Comparative efficacy evaluation of disinfectants against severe acute respiratory syndrome coronavirus-2.

BACKGROUND: Disinfection is one of the most effective ways to block the rapid transmission of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). Due to the prolonged coronavirus disease 2019 (COVID-19) pandemic, disinfectants have become crucial to prevent person-to-person transmission and decontaminate hands, clothes, facilities and equipment. However, there is a lack of accurate information on the virucidal activity of commercial disinfectants. AIM: To evaluate the virucidal efficacy of 72 commercially available disinfectants constituting 16 types of ingredients against SARS-CoV-2. METHODS: SARS-CoV-2 was tested with various concentrations of disinfectants at indicated exposure time points as recommended by the manufacturers. The 50% tissue culture infectious dose assay was used to calculate virus titre, and trypan blue staining and CCK-8 were used to assess cell viability after 3-5 days of SARS-CoV-2 infection. FINDINGS: This study found that disinfectants based on 83% ethanol, 60% propanol/ethanol, 0.00108-0.0011% sodium dichloroisocyanurate and 0.497% potassium peroxymonosulfate inactivated SARS-CoV-2 effectively and safely. Although disinfectants based on 0.05-0.4% benzalkonium chloride (BAC), 0.02-0.07% quaternary ammonium compound (QAC; 1:1), 0.4% BAC/didecyldimethylammonium chloride (DDAC), 0.28% benzethonium chloride concentrate/2-propanol, 0.0205-0.14% DDAC/polyhexamethylene biguanide hydrochloride (PHMB) and 0.5% hydrogen peroxide inactivated SARS-CoV-2 effectively, they exhibited cytotoxicity. Conversely, disinfectants based on 0.04-4% QAC (2:3), 0.00625% BAC/DDAC/PHMB, and 0.0205-0.14% and 0.0173% peracetic acid showed approximately 50% virucidal efficacy with no cytotoxicity. Citric acid (0.4%) did not inactivate SARS-CoV-2. CONCLUSION: These results indicate that most commercially available disinfectants exert a disinfectant effect against SARS-CoV-2. However, re-evaluation of the effective concentration and exposure time of certain disinfectants is needed, especially citric acid and peracetic acid.

Whole-exome sequencing study reveals common copy number variants in protocadherin genes associated with childhood obesity in Koreans.

Recently, the prevalence of childhood obesity has significantly increased in industrialized countries, including Korea, and now controlling obesity is becoming an economic burden. However, knowledge of the risk factors associated with obesity is still limited. In this study, we aimed to discover additional obesity-associated loci in children. To achieve this, we conducted an exome-wide association analysis of copy number variation (CNV) using whole-exome sequencing (WES) data from a total of 102 cases and 86 controls. We newly identified a CNV locus that overlapped two protocadherin genes, PCDHB7 and PCDHB8, which are brain function-related genes (P-value=6.40 × 10-4, odds ratio=2.2189). A subsequent replication analysis using WES data from 203 obese and 291 normal weight children showed that this CNV region satisfied the genome-wide significance standard (Fisher's combined P-value=3.76 × 10-5). Moreover, correlation test using 199 additional samples supported significant association between CNV and increased body mass index. This region also showed a meaningful association with 273 cases and 2596 controls in adult samples. Our findings suggest that differences in the common CNV region at 5q31.3 may have an impact on the pathophysiology of obesity.

MR findings of the spinal paraganglioma : report of three cases.

Extraadrenal paragangliomas involving the spine is less common and usually takes the form of intradural compression of the cauda equina. The authors report three cases of spinal paragangliomas resulting in extradural spinal cord compression and their MR findings. The MR imaging revealed a well-demarcated extradural mass with low to intermediate signal intensity on T1-weighted images and intermediate to high signal intensity on T2-weighted images compared to paravertebral muscles. After Gd-DTPA administration, heterogeneous and intense enhancement was found. Multiple punctate and serpiginous structures of signal void due to high-velocity flow were noted around and within the tumors on all sequences. In one case, the signal void structures were well corresponded with feeding arteries on angiography. These may be the characteristic findings of the extraadrenal paraganglioma involving the spine.

