Systemic arterial supply to the lungs in adults: spiral CT findings

Systemic arterial supply to the lungs can be congenital or due to acquired disease. Congenital diseases encompass bronchopulmonary sequestration and congenital pulmonary venolobar syndrome, in which the involved lung parenchyma is supplied by the aberrant systemic arteries. An anomalous systemic artery can also supply an area of otherwise normal lung parenchyma. In acquired diseases, hypertrophied normal systemic arteries supply the lungs. Hypertrophied systemic arteries include the bronchial arteries, intercostal arteries, internal mammary arteries, inferior phrenic arteries, branches of the thyrocervical trunk, branches of the hepatic arteries, and branches of the abdominal aorta. Hypertrophy of normal systemic arteries is encountered in patients with bronchiectasis, pulmonary tuberculosis, other pulmonary infections, pulmonary thromboembolism, or chronic obstructive pulmonary disease. These systemic arteries are considered to supply the lungs by means of anastomoses between bronchial and pulmonary arteries within the lung parenchyma or transpleural systemic-pulmonary artery anastomoses. In most cases, the correct diagnosis and treatment plan can be determined by identification of the systemic arteries on computed tomographic scans.

Applications of phthalimide photochemistry to macrocyclic polyether, polythioether, and polyamide synthesis

Irradiation of phthalimides which contain N-linked omega-trimethylsilylmethyl-substituted polyether, polythioether, and polysulfonamide chains results in efficient production of the corresponding macrocyclic polyether, polythioether, and polysulfonamide products. These photocyclization reactions follow sequential single electron transfer (SET)-desilylation pathways. Only in the cases of phthalimides, bearing mixed ether-thioether N-substituents, do these excited-state cyclization reactions proceed with lower degrees of regioselectivity. This is a result of competitive desilylation and alpha-to-sulfur deprotonation reactions of the zwitterionic diradical intermediates formed by initial SET.

Lipiodol solution of a lipophilic agent, (188)Re-TDD, for the treatment of liver cancer

Radiolabeled lipiodol has been used for targeting liver cancer. We developed a lipiodol solution of (188)Re-TDD (2,2,9,9-tetramethyl-4,7-diaza-1,10-decanedithiol) and investigated its feasibility for the treatment of liver cancer. The lipiodol solution of (188)Re-TDD was well-retained in the lipiodol phase in vitro. After injection through the tail veins of mice, high lung-uptake was investigated which is evidence of embolizing activity. We also found high accumulation in hepatoma after injection through the hepatic arteries of hepatoma-bearing rats. In conclusion, the lipiodol solution of (188)Re-TDD is a promising agent for liver cancer therapy.

House dust endotoxin and wheeze in the first year of life

We examined endotoxin exposure and wheezing episodes during the first year of life in a birth cohort of 499 infants with one or both parents having a history of asthma or allergy. We measured endotoxin in settled dust from the baby's bed, bedroom floor, family room, and kitchen floor within the first 3 mo after birth. The primary outcomes were any wheeze (versus no wheeze), and repeated wheeze (versus one or no report of wheeze). We found a significant univariate association of elevated endotoxin (> or = 100 EU/ mg) in family room dust with increased risk of any wheeze (Relative Risk = 1.29, 95% CI = 1.03-1.62). The association was not confounded by cockroach allergen, lower respiratory illness (croup, bronchitis, bronchiolitis, and pneumonia), smoking during pregnancy, lower birth weight, maternal asthma, presence of dog, and race/ethnicity in a multivariate model; the multivariate relative risk (RR = 1.33) was marginally significant (95% CI: 1.00-1.76, p < 0.05). In a multivariate model, controlling for the above covariates, elevated endotoxin in family room dust was significantly associated with increased risk (RR = 1.56, 95% CI = 1.03-2.38) of repeated wheeze. These results suggest that home endotoxin exposure may independently increase risk of any wheeze and repeated wheeze during the first year of life for children with a familial predisposition to asthma or allergy.

