Induction of Immunological Antitumor Effects by the Combination of Adenovirus-Mediated Gene Transfer of B7-1 and Anti-Programmed Cell Death-1 Antibody in a Murine Squamous Cell Carcinoma Model

BACKGROUND

The goal of this study was to evaluate the antitumor immune effects of B7-1 gene expression in addition to immune checkpoint inhibitor against squamous cell carcinoma.

METHODS

A murine SCC cell line, KLN205, was infected with adenoviral vector carrying B7-1 (AdB7). Infected cells were injected subcutaneously in the flanks of DBA/2 mice. Three weeks after implantation, anti-mouse PD-1 antibody (antiPD1) was intraperitonially administrated twice a week for a total of six times.

RESULTS

CD80 was significantly overexpressed in the AdB7-infected tumors. IFN-gamma in the T cells in the spleen was significantly increased and tumor size was significantly reduced in the mice treated with both AdB7 and antiPD1. Targeted tumors treated with both AdB7 and antiPD1 exhibited significantly increased cell densities of total immune cells as well as Ki-67+ CD8+ T cells and decreased regulatory T cells.

CONCLUSIONS

These results suggest that the B7-1 gene transfer may enhance the antitumor effect of anti-PD1 antibody against SCC.

Vestibular function after simultaneous bilateral cochlear implantation in adults

Introduction

Binaural hearing enhances speech intelligibility, source localization, and speech comprehension in noisy environments. Although bilateral cochlear implantation (CI) offers several benefits, concerns arise regarding the risk of bilateral postoperative vestibular dysfunction with simultaneous CI. This study aimed to longitudinally evaluate changes in vestibular function in adult patients who underwent simultaneous bilateral CI using minimally invasive electrodes and surgical techniques.

Methods

A retrospective review was conducted on 10 patients who underwent simultaneous bilateral CI at our hospital. Vertigo symptoms and vestibular function test results were examined preoperatively, 1-6 months postoperatively, and 1 year postoperatively. Nystagmus tests, caloric reflex tests, vestibular evoked myogenic potentials (VEMP) measurements, and static stabilometry were performed as vestibular function tests.

Results

Although an initial transient decline in vestibular function was observed, no significant long-term decline was observed in the caloric reflex test, ocular VEMP (oVEMP), or cervical VEMP (cVEMP). Moreover, regardless of the presence or absence of abnormalities in caloric reflex, oVEMP, or cVEMP, no significant deterioration was detected in the static stabilometer test. While two patients reported preoperative dizziness, all patients were symptom-free 1 year postoperatively.

Discussion

The findings suggest that using current minimally invasive electrodes and surgical techniques in simultaneous bilateral CI leads to temporary vestibular function decline postoperatively. However, most patients experience a recovery in function over time, highlighting the potential safety and efficacy of the procedure. Simultaneous bilateral CI surgery is viable, depending on the patient's auditory needs and burden.

Oncological outcomes of concurrent chemoradiotherapy with docetaxel, cisplatin, and 5-fluorouracil for locally advanced squamous cell carcinoma of the external auditory canal: A single-center study

BACKGROUND

Squamous cell carcinoma of the external auditory canal (EACSCC) is a rare condition. However, a standard treatment has not yet been established. We retrospectively evaluated the efficacy, adverse events, and feasibility of TPF-CCRT (concomitant chemoradiotherapy with docetaxel, cisplatin, and 5-fluorouracil) in patients with advanced EACSCC.

METHODS

Thirty-five consecutive patients with advanced EACSCC (T3, T4) initially treated with TPF-CCRT at Kobe University Hospital were included. T4 diseases with invasion of the brain, internal carotid artery, or internal jugular vein were classified as T4b, and those without these features were classified as T4a.

RESULTS

Five-year overall survival rates for T3 and T4 were 100% and 64.2%, respectively. A significant difference was observed between T4a and T4b (82.4% vs. 30%, p = 0.007). Five-year progression-free survival rates of T3, T4a, and T4b were 100%, 68%, and 20% (p = 0.022), respectively.

CONCLUSIONS

TPF-CCRT should be considered as a plausible treatment option for advanced EACSCC.

Live Imaging of the Dehydration Effect of Isosorbide on the Normal and Hydropic Guinea Pig Cochleae Using Optical Coherence Tomography

OBJECTIVE

To investigate the isosorbide-induced dehydration effect on the endolymphatic space by intratympanic administration of isosorbide.

BACKGROUND

Isosorbide, an osmotic diuretic, is used orally as a typical conservative therapy for Menière's disease (MD) in Japan. The dehydration effect occurs 6 hours after isosorbide ingestion. Intratympanic administration of isosorbide resolves endolymphatic hydrops faster than oral ingestion. In addition, the dehydration effect has never been shown directly. Therefore, we investigated the dehydration effect of intratympanic administration of isosorbide on endolymphatic hydrops using optical coherence tomography.

METHODS

We used eight Hartley guinea pigs, divided into normal and hydrops groups. In the hydrops group, the animals underwent endolymphatic sac obliteration to create endolymphatic hydrops. We obtained midmodiolar section images of the cochleae using optical coherence tomography. Then, 50 to 70% isosorbide was sequentially administered intratympanically for 5 minutes, and the apical turn of the cochlea was observed. The relative midmodiolar cross-sectional area of the scala media was calculated for quantitative assessment of the endolymphatic space.

RESULTS

In the normal group, 50% isosorbide had a slight but significant dehydration effect on the scala media; at 55 to 70%, Reissner's membrane became flat. In the hydrops group, 50% isosorbide slightly reduced endolymphatic hydrops; 65% flattened Reissner's membrane, and 70% slightly concaved it toward the basilar membrane.

CONCLUSION

The results suggest that we could select the concentration of isosorbide according to the stage or severity of MD and relief from acute attack. Intratympanic administration of isosorbide may be a promising treatment for patients with MD.

Factors that affect the development of acute hemorrhagic rectal ulcer syndrome and rebleeding

Objectives

Acute hemorrhagic rectal ulcer syndrome (AHRUS) causes massive bleeding and often recurrent rebleeding from rectal ulcers that form immediately above the dentate line. This study aimed to determine the clinical background and risk factors contributing to rebleeding in patients with AHRUS and the most appropriate method of hemostasis treatment.

