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Biomedical subjects

S Goswami

Publications and source records attributed to S Goswami.

At least 37 records · Page 2Linked to original sources

Pharmacologic characterization of latex extracts by isolated guinea pig tracheal tissue.

Latex manufacturing workers are exposed to a heterogeneous aerosol of organic compounds. Previous studies of latex workers involved in glove production indicate that these individuals are at risk of developing respiratory symptoms and impaired lung function. The effect of latex extracts on isolated guinea pig tracheal smooth muscles was studied using latex water-soluble extracts obtained at different stages of the industrial process. Latex extracts were prepared as a 1:10 (w/v) solution. Dose-related contractions of nonsensitized guinea pig trachea were demonstrated using two latex extracts (latex 1 and latex 2). Latex 1 was prepared from the native latex and latex 2 from a processed form of latex which was relatively free of soluble proteins. Pharmacologic studies were performed by pretreating guinea pig tracheal tissue with drugs known to modulate smooth muscle contraction: atropine, indomethacin, pyrilamine, nordihydroguaiacetic acid, acivicin, trimethobenzoic acid and capsaicin. Constrictor effects of the dust extracts were inhibited by a wide variety of these agents. Atropine consistently and strikingly reduced the contractile effects of these extracts. This observation may suggest an interaction of the extracts with parasympathetic nerves or more directly with muscarinic receptors. Inhibition of contraction by blocking other mediators was less effective and varied with the dust extract. Pretreatment with capsaicin did not change the constrictor effects of latex 1 but enhanced the effects of latex 2. Depletion of neuropeptides, however, did not reduce the constrictor effect. We suggest that latex extracts cause dose-related airway smooth muscle constriction by nonimmunological mechanisms involving a variety of airway mediators and possibly cholinergic receptors. This effect is not dependent on the presensitization of guinea pigs.

Animals↗

Immunohistochemical evaluation of hepatoblastomas with use of the hepatocyte-specific marker, hepatocyte paraffin 1, and the polyclonal anti-carcinoembryonic antigen.

The distinction of hepatoblastoma, especially the embryonal type, from other small, round-cell tumors of childhood can sometimes be difficult. Polyclonal anticarcinoembryonic antigen (pCEA) and Hepatocyte Paraffin 1 (Hep Par 1) are immunohistochemical markers that are useful in the diagnosis of hepatocellular carcinomas. We immunohistochemically studied pCEA, monoclonal CEA (mCEA), and Hep Par 1 on 12 hepatoblastomas (3 fetal type, 2 embryonal type, and 7 mixed epithelial type). In addition, we studied the expression of Hep Par 1 on 27 other selected childhood tumors, including 1 hepatocellular carcinoma, 5 germ-cell tumors, 4 peripheral neuroectodermal tumors/Ewing's sarcomas, 3 rhabdomyosarcomas, 5 neuroblastomas, 2 rhabdoid tumors, 3 lymphomas, and 4 Wilms' tumors. All of the hepatoblastomas expressed Hep Par 1 with a characteristic granular intracytoplasmic pattern that was generally less intense in embryonal-type than in fetal-type hepatoblastomas, perhaps reflecting the degree of hepatocyte differentiation. All of the fetal-type hepatoblastomas expressed pCEA with both an intracytoplasmic and bile canalicular pattern. Embryonal type hepatoblastomas were more likely to be pCEA negative or to show focal or no canalicular pattern of expression, again possibly reflecting the degree of hepatocyte differentiation. All of the hepatoblastomas were mCEA negative. All of the nonhepatoblastomas were Hep Par 1 negative, except for the one hepatocellular carcinoma in this study, which was Hep Par 1 positive. We conclude that Hep Par 1 and pCEA are useful markers for hepatoblastomas, as they have been shown to be in hepatocellular carcinomas.

Adolescent↗

CD44 and its v6 spliced variant in lung tumors: a role in histogenesis?