Detection of pET-vector encoded, recombinant S-tagged proteins using the monoclonal antibody ATOM-2

The 15-meric S-tag is a truncated form of the S-peptide, which builds together with the 103 amino acid large S-protein the whole ribonuclease S-protein. Its small size and excessive solubility have made the S-tag an excellent fusion partner in the production of recombinant proteins, and a large variety of applications have been reported using the S-tag as a carrier. While S-tagged proteins were mostly detected and analyzed so far by use of their affinity to S-proteins, monoclonal antibodies (MAbs) for this tag have been not available. The generation of antibodies specific for S-tagged proteins is expected to broaden the range of applications of such S-tag fused recombinant proteins, and in this context, a novel MAb termed ATOM-2 was generated that specifically binds S-tagged proteins, which have been expressed using pET-vectors. Antigen specificity of ATOM-2 was confirmed in Western blot and enzyme-linked immunoadsorbent assay analysis, and using a series of amino acid deletion mutants, the binding epitope of ATOM-2 was precisely mapped. This showed that ATOM-2 recognizes the C-terminal part of the 15-meric S-tag in context with a few residues of vector encoded sequences. The core sequence for ATOM-2 binding epitope is "His-Met-Asp-Ser-Pro-Asp-Leu-Gly-Thr," which is present in all pET-expression vectors encoding S-tag fusion proteins. Because the ATOM-2 binding region does not overlap with the S-protein binding sequence, a convenient tool is provided for the simultaneous or alternative detection, purification, and analysis of recombinant S-tagged proteins to conventional S-proteins.

Expression of MAGE-1, -2, and -3 genes in gastric carcinomas and cancer cell lines derived from Korean patients

We investigated the expression of MAGE-1, -2, and -3 genes in tissues of 51 gastric carcinomas from Korean patients and in 11 gastric cancer cell lines established in Korea using reverse transcriptase-polymerase chain reaction along with immunohistochemical analyses and DNA sequencing. Among the 51 gastric carcinomas, MAGE-1, -2, and -3 genes were expressed in 16 (31%), 22 (43%), and 17 (33%), respectively, and 31 (60%) expressed at least one of the three genes. In contrast, none of the three MAGE genes were expressed in normal sites of gastric tissue from each cancer patient. Out of 11 gastric cancer cell lines, MAGE-1, -2, and -3 genes were expressed in two (18%), five (46%), and four (36%), respectively. According to the clinicopathological analysis, the expression of any of the three MAGE genes was not significantly correlated with several clinicopathological factors except histologic types (p= 0.067). Immunohistochemical analyses identified positive staining with monoclonal antibodies 77B and 57B specifically against MAGE-1 and -3 proteins, respectively, in nuclei and cytoplasms of cells in mRNA-positive tumor tissue. These findings suggest the possibility as a target for tumor-specific immunotherapy for Korean patients.

Inactivation of farnesyltransferase and geranylgeranyltransferase I by caspase-3: cleavage of the common alpha subunit during apoptosis

Caspase plays an important role in apoptosis. We report here that farnesyltransferase/geranylgeranyltransferase (FTase/GGTase)-alpha, a common subunit of FTase (alpha/beta(FTase)) and GGTase I (alpha/beta(GGTase)), was cleaved by caspase-3 during apoptosis. FTase/GGTase-alpha (49 kDa) was cleaved to 35 kDa (p35) in the Rat-2/H-ras, W4 and Rat-1 cells treated with FTase inhibitor (LB42708), anti-Fas antibody and etoposide, respectively. This cleavage was inhibited by caspase-inhibitors (YVAD-cmk, DEVD-cho). Serial N-terminal deletions and site-directed mutagenesis showed that Asp59 of FTase/GGTase-alpha was cleaved by caspase-3. The common FTase/GGTase-alpha subunit, but not the beta subunits, of the FTase or GGTase I protein complexes purified from baculovirus-infected SF-9 cells was cleaved to be inactivated by purified caspase-3. In contrast, FTase mutant protein complex [(D(59)A)alpha/beta(FTase)] was resistant to caspase-3. Expression of either the cleavage product (60-379) or anti-sense of FTase/GGTase-alpha induced cell death in Rat-2/H-ras cells. Furthermore, expression of (D(59)A)FTase/GGTase-alpha mutant significantly desensitized cells to etoposide-induced death. Taken together, we suggest that cleavage of prenyltransferase by caspase contributes to the progression of apoptosis.

