Practical use of the central venous access port for contrast-enhanced CT: comparison with peripheral intravenous access regarding enhancement and safety

AIM

To evaluate the efficacy of using the central venous (CV) port compared with peripheral intravenous access for contrast-material injection for contrast enhancement during the portal venous phase.

MATERIALS AND METHODS

Patients were divided into three groups: CV delay, CV routine, and peripheral access (PA) groups. Patients in the CV delay group underwent injection in the arm-down position with an additional delay, while those in the CV routine and PA groups underwent injections with the routine injection protocol for portal venous phase imaging. Contrast enhancement was evaluated by measuring the mean radiodensity (Hounsfield units) values for the aortic arch, abdominal aorta, inferior vena cava, portal vein, and spleen. The peak injection pressure was recorded and compared among the three groups.

RESULTS

No complications related to power injection were observed during 119 contrast-material injections performed using the CV port device. The CV delay group showed significantly lower radiodensity values than the PA group (165.7 ± 20.1 versus 181 ± 19 HU [p<0.01] for the portal vein); however, no significant differences in mean radiodensity values were observed between the CV routine and PA groups (p>0.05). The median peak injection pressure was 73.5, 67, and 47 psi in the CV delay, CV routine, and PA groups, respectively (p<0.01).

CONCLUSION

The CV port can be used for safe contrast-material injection while maintaining contrast enhancement on portal venous phase comparable to that achieved with peripheral intravenous access.

2-thiouridine is a broad-spectrum antiviral nucleoside analogue against positive-strand RNA viruses

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections are causing significant morbidity and mortality worldwide. Furthermore, over 1 million cases of newly emerging or re-emerging viral infections, specifically dengue virus (DENV), are known to occur annually. Because no virus-specific and fully effective treatments against these or many other viruses have been approved, there is an urgent need for novel, effective therapeutic agents. Here, we identified 2-thiouridine (s2U) as a broad-spectrum antiviral ribonucleoside analogue that exhibited antiviral activity against several positive-sense single-stranded RNA (ssRNA+) viruses, such as DENV, SARS-CoV-2, and its variants of concern, including the currently circulating Omicron subvariants. s2U inhibits RNA synthesis catalyzed by viral RNA-dependent RNA polymerase, thereby reducing viral RNA replication, which improved the survival rate of mice infected with DENV2 or SARS-CoV-2 in our animal models. Our findings demonstrate that s2U is a potential broad-spectrum antiviral agent not only against DENV and SARS-CoV-2 but other ssRNA+ viruses.

Propofol infusions using a human target controlled infusion (TCI) pump in chimpanzees (Pan troglodytes)

Chimpanzees are genetically and physiologically similar to humans. Several pharmacokinetic models of propofol are available and target controlled infusion (TCI) of propofol is established in humans, but not in chimpanzees. The purpose of this study was to investigate if human pharmacokinetic models can accurately predict propofol plasma concentration (Cp) in chimpanzees and if it is feasible to perform TCI in chimpanzees. Ten chimpanzees were anaesthetized for regular veterinary examinations. Propofol was used as an induction or maintenance agent. Blood samples were collected from a catheter in a cephalic vein at 3–7 time points between 1 and 100 min following the propofol bolus and/or infusion in five chimpanzees, or TCI in six chimpanzees. Cp was measured using high-performance liquid chromatography. The Marsh, Schnider and Eleveld human pharmacokinetic models were used to predict Cp for each case and we examined the predictive performances of these models using the Varvel criteria Median PE and Median APE. Median PE and Median APE for Marsh, Schnider and Eleveld models were within or close to the acceptable range. A human TCI pump was successfully maintained propofol Cp during general anesthesia in six chimpanzees. Human propofol pharmacokinetic models and TCI pumps can be applied in chimpanzees.

