Successful control of an outbreak of GES-5 extended-spectrum β-lactamase-producing Pseudomonas aeruginosa in a long-term care facility in Japan

BACKGROUND

Little is known about multidrug-resistant Pseudomonas aeruginosa (MDRP) outbreaks in long-term care facilities (LTCFs).

AIM

To describe an MDRP outbreak in an LTCF and to clarify risk factors for MDRP acquisition.

METHODS

Patients who were positive for MDRP at an LTCF from January 2013 to January 2014 were analysed. A descriptive analysis, a case-control study, and a microbiological analysis were performed.

FINDINGS

A total of 23 MDRP cases were identified, 16 of which were confirmed in sputum samples. Healthcare workers were observed violating hand hygiene procedures when performing oral, wound, and genital care. Nasogastric tube and oxygen mask use was associated with MDRP acquisition in the respiratory tract, which might have been confounded by poor hand hygiene. Sharing unhygienic devices, such as portable oral suction devices for oral care, and washing bottles and ointments for wound and genital care with inadequate disinfection could explain the transmission of MDRP in some cases. Isolates from 11 patients were found to be indistinguishable or closely related by pulsed-field gel electrophoresis and harbouring the blaGES-5 gene. Subsequent enhanced infection control measures were supported by nearby hospitals and a local public health centre. No additional cases were identified for a year after the last case occurred in January 2014.

CONCLUSION

An outbreak of MDRP with an antimicrobial resistance gene, blaGES-5, occurred in a Japanese LTCF. It was successfully controlled by enhanced infection control measures, which neighbouring hospitals and a local public health centre supported.

Half-value layer measurement: simple process method using radiochromic film

Although the half-value layer (HVL) is one of the important parameters for QA and QC, constant monitoring has not been performed because the measurements using an ionization chamber (IC) are time-consuming and complicated. To solve these problems, the use of radiochromic film (GAFCHROMIC XR TYPE R: GAF-R) with step-shaped aluminum (Al) filters, referred to herein as the simple process method, has been developed. The measurement X-ray tube voltages were 120 kV, 100 kV, and 80 kV. The Al filter area, the full exposure area, and the unexposed area were set on the GAF-R so as to obtain correct data. The HVL was evaluated using the density attenuation ratio. The HVLs obtained using the GAF-R and an 1C dosimeter were compared. HVLs with X-ray tube voltages of 120 kV, 100 kV, and 80 kV using the GAF-R were 4.10 mm, 3.55 mm and 2.97 mm, respectively. The difference ratios of the HVLs using the GAF-R and the IC were 1.2%, 7.6%, and 10.0%, respectively. The HVL at 120 kV can be routinely and quickly measured using the simple process method. Therefore, an IC dosimeter is not needed for HVL measurements for QA and QC. However, the HVL measurements of low energy (100 kV and 80 kV) need attention.

[Subtraction image for dynamic liver MRI using free breath-hold at functional residual capacity: a clinical trial]

PURPOSE

Dynamic liver MRI images have been obtained under expiration breath holding (BH). However, problems with obtaining reproducible liver positions often observed. This study investigated ways to improve the reproducibility of liver position on dynamic liver MRI.

MATERIALS AND METHODS

After giving informed consent, 60 patients (32 males and 28 females, ages 33-85, median age 69) were examined by liver dynamic MRI under two types of BH. The BH phases were voluntary expiration (VE) phase without any explanations and functional residual capacity (FRC) phase after careful explanation was provided. Plain images, arterial phase images, portal phase images and parenchymal phase images were obtained. For statistical evaluation of reproducibility, the area of the 2nd or 3rd images from top of the liver was measured in each phase using a threshold value of half maximum. Misregistration areas were calculated by finding the remainder of the liver area in the plain-arterial (Pl-A) phase, arterial-portal (A-Po) phase, plain-parenchymal (Pl-Pa) phase. Contingency table analysis was done due to the misregistration was occurred or not.

RESULTS

Misregistration of liver image on the VE and the FRC of three phase types were statistical significant on the Pl-A (p < 0.01), on the A-Po (p < 0.01) and on the Pl-Pa (p < 0.05), respectively.

CONCLUSION

The FRC phase following careful explanation of the BH provided significantly improved reproducibility of liver position on dynamic liver MRI. Therefore, precise subtraction images could be obtained for routine clinical examinations without slice matching.

[Surgical treatment of thymic carcinomas]

Five cases of surgically treated thymic carcinoma are reported. The patients (4 men and a woman) ranged in age from 46 to 76 years old with a mean of 64.6. Four patients were asymptomatic and an abnormal shadow on X-ray films was noted. One remaining patient suffered from hoarseness. One patient had stage II disease and the others had stage III. Surgical tumor resection was performed in all cases. Only 1 patient among the 5 underwent a successful complete resection. Histological examinations of the resected specimens revealed squamous cell carcinoma of thymus. Four specimens were poorly differentiated and 1 is moderately differentiated carcinoma. All patients received radiation therapy post operatively. Three patients are alive without any recurrence 6, 8 and 109 months after the surgery. Thymic carcinomas are frequently invasive or metastatic at the time of diagnosis. But poorly differentiated group, in squamous cell carcinoma, mucoepidermoid carcinoma and besaloid carcinoma, are characterized by a low incidence of local recurrence and distant metastasis. They also have a good sensitivity for the radiation. Therefore complete surgical resection combined with postoperative radiation therapy should be a choice in treating thymic carcinomas. We considered that complete resection and postoperative radiation therapy is a curative therapy for thymic carcinomas.