Methods

This retrospective study included 93 patients diagnosed with AHRUS at Showa University Fujigaoka Hospital, Japan, between April 2009 and November 2018. Information on clinical background factors, endoscopic findings, and hemostasis was obtained from medical records. The relationship with episodes of rebleeding was analyzed by multivariate logistic regression analysis.

Results

The median age was 79 years, and 84 patients (90%) had a performance status of grade 2 or higher. The patients had multiple background factors, with a median number of 5 per patient. The background factors could be classified into two major factors: those related to arteriosclerosis and those related to delayed wound healing.

In the multivariate analysis, significantly more rebleeding occurred in patients with active bleeding during the initial endoscopy (odds ratio 4.88, 95% confidence interval 1.80–14.46, p = 0.003); significantly less rebleeding occurred in patients for whom hemostasis was first performed by clipping (odds ratio 0.30, 95% confidence interval 0.09–0.88, p = 0.035).

Conclusions

In bedridden older individuals with poor general health, multiple combinations of arteriosclerosis‐related factors and protracted wound healing factors can induce AHRUS. We strongly recommend performing hemostasis via the clipping method on suspected bleeding points, including active bleeding sites, in AHRUS.

Genetic variants of cancer‑associated genes analyzed using next‑generation sequencing in small sporadic vestibular schwannomas

Vestibular schwannoma (VS) is the most common tumor of the cerebellopontine angle. Despite the increasing diagnosis of sporadic VS over the past decade, the use of traditional microsurgeries to treat VS has decreased. This is likely a result of the adoption of serial imaging as the most common initial evaluation and treatment strategy, especially for small-sized VS. However, the pathobiology of VSs remains unclear, and elucidating the genetic information of tumor tissue may reveal novel insights. The present study performed a comprehensive genomic analysis of all exons in the key tumor suppressor and oncogenes from 10 small (<15 mm) sporadic VS samples. The evaluations identified NF2, SYNE1, IRS2, APC, CIC, SDHC, BRAF, NUMA1, EXT2, HRAS, BCL11B, MAGI1, RNF123, NLRP1, ASXL1, ADAMTS20, TAF1L, XPC, DDB2 and ETS1 as mutated genes. The current study could not draw any new conclusions about the relationship between VS-related hearing loss and gene mutations; however, it did reveal that NF2 was the most frequently mutated gene in small sporadic VS.

Case report: Late middle-aged features of FAM111A variant, Kenny-Caffey syndrome type 2-suggestive symptoms during a long follow-up

Kenny-Caffey syndrome type 2 (KCS2) is an extremely rare skeletal disorder involving hypoparathyroidism and short stature. It has an autosomal dominant pattern of inheritance and is caused by variants in the FAM111 trypsin-like peptidase A (FAM111A) gene. This disease is often difficult to diagnose due to a wide range of more common diseases manifesting hypoparathyroidism and short stature. Herein, we present the case of a 56-year-old female patient with idiopathic hypoparathyroidism and a short stature. The patient was treated for these conditions during childhood. Upon re-evaluating the etiology of KCS2, we suspected that the patient had the disorder because of clinical manifestations, such as cortical thickening and medullary stenosis of the bones, and lack of intellectual abnormalities. Genetic testing identified a heterozygous missense variant in the FAM111A gene (p.R569H). Interestingly, the patient also had bilateral sensorineural hearing loss and vestibular dysfunction, which have been rarely described in previous reports of pediatric cases. In KCS2, inner ear dysfunction due to Eustachian tube dysfunction may progress in middle age or later. However, this disease is now being reported in younger patients. Nevertheless, our case may be instructive of how such cases emerge chronically after middle age. Herein, we also provide a literature review of KCS2.

A case of myeloperoxidase-antineutrophil cytoplasmic antibody and anticardiolipin antibody-positive pyogenic arthritis, pyoderma gangrenosum, acne and hidradenitis suppurativa (PAPASH) syndrome with colitis

A previous case report of colitis and serine proteinase 3-antineutrophil cytoplasmic antibody positivity in pyogenic arthritis, pyoderma gangrenosum (PG), acne and hidradenitis suppurativa (PAPASH) syndrome with colitis has been published. Herein, we report a similar case of myeloperoxidase-antineutrophil cytoplasmic antibody (MPO-ANCA) positivity. A 26-year-old man presented with recurrent aseptic pyogenic arthritis, acne, hidradenitis suppurativa and PG. Lower gastrointestinal endoscopy was performed, and colitis was observed. No PSTPIP1 gene mutation was found in the gene-sequencing test. Based on these findings and prior case reports, we diagnosed the patient with PAPASH syndrome, a PAPA spectrum disorder complicated by colitis. This patient had PAPASH syndrome with colitis and was MPO-ANCA and anticardiolipin antibodies-positive; it is unclear whether these antibodies play a role in this disease, but it may provide clues to further elucidate its pathogenesis.

Reconstruction of the external auditory canal using full-thickness rolled-up skin graft after lateral temporal bone resection for T1 and T2 external auditory canal cancer

OBJECTIVE

To present our results of the external auditory canal (EAC) reconstruction procedure using rolled-up full-thickness skin graft with tympanoplasty after lateral temporal bone resection (LTBR) for early-stage EAC carcinoma.

PATIENTS AND METHODS

A retrospective review of 15 patients who had undergone LTBR with reconstruction of the EAC for T1 and T2 EAC cancer between 2016 and 2020.

RESULTS

Postoperative mean air-bone gap was 30.7 decibel hearing level. Although a few patients experienced chronic granulation, persistent otorrhea, and/or laterization of the tympanic membrane, most patients showed no serious complications related to the EAC reconstruction.

CONCLUSION

EAC reconstruction using a full-thickness skin graft in combination with tympanoplasty is useful for minimizing the hearing loss, maintaining the cosmetic appearance, and facilitating the observation into the ear cavity.

