Neoplastic transformation of normal hematopoietic cells by constitutively activating mutations of c-kit receptor tyrosine kinase

The c-kit proto-oncogene encodes a receptor tyrosine kinase that is crucial to hematopoiesis, melanogenesis, and gametogeneis. Although the enzymatic activity of the c-kit product (KIT) is regulated by its ligand, both the Val559-->Gly (G559) mutation in the juxtamembrane domain and the Asp814-->Val (V814) mutation in the phosphotransferase domain lead to constitutive activation of KIT. By retroviral infection of hematopoietic progenitor cells with KIT(G559) or KIT(V814), KIT(G559) induced development of granulocyte/macrophage and mast-cell colonies in vitro without the addition of exogenous growth factors. KIT(V814) induced factor-independent growth of various types of hematopoietic progenitor cells, resulting in the development of mixed erythroid/myeloid colonies in addition to granulocyte/macrophage and mast-cell colonies. Furthermore, transplantation of KIT(G559) and KIT(V814)-infected bone marrow cells led to development of acute leukemia in one of 10 and six of 10 transplanted mice, respectively. No mice developed hematologic malignancies after transplantation of wild-type KIT-infected cells. Furthermore, transgenic mice expressing KIT(V814) developed acute leukemia or malignant lymphoma. These results demonstrate a direct role of the mutant KITs, particularly KIT(V814), in tumorigenesis of hematopoietic cells and suggest that similar mutations may contribute to the development of human hematologic malignancies.

Repeated allergen exposure enhances excitatory nonadrenergic noncholinergic nerve-mediated bronchoconstriction in sensitized guinea-pigs

The effect of repeated allergen inhalation challenge on the airway excitatory nonadrenergic noncholinergic (e-NANC) nerve-mediated bronchoconstrictor response was studied in ovalbumin (OA) sensitized guinea-pigs. Three weeks after sensitization, OA inhalation, 0.03% for 3 min (challenged group), or saline inhalation (control group) was repeated every day for 4 weeks. The e-NANC nerve function was examined in vitro by means of isometric tension measurement of main bronchi. After pretreatment with atropine (10(-6) M) and propranolol (10(-6) M), we performed electrical field stimulation (EFS) or exogenous neurokinin A (NKA) administration. In the challenged group, EFS-induced main bronchial contraction was significantly greater than that of the control group (p < 0.05 or p < 0.01), but exogenous NKA-mediated responses were almost the same in both groups. The e-NANC-induced main bronchial contractions after EFS were enhanced by pretreatment with the neutral endopeptidase inhibitor, phosphoramidon, to the same degree in the control and challenged groups, indicating that the peptide degradation mechanisms were not impaired even in the challenged group. Substance P immunoreactivities in the lung of the challenged group were significantly higher than those of the control group. These results suggest that chronic airway inflammation after repeated allergen challenge increases excitatory nonadrenergic noncholinergic nerve function, possibly by enhancing sensory neuropeptide production and/or release.

Endogenous nitric oxide modifies antigen-induced microvascular leakage in sensitized guinea pig airways

To examine the role of endogenous nitric oxide in allergic airway inflammation, we investigated the effect of a nitric oxide synthase inhibitor, N omega-nitro-L-arginine methyl ester (l-NAME), on antigen-induced airway microvascular leakage in actively sensitized guinea pigs by using Evans blue dye. Three weeks after sensitization with ovalbumin (10 micrograms), the tracheas were cannulated, and lungs were artificially ventilated. Animals were pretreated with atropine and propranolol (both 1 mg/kg, intravenously) to avoid neural modification. Ovalbumin inhalation (3 mg/ml, 1 minute) challenge caused significant microvascular leakage in all airways portions, which was significantly suppressed in a dose-dependent manner by pretreatment with intravenous injection of L-NAME (1 and 10 mg/kg) but not with the inactive enantiomer D-NAME (10 mg/kg). This inhibition by L-NAME was significantly reversed by co-administration of L-arginine (100 mg/kg, intravenously). Pretreatment with a vasoconstrictor, phenylephrine (20 micrograms/kg, intravenously), had no inhibitory effects on antigen-induced airway microvascular leakage despite increasing systemic blood pressure. Inhalation of representative mast cell-derived mediators, histamine (2 mg/ml, 1 minute) or leukotriene D4 (5 micrograms/ml, 1 minute), produced significant microvascular leakage in all airways. L-NAME (10 mg/kg, intravenously) partially but significantly inhibited leukotriene D4-induced leakage, whereas histamine-induced leakage was not affected. These results suggest that endogenous nitric oxide acts to increase airway microvascular leakage after airway allergic reaction.

