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Biomedical subjects

M W Shaw

Publications and source records attributed to M W Shaw.

At least 19 recordsLinked to original sources
PubMed2004

METH-2 silencing and promoter hypermethylation in NSCLC.

The antiangiogenic factor METH-2 (ADAMTS-8) was identified in a previous dual-channel cDNA microarray analysis to be at least two-fold under-represented in 85% (28 out of 33) of primary non-small-cell lung carcinomas (NSCLCs). This observation has been validated in an independent series of NSCLCs and adjacent normal tissues by comparative multiplex RT-PCR, and METH-2 mRNA expression was dramatically reduced in all 23 tumour samples analysed. Immunohistochemical analysis of the same sample set demonstrated that METH-2 was strongly expressed in 14 out of 19 normal epithelial sites examined but only one out of 20 NSCLCs. DNA methylation analysis of the proximal promoter region of this gene revealed abnormal hypermethylation in 67% of the adenocarcinomas and 50% of squamous cell carcinomas, indicating that epigenetic mechanisms are involved in silencing this gene in NSCLC. No homozygous deletions of METH-2 were found in lung cancer cell lines. Allelic imbalance in METH-2 was assessed by an intronic single nucleotide polymorphism (SNP) assay and observed in 44% of informative primary samples. In conclusion, the downregulation of METH-2 expression in primary NSCLC, often associated with promoter hypermethylation, is a frequent event, which may be related to the development of the disease.

ADAM Proteins↗
PubMed2000

Influenza A virus infection complicated by fatal myocarditis.

Influenza virus typically causes a febrile respiratory illness, but it can present with a variety of other clinical manifestations. We report a fatal case of myocarditis associated with influenza A infection. A previously healthy 11-year-old girl had malaise and fever for approximately 1 week before a sudden, witnessed fatal collapse at home. Autopsy revealed a pericardial effusion, a mixed lymphocytic and neutrophilic myocarditis, a mild lymphocytic interstitial pneumonia, focal bronchial/bronchiolar mucosal necrosis, and histologic changes consistent with asthma. Infection with influenza A (H3N2) was confirmed by virus isolation from a postmortem nasopharyngeal swab. Attempts to isolate virus from heart and lung tissue were unsuccessful. Immunohistochemical tests directed against influenza A antigens and in situ hybridization for influenza A genetic material demonstrated positive staining in bronchial epithelial cells, whereas heart sections were negative. Sudden death is a rare complication of influenza and may be caused by myocarditis. Forensic pathologists should be aware that postmortem nasopharyngeal swabs for viral culture and immunohistochemical or in situ hybridization procedures on lung tissue might be necessary to achieve a diagnosis. Because neither culturable virus nor influenza viral antigen could be identified in heart tissue, the pathogenesis of influenza myocarditis in this case is unlikely to be the result of direct infection of myocardium by the virus. The risk factors for developing myocarditis during an influenza infection are unknown.

Antigens, Viral↗
PubMed2000

Molecular correlates of influenza A H5N1 virus pathogenesis in mice.

Highly pathogenic avian influenza A H5N1 viruses caused an outbreak of human respiratory illness in Hong Kong. Of 15 human H5N1 isolates characterized, nine displayed a high-, five a low-, and one an intermediate-pathogenicity phenotype in the BALB/c mouse model. Sequence analysis determined that five specific amino acids in four proteins correlated with pathogenicity in mice. Alone or in combination, these specific residues are the likely determinants of virulence of human H5N1 influenza viruses in this model.

Adolescent↗
PubMed1998

Generation of influenza transfectants using purified recombinant nucleocapsid protein.

Affinity-purified type A influenza virus nucleocapsid protein expressed by a recombinant baculovirus vector was used in in vitro RNA transcription reactions to create RNP complexes containing a synthetic influenza A virus NS gene. When used in transfection assays, the baculovirus-expressed NP was shown to be biologically active allowing the efficient isolation of transfectant viruses containing the artificially-introduced NS gene. The results demonstrate that NP is the only virion protein necessary in the reconstituted RNP complexes used for transfection thus eliminating the need for purified RNP complexes containing active polymerase.

Baculoviridae↗
PubMed1996

Genetic variation in neuraminidase genes of influenza A (H3N2) viruses.