Molecular dissection of alpha- and dense-core granule secretion of platelets

Upon activation, platelets release many active substances stored in alpha- and dense-core granules. However, the molecular mechanisms governing the regulated exocytosis are not yet fully understood. We have established an assay system using streptolysin-O-permeabilized platelets to analyze the Ca2+-induced secretions of von Willebrand factor stored in alpha-granules and [3H]5-hydroxytryptamine (5-HT) in dense-core granules. Using the assay, we found that small GTPase Rab4 regulates alpha-, but not dense-core, granule secretion in platelets. Furthermore, we purified a cytosolic essential protein and currently are analyzing its function.

[Studies on kinetic viscoelasticity of slow muscle fibers--2. Dynamic stiffness changes studied by quick release method and frequency response method]

PURPOSE

To evaluate the mechanical properties of slow fibers and fast fibers which make up the extraocular muscles in rabbits.

SUBJECTS AND METHOD

I studied the contractile properties and viscoelastic properties of the superior rectus muscle(SR) and the retractor bulbi muscle (RB) of rabbits using the quick release method and the frequency response method.

RESULTS

In the quick release method, isometric tension transients were slower in the SR than in the RB. In the frequency response method, the muscle length is perturbed sinusoidally to measure kinetic viscoelasticity. In resting muscle, dynamic stiffness was not changed with increasing frequency. In contracted muscle, dynamic stiffness was increased with increasing frequency, and the rate of increase was greater in the SR than in the RB.

CONCLUSION

It was concluded that the viscoelasticity of the activated cross bridge is greater in slow fibers than in fast fibers.

[Examination of eye position after strabismus surgery in Kawasaki Medical School Hospital]

PURPOSE

To examine the factors which affect changes in the position of the eyes following the strabismus surgery.

METHODS

The postoperative position of 240 eyes with concomitant strabismus was examined. The factors which seemed to have an effect on the position of the eyes were enumerated, and a logistic regression analysis of the results was done.

RESULTS

In comparison with esotropia, in exotropia the eyes showed a tendency to return gradually to a normal position. There was no remarkable improvement in stereoscopic vision following strabismus surgery. Based on the standards of the Japanese Association of Strabismus and Amblyopia [the cure standard for strabismus], the results of strabismus surgery were as follows: Grade 1(cosmetically satisfactory) was mainly observed for esotropia, and Grade 3(good) for exotropia. The factors which had a significant effect on the postoperative position of the eyes were as follows: esotropia amblyopia, muscle movement, and operative methods; exotropia: retinal correspondence, operative methods, and the necessity of inferior oblique muscle surgery.

CONCLUSIONS

There was little correction of the position of the eyes. In individual cases, the factors which affect position of eyes were examined, and it was considered necessary to increase the amount of correction. Age is a factor which has an effect, but the effect on esotropia and exotropia is small.

Identification of protein kinase Calpha as an essential, but not sufficient, cytosolic factor for Ca2+-induced alpha- and dense-core granule secretion in platelets

Upon activation, platelets release many active substances. Here, we have analyzed the mechanism governing Ca(2+)-induced secretion of von Willebrand factor stored in alpha-granules and 5-hydroxytryptamine in dense-core granules in permeabilized human platelets. Both secretions were dependent on ATP and cytosol. An essential factor for both granule secretions was purified from rat brain cytosol and identified to be protein kinase Calpha (PKCalpha) by partial amino acid sequencing. Purified PKCalpha efficiently stimulated both secretions in the presence of cytosol, whereas PKCalpha alone did not support the secretion of either type of granules, suggesting that PKCalpha is not a sufficient factor. Finally, in human platelet cytosol fractionated by a gel filtration column, the stimulatory activity for dense-core granule secretion paralleled with the concentration of PKC, suggesting that PKC could also be such a stimulatory factor in platelet cytosol. Thus, we identified PKCalpha as an essential, but not sufficient, cytosolic factor for the Ca(2+)-induced secretions of both alpha- and dense-core granules in platelets.

Novel splice variants of PACAP gene in mouse cerebellar granule cells

The mouse pituitary adenylate cyclase activating polypeptide (PACAP) gene consists of two alternative exons (1A and 1B) and four exons including the coding region. By the usage of alternative exons, three transcripts can be produced. In this report, however, we found that at least five preproPACAP transcripts, including two novel types, were produced in mouse cerebellar granule cells (CGCs) and their expression was induced by the Ca2+ influx through L-type voltage-dependent Ca2+ channels. The splicing occurred between the 3'-donor site of exon 1A and the two novel internal 5'-acceptor sites of exon 1B. These findings suggest that preproPACAP transcripts are produced by the complicated usage of the 5'-untranslated region in an activity-dependent manner.

Small GTPase Rho regulates thrombin-induced platelet aggregation

Platelets play essential roles in hemostasis and thrombosis by aggregating with each other. However, the molecular mechanism governing platelet aggregation is not yet fully understood. Here, we established an assay system using platelets permeabilized with streptolysin-O to analyze mechanism of the thrombin-induced aggregation, focusing upon a controversial issue in the field whether small GTPase Rho regulates the aggregation. Incubation of the permeabilized platelets with Rho GDP-dissociation inhibitor, an inhibitory regulator for Rho family GTPases, extracted Rho family proteins extensively from the plasma and intracellular membranes, and inhibited the thrombin-induced aggregation. Incubation of the permeabilized platelets with botulinum exoenzyme C3, which specifically inhibits Rho function by ADP-ribosylating it, abolished the thrombin-induced aggregation. Thus, Rho is involved in thrombin-induced aggregation of platelets.

