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Biomedical subjects

L Flaherty

Publications and source records attributed to L Flaherty.

At least 91 records · Page 5Linked to original sources
PubMed1991

5-Fluorouracil, etoposide, and cisplatin in the management of metastatic non-small cell lung cancer.

Encouraging response rates have been reported in Stage III non-small cell lung cancer when 5-fluorouracil (5-FU), etoposide (VP-16), and cisplatin (FED) have been combined with radiation therapy (RT) or RT and surgery. The current study evaluated the effectiveness of FED chemotherapy in 32 patients with metastatic non-small cell lung cancer. Treatment consisted of 5-FU (800 mg/m2/d) on days 1 to 4 by continuous infusion, intravenous (IV) VP-16 (60 mg/m2) over 1 hour on days 1 to 4, and IV cisplatin (60 mg/m2) over 1 hour on day 1. Treatment cycles were repeated every 28 days as toxicity permitted. Partial responses occurred in 7 of 32 patients (22%; 95% confidence limit [CL] 0.09, 0.40), including 6 of 19 patients (32%) with performance status of 0 or 1, and 1 of 13 patients (8%) with performance status of 2 or 3. The median response duration was 5.0 months. Although toxicity was modest and consisted of primarily hematologic and gastrointestinal side effects, this combination does not appear to provide an advantage over other cisplatin combinations in Stage IV non-small cell lung cancer.

Adult↗
PubMed1991

Nonconventional (TL-encoded) major histocompatibility complex molecules present processed viral antigen to cytotoxic T lymphocytes.

A large number of class I-like genes are located distal to the K and D regions of the murine major histocompatibility complex (MHC) within the Q and TL region. The function of the molecules encoded within this region is obscure since unlike conventional MHC gene products, these molecules have not been reported to present processed environmental antigens to T cells. In the present report, we demonstrate that a peptide corresponding to processed influenza virus hemagglutinin can be recognized by CD8+ T cell receptor alpha/beta-positive cytotoxic T lymphocytes (CTL) in association with a MHC class I-like product encoded within the TL region. Thus, nonconventional class I MHC molecules can bind and present processed environmental antigens, and TCR-alpha/beta CTL directed to such peptide MHC complexes are represented in the mature T cell pool. Our data imply that Q/TL region products may be charged by peptides generated through an antigen processing and presentation pathway distinct from the pathway used by conventional MHC molecules and not normally available to environmental antigens.

Amino Acid Sequence↗
PubMed1991

Expression and regulation of Q8b in a transfected cell line.

RNase protection experiments showed that Q8b was actively transcribed in a stably transfected cell line. Moreover, Q8b responded to interferon-gamma (IFN-gamma) treatment with increased levels of mRNA expression. Thus Q8b demonstrates a regulatory response to IFN-gamma characteristic of many other class I genes. Cell surface expression of a Q8b product could also be detected by flow cytometric analysis with the Qa-2-specific monoclonal antibody D3.262. The expression of the Q8b cell surface product increased only slightly after cells were treated with IFN-gamma. The Q8b cell surface product was not sensitive to cleavage by phosphatidylinositol-phospholipase C. These results suggest that the Q8b product, unlike the predominant forms of Qa-2-bearing molecules, is not anchored via phosphatidylinositol to the cell membrane. These results also suggest that Q8b has the potential to contribute to the Qa-2 phenotype in vivo.

Animals↗
PubMed1991

State-university collaboration in psychiatry: the Pew Memorial Trust Program.

This contribution summarizes the background leading up to the goals of and the experience gained from a major national initiative to expand and improve collaborative activities between state departments of mental health and university departments of psychiatry through regional conferences, national workshops, ongoing consultations, and awards. It details the problems of the public system and how successful collaborative efforts have improved the situation, cites the role of one such a program (in Maryland), recounts the process of holding a national invitational conference and the subsequent "Call to Action," and summarizes what the Pew Project is intended to do and how the project is progressing.

Academies and Institutes↗
PubMed1991

Molecular organization of the D-Qa region of t-haplotypes suggests that recombination is an important mechanism for generating genetic diversity of the major histocompatibility complex.