Mechanism of multiple aminoglycoside resistance of kasugamycin-producing Streptomyces kasugaensis MB273: involvement of two types of acetyltransferases in resistance to astromicin group antibiotics

The biochemical basis for the multiple resistance to aminoglycoside antibiotics (AGs) of kasugamycin-producing Streptomyces kasugaensis MB273 was studied. The strain was resistant to a wide range of deoxystreptamine (DOS)-containing AGs as well as astromicin (ASTM) group antibiotics. These AGs strongly inhibited in vitro polyU-directed polyphenylalanine-synthesis using ribosomes from the strain, while they were acetylated and inactivated by the MB273 cell free extract supplemented with acetyl-CoA. It seemed thus likely that the acetyltransferase activity played a critical role for the multiple AG resistance. The acetylation was selective to AGs with 2'-NH2, suggesting the involvement of aminoglycoside 2'-N-acetyltransferase, AAC (2'). Interestingly, the acetylation of istamycin B (ISM-B; an ASTM group AG) resulted in the formation of two different products (1-N-acetyl ISM-B and 2"-N-acetyl ISM-B) at a similar ratio. In this context, an AAC (2') gene cloned as an ISM-B resistance gene from the strain MB273 directed the conversion of ISM-B to only 1-N-acetyl ISM-B. It seemed likely that two types of AACs [AAC(2') and a novel one] were involved in the mechanism of resistance to ASTM group AGs.

Enzymatic 2'-N-acetylation of arbekacin and antibiotic activity of its product

Aminoglycoside antibiotics (AGs) with a free 2'-amino group were subjected to enzymatic N-acetylation using a cell free extract that contained an aminoglycoside 2'-N-acetyltransferase, AAC (2'), derived from a kasugamycin-producing strain of Streptomyces kasugaensis. TLC and antibiotic assay of the incubated reaction mixtures revealed that a modified compound retaining substantial antibiotic activity was formed from arbekacin (ABK), while modification of the other AGs resulted in the marked decrease in antibiotic activity. Structure determination following isolation from a large scale reaction mixture showed the modified ABK to be 2'-N-acetyl ABK. In addition, 2',6'-di-N-acetyl ABK was formed as a minor product. The same conversion also occurred with dibekacin (DKB) resulting in the formation of 2'-N-acetyl DKB and 2',6'-di-N-acetyl DKB. MIC determination showed antibacterial activity (1.56 approximately 3.13 micrograms/ml) of 2'-N-acetyl ABK against a variety of organisms. By contrast, 2'-N-acetyl DKB showed no substantial antibiotic activity. We believe 2'-N-acetyl ABK has the highest and broadest antibacterial activity, compared with known N-acetylated AGs.

Clinical results of treatment of triangular fibrocartilage complex tears by arthroscopic debridement

In order to determine indications for arthroscopic debridement and the management of triangular fibrocartilage complex (TFCC) tears, we reviewed 16 wrists retrospectively. The mean patient age was 30 years, with a range of 20 to 53 years. The follow-up period averaged 35 months. Two groups were identified: post-traumatic tears (n = 11) and degenerative tears (n = 5). The results of arthroscopic debridement were compared and analyzed based on the preoperative and postoperative evaluation of pain, range of motion, grip strength, return to work, patient acceptance, and complications. Failures were further evaluated to determine identifiable lesions or anatomic defects associated with poor results. Patients with positive ulnar variance and lunotriquentral interosseous ligament tears had a poor clinical outcome. Good results correlated with grip strength; all patients with post-traumatic TFCC tears had excellent results, while those with degenerative TFCC tears did poorly.