Enzootic nasal tumor virus type 2 envelope of goats acts as a retroviral oncogene in cell transformation

Enzootic nasal tumor virus type 1 (ENTV-1) (ovine nasal tumor virus) and ENTV-2 (caprine nasal tumor virus) are known to be causative agents of enzootic nasal adenocarcinoma (ENA) in sheep and goats, respectively. Although the nucleotide and amino acid sequences of ENTV-1 and ENTV-2 are quite similar, they are recognized as phylogenetically distinct viruses. The envelope protein of ENTV-1 functions as an oncoprotein in the in vitro transformation of epithelial cells and fibroblasts. Thus, it is the primary determinant of in vivo tumorigenesis in ENA. As per our knowledge, no previous studies have reported in detail the role of ENTV-2 in ENA tumorigenesis. Here, in order to investigate the molecular mechanism of caprine ENA oncogenesis by ENTV-2, we have attempted to identify the transforming potential of ENTV-2 envelope, and investigated the activation of cell signaling pathways in oncogenic transformation. Our findings confirmed that ENTV-2 envelope was capable of inducing oncogenic transformation of rat cell lines in vitro. Further, we found that MAPK, Akt, and p38 were constitutively activated in ENTV-2 envelope-transformed clone cells. In addition, inhibitor experiments revealed that MEK-MAPK and PI3K-Akt signaling pathways are involved in the ENTV-2 envelope-induced cell transformation. These data indicate that ENTV-2 envelope could induce oncogenic transformation by signaling pathways that are also utilized by ENTV-1 envelope.

Antitumor Effect of Sugar-Modified Cytosine Nucleosides on Growth of Adult T-Cell Leukemia Cells in Mice

Adult T-cell leukemia (ATL) is a CD4⁺ T-cell neoplasm caused by human T-cell leukemia virus type I. As the prognosis for patients with ATL remains extremely poor due to resistance to conventional chemotherapy regimens, introduction of novel therapeutic agents is needed. Previous studies have reported that nucleosides 2′-deoxy-2′-methylidenecytidine (DMDC) and its derivative 2′-deoxy-2′-methylidene-5-fluorocytidine (FDMDC) exhibit antitumor activities in T-cell acute lymphoblastic leukemia (T-ALL) and solid tumor cell lines. Another nucleoside, 1-(2-azido-2-deoxy-β-D-arabinofuranosyl)cytosine (cytarazid), is considered a therapeutic drug with antitumor activity in human solid tumors. In this study, we investigated the effects of these nucleosides on cell growth in vitro and in vivo using relevant leukemia cell lines and NOD/Shi-scid, IL-2Rg^null (NOG) mice, respectively. The nucleosides demonstrated significant cytotoxic effects in ATL and T-ALL cell lines. Intraperitoneal administration of FDMDC and DMDC into tumor-bearing NOG mice resulted in significant suppression of tumor growth without lethal side effects. Our findings support a therapeutic application of these nucleosides against tumor progression by targeting DNA polymerase-dependent DNA synthesis in patients with ATL.

Association between maternal active smoking during pregnancy and placental weight: The Japan environment and Children's study

INTRODUCTION

Maternal smoking during pregnancy is a well-known risk factor for reduced birthweight. However, research investigating the association between maternal smoking and placental weight is scarce and inconsistent. Our study was conducted to evaluate the association between maternal smoking and placental weight and placental weight/birthweight ratio (PW/BW ratio).

METHODS

We used data from a birth cohort study, the Japan Environment and Children's Study (JECS). Main outcome measures were placental weight, PW/BW ratio, and the risk of high PW/BW ratio. High PW/BW ratio was defined as PW/BW ratio above the 90th percentile for gestational age and sex of offspring. The association between maternal smoking and placental weight was estimated as crude and as adjusted beta coefficients by applying linear regression analyses. Logistic regression analyses were also performed to estimate the association between maternal smoking and the risk of high PW/BW ratio.

RESULTS

Of the 91,951 pregnant women, the mean placental weight and the mean PW/BW ratio were lowest for the group of women who had never smoked. Smokers had higher odds ratio for high PW/BW ratio compared with non-smokers. Furthermore, among smokers, the mean placental weight and mean PW/BW ratio were lowest in women who smoked less than 5 daily cigarettes, and highest in women who smoked 20 or more daily cigarettes during pregnancy.

DISCUSSION

Placental weight was greater and PW/BW ratio was higher among smokers compared with non-smokers. Moreover, the number of daily cigarettes was positively associated with heavy placental weight.

