Interaction between NUDT15 and ABCC4 variants enhances intolerability of 6-mercaptopurine in Japanese patients with childhood acute lymphoblastic leukemia.

6-Mercaptopurine (6-MP) is a main component of childhood acute lymphoblastic leukemia (ALL) treatment. Some candidate gene variants are associated with its toxicities, but the major variants and effects of combined variants remain unclear. We used Cox regression analysis to evaluate the time-dependent association between candidate variants and the cumulative incidence of 6-MP intolerability in 95 Japanese patients. The major risk factors for severe leukopenia were ABCC4 rs3765534, NUDT15 rs116855232 and rs186364861 in multi-covariate analysis (P<0.05). NUDT15 intermediate activity variant, that is, heterozygous rs116855232 or rs186364861 variant, and the ABCC4 rs3765534 variant showed leukopenia more frequently than either variant alone. All patients with both the intermediate activity NUDT15 variant and the ABCC4 rs3765534 variant suffered from leukopenia, and 57.1% patients required 50% protocol dose by day 168. These data indicate that NUDT15 and ABCC4 are major factors for 6-MP intolerability and that the interaction between these variants enhances intolerability to 6-MP.

Multidrug resistance protein 4 (MRP4) polymorphisms impact the 6-mercaptopurine dose tolerance during maintenance therapy in Japanese childhood acute lymphoblastic leukemia.

Multidrug resistance protein 4 (MRP4) is involved in the efflux of nucleoside derivatives and has a role in the determination of drug sensitivity. We investigated the relationship between MRP4 genetic polymorphisms and doses of the 6-mercaptopurine (6-MP) and methotrexate. Further, we evaluated the frequency of therapeutic interruption during maintenance therapy in Japanese children with acute lymphoblastic leukemia (ALL). Ninety-four patients received an initial 6-MP dose in the range of 30-50 mg m(-2) in this analysis. Patients with homozygous variant allele in any of MRP4 G2269A, C912A and G559T required high frequency of 6-MP dose reduction compared with non-homozygous individuals. Average 6-MP dose for patients with homozygous variant allele on either MRP4 or inosine triphosphate pyrophosphatase was significantly lower than that for patients with non-homozygous variant allele during maintenance therapy (30.5 versus 40.0 mg m(-2), P=0.024). Therefore, MRP4 genotyping may be useful for personalizing the therapeutic dose of 6-MP during the ALL maintenance therapy in Japanese.

Vestibular function and vasopressin.

OBJECTIVE: To investigate the relation between the vestibular system and vasopressin (AVP). MATERIAL AND METHODS: We examined the effects of electrical and caloric vestibular stimulation on plasma AVP levels in anesthetized rats. Plasma AVP levels of patients with intractable Ménière's disease who were subjected to endolymphatic drainage and steroid instillation surgery (EDSS) or intratympanic gentamicin (GM) injection were measured before and after these interventions. RESULTS: Electrical vestibular stimulation increased plasma AVP levels in a current intensity-dependent manner. Plasma AVP levels were also increased by caloric stimulation with cold water. Plasma AVP levels decreased rapidly after EDSS, and were maintained at a low level even 6-12 months following EDSS or intratympanic GM injection. CONCLUSIONS: Vestibular activation or inhibition-induced imbalance of intervestibular activities increased plasma AVP levels in rats. Therefore, vestibular disorder would seem to increase plasma AVP and thus worsen endolymphatic hydrops. EDSS rapidly decreased plasma AVP and would seem to reduce hydrops. Inhibition of vertigo spells by EDSS or intratympanic GM injection would reduce a possible stress response, resulting in a decrease in plasma AVP levels a long time after the treatments. This resultant decrease in AVP would beneficially inhibit the formation and/or maintenance of hydrops and thus prevent vertigo spells.

Human beta-defensin-2 induction in Helicobacter pylori-infected gastric mucosal tissues: antimicrobial effect of overexpression.

The objective of this study was to understand more of the innate immune response to Helicobacter pylori by determining the expression of human beta-defensin-2 (hBD-2) in various gastric mucosal tissues and MKN45 gastric cancer cells with or without H. pylori. Semi-quantitative TaqMan RT-PCR and immunohistochemistry were carried out. The antimicrobial effects of a transfected hBD-2 gene against H. pylori were also evaluated. The results showed that hBD-2 was expressed in inflamed gastric mucosal tissues with H. pylori infection, but not in the absence of H. pylori infection. Expression was also detected in gastric cancers in patients with H. pylori infection. Expression was induced in the MKN45 gastric cancer cell line by H. pylori in a manner dependent on the abundance of bacteria. hBD-2-transfected 3T3J2-1 cells secreted hBD-2 protein into the culture medium and this protein inhibited growth of H. pylori completely. The results suggest that hBD-2 may be involved in the pathophysiology of H. pylori-induced gastritis.