A new type of endo-xyloglucan transferase devoted to xyloglucan hydrolysis in the cell wall of azuki bean epicotyls

A new type of xyloglucan-degrading enzyme was isolated from the cell wall of azuki bean (Vigna angularis Ohwi et Ohashi cv. Takara) epicotyls and its characteristics were determined. The enzyme was purified to apparent homogeneity by Concanavalin A (Con A)-Sepharose, cation exchange, and gel filtration columns from a cell wall protein fraction extracted with 1 M sodium chloride. The purified enzyme gave a single protein band of 33 kDa on SDS-PAGE. The enzyme specifically cleaved xyloglucans and showed maximum activity at pH 5.0 when assayed by the iodine-staining method. An increase in reducing power in xyloglucan solution was clearly detected after treatment with the purified enzyme. Xyloglucans with molecular masses of 500 and 25 kDa were gradually hydrolyzed to 5 kDa for 96 h without production of any oligo- or monosaccharide with the purified enzyme. The purified enzyme did not show an endo-type transglycosylation reaction, even in the presence of xyloglucan oligosaccharides. Partial amino acid sequences of the enzyme shared an identity with endo-xyloglucan transferase (EXGT) family, especially with xyloglucan endotransglycosylase (XET) from nasturtium. These results suggest that the enzyme is a new member of EXGT devoted solely to xyloglucan hydrolysis.

Involvement of endogenous PACAP expression in the activity-dependent survival of mouse cerebellar granule cells

Membrane depolarization causes Ca2+ influx through L-type voltage-dependent calcium channels (L-VDCC), which promotes the activity-dependent survival of mouse cerebellar granule cells (CGCs). Although exogenously added pituitary adenylate cyclase activating polypeptide (PACAP) is effective in promoting the survival of CGCs, it is unknown whether PACAP is synthesized in CGCs and involved in the activity-dependent survival of CGCs. In this study, we found that the PACAP gene was activated in depolarized CGCs cultured at 25 mM KCl (high K+), independently of de novo protein synthesis. In addition, the PACAP immunoreactivity increased through the activation of L-VDCC in depolarized CGCs, indicating that PACAP is concomitantly produced with PACAP mRNA in an activity-dependent manner. Exogenously added PACAP attenuated the apoptosis of CGCs through a specific interaction with PACAP receptors. Furthermore, a PACAP receptor antagonist, PACAP(6-38), reduced the survival of CGCs at high K+. These findings indicate that endogenous PACAP production induced by Ca2+ signals exerts a survival effect on CGCs via PACAP receptors, which, at least in part, accounts for the activity-dependent survival of CGCs.

Repression of activity-dependent c-fos and brain-derived neurotrophic factor mRNA expression by pyrethroid insecticides accompanying a decrease in Ca(2+) influx into neurons

Permethrin, a type I pyrethroid insecticide, is known to affect sodium channels of neurons and prolong sodium currents. On the other hand, the expression of brain-derived neurotrophic factor (BDNF) and c-fos genes is activated through Ca(2+) influx into neurons, in an activity-dependent manner. In this study, therefore, we investigated whether permethrin influenced the Ca(2+) signal-induced expression of these genes. In primary culture of mouse cerebellar granule cells (CGCs), stimulation with veratridine, a potent agonist for sodium channels, which causes membrane depolarization in neurons, induced c-fos and BDNF mRNA expression accompanying the Ca(2+) influx into neurons. Pretreatment with permethrin at doses nontoxic to CGCs repressed the induction of these genes dose dependently, with trans-permethrin more potent than cis-permethrin. Consistent with this, the increase in Ca(2+) influx caused by veratridine was repressed by permethrin. The membrane depolarization induced by elevating the potassium (K(+)) concentration in medium (high K(+)) caused the activation of c-fos and BDNF genes, which was also repressed by permethrin. Immunoblotting analysis of c-Fos and a gel-mobility assay of AP-1 DNA-binding activity supported the decrease in c-Fos synthesis in permethrin-treated CGCs. The type II pyrethroid cypermethrin also affected the expression of these genes but less effectively than permethrin. Thus, pyrethroids inhibit the activity-dependent gene expression in neurons.

Small GTPase Rab4 regulates Ca2+-induced alpha-granule secretion in platelets

Upon activation, platelets release many active substances stored in alpha- and dense-core granules. However, the molecular mechanisms governing regulated exocytosis are not yet fully understood. Here, we have established an assay system using permeabilized platelets to analyze the Ca(2+)-induced exocytosis of both types of granules, focusing on RabGTPases. Incubation with Rab GDP dissociation inhibitor, an inhibitory regulator of RabGTPases, reduced membrane-bound RabGTPases extensively, and caused strong inhibition of the Ca(2+)-induced secretion of von Willebrand factor (vWF) stored in alpha-granules, but not that of [(3)H]5-hydroxytryptamine (5-HT) in dense-core granules. Specifically, Rab4 co-fractionated with vWF and P-selectin (an alpha-granule marker) upon separation of platelet organelles by density gradient centrifugation. Incubation of the permeabilized platelets with cell extracts expressing the dominant negative mutant of His-tagged Rab4S22N, but not with those of similar mutant His-Rab3BT36N, inhibited the vWF secretion, whereas neither of the cell extracts affected the [(3)H]5-HT secretion. Importantly, the inhibition of vWF secretion was rescued by depleting the cell extracts of the His-Rab4S22N with nickel beads. Thus, in platelets, the regulatory mechanisms governing alpha- and dense-core granule secretions are distinct, and Rab4 is an essential regulator of the Ca(2+)-induced exocytosis of alpha-granules.