BACKGROUND: CD44 is a polymorphic family of cell surface glycoproteins with a variety of functions including participation in cell adhesion and migration as well as modulation of cell-matrix interactions. Expression of the standard form of CD44 (CD44s) and its variant isoforms has been shown in both normal and neoplastic tissue and holds promise as a prognostic indicator. METHODS: The authors investigated the expression of CD44s and its v6 isoform (CD44v6) immunohistochemically in 7 fetal lungs (gestational age between 11-36 weeks) and in 80 lung tumors of various histologic types, degrees of differentiation, and clinical stages. RESULTS: In the fetal lung, CD44v6 was expressed as membranous and luminal staining of epithelial cells throughout gestation and basal staining of bronchial epithelium late in gestation. Nonneoplastic adult lung showed CD44v6 expression that was restricted to epithelial cells with membranous staining of basal bronchial cells and squamous metaplasia as well as basolateral membranous staining of type 2 pneumocytes. CD44s showed similar but less intense staining and was in addition present on lymphocytes and macrophages. Tumorlets and neuroepithelial bodies were CD44v6 negative. Nearly all squamous cell carcinomas (97%) were positive for CD44v6 with patterns similar to squamous metaplasia and with more intense staining at the periphery of tumor nests. Most adenocarcinomas (90%) were CD44v6 negative whereas most bronchioloalveolar cell carcinomas (71%) were CD44v6 positive with patterns similar to that in type 2 pneumocytes. Most large cell carcinomas (71%), carcinoid tumors (67%), and all small cell carcinomas were CD44v6 negative. CD44v6 expression did not correlate with clinical stage. CD44v6 expression in lymph node metastases was identical to that of the primary tumor. CONCLUSIONS: The results of the current study show that CD44v6 is localized differently in fetal and adult lung, suggesting a difference in function. In the fetal lung, it may modulate growth factors important in morphogenesis and maturation. In the adult nonneoplastic lung, CD44v6 is associated with stem cells, namely basal cells and type 2 pneumocytes, and may act to anchor these cells to the matrix and be important in migration during repair or neoplasia. In addition, CD44v6 expression is maintained throughout tumorigenesis in squamous cell carcinoma and bronchioloalveolar cell carcinoma, suggesting a histogenetic relationship between the stem cells and the respective tumors. Conversely, most neuroendocrine tumors and the cells of the dispersive neuroendocrine system do not express CD44v6, implying a separate histogenetic lineage in these tumors.

Adult↗

Anti-ulcer activity of cromakalim (BRL 34915), a potassium-channel opener, against experimentally induced gastric and duodenal ulcers in rats and guinea-pigs.

The effect of cromakalim, a potassium-channel opener, was studied on pylorus ligation-induced, aspirin-induced and water-immersion plus restraint stress-induced gastric ulcers in rats and on histamine-induced duodenal ulcer in guinea-pigs. Pretreatment with cromakalim (50-500 micrograms kg-1, p.o.) resulted in a significant reduction in the incidence of gastric and duodenal ulceration in each model. The anti-ulcer activity of cromakalim was comparable with that of cimetidine. Cromakalim at 100, 250 and 500 micrograms kg-1 caused a reduction in the volume of the gastric content in pylorus-ligated rats, and a dose of 250 micrograms kg-1 resulted in a significant reduction in total acidity (28.81 +/- 11.73 mEq L-1, P < 0.02) in the pylorus ligation model. A significant reduction in total acid output was observed at doses of 250 micrograms kg-1 (84.27 +/- 22.33 mEqH+, P < 0.02) and 500 micrograms kg-1 (120.17 +/- 24.49 mEqH+, P < 0.01) in pylorus-ligated rats. A significant reduction in the ulcer index in pylorus-ligated rats was observed at all cromakalim doses: 50 micrograms kg-1 (0.23 +/- 0.09, P < 0.05), 100 micrograms kg-1 (0.15 +/- 0.09, P < 0.02), 250 micrograms kg-1 (0.12 +/- 0.05, P < 0.01) and 500 micrograms kg-1 (0.14 +/- 0.03, P < 0.02). A significant reduction in the ulcer index of aspirin-treated rats was also observed at all cromakalim dose levels: 50 micrograms kg-1 (0.39 +/- 0.03, P < 0.01), 100 micrograms kg-1 (0.28 +/- 0.06, P < 0.01), 250 micrograms kg-1 (0.22 +/- 0.04, P < 0.001) and 500 micrograms kg-1 (0.28 +/- 0.03, P < 0.01). In the water-immersion plus restraint stress-induced gastric ulcer model, cromakalim significantly reduced gastric ulceration at all the dose levels: 50 micrograms kg-1 (28.2 +/- 2.12, P < 0.001), 100 micrograms kg-1 (20.24 +/- 1.71, P < 0.01), 250 micrograms kg-1 (19.95 +/- 1.46, P < 0.001) and 500 micrograms kg-1 (21.61 +/- 3.00, P < 0.001) but there was no consistent reduction of gastric bleeding. In addition to gastric ulcers, duodenal lesions were also reduced by pretreatment with cromakalim at all dose levels: 50 micrograms kg-1 (97.87 +/- 20.03 mm2, P < 0.02), 100 micrograms kg-1 (70.72 +/- 12.82 mm2, P < 0.02), 250 micrograms kg-1 (48.32 +/- 8.42 mm2, P < 0.01) and 500 micrograms kg-1 (55.50 +/- 12.50 mm2, P < 0.01). Cromakalim at a dose of 100 micrograms kg-1 also reduced total acidity (99.36 +/- 9.12 mEqL-1, P < 0.02) and total acid output (172.22 +/- 45.33 mEq of H+, P < 0.05) in this model. These findings demonstrate the anti-ulcer activity of cromakalim in different experimental models and suggest its potential use in ulcer therapy.