Optimal production and in vitro activity of recombinant endostatin from stably transformed Drosophila melanogaster S2 cells

Recombinant plasmids containing a complementary deoxyribonucleic acid coding mouse endostatin were transfected and stably expressed in Drosophila melanogaster Schneider 2 (S2) cells. Stably transformed polyclonal cell populations expressing recombinant endostatin were isolated after 4 wk of selection with hygromycin B. Recombinant endostatin expressed in the stably transformed S2 cells under the influence of the Drosophila BiP protein signal sequence was secreted into the medium. Recombinant endostatin was also purified to homogeneity using a simple one-step Ni2+ affinity fractionation method. Purified recombinant endostatin inhibited endothelial cell proliferation in a dose-dependent manner. The concentration at maximum inhibition for recombinant endostatin was approximately 1.8 microg/ml. The stably transformed S2 cells produced 18 mg recombinant endostatin/L 7 d after induction with 5 microM CdCl2. Sodium butyrate supplementation (2.5 mM) increased recombinant endostatin production by 17%. These findings demonstrate optimal production and in vitro activity of recombinant endostatin from stably transformed D. melanogaster S2 cells.

Human in-vivo 31P MR spectroscopy of benign and malignant breast tumors

OBJECTIVE

To assess the potential clinical utility of in-vivo 31P magnetic resonance spectroscopy (MRS) in patients with various malignant and benign breast lesions.

MATERIALS AND METHODS

Seventeen patients with untreated primary malignant breast lesions (group I), eight patients with untreated benign breast lesions (group II) and seven normal breasts (group III) were included in this study. In-vivo 31P MRS was performed using a 1.5 Tesla MR scanner. Because of the characteristics of the coil, the volume of the tumor had to exceed 12 cc (3 x 2 x 2 cm), with a superoinferior diameter at least 3 cm. Mean and standard deviations of each metabolite were calculated and metabolite ratios, such as PME/PCr, PDE/PCr, T-ATP/PCr and PCr/T-ATP were calculated and statistically analyzed.

RESULTS

Significant differences in PME were noted between groups I and III (p=0.0213), and between groups II and III (p=0.0213). The metabolite ratios which showed significant differences were PME/PCr (between groups II and III) (p=0.0201), PDE/PCr (between groups I and III, and between groups II and III) (p=0.0172), T-ATP/PCr (between groups II and III) (p=0.0287), and PCr/T-ATP (between groups II and III) (p=0.0287). There were no significant parameters between groups I and II.

CONCLUSION

In-vivo 31P MRS is not helpful for establishing a differential diagnosis between benign and malignant breast lesions, at least with relatively large lesions greater than 3 cm in one or more dimensions.

Intramitochondrial pyruvate attenuates hydrogen peroxide-induced apoptosis in bovine pulmonary artery endothelium

In the hydrogen peroxide (H2O2) apoptosis model of the murine thymocyte, redox reactant and antioxidant pyruvate prevents programmed cell death. We tested the hypothesis that such protection was mediated, at least in part, via pyruvate handling by mitochondrial metabolism. Cultured bovine pulmonary artery endothelial cells were incubated for 30 min with 0.5 mM H2O2 in the absence and presence of 0.5 mM alpha-cyano-3-hydroxycinnamate, as a selective inhibitor of the mitochondrial pyruvate transporter. In controls H2O2 decreased cell viability by 30% within 24 h; this was associated with apoptosis-like bodies, nuclear condensation, and biochemical DNA damage consistent with programmed cell death. Pyruvate (0.1-20 mM) enhanced cell viability in a dose-dependent manner, with > or = 85% viable cells at > or = 3 mM and no DNA laddering, no positive nick-end labeling (TUNEL), and no detectable Annexin V or propidium iodide staining. In contrast, using > or = 5 mM L-lactate as a cytosolic reductant or acetate as a redox-neutral substrate, cell death increased to approximately 40%, which was associated with intense DNA laddering, positive TUNEL and Hoechst 33258 assays. Alpha-cyano-3-hydroxycinnamate alone did not significantly decrease endothelial viability but reduced viability from 85+/-3 to 71+/-4% (p = 0.023) in presence of 3 mM pyruvate plus H2O2; pathological cell morphology and DNA laddering under the same conditions suggested loss of pyruvate protection against apoptosis. Since alpha-cyano-3-hydroxycinnamate re-distributed medium pyruvate and L-lactate consistent with selective blockade of pyruvate uptake into the mitochondria, the findings support the hypothesis that pyruvate protection against H2O2 apoptosis is mediated in part via the mitochondrial matrix compartment. Possible mediators include anti-apoptotic bcl-2 and/or products of mitochondrial pyruvate metabolism such as citrate that affect metabolic regulation and anti-oxidant status in the cytoplasm.