We have determined the molecular maps of the H-2D and Qa regions of the t-complex haplotypes t12 and tw5 by chromosomal walking. Analysis with class I probes and other probes unique to the H-2D:Qa subregion indicates that the class I gene organization of t12 is: D1-D2-Q1-Q2-Q3-Qx-Q4-Q5-Q10, while that of tw5 is: D1-D2-Q1-Q2-Q4-Q5-Q10. Thus, the absence of the Q6-Q9 genes suggested previously in t-haplotypes was confirmed. A comparison of the molecular maps of the t12 and tw5 chromosomes revealed an extremely mosaic pattern of diversity: The regions between D1 and D2, and between Q4 and Q10, are very similar in both chromosomes. However, their Q1 to Q3 regions are strikingly different. Further comparisons of wild-type chromosomes and additional t-haplotypes by molecular mapping and genomic Southern blot hybridization with probes to the Q1-Q3 region showed a high level of polymorphism among both wild-type chromosomes and among t-haplotypes. The characteristics of the polymorphisms suggest that recombination may play an important role in generating this genetic diversity. Furthermore, recombination between wild-type and t-haplotype chromosomes may be involved.

Animals↗
PubMed1991

Sequential dacarbazine/cisplatin and interleukin-2 in metastatic melanoma: immunological effects of therapy.

Thirteen previously untreated patients with metastatic melanoma entered into a phase II chemo-immunotherapy trial were monitored immunologically during treatment. Treatment consisted of dacarbazine (DTIC) 750 mg/m2 and cisplatin 100 mg/m2 on day 1 followed by interleukin-2 (IL-2) 4 x 10(6) U/m2 by daily intravenous bolus on days 12-16 and 19-23. Cycles were repeated every 28 days. On days 1 (pretreatment), 12, 16, and 23 of each cycle, lymphokine-activated killer (LAK) cell and natural killer cell activity as well as total lymphocyte count and CD3, CD4, CD8, and CD56 lymphocyte subsets were analyzed. Despite pretreatment with full-dose cytotoxic chemotherapy, all patients were able to respond immunologically to IL-2. Spontaneous LAK cell activity was generated by the end of each course of IL-2 administration and persisted for at least 5 days thereafter. Lymphocytosis was maximum at 5 days after IL-2 administration and included increased numbers of all measured lymphocyte subsets. IL-2 administration caused a relative increase in CD56+ cells and a relative decrease in CD3+ cells. There was a direct correlation between the increase in LAK cell activity and the increase in CD56+ lymphocytes. Antitumor responses occurred in five patients but these responses did not correlate with any of the measured changes in LAK activity or lymphocyte subsets. DTIC and cisplatin administered in this schedule does not abrogate the immunological effects of IL-2.

Adolescent↗
PubMed1991

Minor splenic injuries: associated injuries and transfusion requirements.

To address criticisms of nonoperative management of splenic injury, we hypothesized that (1) patients with minor splenic injuries have a lower risk of associated visceral damage than patients with splenic injuries in general, and (2) exploration of these patients does not decrease their blood requirements. We reviewed charts of 182 patients who suffered blunt splenic trauma between 1983 and 1988. Sixty-seven sustained minor injuries, defined as requiring no therapy or responding to topical hemostatic agents. Twenty-three were initially managed nonoperatively, with three subsequently explored surgically for falling hematocrit; no associated injury requiring therapy was found. The median transfusion requirement in these 23 patients was 2 units. Forty-four were immediately explored, 11 for readily diagnosed injuries mandating laparotomy. The other 33 were explored for hemoperitoneum. One had an unsuspected bowel injury. The median blood requirement in these 33 was 2.5 units. We conclude that patients with minor splenic injuries who have no other indication for laparotomy have a very low incidence of associated significant abdominal injury. Their transfusion requirements are also not reduced by exploration.

Abdominal Injuries↗
PubMed1990

Phase II study of deoxydoxorubicin in previously untreated metastatic breast cancer.