PERFORMANCE EVALUATION OF HYPERELASTIC MODELS FOR CARBON-BLACK–FILLED SBR VULCANIZATES

The performance of four recently developed hyperelastic material models (HM models) was evaluated by using stress–stretch relationships of filled styrene butadiene rubber vulcanizates with different contents of carbon black (CB) tested under uniaxial tension (UT), pure shear (PS), and equi-biaxial tensile (BT) conditions. The stress–stretch relationships for the PS and BT tests were obtained with a specially designed specimen having higher accuracy than those obtained with an ordinary specimen. The performances of the HM models were compared via the following three evaluations: (1) ability to reproduce the UT, PS, and BT tests; (2) ability to predict the PS and BT test results with material constants identified from the UT test; and (3) correlation between the identified material constants and CB contents. The evaluations based on a combination of the stress–stretch relationships with high accuracy and four recently developed HM models revealed that the HM model activates only the I1 term, which is the first invariant of the right Cauchy–Green tensor, exhibiting good reproducibility and predictability.

Structural and thermodynamic analyses reveal critical features of glycopeptide recognition by the human PILRα immune cell receptor

Before entering host cells, herpes simplex virus-1 uses its envelope glycoprotein B to bind paired immunoglobulin-like type 2 receptor α (PILRα) on immune cells. PILRα belongs to the Siglec (sialic acid (SA)-binding immunoglobulin-like lectin)-like family, members of which bind SA. PILRα is the only Siglec member to recognize not only the sialylated O-linked sugar T antigen (sTn) but also its attached peptide region. We previously determined the crystal structure of PILRα complexed with the sTn-linked glycopeptide of glycoprotein B, revealing the simultaneous recognition of sTn and peptide by the receptor. However, the contribution of each glycopeptide component to PILRα binding was largely unclear. Here, we chemically synthesized glycopeptide derivatives and determined the thermodynamic parameters of their interaction with PILRα. We show that glycopeptides with different sugar units linking SA and peptides (i.e. "GlcNAc-type" and "deoxy-GlcNAc-type" glycopeptides) have lower affinity and more enthalpy-driven binding than the wild type (i.e. GalNAc-type glycopeptide). The crystal structures of PILRα complexed with these glycopeptides highlighted the importance of stereochemical positioning of the O4 atom of the sugar moiety. These results provide insights both for understanding the unique O-glycosylated peptide recognition by the PILRα and for the rational design of herpes simplex virus-1 entry inhibitors.

Rapid Screening by Cell-Based Fusion Assay for Identifying Novel Antivirals of Glycoprotein B-Mediated Herpes Simplex Virus Type 1 Infection

Herpes simplex virus type 1 (HSV-1) is a causative agent for a variety of diseases. Although antiherpetic drugs such as acyclovir have been developed to inhibit virus replication through interaction with DNA kinases, their continuous administration leads to an increase in the frequency of drug-resistant HSV-1, which is an important clinical issue that requires urgent solution. Recently, we reported that the sialylated O-linked sugar T antigen (sTn) and its attached peptide region (O-glycosylated sTn peptide) derived from the HSV-1 glycoprotein B (gB) protein inhibited HSV-1 infection by specifically targeting paired immunoglobulin-like type 2 receptor alpha (PILRα) in vitro. In this study, to further identify novel inhibitors of gB-mediated HSV-1 infection in vitro, we established a cell-based fusion assay for rapid drug screening. Chinese hamster ovary (CHO) cells were transfected with expression plasmids for HSV-1 gB, gD, gH, and gL, and T7 RNA polymerase, and were designated as the effector cells. The CHO-K1 cells stably expressing PILRα were transfected with the expression plasmid for firefly luciferase under the T7 promoter, and were designated as the target cells. The effector and target cells were co-cultured, and luminescence was measured when both cells were successfully fused. Importantly, we found that cell-to-cell fusion was specifically inhibited by O-glycosylated sTn peptide in a dose dependent manner. Our results suggested that this virus-free cell-based fusion assay system could be a useful and promising approach to identify novel inhibitors of gB-mediated HSV-1 infection, and will aid in the development of antiviral therapeutic strategies for HSV-1-associated diseases.