Retinoic acid (RA) receptor transcriptional activation correlates with inhibition of 12-O-tetradecanoylphorbol-13-acetate-induced ornithine decarboxylase (ODC) activity by retinoids: a potential role for trans-RA-induced ZBP-89 in ODC inhibition

Evaluation of retinoic acid receptor (RAR) subtype-selective alpha and gamma agonists and antagonists and a retinoid X receptor (RXR) class-selective agonist for efficacy at inhibiting both induction of ornithine decarboxylase (ODC) by the tumor promoter 12-O-tetradecanoylphorbol-13-acetate (TPA) in mouse epidermis and rat tracheal epithelial cells and the appearance of papillomas in mouse epidermis treated in the 2-stage tumor initiation-promotion model indicated that (i) RXR class-selective transcriptional agonists, such as MM11246, were not involved in ODC inhibition; (ii) RAR-selective agonists that induce gene transcription from RA-responsive elements (RAREs) were active at low concentrations; (iii) RAR-selective antagonists that bind RARs and inhibit AP-1 activation on the collagenase promoter but do not activate RAREs to induce gene transcription were less effective inhibitors; and (iv) RARgamma-selective retinoid agonists were more effective inhibitors of TPA-induced ODC activity than RARalpha-selective agonists. These results suggest that RARE activation has a more important role in inhibition of ODC activity than RXR activation or AP-1 inhibition and that RARgamma-selective agonists would be the most useful inhibitors of epithelial cell proliferation induced by tumor promoters. The natural retinoid all-trans-RA induced expression of transcription factor ZBP-89, which represses activation of the GC box in the ODC promoter by the transcription factor Sp1.

A novel nucleolar G-protein conserved in eukaryotes

We describe here a novel, evolutionarily conserved set of predicted G-proteins. The founding member of this family, TbNOG1, was identified in a two-hybrid screen as a protein that interacts with NOPP44/46, a nucleolar phosphoprotein of Trypanosoma brucei. The biological relevance of the interaction was verified by co-localization and co-immunoprecipitation. TbNOG1 localized to the trypanosome nucleolus and interacted with domains of NOPP44/46 that are found in several other nucleolar proteins. Genes encoding proteins highly related to TbNOG1 are present in yeast and metazoa, and related G domains are found in bacteria. We show that NOG1 proteins in humans and Saccharomyces cerevisae are also nucleolar. The S. cerevisae NOG1 gene is essential for cell viability, and mutations in the predicted G motifs abrogate function. Together these data suggest that NOG1 may play an important role in nucleolar functions. The GTP-binding region of TbNOG1 is similar to those of Obg and DRG proteins, which, together with NOG, form a newly recognized family of G-proteins, herein named ODN. The ODN family differs significantly from other G-protein families, and shows several diagnostic sequence characteristics. All organisms appear to possess an ODN gene, pointing to the biological significance of this family of G-proteins.