Dynamic topography of pattern visual evoked potentials (PVEP) in psychogenic visual loss patients

We investigated to measure the objective visual acuity using pattern visual evoked potentials (PVEP) to help the diagnosis with psychogenic visual loss (PVL) who ranged in age from 7 to 14 years old. Pattern stimuli consisted of black and white checkerboard patterns (39, 26, 15 and 9') with a visual angle of 8 degrees and a contrast level of 15%. The pattern reversal frequency was 0.7 Hz. This resulted in an average of 100 PVEP per session. Visual acuity of 0.1 was consistent with the 39' pattern, 0.2 with the 26' pattern, 0.5 with the 15' pattern, and 1.0 with the 9' pattern. As the results, five PVL patients could measure visual acuity with this method in the present study. The PVEP is useful in evaluating the visual acuity and helped to diagnose the PVL patients. In addition we used the dynamic topography to study the difference in the results of the PVEP. The dynamic topography obtained from the results of the PVEP was analyzed. The flow type of the P100 component diverged into three types (separated type, hollow type and localized type) in the PVL patients and the normal children. The localized type was observed in 59.1% of normal children and in 56.3% of PVL patients. While the separated type was shown in 6.8% of normal children and in 8.3% of PVL patients. There were not significant differences between the PVL patients and the normal children in each type.

Differential activation of brain-derived neurotrophic factor gene promoters I and III by Ca2+ signals evoked via L-type voltage-dependent and N-methyl-D-aspartate receptor Ca2+ channels

Although the brain-derived neurotrophic factor (BDNF) gene is activated by the intracellular Ca(2+) signals evoked via Ca(2+) influx into neurons, little is known about how the activation of alternative BDNF gene promoters is controlled by the Ca(2+) signals evoked via N-methyl-d-aspartate receptors (NMDA-R) and L-type voltage-dependent Ca(2+) channels (L-VDCC). There is a critical range in the membrane depolarization caused by high K(+) concentrations (25-50 mm KCl) for effective BDNF mRNA expression and transcriptional activation of BDNF gene promoters I and III (BDNF-PI and -PIII, respectively) in rat cortical culture. The increase in BDNF mRNA expression induced at high K(+) was repressed not only by nicardipine, an antagonist for L-VDCC, but also by dl-amino-5-phosphonovalerate, an antagonist for NMDA-R, which was supported by the effects of antagonists on the Ca(2+) influx. Although the promoter activations at 25 and 50 mm KCl were different, BDNF-PIII was activated by either the Ca(2+) influx through NMDA-R or L-VDCC, whereas BDNF-PI was predominantly by the Ca(2+) influx through L-VDCC. Direct stimulation of NMDA-R supported the activation of BDNF-PIII but not that of BDNF-PI. Thus, the alternative BDNF gene promoters responded differently to the intracellular Ca(2+) signals evoked via NMDA-R and L-VDCC.

Growth regulation mechanisms in higher plants under microgravity conditions - changes in cell wall metabolism

During Space Shuttle STS-95 mission, we cultivated seedlings of rice (Oryza sativa L. cv. Koshihikari and cv. Tan-ginbozu) and Arabidopsis (Arabidopsis thaliana L. cv. Columbia and cv. etr1-1) for 68.5, 91.5, and 136 hr on board, and then analyzed changes in the nature of their cell walls, growth, and morphogenesis under microgravity conditions. In space, elongation growth of both rice coleoptiles and Arabidopsis hypocotyls was stimulated. Also, the increase in the cell wall extensibility, especially that in the irreversible extensibility, was observed for such materials. The analyses of the amounts, the structure, and the physicochemical properties of the cell wall constituents indicated that the decreases in levels and molecular masses of cell wall polysaccharides were induced under microgravity conditions, which appeared to contribute to the increase in the wall extensibility. The activity of certain wall enzymes responsible for the metabolic turnover of the wall polysaccharides was increased in space. By the space flight, we also confirmed the occurrence of automorphogenesis of both seedlings under microgravity conditions; rice coleoptiles showed an adaxial bending, whereas Arabidopsis hypocotyls elongated in random directions. Furthermore, it was shown that spontaneous curvatures of rice coleoptiles in space were brought about uneven modifications of cell wall properties between the convex and the concave sides.

Silencer-mediated repression and non-mediated activation of BDNF and c-fos gene promoters in primary glial or neuronal cells

Although the neuron-restrictive silencer element (NRSE/Regard) has been shown to function as a negative-acting DNA regulatory element to prevent the expression of neuron-specific genes in non-neuronal cells, little is known about its silencing effect on transcription in primary glial cells nor its effect on transcriptional activation in primary neurons. By DNA transfection in primary cultures of rat cortical neuronal or glial cells, we investigated the effect of NRSE on transcription mediated by the BDNF promoter I or c-fos promoter to which NRSE sequences derived from the SCG10 gene were linked. Transfection of plasmid DNAs to NIH3T3 fibroblasts resulted in a marked repressive effect of NRSE on BDNF promoter I- or c-fos promoter-mediated transcription. In primary neuronal cells, however, NRSE did not repress the basal promoter activities of BDNF and c-fos genes and allowed the transcriptional activation of these genes induced by membrane depolarization although NRSE slightly reduced the magnitude of BDNF promoter I activation. In contrast to neuronal cells, a marked repression of basal promoter activities of both genes was detected in primary glial culture and a two base pair-mutation of NRSE partially recovered the repression. These results indicate that NRSE negatively acts on its linked promoters in primary glial cells and does not interfere an activation of linked promoters in neuronal cells.