Validation of the optimal site in the neck region for detecting swallowing sounds

Recently, the swallowing sound has been used to detect swallowing events non-invasively. A previous study, using an accelerometer, showed that the site over the lateral border of the trachea immediately inferior to the cricoid cartilage was the optimal site for detecting swallowing sounds. However, the optimal site for detection of the swallowing sound using a microphone remains undetermined. To validate the optimal site in the neck region for detecting swallowing sounds. Fourteen healthy subjects (mean age, 27·6 ± 2·2 years; seven male and seven female) participated in this study. Twenty condenser microphones were attached to 20 sites on the left neck surface to detect swallowing sounds. Participants were instructed to swallow five different stimuli three times as follows: Resting saliva, 1 and 5 mL of Japanese tea, and 1 and 5 mL of yoghurt. Mean relative peak intensity was used to indicate the magnitude of the swallowing sound. Sound spectrograms were used to illustrate differences in the properties of swallowing sounds. Mean relative peak intensity number was highest in sites at the inferior border of the mandible just above the sternocleidomastoid muscle (site 11) and sites over the lateral border of the trachea immediately inferior to the cricoid cartilage (site 8). Comparison of spectrograms showed a greater density distribution of higher frequency components at site 11 compared with site 8. These results indicate that the inferior border of the mandible just above the sternocleidomastoid muscle is the optimal site for the detection of swallowing sounds.

Haematological data for Matsumoto Eosinophilic Shinshu rats as determined by an automated haematology analyser

The Matsumoto Eosinophilic Shinshu (MES) rat originated from an inbred mutant colony of rats with spontaneous eosinophilia. As part of an investigation of the pathogenesis of the MES rat, we examined the haematology data for 106 males and 88 females and age-associated changes using an automated haematology analyser, flow cytometric analysis and morphological examination. The data at 10 weeks of age showed the MES rats had higher counts for eosinophils and neutrophils, slightly higher counts for lymphocytes, monocytes, basophils, and large unstained cells (LUCs), and slightly lower values for the erythrocytic parameters when compared with Sprague-Dawley (SD) rats. In data for MES rats aged 8 to 20 weeks, eosinophil counts increased with age up to 20 weeks together with some increased neutrophil counts. After 11 weeks of age, counts for lymphocytes, monocytes, basophils, and LUCs in the MES rats were also slightly increased. In female MES rats, flow cytometric analysis showed increased counts for pan-T+ cells, but blasts, abnormal granulocytes and lymphocytes were not detected morphologically. The MES rat characterized by the haematological findings could be a useful animal model for studies of hypereosinophilia.

Tolerance to nitroglycerin through proteasomal down-regulation of aldehyde dehydrogenase-2 in a genetic mouse model of ascorbate deficiency

Background and Purpose

L-gulonolactone oxidase-deficient (Gulo^(-/-)) mice were used to study the effects of ascorbate deficiency on aortic relaxation by nitroglycerin (GTN) with focus on changes in the expression and activity of vascular aldehyde dehydrogenase-2 (ALDH2), which catalyses GTN bioactivation.

Experimental Approach

Ascorbate deficiency was induced in Gulo^(-/-) mice by ascorbate deprivation for 4 weeks. Some of the animals were concomitantly treated with the proteasome inhibitor bortezomib and effects compared with ascorbate-supplemented Gulo^(-/-), untreated or nitrate-tolerant wild-type mice. Aortic relaxation of the experimental groups to GTN, ACh and a NO donor was studied. Changes in mRNA and protein expression of vascular ALDH2 were quantified by qPCR and immunoblotting, respectively, and aortic GTN denitration rates determined.

Key Results

Like GTN treatment, ascorbate deprivation induced vascular tolerance to GTN that was associated with markedly decreased rates of GTN denitration. Ascorbate deficiency did not affect ALDH2 mRNA levels, but reduced ALDH2 protein expression and the total amount of ubiquitinated proteins to about 40% of wild-type controls. These effects were largely prevented by ascorbate supplementation or treating Gulo^(-/-) mice with the 26S proteasome inhibitor bortezomib.

Conclusions and Implications

Our data indicate that ascorbate deficiency results in vascular tolerance to GTN via proteasomal degradation of ALDH2. The results support the view that impaired ALDH2-catalysed metabolism of GTN contributes significantly to the development of vascular nitrate tolerance and reveal a hitherto unrecognized protective effect of ascorbate in the vasculature.