[A case of irreversible metronidazole encephalopathy during liver abscess treatment]

Metronidazole (MNZ) is a widely used drug for protozoan and anaerobic infections. The continuous use of MNZ causes various neurological symptoms, such as cerebellar ataxia, visual disturbance, vestibulocochlear symptoms, gait disturbance, dysarthria, and epileptic seizures of unknown cause, named MNZ-induced encephalopathy (MIE), in rare cases. MIE is a reversible disease that often improves within a few days of MNZ discontinuation, but irreversible neurological symptoms rarely remain. Herein, we report a case of MIE that developed during MNZ administration for a liver abscess, causing prolonged unconsciousness and death even after drug discontinuation. An 85-year-old female patient complained of fever, elevated liver enzymes, and a multifocal abscess in the right hepatic lobe, as seen on computed tomography. Percutaneous transhepatic abscess drainage and antibiotic therapy were initiated. The causative agent of the liver abscess could not be identified, thus meropenem was started, which demonstrated no inflammation improvement, thus oral MNZ was added. The inflammation recurred when MNZ was discontinued, and the patient continued taking MNZ. Vomiting, upper limb tremors, consciousness disturbance, and convulsions appeared on day 46 (total dose of MNZ 73.5mg), and the patient was hospitalized. T2-weighted, diffusion-weighted, and FLAIR head magnetic resonance imaging (MRI) revealed symmetrical abnormal high-signal areas in the cerebellar dentate nucleus, corpus callosum, cerebral white matter, and periventricular areas. MIE was diagnosed based on the patient's course and MRI images, and MNZ was discontinued. The patient continued to suffer from impaired consciousness and convulsions after MNZ discontinuation and died due to aspiration pneumonia. Suggestively, MIE development is related to long-term MNZ administration, poor nutrition, liver disease, underlying diseases (such as advanced cancer), and serious complications. A systematic review of MIE cases revealed that 4.8-5.9% of the patients demonstrated little improvement of symptoms after MNZ discontinuation, and some deaths were reported. Patients with poor prognosis were often suffering from impaired consciousness and convulsions. Furthermore, impaired consciousness was the most common residual symptom. Abnormal signals in characteristic areas, such as the dentate nucleus cerebri and corpus callosum, on head MRI are useful for MIE diagnosis, especially in patients with abnormal findings in the cerebral white matter, which is associated with a poor prognosis. We should pay close attention to the onset of MIE when MNZ is administered.

Efficacy and safety of glecaprevir and pibrentasvir combination therapy in old-aged patients with chronic hepatitis C virus infection

Objective: Combination therapy with glecaprevir and pibrentasvir (G/P) has been shown to provide a sustained virologic response (SVR) rate of >97% in patients with chronic hepatitis C virus (HCV) infection in the first published real-world Japanese data. However, a recently published study showed that the treatment was often discontinued in patients ≥75 years old, resulting in low SVR in intention-to-treat (ITT) analysis. Thus, our aim was to evaluate real-world data for G/P therapy in patients ≥75 years of age, the population density of which is high in “rural” regions.

Patients and Methods: We conducted a multicenter study to assess the efficacy and safety of G/P therapy for chronic HCV infection, in the North Kanto area in Japan.

Results: Of the 308 patients enrolled, 294 (95.5%) completed the treatment according to the protocol. In ITT and per-protocol analyses, the overall SVR12 rate was 97.1% and 99.7%, respectively. The old-aged patients group consisted of 59 participants, 56 of whom (94.9%) completed the scheduled protocol. Although old-aged patients tended to have non-SVR factors such as liver cirrhosis, history of HCC, and prior DAA therapies, the SVR12 rates in old-aged patients were 98.3% and 100% in the ITT and PP analyses, respectively. Of 308 patients enrolled, adverse events were observed in 74 patients (24.0%), with grade ≥3 events in 8 patients (2.6%). There was no significant difference in any grade and grade ≥3 adverse events between the old-aged group and the rest of the study participants. Only one patient discontinued the treatment because of adverse events.

Conclusion: G/P therapy is effective and safe for old-aged patients.