Baseline features of idiopathic optic neuritis as determined by a multicenter treatment trial in Japan. Optic Neuritis Treatment Trial Multicenter Cooperative Research Group (ONMRG)

BACKGROUND

An optic neuritis treatment trial was conducted at 30 clinical centers in Japan using the same protocol. Patient participation was based on: age range of 14-55 years; acute symptoms indicative of unilateral optic neuritis of unknown or demyelinating origin; visual symptoms of 14-day duration or less; relative afferent pupillary defect in affected eye; and normal or swollen optic disc of affected eye.

CASES

Initially, 102 patients qualified for participation; baseline data were obtained for analysis from 70 of these patients. Demographic characteristics of Japanese patients with optic neuritis were clarified and compared with those in a US study.

OBSERVATIONS

The incidence of ocular or periocular pain and the presence of periventricular plaques were noted to be lower, and the incidence of disc swelling higher, in the Japanese patients, suggesting racial differences in the characteristics of the disease. Such differences may possibly be related to the lower incidence of multiple sclerosis in Japanese patients. The results of visual function tests were virtually the same in both studies. The nonaffected eyes of more than half the patients showed abnormal mean deviation in Humphrey field analysis, as also noted in the US study.

CONCLUSIONS

The baseline clinical features of optic neuritis in the Japanese patients have been defined. Some racial differences in the characteristics of the disease may exist.

Multicenter clinical trial for evaluating methylprednisolone pulse treatment of idiopathic optic neuritis in Japan. Optic Neuritis Treatment Trial Multicenter Cooperative Research Group (ONMRG)

BACKGROUND

A randomized, controlled clinical trial was conducted in 1991 to compare an intravenous megadose of methylprednisolone with a control drug (mecobalamin) for treating acute idiopathic optic neuritis.

CASES

Sixty-six cases from 22 clinical centers throughout Japan were examined to evaluate the treatment on visual function parameters, such as visual acuity, visual field, color vision, contrast sensitivity, and critical flicker frequency.

OBSERVATIONS

The methylprednisolone pulse treatment group showed faster recovery of visual function, particularly the visual acuity at 1 week (P<.05), Humphrey field analyzer mean deviation at 3 weeks (P<.05), and color vision at 1 week (P<.05). Recovery of contrast sensitivity at several different spatial frequencies was significant in the pulse treatment group at 1 (P<.01), 2 (P<.05), and 4 weeks (P<.05) after the start of treatment. Visual function test results at 12 weeks and 1 year were essentially the same in the two treatment groups. Side effects appeared more frequently in the pulse treatment group than in the control (P<.05).

CONCLUSIONS

Pulse treatment does not appear effective for idiopathic optic neuritis even though visual function in the pulse treatment group of this trial recovered more quickly during the initial phase compared to the controls. More effective and specific treatment should be established for optic neuritis.

[Clinical results of supratentorial astrocytoma grade II]

At present, there is no consensus concerning the treatment of low-grade gliomas. The authors conducted a retrospective review of surgically treated, histologically verified cases of supratentorial astrocytomas of grade II to evaluate the results of current treatment methods. Thirty-seven patients, 23 males and 14 females, treated from April, 1977 through March, 1997 were analyzed. Median patient age was 36 years (range 2-69 years). All patients were diagnosed by surgical specimens. Thirty were fibrillary, and three were gemistocytic astrocytomas. There were 13 total resections, 7 subtotal resections, 10 partial resections. Of the remaining 7, diagnosis was obtained by stereotactic biopsy. Twenty patients were irradiated and two received chemotherapy. Follow-up information was obtained for 33 patients. The follow-up time ranged from 4 months to 246 months (mean, 9 years). Overall survival rates at 5 and 10 years for the entire treated group were 71% and 57% respectively. Total and subtotal resections were significantly associated with longer survival time, the 5- and 10-year survival rates were 93% and 67%, respectively. They were 40% and 40% in patients with partial resection or needle biopsy. Patients with gemistocytic astrocytoma had a poor prognosis with a median survival of 44.5 months. The influence of radiotherapy was not obvious: 92 and 69% of patients were alive at 5 and 10 years respectively without radiotherapy. The extent of surgery and histological type were by far the most important factors in predicting length of survival. The importance of an accurate histologic diagnosis and a gross total resection is emphasized.

Coactivation of secretogranin-II and BDNF genes mediated by calcium signals in mouse cerebellar granule cells

In primary culture of mouse cerebellar granule cells, the brain-derived neurotrophic factor (BDNF) gene is activated in an activity-dependent manner, accompanying Ca2+ influx into neurons through voltage-dependent calcium channels (VDCCs). In this study, we investigated the inducibility of secretogranin-II (Sg-II) gene in terms of Ca2+ signals evoked via VDCCs, by a comparison with BDNF and c-fos genes. Deprivation and subsequent induction of membrane depolarization by lowering and reelevating the extracellular concentration of potassium chloride (KCl), respectively, led to an decrease and then an increase in the Sg-II, BDNF and c-fos mRNA expression. The increase in Sg-II mRNA expression was detected as early as but was slower than that of BDNF one. The increase in Sg-II mRNA expression was induced depending upon the extracellular Ca2+ and inhibited by nicardipine, indicating a requirement of Ca2+ influx through VDCCs for the Sg-II as well as BDNF gene induction. Inhibition of de novo protein synthesis by cycloheximide did not affect the Sg-II induction. The response of Sg-II gene to the changes in extracellular KCl concentration was the same as that of BDNF but different from that of c-fos gene. Thus, Sg-II gene is coactivated with BDNF gene in response to the intracellular Ca2+ signals evoked via Ca2+ influx through VDCCs.

