Adverse reactions and effects on renal function of COVID-19 vaccines in patients with IgA nephropathy.

BACKGROUND: Although vaccination has been reported to reduce the morbidity and severity of COVID-19 infection in patients with kidney disease, gross hematuria is frequently reported following vaccination in patients with IgA nephropathy. We investigated the frequency of gross hematuria following COVID-19 vaccination and its effect on renal function in IgA nephropathy patients. METHODS: Adverse reactions after two or more COVID-19 vaccine doses were investigated in 295 IgA nephropathy patients attending Osaka Cty general hospital from September 2021 to November 2022. We compared differences in background characteristics and other adverse reactions between groups with and without gross hematuria after vaccination, and examined changes in renal function and proteinuria. RESULTS: Twenty-eight patients (9.5%) had gross hematuria. The median age of patients with and without gross hematuria was 44 (29-48) and 49 (42-61) years, respectively, indicating a significant difference. The percentage of patients with microscopic hematuria before vaccination differed significantly between those with (65.2%) and without (32%) gross hematuria. Adverse reactions, such as fever, chills, headache and arthralgia, were more frequent in patients with gross hematuria. There was no difference in renal functional decline after approximately 1 year between patients with and without gross hematuria. We also found no significant changes in estimated glomerular filtration rate or proteinuria before and after vaccination in the gross hematuria group. However, some patients clearly had worsening of renal function. CONCLUSIONS: While COVID-19 vaccination is beneficial, care is required since it might adversely affect renal function in some patients.

Effects of molidustat, a hypoxia-inducible factor prolyl hydroxylase inhibitor, on sodium dynamics in hypertensive subtotally nephrectomized rats.

Hypoxia-inducible factor prolyl hydroxylase (HIF-PHD) inhibitors were developed for treatment of renal anemia. Patients applicable for HIF-PHD inhibitor treatment experience complications such as chronic kidney disease, whereby water and electrolyte homeostasis is disrupted. The effects of hypoxia-inducible factor stabilization on salt accumulation in the setting of reduced renal function remain unclear. In the present study, we investigated the effect of a HIF-PHD inhibitor, molidustat, on salt distribution and excretion in rats with subtotal nephrectomy-induced chronic kidney disease. Male Wistar rats were subjected to 5/6 nephrectomy. After confirming blood pressure elevation (>150 mmHg, at 4 weeks after surgery), rats were treated with molidustat. After 1 week of treatment, molidustat did not significantly improve blood cell volume or blood pressure. Distribution of sodium, potassium, and water in skin, carcass, and bone samples was not affected by molidustat. Furthermore, molidustat had no significant effect on urinary sodium excretion or concentration in response to acute oral salt loading (1 g/kg). In conclusion, molidustat did not affect distribution or excretion of salt in rats subjected to a model of nephron loss.

Efficient conversion to Cypridina luciferin from Cypridina luciferyl sulfate, coupled with enzymatic sulfation of acetic acid.

In Cypridina (Vargula) hilgendorfii, Cypridina luciferin is converted from Cypridina luciferyl sulfate by a sulfotransferase with adenosine 3', 5'-diphosphate (PAP), and is used for the luminescence reaction of Cypridina luciferase. We found that the luminescence activity of crude extracts of C. hilgendorfii was significantly stimulated by the addition of acetic acid. This stimulation may be explained by an efficient supply of PAP from 3'-phosphoadenosine 5'-phosphosulfate (PAPS) catalyzed by a sulfotransferase. Thus, acetic acid acts as a sulfate acceptor from PAPS, followed by forming acetyl sulfate and PAP. The structure of acetyl sulfate was identified using mass spectrometry and it spontaneously decomposed to acetic acid and free sulfate ion in aqueous solutions. This enzymatic conversion from Cypridina luciferyl sulfate to Cypridina luciferin could be coupled with acetic acid and PAPS by a sulfotransferase.

