Cytomegalovirus infection and wheezing in infants

Background: Bronchial asthma‐like symptoms such as wheezing are commonly associated with respiratory tract infection including respiratory syncytial virus (RSV) infection in infants. No study on the association of wheezing with cytomegalovirus (CMV) infection in infancy has been reported, although CMV infection has been observed to play some role in prolonged and intractable wheezing in limited cases. Methods: The present study investigated 40 hospitalized infants who presented with first‐episode wheezing between October 2003 and September 2004. Nasopharyngeal aspirates were tested for RSV, and serum antibodies against CMV were measured. As controls, age‐matched infants with no wheezing were examined for CMV serostatus. Results: RSV‐antigen was detected in 21 subjects (53%), and seven (18%) were considered primary CMV infection serologically. Primary CMV infection was found more often in the wheezers than in the controls although the difference was not statistically significant (P = 0.06). The incidence of splenomegaly was significantly higher in wheezers with CMV infection (86%) than in those with RSV infection or without either infection. The duration of wheezing, fever, and radiographic and laboratory findings during hospitalization were not significantly different. Conclusions: CMV infection based on serologic diagnosis should be considered in infants with first wheezing episode and particularly those with splenomegaly.     

Triazine Derivatives Inhibit Rat Hepatocarcinogenesis but Do Not Enhance Gap Junctional Intercellular Communication

We report here novel candidate chemopreventive agents active against experimental hepatocarcino-genesis. The triazine derivatives 6-(2-chlorophenyl)-2,4-diamino-l,3,5-triazine (2CPDAT), 6-(3-chlorophenyl)-2,4-diamino-l,3,5-triazine (3CPDAT), 6-(4-chlorophenyl)-2,4-diamino-l,3,5-triazine (4CPDAT), 6-(4-pyridyl)-2,4-diamino-l,3,5-triazine (PyDAT), and 6-(pyridine JV-oxid-4-yl)-2,4-diamino-l,3,5-triazine (PyNODAT), synthesized in our laboratory, in addition to 6-(2,5-dichloro-phenyl)-2,4-diamino-l,3,5-triazme (DCPDAT), or irsogladine, which is a widely used anti-ulcer drug, were investigated for potential chemopreventive effects in a rat liver medium-term bioassay system. A significant inhibitory influence on enzyme-altered liver foci was found for 2CPDAT, 3CPDAT, 4CPDAT, and PyNODAT, but not for DCPDAT or PyDAT, The involvement of gap jnnctional intercellular communication in the inhibition was studied, but no change in gap Junctional intercellular communication capacity in rat liver cells in vitro or in gap junction protein (connexin 32) expression in rat liver in vivo was noted. These results indicate that, although these irsogladine analogues exert inhibitory effects on rat liver carcinogenesis, their action is independent of modification of gap Junctional intercellular communication.     

In vivo Retrovirus-mediated Herpes Simplex Virus Thymidine Kinase Gene Therapy Approach for Adult T Cell Leukemia in a Rat Model

We have previously demonstrated that human T-lymphotropic virus type I (HTLV-tax-expressing human T cell lines are selectively eliminated in the presence of aciclovir, using a retroviral vector carrying the herpes simplex virus thymidine kinasc (HSV TK) gene under the control of the long terminal repeat (LTR) of HTLV-I. Based on these findings in vitro , we investigated whether this system could also be effective in vivo , using a rat model. Following infection of the HTLV-I-trans-formed and tot-expressing rat T cell line TARS-1 with this retrovirus (LNLTK virus), high levels of HSV TK expression were observed and resulted in increased susceptibility to ganciclovir (GCV). Tumors were generated by subcutaneous injection of TARS-1 in newborn syngeneic WKA/H rats. While the tumors derived from infected TARS-1 cells with control virus, as well as uninfected cells, continued to grow in all the rats with or without administration of GCV, those derived from LNLTK-infected cells exhibited dramatic regression upon GCV treatment. These results indicate that the HTLV-I LTR-HSV TK system also causes selective elimination of HTLV-I-transformed, (ax-expressing T cells in vivo. Therefore, our present study may provide a rationale for clinical gene therapy against adult T cell leukemia.     