Identification, expression, and nuclear location of murine Mage-b2 protein, a tumor-associated antigen

MAGE-1, which was originally identified by reacting with cytolytic T lymphocytes derived from the blood of melanoma patients, is a member of a gene family consisting of 17 structurally related genes. The MAGE genes are expressed only in the testis among normal tissues and in a number of human tumors of various histological types. Murine MAGE (also called SMAGE or Mage) genes were found in a study aimed at detecting mouse genes homologous to human MAGE genes. However, the biological functions of MAGE and Mage are currently unknown. To understand the biological functions of Mage, in the present study a recombinant SMAGE2 (Mage-b2) protein of 43 kDa was produced and monoclonal antibodies reactive with Mage-b2 protein were generated. One monoclonal antibody, smpG4A, specifically recognized a 43 kDa protein in lysates of Mage-b2 mRNA-positive sarcoma cells and of the testis. Immunohistochemistry showed that Mage-b2 is located in the nucleus of Mage-b2 mRNA-positive sarcoma cells. These results should contribute to understanding the biological functions of Mage.

Downregulation of MHC class II expression by oxidant-induced apoptosis in EBV-transformed B-cells

The expression of MHC class II molecules is actively regulated upon various cellular stimuli. Since apoptosis is an inducible cellular process, it was asked whether cells undergoing apoptosis would also modulate their expression of class II molecules. Using an EBV-transformed B-cell line, the cell surface expression of HLA-DR molecules was analyzed by fluorescence-activated flow cytometry on normal and oxidant-treated apoptotic cells. A rapid and continuous decrease in HLA-DR expression was observed in apoptotic cells. RNA analysis and semiquantitative RT-PCR of cytoplasmic beta-actin mRNA showed that apoptotic cells contain partially degraded RNA and much lower amounts of beta-actin mRNA. Nevertheless, when compared after normalization of intact mRNA amounts, the HLA-DRB mRNA signals were of similar strength in normal and apoptotic cells as determined by semiquantitative RT-PCR. Thus, the decrease in the number of class II molecules during apoptosis underlies no specific program for downregulation of HLA-DRB mRNA transcription but is due to a nonspecific degradation of RNA molecules accompanied by cell death.

Dammarane derivatives protect cultured rat cortical cells from glutamate-induced neurotoxicity

We previously reported that ginsenosides Rb1 and Rg3, dammarane glycosides, of Panax ginseng C. A. Meyer (Araliaceae), significantly attenuated glutamate-induced neurotoxicity in primary cultures of rat cortical cells. To seek more potent neuroprotective compounds, we attempted to modify the chemical structure of dammarane glycosides and obtained six derivatives, MA-11, PT-11, PT-111, POA-101, POA-111 and N-001. The neuroprotective activity of these dammarane derivatives were evaluated employing primary cultures of rat corticoid cells. The glutamate-induced neuronal cell damage was significantly reduced by a pre-treatment with protopanaxadiol, MA-11 or PT-11 at concentrations ranging from 100 nM to 10 microM. Both MA-11 and PT-11, preserved the levels of catalase and inhibited decreases in glutathione reductase in glutamate-injured cells. Furthermore, the dammarane derivatives reduced the content of intracellular peroxide in glutamate-intoxicated cells. Finally, they inhibited the formation of malondialdehyde, a compound produced during lipid peroxidation, in glutamate-insulted cells. These results show that the dammarane derivatives, MA-11 and PT-11, exert significant neuroprotective effects on cultured cortical cells by a mechanism seemingly distinct from that afforded by ginsenosides Rb1 and Rg3. As such, the dammarane derivatives may be efficacious in protecting neurons from oxidative damage caused by exposure to excess glutamate.

Differential validity of the Defense Mechanism Manual for the TAT between Asian Americans and Whites. Thematic Apperception Test

Thematic Apperception Test (Murray, 1943) responses of 69 Asian American (hereafter, Asian) and 83 White students were coded for defenses according to the Defense Mechanism Manual (Cramer, 1991b) and studied for differential validity in predicting paper-and-pencil measures of relevant constructs. Three tests for differential validity were used: (a) differences between validity coefficients, (b) interactions between predictor and ethnicity in criterion prediction, and (c) differences between groups in mean prediction errors using a common regression equation. Modest differential validity was found. It was surprising that the DMM scales were slightly stronger predictors of their criteria among Asians than among Whites and when a common predictor was used, desirable criteria were overpredicted for Asians, whereas undesirable ones were overpredicted for Whites. The results were not affected by acculturation level or English vocabulary among the Asians.

