Human cytomegalovirus induces DNA-dependent RNA polymerases in human diploid cells.

Endogenous RNA polymerase activity was enhanced in human embryonic cells infected with human cytomegalovirus (HCMV) as determined by the incorporation of [³H]UTP into nuclear monolayers. The increase in activity was first detected about 18 hr postinfection, and reached a level 3-fold higher by 48 hr. This kinetics of enhancement coincided with the kinetics of [³H]uridine incorporation into RNA in the infected, intact cells. The treatment of HCMV-infected cells with either cycloheximide or actinomycin D during the first 6 hr of infection practically abolished the subsequent enhancement of endogenous RNA polymerase activity, suggesting a key role of a HCMV-induced early protein(s) in the stimulation of endogenous RNA polymerase activity. Multiple forms of cellular RNA polymerases from HCMV- or mock-infected cells were separated by DEAE-Sephadex chromatography and assayed using calf thymus DNA as a template. In HCMV-infected cells, there was a marked increase in the activity of three major classes of RNA polymerases; the activity corresponding to RNA polymerase II increased 16-fold and those corresponding to polymerases I and III 6- and 3-fold, respectively.     

Thapsigargin-induced endothelium-dependent triphasic regulation of vascular tone in the porcine renal artery.

1. To elucidate the role of thapsigargin-induced Ca2+ entry in endothelial cells in the regulation of vascular tone, changes in Ca2+ and force of smooth muscle were simultaneously monitored in fura-2-loaded strips of porcine renal artery. 2. During phenylephrine-induced sustained contraction, thapsigargin caused an endothelium-dependent triphasic response; an initial relaxation, a subsequent transient contraction, and a sustained relaxation. The initial relaxation and the contraction were associated with a decrease and an increase in [Ca2+]i, respectively. There was no apparent [Ca2+]i decrease during the sustained relaxation. Thapsigargin-induced responses were observed at 10-8 M and higher concentrations, with the maximum response observed at 10-6 M. 3. The transient contraction was inhibited by a cyclo-oxygenase inhibitor (10-5 M indomethacin), a thromboxane A2 (TXA2)/prostaglandin H2 (PGH2) receptor antagonist (10-5 M ONO-3708), and a TXA2 synthase inhibitor (10-5 M OKY-046). 4. During the phenylephrine-induced contraction in the presence of indomethacin, thapsigargin caused an initial, but not a sustained relaxation, in the presence of Nomega-nitro-L-arginine methylester (L-NAME). During the contraction induced by phenylephrine plus 40 mM K+-depolarization in the presence of indomethacin, thapsigargin induced both a transient and a sustained relaxation. However, these relaxations were completely abolished in the presence of L-NAME. 5. Thapsigargin caused a large Ca2+ elevation in cultured endothelial cells of the renal artery. The concentration-response relation was thus similar to that for force development in the arterial strips. 6. In conclusion, thapsigargin-induced Ca2+ entry in endothelial cells led to triphasic changes in the tone of the porcine renal artery. The endothelium-dependent contraction was mediated mainly by TXA2. Nitric oxide and hyperpolarizing factor are both involved in the initial relaxation. However, a sustained relaxation was observed which mainly depended on nitric oxide.     

Left Ventricular Abnormality and Covert Atrial Fibrillation in Embolic Stroke of Undetermined Source

Aims: The relationship between left ventricular (LV) function and AF detection in embolic stroke of undetermined source (ESUS) patients with insertable cardiac monitors (ICMs) remains unclear. We investigated the association between LV function and AF detection in patients with ESUS after ICMs implantation. Methods: We enrolled patients with ESUS who underwent ICMs implantation from September 2016 to September 2020 using a single-center, prospective registry. LV systolic and diastolic functions were assessed on precordial echocardiography by LV fractional shortening (LVFS) and average E/e’, respectively. Associations between characteristics of LV function and detection of AF by ICMs were analyzed. Results: Participants comprised 101 patients (median age, 74 years; male, 62%). During a median follow-up period of 442 days (interquartile range (IQR), 202–770 days), AF was detected in 24 patients (24%). Median duration from ICMs implantation to AF detection was 71 days (IQR, 13–150 days). When LVFS and E/e’ were dichotomized by cutoff value, each of low LVFS (＜35.5%; adjusted hazard ratio (HR), 4.77; 95% confidence interval (CI), 1.77–12.9) and high E/e’ (≥ 8.65; adjusted HR, 4.56; 95%CI, 1.17–17.7) were independently associated with AF detection after adjusting for age and sex. When patients were divided into four groups according to dichotomized LVFS and E/e’, the combination of low LVFS and high E/e’ was independently associated with AF. Conclusions: In patients with ESUS after ICMs implantation, the LV characteristics of low LVFS and high E/e’ were associated with AF detection.     