Live imaging and functional changes of the inner ear in an animal model of Meniere's disease

The symptoms of Meniere's disease (MD) are generally considered to be related to endolymphatic hydrops (EH). There are many recent reports supporting the possibility that vasopressin (VP) is closely linked to the formation of EH in Meniere's disease. Based on this, we developed a clinically relevant animal model of Meniere's disease in which a VP type 2 receptor agonist was administered after electrocauterization of the endolymphatic sac. We report live imaging of the internal structure, and functional changes of the inner ear after electrocauterization of the endolymphatic sac and administration of a VP type 2 receptor agonist. In this model, the development of EH was visualized in vivo using optical coherence tomography, there was no rupture of Reissner's membrane, and low-tone hearing loss and vertiginous attacks were observed. This study suggested that acute attacks are caused by the abrupt development of EH. This is the first report of live imaging of the development of EH induced by the administration of a VP type 2 receptor agonist.

Oncolytic effect of Midkine promoter-based conditionally replicating adenoviruses expressing EGFR siRNA in head and neck squamous cancer cell line T891

Background

Epidermal growth factor receptor (EGFR) is overexpressed in head and neck squamous cell carcinomas (HNSCCs). Midkine expression is restricted in adult tissues but is increased in several malignant tumors, including HNSCCs.

Aim

Here, we evaluated the antitumor effect of Midkine promoter–based conditionally replicative adenovirus expressing siRNA against EGFR for targeting HNSCCs expressing Midkine.

Methods and results

A conditionally replicative adenovirus vector controlled by the Midkine promoter, Ad‐MK‐siEGFR, was generated by integrating gene‐expressing siRNA against EGFR. Antitumor effect of Ad‐MK‐siEGFR was tested in vitro using established HNSCC cell line, T891 with strong Midkine expression. Expression of EGFR in T891 infected with Ad‐MK‐siEGFR was significantly lower than that of T891 infected with control. Cytotoxicity assays showed significant growth suppression of Ad‐MK‐siEGFR in T891 cells.

Conclusions

This study demonstrated the possibility of oncolytic therapy using the Midkine promoter–based conditional replication‐selective adenovirus containing siRNA against EGFR in HNSCC cell line T891. Further validation of the findings in more cell lines and in vivo should be performed to clarify the potential clinical application.

Efficacy and suitable indication of colorectal endoscopic submucosal dissection using a balloon-assisted endoscope

Background and Aim

Cases of colorectal endoscopic submucosal dissection (ESD) with poor maneuverability are often encountered. We aimed to evaluate the efficacy of balloon‐assisted endoscopy (BAE) for such cases.

Methods

We confirmed maneuverability preoperatively in 400 consecutive cases of colorectal ESD performed at a single center from April 2011 to April 2018. A total of 83 deep colon cases judged as having poor maneuverability were retrospectively reviewed; 54 cases underwent BAE with a single balloon endoscope (group B), and 29 cases underwent conventional procedures without BAE (group C). Tumor size, procedure duration, dissection speed, en bloc resection rate, histology, and associated complications were compared between groups.

Results

The mean tumor size, tumor invasiveness, fibrosis, and complications did not differ between groups. Although the en bloc resection rate did not differ (both 98%), the groups significantly differed with regard to the R0 resection rate (B: 96%; C: 83%; P = 0.048). Overall, the procedure duration (B: 51 min; C: 70 min; P = 0.17) and dissection speed (B: 19.4 mm²/min; C: 17.4 mm²/min; P = 0.13) were not significantly different between groups. However, the dissection speed for lesions in the cecum/ascending colon was significantly faster in group B than in group C (B: 22.3 mm²/min; C: 11.3 mm²/min; P = 0.037).

Conclusions

In cases of colorectal ESD with poor maneuverability, the use of BAE contributed to an improvement in the R0 resection rate. In addition, BAE contributed to a quicker dissection speed for lesions located in the cecum/ascending colon.

Clinical Characteristics and In Vitro Analysis of MYO6 Variants Causing Late-Onset Progressive Hearing Loss

MYO6 is known as a genetic cause of autosomal dominant and autosomal recessive inherited hearing loss. In this study, to clarify the frequency and clinical characteristics of hearing loss caused by MYO6 gene mutations, a large-scale genetic analysis of Japanese patients with hearing loss was performed. By means of massively parallel DNA sequencing (MPS) using next-generation sequencing for 8074 Japanese families, we found 27 MYO6 variants in 33 families, 22 of which are novel. In total, 2.40% of autosomal dominant sensorineural hearing loss (ADSNHL) in families in this study (32 out of 1336) was found to be caused by MYO6 mutations. The present study clarified that most cases showed juvenile-onset progressive hearing loss and their hearing deteriorated markedly after 40 years of age. The estimated hearing deterioration was found to be 0.57 dB per year; when restricted to change after 40 years of age, the deterioration speed was accelerated to 1.07 dB per year. To obtain supportive evidence for pathogenicity, variants identified in the patients were introduced to MYO6 cDNA by site-directed mutagenesis and overexpressed in epithelial cells. They were then assessed for their effects on espin1-induced microvilli formation. Cells with wildtype myosin 6 and espin1 co-expressed created long microvilli, while co-expression with mutant constructs resulted in severely shortened microvilli. In conclusion, the present data clearly showed that MYO6 is one of the genes to keep in mind with regard to ADSNHL, and the molecular characteristics of the identified gene variants suggest that a possible pathology seems to result from malformed stereocilia of the cochlear hair cells.

Prevalence and clinical features of hearing loss caused by EYA4 variants

Variants in the EYA4 gene are known to lead to autosomal dominant non-syndromic hereditary hearing loss, DFNA10. To date, 30 variants have been shown to be responsible for hearing loss in a diverse set of nationalities. To better understand the clinical characteristics and prevalence of DFNA10, we performed genetic screening for EYA4 mutations in a large cohort of Japanese hearing loss patients. We selected 1,336 autosomal dominant hearing loss patients among 7,408 unrelated Japanese hearing loss probands and performed targeted genome enrichment and massively parallel sequencing of 68 target genes for all patients. Clinical information of cases with mutations in EYA4 was gathered and analyzed from medical charts. Eleven novel EYA4 variants (three frameshift variants, three missense variants, two nonsense variants, one splicing variant, and two single-copy number losses) and two previously reported variants were found in 12 probands (0.90%) among the 1,336 autosomal dominant hearing loss families. The audiometric configuration of truncating variants tends to deteriorate for all frequencies, whereas that of non-truncating variants tends to show high-frequency hearing loss, suggesting a new correlation between genotype and phenotype in DFNA10. The rate of hearing loss progression caused by EYA4 variants was considered to be 0.63 dB/year, as found in this study and previous reports.

