a right transthoracic incision, and the neurologic symptoms improved immediately. There were no signs of recurrence of the tumor or neurologic deficit within a 2-year follow-up period.

CONCLUSION

Results of a literature survey of these tumors support management by prompt and radical surgical intervention for long-term cure, even in cases in which the infiltrating nature is recognized.

Isolated right ventricular hypoplasia: intraoperative balloon occlusion test

A 42-year-old woman with isolated right ventricular hypoplasia underwent operation. To determine the optimal procedure, we temporarily occluded the atrial septal defect with a balloon catheter that was introduced through the right atrial appendage. The hemodynamics were stable throughout the occlusion test. Simple closure of the atrial septal defect was safely accomplished. Intraoperative occlusion test with the balloon catheter was a good alternative to preoperative occlusion test.

[Intraoperative coronary artery spasm treated by percutaneous cardiopulmonary support in a patient with left lung cancer]

A 53-year-old man with left lung cancer underwent left upper lobectomy and extended mediastinal lymphadenectomy. Shortly before the end of the operation, electrocardiogram showed elevation of ST wave and multiple ventricular premature contractures first, then ventricular fibrillations, and finally cardiac arrest. Coronary artery spasm was strongly suspected. The patient was resuscitated by cardiac massage and countershock immediately, however, such attacks repeated several times. As medication and cardiac pacing were not effective, percutaneous cardiopulmonary support (PCPS) was established. The hemodynamics was stabilized with PCPS. He was weaned off PCPS the next day. He was discharged and has had no attack so far. PCPS is an excellent modality for intraoperative coronary spasm which is uncontrollable by medicines and other methods.

Right-sided pedunculated hepatocellular carcinoma: a form of adrenal metastasis

Pedunculated hepatocellular carcinoma (HCC) or extrahepatic growth of HC C is an uncommon but not rare pathological form, but its genesis is unknown. Right-sided adrenal metastases of HCC that were abutting on or about to fuse with the right hepatic lobe were resected in three patients. The masses seemed to have originated in the para-adrenal tissue, leaving the adrenal gland intact. They were partially supplied by the hepatic artery as well as by the suprarenal artery. Four cases of autopsied pedunculated HCC of the right lobe were also studied. The mass was protruding caudad from the noncancerous parenchyma of the right lobe. Postmortem angiography carried out on one liver showed that only a small portion of the mass toward the liver was supplied from the hepatic artery. These observations suggest that some, perhaps most, of the right-sided pedunculated HCCs represent fusion of the right lobe and para-adrenal or adrenal metastatic HCC. This phenomenon may be explained by possible transport of cancer cells toward the right adrenal gland through the so-called adrenohepatic fusion, a relatively common anatomical change in advanced age.

Satigrel, a new antiplatelet agent, inhibits platelet accumulation in prosthetic arterial grafts

BACKGROUND

Early and late vascular obstruction are both related to platelet adhesion and aggregation in the grafts. We assessed the effect of satigrel, a new oral antiplatelet agent, on the accumulation of indium-labeled platelets in knitted Dacron grafts inserted proximal to the femoral artery.

METHODS

Nine patients with arteriosclerosis obliterans receiving grafts were treated with satigrel, and 10 others were enrolled as untreated controls. Scintigraphy was performed in postoperative weeks 2 and 4, and the ratio of the scintillation count of the graft to that of the native artery was calculated to assess platelet accumulation.

RESULTS

In both weeks 2 and 4, the ratio was significantly smaller in the satigrel group than in the control group for the whole graft, the proximal anastomosis, and the distal anastomosis.

CONCLUSIONS

Satigrel significantly inhibited platelet accumulation in vascular grafts and thus may be useful for preventing postoperative graft occlusion.

RGS8 accelerates G-protein-mediated modulation of K+ currents

Transmembrane signal transduction via heterotrimeric G proteins is reported to be inhibited by RGS (regulators of G-protein signalling) proteins. These RGS proteins work by increasing the GTPase activity of G protein alpha-subunits (G alpha), thereby driving G proteins into their inactive GDP-bound form. However, it is not known how RGS proteins regulate the kinetics of physiological responses that depend on G proteins. Here we report the isolation of a full-length complementary DNA encoding a neural-tissue-specific RGS protein, RGS8, and the determination of its function. We show that RGS8 binds preferentially to the alpha-subunits G(alpha)o and G(alpha)i3 and that it functions as a GTPase-activating protein (GAP). When co-expressed in Xenopus oocytes with a G-protein-coupled receptor and a G-protein-coupled inwardly rectifying K+ channel (GIRK1/2), RGS8 accelerated not only the turning off but also the turning on of the GIRK1/2 current upon receptor stimulation, without affecting the dose-response relationship. We conclude that RGS8 accelerates the modulation of G-protein-coupled channels and is not just a simple negative regulator. This property of RGS8 may be crucial for the rapid regulation of neuronal excitability upon stimulation of G-protein-coupled receptors.