With the objective of identifying new chemotherapeutic agents active against breast cancer, we administered the phase II agent deoxydoxorubicin (DxDx) to 25 patients who had received no prior chemotherapy for their metastatic breast cancer. A dose of 30-35 mg/M2 given at 3 week intervals resulted in a response rate of 12%. The patients were subsequently treated with a combination of 5-fluorouracil, methotrexate, vincristine, cyclophosphamide, and prednisone. A response rate of 38% was achieved with this combination as second line therapy. Toxicity of DxDx was predominantly hematopoietic. One patient developed congestive heart failure. Median survival from onset of treatment with DxDx was 39 weeks. DxDx appears to be minimally active against metastatic breast cancer. Whether the administration of phase II agents as first line therapy offers an advantage in the overall management of metastatic cancer, needs further evaluation.

Adult↗
PubMed1990

Genetic polymorphisms of Q region genes from wild-derived mice: implications for Q region evolution.

Both serological and DNA sequence analyses were performed to determine the extent of genetic polymorphism in Q region genes. A panel of Qa-2-specific monoclonal antibodies (mAbs) was tested on 35 wild-derived and inbred mouse strains. Members of this reagent panel recognize multiple and distinct epitopes on the Qa-2-bearing molecule(s). Although quantitative variations in Qa-2 levels were observed, no structural polymorphisms were detected. All strains were either entirely positive or entirely negative with the complete set of reagents. Moreover, cell surface Qa-2 expression was not significantly affected by differences in age or sex of the mouse or cell cycle status. To confirm this apparent lack of genetic polymorphism, the polymerase chain reaction (PCR) technique was used to amplify a portion of the 3' end of the Q region genes, Q4 to Q9, from several independent wild-derived strains of mice. Sequence analysis of the amplified material revealed very little evidence of nucleotide divergence. All strains tested had a Q even DNA sequence identical to that of Q6/Q8 in the B10 strain. Likewise, all tested strains had a Q odd DNA sequence identical to Q7/Q9 in the B10 strain. Two strains showed additional Q even sequences, while all strains tested possessed additional Q odd sequences. The observed lack of polymorphism suggests that the Q genes have evolved in a different manner from H-2K and H-2D. Moreover, duplications of these genes appear to have arisen prior to nucleotide sequence divergence.

Aging↗
PubMed1990

Biochemical differences in Qa-2 antigens expressed by Qa-2+,6+ and Qa-2+,6- strains. Evidence for differential expression of the Q7 and Q9 genes.

Cell surface forms of Qa-6 class I molecules are biochemically indistinguishable from Qa-2 although Qa-6 maps telomeric to Qa-2 with the recombinant strain B6.K2. Analysis of appropriate F1 strains did not demonstrate the presence of a trans acting factor that could modify the Qa-2 molecule to produce the Qa-6 determinant. Also, neither a neighboring cell surface molecule nor oligosaccharides were found to block the recognition of the Qa-6 determinant in Qa-2+,6- strains. The 2-D gel profiles of neuraminidase or endoglycosidase treated anti-Qa-2 immunoprecipitates from lysates of cell surface iodinated Qa-2+,6+ strains revealed an additional basic polypeptide which was absent from that of Qa-2+,6- strains. Thus, differential sialylation/glycosylation of Qa-2 molecules masks detection of Qa-2 antigen heterogeneity when cell surface forms are analyzed. Qa-6+ phenotype associated polypeptides were also found at various stages of post-translational processing in cells metabolically labeled in the presence and absence of tunicamycin. Northern analyses using Q7 and Q9 specific oligonucleotide probes revealed appropriate sized transcripts for both genes in the Qa-2+,6+ strain B6 but only Q9 in the Qa-2+,6- strain B6.K2. These data demonstrate that there is structural heterogeneity in Qa-2 antigens expressed by Qa-2+,6+ and Qa-2+,6- strains which results from differential expression of the Q7 and Q9 genes.

Animals↗
PubMed1990

A phase I trial of recombinant interleukin-2 combined with recombinant interferon-gamma in patients with cancer.