Efficiency of promoter and cell line in high-level expression of erythropoietin

Efficiency of viral promoters and various cell lines in directing high-level expression of human erythropoietin (Epo) was investigated. To investigate the effects of various viral promoters and cell lines on the Epo expression level, genomic Epo with the 5' and 3' untranslated regions (UTRs) deleted was cloned next to the simian virus 40 early promoter, cytomegalovirus early promoter or SRalpha promoter. These expression vectors were transfected into COS-7, BHK-21 and Chinese hamster ovary (CHO)/dhfr(-) cells, respectively. The COS-7 cells transfected with the vector containing the SRalpha promoter showed the highest expression level ( approximately 103 IU/ml) at 72 h post-transfection. For the development of Epo-producing stable cell lines, BHK-21 and CHO/dhfr(-) cells transfected with the 5',3'-UTR-deleted genomic Epo under the control of the SRalpha promoter were cultured with media containing zeocin. Several clones of zeocin-resistant BHK-21 and CHO/dhfr(-) cells were cultured in the presence of methotrexate (MTX). A BHK-21 clone selected in the presence of 500 nM MTX expressed and secreted approximately 490 IU/ml Epo into the medium. A CHO/dhfr(-) clone selected in the presence of 20 nM MTX expressed and secreted approximately 45 IU/ml Epo into the medium. Southern-blot analysis indicated that enhancement of Epo expression in the MTX-resistant stable cells might be related to the amplification of gene copy number.

In vitro binding analysis of hepatitis B virus preS-derived putative helper T-cell epitopes to MHC class II molecules using stable HLA-DRB1*0405/DRA*0101 transfected cells

In designing epitope-based vaccines, the inclusion of a helper T-lymphocyte (HTL) epitope is necessary to elicit both humoral and cellular immune responses. Whereas the preS region of the hepatitis B virus (HBV) surface antigen is well-known to raise protective immunity, the epitopes for activating HTLs are poorly characterized. In an attempt to identify such epitopes, the HBV-preS region was screened for peptide sequences with HLA-DR4 binding motifs, and putative HTL candidate peptides were synthesized in a biotinylated form. Using L929 mouse fibroblasts stably transfected with HLA-DRB1*0405 and HLA-DRA*0101 cDNA, specific binding of the peptides was then detected using fluorescence-conjugated streptavidin. The cell-surface expression of HLA-DR molecules on transfectants was confirmed by confocal microscopy, and quantitative analysis of candidate peptide binding was performed by fluorescence activated cell sorting. Among eight preS-derived peptides, three candidate peptides-namely preS1(23-33), preS1(62-72), and preS1(76-86)-showed good binding characteristics to HLA-DR4 molecules, among which the preS1(23-33) epitope was regarded as the most promising HTL epitope. Further studies with these candidate HTL stimulatory peptides will show their ability to activate the human immune system against HBV.

Steaming of ginseng at high temperature enhances biological activity

The present study was performed to evaluate the effect of steaming ginseng at a temperature over 100 degrees C on its chemical constituents and biological activities. Raw ginseng was steamed at 100, 110, and 120 degrees C for 2 h using an autoclave. The ginseng steamed at 120 degrees C was more potent in its ability to induce endothelium-dependent relaxation. Steaming the raw ginseng at 120 degrees C also remarkably increased the radical-scavenging activity. Ginsenosides F(4), Rg(3), and Rg(5), which were not present in raw ginseng, were produced after steaming. Ginsenosides Rg(3) and Rg(5) were the most abundant ginsenosides in the ginseng steamed at 120 degrees C, accounting for 39% and 19% of all ginsenosides, respectively.