Correction to: A nationwide survey on clinical practice patterns and bleeding complications of percutaneous native kidney biopsy in Japan.

In the original publication, some errors have been found in the alignment of Table 9. The corrected table is given below.

A nationwide survey on clinical practice patterns and bleeding complications of percutaneous native kidney biopsy in Japan.

BACKGROUND: Practice patterns and bleeding complications of percutaneous native kidney biopsy (PNKB) have not recently been investigated and the Japanese Society of Nephrology performed a nationwide questionnaire survey in 2018. METHODS: The survey consisted of nine sections about PNKB: (1) general indications; (2) indications for high-risk patients; (3) informed consent; (4) pre-biopsy evaluation; (5) procedures; (6) sedation; (7) post-biopsy hemostasis, bed rest, and examinations; (8) bleeding complications; and (9) specimen processing. A supplementary survey examined bleeding requiring transcatheter arterial embolization (TAE). RESULTS: Overall, 220 directors of facilities (nephrology facility [NF], 168; pediatric nephrology facility [PF], 52) completed the survey. Indications, procedures, and monitoring protocols varied across facilities. Median lengths of hospital stay were 5 days in NFs and 6 days in PFs. Gauge 14, 16, 18 needles were used in 5%, 56%, 33% in NFs and 0%, 63%, 64% in PFs. Mean limits of needle passes were 5 in NFs and 4 in PFs. The bed rest period was 16-24 h in 60% of NFs and 65% of PFs. Based on 17,342 PNKBs, incidence rates of macroscopic hematuria, erythrocyte transfusion, and TAE were 3.1% (NF, 2.8%; PF, 6.2%), 0.7% (NF, 0.8%; PF, 0%), and 0.2% (NF, 0.2%; PF, 0.06%), respectively. Forty-six percent of facilities processed specimens all for light microscopy, immunofluorescence, and electron microscopy, and 21% processed for light microscopy only. Timing of bleeding requiring TAE varied among PNKB cases. CONCLUSION: Wide variations in practice patterns of PNKB existed among facilities, while PNKBs were performed as safely as previously reported.

Diversity of Bradyrhizobium in Non-Leguminous Sorghum Plants: B. ottawaense Isolates Unique in Genes for N2O Reductase and Lack of the Type VI Secretion System.

Diverse members of Bradyrhizobium diazoefficiens, B. japonicum, and B. ottawaense were isolated from the roots of field-grown sorghum plants in Fukushima, and classified into "Rhizobia" with nodulated soybeans, "Free-living diazotrophs", and "Non-diazotrophs" by nitrogen fixation and nodulation assays. Genome analyses revealed that B. ottawaense members possessed genes for N2O reduction, but lacked those for the Type VI secretion system (T6SS). T6SS is a new bacterial weapon against microbial competitors. Since T6SS-possessing B. diazoefficiens and B. japonicum have mainly been isolated from soybean nodules in Japan, T6SS-lacking B. ottawaense members may be a cryptic lineage of soybean bradyrhizobia in Japan.

The angiotensin II receptor-neprilysin inhibitor LCZ696 attenuates the progression of proteinuria in type 2 diabetic rats.

We examined the effects of the angiotensin receptor-neprilysin inhibitor LCZ696 on overt proteinuria and renal injury in type 2 diabetic Otsuka-Long- Evans-Tokushima-Fatty (OLETF) rats. Aged OLETF rats were also treated with either valsartan or valsartan plus hydralazine for comparison. LCZ696 caused greater attenuation of the progression of proteinuria than either valsartan alone or valsartan combined with hydralazine. Reduced glomerular injury and tubulointerstitial fibrosis were also observed in LCZ696-treated rats. Moreover, LCZ696 prevented increases in blood urea nitrogen (BUN) and creatinine levels. These data suggest that LCZ696 elicits a reno-protective effect against type 2 diabetes with overt proteinuria.