Animals↗

Expression of metalloproteinases and tissue inhibitors of metalloproteinases in giant cell tumor of bone: an immunohistochemical study with clinical correlation.

The clinical behavior of giant cell tumors (GCTs) is unpredictable. To gain insight into this tumor's biological behavior, matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs) were studied. These substances play essential roles in wound healing and neoplastic invasion and metastasis. Paraffin-embedded tissue was collected from 18 cases of histologically benign GCT, with 17 treated by curettage and 1 by resection. Eight cases showed no recurrence after a minimum of 2.5 years, and 10 had local recurrence. One showed metastasis. Antibodies to MMP-9, MMP-2, TIMP-1, and TIMP-2 were applied by immunohistochemical methods. In all cases, MMP-9 was strongly expressed in giant cells predominantly in a diffuse pattern and was strong but focal in stromal cells. MMP-2 decorated stromal cells and giant cells heterogeneously. TIMP-1 was variably expressed in giant cells of the nonrecurrent cases and was strongly present in a diffuse or patchy distribution in the stromal cells in 6 of 8 cases. However, in 9 of 10 recurrent cases, TIMP-1 was expressed weakly by both giant and stromal cells. TIMP-2 was variably expressed in the giant cells of the nonrecurrent cases, but 6 of 8 nonrecurrent cases showed strong stromal cell positivity for TIMP-2. Weak staining for TIMP-2 was observed in 7 of 10 recurrent cases in the stromal cells and 9 of 10 recurrent cases in the giant cells. These results indicate that expression of MMPs and TIMPs differs in giant cells and stromal cells in the same tumor. More significantly, in contrast to the nonrecurrent giant cell tumors, there is an imbalance in the MMPs and TIMPs in the recurrent tumors with a net excess of MMPs. This unopposed expression of MMPs in GCTs may play a role in breakdown of extracellular matrix and tissue invasion. Finally, these markers may prove useful in predicting behavior in these tumors.

Adolescent↗

Comparison of p53 and MIB1 expression in benign and borderline areas of ovarian serous tumors.