Comparison of arbitrarily primed-polymerase chain reaction and pulse-field gel electrophoresis for characterizing methicillin-resistant Staphylococcus aureus.

AIMS: The aim of this study was to analyse genotypes for clinical isolates of methicillin-resistant Staphylococcus aureus (MRSA), including hetero-vancomycin-resistant Staph. aureus (VRSA), at a Japanese university hospital. METHODS AND RESULTS: Seventy-eight clinical isolates of MRSA were analysed by arbitrarily primed-polymerase chain reaction (AP-PCR) using ERIC2 primer and by pulse-field gel electrophoresis (PFGE) following SmaI digestion. Analyses of the nine genotypes and 28 subtypes defined by PFGE, and of the three genotypes and 22 subtypes defined by AP-PCR, both facilitated epidemiological tracing. Used in combination, AP-PCR and PFGE provided more precise classification than the use of a single genotyping method. The six hetero-VRSA isolates were classified into four genotypes defined by the combination of both methods, but these genotypes contained non-VRSA isolates. CONCLUSIONS: The results suggest that both PFGE and AP-PCR are useful in discriminating MRSA, but not hetero-VRSA, isolates for epidemiological analysis. SIGNIFICANCE AND IMPACT OF THE STUDY: Combining the results of PFGE with the results of AP-PCR can provide more detail differentiation of MRSA and hetero-MRSA isolates than either method alone.

[Endolymphatic sac drainage and steroid-instillation surgery (EDSS) for intractable Meniere's disease].

Endolymphatic sac surgery is one of the most widely accepted techniques used to treat intractable Meniere's disease. To improve this surgery, we developed the following techniques: A simple mastoidectomy was used to expose the endolymphatic sac between the sigmoid sinus and inferior margin of the posterior semicircular canal. The sac was opened and filled with a mass of prednisolone. A bundle of absorbable gelatin films was then inserted into the sac lumen to expand it, followed by gelatin sponges dipped in a high concentration of dexamethasone. Long-term results (17-32 months) in 20 patients with intractable Meniere's disease treated with endolymphatic sac drainage and steroid-insertion surgery (EDSS) showed that definitive spells were completely controlled in 15 of 20 cases (75%); all reports of vertigo decreased; hearing improved in 12 of 20 cases (60%); and annoyance due to tinnitus decreased in 15 of 20 cases (75%). Steroids directly instilled into the endolymphatic cavity may thus be more effective with the diseased inner ear organs than those applied via any other route. Draining of endolymphatic fluid at the sac into the mastoid cavity also contributed to these satisfactory EDSS results.

Augmentation of megakaryocytopoiesis within the hematopoietic microenvironment of human granulocyte colony-stimulating factor transgenic mice.

OBJECTIVE: Megakaryocytopoiesis was dramatically augmented in human granulocyte colony-stimulating factor transgenic mice (G-Tg) compared to littermates. We examined the characteristics of megakaryocytes and megakaryocyte progenitor cells in these mice. MATERIALS AND METHODS: The numbers of colony-forming unit megakaryocytes (CFU-MK) and megakaryocytes in hematopoietic organs were counted. The megakaryocytes of G-Tg were examined ultrastructurally, and bone marrow transplantation studies using congenic G-Tg (Ly5.2) and C57BL/6 (Ly5.1) were performed. The number of day-14 colony-forming unit spleen (CFU-S) that contained megakaryocytes in [Ly5.1 > G-Tg] and [G-Tg > Ly5.1] mice also was counted. RESULTS: The number of CFU-MK increased markedly in the spleen, bone marrow, and peripheral blood. The number of megakaryocytes in the spleen and bone marrow also were increased in G-Tg mice. Ultrastructural analyses revealed that megakaryocytes in G-Tg mice were immature. Bone marrow transplantation studies of [Ly5.1 > G-Tg] mice resulted in a significantly increased number of megakaryocytes compared to [G-Tg > Ly5.1] mice. The number of day-14 CFU-S that contained megakaryocytes was increased markedly in [Ly5.1 > G-Tg] mice compared to [G-Tg > Ly5.1] mice. In vitro differentiation of megakaryocytes in [Ly5.1 > G-Tg] mice was induced by interleukin-11 and thrombopoietin. CONCLUSION: The results showed that the hematopoietic marrow microenvironment of G-Tg is important in augmenting megakaryocytopoiesis. [Ly5.1 > G-Tg] mice are potentially useful as a source of murine megakaryocytes and their progenitors.