Renal sympathetic nerve activity regulates cardiovascular energy expenditure in rats fed high salt.

We recently reported that a 4% high-salt diet + saline for drinking (HS + saline) leads to a catabolic state, reduced heart rate, and suppression of cardiovascular energy expenditure in mice. We suggested that HS + saline reduces heart rate via the suppression of the sympathetic nervous system to compensate for the high salt intake-induced catabolic state. To test this hypothesis, we directly measured renal sympathetic nerve activity (RSNA) in conscious Sprague-Dawley (SD) rats using a radiotelemetry system. We confirmed that HS + saline induced a catabolic state. HS + saline decreased heart rate, while also reducing RSNA in SD rats. In contrast, Dahl salt-sensitive (DSS) rats exhibited no change in heart rate and increased RSNA during high salt intake. Renal denervation significantly decreased heart rate and attenuated the catabolic state independent of blood pressure in DSS rats fed HS + saline, suggesting that salt-sensitive animals were unable to decrease cardiovascular energy consumption due to abnormal renal sympathetic nerve activation during high salt intake. These findings support the hypothesis that RSNA mediates heart rate during high salt intake in SD rats. However, the insensitivity of heart rate and enhanced RSNA observed in DSS rats may be additional critical diagnostic factors for salt-sensitive hypertension. Renal denervation may benefit salt-sensitive hypertension by reducing its effects on catabolism and cardiovascular energy expenditure.

Failure to confirm a sodium-glucose cotransporter 2 inhibitor-induced hematopoietic effect in non-diabetic rats with renal anemia.

AIMS/INTRODUCTION: Clinical studies have shown that treatment with inhibitors of sodium-glucose cotransporter 2 (SGLT2) significantly increases the hematocrit in patients with type 2 diabetes. To investigate whether SGLT2 inhibitors directly promote erythropoietin production independently on blood glucose reduction, the hematopoietic effect of the specific SGLT2 inhibitor, luseogliflozin, was examined in non-diabetic rats with renal anemia. MATERIALS AND METHODS: Renal anemia was induced by treatment with adenine (200 or 600 mg/kg/day, orally for 10 days) in non-diabetic Wistar-Kyoto or Wistar rats, respectively. Luseogliflozin (10 mg/kg bodyweight) or vehicle (0.5% carboxymethyl cellulose) was then administered for 6 weeks. The hematocrit and the hemoglobin (Hb), blood urea nitrogen, plasma creatinine, and plasma erythropoietin levels were monitored. RESULTS: Treatment with adenine decreased the hematocrit and the Hb level, which were associated with increases in the blood urea nitrogen and plasma creatinine levels. In Wistar-Kyoto rats treated with 200 mg/kg/day adenine, administration of luseogliflozin induced glycosuria, but did not change the blood urea nitrogen, plasma creatinine levels, hematocrit, Hb or plasma erythropoietin levels. Similarly, luseogliflozin treatment failed to change the hematocrit or the Hb levels in Wistar rats with renal anemia induced by 600 mg/kg/day of adenine. Plasma erythropoietin concentrations were also not different between luseogliflozin- and vehicle-treated rats. Similarly, in human erythropoietin-producing cells derived from pluripotent stem cells, luseogliflozin treatment did not change the erythropoietin level in the medium. CONCLUSIONS: These data suggest that SGLT2 inhibitor fails to exert hematopoietic effects in non-diabetic conditions.

Identification of Nitrogen-Fixing Bradyrhizobium Associated With Roots of Field-Grown Sorghum by Metagenome and Proteome Analyses.

