Evaluation of danazol influence upon the uterus using scanning electron microscopic morphometric and biochemical analyses

A study using a Sprague-Dawley rat model was designed to correlate morphologic and intracellular steroid receptor alteration with danazol therapy. One uterine horn was removed for cytoplasmic estrogen receptor analysis following four to eight days of danazol therapy. This was followed by intra-aortic injection of buffered phosphate solution and 3 per cent glutaraldehyde. The remaining uterine horn was removed for scanning electron microscopic and morphometric analysis of light microscopic changes. After four days of treatment, there was an increase in the nuclear to cytoplasmic ratio compared with that of the control tissue. Vaginal smears on the eighth day of danazol exposure indicated that the rats had entered a noncycling estrus state, and there was a significant increase in the estrogen-specific binding capacity of the endometrial cells. Scanning electron microscopy showed a distinct decrease in endometrial folds, microvilli and glandular openings, which suggests a decline in secretory activity in the danazol-treated group. Thus, danazol induced measurable changes in the estrogen binding capacity of endometrial cells, and these changes correlated with certain morphologic alterations in the endometrial lining.     

Investigation of the anxiolytic effects of naringenin, a component of Mentha aquatica, in the male Sprague-Dawley rat

This was a prospective, randomized, between-subjects experimental study to investigate the anxiolytic effects of naringenin, a component of mentha aquatica, and its potential interaction with the benzodiazepine binding site on the γ-aminobutyric acid (GABAA) receptor in the rat. Fifty-five rats were assigned to one of 5 groups with 11 rats per group: control, naringenin, midazolam, midazolam with naringenin, and flumazenil with naringenin. The elevated plus maze measured the behavioral components of anxiety and motor movements. Our data suggest that naringenin does not produce anxiolysis by modulation of the GABAA receptor; however, the findings indicate that naringenin decreases motor movements (P < .05).     

Fiberoptic bronchoscopy and pleural effusion of unknown origin

We reviewed our experience with fiberoptic bronchoscopy (FOB) in patients with pleural effusion of unknown origin. Seventy patients underwent FOB for the investigation of pleural effusion between 1978 and 1983. Those with a second reason for FOB, a mass on chest roentgenogram, or lobar atelectasis were excluded. Forty five patients remained: 28 patients with unexplained pleural effusion after pleural fluid analysis and pleural biopsy (UPE), and 17 patients with malignant pleural fluid cytology and/or pleural biopsy but no known primary tumor (MPE). In the UPE group, only one FOB demonstrated malignancy, despite a final diagnosis of tumor in seven. No other specific diagnoses were made by FOB in this group. In the MPE group, FOB demonstrated bronchogenic carcinoma in two; ultimately, five patients were found to have a bronchogenic neoplasm. Although pleural effusion of unknown origin is frequently caused by bronchogenic carcinoma, FOB in the absence of other indications for this procedure is rarely diagnostic and should not be routinely employed.     

Characterization of revertants of the CHO EM9 mutant arising during DNA transfection

We have studied reversion in DNA repair deficient EM9 cells, by selection for ethylmethanesulfonate (EMS) resistance. EM9 is a mutant CHO cell line that is hypersensitive to killing by EMS and X-rays and deficient in DNA single-strand break (SSB) repair. EM9 cells were transfected with DNA from a cosmid library, and transfectants resistant to EMS were isolated. Four revertant lines were obtained, which varied in their sensitivity to killing by EMS, ionizing radiation and other genotoxic agents. When the cell lines were analyzed for resistance to killing by chlorodeoxyuridine (CldUrd) or N-methyl-N'-nitro-N-nitrosoguanidine (MNNG), a different relative ranking among the cell lines was observed. The recently cloned human XRCC1 gene is capable of correcting the deficiencies of the EM9 cell line. Using the human XRCC1 cDNA (pXR1-30) as a probe, we determined that the resistant-transfectant cell lines contained only the endogenous hamster XRCC1 gene, implying that a hamster XRCC1 gene was altered during the transfection/selection procedure and was responsible for the EMS resistance. In these cells the levels of XRCC1 mRNA corresponded roughly to the degrees of resistance of the reverted cell lines to killing by EMS or X-rays. The degree of increased resistance to killing by EMS or X-rays also roughly correlated with increased SSB repair. These results suggest that increased cellular levels of the endogenous XRCC1 gene mRNA may largely, though not completely, explain the phenotypes of revertant, EMS-resistant EM9 cell lines.     