Involvement of endogenous tachykinins in LTD4-induced airway responses

Leukotriene D4-(LTD4) has been reported to cause tachykinin release from airway sensory nerves. However, the functional significance of endogenously released tachykinins in LTD4-mediated airway responses has not been fully clarified. The aim of this study was to investigate whether LTD4-induced airway responses are due, in part, to tachykinin release in guinea-pigs. Airway plasma exudation and bronchoconstriction were assessed by measuring extravasation of Evans blue dye and by mean pulmonary resistance (RL) in the presence of atropine (1 mg.kg-1 i.v.) and propranolol (1 mg.kg-1 i.v.), respectively. LTD4 (5 micrograms.mL-1 for 1 min) inhalation caused increase in plasma exudation and RL. Capsaicin pretreatment of animals to deplete sensory neuropeptides significantly inhibited LTD4-induced plasma exudation in the main bronchi, but not in the central (cIPA) and peripheral intrapulmonary airways (pIPA). Pretreatment with specific tachykinin neurokinin-1 (NK1)-receptor antagonists, FK 888 (10 mg.kg-1 i.v.) and CP 96345 (4 mg.kg-1 i.v.), also significantly reduced LTD4-induced plasma exudation in the main bronchi, and in the main bronchi and cIPA, respectively. However, these antagonists did not significantly affect the LTD4-induced increase in RL. In contrast, neurokinin-2 (NK2)-receptor antagonist, SR 48968 (0.3 mg.kg-1 i.v.), significantly inhibited the bronchoconstriction after LTD4-inhalation. These results suggest that leukotriene D4-induced bronchoconstriction and plasma exudation in guinea-pigs are, in part, due to tachykinin release from airway sensory nerves.

Hypereosinophilic syndrome with generalized myasthenia gravis

A patient with hypereosinophilic syndrome simultaneously had generalized myasthenia gravis. Ultrastructural and functional studies demonstrated an increase of the activated hypodense eosinophils. The eosinophilic cationic protein level in plasma and whole blood paralleled the severity of congestive heart failure. A high level of interleukin-5 was detected in both serum and in conditioned medium of T cells by interleukin-2 stimulation before therapy. The findings indicate that both diseases may be associated with a common T-cell abnormality.

Coexpression of thrombopoietin and c-mpl genes in human acute myeloblastic leukemia cells

Thrombopoietin (TPO) is a recently identified hematopoietic growth factor that is essential for the growth and development of megakaryocytes. We have previously shown that TPO induces proliferation of acute myeloblastic leukemia (AML) cells in vitro. In this study, we have examined the expression of TPO and its receptor c-mpl in a series of AML cases and human leukemia cell lines. The mRNA transcripts of TPO were detectable in 18 of 50 AML cases and in some myeloid leukemia cell lines (HEL, M07E and CMK) by means of reverse transcriptase polymerase chain reaction (RT-PCR). In addition, TPO transcripts were coexpressed with c-mpl transcripts in 10 of 50 AML cases and in HEL, M07E and CMK cells. With regard to the French-American-British (FAB) classification, coexpression OF TPO and c-mpl was observed with high frequency in AML cases of M7-type. Despite the TPO expression in a substantial fraction of leukemia cells, biological activity of TPO was not found in the conditioned medium that was obtained from cultivation of TPO mRNA-positive leukemia cells. These results suggest that TPO may not commonly participate in the abnormal growth of AML cells as an extracellular autocrine growth factor.

Extracorporeal shock wave lithotripsy in von Willebrand's disease

A renal calculus in a patient with von Willebrand's disease was successfully fragmented by extracorporeal shock wave lithotripsy (ESWL) with the administration of Haemate P. No serious bleeding was observed after ESWL. With supplementation of the missing von Willebrand's factor, ESWL may be applied to patients with this bleeding diathesis.