Ovarian serous tumors of borderline malignancy frequently show morphologically benign and borderline areas within the same tumor. This study was undertaken to determine if these two morphologically disparate areas differ in their proliferative activity and p53 expression. Formalin-fixed, paraffin-embedded archival tissue from 17 ovarian serous borderline tumors with morphologically benign and borderline areas were immunostained with monoclonal antibodies against p53 and MIB1. The percentage of positive cells was determined by counting 100 consecutive cells for each stain in the most intensely stained areas in morphologically benign and borderline portions of these tumors. There was a significantly increased proliferation (MIB1 expression) in borderline areas compared with benign areas (37.05 +/- 15.3 versus 12.88 +/- 6.7, p = 0.0001). More than 30% of cells were positive for MIB1 in 13/17 borderline areas compared with none of the 17 benign areas (p < 0.0001). The expression of p53 was also higher in borderline areas compared with benign areas (7.12 +/- 8.8 versus 2.94 +/- 4.46, p = 0.0078). More than 10% of cells were p53 positive in 5/17 borderline areas compared with 1/17 benign areas (p = 0.08). However, there was no significant correlation between p53 expression and MIB1 expression in either the benign or borderline areas (p = 0.4 and 0.2, respectively). In summary, morphologically borderline areas show significantly higher p53 expression and proliferation compared with morphologically benign areas in ovarian serous borderline tumors. Alterations of p53 may play a pathogenetic role in some ovarian serous borderline tumors. The lack of correlation between p53 expression and MIB1 expression, however, suggests involvement of other factors, in addition to p53, in determining the proliferative rate of ovarian serous borderline tumors.

Antigens, Nuclear↗

Estrogen and progesterone receptor expression in endometrial polyps.

Endometrial polyps are a frequent cause of abnormal uterine bleeding, but their pathogenesis is poorly understood. This study was undertaken to investigate if endometrial polyps result from localized overexpression of estrogen receptors (ERs) or reduced expression of progesterone receptors (PRs). Fourteen cases of endometrial polyps, in which normal cycling endometrium was also present on the same slide, were immunostained for ERs and PRs. Percentages of positive cells in glands and stroma for each receptor were subjectively assessed to the nearest 5%. The intensity of staining was recorded on a scale from 1+ to 4+. The level and intensity of staining in polyps were compared with the staining in normal endometrium. Fewer stromal cells in polyps expressed ERs and PRs compared with cycling endometrium (% ER = 55.9 +/- 25.8 vs. 74.3 +/- 25.8, p = 0.03; % PR = 56.1 +/- 28.2 vs. 87.5 +/- 10.1, p = 0.002). Stroma in polyps also had significantly reduced intensity of staining for PRs, but not for ERs (intensity PR = 2.7 +/- 1.4 vs. 3.5 +/- 0.7, p = 0.015; intensity ER = 2.1 +/- 0.7 vs. 2.4 +/- 0.8, p = 0.45). There were no significant differences in expression of ERs and PRs in the endometrial glands in endometrial polyps compared with normal endometrium (% ER = 75.4 +/- 32.5 vs. 70.7 +/- 39.2. p = 0.25; % PR = 79.6 +/- 32.8 vs. 80.4 +/- 34.4, p = 0.8; intensity ER = 2.7 +/- 0.9 vs. 2.4 +/- 1, p = 0.15; intensity PR = 2.9 +/- 1.4 vs. 3.4 +/- 0.7, p = 0.15). We conclude that endometrial polyps may result from a decrease in ER and PR expression in stromal cells. Because of these receptor-negative stromal cells, endometrial polyps may be relatively insensitive to cyclic hormonal changes.

Adult↗

Transforming growth factor-beta (TGF-beta) in silicosis.

Silicosis is characterized by fibrosing nodular lesions that may eventually develop into progressive massive fibrosis (PMF). Cytokines (interleukin-1beta [IL-1beta], tumor necrosis factor-alpha [TNF-alpha] and growth factors insulin-like growth factor-1 [IGF-1] platelet-derived growth factor [PDGF]) have been implicated in the formation of these lesions. TGF-beta promotes extracellular matrix accumulation by upregulating collagen and fibronectin gene expression, and inhibits matrix degradation by decreasing secretion of proteases and increasing secretion of protease inhibitors. We hypothesized that TGF-beta is associated with matrix deposition and fibrosis in silicosis. To test this hypothesis we studied early and late nodular lesions and PMF (11 cases and two controls) with immunohistochemistry, using rabbit polyclonal antibody to the purified whole molecule of TGF-beta in Bouin's fixed lung tissue. This antibody is reactive with both intra- and extracellular forms of TGF-beta. In the control lungs, small amounts of TGF-beta were present in the bronchial epithelium, macrophages, bronchial and vascular smooth muscle, and bronchial glands. There was minimal to moderate staining in the early silicotic peribronchiolar lesions. In the nodular lesions of silicosis, central hyalinized areas contained the maximum staining for TGF-beta. Fibroblasts in the periphery of the nodular lesions were also positive. In acute silicosis, there was marked staining of hyperplastic alveolar epithelium. Macrophages were markedly positive. In the PMF lesions, large areas of scar tissue contained TGF-beta. These data suggest a major role for TGF-beta in silicosis, particularly in the formation of silicotic nodules and the development of PMF.