Expressed sequence tags (ESTs) analysis of Acanthamoeba healyi.

Randomly selected 435 clones from Acanthamoeba healyi cDNA library were sequenced and a total of 387 expressed sequence tags (ESTs) had been generated. Based on the results of BLAST search, 130 clones (34.4%) were identified as the genes encoding surface proteins, enzymes for DNA, energy production or other metabolism, kinases and phosphatases, protease, proteins for signal transduction, structural and cytoskeletal proteins, cell cycle related proteins, transcription factors, transcription and translational machineries, and transporter proteins. Most of the genes (88.5%) are newly identified in the genus Acanthamoeba. Although 15 clones matched the genes of Acanthamoeba located in the public databases, twelve clones were actin gene which was the most frequently expressed gene in this study. These ESTs of Acanthamoeba would give valuable information to study the organism as a model system for biological investigations such as cytoskeleton or cell movement, signal transduction, transcriptional and translational regulations. These results would also provide clues to elucidate factors for pathogenesis in human granulomatous amoebic encephalitis or keratitis by Acanthamoeba.

Effect of arachidonic acid metabolic inhibitors on hypoxia/reoxygenation-induced renal cell injury.

The present study was undertaken to examine the role of arachidonic acid (AA) metabolites in hypoxia/reoxygenation (H/R)-induced renal cell injury in rabbit renal cortical slices using AA metabolic inhibitors. Inhibitors of cyclooxygenase (indomethacin and diclofenac sodium) and lipoxygenase pathways (nordihydroguaiaretic acid, caffeic acid, and eicosapentaenoic acid) reduced H/R-induced LDH release in a dose-dependent manner, whereas an inhibitor of cytochrome P-450 monooxygenase pathway ethoxyresorufin was not effective. AA increased LDH release in control slices, and the effect was not altered by indomethacin and nordihydroguaiaretic acid. The protective effect of indomethacin was not affected by addition of PGE2, a main product of cyclooxygenase pathway in the kidney. H2O2-induced LDH release was prevented by inhibitors of lipoxygenase but not by inhibitors of cyclooxygenase and cytochrome P-450 monooxygenase H/R-induced LDH release was not altered by iron chelators, phenanthroline and deferoxamine, and a potent antioxidant, N,N'-diphenyl-p-phenylenediamine, suggesting that the H/R-induced cell injury is not attributed to a generation of reactive oxygen species. Morphological studies showed that H/R-induced structural changes including cell necrosis were significantly prevented by indomethacin. These results suggest that inhibitors of cyclooxygenase and lipoxygenase pathways exert a direct protective effect against the H/R-induced cell injury in renal tubules. Whether these effects are mediated by alterations of AA metabolic pathways is not certain.

Clinical and neuropsychological profiles of obsessive-compulsive schizophrenia: a pilot study.

This pilot study compared characteristics of obsessive-compulsive (OC) schizophrenic patients and a matched non-OC schizophrenic control group. The OC-schizophrenic group required more intensive clinical interventions and had a poorer clinical course, lower levels of functioning, and longer periods of hospitalization. They showed greater negative symptoms and more impaired executive functioning. These findings suggest OC-schizophrenic patients may have an atypical set of clinical and neuropsychiatric characteristics, perhaps constituting a subgroup within the schizophrenia spectrum. Pathophysiology and possible treatment implications require further study.

Phylogenetic relationships among Acanthamoeba spp. based on PCR-RFLP analyses of mitochondrial small subunit rRNA gene.