Large-scale cDNA analysis of the maternal genetic information in the egg of Halocynthia roretzi for a gene expression catalog of ascidian development.

The ascidian egg is a well-known mosaic egg. In order to investigate the molecular nature of the maternal genetic information stored in the egg, we have prepared cDNAs from the mRNAs in the fertilized eggs of the ascidian, Halocynthia roretzi. The cDNAs of the ascidian embryo were sequenced, and the localization of individual mRNA was examined in staged embryos by whole-mount in situ hybridization. The data obtained were stored in the database MAGEST (http://www.genome.ad.jp/magest) and further analyzed. A total of 4240 cDNA clones were found to represent 2221 gene transcripts, including at least 934 different protein-coding sequences. The mRNA population of the egg consisted of a low prevalence, high complexity sequence set. The majority of the clones were of the rare sequence class, and of these, 42% of the clones showed significant matches with known peptides, mainly consisting of proteins with housekeeping functions such as metabolism and cell division. In addition, we found cDNAs encoding components involved in different signal transduction pathways and cDNAs encoding nucleotide-binding proteins. Large-scale analyses of the distribution of the RNA corresponding to each cDNA in the eight-cell, 110-cell and early tailbud embryos were simultaneously carried out. These analyses revealed that a small fraction of the maternal RNAs were localized in the eight-cell embryo, and that 7.9% of the clones were exclusively maternal, while 40.6% of the maternal clones showed expression in the later stages. This study provides global insights about the genes expressed during early development.

[Plication of the sinotubular junction for aneurysm of the ascending aorta associated with aortic regurgitation: a case report].

A 63-year-old woman with aneurysm of the ascending aorta associated with AR due to dilatation of the sinotubular junction (STJ) and with poor LV function, who did not have Marfan syndrome, underwent a plication of the STJ and replacement of the ascending aorta. In operation, we simultaneously performed the plication of dilated STJ (60 mm) and the replacement of ascending aorta using a 26 mm Woven Dacron graft. Post-operative angiogram (1 POM) showed no aortic regurgitation and good recovery of the LV function. This procedure is less invasive, and indicated for patients without significant elongation or thickening of the aortic valve, especially when the patients have higher risk.

Midcalf ultrasonography for the diagnosis of ruptured Baker's cysts.

Clinically significant and palpable enlargement of the gastrocnemio-semimembranosus bursa is known as a Baker's cyst. Baker's cysts may rupture, resulting in a swollen, painful leg that is clinically indistinguishable from acute deep vein thrombosis. For this reason, ruptured Baker's cysts are sometimes called pseudothrombophlebitis. The purpose of this study was to determine the incidence of ruptured Baker's cysts, and to evaluate the role of ultrasonography in the diagnosis of this condition. The hospital records of 106 patients (43 men and 63 women) who were referred to the vascular surgical department at Saitama Medical Center with unilateral or bilateral swollen legs between June 1997 and June 2000 were reviewed retrospectively. The total number of affected limbs was 125, being 52 right legs and 73 left legs. Deep vein thrombosis was the most common cause of swollen legs, being diagnosed in 44.8%. No specific anatomical derangement was found in 39 limbs (31.2%), and these were defined as idiopathic. Lymphedema was also common, being diagnosed in 16 limbs. Ruptured Baker's cysts were observed in three limbs, with an incidence of 2.4%. In all of these patients, a large hypoechoic space was seen behind the calf muscles and this sonolucent area was easily detected by a conventional scanner, being pathognomonic of a ruptured Baker's cyst.

[Light-wand (Trachlight) guided nasotracheal intubation].

We report that Trachlight-guided nasotracheal intubation might be achieved successfully and traumatically without removal of a stiff internal stylet. Endotracheal tube was mounted on a Trachlight with the stylet in position and bent to form a less sharp curvature than a right angle, namely 40-60 degree, at 7 cm proximal to the endotracheal tube tip. Forty-six patients scheduled for nasal intubation were studied to measure the intubation time and the success rate with the use of Trachlight. The tracheas were successfully intubated in 89% of patients. We suggest that Trachlight-guided nasotracheal intubation could be clinically feasible without traumatic complication when applied with a stiff stylet in position and this approach is a useful method for nasal intubation.