Usefulness of Gd-EOB-DTPA-enhanced MRI for evaluating the potential for early development of hepatocellular carcinoma after HCV eradication by direct-acting antiviral treatment

Objective: The development of hepatocellular carcinoma (HCC) is not uncommon in patients who achieve eradication of the hepatitis C virus through direct-acting antiviral (DAA) treatment. The aim of this study was to identify the patients at high risk for novel HCC development after a sustained virologic response (SVR) by DAA treatment.

Patients and Methods: A total of 518 patients with no history of HCC treatment and who achieved SVR by DAA treatment were evaluated retrospectively. The correlations between HCC development and the patients’ characteristics were evaluated. For patients who underwent gadolinium-ethoxybenzyl-diethylenetriamine pentaacetic acid (Gd-EOB-DTPA)-enhanced magnetic resonance imaging (MRI) or dynamic contrast-enhanced computed tomography, the relationship between the imaging findings and subsequent HCC development was also assessed.

Results: HCC developed newly in 22 patients, and the 1-year and 3-year cumulative HCC rates were 2.0% and 8.5%, respectively. In multivariate analysis, a FIB-4 index >4.0 and a post-treatment α-fetoprotein >4.0 ng/ml were significant risk factors for HCC. In 26 of 118 patients who underwent an MRI before DAA treatment, a non-hypervascular hypo-intense nodule was seen in the hepatobiliary phase, and in 6 of 182 patients who underwent a CT, a non-hypervascular hypo-enhanced nodule was seen in the delayed phase. The sensitivity and specificity of the MRI-positive findings for the subsequent development of HCC were 0.92 and 0.87, respectively, and those of the CT were 0.40 and 0.99, respectively. In multivariate analysis of patients who underwent an MRI, a non-hypervascular hypo-intense nodule was the only factor that was significantly related to HCC development (HR 32.4, p = 0.001).

Conclusion: Gd-EOB-DTPA-enhanced MRI was found to be reliable for risk evaluation of subsequent HCC development in patients after SVR by DAA treatment. Patients with a non-hypervascular hypo-intense nodule need more careful observation for incident HCC.

No Regional Disparities in Sofosbuvir Plus Ribavirin Therapy for HCV Genotype 2 Infection in Tochigi Prefecture and Its Vicinity

Objective Regional disparities were observed in the outcomes of interferon (IFN)-based therapy for chronic hepatitis C virus (HCV) infection in a Japanese nationwide study. However, whether or not these regional disparities are observed in the outcomes of direct-acting antiviral drugs, including sofosbuvir (SOF) plus ribavirin (RBV) therapy, remains unclear. Methods We conducted a multicenter study to assess the efficacy of SOF plus RBV therapy for HCV genotype 2 infection in Tochigi Prefecture and its vicinity, in which IFN-based therapy yielded a low sustained virologic response (SVR) rate. In addition, we divided Tochigi Prefecture into six regions to examine regional disparities in the SVR. Patients We enrolled patients with chronic HCV genotype 2 infection. Results Of the 583 patients enrolled, 569 (97.6%) completed the treatment, and 566 (97.1%) also complied with post-treatment follow-up for 12 weeks. The overall SVR12 rate was 96.1% by per protocol and 93.7% by intention-to-treat analyses. No marked differences were observed in the SVR12 between subjects ≥65 and <65 years of age. Although large gaps were observed in the characteristics of patients and accessibility to medical resources, there was no significant difference in the SVR12 rate among the six regions in Tochigi Prefecture. Conclusion SOF plus RBV therapy was effective for HCV genotype 2 infection in an area where IFN-based therapy had previously shown unsatisfactory results. In addition, no regional disparities in the SVR12 were observed in Tochigi Prefecture.

Short-Term Results of Laparoscopic Radiofrequency Ablation Using a Multipolar System for Localized Hepatocellular Carcinoma

BACKGROUND AND AIM

Multipolar radiofrequency ablation (RFA) is feasible for the treatment of hepatocellular carcinoma (HCC) for which a large ablative area is planned, and it imposes a light physical burden on patients. Multipolar RFA via the percutaneous approach is performed in the majority of cases, but the efficacy of multipolar RFA with a laparoscopic approach has rarely been studied. This study aimed to evaluate the efficacy and safety of multipolar laparoscopic RFA (LRA) for localized HCC over the short term.