Primary brain tumors in children under age 3 years

During the period from 1966 to 1996 the authors analyzed the clinicopathological characteristics of 46 cases of histologically verified primary brain tumors with symptomatic onset during the first 3 years of life. The patient group included 27 males and 19 females. There were 14 patients during the first year, 13 during the second year, and 19 during the third year. Supratentorial tumors (60.9%) were more common than infratentorial tumors. Histologically, neuroepithelial tumors predominated. The incidence of ependymal tumors, particularly malignant ones, and of neuronal/mixed neuronal-glial tumors was higher than in previous reports. Congenital brain tumors, those occurring within 2 months after birth, or tumors of dysplastic origin comprised 42.9% of the tumors that developed within 1 year of birth. At the onset, macrocephaly, failure to thrive, and seizures were prominent symptoms or signs in the younger patients. Focal neurological deficits and increased intracranial pressure predominated in the older patients. All but one patient underwent surgical treatment, and 17 patients received adjuvant therapy after surgery. The prognosis was mainly related to the histology of the malignancy. The outcome of medulloblastomas was poor. The quality of life of surviving patients was relatively good, 77.8% having better performance status (PS) than the Eastern Cooperative Oncology Group PS 2.

Inducibility of BDNF gene promoter I detected by calcium-phosphate-mediated DNA transfection is confined to neuronal but not to glial cells

Although DNA transfection with calcium-phosphate/DNA precipitates for promoter analysis of genes has been previously applied to primary cultures of neuronal cells, it remains uncertain whether the expression of the introduced genes in glial cells, which are also in primary culture, affects the transcriptional signals obtained. Using plasmid DNA containing the brain-derived neurotrophic factor (BDNF) gene promoter I or c-fos promoter, we investigated the optimum conditions for calcium-phosphate-mediated DNA transfection in primary culture of rat cortical neuronal cells. Normalizing the firefly luciferase activity of the experimental reporter gene to the Renilla luciferase activity of the internal control increased experimental reliability. Maximum expression of firefly luciferase activity in the cells stimulated by membrane depolarization required 6-12 hrs of incubation after stimulation. Differences in the ratio of the experimental reporter gene to the internal control did not affect experimental gene expression. Under our optimal conditions, the activation of the BDNF gene promoter I was detected in neuronal but not in glial cells. Calcium-phosphate-mediated DNA transfection should be widely applicable for promoter analysis of inducible genes in neurons.

Primary intracranial germinoma involving the midbrain

To our knowledge, this is the first reported case of a germinoma involving the midbrain without the demonstrable coexistence of any common midline tumors. A 27-year-old man was referred to our institution for evaluation and treatment of diplopia persisting for 5 years. Magnetic resonance imaging (MRI) showed the mass in the midbrain to be of iso intensity on T1-weighted images, and of high intensity on T2-weighted images with homogeneous enhancement. MRI-guided stereotactic biopsy was performed, and the histologic diagnosis was germinoma. Following biopsy, external beam radiotherapy of 50 Gy (whole brain 30 Gy: local 20 Gy) was performed. At the time of discharge, the patient's neurological symptoms had resolved. Follow-up MRI revealed disappearance of the tumor. These findings suggest the diagnostic value of magnetic resonance image-guided stereotactic biopsy in the differential diagnosis of adult brainstem lesions, which should now include germinoma.

Left ventricular mass regression after implantation of St. Jude Medical cardiac valves in small aortic roots

In this study, we analyzed the extent of regression of left ventricular hypertrophy in patients who received small St. Jude Medical (SJM) aortic valves and compared the results with those of another group receiving larger valves. Eighty-eight patients received either 19 or 21 mm valves (Group 1, 25 patients) or either 23 or 25 mm valves (Group 2, 53 patients). Echocardiographic studies were done before the operation and 5 years postoperatively. At follow-up a significant reduction in the left ventricular mass was found for both patient groups (p < 0.0001). Doppler echocardiography derived pressure gradients for both groups were obtained during the follow-up period. As expected, the patients in Group 1 had higher peak pressure gradients than did those in Group 2. However, there was no significant difference between the 2 groups or any significant correlations between peak pressure gradients and body surface area (BSA). Actuarial survival was 84.7% at 15 years for Group 1 and 85.9% at 17 years for Group 2. Actuarial freedom from valve related events was 91.4% at 15 years for Group 1 and 82.7% at 17 years for Group 2. There was no significant difference in survival or valve related event free curves between the 2 groups. After implantations of SJM valves in small aortic roots, significant left ventricular mass regression was obtained, and the results were comparable to those for valves of other sizes. The long-term performance of aortic valve replacement with small valves was satisfactory as judged by improvement in the functional class of patients and survival statistics, the durability of the prosthesis, and valve related morbidity comparable to that of valves of other sizes.

[Long-term follow-up of patients with small St. Jude aortic valve prostheses]

Thirty-five patients received small sized 19 or 21 mm valves (group I) and 53 patients received 23 or 25 mm valves (group II). At follow-up a significant reduction in the left ventricular mass was found for both patient groups (p < 0.0001). The patients in group I had higher peak pressure gradients than did those in group II. However, there was no significant difference between the two groups, or any significant correlation between peak pressure gradients and body surface area. Actuarial survival was 84.7% at 15 years for group I and 85.9% at 17 years for group II. Actuarial freedom from valve-related events was 91.4% at 15 years for group I and 82.7% at 17 years for group II. There was no significant difference in survival or valve-related event free curves between the two groups. After implantation of small SIM valves, significant left ventricular mass regression was obtained and the results were comparable to those for valves of other sizes. The long-term performance of aortic valve replacement with small valves was satisfactory as judged by improvement in the functional class of patients, survival statistics, the durability of the prosthesis, and valve related morbidity comparable to that of valves of other sizes.

