Thrombocytosis in preterm infants: a possible involvement of thrombopoietin receptor gene expression

Transient thrombocytosis is commonly observed in preterm infants after birth, but its physiological mechanism is still unknown. To understand the mechanism of the transient thrombocytosis in preterm infants we firstly evaluated a correlation between platelet counts and thrombopoietin (TPO) levels in preterm infants and next c-mpl mRNA levels on platelets in healthy preterm infants longitudinally during a half-year of life. The mean platelet counts in 45 very low birth weight infants (mean gestational age 27.4±1.8 weeks, mean birth weight 1047±249 g) was 230±71×10⁹/l just after birth and thereafter gradually increased to 579±178×10⁹/l by 5 weeks of age. The platelet counts continued this level for about next 8 weeks. Serum TPO levels soon after birth and at 1 month of age were significantly higher than those at the age of 2–6 months. There was a significant negative correlation between platelet counts and serum TPO values. The c-mpl expression levels on platelets at birth and at 1 month of age tended to be lower than those on platelets from adults, and the c-mpl levels gradually increased through 6 months of age, although they were still lower than those of adults. Our results suggest that low expression of TPO receptor on platelets until 1 month after birth cause a decreased TPO clearance and keep a high level of free TPO in blood, thereby promoting platelet production from megakaryocytes or their progenitors in bone marrow, resulting in the subsequent thrombocytosis in preterm infants.     

Effect of iron concentrations on the DNA-degradation reaction by bleomycin

DNA-degradation reaction by bleomycin was conducted with form I of SV40 DNA as the substrate under "iron-limited conditions" and "iron-sufficient conditions". For "iron-limited conditions", the iron ions in reaction mixtures were derived from contaminant iron in the bleomycin preparation, the molar ratio of bleomycin/iron being 1/0.05. For "iron-sufficient conditions", Fe(II) was added to reaction mixtures to attain the molar ratio of bleomycin/iron at 1/1 to 1/29. DNA-degradation reaction by Fe(II) without bleomycin, or "Fe(II) alone", was also run for comparison. In any case, the reaction was allowed to proceed at such low rates that other products than form II and form III, due to further fragmentation, were negligible. The mass of DNA in each form was quantitatively determined by spectrofluorometry after agarose gel electrophoresis and staining with ethidium bromide. "Iron-limited conditions" and "iron-sufficient conditions" showed similar reaction characteristics as follows. As form I decreased with incubation time, form II increased faster than form III, hit a plateau (ca. 65% of total DNA) and decreased gradually thereafter. Form III kept increasing throughout the incubation. The reaction was dependent on incubation time and on doses of both bleomycin and Fe(II) but rather independent of temperature. The reaction was inhibited by acidic pH, Tiron (a specific chelator of iron) and Cu(II) but not EDTA. Octanucleotides with specific base sequence inhibited the reaction. DNA-degradation reaction by "Fe(II) alone" showed different characteristics as follows. The reaction proceeded rapidly at first, but ceased within 2 minutes. The extent of reaction was dependent on dose of Fe(II). The reaction product was form II accompanied by little amount of form III. The reaction was highly dependent on temperature, inhibited by EDTA, and not inhibited by Cu(II) and acidic pH. Octanucleotides, irrespective of their base sequences, inhibited the reaction.     

Habitual Dietary Intake Affects the Altered Pattern of Gut Microbiome by Acarbose in Patients with Type 2 Diabetes

The aim of this research was to reveal the characteristics of gut microbiome altered by acarbose intervention in Japanese patients with type 2 diabetes (T2D) and its possible association with habitual dietary intake. Eighteen patients with T2D were administered acarbose for four weeks. The abundances of two major phyla, namely Actinobacteria and Bacteroidetes, were reciprocally changed accompanied by the acarbose intervention. There were also significant changes in the abundances of ten genera, including the greater abundance of Bifidobacterium, Eubacterium, and Lactobacillus and the lower abundance of Bacteroides in the group after the intervention than that before the intervention. Hierarchical clustering of habitual dietary intake was performed based on the pattern of changes in the gut microbiota and were classified into distinct three clusters. Cluster I consisted of sucrose, cluster II mainly included fat intake, and cluster III mainly included carbohydrate intake. Moreover, the amount of change in Faecalibacterium was positively correlated with the intake of rice, but negatively correlated with the intake of bread. The intake of potato was negatively correlated with the amount of change in Akkermansia and Subdoligranulum. Acarbose altered the composition of gut microbiome in Japanese patients with T2D, which might be linked to the habitual dietary intake.     

Comparison of Single and Dual Monitoring during Carotid Endarterectomy

We compared the rate of selective shunt and pattern of monitoring change between single and dual monitoring in patients undergoing carotid endarterectomy (CEA). A total of 121 patients underwent 128 consecutive CEA procedures. Excluding five procedures using internal shunts in a premeditated manner, we classified patients according to the monitoring: Group A (n = 72), patients with single somatosensory evoked potential (SSEP) monitoring; and Group B (n = 51), patients with dual SSEP and motor evoked potential (MEP). Among the 123 CEAs, an internal shunt was inserted in 12 procedures (9.8%) due to significant changes in monitoring (Group A 5.6%, Group B 15.7%, p = 0.07). The rate of shunt use was significantly higher in patients with the absence of contralateral proximal anterior cerebral artery (A1) on magnetic resonance angiography (MRA) than in patients with other types of MRA (p <0.001). Significant monitor changes were seen in 16 (12.5%) in both groups. In four of nine patients in Group B, SSEP and MEP changes were synchronized, and in the remaining five patients, a time lag was evident between SSEP and MEP changes. In conclusion, the rate of internal shunt use tended to be more frequent in patients with dual monitoring than in patients with single SSEP monitoring, but the difference was not significant. Contralateral A1 absence may predict the need for a shunt and care should be taken to monitor changes throughout the entire CEA procedure. Use of dual monitoring can capture ischemic changes due to the complementary relationship, and may reduce the rate of false-negative monitor changes during CEA.     