Gene expression profile and identification of differentially expressed transcripts during human intrathymic T-cell development by cDNA sequencing analysis

The development of immature thymocytes to mature T-lymphocytes is a central process for establishing a functional immune system. The gene regulatory events involved in this process are of outstanding interest in understanding the generation of the T-cell repertoire as well as the differentiation of lineage-specific cells, such as CD4(+) helper T-cells or CD8(+) cytotoxic T-lymphocytes. While some essential genes involved in lineage decision and thymocyte differentiation have been already identified, the exact regulatory mechanisms and differential gene expressions are still unknown. The present study was performed to analyze the gene expression profile during T-cell development, in particular, during the differentiation of immature thymocytes into CD4(+) mature T-cells by analyses of expressed sequence tags (ESTs), and to elucidate novel human genes involved in this process. Based on distinct developmental stages, three PCR-based cDNA libraries from immature CD3(-),4(-),8(-) triple-negative, CD4(+),8(+) double-positive, and mature CD4(+),8(-) single-positive thymocytes were constructed. A total of 1477 randomly selected clones were analyzed by automated single-pass sequencing, and the assembly of ESTs resulted in 1027 different species of contig sequences. Among them, 392 contig sequences were matched to known genes, and several novel transcripts were discovered. The matched clones were classified into seven categories according to their functional aspects, and the gene expression profiles of the three thymocyte subsets were compared. The information obtained in current study will serve as a valuable resource for elucidating the molecular mechanism of intrathymic T-cell development.

Longitudinal study of dust and airborne endotoxin in the home

To characterize the seasonal variability of endotoxin levels, we measured endotoxin in dust from the bed, bedroom floor, and kitchen floor in 20 homes, and in air from the bedroom in 15 of the homes. All homes were located in the greater Boston, Massachusetts, area and were sampled each month from April 1995 to June 1996. Outdoor air was collected at two locations. We found greater within-home than between-home variance for bedroom floor, kitchen floor, and airborne endotoxin. However, the reverse was true for bed dust endotoxin. Thus, studies using single measurements of dust endotoxin are most likely to reliably distinguish between homes if bed dust is sampled. Dust endotoxin levels were not significantly associated with airborne endotoxin. Airborne endotoxin was significantly (p = 0. 04) and positively associated with absolute humidity in a mixed-effect model adjusting for a random home effect and fixed effect of sampling month and home characteristics. This finding implies that indoor humidity may be an important factor controlling endotoxin exposure. We found a significant (p < 0.05) seasonal effect in kitchen floor dust (spring > fall) and bedroom airborne endotoxin (spring > winter), but not in the other indoor samples. We found significant seasonal pattern in outdoor airborne endotoxin (summer > winter).

Microsatellite alteration in histologically normal lung tissue of patients with non-small cell lung cancer

Microsatellite alteration (MSA) has been observed in a fraction of non-small cell lung cancer (NSCLC). Most prior studies regarding MSA in lung cancer have usually used adjacent non-malignant lung tissues as a source of constitutional DNA. However, these normal tissues might have genetic alterations because the entire field of bronchial tree is exposed to the same carcinogenic insult. The aim of this study was to search if MSA is present in the histologically normal lung tissue of patients with NSCLC. Tumor and corresponding normal lung tissue specimens were obtained from 20 patients with NSCLC. Normal lung tissue specimens were obtained from either the opposite end of resected surgical samples or as distant from the tumor as possible. They were examined histopathologically and confirmed as normal by H-E stain. Patients' peripheral lymphocytes were used as the source for the normal DNA. Sixteen markers on 3p and 9p (nine and seven markers, respectively) were used. MSA was detected in seven of 20 (35%) histologically normal lung tissue specimens at a frequency similar to that observed in tumor tissue (eight of 20, 40%). Five cases showed MSA in both normal lung tissue and the corresponding tumor. In these five cases, MSA in normal lung tissue was detected at the same microsatellite markers which MSA was detected in the corresponding tumor. The number and size of novel bands in normal lung tissue was identical to that in tumor tissue except in one case. In which case, the same pattern of MSA was found in both normal lung tissue and corresponding tumor tissue at two markers. However, at one marker, while one identical novel band was detected in normal lung tissue and corresponding tumor tissue, another novel band was found only in tumor tissue. In two of 12 patients whose tumor was negative for the presence of MSA, MSA was detected in normal lung tissue. These results indicate that genetic alterations are widely distributed in the lung tissue of patients with lung cancer and provide considerable support for the field cancerization theory. Screening for MSA in resected normal lung tissue might be a new method to identify patients at high risk for developing second primary lung cancers.