Effect of barnidipine on blood flow to major organs and renal function in anaesthetized dogs and spontaneously hypertensive rats

1. The effects of barnidipine on blood flow to major organs and on renal function were investigated in anaesthetized dogs and conscious spontaneously hypertensive rats (SHR), and the results were compared with those for nicardipine, nitrendipine, nisoldipine, manidipine and amlodipine. 2. In anaesthetized dogs, barnidipine (0.3-3 mu g/kg i.v.) dose-dependently decreased blood pressure and increased or preserved blood flow in the vertebral, coronary, femoral and renal arteries. The effect of barnidipine on blood flow was the most potent of the compounds tested. In conscious SHR, barnidipine (0.3-3 mg/kg p.o.) produced a dose-dependent antihypertensive effect and decreased renal vascular resistance. Barnidipine also dose-dependently increased urinary volume. The antihypertensive and diuretic effects of barnidipine were the most potent of the drugs tested. 3. In summary, barnidipine was shown to preserve or increase blood flow to major organs and to produce diuretic activity with a decrease in blood pressure. These findings suggest that barnidipine maintains or promotes renal function at antihypertensive doses.

PCR inhibition assay for DNA-targeted antibiotics

DNA amplification by polymerase chain reaction (PCR) should be inhibited if the target for amplification region in the template DNA is nicked or cut. Based on this premise, we established a sensitive and differential assay using PCR to detect antibiotics that act on DNA. After template lambda DNA (10 pg) was incubated with antibiotics (10 approximately 20 ng) at 37 degrees C for 30 minutes in a 5 microliters reaction volume, a PCR assay (10 microliters reaction volume; 25 approximately 30 cycles) was performed under the conditions we modified, resulting in amplification of a 500 bp fragment of lambda DNA which was monitored by agarose gel electrophoresis. Among the several antibiotics examined, the anthracyclines, bleomycin, D-cycloserine and mitomycin C clearly inhibited the PCR amplification reaction, whereas actinomycin D and ofloxacin did not. Preincubation of template DNA in the presence of Fe++ was necessary for bleomycin and cycloserine to exhibit marked inhibition of PCR. Mitomycin C exhibited the inhibition in the presence of DTT and Cu+. By contrast, non-DNA-acting antibiotics (200 ng) such as aminoglycosides, beta-lactams, and macrolides showed no inhibition. The PCR-amplified fragment from lambda DNA was not degraded by incubation with the antibiotics (20 ng) that inhibited PCR. Furthermore, ethylacetate extracts of the cultured broths of actinomycetes proved to be suitable as samples for this PCR inhibition assay.

Accurate frequency control of an internal-mirror He-Ne laser by means of a radiation-heating system

Radiation heating enables fast temperature control. I applied radiation heating to the oscillation frequency control of an internal-mirror He-Ne laser. The laser system has a fast frequency response, and its oscillation frequency is offset-locked in an iodine-stabilized He-Ne laser by a phase-lock loop circuit. The frequency discrepancy σ between the master and the slave lasers is less than 10(-13) with a 100-s gate time.

Growth response of acute myeloblastic leukemia cells to recombinant human thrombopoietin

Thrombopoietin (TPO) is a newly identified hematopoietic growth factor that stimulates both megakaryopoiesis and thrombopoiesis through its interaction with a specific cell surface receptor encoded by the c-mpl proto-oncogene. In an effort to investigate the effect of TPO on human myeloid leukemia cells, the expression of c-mpl and the proliferative response to recombinant human (rh) TPO were investigated in a series of patients with acute myeloblastic leukemia (AML). Of 50 cases of AML, the c-mpl mRNA was detectable by means of Northern blot analysis in 26 cases, and the in vitro treatment with rhTPO led to proliferation of AML cells in 22 cases. The c-mpl expression and proliferative response to rhTPO was observed in all subtypes of AML and did not correlate with French-American-British classification, whereas all cases of M7-type AML cells expressed c-mpl and proliferated in response to rhTPO. Furthermore, rhTPO-induced proliferation of AML cells was augmented with the addition of interleukin-3 (IL-3), IL-6, stem cell factor, or granulocyte-macrophage colony-stimulating factor. These results suggested that c-mpl may be functional in terms of supporting proliferation of various types of AML cells and that TPO may contribute, at least in part, to abnormal growth of the cells, especially in combination with other hematopoietic growth factors.