Frequency and clinical features of hearing loss caused by STRC deletions

Sensorineural hearing loss is a common deficit and mainly occurs due to genetic factors. Recently, copy number variants (CNVs) in the STRC gene have also been recognized as a major cause of genetic hearing loss. We investigated the frequency of STRC deletions in the Japanese population and the characteristics of associated hearing loss. For CNV analysis, we employed a specialized method of Ion AmpliSeq^TM sequencing, and confirmed the CNV results via custom array comparative genomic hybridization. We identified 17 probands with STRC homozygous deletions. The prevalence of STRC homozygous deletions was 1.7% in the hearing loss population overall, and 4.3% among mild-to-moderate hearing loss patients. A 2.63% carrier deletion rate was identified in both the hearing loss and the control population with normal hearing. In conclusion, our results show that STRC deletions are the second most common cause of mild-to-moderate hearing loss after the GJB2 gene, which accounts for the majority of genetic hearing loss. The phenotype of hearing loss is congenital and appears to be moderate, and is most likely to be stable without deterioration even after the age of 50. The present study highlights the importance of the STRC gene as a major cause of mild-to-moderate hearing loss.

Clinical management for T1 and T2 external auditory canal cancer

OBJECTIVE

The purpose of this study was to clarify the impact of superficial parotidectomy and postoperative radiotherapy (PORT) for the surgical treatment of early stage squamous cell carcinoma (SCC) in external auditory canal (EAC).

MATERIALS AND METHODS

Thirty-seven patients with T1 (n = 14) or T2 (n = 19) SCC in EAC treated between 2000 and 2016 at Kobe University Hospital were enrolled in this study. Thirty-three patients were operated with sleeve resection or lateral temporal bone resection.

RESULTS

The 5-year overall survival and disease-specific survival rates were 95% and 100%, respectively. Surgical margin was positive in 4 patients, who were treated by PORT and have been alive without disease. Prophylactic superficial parotidectomy was simultaneously performed at the time of initial surgery in 15 patients, in whom no lymph node (LN) metastasis was observed. Among the other 22 patients, regional recurrence in parotid LN was observed in one patient, who was successfully salvaged by total parotidectomy. Potential parotid lymph node metastasis rates of T1 and T2 SCC in EAC was 0% (0/14) and 5% (1/19) respectively.

CONCLUSIONS

Complete resection without positive surgical margins is essential for the treatment of the patients with T1 and T2 ear cancers. Prophylactic superficial parotidectomy or neck dissection is not mandatory for T1 and T2 diseases, as long as precisely extent of disease is assessed preoperatively. PORT should be performed for the patients with positive surgical margins.

LEVELS OF EVIDENCE

4.

Endocytosis of CF in marginal cells of stria vascularis regulated by ROCK and MLCK signaling cascade, but not G-proteins

Objective The endocytosis of cationized feritin (CF) via a clathrin-mediated pathway is regulated by a signaling network. Marginal cells showed the active endocytosis of CF via a clathrin-mediated pathway. The internalization of receptors through this clathrin-mediated pathway is an important regulatory event in signal transduction. Numerous kinases are involved in endocytosis, and each endocytic route is subjected to high-order regulation by cellular signaling mechanisms. In this study, we investigated whether ROCK and MLCK signaling cascades and G-proteins regulate the endocytosis of CF in marginal cells of the stria vascularis. Methods CF was infused into the cochlear duct with pertussis toxin (PTX),Clostridium botulinum C3 toxin (BTX), guanosine(g-thio)-triphosphate (GTP-γS), ML-7, Y-27632. Endocytic activity was measured at 30 min after the start of infusion under an electron microscope. Results In marginal cells, CF was internalized via a clathrin-mediated pathway that depends on F-actin and microtubules (MT). Its processes were controlled by myosin light chain kinase (MLCK) and Rho-associated kinase (ROCK), but not affected by G-protein-coupled receptor (GPCR) or the RhoA signaling cascade. Conclusion Our previous study showed that the main endocytotic pathway of microperoxidase (MPO) did not depend on the Rho/ROCK molecular switch or actin/myosin motor system, but was mainly regulated by the RhoA signaling cascade. The present study results indicate that these signaling cascades regulating CF internalization completely differ from the cascades for MPO internalization.

An intensive medical care network led to successful living-donor liver transplantation in late-onset hepatic failure with disseminated Staphylococcus aureus infection

Here, we describe a 42-year-old male patient with late-onset hepatic failure (LOHF) due to acute-onset autoimmune hepatitis. At first, his response to steroid therapy was good, but hepatitis relapsed during steroid pulse therapy. Deterioration of liver function caused LOHF, and LOHF has a poor prognosis, particularly when it is complicated by infection. Systemic infection by Staphylococcus aureus resulted in a skin rash and septic pulmonary embolism, and is an absolute contraindication for liver transplantation (LT). In this treatment network, hepatologists and a transplant surgeon cooperated to overcome severe infection and their efforts led to successful transplantation. On-line hemodiafiltration is an indispensable treatment option for acute liver failure. Infection control is crucial for LT and an intensive medical care network led to successful living-donor LT.