METHODS

From January 2014 to January 2016, 77 consecutive patients with 130 HCCs treated by multipolar LRA were assessed. One to three bipolar needle applicators were inserted under laparoscopic ultrasonography guidance, regardless of tumor location. We intended to achieve parallel insertions and no-touch ablation as much as possible.

RESULTS

The median size of the main tumor was 22 mm (range, 10-42 mm). The median follow-up time was 13.6 months (range, 3.1-24.8 months). In all cases, a sufficient ablative area was obtained as planned, without thermal injury of adjacent organs. During the follow-up period, all patients were alive with no local tumor progression, while intrahepatic recurrence distant from the primary site occurred in 7 patients. The 2-year local tumor progression-free survival rate and overall cancer-free survival rate were 100 and 81.6%, respectively. There were no procedural major complications caused prolonging the hospitalization, and all patients were discharged without subjective symptoms 4-7 days after LRA.

CONCLUSIONS

Multipolar LRA was efficacious in the treatment of localized HCCs by safely achieving a good ablative area.

Full genome analysis of Philippine indigenous subgenotype IA hepatitis A virus strains from Japanese patients with imported acute hepatitis A

AIM

Hepatitis A virus (HAV) is the most common cause of infectious hepatitis worldwide. Although hepatitis A cases imported from South-East Asian countries, including the Philippines, have been reported in Japan, the molecular epidemiological data have been limited for these HAV-endemic countries.

METHODS

The full-length genomic sequences of HAV isolates were determined and subjected to the phylogenetic analyses.

RESULTS

The HAV isolates (HA12-0796 and HA12-0938) obtained from two Japanese patients who developed acute hepatitis A in July 2012, 1 month after traveling to the Philippines, where they consumed undercooked shellfish, differed by only one nucleotide (nt) over the entire genome. These HAV isolates of genotype IA were 99.1-99.5% identical within 228-237 nt to those recovered from river water in the Philippines, suggesting that the HA12-0796 and HA12-0938 isolates represent HAV circulating in the Philippines. HAV isolates belonging to one of the two IA sublineages (IA-2) which were implicated in some of the mini-epidemics in 2010 in Japan are hypothesized to be connected with the Philippines. In support of this speculation, the present IA isolates (HA12-0796 and HA12-0938) shared 98.8% identity over the entire genome with one IA-2 isolate (HAJIH-Fukuo10) recovered from a Japanese female who developed a domestic HAV infection during the mini-epidemics. In the phylogenetic tree constructed based on the entire genome, these three isolates (HA12-0796, HA12-0938 and HAJIH-Fukuo10) segregated into a cluster with a bootstrap value of 100%.

CONCLUSION

These results indicate that HAV isolates belonging to the IA-2 lineage might have been imported from the Philippines.

HapMap SNP Scanner: an online program to mine SNPs responsible for cell phenotype

Minor histocompatibility (H) antigens are targets of graft-vs-host disease and graft-vs-tumor responses after human leukocyte antigen matched allogeneic hematopoietic stem cell transplantation. Recently, we reported a strategy for genetic mapping of linkage disequilibrium blocks that encoded novel minor H antigens using the large dataset from the International HapMap Project combined with conventional immunologic assays to assess recognition of HapMap B-lymphoid cell line by minor H antigen-specific T cells. In this study, we have constructed and provide an online interactive program and demonstrate its utility for searching for single-nucleotide polymorphisms (SNPs) responsible for minor H antigen generation. The website is available as 'HapMap SNP Scanner', and can incorporate T-cell recognition and other data with genotyping datasets from CEU, JPT, CHB, and YRI to provide a list of candidate SNPs that correlate with observed phenotypes. This method should substantially facilitate discovery of novel SNPs responsible for minor H antigens and be applicable for assaying of other specific cell phenotypes (e.g. drug sensitivity) to identify individuals who may benefit from SNP-based customized therapies.