Adult↗

Mucin genes are regulated by estrogen and dexamethasone.

This study demonstrates for the first time that mucin gene expression can be significantly up-regulated by steroid hormones. The effects of estrogen, progesterone and dexamethasone on the expression of three mucin genes, MUC1, MUC4 and MUC5c were determined in a human epithelial cell line. This cell line secretes mucin and contains steroid receptors. Steady-state mRNA levels were quantified by slot blot hybridization using radiolabelled oligonucleotide probes. Normally, these genes (originally isolated from airways) are expressed at low constitutive levels. However, steady state levels of MUC4 and MUC5c mRNA were up-regulated at least 3-4 fold by estrogen supplementation, and 1.5-2 fold by dexamethasone. MUC1 mRNA levels were minimally affected. Progesterone supplementation had no effect but was able to interfere with the up-regulation by estrogen. The mechanism of regulation remains to be determined but may be transcriptional. However, steroids have been shown to control gene expression at several different levels.

Cell Line↗

Pharmacologic characterization of wool dust extract in isolated guinea pig trachea.

Wool mill workers develop respiratory symptoms and lung function abnormalities associated with their work in the textile industry. As in other workplaces, which process organic materials, the dust generated in the manufacture of wool has been implicated as a cause of these respiratory problems. Pharmacologic studies of wool dust extract were performed in vitro on guinea pig tracheal (GPT) segments. A wool dust extract (WDE) was prepared from material collected from a mill previously surveyed. When the standardized WDE solution was added to an organ bath in increments of 10, 30, 100, 300, and 1000 microliters it caused a consistent, dose-dependent constriction of GPT. Pretreatment of guinea pig tracheas, prior to WDE challenge, with atropine (10(-6) M), pyrilamine (10(-6) M), indomethacin (10(-6) M), verapamil (10(-6) M), TMBS (10(-6) M), BW755C (10(-6) M) and LY171883 (10(-6) M) was studied in order to evaluate receptor-dependent and -independent characteristics of WDE-induced constriction. WDE-induced bronchoconstriction was partially inhibited by the antihistamine pyrilamine. Atropine and leukotriene inhibitors (LY171883 and BW755C) were not found to have a significant protective effect on WDE-induced constriction. Both TMBS and verapamil (intra- and extracellular calcium blocking agent) suppressed the effect of wool dust extract in the range tested. These findings suggest that in this model, WDE-induced airway constriction is only partly attributable to common mediators of bronchoconstriction (e.g., histamine). The airway effects of WDE may be modulated by calcium channel blocking agents.

Air Pollutants, Occupational↗

Respiratory function in poultry workers and pharmacologic characterization of poultry dust extract.

A group of 343 workers (252 males and 91 females) employed in four poultry farms in Croatia was studied for the prevalence of acute and chronic respiratory symptoms and lung function changes. There were significantly higher prevalences of chronic cough, chronic phlegm, chronic bronchitis, and chest tightness in poultry workers than in control workers. Male poultry workers who were smokers had significantly higher prevalences of chronic cough, chronic phlegm, and chronic bronchitis than poultry workers who were nonsmokers (P<0.01). Poultry workers exposed for more than 10 years had significantly higher symptoms prevalences than those workers with shorter exposures (except among female smokers). There was also a high prevalence in poultry workers of acute symptoms which developed during the work shift. The measured FVC, FEV1, and FEF25 in poultry workers were significantly lower than predicted normal values. Workers exposed for more than 10 years had lower ventilatory capacity tests (expressed as percentage of predicted) than those workers with shorter exposures. Changes in FEV1, FEF50, and FEF25 were less pronounced than FVC. Additionally we showed that a water-soluble poultry dust extract obtained from this workplace caused a dose-related contraction of nonsensitized guinea pig tracheal smooth muscle when studied in vitro. Pharmacologic studies of this response indicate that it may result from the release of multiple endogenous mediators. Our data suggest that work in poultry farms may, for some workers, cause the development of acute and chronic respiratory symptoms and lung function changes.