Nucleotide sequences of the neuraminidase (NA) genes of 33 influenza A (H3N2) epidemic strains isolated between 1968 and 1995 were analyzed to determine their evolutionary relationships. Phylogenetic analysis using the DNA maximum-likelihood method indicates that the NA genes of recent H3N2 field strains, like their hemagglutinin genes (HA), have evolved as two distinct lineages represented by the vaccine strains. A/Beijing/353/89 and A/Beijing/32/92 for A/Shanghai/24/ 90). Furthermore, genetic reassortment of NA genes between the two lineages occurred during their circulation. Genetic reassortants, which bear an A/Beijing/32/92-like HA and an A/Beijing/353/89-like NA, have circulated worldwide and are representative of current influenza A (H3N2) epidemic strains. The mutation rate of the NA gene was found to be 2.28 x 10(-3) per nucleotide site per year with 4.2% of the mutations resulting in amino acid substitutions. Thirty-five percent of the amino acid substitutions was located in sites previously suggested to be reactive to antibody. Amino acid residues involved in NA enzyme activity have been conserved. Seven potential glycosylation sites identified in the NA of A/Hong Kong/8/68 virus were conserved by the majority of isolates, with more recently circulating viruses having an additional glycosylation site. Comparison of the rate of amino acid substitutions in the NA stalk to that of entire NA revealed high variability in this region. These findings demonstrate the importance of closely monitoring both the HA and the NA genes of influenza viruses to aid vaccine strain selection.

Amino Acid Sequence↗
PubMed1996

Human papillomavirus DNA in malignant and hyperplastic prostate tissue of black and white males.

This study hypothesized that human papillomavirus (HPV) infection is associated with increased prostate cancer risk, and that the 40% higher incidence rate in blacks is attributable to a greater prevalence of oncogenic viral DNA in prostatic tissues. Viral L1 and E6 gene sequences were polymerase chain reaction (PCR) amplified in archival tissues from 56 prostate cancer cases and 42 hyperplastic controls. L1 amplimers were hybridized by dot blot to HPV L1 generic probes, as were E6 amplimers to E6 probes specific for HPV 6, 11, 16, 18, 31, 33, and 45. 12.5% of cases and 9.5% of controls were HPV positive by L1 hybridization (age/race adjusted odds ratio = 1.66, 95% confidence interval = 0.33, 8.37). Four of 52 (7.7%) blacks were HPV positive compared to 7 of 46 (15.2%) whites. However, none of the L1-positive samples hybridized to the E6 type-specific probes, and positive results were not replicable using a broader spectrum of PCR primers and probes. These data suggest that HPV infection is not a significant risk factor for prostate cancer and does not explain the excess cancer risk in blacks.

Adenocarcinoma↗
PubMed1994

A program to address the special needs of drug-exposed children.

The Ravenswood-Stanford Coalition for At-Risk Children promotes school success by intervening with K-3 students identified as drug-exposed, either prenatally or environmentally, enabling them to remain in regular classrooms rather than diverted to special education. This goal was accomplished through professional partnerships, home involvement, individual intervention plans, special school-based services, and mentorships. Results from the project indicate these children are not significantly different from their peers; home involvement promotes better school linkages and reinforces positive behavior change; appropriate short-term, school-based services can increase academic and behavioral performance; dedicated volunteers working individually with students accelerate change processes; and these special at-risk students must be assigned to caring, supportive, and predictable classrooms.

Child↗
PubMed1993

A persistent infection in MDCK cells by an influenza type B virus.

A persistent infection in Madin Darby Canine Kidney (MDCK) cells by an influenza B virus (B/Tecumseh/63/80) has been established and characterized. Virus recovered from the persistent state titrated lower in relation to the parental wild-type (wt) that initiated the infection as measured by hemagglutination and egg and tissue culture infectious dose, suggesting that the virus is a less cytopathic variant of the original wt virus. The persistent virus (pv) has decreased cytopathology for both MDCK and primary chick kidney (PCK) cell lines, and exhibits different RNA and protein electrophoretic migrations. Plaques of the persistent virus are smaller and take longer to appear, indicating that the pv is a slower growing variant of the wt. The small plaque mutant phenotype may play a role in the maintenance of the persistent infection in MDCK cells. The pv differs from the wt antigenically and in its ability to form deposits of uric acid-like crystals beneath the culture monolayers.