Sorghum (Sorghum bicolor) is cultivated worldwide for food, bioethanol, and fodder production. Although nitrogen fixation in sorghum has been studied since the 1970s, N2-fixing bacteria have not been widely examined in field-grown sorghum plants because the identification of functional diazotrophs depends on the culture method used. The aim of this study was to identify functional N2-fixing bacteria associated with field-grown sorghum by using "omics" approaches. Four lines of sorghum (KM1, KM2, KM4, and KM5) were grown in a field in Fukushima, Japan. The nitrogen-fixing activities of the roots, leaves, and stems were evaluated by acetylene reduction and 15N2-feeding assays. The highest nitrogen-fixing activities were detected in the roots of lines KM1 and KM2 at the late growth stage. Bacterial cells extracted from KM1 and KM2 roots were analyzed by metagenome, proteome, and isolation approaches and their DNA was isolated and sequenced. Nitrogenase structural gene sequences in the metagenome sequences were retrieved using two nitrogenase databases. Most sequences were assigned to nifHDK of Bradyrhizobium species, including non-nodulating Bradyrhizobium sp. S23321 and photosynthetic B. oligotrophicum S58T. Amplicon sequence and metagenome analysis revealed a relatively higher abundance (2.9-3.6%) of Bradyrhizobium in the roots. Proteome analysis indicated that three NifHDK proteins of Bradyrhizobium species were consistently detected across sample replicates. By using oligotrophic media, we purified eight bradyrhizobial isolates. Among them, two bradyrhizobial isolates possessed 16S rRNA and nif genes similar to those in S23321 and S58T which were predicted as functional diazotrophs by omics approaches. Both free-living cells of the isolates expressed N2-fixing activity in a semi-solid medium according to an acetylene reduction assay. These results suggest that major functional N2-fixing bacteria in sorghum roots are unique bradyrhizobia that resemble photosynthetic B. oligotrophicum S58T and non-nodulating Bradyrhizobium sp. S23321. Based on our findings, we discuss the N2-fixing activity level of sorghum plants, phylogenetic and genomic comparison with diazotrophic bacteria in other crops, and Bradyrhizobium diversity in N2 fixation and nodulation.

Effect of a SGLT2 inhibitor on the systemic and intrarenal renin-angiotensin system in subtotally nephrectomized rats.

We aimed to examine the effects of a sodium glucose co-transporter 2 (SGLT2) inhibitor on systemic and intrarenal renin-angiotensin system (RAS) in subtotally nephrectomized non-diabetic rats, a model of chronic kidney disease (CKD). Oral administration of the selective SGLT2 inhibitor, TA-1887 (10 mg/kg/day), for 10 weeks induced glycosuria. However, plasma renin activity, plasma angiotensinogen levels, kidney angiotensin II contents and renal injury were not significantly affected by TA-1887. These data indicate that chronic treatment with an SGLT2 inhibitor does not activate the systemic and intrarenal RAS in subjects with non-diabetic CKD.

Investigation of morphological changes for the discrimination of nucleated red blood cells and other leukocytes in Sysmex XN hematology analyzer scattergrams using transmission electron microscopy.

BACKGROUND: The WNR channel of the XN-Series automated hematology analyzer (Sysmex) counts white blood cells (WBCs) and simultaneously performs a differential counting of basophils and nucleated red blood cells (NRBCs). The detection process involves exposing the cells to WNR-specific reagents containing an acidic detergent and a fluorescent dye and measuring the intensity of the forward scattered light (FSC) and side fluorescence light (SFL). METHOD: We treated isolated peripheral WBCs and NRBCs with specific reagents and assessed the morphological changes in NRBCs and each leukocyte type using transmission electron microscopy (TEM). RESULTS: The results from a flow cytometer (FCM) showed that, after exposure to the reagents, basophils appeared on the highest FSC and SFL areas compared to other leukocytes on the WNR scattergram. Owing to the hemolysis of reticulocytes and erythrocytes, NRBCs that survived the reagent treatment could be distinguished by their lower intensity than those of the other leukocytes on the WNR scattergram. We investigated the significance of the relationship between the TEM and FCM results after the reagent treatment. CONCLUSION: We confirmed that the WNR channel differentiates the blood cells on the WNR scattergram based on differences in the amount of residual cytoplasm and nucleic acids.