Twenty-six patients with metastatic cancer were entered into a phase I trial of concurrent recombinant interleukin-2 (IL-2) and recombinant interferon-gamma (IFN-gamma). IL-2 was administered as a continuous intravenous infusion for 5 days. IFN-gamma was administered by a daily intramuscular (IM) injection during the 5 days of IL-2 administration. Treatment was repeated twice after 9-day rest periods. After a 2-week rest, patients without evidence of tumor progression were retreated. Natural killer (NK)- and lymphokine-activated killer (LAK)-cell activity were assayed in each patient before treatment, on day 1, and on day 5 of each cycle. Constitutional symptoms occurred in most patients but were not dose-limiting. Other toxicities included hypotension responsive to fluids, transient elevations in liver function tests, erythema/pruritus, eosinophilia, and transient leukopenia/thrombocytopenia. The maximum-tolerated dose (MTD) of the combination was 1 x 10(6) U/m2/d of IL-2 combined with 0.50 mg/m2/d of IFN-gamma. The dose-limiting toxicity was pulmonary manifesting as rales and shortness of breath. The dose of the combination that resulted in the optimal generation of in vivo LAK-cell activity was a dose of at least 0.25 mg/m2/d of IFN-gamma combined with 1 x 10(6) U/m2/d of IL-2. Objective clinical responses were seen in five of 26 patients. These included a partial response of 2 months duration in a patient with non-Hodgkin's lymphoma (NHL), mixed responses in a patient with NHL and two patients with renal cell carcinoma (RCC), and an ongoing assessable response in a patient with bone metastases from RCC. The recommended dose for phase II trials of this combination is 0.50 mg/m2 of IFN-gamma and 1 x 10(6) U of IL-2.

Adolescent↗
PubMed1989

Genetics and expression of the Q6 and Q8 genes. An LTR-like sequence in the 3' untranslated region.

A unique 2.2-kb mRNA is transcribed from the Q6 and Q8 genes of the mouse major histocompatibility complex. RNase protection experiments and DNA sequence analysis have mapped the 3' terminus to a site located 1110 bp downstream from exon 8. Comparison of the 3' sequence of Q8 to that of Q7 revealed that the two genes diverge from one another at a point located 200 bp into the untranslated domain. This finding explains the increased size of the transcript. RNase protection experiments involving twelve different strains of mice have revealed few sequence polymorphisms. A tissue distribution of the 2.2-kb transcript in B6 mice revealed that the highest quantities of message were present in the spleen with decreasingly lower amounts in the thymus, liver, kidney, testis, and brain. The H-2r haplotype appeared novel; it is phenotypically Qa-2-, yet expressed a 2.2-kb transcript which hybridizes to a Q8 probe. A comparison of a Qa-2hi expressor, B6, and a Qa-2low expressor, BALB/cFla, has established that these quantitative cell surface differences are reflected in mRNA differences. A homology search of the Genbank database has revealed that the 3' portion of Q8 contains extensive homology to a retrovirus-like long terminal repeat sequence that is characteristic of an embryonic-specific transposon (ETn).

Alleles↗
PubMed1988

Characterization of a new subfamily of class I genes in the H-2 complex of the mouse.

A previously undescribed subfamily of mouse class I MHC genes, consisting of two to three members, has been identified. The structure and organization of one of these, Mb1, has been determined. Mb1 consists of five exons with open reading frames and potentially encodes a class I-like transmembrane protein. In the genome, Mb1 is linked to the H-2 complex, mapping telomeric to Qa. However, this gene has low (ca. 60%) nucleotide identity with other class I sequences and is no more related to mouse class I genes than to class I genes from other species. Mb1 transcripts have not been found in a variety of adult tissues or cell lines, suggesting that, if Mb1 is expressed, its expression is highly regulated. From DNA sequence identity and intron-exon organization, Mb1 appears to be a primordial gene which antedates mouse speciation and which has evolved independently of the rest of the class I gene family. Examination of various species of wild mice demonstrates the presence of a discrete Mb1 subfamily over long evolutionary periods of time.

Amino Acid Sequence↗