Comparison of Muscle Color and Total Selenium Concentrations Between Spotted Mackerel Scomber australasicus and Pacific Mackerel S. japonicus.

Selenoneine is a selenium-containing imidazole compound in the blood and tissues of tuna and other marine fish that has strong free-radical scavenging activity. This compound may have antioxidant functions, i.e., preventing metmyoglobin formation in fish muscle, which affects meat quality. This study examined the relationship between meat color and total selenium concentration in the muscle of two Scomber species, spotted mackerel (Scomber australasicus) and Pacific mackerel (S. japonicus), to assess the role of selenium as an antioxidant preventing meat discoloration. The color of chilled and frozen-thawed muscle was compared between spotted mackerel and Pacific mackerel. The a* values, indicating the red-green component of color, of the white and red muscle of spotted mackerel were higher than those of Pacific mackerel (p < 0.05). We also analyzed the blood selenium concentration of Pacific mackerel according to the L* value and protein concentration in the blood during spawning migration in June. The blood selenium concentration was negatively correlated with the L* value (r = - 0.46) and blood protein concentration (r = - 0.56). The blood selenium concentration in summer was related to the brightness of the muscle surface and blood protein concentration, suggesting that it is responsible for deterioration of meat quality.These findings suggest that antioxidant properties of selenium prevent the mackerel muscle discoloration that can occur during chilled and frozen storage.

A case of anti-melanoma differentiation-associated gene 5 antibody-positive dermatomyositis-associated rapidly progressive interstitial lung diseases developed after administration of COVID-19 vaccine and subsequent pneumococcal vaccine.

Five cases of anti-melanoma differentiation-associated gene 5 antibody-positive dermatomyositis-associated rapidly progressive interstitial lung diseases (anti-MDA5-positive DM-RPILD) following COVID-19 vaccination have been reported previously. We present the first case of the disease that developed following the sequence of COVID-19 infection, COVID-19 vaccination, and 23-valent pneumococcal polysaccharide vaccine (PPSV23) administration. A 75-year-old-Japanese man received the third dose of Pfizer COVID-19 vaccine 4 weeks after he had a mild COVID-19 infection. Eleven weeks after vaccination, he received PPSV23 for the first time. He developed fever, malaise, and anorexia the day after the PPSV23, rash a week later, and shortness of breath 2 weeks later. He was then admitted to a local hospital and treated with antibiotics, but his condition worsened. He was transferred to our hospital 4 weeks after the PPSV23 and was diagnosed with anti-MDA5-positive DM-RPILD. Despite intensive treatment, the patient died on the 10th hospital day.

Hepatic Cytochrome P450 Activity and Nitric Oxide Production During Multiple Ovalbumin Challenges.

BACKGROUND AND OBJECTIVES: Mast cell-mediated allergic diseases are a significant global health problem. Nitric oxide (NO) produced by acute type 1 allergies greatly suppresses hepatic cytochrome P450 (CYP) metabolism. A recent in vitro study demonstrated that repeated FcεRI-mediated activation intrinsically modulates mast cell function. We investigated the effect of ovalbumin (OVA) challenges on CYP activity and NO production under real immune responses. METHODS: After repeated sensitization with OVA once a week, serum nitrate plus nitrite (NOx) and total plasma immunoglobulin E concentrations were measured using commercially available kits. Hepatic microsomal CYP-specific activities and protein expression were determined using typical substrates and by western blot, respectively. In the liver, the levels of inducible NO synthase (iNOS), F4/80, and c-kit mRNA were determined by real-time polymerase chain reaction. Hepatic total NOS activity was measured using a colorimetric assay kit. RESULTS: When mice received multiple OVA challenges, the 11th sensitization elevated NOx concentrations in serum and suppressed the activities of five major CYPs without altering protein expression levels. After the 7th, 11th, and 15th sensitizations, F4/80-positive Kupffer cell and hepatic c-kit-dependent mast cell mRNA levels were similar to those of the control. The 7th and 11th sensitizations increased hepatic iNOS mRNA expression to 15-fold and threefold above control levels, respectively, but did not enhance the total NOS activity in the liver. CONCLUSIONS: Multiple OVA challenges, unlike acute sensitization, greatly reduced serum NOx levels. The challenge-suppressed hepatic CYP metabolism was likely related to the increased serum NOx. Serum NOx may be an endogenous marker for CYP metabolism inhibition in type 1 allergic diseases.