Induction of Specific Cytotoxic T Lymphocytes against Autologous Brain Tumor by Crossreactive Allo-tumor Cell Stimulation

Cytotoxic T lymphocytes (CTL) against autologous malignant brain tumor were generated in peripheral blood lymphoid cells (PBL) prepared from a patient with a malignant brain tumor by stimulation of the cultured PBL for 7 days with attenuated Crossreactive malignant melanoma (MM2) cells pretreated with mitomycin C. The Crossreactive MM2 cells were effective for antigen stimulation for CTL induction in place of autologous glioblastoma cells, which are difficult to expand in culture. The optimal ratio between nylon wool-passed T lymphocytes and nylon wool-adherent accessory cells to induce CTL in the patient's PBL was found to be 25 to 1. In vitro -activated CTLs induced by MM2 were cytotoxic not only to MM2, but also to the autologous tumor cells in an HLA class I-restricted manner, and their surface phenotype was found to be CD3⁺ and CD8⁺. CTL therapy using cross-reactive allogeneic tumor cells as the stimulator could be clinically valuable to treat malignant brain tumors.     

Mother-to-child transmission of human T-lymphotropic virus type I (HTLV-I): An extended follow-up study on children between 18 and 22-24 years old in Okinawa,Japan

The significant difference observed between the seroprevalence of HTLV-I in adults and in children is as yet unexplained. To evaluate a hypothetical explanation of the existence of seroconversion cases of ?seronegative carriers”? for this phenomenon, 21 of 55 children who had been born to seropositive mothers and who remained seronegative until the age of 18 years were further followed up at the ages of 22 and/or 24 years. None of the 21 seronegative children born to seropositive mothers seroconverted, either at 22 years or at 24 years. In addition, the polymerase-chain-reaction (PCR) technique could not prove the existence of the HTLV-I provirus genome in peripheral mononuclear cells (PBMC) of 10 of these children. Our results fail to prove the possibility of viral latency of HTLV-I in mother-to-child transmission. Therefore, the hypothetical seroconversion of ?seronegative carriers”? after adulthood can not be an explanation.     

DNA single- and double-strand breaks produced by ferric nitrilotriacetate in relation to renal tubular carcinogenesis

Fe(III) bound to a chelator, nitrilotriacetate (NTA), has beenreported to induce a high frequency of adenocarcinoma localizedto the proximal tubules of the kidney in rodents. In order toexamine possible mechanisms for the carcinogenic activity, weinvestigated the in vitro production of single- and double-strandbreaks in DNA mediated by iron alone or Fe-NTA chelate usingsupercoiled plasmid pZ189. Neither Fe(III) nor NTA alone brokeDNA. Fe(III) plus NTA together mediated the efficient oxidativeproduction of DNA single-and double-strand breaks in the presenceof reducing agents (ascorbate » H₂O₂ > cysteine). TheFe(III): NTA ratio (1:4) that was found to be optimal for DNAstrand breakage was similar to the ratio that produced adenocarcinomasin rodents. Maximal Fe-NTA-mediated DNA damage in vitro wasinduced under conditions of neutral pH, low ionic strength,presence of reducing agent and absence of albumin. These conditionsare present exclusively in the cortical proximal tubules ofthe kidney, the only location where toxicity and carcinogenicityof Fe-NTA has been observed. Thus, localized DNA damage mayexplain the anatomic site preferred by Fe-NTA-induced carcinogenesis.     