We investigated the value of mitochondrial small subunit rRNA gene (mt SSU rDNA) PCR-RFLP as a taxonomic tool for Acanthamoeba isolates with close inter-relationships. Twenty-five isolates representing 20 species were included in the analysis. As in nuclear 18S rDNA analysis, two type strains (A. astronyxis and A. tubiashi) of morphological group 1 diverged earliest from the other strains, but the divergence between them was less than in 18S riboprinting. Acanthamoeba griffini of morphological group 2 branched between pathogenic (A. culbertsoni A-1 and A. healyi OC-3A) and nonpathogenic (A. palestinensis Reich, A. pustulosa GE-3a, A. royreba Oak Ridge, and A lenticulata PD2S) strains of morphological group 3. Among the remaining isolates of morphological group 2, the Chang strain had the identical mitochondrial riboprints as the type strain of A. hatchetti. AA2 and AA1, the type strains of A. divionensis and A. paradivionensis, respectively, had the identical riboprints as A. quina Vil3 and A. castellanii Ma. Although the branching orders of A. castellanii Neff, A. polyphaga P23, A. triangularis SH621, and A. lugdunensis L3a were different from those in 18S riboprinting analysis, the results obtained from this study generally coincided well with those from 18S riboprinting. Mitochondrial riboprinting may have an advantage over nuclear 18S rDNA riboprinting because the mt SSU rDNAs do not seem to have introns that are found in the 18S genes of Acanthamoeba and that distort phylogenetic analyses.

Generation and chromosome mapping of expressed sequence tags (ESTs) from a human infant thymus.

In an effort to identify novel genes that are expressed differentially in an infant thymus, we constructed an oligo-d(T) primed cDNA library from a human infant thymus followed by single-run partial sequencing to generate expressed sequence tags (ESTs). Characterization of more than 1400 sequences enabled us to convert human thymus transcripts into 1223 useful ESTs. These ESTs consisted of 613 (50.1%) showing homology to known human genes, 51 (4.2%) matching to genes from other species, 289 (23.6%) matching ESTs of unknown functions, and 182 (14.9%) being novel transcripts. The expression profile of an infant thymus features a high number of genes related to cell division-DNA synthesis and gene-protein expression, indicating the active growth stage of an infant thymus. To identify the chromosomal localization of 43 thymus ESTs, PCR-based mapping was performed using a human-rodent somatic cell hybrid or radiation hybrid mapping panel. The results indicated that several novel genes were determined to be located in the vicinity of previously mapped disease loci; histidinemia loci, plasminogen Tochigi disease loci, Ehlers-Danlos syndrome, hypertriglyceridemia, thyroid resistance locus, ocular albinism, galactosemia, porphyria variegata, Charcot-Marie-tooth disease, FEOM (fibrosis of extraocular muscles), Prader-Willi syndrome.

Subgenus classification of Acanthamoeba by riboprinting.

Subgenus classification of Acanthamoeba remains uncertain. Twenty-three reference strains of Acanthamoeba including 18 (neo)type-strains were subjected for classification at the subgenus level by riboprinting. PCR/RFLP analysis of 18S rRNA gene (rDNA). On the dendrogram reconstructed on the basis of riboprint analyses, two type-strains (A. astronyxis and A. tubiashi) of morphological group 1 diverged early from the other strains and were quite distinct from each other. Four type-strains of morphological group 3, A. culbertsoni, A. palestinensis, A. healyi were considered taxonomically valid, but A. pustulosa was regarded as an invalid synonym of A. palestinensis. Strains of morphological group 2 were classified into 6 subgroups. Among them, A. griffini which has an intron in its 18S rDNA was the most divergent from the remaining strains. Acanthamoeba castellanii Castellani, A. quina Vil3, A. lugdunensis L3a, A. polyphaga Jones, A. triangularis SH621, and A. castellanii Ma strains belonged to a subgroup, A. castellanii complex. However, A. quina and A. lugdunensis were regarded as synonyms of A. castellanii. The Chang strain could be regarded as A. hatchetti. Acanthamoeba mauritaniensis, A. divionensis, A. paradivionensis could be considered as synonyms of A. rhysodes. Neff strain was regarded as A. polyphaga rather than as A. castellanii. It is likely that riboprinting can be applied for rapid identification of Acanthamoeba isolated from the clinical specimens and environments.