The Sauvé-Kapandji procedure for osteoarthritis of the distal radioulnar joint

The Sauvé-Kapandji procedure has been performed in 15 patients with primary and secondary osteoarthritis of the distal radioulnar joint. The average age of the patients was 45 years (range, 31-63 years). There were 12 men and 3 women. The follow-up period averaged 2 years and 11 months. Postoperative pain relief was good in all wrists. The preoperative range of motion of the wrist joint averaged 50 degrees extension and 44 degrees flexion. Forearm motion averaged 66 degrees pronation and 64 degrees supination. Postoperatively, the range of motion improved to 55 degrees extension and 51 degrees flexion at the wrist and forearm motion improved to 78 degrees pronation and 82 degrees supination. Although all wrists also showed an increased grip strength and improved range of motion over preoperative values, these did not have statistical significance. Postoperative x-ray evaluation showed an unstable proximal stump and radioulnar convergence in 12 wrists. Our clinical and x-ray film findings suggest that the Sauvé-Kapandji procedure is a satisfactory procedure for patients with osteoarthritis of the distal radioulnar joint.

Chronic allergen exposure enhances cholinergic neurotransmission in sensitized guinea-pigs

Airway hyperresponsiveness in asthmatic patients may be related to cholinergic hyperresponsiveness. In this study, we examined whether chronic allergen exposure induces cholinergic hyperresponsiveness in ovalbumin (OA) sensitized guinea-pig airways. Three weeks after active sensitization, ovalbumin (0.03%, for 3 min, challenged group) or saline inhalation (control group) was repeated every day for 4 weeks. Cholinergic responses were assessed by isometric tracheal contraction after electrical field stimulation (EFS) or exogenously applied acetylcholine (ACh). The contractions were expressed as a percentage of the maximum response to ACh (10(-3) M) (AChmax). We calculated the effective frequencies producing 25% of AChmax (EF25) from frequency-response curves. EFS-induced contractile responses were significantly enhanced in the challenged group (logEF25 = 0.66 +/- 0.08 (mean +/- SEM)) compared with the control group (logEF25 = 1.12 +/- 0.16). In contrast, exogenous ACh-mediated contractile tracheal responses were almost the same in both groups. We conclude that repeated allergen inhalation causes cholinergic airway hyperresponsiveness, presumably due to the facilitation of cholinergic neurotransmission. This mechanism may be involved in the airway hyperresponsiveness in asthmatic airways.

Chronic allergen exposure enhances cholinergic neurotransmission in sensitized guinea-pigs

Airway hyperresponsiveness in asthmatic patients may be related to cholinergic hyperresponsiveness. In this study, we examined whether chronic allergen exposure induces cholinergic hyperresponsiveness in ovalbumin (OA) sensitized guinea-pig airways. Three weeks after active sensitization, ovalbumin (0.03%, for 3 min, challenged group) or saline inhalation (control group) was repeated every day for 4 weeks. Cholinergic responses were assessed by isometric tracheal contraction after electrical field stimulation (EFS) or exogenously applied acetylcholine (ACh). The contractions were expressed as a percentage of the maximum response to ACh (10(-3) M) (AChmax). We calculated the effective frequencies producing 25% of AChmax (EF25) from frequency-response curves. EFS-induced contractile responses were significantly enhanced in the challenged group (logEF25 = 0.66 +/- 0.08 (mean +/- SEM)) compared with the control group (logEF25 = 1.12 +/- 0.16). In contrast, exogenous ACh-mediated contractile tracheal responses were almost the same in both groups. We conclude that repeated allergen inhalation causes cholinergic airway hyperresponsiveness, presumably due to the facilitation of cholinergic neurotransmission. This mechanism may be involved in the airway hyperresponsiveness in asthmatic airways.