[Measurement of Liver Fibrosis Marker Targeting Sugar Chain Marker].

The degree of liver fibrosis progression is an important factor in hepatocarcinogenesis, and monitoring liver fibrosis is important for predicting and preventing hepatocellular carcinoma. It is proportional to the appearance of a new hepatitis C therapy, or the expectation of liver fibrosis therapy, and liver fibrosis research is attracting attention. Although the Gold Standard for the diagnosis of liver fibrosis is liver biopsy, various problems, such as in the difficulty of invasive and frequent measurement, exist. The present non-invasive examination methods for the assessment of liver fibrosis also have a problem in the fields of organ specificity and diagnostic performance. Using a fully automated immunoassay system "HISCL", an assay system based on the lectin bound sugar reaction which is not an antigen-bound antibody reaction was developed. Measurements using the fully automated immunoassay system "HISCL" series and HISCL M2BPGi assay kit facilitated rapid assay (17 minutes) with a small sample volume (10 µL). Serum M2BPGi values can be used in various ways, such as for assessment of the risk and treatment associated with hepatocellular carcinoma, reflecting the liver fibrosis stage. Furthermore, many studies are currently in progress. The development of a new assay system for the detection of a cancer production sugar chain marker is expected in the future owing to the advent of a lectin-bound sugar chain reaction system.

Accuracy of a New Platelet Count System (PLT-F) Depends on the Staining Property of Its Reagents.

BACKGROUND: Platelet count is essential for the diagnosis and management of hemostasis abnormalities. Although existing platelet count methods installed in common hematology analyzers can correctly count platelets in normal blood samples, they tend to miscount platelets in some abnormal samples. The newly developed PLT-F channel in the XN-Series hematology analyzer (Sysmex) has been reported to be a reliable platelet count system, even in abnormal samples. However, how the PLT-F platelet counting system achieves such accuracy has not been described in scientific articles. METHODS: Isolated platelets, erythrocytes, and fragmented erythrocytes were examined using an automated hematology analyzer. The samples were labeled by combining PLT-F reagents and anti-CD62p, CD63, Grp75, Calreticulin, CD41, or CD61 antibody, and analyzed using confocal laser scanning microscopy or flow cytometry. RESULTS: The PLT-F system correctly discriminated platelets in erythrocytes. Its reagents strongly stained some intraplatelet organelles labeled with anti-Grp75, but only faintly stained the plasma membrane of both platelets and erythrocytes. Microscopic observation and flow cytometric examination revealed that all of these strongly stained cells were also labeled with platelet-specific anti-CD41 and anti-CD61 antibodies. CONCLUSIONS: This study revealed that the staining property of the PLT-F reagents, by which platelets and fragmented erythrocytes are clearly distinguished, contributes to the platelet-counting accuracy of the PLT-F system.

Comparison of optical data from flow cytometry and microscopy of leukocytes after exposure to specific reagents.

Flow cytometry and microscopy are equally important in cell analysis. However, few reports have compared the optical data (cell size, internal complexity and fluorescent signal) from flow cytometry and microscopy. In this study, we compared the scattergram from XN-series, a flow cytometry based hematology analyzer with microscopic images of similarly treated leukocytes, and investigated the correlation between the appearance in the scattergram and cell size, internal complexity and fluorescence intensity. Healthy human peripheral blood was analyzed using the XN analyzer. For microscopic comparison, five types of leukocytes (monocytes, lymphocytes, basophils, neutrophils and eosinophils) were isolated from the peripheral blood by centrifugation and magnetic cell sorting, treated with a specific reagent and analyzed using electron microscopy, laser microscopy and confocal laser microscopy. Cell size, residual internal structures and fluorescence intensity correlated with intensity of forward-scattering, side scattering and fluorescent light. In this study, optical data from a clinically used hematology analyzer was clarified using microscopic images.