IgG4-Related Lung Disease Exhibiting the Invasion into the Diaphragm: A Case Report

Immunoglobulin G4-related disease (IgG4-RD) is a fibroinflammatory condition which involves various organs. This is a very rare case of IgG4-related lung disease (IgG4-RLD) with the invasion into diaphragm. The patient was a 71-year-old man with a long-term exposure to asbestos who had a mass shadow in the left lower lung lobe, which was suspected to invade the left diaphragm on computed tomography (CT). Positron emission tomography (PET)/CT also presented an avid intake of fluorodeoxyglucose in the mass, which suspected lung cancer. Although bronchoscopic biopsy could not lead to the definite diagnosis, we performed left lower lobectomy combined with the resection of left diaphragm. The specimen showed the features of IgG4-RLD on pathology: the vein stenosis and fibrosis around the vein, the infiltration of IgG4-positive cells, and IgG cells to IgG4 cells ratio of 40%. Furthermore, there were inflammatory cells infiltrating to the diaphragm.     

A Rare Case of Rheumatoid Arthritis with Tocilizumab-induced Intestinal Mucosal Injury

Intestinal mucosal injury that develops as a complication of tocilizumab (TCZ) is usually associated with diverticulosis. We herein report a rare case of TCZ-induced intestinal mucosal injury in the absence of diverticulosis. A 74-year-old woman suffering from rheumatoid arthritis started taking TCZ. Six months later, she complained of hematochezia and abdominal pain. Colonoscopy revealed multiple ulcers spreading from the cecum to the transverse colon but no diverticulosis. These lesions were cured at three months after the discontinuation of TCZ. We should consider TCZ as a risk factor for intestinal mucosal injury, even if patients have no history of intestinal disease associated with diverticulosis.     

Treatment of metastatic bone lesions in the upper extremity: indications for surgery

Pathological fractures caused by metastatic malignant disease have been the subject of increasing interest in recent years. This article describes our experience with the treatment of metastatic bone disease of the upper extremity and our attempt to clarify the indications for different surgical procedures. Of 53 patients with metastatic lesions to the upper extremity, 20 who had been surgically treated were analyzed retrospectively. These comprised 13 men and 7 women with a mean patient age of 62 years. The most common primary tumors to metastasize were lung and liver, with the humerus involved in 12 cases and the scapula and forearm in 4 cases each. Four patients with scapula and forearm involvement underwent tumor resection due to uncontrollable tumor size, while 3 were successfully treated by selective arterial embolization. Three metastases to the humeral head were reconstructed with endoprosthesis, but functional restriction was noted. Five cases with metastases to the humeral shaft were treated with tumor curettage, internal fixation using intramedullary nailing, adjuvant cryosurgery, and cementing. This achieved good results for pain relief and functional restoration with minimal complications. Two metastases to the humeral condyle were unable to be stabilized with plate and locking screws. Metastatic lesions to the scapula and forearm are commonly treated nonsurgically, but some patients with uncontrollable tumor mass require surgical resection. Endoprosthetic replacement is recommended if the lesion involves the humeral head or condyle. Most patients with the humeral shaft lesion are likely to benefit from tumor curettage, intramedullary nailing with locking screw, and cementing.     

Hepatic arterial buffer response after pediatric living donor liver transplantation: report of a case

Background

Excessive portal pressure at an early stage after living-donor liver transplantation (LDLT) can damage sinusoidal endothelial cells and hepatocytes through shear stress leading to graft failure, or hepatic arterial complications due to low hepatic artery flow from a hepatic arterial buffer response. We encountered a case in which excessive portal vein flow was observed from an early stage after pediatric LDLT. The hepatic artery flow decreased due to a hepatic arterial buffer response.

Case report

A 6-month-old boy with biliary atresia showed excessive portal vein flow early after LDLT with a decreasing hepatic artery flow without anastomotic stenosis from postoperative day 3. The PV flow gradually exhibited a decrease at approximately postoperative day 8 and, similtaneously, hepatic artery flow exhibited improvement.

Conclusion

Because excessive portal pressure after LDLT is reversible, it has been suggested that it may be possible to prevent the progress of hepatic arterial complications if temporary portal pressure modulation can be performed for cases among the high-risk group for hepatic arterial complications.     

Intramuscular hemangioma of the upper extremity in infants and children

PURPOSE: Intramuscular hemangiomas (IMHs) are benign tumors comprising just 0.8% of all hemangiomas and are extremely rare in the upper limbs. These tumors can pose diagnostic as well as therapeutic challenges for orthopaedic surgeons, especially in younger children. We reviewed cases of IMH of the upper extremity in infants and children from our institute. METHODS: Six consecutive patients underwent surgical treatment for IMH in our hospital. There were 4 girls and 2 boys. Long-standing pain and swelling were common symptoms except in a 1-year-old boy. Tumors were evaluated by radiography, computed tomography, magnetic resonance imaging, and angiography. RESULTS: After a mean follow-up of 42 months, all patients except one were free of pain and without tumor recurrence or functional impairment. Minimal symptoms remained in a 6-year-old boy who underwent biopsy only. CONCLUSION: Magnetic resonance imaging is the most useful evaluation for IMH because it not only delineates the extent of tumor but also reveals characteristic structures. For young children with IMH, wide excision is the treatment of choice to prevent local recurrence, but every patient should be treated individually after evaluating the patient's age, tumor location and invasion, and cosmetic considerations. LEVEL OF EVIDENCE: Therapeutic study-level III.