Molecular cloning and chromosomal mapping of a bone marrow stromal cell surface gene, BST2, that may be involved in pre-B-cell growth

Bone marrow stromal cells regulate B-cell growth and development through their surface molecules and cytokines. In this study, we generated a mAb, RS38, that recognized a novel human membrane protein, BST-2, expressed on bone marrow stromal cell lines and synovial cell lines. We cloned a cDNA encoding BST-2 from a rheumatoid arthritis-derived synovial cell line. BST-2 is a 30- to 36-kDa type II transmembrane protein, consisting of 180 amino acids. The BST-2 gene (HGMW-approved symbol BST2) is located on chromosome 19p13.2. BST-2 is expressed not only on certain bone marrow stromal cell lines but also on various normal tissues, although its expression pattern is different from that of another bone marrow stromal cell surface molecule, BST-1. BST-2 surface expression on fibroblast cell lines facilitated the stromal cell-dependent growth of a murine bone marrow-derived pre-B-cell line, DW34. The results suggest that BST-2 may be involved in pre-B-cell growth.

Genetic basis of the silent phenotype of serum butyrylcholinesterase in three compound heterozygotes

Three Japanese patients showed very low butyrylcholinesterase activity in their sera and appeared to be homozygous for silent genes for butyrylcholinesterase. From DNA analysis, all three patients were compound heterozygotes: GGA(Gly) to CGA(Arg) at codon 365 (G365R) and TTC(Phe) to TCC(Ser) at codon 418 (F418S) in patient 1, G365R and CGT(Arg) to TGT(Cys) at codon 515 (R515C) in patient 2 and ACT(Thr) to CCT(Pro) at codon 250 (T250P) and AGA(Arg) to TGA(Stop) at codon 465 (R465X) in patient 3. The K-variant, GCA(Ala) to ACA(Thr) at codon 539, was also found in patients 1 and 2. Simple identification methods for all the mutations were developed and applied to family analysis and control individuals. The mutant alleles (with silent gene and K-variant) were segregated as predicted by theory in pedigrees of patients 1 and 2. Four of the mutations, F418S, R515C, T250P and R465X, were initially discovered in Japan and genetic heterogeneity among the human population for the butyrylcholinesterase gene was suggested.

A case of beriberi accompanying short bowel

A case of beriberi based on short bowel is reported. A 4 year old girl, who underwent a resection of the intestine when a neonate and has had a short bowel, manifested beriberi despite eating normal Japanese food. Considering that she has had no dislikes of foods, and her family members, who have eaten meals similar to hers have been healthy, beriberi is considered in this case to have developed mainly through hypoabsorption of vitamin B1. This patient has responded well to vitamin B1 therapy with a relatively slow recovery in neural functions. Although it has not been confirmed whether short bowel syndrome is prone to be accompanied by beriberi, special attention should be given to vitamin B1 in short bowel syndrome patients.

Hemiresection-interposition arthroplasty for osteoarthritis of the distal radioulnar joint

Hemiresection-interposition arthroplasty of the distal radioulnar joint has been carried out in 12 men. The indication was osteoarthritis with an intact triangular fibrocartilage, or when the fibrocartilage could be reconstructed. The average age was 41 years and average follow up for 53 months. In all the patients, there was relief of pain and a significant increase in movement and in grip strength.

Hypoplastic left heart syndrome with a single coronary artery originating from the pulmonary artery

A newborn male infant with hypoplastic left heart syndrome due to mitral and aortic atresia died on the third day of life. Autopsy revealed a single coronary artery originating from the pulmonary artery, reversed coarctation of the aorta, a coronary sinus type atrial septal defect and stenosis of the left subclavian artery. To our knowledge, hypoplastic left heart syndrome associated with a single coronary artery originating from the pulmonary artery has never been reported in the English or Japanese literature. This may be the first such case.

ADP ribosyl cyclase activity of a novel bone marrow stromal cell surface molecule, BST-1

Human BST-1, a bone marrow stromal cell surface molecule, is a GPI-anchored protein that facilitates the growth of pre-B cells. The deduced amino acid sequences of human and mouse BST-1 show around 30% homology with those of CD38 and Aplysia ADP ribosyl cyclase. Therefore, like CD38, BST-1 might possess ADP ribosyl cyclase activity. Here, we report the establishment of a stable transformant CHO cell line, which secretes truncated human soluble BST-1, and show that purified soluble BST-1 displays both ADP ribosyl cyclase and cADPR hydrolase activities.