[Bacterial endosymbiosis within the cytoplasm of Acanthamoeba lugdunensis isolated from a contact lens storage case].

Transmission electron microscopy of an Acanthamoeba isolate (KA/L5) from a contact lens case revealed bacterial endosymbionts within cytoplasm of the amoebae. The Acanthamoeba isolate belonged to the morphological group II. Based on the polymerase chain reaction (PCR)-restriction fragment length polymorphism (RFLP) of 18S ribosomal RNA coding DNA (rDNA), the isolate was identified as A. lugdunensis. Strain typing by isoenzyme analysis using isoelectric focusing (IEF) and mitochondrial (Mt) DNA RFLP revealed that the isolate was closely related with KA/L1, the most predominant type of isolates from contact lens storage cases, KA/E2, a clinical isolate, KA/W4, previously reported to host endosymbionts, and L3a strains of A. lugdunensis. The endosymbionts were similar to those of KA/W4 in aspects that they were randomly distributed in both trophozoites and cysts, and were rod-shaped bacteria measuring approximately 1.38 x 0.50 microns. But the number of endosymbionts per amoeba was significantly lower than that of KA/W4. They were neither limited by phagosomal membranes nor included in lacunaelike structure.

Close relatedness of Acanthamoeba pustulosa with Acanthamoeba palestinensis based on isoenzyme profiles and rDNA PCR-RFLP patterns.

The taxonomic validity of morphological group III Acanthamoeba spp. is uncertain. In the present study, six type strains of group III Acanthamoeba spp., A. culbertsoni, A. healyi, A. pustulosa, A. palestinensis, A. royreba and A. lenticulata were subjected for the evaluation of their taxonomic validity by comparison of the isoenzyme patterns by isoelectic focusing on polyacrylamide gels, mitochondrial DNA (Mt DNA) restriction fragment length polymorphism (RFLP), and small subunit ribosomal DNA (ssu rDNA) PCR-RFLP patterns. The Mt DNA RFLP patterns were heterogeneous between the species. The type strains of A. palestinensis and A. pustulosa showed almost identical patterns of isoenzymes and rDNA PCR RFLP with an estimated sequence divergence of 2.6%. The other species showed heterogeneous patterns of isoenzymes and rDNA PCR-RFLP. It is likely that A. pustulosa is closely related with A. palestinensis and that the former may be regarded as a junior synonym of the latter.

Effect of high-velocity missile injury on plasma cortisol concentration in dogs.

Plasma cortisol concentrations were measured in nine dogs after high-velocity missile injury induced by spherical steel bullets. All nine dogs sustained soft-tissue wounds in the thighs without damage to large vessels, femur, or nerves. When the dogs were considered as one group the mean plasma cortisol concentration increased promptly 10 min after injury (p less than 0.05) and reached its peak at 1 hour and then decreased. The mean concentration at 6 hours after injury was still higher than that before injury (p less than 0.05). Even though the severities of the injuries varied rather much there was a significant difference (p less than 0.01) between the plasma cortisol concentrations at 1 hour of the two groups into which the dogs were divided according to the severity of their injuries. The changes of the plasma cortisol concentrations may be parallel with the extent of the injuries and there was a positive correlation with the dimensions of the entrance wounds.

Misalignment characteristics of resonators formed by 90 degrees cone and mirror.

The stability condition of a resonator formed by a 90 degrees cone and mirror has been derived using ray tracing techniques. The result showed that this type of resonator is relatively insensitive to mirror misalignment. From this basis, the mirror misalignment tolerance was studied experimentally. Output energy and transverse mode characteristics vs. misalignment were measured, and the results show that this type of resonator does possess certain advantages over the two-mirror resonator.