The Expression of Invasive Behavior of Differentiated Squamous Carcinoma Cell Line Evaluated by an in vitro Invasion Model

In order to elucidate the factors contributory to the expression of invasiveness of oral squamous cell carcinoma, we conducted biochemical and morphological comparisons of well differentiated squamous carcinoma cell line OSC-19 (oral squamous cell carcinoma) and undifferentiated carcinoma cell line KB, both cultured on 3T3 cell-embedded collagen gel ( in vitro invasion model). OSC-19 cells invaded 3T3 cell-embedded collagen gel, while KB cells and OSC-19 cells on 3T3 cell-free gel matrix were less invasive. Cultured OSC-19 cells were characterized by lower proliferating activity, lower secretion of laminin and higher secretion of fibronectin than those of KB cells. Although the basement membrane with deposition of laminin and type IV collagen was formed, it was discontinuous at the invasion front. Gelatin zymography and western blotting showed matrix metalloproteinases (MMP), i.e., 72 kDa gelatinase (MMP-2) and 92 kDa gelatinase (MMP-9). Gelatinolytic activity was assayed, and was higher in OSC-19 cells than in KB cells or OSC-19 cells of the 3T3 cell-free model. By immuno-histochemical analysis, MMP-2-positive cells were found scattered in both cell lines without any preferential localization, and the positivity for MMP-9 was localized in the invasion front of OSC-19 cells. These results strongly suggest that the invasiveness of squamous cell carcinoma is well correlated with cell-matrix adhesion by fibronectin and with focal elaboration of metalloproteinases, especially MMP-9, which play a major role in degrading the extracellular matrix components.     

Genetic Changes and Histopathological Grades in Human Hepatocellular Carcinomas

Loss of heterozygosity (LOH) on chromosomes 1p, 4q, 5q, 8p, 13q, 16q, 17p, and 22q, and mutation of the p53 gene were simultaneously analyzed in 63 hepatocellular carcinomas (HCCs) with distinct histopathological grades, 80% of the tumors being from patients who had been exposed to hepatitis B virus (HBV) or hepatitis C virus (HCV). The frequencies of LOH on 8 chromosomes were 0–25% in 10 well differentiated HCCs, LOH being observed on 4q, 5q and 17p, 21–53% in 26 moderately differentiated HCCs, LOH on 8p and 17p being high, and 29–75% in 27 poorly differentiated HCCs, LOH on 17p, 4q and 8p heing the most frequent. p53 gene mutation was detected in moderately and poorly differentiated HCCs at 15% and 52%, respectively, but not at all in well differentiated HCCs. Of the mutations detected, 42% were transition mutation and only 5% were CpG transition, in contrast to the high frequencies of these types of mutations in colon tumors (78% and 54%, respectively). LOH on every chromosome and p53 mutation were more frequent in more advanced tumors, and accumulation of genetic changes increased with increase of the histopathological grade. Frequency of genetic changes in HCCs from HBV-positive patients was comparable to that from HCV-positive patients. The present results suggest that accumulation of genetic changes in multiple tumor suppressor genes, especially LOH on 17p, 4q and 8p, and mutation in p53 gene, are involved in the progression of liver cancer, and LOH on 17p and 4q precedes other genetic changes. Differences in the direction of p53 mutation between HCC and colon carcinoma suggest that liver carcinogens are distinct from colon carcinogens. Furthermore, mechanisms affecting the frequency of LOH in HCCs in HBV-infected patients may be similar to those in HCV-infected patients.     

Resection margin in patients with gastric cancer associated with esophageal invasion: Clinicopathological study

We investigated the correlations between resection margin involvement by carcinoma and a number of clinicopathological features in patients with gastric cancer and esophageal invasion. From January 1968 to December 1988, 1,040 patients with carcinoma of the stomach underwent gastric resection. Thirty-nine patients had tumor infiltration of the esophagus on histological examination of the resected specimens. The patients were divided into two groups on microscopic examination: those in whom the resection margin was less than 5 mm wide, and those in whom it exceeded 5 mm microscopically. There were 6 and 33 patients in the narrow and wide margin groups, respectively. There were statistically significant differences in tumor size, depth of cancer invasion, and macroscopic appearance between the two groups. The risk of resection margin involvement was high in tumors with the following features: large Borrmann type 4 tumor (macroscopic appearance and size) and infiltrative carcinoma (depth of invasion). © 1993 Wiley-Liss, Inc.