Adult↗

Cervical squamous dysplasias and carcinomas with immunodetectable p53 frequently contain HPV.

Studies using cervical carcinoma cell lines usually show mutated p53 in cases without detectable HPV, and wild-type p53 in cases with detectable HPV. These findings suggest that loss of p53 function, either by mutation or by binding to HPV E6, is required for cervical carcinogenesis. Because mutated p53 is usually detectable immunohistochemically, one would predict an inverse relationship between the presence of HPV and detectable p53. In this study we examined 88 formalin-fixed paraffin-embedded clinical specimens of cervix for the presence of HPV and p53 expression. All cases were studied for the presence of p53 using immunohistochemical methods. The antibody used was mouse monoclonal PAb1801 (Biogenex). The presence of HPV was detected by PCR. Twenty-six specimens showed foci of p53 expression (0/7 normal, 1/8 (13%) condylomas, 1/6 (17%) CIN I, 3/7 (43%) CIN II, 6/20 (30%) CIN III, 13/22 (59%) SCC, 2/5 (40%) adenosquamous carcinomas, and 0/13 adenocarcinomas). p53 expression was more frequent in SCC than with CIN (P = 0.026). HPV was present in 15 of 24 cases with detectable p53 and 22 of 48 cases without detectable p53. No correlation was seen between HPV status and detection of p53. With the exception of one case, p53 expression was seen in less than 10% of cells. p53 expression was not detected in any of the 13 adenocarcinomas examined (P = 0.0016 vs SCC). Our results show that alterations of p53 may play a role in the pathogenesis of cervical squamous carcinoma. However, p53 expression was neither sufficient nor required for cervical carcinogenesis, irrespective of HPV status.

Adenocarcinoma↗

Immunohistochemical profile of ovarian inclusion cysts in patients with and without ovarian carcinoma.

The expression of cytokeratin, epithelial membrane antigen, Leu-M1, B72.3, carcinoembryonic antigen, human placental lactogen, proliferating cell nuclear antigen, p53, and ovarian carcinoma-associated antigen OC-125 was evaluated in inclusion cysts in contralateral ovaries of patients with unilateral ovarian carcinoma. The findings were compared with the findings in inclusion cysts in ovaries of patients without ovarian carcinoma. Although there was more frequent expression of tumour markers B72.3 and CEA in patients with ovarian carcinoma, these differences did not reach statistical significance.

Biomarkers, Tumor↗

Detection of a novel macrophage-derived mucus secretagogue (MMS-68) in bronchoalveolar lavage fluid of patients with asthma.

BACKGROUND: We have previously described a novel high-molecular-weight macrophage-derived mucus secretagogue (MMS-68) that causes mucuslike glycoconjugate release from cultured airways, nasal explants, and the Ishikawa adenocarcinoma cell line. We have generated monoclonal antibodies against MMS-68 and have developed an antigen-capture ELISA to measure MMS-68 levels in biologic fluids. Using this ELISA, we have demonstrated elevated levels of MMS-68 in the bronchoalveolar lavage fluid (BALF) of smokers and persons chronic bronchitis, in a patient with asthma and bronchorrhea, and in nasal lavage from patients with allergic rhinitis challenged with histamine and methacholine. We have also demonstrated that both spontaneous and lipopolysaccharide induced MMS-68 production is increased in the culture supernatants of monocytes from patients with steroid-dependent asthmas compared with those from normal control subjects. METHODS: To delineate further a role for MMS-68 in the regulation of mucus secretion in asthma, we measured MMS-68 levels in the BALF of 37 patients with non-steroid-dependent asthma and of 16 control subjects. RESULTS: There were 21 men and 16 women in the asthma group (age range, 17 to 62 years; mean, 33.8 years) and 11 men and five women in the control group (age range, 18 to 42 years; mean, 27.8 years). There were no statistical differences in either total cell count (145.5 x 103 +/- 75.7 cells/mm3 x 10(3) cells/mm3 vs 134 x 103 +/- 65.9 x 10(3) cells/mm3, p < 0.234) or numbers of alveolar macrophages (103.7 x 10(3) +/- 71.7 x 10(3)/mm3 vs 98.7 x 10(3) +/- 65 x 10(3) cells/mm3, p < 0.244) when the asthmatic group was compared with the control group. The MMS-68 level in the asthmatic group was 2.1 +/- 0.25 micrograms MMS-68 per milligram protein compared with 2.09 +/- 0.26 micrograms MMS-68 per milligram protein (p < 0.256) in the control group. CONCLUSIONS: There was no correlation between MMS-68 levels and total protein content, numbers of alveolar macrophages, or the production of other macrophage-derived cytokines including interleukin-1, interleukin-6, or tumor necrosis factor in the asthmatic BALF. Mild asthma, which is clinically not associated with mucus hypersecretion, was not associated with elevated levels of MMS-68. We believe that direct correlation exists between mucus hypersecretion and MMS-68 levels.