[An electrophysiological study of ropivacaine on excised cervical vagus nerves of rabbit].

Ropivacaine, a new long acting local anaesthetic of amide type is structurally related to mepivacaine and bupivacaine. This study was designed to compare the in vitro potency and neurotoxicity of ropivacaine with those of other commercially available local anaesthetics using an isolated rabbit vagus nerve model. Ropivacaine dose-dependently suppressed the evoked compound action potentials of A beta nerve and C nerve components. Minimum concentration of ropivacaine for producing complete suppression of the compound action potentials of all components was 0.008%. Electron microscopic observation showed that ropivacaine did not destroy any peripheral nervous structures in concentrations up to 0.75%. When the neurotoxic effect of ropivacaine was compared, in terms of risk ratio (clinically used concentration/concentrations producing 2 hr irreversible block), with that of commercially available local anesthetics, the rank oder was dibucaine, tetracaine, lidocaine, bupivacaine and ropivacaine.

Plasma endothelin and LH-RH, LH, FSH, prolactin, progesterone, 17alpha-hydroxyprogesterone, estrone, 17beta-estradiol, delta4-androstenedione, testosterone, active renin, angiotensin-II and ANP levels in blood and LH, estrone and 17beta-estradiol and pregnanediol levels in urine of normal cycling women.

In order to investigate the endothelin (ET) levels and their relationship to various hormones during the menstrual cycle, we measured endothelin-1, -2 and -3 (ET-1, -2 and -3), big ET-1 and big ET-3 levels in 27 normally cycling women (mean age 27 years). Simultaneous determination of luteinizing hormone-releasing hormone (LH-RH), luteinizing hormone (LH), follicle-stimulating hormone (FSH), prolactin, progesterone, 17alpha-hydroxyprogesterone (17-OHP), estrone, 17beta-estradiol, delta4-androstenedione, testosterone, active renin, angiotensin-II (A-II) and atrial natriuretic peptide (ANP) in blood, and LH, estrone and 17beta-estradiol and pregnanediol levels in urine was made in the same 27 women. The levels of ET-2 in plasma were found to be 20% of those of ET-1. In addition, ET-1 levels were measured in the endometrium of the normal uterus. Plasma ET-1 and ET-3 levels fluctuated during the menstrual cycle, with a peak at the luteal phase, but showed only a negative relationship (p < 0.01) to each other at the menstrual phase, whereas big ET-1 and big ET-3 levels showed no significant changes. Plasma ET-1 and ET-3 levels showed no significant relationship to the big ETs. As for the relationship to other hormones, plasma ET-3 had a negative relationship (p < 0.01) to prolactin and a positive correlation (p < 0.01) with ANP during the entire menstrual cycle. Plasma ET-1 and ET-3 showed a partial positive or negative correlation to LH, FSH, prolactin and ANP levels, depending upon the cycle phase, whereas plasma ETs and big ETs were unrelated to other hormones in the blood, and LH, estrone, 17beta-estradiol and pregnanediol in the urine throughout the menstrual cycle. At each menstrual stage, plasma ET-3 levels were more significantly related to LH, FSH, prolactin and ANP than ET-1, indicating a closer relationship between ET-3 and these circulating hormones during the menstrual cycle. The ET-1 level showed no significant change in the endometrium during the menstrual cycle.

[Equilibration period for PaO2 following alteration of FIO2 in mechanically ventilated patients].

To determine arterial oxygen tension (PaO2) in mechanically ventilated patients, we repeatedly measured arterial blood gas (ABG) to examine changes in PaO2 until equilibration following alteration of fractional concentrations of oxygen in inspired gas (FIO2). Forty anesthetized patients with normal arterial oxygenation were randomly assigned to one of four groups. Group 1 (n = 10): Arterial blood samples were drawn every one minute during a 15-min period of equilibration after change of FIO2 from 1.0 to 0.21. Then FIO2 was returned to 1.0 and the similar sampling was repeated. Group 2 (n = 10): The protocol was same as in Group 1 except for FIO2 targeted for 0.8 and 0.4. Group 3 (n = 10): Blood sampling was every two minutes during a 14-min period and repeated while FIO2 was altered as in Group 1. Group 4 (n = 10): The protocol was same as in Group 3 except for the target FIO2 similar to Group 2. PaO2 was stabilized in 4 min at earliest and in 6 min at latest after change of FIO2 in every settings of this study. In mechanically ventilated patients with normal arterial oxygenation, PaO2 could be stabilized after a 6-min period of equilibration following alteration of FIO2.

