ABSTRACT
We describe the cloning and characterization of a novel rat gene, bwd (brain-enriched WD), which encodes a protein with four copies of the WD amino acid motif, suggesting involvement in protein-protein interaction and a regulatory function in the cell. Northern analysis reveals two size classes of mRNA (1.8 and 2.2 kb), expressed in many adult tissues and developmental stages. Expression is highest in brain, where the longer of the two RNAs predominates. cDNA sequences show that both RNAs encode the identical protein, differing only in their 3' untranslated regions, where the longer transcript contains two RNA instability signals (AUUUA). In situ hybridization to bwd RNA in adult brain shows a highly restricted pattern, localizing expression mainly to the Purkinje and granule neurons of the cerebellum, the pyramidal cells of the hippocampus, and the dentate gyrus. In cryosections of rat cerebellum and kidney, BWD is shown by immunohistochemistry to be localized in the nucleus and cytoplasm of cerebellar Purkinje and granule neurons, and in predominantly the cytoplasm of cells surrounding kidney ducts. Taken together, these results suggest a specialized function for BWD in the brain. Sequence similarity comparisons with bwd reveal structural homologs of unknown function in human, mouse, Drosophila, Arabidopsis and C. elegans, and provide evidence that this set of sequences forms a new subfamily of WD-repeat genes. By sequence comparisons with expressed sequence tags (ESTs), the human homolog of bwd is predicted to reside in the chromosome 1q12-23 region, where several genetic diseases are known to map.
Subject(s)
Brain/metabolism , Nerve Tissue Proteins/genetics , Repetitive Sequences, Amino Acid/genetics , Amino Acid Sequence , Animals , Base Sequence , Blotting, Northern , Brain/embryology , Chromosome Mapping , Cloning, Molecular , DNA, Complementary/chemistry , DNA, Complementary/genetics , Female , Gene Expression , Gene Expression Regulation, Developmental , Immunohistochemistry , In Situ Hybridization , Molecular Sequence Data , Nerve Tissue Proteins/metabolism , RNA, Messenger/genetics , RNA, Messenger/metabolism , Rats , Sequence Alignment , Sequence Analysis, DNA , Sequence Homology, Amino Acid , Tissue DistributionABSTRACT
STUDY OBJECTIVE: Our objective was to determine the respiratory and acid-base metabolism response to endoscopic laser surgery for obstructive tumors, as related to the duration and different types of endoscopy, anesthesia, and laser treatment. DESIGN: The design was a case-control, cohort analytic, nonrandomized controlled survey of case series before and after endoscopic procedures. SETTING: A referral-based surgery and oncology practice at one hospital's laser center. PATIENTS: We studied a sequential sample of 82 patients in the age range from 35 to 92 years, with malignant and benign, primary and metastatic, partially and completely obstructing esophageal (15 patients) and endobronchial (67 patients) tumors. INTERVENTIONS: A total of 229 diagnostic, laser treatment, and follow-up endoscopic procedures was performed under general or local anesthesia (46 esophagoscopies and 183 bronchoscopies). The latter group consisted of 29 cases of general and 154 cases of local topical anesthesia. The last group involved 37 diagnostic and toilet bronchoscopies, 86 cases of YAG-laser tumor ablation, and 31 cases of PDT. MEASUREMENTS AND MAIN RESULTS: Direct-reading electrode measurements of arterial blood, sampled before and immediately after the endoscopic procedure, revealed statistically significant (p less than 0.001) increases in PaCO2 (200 of 229 cases) and decreases in pH (195 of 229 cases) and PaO2 (215 of 229 cases). These findings were similar after bronchoscopy and esophagoscopy, general and local anesthesia (only the decrease in pH was less pronounced in the latter case), and explorative endoscopies and different laser treatments and did not correlate with the total duration of the procedure within the wide time range of 7 to 210 minutes. The initial preoperative level of PaCO2 was considerably higher and the level of PaO2 was significantly lower in patients with endobronchial tumors, as compared to patients with esophageal cancer. A strong, inverse linear relationship was found between the perioperative changes in PaO2 and its initial level and between PaCO2 and pH changes. CONCLUSIONS: The PDT for esophageal and endobronchial malignancies is no more harmful for acid-base metabolism and respiratory functions than YAG-laser tumor ablation or any other common, nonlaser endoscopic procedure.