In hydrolyzed cow's milk Helicobacter pylori becomes nonculturable and the growth of Salmonella typhi and Escherichia coli is inhibited

The colony forming unit (CFU) of H. pylori is reduced rapidly in lipase hydrolyzed cow's milk and a similar reduction was found in a physiological saline solution when it was supplemented with soluble C4 to C10 fatty acids of milk fat composition. Slight CFU decreases were observed for E. coli and S. typhi in hydrolyzed milk buffered to pH 3, while the counts in milk and physiological saline solution at pH 3 stayed almost unchanged for 24 h. E. coli proliferated in glucose-peptone medium, better at pH 4.7 than at pH 3. On the other hand, supplementation of the medium with soluble fatty acids of milk composition completely inhibited growth for 32 h. Supplementation of the medium with fatty acids reduced the growth of S. typhi to approximately 1/20 at pH 4.7. Therefore, milk hydrolyzed by gastric lipase may damage H. pylori, producing a nonculturable state. With E. coli and S. typhi, hydrolyzed milk does not induce inactivation to a nonculturable state but inhibits their proliferation potently. The latter is considered to be a state prior to VBNC (viable but nonculturable). However, the antibiotic effect will disappear when the fatty acids are absorbed by the intestine.

Effect of oxygen-enriched aeration on regeneration of rice (Oryza sativa L.) cell culture

The effect of the oxygen concentration in the aeration gas on regeneration from rice cells in bioreactor cultures was investigated. The efficiency of regeneration in cultures aerated with over 40% oxygen was higher than that in a flask culture. In the case of a culture in which the dissolved oxygen(DO) was saturated by aeration with air, the efficiency of regeneration was less than the half that of cultures aerated with 40% oxygen. In cultures with the DO levels controlled at 8,10 and 12 mg/ℓ, the efficiency of regeneration was highest at 12 mg/ℓ. In the oxygenenriched cultures, although cell aggregation was observed and the color of plantlets was relatively pale, more than 90% of them grew into healthy plants.

Effect of culture methods on the regeneration of albino rice (Oryza sativa L.) plantlets

In our study, we investigated the effects of regeneration conditions on both green and albino rice plants (Oryza sativa L.). The regeneration frequency of an albino cell line was compared to a normal cell line obtained from mature seed under two kinds of culture conditions; namely, the static culture on semi-solid regeneration medium and the suspension culture in liquid regeneration medium. The albino cell line, from which only albino plantlets were regenerated, was induced from the albino leaf segments. There were no significant differences in the regeneration frequencies between normal and albino calli on the semisolid regeneration medium. On the other hand, the frequency of regeneration of albino calli was significantly lower than that of the control specifically in the liquid regeneration medium.

Simple dehydration treatment promotes plantlet regeneration of rice (Oryza sativa L.) callus

To increase plantlet regeneration frequency, rice callus was dehydrated in a Petri dish with a single layer of filter paper prior to transfer to the regeneration medium. With a 24 h dehydration treatment, the regeneration frequency was increased to 47 %, while the regeneration frequency of the untreated control was less than 5 %. This relatively simple method provides an alternative method for improving the regeneration frequency of rice callus.

[Prevention of renal toxicity of cisplatin by administration of bismuth subnitrate]

The effect of pretreatment with bismuth subnitrate (BSN) for prevention of the renal toxicity of cisplatin (CDDP) was examined in 44 patients with lung cancer (43 non-small cell and one small cell lung cancer). In non-small cell lung cancer cases, the effect of the antitumor activity of chemotherapeutic drugs was observed in 62% of patients pretreated with BSN, and 42% in the group without pretreatment with BSN. No antitumoral activity of chemotherapeutic drugs was suppressed by treatment with BSN. In the group without pretreatment of BSN, serum creatinine and BUN were in proportion to the number of administrations of chemotherapeutic drugs. On the other hand, no renal toxicity was shown in the group with pretreatment by BSN. No protective effect against myelosuppression with pretreatment by BSN was demonstrated, perhaps because of the influence of anti-cancer drugs apart from CDDP.

[An autopsy case of lung cancer in a young adult dwarf]

A 31-year-old man with peripheral squamous cell carcinoma is reported. By nature he was very small. On admission he was 140 cm tall, weighed 28 kg, and was complaining of chest pain of five years duration. A giant tumor in the right lung was found to be moderately differentiated squamous cell carcinoma. He also had congenital anomalies, such as crossed ectopic kidney with fusion, café-au-lait spots, inguinal hernia, simian line, etc. He had never been exposed to cancer-causing agents. In conclusion, genetic factors related to intrauterine growth retardation might have been linked to his oncodevelopmental mechanisms.