Attenuation of cell death mediated by membrane depolarization different from that by exogenous BDNF in cultured mouse cerebellar granule cells

Membrane depolarization accompanying calcium (Ca2+) influx into neurons is thought to play an essential role in controlling the survival and death of cultured mouse cerebellar granule cells (CGCs). In this study, we sequentially controlled the survival and death of CGCs in culture and monitored the expression of several kinds of genes including brain-derived neurotrophic factor (BDNF) gene. Deprivation and subsequent induction of membrane depolarization by lowering and re-elevating the extracellular concentration of potassium chloride, respectively, led to death of CGCs and then to an attenuation of the death process depending upon the Ca2+ influx into CGCs through voltage-dependent calcium channels (VDCCs). De novo protein synthesis was critical for attenuating the death of non-depolarized CGCs. Accompanying this attenuation was an activation of c-fos and BDNF genes and an inactivation of c-jun and neurotrophin-3 (NT-3) genes. The attenuation of cell death mediated by exogenous BDNF was only partial compared to that by membrane depolarization, suggesting that not only BDNF but also other factors could be involved in the membrane depolarization-mediated attenuation of death of CGCs. In good agreement with this observation, the mode of activation of c-fos, c-jun, BDNF and NT-3 genes induced by exogenous BDNF was different from that induced by membrane depolarization. Thus, membrane depolarization effectively attenuates the death of non-depolarized CGCs, the mode of which seems to be different from that mediated by BDNF alone.

[A case of ruptured descending thoracic aortic aneurysm due to Salmonella infection]

A 66-year-old male was admitted to our hospital because of pyrexia, chest pain and hemosptum. Inflammatory findings were made and salmonella enteritidis was detected by bacterial examination of sputum and stool. Enhanced chest CT examination disclosed a descending thoracic aortic aneurysm which had ruptured into the left lower lobe of the lung. Under a diagnosis of ruptured mycotic descending thoracic aortic aneurysm, an emergency operation was performed. A left posterolateral thoracotomy carried out after axillo-bilateral femoral bypass grafting. A pseudoaneurysm of the descending thoracic aorta had ruptured into the left lower lobe of the lung. After resection of the aneurysm, closure of both ends of the intact descending thoracic aorta and a left lower lobectomy were carried out. An ascending aorta-infrarenal abdominal aorta bypass was performed because of insufficient visceral arterial blood flow through the axillo-bilateral femoral bypass. The patient's immediate postoperative recovery was complicated by paraplegia. Chloramphenicol and levofloxacin were administered for three months, after which his recovery followed a good course.

Interaction of P1 RepA with replication origin of plasmid Rts1: capability of an initiator protein inducing replication from a foreign origin

Rts1 RepA and P1 RepA are trans-acting proteins essential for the initiation of replication of plasmid Rts1 and prophage P1, respectively. In this study, we found that, in vitro, P1 RepA bound to the Rts1 ori fragment and Rts1 incI fragment as strongly as Rts1 RepA. In addition P1 RepA, in trans, activated the Rts1 replication origin that was cloned in pBR322, thus allowing the ori plasmid to be maintained in a polA E. coli host. Under these conditions, however, the ori plasmid was unstable as compared with that when activated by Rts1 RepA. In addition, we found that Rts1 RepA showed no interaction with the P1 replication origin.

The diagnosis and management of splanchnic artery aneurysms. Report of 8 cases

The purpose of this report is to describe the clinical characteristics and surgical technique for splanchnic artery aneurysms. Over the past 10 years we have surgically resected 8 cases of splanchnic artery aneurysms including 2 cases involving the superior mesenteric artery, 3 involving the renal artery, 1 involving the hepatic artery and 2 involving the splenic artery. Diagnosis was established preoperatively in all patients by splanchnic angiography. Surgical treatment for splanchnic artery aneurysms is indicated in any symptomatic patient, in all symptomatic patients with suspected renal aneurysmal expansion and in patients who have renal aneurysms occurring with functionally important renal stenosis, usually associated with hypertension, in all patients with surgical accessible hepatic artery aneurysms, in all patients who have superior mesenteric artery aneurysms having a high tendency to rupture, and in all patients with an asymptomatic splenic artery aneurysms 1.5 cm or larger in diameter. Although splanchnic artery aneurysms are uncommon and asymptomatic, we recommend that splanchnic arteries should be treated surgically because of their tendency to rupture or organ failure.

[Brain damage after surgery for thoracic aortic aneurysm]

We analyzed cases with brain damage after surgery for thoracic aortic aneurysm in our institution and investigated the causes, risk-factors and preventive measures for this disastrous postoperative complication. Irreversible brain damage was a complication in 25 out of 184 operative cases (13.6%) over a 21-year period. The cause of brain damage was determined to be embolism by manipulation of the aorta in six cases, clamping of the left subclavian artery in four cases, technical problems of separate cerebral perfusion (SCP) in four cases, severe shock in three cases, embolism unrelated to operative maneuver in three cases, stenosis of a branch of the arch with aortic dissection in two cases, and air embolism, circulatory arrest with insufficient hypothermia and hypoperfusion of a temporary bypass to the left carotid artery in one case each. The neurological symptom improved in eight cases and was unchanged in 17 cases. Eighteen cases died in the hospital. In the univariate analysis, age (p = 0.048), a portion of the aneurysm (p = 0.035), preoperative brain complication (p = 0.003), emergency operation (p = 0.033) and clamping of the arch (p = 0.001) were found to be prominent risk factors for brain damage. In the multivariate analysis, clamping of the arch (p = 0.0310), SCP (p = 0.0327) and emergency operation (p = 0.0223) were prominent. To prevent postoperative brain damage, the arch should not be clamped, appropriate operative techniques to avoid bleeding and to shorten SCP time should be employed, and proper and prompt management of the emergency operation and caution in clamping the left subclavian artery are considered to be necessary.