[Management of the acoustic tumor in an only/better hearing ear].

Because profound bilateral hearing impairment is a catastrophic event, the management and care of an individual with an 8th nerve lesion in an only/better hearing ear remains a significant challenge for both patient and physician. Current options regarding the treatment of the acoustic tumor in an only/better hearing ear include: observation, attempted hearing preservation surgery and stereotactically guided radiation therapy. In this article, we present 3 cases of acoustic tumor within the internal auditory canal in an only/better hearing ear diagnosed by gadolinium-enhanced MRI and discuss the recommendations, especially observation, available in the care of these cases. In one patient, hearing disturbance caused by the tumor in a better hearing ear made the patient quite depressive and desperate. One of the most important consideration is for the physician to provide the patient with adequate informed consent regarding the possibility of profound bilateral hearing loss caused by either the natural growth or surgical removal of the tumor in the future, and alternative methods of communication with others such as: hearing aid and lip reading, cochlear implant and brainstem implant.

[Anesthetic management for a patient with spondyloepiphyseal dysplasia congenita].

An 11-year-old girl with spondyloepiphyseal dysplasia congenita in the spine was scheduled for virectomy under general anesthesia. She had slight scoliosis in the thoracic and lumbar spine, moderate funnel chest and slight thoracic kyphosis. Preoperative laboratory data were within normal range and her intelligence was normal. Her Mallanpathi's score, however, was Grade 3 and effective mandibular length/posterior depth of mandible ratio was 3.48 on the lateral view of head X-ray. From these data, difficult intubation was expected. Although anesthesia was induced uneventfully using thiamylal and vecuronium, her vocal cord was not visualized under laryngoscope. Using cricoid pressure procedure, slightly left-shifted vocal cord was exposed. However a 26 Fr. size endotracheal tube without cuff was too large and finally a 22 Fr. tube was inserted. During the operation patient's general condition was stable and the operation was finished without any episodes. She did not have any complications in the postoperative period. In a case of SDC, pathological changes in laryngotracheal resion should be examined and evaluated preoperatively and difficult intubation should also be always taken into account.

A case of Currarino triad with familial sacral bony deformities.

We describe a male patient presenting with Currarino triad: a recto-urethral fistula, sacral bony deformity, and a presacral teratoma. Clinical screening of his family revealed three additional cases with incomplete forms of this association. Cytogenetic findings in the patient and his mother were normal. This case suggests that the occurrence of an anorectal malformation together with a sacral bony deformity should raise a physician's index of suspicion for associated presacral tumors, and that screening of the patient's family members with sacral radiographs is necessary.

[Vestibular symptoms and ENG findings during periods of convalescence after endolymphatic sac drainage and steroid-instillation surgery (EDSS)].

Understanding the appearance of vestibular symptoms during periods of convalescence after surgery for the treatment of Meniere's disease is important for determining when a patient can return to work as well as the long-term results of the operation. We have treated 20 cases of intractable Meniere's disease with endolymphatic sac drainage & steroid-instillation surgery (EDSS) [Kitahara T, et al., Ann Otol Rhlnol Laryngol in press, 2000] and observed the subjective symptoms and objective vestibular findings using electronystagmogram (ENG) during the subsequent period of convalescence. The average postoperative durations of subjective static and evoked vestibular symptoms were 1.7 and 6.7 days, respectively. Those of spontaneous, positional and positioning nystagmus observed using ENG were 1.2, 2.0 and 7.9 days, respectively. In cases with a long history of Meniere's disease, postoperative static vestibular sensation and positional nystagmus lasted significantly longer than in cases with short histories. In cases with poorly developed temporal bony pneumatization in the area behind the posterior semicircular canal, postoperative evoked vestibular sensations and positioning nystagmus lasted significantly longer than in cases with well developed temporal bony pneumatization. Vestibular symptoms resulting from direct invasion during EDSS were considered to be slighter than those resulting from vestibular neurectomy or gentamicin treatment and almost the same as those resulting from endolymphatic sac surgery.