Adolescent↗

Congenital cystic adenomatoid malformation of the lung: insights into the pathogenesis utilizing quantitative analysis of vascular marker CD34 (QBEND-10) and cell proliferation marker MIB-1.

Congenital cystic adenomatoid malformation (CCAM) encompasses a spectrum of variably cystic developmental anomalies of the lung histologically characterized by immature lung tissue. The pathogenesis is uncertain, but many investigators favor a maturation arrest in bronchopulmonary development. To investigate this hypothesis, the vascular development and proliferation capacity of lung tissue with CCAM type I from nine infants ranging in age from 20 weeks gestation to 42 days old were studied immunohistochemically utilizing CD34 for the former and MIB-1 for the latter. Both markers were quantitated on an image analysis system. CCAM was hypovascular with a mean vascular index of 20.05% +/- 6.58 compared to 40.06% +/- 4.19 for the age-matched controls (P < 0.000001). The proliferation index of both epithelial and mesenchymal components was higher in CCAM (10.46 +/- 3.48) than in control tissue (7.14 +/- 1.88; P < 0.012). In contrast to the control lung tissue which showed a remarkable synchrony between the vascular development and proliferation throughout the parenchyma, focal asynchrony between the proliferation of the epithelial and stromal components was noted in CCAM. The vascularity in CCAM corresponds to that seen in early gestation. The cellular proliferation in CCAM is higher than in full-term infants and corresponds to late second trimester or early third trimester fetuses. These findings support the proposed pathogenesis of a maturation defect in lung embryogenesis.

Antigens, CD34↗

Mycotin: a lectin involved in the adherence of Mycobacteria to macrophages.

Pathogenic Mycobacteria colonize host macrophages. Attachment of these organisms to macrophages is the preliminary step prior to invasion of the macrophages by the bacteria. Western blot confirmed that walls of Mycobacterium avium and Mycobacterium tuberculosis contain molecules which are immunologically related to mycotin, a lectin found in Mycobacterium smegmatis. We have demonstrated that the adherence of Mycobacteria to macrophages is significantly inhibited by anti-mycotin antibody or the mycotin-specific sugar, mannan. These observations suggest that prevention of the interaction of mycotin-related molecules on the surfaces of Mycobacteria with mannose-specific receptors on macrophages, offers an important approach for blocking attachment of pathogenic Mycobacteria to macrophages, thereby preventing infection.

Animals↗

Increased expression of transforming growth factor beta isoforms and basic fibroblast growth factor in complex hyperplasia and adenocarcinoma of the endometrium: evidence for paracrine and autocrine action.