AK37: the first pyridoacridine described capable of stabilizing the topoisomerase I cleavable complex

Pyridoacridines are marine natural products that contain planar structures. Almost all are cytotoxic and capable of DNA intercalation. Several pyridoacridines have demonstrated anti-cancer activity, being able to generate reactive oxygen species or to inhibit topoisomerase (Topo) II. Synthetic pyridoacridines were characterized and compared to other pyridoacridines as well as the Topo-inhibiting drugs (etoposide, 9-aminocamptothecin and wakayin) in a series of in vitro enzyme systems. We found AK37 was able to stabilize a DNA-Topo I cleavable complex, but not a DNA-Topo II cleavable complex. To our knowledge, this is the first report of a DNA-Topo I cleavable complex stabilizing pyridoacridine. Structure comparison studies demonstrated that this activity was lost when an extra 'F' ring was added, but activity was not affected when the 'D' ring was removed. AK37 inhibited the catalytic activity of both human Topo I and II.     

Interleukin-1 family expression in human breast cancer: interleukin-1 receptor antagonist

We hypothesize that interleukin-1 alpha, beta, and receptor antagonist (IL-1 alpha, IL-1 beta, and IL-1 ra, respectively) are present and tumor cell associated in human breast cancer (HBC). We believe the levels of these cytokines in breast tumor homogenates relate to other known prognosticators of patient survival (i.e., estrogen receptor [ER] status). Our results demonstrated that, immunohistochemically, tumor cells express IL-1 alpha, IL-1 beta, and IL-1 ra in most specimens tested. In breast tissue homogenates, IL-1 alpha levels correlated inversely with ER levels (p < 0.06), whereas IL-1 ra levels correlated directly with both ER levels (p < 0.009) and IL-1 beta levels (p < 0.06). When analyzing cytokine levels for the ER (-) versus ER (+) patient groups, we found that in many instances these groups showed a different cytokine profile. These studies suggest that the IL-1 family of cytokines may be important in regulating protumorigenic activities within the HBC tumor microenvironment.     

Immunochemical detection of human blood in feces.

Current methods for testing stool samples for hemoglobin utilize peroxidase oxidation of chemical indicators such as guaiac or benzidine. These tests have frequent false-positive and false-negative results, complicating random screening for occult gastrointestinal bleeding. The authors have developed an immunochemical test for human blood in feces using goat antibodies to hemoglobin. When employed in radial immunoassay the test is uncomplicated by cross-reaction with common human foods or other nonhemorrhagic fecal fecal constitutents. The lower limit of sensitivity for hemoglobin in stool samples is 10 mg/dl, compared with a commonly reported threshold of 100 mg/dl for peroxidase tests. The test accurately detects hemoglobin in mixtures of human blood and feces. Immunochemical identification of human blood in stool offers improved detection of lower gastrointestinal bleeding.     

Transfectant CHO cells expressing O6-alkylguanine-DNA-alkyltransferase display increased resistance to DNA damage other than O6-guanine alkylation

BCNU [1,3-bis(2-chloroethyl)-1-nitrosourea, Carmustine] is anitrosourea that crosslinks DNA and is useful in cancer chemotherapy.Tumor cells resistant to BCNU produce high levels of O⁶-alkylguanine-DNA-alkltransferase(AT), a protein that removes the O⁶-guanine adduct formed byBCNU prior to crosslinking. By the transfection of a human cosmidlibrary into the Chinese hamster ovary cell line AA8, severaltransgenic cell lines which express the AT gene have been constructed.These ‘BR’ cells were isolated on the basis of theirresistance to G-418 and BCNU. Like human mer⁺ strains, BR cells(relative to the parental AA8 cells) are {small tilde}500 timesmore resistant to the cytotoxic effects of 80 µM BCNU.Treatment with exogenous O⁶-methylguanine (O⁶MG), which depletescellular AT, abolishes their BCNU resistance. Also consistentwith the mer⁺ phenotype, BR cells are resistant to the mutagenicand killing activity of N-methyl-N'-nitro-N-nitrosoguanidine(MNNG). Treatment with exogenous O⁶MG, while reversing the resistanceto MNNG mutation, does not reverse the resistance to MNNG killing.Unexpectedly, BR cells also exhibit resistance to killing bydimethylsulfate (DMS). The BR cells are not, however, detectablyresistant to UV light. These results suggest that AT activityin mammalian cells is dosely linked to the activity of otherDNA repair pathways.