Nitrogen-containing bisphosphonates and lipopolysaccharide mutually augment inflammation via adenosine triphosphate (ATP)-mediated and interleukin 1β (IL-1β)-mediated production of neutrophil extracellular traps (NETs)

Among the bisphosphonates (BPs), nitrogen-containing BPs (N-BPs) have much stronger anti–bone-resorptive actions than non-N–BPs. However, N-BPs have various side effects such as acute influenza-like reactions after their initial administration and osteonecrosis of the jawbones after repeated administration. The mechanisms underlying such effects remain unclear. To overcome these problems, it is important to profile the inflammatory nature of N-BPs. Here, we analyzed the inflammatory reactions induced in mouse ear pinnae by the N-BPs alendronate (Ale) and zoledronate (Zol). We found the following: (i) Ale and Zol each induced two phases of inflammation (early weak and late strong ear swelling); (ii) both phases were augmented by lipopolysaccharides (LPSs; cell-surface constituent of gram-negative bacteria, including oral bacteria), but prevented by inhibitors of the phosphate transporters of solute carrier 20/34 (SLC20/SLC34); (iii) macrophages and neutrophils were involved in both phases of Ale+LPS–induced ear-swelling; (iv) Ale increased or tended to increase various cytokines, and LPS augmented these effects, especially that on interleukin 1β (IL-1β); (v) adenosine triphosphate (ATP) was involved in both phases, and Ale alone or Ale+LPS increased ATP in ear pinnae; (vi) the augmented late-phase swelling induced by Ale+LPS depended on both IL-1 and neutrophil extracellular traps (NETs; neutrophil-derived net-like complexes); (vii) neutrophils, together with macrophages and dendritic cells, also functioned as IL-1β–producing cells, and upon stimulation with IL-1β, neutrophils produced NETs; (viii) stimulation of the purinergic 2X7 (P2X7) receptors by ATP induced IL-1β in ear pinnae; (ix) NET formation by Ale+LPS was confirmed in gingiva, too. These results suggest that (i) N-BPs induce both early-phase and late-phase inflammation via ATP-production and P2X7 receptor stimulation; (ii) N-BPs and LPS induce mutually augmenting responses both early and late phases via ATP-mediated IL-1β production by neutrophils, macrophages, and/or dendritic cells; and (iii) NET production by IL-1β–stimulated neutrophils may mediate the late phase, leading to prolonged inflammation. These results are discussed in relation to the side effects seen in patients treated with N-BPs. © 2021 American Society for Bone and Mineral Research (ASBMR).     

Decrease of lymphokine (interleukin-2)-activated killer activity in peripheral blood after administration of natural interferon-gamma

Interferon-gamma (IFN-gamma) acts on a large array of different types of cell and has potent immunomodulatory activities besides cytotoxic effects on tumors. In a phase I study, some immunologic parameters of blood mononuclear cells from healthy volunteers who received intramuscular injections of natural human IFN-gamma were analyzed. The percentage of Leu-11a positive cells, natural killer (NK) activity, lymphokine (interleukin-2)-activated killer (LAK) activity and monokine production were measured either in blood mononuclear cells or in purified samples of lymphocytes or monocytes of the donors before and 24 h after IFN-gamma injection. After IFN-gamma injection, the percentage of Leu-11a positive cells and the LAK activity in the blood were significantly reduced, but NK activity and monokine production remained unchanged. These findings suggest that in vivo IFN-gamma acts directly or indirectly on Leu-11a positive cells and reduces LAK activity by changing the recruitment of LAK precursors in the blood.     

Prevalence of second generation antibody to hepatitis C virus among voluntary blood donors in Osaka,Japan

To clarify the demographic characteristics of the prevalence of hepatitis C virus (HCV) infection in Osaka, Japan, where hepatocellular carcinoma is common, we investigated the screening data of antibody to HCV (anti-HCV, DAINABOTHCVPHA, second generation assay) in 197,600 voluntary blood donors residing in Osaka. The study found that age-standardized prevalence of anti-HCV was significantly higher than that of HBsAg (2.25cf 0.86 percent among males,P<0.001; 2.17cf 0.55 percent among females,P<0.001. It was much higher in the blood donors aged 55–64 years than in those aged 16–54 years (8.49cf 1.32 percent among males,P<10^–5; 7.26cf 1.42 percent among females,P<10^–5). The prevalence of anti-HCV among males was significantly higher than that of females in the younger (25–34 years) generations (1.02 to 1.49 percentcf 0.71 to 1.13 percent,P<0.05). A similar tendency was observed in the prevalence of high-titer (2¹²) anti-HCV. The number of coinfection (both HBsAg and anti-HCV seropositive) was very small, and it was not statistically different from the expected number.