POU4F3 mutation screening in Japanese hearing loss patients: Massively parallel DNA sequencing-based analysis identified novel variants associated with autosomal dominant hearing loss

A variant in a transcription factor gene, POU4F3, is responsible for autosomal dominant nonsyndromic hereditary hearing loss, DFNA15. To date, 14 variants, including a whole deletion of POU4F3, have been reported to cause HL in various ethnic groups. In the present study, genetic screening for POU4F3 variants was carried out for a large series of Japanese hearing loss (HL) patients to clarify the prevalence and clinical characteristics of DFNA15 in the Japanese population. Massively parallel DNA sequencing of 68 target candidate genes was utilized in 2,549 unrelated Japanese HL patients (probands) to identify genomic variations responsible for HL. The detailed clinical features in patients with POU4F3 variants were collected from medical charts and analyzed. Novel 12 POU4F3 likely pathogenic variants (six missense variants, three frameshift variants, and three nonsense variants) were successfully identified in 15 probands (2.5%) among 602 families exhibiting autosomal dominant HL, whereas no variants were detected in the other 1,947 probands with autosomal recessive or inheritance pattern unknown HL. To obtain the audiovestibular configuration of the patients harboring POU4F3 variants, we collected audiograms and vestibular symptoms of the probands and their affected family members. Audiovestibular phenotypes in a total of 24 individuals from the 15 families possessing variants were characterized by progressive HL, with a large variation in the onset age and severity with or without vestibular symptoms observed. Pure-tone audiograms indicated the most prevalent configuration as mid-frequency HL type followed by high-frequency HL type, with asymmetry observed in approximately 20% of affected individuals. Analysis of the relationship between age and pure-tone average suggested that individuals with truncating variants showed earlier onset and slower progression of HL than did those with non-truncating variants. The present study showed that variants in POU4F3 were a common cause of autosomal dominant HL.

Fatal Severe Fever with Thrombocytopenia Syndrome: An Autopsy Case Report

As of June 2014, among six patients who had severe fever with thrombocytopenia syndrome (SFTS) at our hospital, an 83-year-old man died despite receiving appropriate critical care. An autopsy revealed extensive ischemic damage of the intra-abdominal organs, including the liver, spleen, stomach and gut, due to severe celiac atherosclerotic stenosis and superior mesenteric arterial thrombosis. Many SFTS virus nucleoprotein antigen-immunoreactive cells were detected in a paraaortic node, where necrotizing lymphadenitis was seen, and in the spleen. Fewer such cells were seen in the liver, bone marrow and adrenals.

CONCLUSION

Atherosclerosis, in addition to hemophagocytic lymphohistiocytosis syndrome, can be lethal in elderly SFTS patients.

A high-fat diet delays age-related hearing loss progression in C57BL/6J mice

Objective

Age-related hearing loss (AHL), or presbycusis, is the most common sensory disorder among the elderly. We used C57BL/6J mice as an AHL model to determine a possible association between AHL and a high-fat diet (HFD).

Methods

Forty C57BL/6J mice were randomly assigned to a control or HFD group. Each group was divided into the following subgroups: 1-, 3-, 5- and 12-month groups (HFD, n = 5/subgroup; control, n = 5/subgroup). Nine CBA/N-slc mice were also used as a 12-month control (n = 5) or 12-month HFD (n = 4) group. The mice were fed a HFD or normal (control) diet throughout this study. Hearing function was evaluated at 1, 3, 5 and 12 months using auditory evoked brainstem responses (ABRs). Spiral ganglion cells (SGCs) were also counted.

Results

The elevation of ABR thresholds (at 4 and 32 kHz) at 3 and 5 months was significantly suppressed in the HFD group compared with the control groups for C57BL/6J mice. After 12 months, the elevation of ABR thresholds was significantly suppressed in the HFD group at all frequencies for C57BL/6J mice. In contrast, CBA/N-slc mice displayed opposite outcomes, as ABR thresholds at all frequencies at 12 months were significantly elevated in the HFD group compared with the control group. For the C57BL/6J mice at 12 months, SGC numbers significantly decreased in all parts of the cochleae in the control group compared with the HFD groups. In contrast, for the CBA/N-slc mice, SGC numbers significantly decreased, particularly in the upper parts of the cochleae in the HFD group compared with the control groups.

Conclusions

The elevation in ABR thresholds and SGC loss associated with aging in the HFD-fed C57BL/6J mice were significantly suppressed compared with those in the normal diet-fed mice. These results suggest that HFD delays AHL progression in the C57B/6J mice.

New MT-ND6 and NDUFA1 mutations in mitochondrial respiratory chain disorders

OBJECTIVE

Mitochondrial respiratory chain disorder (MRCD) is an intractable disease of infants with variable clinical symptoms. Our goal was to identify the causative mutations in MRCD patients.

METHODS

The subjects were 90 children diagnosed with MRCD by enzyme assay. We analyzed whole mitochondrial DNA (mtDNA) sequences. A cybrid study was performed in two patients. Whole exome sequencing was performed for one of these two patients whose mtDNA variant was confirmed as non-pathogenic.

RESULTS

Whole mtDNA sequences identified 29 mtDNA variants in 29 patients (13 were previously reported, the other 13 variants and three deletions were novel). The remaining 61 patients had no pathogenic mutations in their mtDNA. Of the 13 patients harboring unreported mtDNA variants, we excluded seven variants by manual curation. Of the remaining six variants, we selected two Leigh syndrome patients whose mitochondrial enzyme activity was decreased in their fibroblasts and performed a cybrid study. We confirmed that m.14439G>A (MT-ND6) was pathogenic, while m.1356A>G (mitochondrial 12S rRNA) was shown to be a non-pathogenic polymorphism. Exome sequencing and a complementation study of the latter patient identified a novel c.55C>T hemizygous missense mutation in the nuclear-encoded gene NDUFA1.

INTERPRETATION

Our results demonstrate that it is important to perform whole mtDNA sequencing rather than only typing reported mutations. Cybrid assays are also useful to diagnose the pathogenicity of mtDNA variants, and whole exome sequencing is a powerful tool to diagnose nuclear gene mutations as molecular diagnosis can provide a lead to appropriate genetic counseling.

Subtractive screening of genes involved in cellular senescence

We attempted to identify the genes involved in cellularsenescence, telomere maintenance and telomerase regulationthrough subtractive screening of cDNA libraries prepared froma human lung adenocarcinoma cell line A549 and its sublinesnamed A5DC7, CK and AST-9. Cell phenotypes of A5DC7, CK andAST-9 are normal cell-like, cancer cell-like and intermediate,respectively. These cell lines have different phenotypes interms of telomerase activity and telomere maintenance, andthus are thought to be useful for identifying the genesinvolved in cellular senescence and telomerase regulation. In this study, we identified 86 independent cDNA clones bysubtractive screening. Among these cDNA clones, subtractingA5DC7 cDNAs from A549 cDNAs and CK cDNAs gave 7 and 3 cDNAclones which highly and specifically expressed in tester celllines. Genes corresponding to these 10 cDNA clones mightparticipate in maintaining cancer-cell phenotypes. As aresult of database searching, each four of A549 specific cDNAclones are found to correspond to known cDNAs. Each two ofA549 specific and two of CK specific cDNA clones have highhomology to independent ESTs. Sequences having homology toeach one of A549 specific and one of CK specific cDNA cloneshave not been deposited in the Genbank database, indicatingthat these two cDNA clones are part of novel genes. Weanticipate that their involvement in telomerase regulationand/or senescence program can be clarified by functionalanalysis using each full-length cDNA.