Animals↗
PubMed1992

New aspects of influenza viruses.

Influenza virus infections continue to cause substantial morbidity and mortality with a worldwide social and economic impact. The past five years have seen dramatic advances in our understanding of viral replication, evolution, and antigenic variation. Genetic analyses have clarified relationships between human and animal influenza virus strains, demonstrating the potential for the appearance of new pandemic reassortants as hemagglutinin and neuraminidase genes are exchanged in an intermediate host. Clinical trials of candidate live attenuated influenza virus vaccines have shown the cold-adapted reassortants to be a promising alternative to the currently available inactivated virus preparations. Modern molecular techniques have allowed serious consideration of new approaches to the development of antiviral agents and vaccines as the functions of the viral genes and proteins are further elucidated. The development of techniques whereby the genes of influenza viruses can be specifically altered to investigate those functions will undoubtedly accelerate the pace at which our knowledge expands.

Animals↗
PubMed1991

Tumor infiltrating lymphocytes: the effect of bacillus Calmette Guerin on helper/suppressor-T cell ratios of treated and untreated tumors.

Copenhagen X Fischer rats bearing single and bilateral Dunning R3327 AT-3 tumors were either treated or not treated at a single site with bacillus Calmette Guerin (BCG). One week later tumors were removed, tumor infiltrating lymphocytes (TIL's) isolated, and then characterized for total-T, helper-T and suppressor-T cell subsets utilizing monoclonal antibodies. The purpose was to determine the effect of BCG on TIL's in treated as well as untreated tumors. In summary: 1) BCG treatment significantly alters TIL distributions at both injected and noninjected sites; 2) a noninjected contralateral tumor compromises the effectiveness of BCG therapy at the suppressor T cell level; 3) contralateral tumors, whether inoculated or not, have similar TIL distributions.

Animals↗
PubMed1990

Comparison of inactivated, live and recombinant DNA vaccines against influenza virus in a mouse model.

The protective efficacy of influenza hemagglutinin expressed from recombinant vaccinia virus was compared with that induced by inactivated or infectious influenza vaccines. Intraperitoneal and intranasal routes of vaccination were compared. All the vaccines except the intranasally administered, inactivated vaccine induced detectable levels of neutralizing and hemagglutination-inhibiting antibodies in the serum of mice at 28 days postvaccination. Immunization with any of the intranasally administered vaccines reduced the amount of influenza virus nucleoprotein antigen in lungs after challenge with a homologous, mouse-adapted strain of influenza virus. Intraperitoneally administered vaccines failed to provide such protection. These results indicated that the route of vaccine administration may be the most critical factor for inducing protective immunity. The results also showed that in this mouse model a recombinant DNA-based vaccine could provide protection equivalent to that provided by conventional attenuated and inactivated influenza vaccines.

Animals↗
PubMed1990

Efficacy of immunopriming prior to isolation of tumor infiltrating lymphocytes for use in adoptive immunotherapy.

Adoptive immunotherapy is dependent upon the leukocytic subsets isolated as tumor infiltrating lymphocytes (TIL) prior to in vitro expansion with interleukin-2. To favorably influence T-cell subset representation in TIL the efficacy of bacillus Calmette Guerin (BCG) and cyclophosphamide (CTX) priming was evaluated in rats bearing Dunning R3327-AT prostatic tumors. When assessed by immunohistochemistry, both agents significantly (p less than 0.001) increased helper-T representation and decreased that by suppressor-T cells. As a result helper/suppressor (H/S) T cell ratios of TIL from untreated tumors (0.73 +/- 0.11) were significantly (p less than 0.001) elevated by both BCG (1.93 +/- 0.39) and CTX (1.40 +/- 0.25). Immunopriming might enhance adoptive immunotherapy by increasing the H/S ratio of TIL prior to their culture.

Animals↗
PubMed1989

Application of immunohistologic staining to develop a malignant index to aid in distinguishing benign from malignant prostatic tissue.