Biochemical and Spectroscopic Characterizations of a Hybrid Light-Harvesting Reaction Center Core Complex.

The light-harvesting 1 reaction center (LH1-RC) complex from Thermochromatium tepidum exhibits a largely red-shifted LH1 Q y absorption at 915 nm due to binding of Ca2+, resulting in an "uphill" energy transfer from LH1 to the reaction center (RC). In a recent study, we developed a heterologous expression system (strain TS2) to construct a functional hybrid LH1-RC with LH1 from Tch. tepidum and the RC from Rhodobacter sphaeroides [Nagashima, K. V. P., et al. (2017) Proc. Natl. Acad. Sci. U. S. A. 114, 10906]. Here, we present detailed characterizations of the hybrid LH1-RC from strain TS2. Effects of metal cations on the phototrophic growth of strain TS2 revealed that Ca2+ is an indispensable element for its growth, which is also true for Tch. tepidum but not for Rba. sphaeroides. The thermal stability of the TS2 LH1-RC was strongly dependent on Ca2+ in a manner similar to that of the native Tch. tepidum, but interactions between the heterologous LH1 and RC became relatively weaker in strain TS2. A Fourier transform infrared analysis demonstrated that the Ca2+-binding site of TS2 LH1 was similar but not identical to that of Tch. tepidum. Steady-state and time-resolved fluorescence measurements revealed that the uphill energy transfer rate from LH1 to the RC was related to the energy gap in an order of Rba. sphaeroides, Tch. tepidum, and strain TS2; however, the quantum yields of LH1 fluorescence did not exhibit such a correlation. On the basis of these findings, we discuss the roles of Ca2+, interactions between LH1 and the RC from different species, and the uphill energy transfer mechanisms.

Probing structure-function relationships in early events in photosynthesis using a chimeric photocomplex.

The native core light-harvesting complex (LH1) from the thermophilic purple phototrophic bacterium Thermochromatium tepidum requires Ca2+ for its thermal stability and characteristic absorption maximum at 915 nm. To explore the role of specific amino acid residues of the LH1 polypeptides in Ca-binding behavior, we constructed a genetic system for heterologously expressing the Tch. tepidum LH1 complex in an engineered Rhodobacter sphaeroides mutant strain. This system contained a chimeric pufBALM gene cluster (pufBA from Tch. tepidum and pufLM from Rba. sphaeroides) and was subsequently deployed for introducing site-directed mutations on the LH1 polypeptides. All mutant strains were capable of phototrophic (anoxic/light) growth. The heterologously expressed Tch. tepidum wild-type LH1 complex was isolated in a reaction center (RC)-associated form and displayed the characteristic absorption properties of this thermophilic phototroph. Spheroidene (the major carotenoid in Rba. sphaeroides) was incorporated into the Tch. tepidum LH1 complex in place of its native spirilloxanthins with one carotenoid molecule present per αß-subunit. The hybrid LH1-RC complexes expressed in Rba. sphaeroides were characterized using absorption, fluorescence excitation, and resonance Raman spectroscopy. Site-specific mutagenesis combined with spectroscopic measurements revealed that α-D49, ß-L46, and a deletion at position 43 of the α-polypeptide play critical roles in Ca binding in the Tch. tepidum LH1 complex; in contrast, α-N50 does not participate in Ca2+ coordination. These findings build on recent structural data obtained from a high-resolution crystallographic structure of the membrane integrated Tch. tepidum LH1-RC complex and have unambiguously identified the location of Ca2+ within this key antenna complex.

Prescription rate of medications potentially contributing to lower urinary tract symptoms and detection of adverse reactions by prescription sequence symmetry analysis.