Neural stem cells lose telomerase activity upon differentiating into astrocytes

Serum-free mouse embryo (SFME) cells were established by D. Barnes et al., and are known to be a neural stem cell line, which differentiate into astrocytes upon treatment with TGF-beta. Therefore, SFME cells is thought to be a model well suited to analyze the differentiation mechanism of neural stem cells. Until now, we have investigated the regulation mechanisms of telomerase activity and telomere length in human cancer and normal cells. Telomerase is the enzyme responsible for the synthesis and maintenance of telomere repeats located at chromosomal ends and is normally expressed in embryonic and germline cells, but not in most normal cells. Here, using SFME cells, we attempted to analyze the regulation mechanism of telomerase activity in neural stem cells and to detect a change upon differentiation into astrocytes. When SFME cells were cultured in the presence of TGF-beta, cells showed anelongated morphology and decreased its growth to 50% of control culture. Cells also expressed the glial fibrillary acidic protein (GFAP), a marker for astrocytes,indicating that TGF-beta induced differentiation in SFME cells from neural stem cells into astrocytes. At the same time,TGF-beta also inhibited telomerase activity and repressed the expression of the mouse telomerase reverse transcriptase(mTERT), demonstrating that SFME cells was vested with a finite replicative life span upon treatment with TGF-beta. To understand the mechanisms regulating mTERT levels during differentiation into astrocytes, we have estimated the expression level of c-myc, which is known to be a key molecule in activating the TERT promoter. As a result, TGF-beta-treated SFME cells were shown to repress the expression of c-myc. Furthermore, promoter analysis, using the 5'-region of the mTERT gene, which possess two E-box elements bound to c-Myc/Max, demonstrated that mTERT promoter activity greatly decreased in TGF-beta-treated SFME cells as compared to non-treated SFME cells. These suggest that c-myc might play a critical role in the expression of mTERT, and that down-regulation of c-myc dependent upon the astrocytic differentiation in SFME cells might cause the repression of mTERT in TGF-beta-treated SFME cells.

Animal models for retinitis pigmentosa induced by MNU; disease progression, mechanisms and therapeutic trials

Retinitis pigmentosa (RP) is a group of inherited neurodegenerative diseases in humans characterized by loss of photoreceptor cells leading to visual disturbance and eventually to blindness. A single systemic administration of N-methyl-N-nitrosourea (MNU) causes retinal degeneration in various animal species. The retinal degeneration is highly reproducible, and the photoreceptor cell loss occurs within seven days after MNU administration via apoptosis resembling human RP. Here, we describe the disease progression, disease mechanisms, and therapeutic trials of MNU-induced retinal degeneration.

Role of fatty acids in malignancy and visual impairment: epidemiological evidence and experimental studies

International variation in breast and colon cancer incidence is positively related to total fat intake. However, total fat consists of different fatty acid families, e.g., saturated fatty acids (SFAs), monounsaturated fatty acids (MUFAs), and n-3 and n-6 polyunsaturated fatty acids (PUFAs). Epidemiological evidence and experimental studies suggest that these fatty acid families have different effects on breast and colon carcinogenesis. Therefore the action of each fatty acid on carcinogenesis should be evaluated separately. Although it is difficult to establish firm conclusions on the effect of each fatty acid in human epidemiological studies, experimental studies on animals and cultured cells suggest that n-6 PUFAs (linoleic acid and arachidonic acid) may have a tumor promoting effect, while n-3 PUFAs (eicosapentaenoic acid, docosahexaenoic acid and alpha-linolenic acid) and conjugated fatty acids (CFAs; a mixture of positional and geometric isomers of PUFAs with conjugated double bonds) exert an inhibitory effect on tumor growth. SFAs such as palmitic acid and stearic acid show little or no tumor promoting effect, and the action of oleic acid, a MUFA, is inconclusive. In addition to regulation of abnormal cell growth seen in cancers, fatty acids also control cell loss seen in degenerative eye diseases, such as degeneration of lens material in cataract and degeneration of photoreceptor cells in retinitis pigmentosa. Experiments suggest that n-6 PUFAs cause deleterious effects, while n-3 PUFAs result in beneficial effects on the lens and retina. In particular, docosahexaenoic acid is known to be effective in rescuing photoreceptor cells from damage. Thus, understanding the function of each fatty acid is likely to be important for making progress in treating these and other diseases.

TAK1 represses transcription of the human telomerase reverse transcriptase gene

In human cells, telomerase activity is tightly regulated by the expression of its catalytic subunit, namely, the human telomerase reverse transcriptase (hTERT). However, the molecular mechanisms involved in the regulation of hTERT expression have not been completely clarified. We have previously reported that transforming growth factor beta (TGF-beta) represses the expression of the hTERT gene. In the present study, we demonstrated that TGF-beta-activated kinase 1 (TAK1), originally identified as a mitogen-activated kinase kinase kinase, represses the hTERT core promoter activity in an E-box-independent manner, and it also represses the transcription of the hTERT gene in human lung adenocarcinoma cell line, A549 cells. This TAK1-induced repression was found to be caused by the recruitment of histone deacetylase to Sp1 at the hTERT promoter and a consequent reduction in the amount of acetylated histone H4 at the hTERT promoter. Finally, we demonstrated that TAK1 induces cellular senescence programs in normal human diploid cells. Thus, we assume that TAK1 triggers the repression mechanisms of the hTERT gene as a result of evoking cellular senescence programs. Considered together, TAK1 is thought to play a causative role in the determination of a finite replicative lifespan of normal and cancer cells.

