Serum regulated upon activation, normal T cell expressed and presumably secreted concentrations and eosinophils in respiratory syncytial virus infection

BACKGROUND: The aim of this study was to characterize respiratory syncytial virus (RSV) infection. To do this, the authors evaluated eosinophil counts and chemokines including regulated upon activation, normal T cell expressed and presumably secreted (RANTES) in children with RSV, adenoviral, and influenza virus infections. METHODS: The authors enrolled 80 patients who had been diagnosed with acute viral respiratory infection caused by RSV, adenoviral, or influenza viruses. In total, 35 patients (Group A) had RSV infection, 18 (Group B) had adenoviral infection, and 27 (Group C) had influenza virus infection. The authors evaluated clinical manifestations, white blood cell and eosinophil counts, and serum chemokines including RANTES concentrations in the acute and recovery phases in each group. RESULTS: In recovery phase, eosinophil counts were higher in Group A than Groups B and C. In Group A, eosinophil counts were higher in recovery phase than in the acute phase. In Group A, serum RANTES concentration was significantly higher in the recovery phase than in the acute phase (132+/-76 pg/mL vs 52+/-25 pg/mL, P<0.05). CONCLUSION: The findings suggest that high values of RANTES in children with RSV infection may be associated with the presence of eosinophils and be an important mediator of inflammatory response.     

High CD4/CD45RO+ and CD8/CD45RO+ frequencies in children with vaccine-modified measles

BACKGROUND: Despite availability and wide vaccine coverage, measles infections still occur especially in developing countries. An outbreak of measles occurred among previously immunized older Ghanaian children who had milder clinical symptoms with measles-specific IgG antibodies that could have been attributed to secondary vaccine failure, suggesting that the infection was vaccine-modified measles (VMM). METHODS: Two-color immunophenotyping of the peripheral blood mononuclear cells was performed at acute, recovery and convalescence phases for 19 VMM patients (mean age 6.2 +/- 3.5 years) using flow cytometry, and compared with that of 20 healthy, sex- and age-matched controls. RESULTS: The results showed a significantly higher memory helper (CD4(+)/CD45RO(+)) cell frequency and increased suppressor cell (CD8(+)/CD45R0(+)) frequency in VMM patients compared to healthy controls. There were no complications and all the patients recovered completely. CONCLUSIONS: These findings show that the mild symptoms in patients with VMM may have correlated with the increase of memory T cells, which is in sharp contrast with previous reports on acute measles infection. This may suggest that the intact immunologic memory cells could have been crucial for the resolution of VMM.     

Inhibition of natural killer (NK) cell activity against varicella-zoster virus (VZV)-infected fibroblasts and lymphocyte activation in response to VZV antigen by nitric oxide-releasing agents

The addition of nitric oxide (NO)-releasing agents, S-nitroso-N-acetyl-DL-penicillamine (SNAP), 1-hydroxy-2-oxo-2,3-bis(2-aminoethyl)-1-triazene (NOC18), 30{(±)-(E)-ethyl-2′-[(E)-hydroxyimino]-5-nitro-3-hexenecarbamoyl}-pyridine (NOR4) significantly inhibited NK cell activity against VZV-infected cells, while antibody-dependent cell-mediated cytotoxicity (ADCC) against VZV-infected cells was unaffected. Interferon-alpha (IFN-α) production by non-adherent peripheral blood mononuclear cells (NPBMC) cultured with VZV-infected cells was decreased by the addition of NO-releasing agents. Lymphocyte proliferation and the expression IL-2 receptor (CD25) in response to VZV antigen were also inhibited by the addition of NO-releasing agents. These results suggest that the production of NO by an inflammatory process may lead to inhibition of NK cell- and T cell-mediated immunity to VZV infection.     

Prenatal and postnatal histories of very low birthweight infants who developed hepatoblastoma*

BACKGROUND: Hepatoblastoma in children of very low birthweight (< 1500 g) is increasing in Japan and this has suggested the presence of either a genetic or environmental etiology. This study was aimed at revealing common prenatal and postnatal histories, including family history of hepatoblastomas in children of very low birthweight. METHODS AND RESULTS: The medical records of 15 patients, nine boys and six girls, were reviewed. The patients were diagnosed at the age of 6-77 months (median 16 months). Their birthweight ranged from 560 to 1380 g (median 826 g) and the gestational age was 23-33 weeks (median 25 weeks). No parents were exposed to any occupational risk factors and there were no characteristic features in the parents' history or the maternal reproductive history, although one patient was born to a mother who had taken a contraceptive before she got pregnant with the patient as a result of in vitro fertilization. A ventricular septal defect and an atresia of the external auditory canal were congenital anomalies seen in the patients, but congenital anomalies associated with hepatoblastoma were not seen. Early postnatal illnesses included respiratory distress syndrome in six patients, symptomatic patent ductus arteriosus in three patients, chronic lung disease in seven patients, cytomegalovirus hepatitis in one patient and cholelithiasis in one patient. Oxygen therapy was given to 13 patients for a period of 4-508 days (median 112 days) and lengths of oxygen therapy and assisted ventilation were significantly longer in patients with a stage IIIB or IV tumor than those with a stage II or IIIA tumor (P = 0.0040 and 0.0190, respectively). Furosemide was used in 13 patients for a period of 6-460 days (median 88 days) and the length of the treatment was also significantly longer in patients with advanced tumors (P = 0.0420). Among the patients at 23-25 weeks of gestation, these treatments tended to be longer in patients with a stage IIIB or IV tumor than those with a stage II or IIIA tumor. CONCLUSIONS: These results suggest the presence of an environmental etiology, rather than a genetic one, which is responsible for the development of hepatoblastoma in children of very low birthweight. Close monitoring of the children after being discharged from the neonatal intensive care unit is essential and a case-control study is necessary to identify risk factors for hepatoblastoma in children of very low birthweight.     

Conductive Properties of the Reentrant Pathway of Ventricular Tachycardia During Entrainment From Outside and Within the Zone of Slow Conduction

Ventricular tachycardia (VT) was entrained with rapid ventricular pacing outside and within the zone of slow conduction (SCZ), and the conductive properties of the reentrant pathway were compared between the two pacing sites. Underlying heart diseases were old myocardial infarction (n = 2), postoperative tetralogy of Fallot (n = 1) or double outlet of the right ventricle (n = 1), dilated cardiomyopathy (n = 1), and pulmonary regurgitation of unknown cause (n = 1). Rapid pacing was continued for 5–10 seconds, and the time interval from paced stimulus to the entrained electrogram at the exit from SCZ (St-Ex) or to the QRS complex (St-QRS) was measured. Rapid pacing was performed at three or more cycle lengths after a decrement in steps of 10 msec. During rapid pacing outside of SCZ and entrainment of VT, constant fusion and progressive fusion were observed, and St-Ex and St-QRS showed the same response pattern: either a frequency dependent prolongation in 4 of 7 VTs or a constant time interval in the others VTs. When rapid pacing was attempted within SCZ, the response of the time intervals from paced site to the QRS (St-QRS) was the same as those observed during pacing outside SCZ except for one VT. In VT with repaired tetralogy of Fallot, the frequency dependent prolongation was observed during pacing from outside of SCZ but not within SCZ. Diseased myocardium extending widely into the outflow tract of the right ventricle may be responsible for the frequency dependent prolongation of St-Ex. In conclusion, the conductive property of the reentrant pathway might be assessed by observing the response patterns of St-Ex or St-QRS interval during transient entrainment of VT outside of SCZ, but exceptions may exist.