BACKGROUND: The lower urinary tract symptoms (LUTS) increases with age and can have a significant effect on the quality of life of the patients. Elderly patients, who are often characterized by a decline in physiological functional and polypharmacy, are susceptible to adverse drug reactions to pharmacotherapy. LUTS can also be a side effect of medication. The purpose of this study was to investigate the possible association between the initiation of LUTS-causing drug therapy and the onset of LUTS. METHODS: Drug dispensing data at the individual level were retrieved from the CISA (Platform for Clinical Information Statistical Analysis: http://www.cisa.jp) database. A retrospective study was conducted by reviewing patients with LUTS who were dispensed drugs that increased the risk of LUTS between April 2011 and March 2012. Prescription sequence symmetry analysis (PSSA) was employed to investigate the associations between the dispensing of medicines of LUTS and that of LUTS-causing drugs. RESULTS: LUTS-causing drugs were frequently dispensed to patients with LUTS. The use of medications potentially contributing to LUTS was associated with polypharmacy [number of prescription drugs:12.13 ± 6.78 (user) vs. 5.67 ± 5.24 (nonuser)] but not patient age [ age: (71.38 ± 13.28 (user) vs. 70.45 ± 14.80 (nonuser)]. Significant adverse drug events were observed the use of donepezil, cyclophosphamide, antiparkinson drugs, antidepressant, diazepam, antipsychotic drugs for peptic ulcer, tiotropium bromide, and opioids. CONCLUSIONS: The use of prescription LUTS-causing drugs was correlated with polypharmacy. The adverse drug events associated with LUTS-causing drugs were highly prevalent in elderly patients. To prevent of adverse drug events in patients with LUTS, pharmacists and physicians should regularly review medication lists and reduce the prescribed medicines.

Thiocyanate hydrolase is a cobalt-containing metalloenzyme with a cysteine-sulfinic acid ligand.

Thiocyanate hydrolase (SCNase) purified from Thiobacillus thioparus THI115 hydrolyzes thiocyanate to carbonyl sulfide and ammonia. DNA sequences of the cloned genes revealed the close relation of SCNase to nitrile hydratase (NHase). The consensus sequences for coordination of the metal ion found in NHases were also conserved in the gamma subunit of SCNase. Here, we showed that the SCNase contained one cobalt atom per alphabetagamma heterotrimer. UV-vis absorption spectrum suggested that the cobalt exists as a non-corrin ion. Reduced SCNase showed an ESR signal characteristic of low-spin Co2+, which closely resembled that of the Co-type NHases. Mass spectrometry for the peptide fragment containing the metal-binding motif of the SCNase gamma subunit indicated that the cysteine residue at position 131 was post-translationally oxidized to a cysteine-sulfinic acid. From these results, we concluded that SCNases and NHases form a novel non-corrin and/or non-heme protein family having post-translationally modified cysteine ligands.

Induction of a proliferative response of T cells by a high-molecular antigen in Dermatophagoides farinae feces.

BACKGROUND: We have previously demonstrated that high-molecular mite antigen (HM1) from Dermatophagoides farinae feces is an allergen which binds to mite-allergic patients IgE. HM1 also induced a proliferative response in lymph node cells from mite-immunized mice as well as nonimmunized mice. In the present study, we demonstrated that HM1 induced T cell proliferation and investigated the HM1-stimulated T cell proliferative pathways using nonallergic human peripheral blood mononuclear cells (PMBC). METHODS: Blood samples were obtained from 10 healthy donors. Using primary culture, T cell response stimulated with HM1 was performed on purified T cells, CD19+ cell-depleted PBMC and CD11b+ cell-depleted PBMC. In addition, interleukin (IL)-5 and interferon (IFN)-gamma produced by mite-allergic and healthy donors stimulated with HM1 were estimated by enzyme immunoassay. RESULTS: T cell proliferation was detected only in CD19+ cell-depleted PBMC. When T cells were cocultured with CD11b+ cells they recovered their proliferative response to HM1. In addition, the pathway of HM1-stimulated T cell proliferation did not involve HLA class II restriction. Both activated CD11b+ cells and their conditioned media were needed to induce HM1-stimulated T cell proliferation. Furthermore, HM1 induced IFN-gamma production in both healthy and allergic donors. CONCLUSION: The high-molecular mite antigen, HM1, induced a proliferative response of T cells in healthy as well as allergic donors, without HLA class II restriction. Our results suggest that further investigation of HM1 could constitute a valuable avenue of research into complex allergic diseases.