[Visual acuity measured by pattern visual evoked potential]

We investigated the appropriateness of a method for the assessment of visual acuity using pattern visual evoked potentials (PVEP) in which retinal X-ganglion cells are predominantly stimulated. Eighteen normal eyes (average 22.2 years old) with normal acuity of 1.0 were examined. The stimulus consisted of white and black checkerboards (39', 26', 15' and 9') with a visual angle of eight degrees and a contrast level of 15%. The pattern reversal frequency was 0.7 Hz. This resulted in 100 averaged PVEP per session. We judged visual acuity from responses of the P100 component. Visual acuity was judged to be 0.1, so that there was response to the 39' checkerboard stimulus pattern, but not to the 26' pattern. Consequently, the accuracy for visual acuity was 76.9% for 0.1, 71.4% for 0.2, 70.0% for 0.5 and 58.3% for 1.0. This method, which uses a stimulus pattern with a small visual angle, low contrast, and low pattern reversal frequency, is useful for subjective measurement of the visual acuity of infants or handicapped children whom it is difficult to measure by the conventional objective method of measuring visual acuity with Landolt's rings.

Synthesis of glycosyl-trehaloses by cyclomaltodextrin glucanotransferase through the transglycosylation reaction

Cyclomaltodextrin glucanotransferase from Bacillus stearothermophilus produced a series of glycosyl-trehaloses through the transglycosylation reaction with cyclomaltohexaose as the glycosyl donor and trehalose as its acceptor. After beta-amylase treatment, five species of glycosyl-trehaloses were isolated by column chromatography. After chemical and enzymatic analyses, it was concluded that these oligosaccharides were alpha-maltosyl alpha-D-glucopyranoside, alpha-maltotriosyl alpha-D-glucopyranoside, alpha-maltosyl alpha-maltoside, alpha-maltotriosyl alpha-maltoside, and alpha-maltotriosyl alpha-maltotrioside. These were not hydrolyzed by salivary amylase, artificial gastric juice, or pancreatic amylase, however they were hydrolyzed by enzymes of the small intestine.

[Ruptured descending thoracic aortic aneurysm due to aortitis syndrome--a case report]

Ruptured fusiform descending thoracic aortic aneurysms due to aortitis syndrome are rare. A 29-year-old woman was readmitted to our hospital with a chief complaint of back pain and shock, and diagnosed as having rupture of a descending thoracic aortic aneurysm. She had a past history of aortitis syndrome beginning eight years ago. On chest CT examination earlier a year, the descending thoracic aortic aneurysm was 4.5 cm in diameter, and calcification we observed in the aortic wall. An inflammatory reaction had been controlled by steroid therapy and her blood pressure had been controlled by vasodilator drugs. Emergent graft replacement of a descending aortic aneurysm was successfully performed under a femoro-femoral bypass using a centrifugal pump and membrane oxygenerator, and Cell Sver. Although in the literature surgical treatment is indicated only if there is a symptomatic or enlarging aneurysm especially of saccular type and no operation is justified for an aortic aneurysm showing marked calcification, we concluded that aggressive surgical treatment was necessary for this fusiform aneurysm due to aortitis syndrome.

[Recurrent intrathoracic dissemination of thymoma with myasthenia gravis: a case report]

A 48-year-old man was readmitted to our hospital with a chief complaint of left anterior chest mass. He had a past history of thymo-thymomectomy six years earlier. On chest CT examination, multiple tumor shadows were noted within the left thoracic cavity. All visible tumors were resected. His postoperative course was favorable, and no signs of recurrence have been recognized on CT to date (three years and six months postoperatively). However, in view of the possible recurrence of the present disease after a long period, strict observation of the course of the disease is necessary.

[A case report of malignant schwannoma of the chest wall]

We described a very rare case of malignant schwannoma of the chest wall, which was surgically resected. The patient, a 40-year-old woman, came to our hospital because of an abnormal shadow in the right chest wall of an X-ray film without any symptoms. Computed tomography revealed a solid tumor attached to the posteroinferior aspect of the intrathoracic chest wall. The tumor was a 2.5 x 2.1 cm, mass originating from the seventh intercostal nerve without pulmonary adhesion, and the patient underwent en bloc resection of the tumor. The pathological diagnosis was malignant schwannoma. The postoperative course was uneventful, and the patient, eight years after the operation is now doing well without local recurrence or distant metastasis. We reviewed seven cases of this type of tumor reported in the Japanese literature.

BDNF gene can Be activated by Ca2+ signals without involvement of de novo AP-1 synthesis

Although stimulation of N-methyl-D-aspartate receptors or voltage-dependent calcium channels induces both the activation of c-fos and brain-derived neurotrophic factor (BDNF) genes, it is not certain how the activation of these genes is related. Using primary cultures of rat hippocampal neurons, we found that exposing the cells to cycloheximide allowed subsequent activation of BDNF mRNA expression, although activation of AP-1 DNA-binding activity resulting from the c-fos induction was abolished. Super-induction of BDNF gene was also caused by cycloheximide. The estimated half-life of BDNF mRNA was approximately 2.5 hrs, which was almost identical to that of c-fos mRNA. These results indicate that nascent AP-1 is not required for the activation of BDNF gene, leading to the notion that the BDNF gene can be activated by Ca2+ signals as an immediate early gene.