Endometrial carcinoma is associated with antecedent simple and complex hyperplasia, and the endometrium is a target tissue for the action of cytokines and growth factors. Transforming growth factor (TGF)-beta s are potent cellular growth and differentiation regulatory factors. Therefore, we investigated the potential role for TGF-beta s in the normal proliferative endometrium and its possible involvement in the transition to complex hyperplasia and progression to endometrial carcinoma. The angiogenic and mitogenic growth factor, basic fibroblast growth factor, was used for comparison. Differential TGF-beta isoform-specific immunoreactivity was observed in the normal endometrium, which is composed of glandular and stromal cells. There was an increase in TGF-beta 3 but not TGF-beta 1 or TGF-beta 2 in the glandular epithelium from the proliferative to the secretory phase of the menstrual cycle. Immunostaining for TGF-beta 2 was more intense in the stroma than the glands. In contrast, TGF-beta 1 and TGF-beta 3 were near equal intensity in these two endometrial compartments, TGF-beta 3 being the most intense. The glandular epithelium demonstrated a statistically significant stepwise increase in the expression of all three TGF-beta s progressing from the normal proliferative endometrium to simple hyperplasia and on to complex hyperplasia. However, the stromal cells maintained approximately the same level of immunoreactivity for TGF-beta in all these samples. In comparing proliferative endometrium with complex hyperplasia, there was a 5.1-, 3.4-, and 2.6-fold increase in immunostaining in the glands for TGF-beta 1, TGF-beta 2, and TGF-beta 3, respectively (P < or = 0.001). There was no further increase in immunoreactivity with progression from preneoplastic complex hyperplasia to carcinoma. Immunoreactive basic fibroblast growth factor was slight in normal endometrium and simple hyperplasia. There was a 4.6- and 4.2-fold increase in immunostaining observed in complex hyperplasia compared with proliferative endometrium in the glandular (P < or = 0.0054) and stromal (P < or = 0.0053) cells, respectively, with no further increase in carcinoma. By in situ hybridization, an increase in mRNA for all TGF-beta isoforms paralleled TGF-beta immunoreactivity. However, in contrast to the increased immunostaining in the glands in complex hyperplasia, there was remarkably more mRNA in the stromal cell compartment. The discordant expression of mRNA and protein was only observed in the pathological endometrium since both were more highly expressed in the stromal cells in normal proliferative endometrium.(ABSTRACT TRUNCATED AT 400 WORDS)

Adenocarcinoma↗

Differential expression of the myocyte enhancer factor 2 family of transcription factors in development: the cardiac factor BBF-1 is an early marker for cardiogenesis.

In the present study, we have used single chicken blastoderms of defined early developmental stages, beginning with the prestreak stage, stage 1 (V. Hamburger and H. L. Hamilton, J. Morphol. 88:49-92, 1951), to analyze the onset of cardiac myogenesis by monitoring the appearance of selected cardiac muscle tissue-specific gene transcripts and the functional expression of the myocyte enhancer factor 2 (MEF-2) proteins. Using gene-specific oligonucleotide primers in reverse transcriptase PCR assay, we have demonstrated that the cardiac myosin light-chain 2 (MLC2) and alpha-actin gene transcripts appear as early as stage 5, i.e., immediately after the cardiogenic fate assignment at stage 4. Consistent with this observation is the developmental expression pattern of DNA-binding activity of BBF-1, a cardiac muscle-specific member of the MEF-2 protein family, which also begins at stage 5 prior to MEF-2. Differential expression of DNA-binding complexes is also observed with another AT-rich DNA sequence (CArG box) as probe, but the binding pattern with the ubiquitous TATA-binding proteins remains unchanged during the same developmental period. Thus, the cardiogenic commitment and differentiation of the precardiac mesoderm, as exemplified by the appearance of cardiac MEF-2, MLC2, and alpha-actin gene products, occur earlier than previously thought and appear to be closely linked. The onset of skeletal myogenic program follows that of the cardiogenic program with the appearance of skeletal MLC2 at stage 8. We also observed that mRNA for the MEF-2 family of proteins appears as early as stage 2 and that for CMD-1, the chicken counterpart of MyoD, appears at stage 5. The temporal separation of activation of cardiac and skeletal MLC2 genes, which appears immediately after the respective fate assignments, and those of cardiac MEF-2 and CMD-1, which occur before, are consistent with the established appearance of the myogenic programs and with the acquisition pattern of the two tissue-specific morphological characteristics in the early embryo. The preferential appearance of BBF-1 activity in precardiac moesderm, relative to that of MEF-2, indicates that these two protein factors are distinct members of the MEF-2 family and provides a compelling argument in support of the potential role of BBF-1 as a regulator of the cardiogenic cell lineage determination, while cardiac MEF-2 might be involved in maintenance of the cardiac differentiative state.

Age Factors↗