Human β-defensin-3 induction in H pylori-infected gastric mucosal tissues

AIM: To examine human β-defensin-3 (hBD-3) expression in inflamed gastric mucosal tissues or MKN45 gastric cancer cells with or without H pylori infection for better understanding the innate immune response to H pylori.

METHODS: We used reverse transcription-polymerase chain reactions and immunohistochemistry to examine hBD-3 expression in inflamed gastric mucosal tissues or MKN45 gastric cancer cells with or without H pylori. Effects of hBD-3 against H pylori were also evaluated.

RESULTS: The mean mRNA expression of hBD-3 in H pylori-positive specimens was significantly higher than that in H pylori-negative specimens (P = 0.0002, Mann-Whitney). In addition, unlike uninfected samples, 8 of 15 (53.33%) infected mucosal samples expressed hBD-3 protein. H pylori dose-dependently induced mRNA expression of hBD-3 in MKN45 cells, an effect inhibited by adding anti-toll-like receptor (TLR)-4 antibody. HBD-3 protein completely inhibited H pylori growth.

CONCLUSION: Our results suggest that like hBD-2, hBD-3 may be involved in the pathophysiology of H pylori-induced gastritis.

Existence of a Threshold for Induction of Aberrant Crypt Foci in the Rat Colon with Low Doses of 2-Amino-1-methyl-6-phenolimidazo[4,5-b]pyridine

Until recently it has been generally considered that genotoxic carcinogens have no threshold in exerting their potential for cancer induction. However, the nonthreshold theory can be challenged with regard to assessment of cancer risk to humans. In the present study we show that a food derived, genotoxic hepatocarcinogen, 2-amino-1-methyl-6-phenolimidazo[4,5-b]pyridine (PhIP), does not induce aberrant crypt foci (ACF) as preneoplastic lesions at low dose (below 50 ppm) or 8-hydroxy-2'-deoxyguanosine (below 400 ppm) in the rat colon. Moreover PhIP-DNA adducts were not formed at the lowest dose (below 0.01 ppm). Thus, the dose required to initiate ACF is approximately 5000 times higher than that needed for adduct formation. The results imply a no-observed effect level (existence of a threshold) for colon carcinogenesis by a genotoxic carcinogen.

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.

Pyrazinamide resistance associated with pncA gene mutation in Mycobacterium tuberculosis in Japan

Thirty Japanese clinical isolates of Mycobacterium tuberculosis were analysed by pyrazinamide susceptibility testing and pyrazinamidase assay, as well as polymerase chain reaction for single-strand conformational polymorphism and direct sequencing of the gene encoding pyrazinamidase (pncA). All sensitive isolates showed pyrazinamidase activity and a wild-type pncA gene, but three resistant isolates had pncA gene mutations and lacked pyrazinamidase activity. The latter isolates showed a minimum inhibitory concentration of at least 100 mg/l by the 7H10 agar proportion method and 400 mg/l by the 7H9 liquid medium method. Isolate 28 showed T-to-C change at position 11, leading to Leu4 --> Ser substitution; isolate 29 had an 8-bp deletion from position 382; and isolate 30 had A-to-C change at position 29, leading to Gln10 --> Pro substitution. The deletion has not been described previously. This is the first demonstration of pncA gene mutations in PZA-resistant M. tuberculosis strains isolated from Japanese patients.

Determination of trace amounts of boron in steel by reversed-phase high-performance liquid chromatography with azomethine-H as a precolumn derivatizaion agent

The determination of trace amounts of boron in steel by reversed-phase high-performance liquid chromatography (HPLC) is described. As a derivatizing reagent for the HPLC determination of boron, 8-hydroxy-1-(salicylideneamino)-3,6-naphtalenedisulfonic acid (azomethine-H) was used with a spectrophotometric detection. A peak of boron-azomethine-H chelate was resolved from other peaks using an acetonitrile-water (29 + 71 m/m) eluent containing 8 x 10(-3) mol kg(-1) tetrabutylammonium bromide and 5 x 10(-3) mol kg(-1) acetate buffer (pH 5.0). The lower determination limit (10sigma) of boron was 3.3 x 10(-8) mol dm(-3) for a solution injected into HPLC, which is translated to 0.09 microgB/g when 0.1 g of a steel sample was subjected to the analysis. The analytical results of certified steel samples were in good agreement with the guaranteed values. The addition of ethylenediamine-N,N,N',N'-tetraacetate as a masking agent for the iron(III) matrix with the optimized eluent enables one to achieve the direct determination of trace amounts of boron in such steel sample solutions without any tedious matrix removal or preconcentration.

[Nationwide sensitivity surveillance of various antibiotic activities against bacteria isolated from patients with severe infections]

The susceptibility of 3,058 bacterial strains isolated between January and March, 1997 from patients with severe infections in Japan to ciprofloxacin and other injectable antimicrobial agents was measured using broth microdilution method. Methicillin-resistant Staphylococcus aureus (MRSA) strains were generally sensitive to vancomycin, teicoplanin and arbekacin, and resistant to CPFX and other antibacterial agents. MIC90 of CPFX against Streptococcus pneumoniae, to which MIC of ampicillin was more than 4 micrograms/mL, was below 2 micrograms/mL. PRSP (Penicillin resistant S. pneumoniae), which was also resistant to cephalosporins and carbapenems, showed no cross-resistance to CPFX. The susceptibility of Gram-negative bacteria to CPFX was as high as that to carbapenems. Especially, MIC90 against Pseudomonas aeruginosa was 2 micrograms/mL. 3 strains of isolated 446 P. aeruginosa strains had blaIMP gene. CPFX and pazufloxacin demonstrated good susceptibility with 0.25 microgram/mL of MIC to 2 strains of these 3 strains. The susceptibility rate of the most common isolates from patients suffering from lower respiratory tract infections excluding MRSA to CPFX was more than 80% (indication: % strains < pneumonia break point).