The development of antisera with reactivities against intermediate filaments, differentiation antigens, and secretory products has aided in identification and characterization of tissue specimens. Such evaluations may assist pathologists in distinguishing between benign (BPH) and malignant (CAP) tissue of prostatic origin. However, attempts to employ this technique are thwarted by 1) the use of frequently incompletely characterized antisera, 2) the use of both paraffin- and frozen-sectioned materials, and 3) a lack of quantitation in the degree of antisera immunoreactivity. To overcome these shortcomings, a mathematical approach was evaluated using eight BPH and 23 CAP specimens. These were sectioned and stained using commercially prepared antisera against cytokeratin (Cyto P, Cyto M), epithelial membrane antigen (EMA), NK cells (Leu-7), prostatic acid phosphatase (PAP), and prostate specific antigen (PSA). Reactivity was quantitated on a scale of 0-5. Mean values for markers elevated in CAP (relative to BPH) were placed in the numerator; those elevated in BPH (relative to CAP) were placed in the denominator: Malignant index = PSA + EMA + Leu-7 + Cyto M/PAP + Cyto P. This malignant index was significantly greater (P less than .001) in CAP tissues than in BPH regardless of Gleason grade (3.2 +/- 0.9 vs 1.6 +/- 0.9). It was also significantly elevated (3.0 +/- 0.8; P less than .01) in nine specimens representing prostatic atypical hyperplasia. These data suggest that immunohistologic staining may be applied as an aid in distinguishing between BPH and CAP.

Diagnosis, Differential↗
PubMed1989

Cross-protection against microvariants of influenza virus type B by vaccinia viruses expressing haemagglutinins from egg- or MDCK cell-derived subpopulations of influenza virus type B/England/222/82.

B/Singapore/222/79-like influenza viruses isolated from three patients during the winter of 1981 to 1982 and cultured in either embryonated hens' eggs or MDCK cells were studied. Sequence analysis indicated that the haemagglutinin (HA) genes of the six virus preparations contained at least four distinct HA1 sequences which differed by up to six amino acids. Only one pair of viruses had amino acid differences between the egg- and MDCK cell-derived viral subpopulations and this change did not affect a glycosylation site. Mice infected with previously described recombinant vaccinia viruses expressing either the egg- or MDCK cell-derived HA of B/England/222/82 developed neutralizing antibodies against all of the 1982 type B viruses and were protected against intranasal challenge with these viruses. Therefore, in this model system, the minor sequence variation between the HAs of egg- and MDCK cell-derived influenza B/England/222/82 virus had no detectable effect on the induction of cross-protection.

Amino Acid Sequence↗
PubMed1988

Protection against virulent H5 avian influenza virus infection in chickens by an inactivated vaccine produced with recombinant vaccinia virus.

A cloned cDNA copy of the haemagglutinin (HA) gene of A/Chicken/Scotland/59 (H5N1) influenza virus has been expressed in vaccinia virus. This pox virus is poorly infectious or non-infectious for chickens. However, immunization of chickens with lysates of cell cultures infected with the recombinant vaccinia virus, that had been emulsified with adjuvant and which contained an estimated 0.5 microgram influenza HA, elicited a substantial neutralizing antibody response to influenza virus. Challenges of immunized and non-immunized adult chickens with virulent A/Chicken/Scotland/59 influenza virus showed that the immunized animals were highly protected while the non-immunized controls died. Immunized birds were also protected against infection with the recent virulent H5 avian influenza virus, A/Chicken/Pennsylvania/83 (H5N2).

Animals↗
PubMed1988

Effect of BCG upon functional and phenotypic immune markers in rats bearing the Dunning R3327 MAT-LyLu prostatic adenocarcinoma.

Rats bearing (or not bearing) the Dunning R3327 MAT-LyLu prostatic adenocarcinoma were treated with Bacillus Calmette-Guérin (BCG) and evaluated for immune competence using functional and phenotypic markers. Tumor presence significantly depressed total T and helper T cell representation along with the helper/suppressor T cell ratio. Functional immunity, measured by phytohemmagglutinin (PHA) induced blastogenesis, was also significantly depressed. When BCG was administered to non-tumor bearing animals, it had no effect upon T cell subset distributions but significantly reduced PHA induced blastogenesis. BCG similarly administered to tumor bearing animals did not alter the depressed helper/suppressor T cell ratio found in tumor bearing rats, but did significantly elevate PHA induced blastogenesis. However, these elevated levels of functional immunity in BCG treated tumor-bearing rats remained significantly below normal. These data demonstrate a poor correlation between functional and phenotypic assessments of immune capability.

Adenocarcinoma↗