Distribution of aminoglycoside resistance genes in recent clinical isolates of Enterococcus faecalis, Enterococcus faecium and Enterococcus avium

Aminoglycoside modifying enzymes (AMEs) are major factors which confer aminoglycoside resistance on bacteria. Distribution of genes encoding seven AMEs was investigated by multiplex PCR for 279 recent clinical isolates of enterococci derived from a university hospital in Japan. The aac(6')-aph(2"), which is related to high level gentamicin resistance, was detected at higher frequency in Enterococcus faecalis (42.5%) than in Enterococcus faecium (4.3%). Almost half of E. faecalis and E. faecium isolates possessed ant(6)-Ia and aph(3')-IIIa. The profile of AME gene(s) detected most frequently in individual strains of E. faecalis was aac(6')aph(2") + ant(6)-Ia + aph(3')-IIIa, and isolates with this profile showed high level resistance to both gentamicin and streptomycin. In contrast, AME gene profiles of aac(6')-Ii+ ant(6)-Ia+aph(3')-IIIa, followed by aac(6')-Ii alone, were predominant in E. faecium. Only one AME gene profile of ant(6)-Ia+aph(3')-IIIa was found in Enterococcus avium. The ant(4')-Ia and ant(9)-Ia, which have been known to be distributed mostly among Staphylococcus aureus strains, were detected in a few enterococcal strains. An AME gene aph(2")-Ic was not detected in any isolates of the three enterococcal species. These findings indicated a variety of distribution profiles of AME genes among enterococci in our study site.

Molecular cloning and functional characterization of two kinds of betaine-aldehyde dehydrogenase in betaine-accumulating mangrove Avicennia marina (Forsk.) Vierh

Glycinebetaine is an important osmoprotectant in bacteria, plants, and animals, but only little information is available on the synthesis of glycinebetaine in tree plants. Among four mangrove species, glycinebetaine could be detected only in Avicennia marina. Pinitol was the main osmoprotectant in the other three species. The level of glycinebetaine in A. marina increased under high salinity. Betaine-aldehyde dehydrogenase (BADH) was detected in all four species, but choline monooxygenase could not be detected. A cDNA library was constructed from the leaves of A. marina. Two kinds of BADH cDNAs were isolated, one homologous to the spinach chloroplast BADH, and the other with unique residues SKL at the end of C-terminus. The BADH transcription levels of the former were higher than those of the latter. The levels of the former BADH increased at high salinity whereas those of the latter were independent of salinity. BADHs were expressed in Escherichia coli and purified. Two kinds of A. marina BADHs exhibited similar kinetic and stability properties, but were significantly different from those of spinach BADH. A. marina BADHs efficiently catalyzed the oxidation of betainealdehyde, but not the oxidation of omega-aminoaldehydes and were more stable at high temperature than the spinach BADH.

Spectrophotometric characterization of diazacrown ethers having two carbodithioate groups

Diazacrown ethers having two carbodithioate groups were synthesized, and their spectrophotometric properties were studied. Diammonium 1,4,10,13-tetraoxa-7,16-diazacycrooctadecane-N,N'-bis(carbodithioate) (DA18CC) and ammonium 1,4,10-trioxa-7,13-diazacycropentadecane-N,N'-bis(carbodithioate) (DA15CC) reacted with most heavy-metal ions through their two carbodithioate groups, and also reacted with alkali-metal ions or alkaline earth-metal ions through their diazacrown rings. Although the UV-VIS absorption spectra of DA18CC and DA15CC were hardly influenced by the addition of alkali-metal ions or alkaline earth-metal ions, the spectra of some heavy-metal chelates of DA18CC and DA15CC were influenced. The composition ratio (metal:ligand) of Cu(II) and Pb(II) chelates of DA18CC and DA15CC was altered from 1:1 to 1:2 by the addition of alkali-metal ions or alkaline earth-metal ions. It is suggested that the change in the absorption spectra and the composition ratio of the chelates can be attributed to an alteration of the equilibrium among species of the heavy-metal chelates of DA18CC and DA15CC due to the coordination of alkali-metal ions or alkaline earth-metal ions into the diazacrown ring.

[Activities of antimicrobial agents against 5,180 clinical isolates obtained from 26 medical institutions during 1998 in Japan. Levofloxacin--Surveillance Group]

The surveillance study was conducted to determine the antimicrobial activity of fluoroquinolones (ofloxacin, levofloxacin, ciprofloxacin, tosufloxacin) and other 20 antimicrobial agents against 5,180 clinical isolates obtained from 26 medical institutions during 1998 in Japan. The resistance to fluoroquinolones was remarkable in Enterococci, methicillin-resistant staphylococci and Pseudomonas aeruginosa from UTI. However, many of the common pathogens such as Streptococcus pneumoniae including penicillin-resistant isolates, methicillin-susceptible Stahylococcus aureus, Moraxella catarrhalis, the family of Enterobacteriaceae, Haemophilus influenzae including ampicillin-resistant isolates have been kept to be susceptible to fluoroquinolones. About 90% of P. aeruginosa isolates from RTI were susceptible to fluoroquinolones. In conclusion, the results from this surveillance study suggest that fluoroquinolones are useful in the treatment of various bacterial infections including respiratory infections.

[Changes in the antibacterial activity of chemotherapeutic agents (especially carbapenems) for 10 species of clinical isolates between 1994 and 1996. Surveillance group of the sensitivities of clinical isolates to antibacterial agents]

During October and December of each year of from 1994 to 1996, 3,849 strains of 10 species of bacteria were isolated from clinical materials in 21 institutions nationwide. The minimum inhibitory concentrations (MICs) for these bacteria of four carbapenems (imipenem [IPM], panipenem [PAPM], meropenem [MEPM], and biapenem [BIPM]) and other representative antibacterial agents were measured to investigate annual changes in antibacterial activity. Carbapenems showed potent activity against methicillin-sensitive S. aureus (MSSA), S. pneumoniae, E. faecalis, H. influenzae, E. coli, K. pneumoniae, E. cloacae, S. marcescens, and the B. fragilis group, with the activity being stable. However, these drugs showed weak activity against methicillin-resistant S. aureus (MRSA) and P. aeruginosa. The antibacterial activity (MIC90) against the tested organisms generally remained stable. Particularly, there was annual improvement of the MIC90 values of IPM and BIPM for S. pneumoniae, as well as the values of IPM and PAPM for H. influenzae, and those of IPM, PAPM, and BIPM for S. marcescens. On the other hand, the activity of carbapenems (including IPM) against MRSA was not necessarily strong, but there was annual improvement of MIC90 values.