Breathing during sleep in patients with nocturnal desaturation

BACKGROUND: The global DNA methylation of 136 breast lesions (117 primary invasive carcinomas, 5 benign phyllodes tumors, 11 fibroadenomas, and 3 sclerosing adenosis) and their respective adjacent parenchyma was analyzed using an in vitro enzyme assay. METHODS: In the group of patients with breast carcinoma, DNA hypomethylation was correlated with clinical and pathologic parameters known to affect disease prognosis. Histopathologic type, disease stage, and tumor grade were evaluated according to the World Health Organization classification, the TNM system, and the criteria of Elston and Ellis' criteria, respectively. DNA flow cytometry was performed in fresh/frozen samples stained with propidium iodide. Hormone receptor (estrogen and progesterone receptor) status was determined by immunocytochemistry. RESULTS: The comparative study of DNA methylation showed that the DNA of breast carcinomas was statistically significantly less methylated than the DNA of the respective adjacent parenchyma (P=0.0001), the DNA of breast benign lesions (P=0.0002), and the DNA of normal parenchyma (P < 0.0001). A statistically significant correlation was found between the global DNA hypomethylation and the disease stage (P=0.0009), tumor size (P=0.0026), and histologic grade (P=0.0097) of malignant neoplasms. A trend for DNA from breast carcinomas with positive axillary lymph nodes (N1) to be more hypomethylated than those without nodal involvement (NO) (P=0.055) was verified. In contrast, no significant association was found between DNA methylation and histologic type of tumors, hormone receptors, DNA ploidy, and S-phase fraction. CONCLUSIONS: The current shows that DNA hypomethylation is increased in breast carcinomas, playing a potentially important role in tumor development. These findings also suggest that DNA methylation status may be a biologic marker with prognostic significance in this group of neoplasms.     

Complications of internal fixation of maxillofacial fractures with microplates

PURPOSE: The aim of this retrospective study was to evaluate the complications of open reduction and internal fixation of maxillofacial fractures with microplates. PATIENTS AND METHODS: In 44 patients with maxillofacial trauma, fractures of the maxillofacial skeleton were treated by open reduction and internal fixation using a 1.0-mm and 1.5-mm microsystem. Simultaneously occurring fractures of the mandible or frontozygomatic suture were treated with a 2.0-mm miniplate system. Perioperative and postoperative complications were traced using patient charts, operation reports, and radiographs. The average follow-up was 46.8 months (range, 31 to 54 months). RESULTS: A total of 124 1.0-mm microplates and 546 1.0-mm microscrews, and 17 1.5-mm microplates and 75 1.5-mm microscrews, was used. The perioperative complication rate was 1.2% for the 1.0-mm screws (use of four emergency screws, breakage of one screw in the dense frontozygomatic suture area, and an insertion of a screw in a premolar root). The postoperative complication rate was 0.8% for the 1.0-mm screws (screw dislocation without clinical implication). No complications were observed with the 1.5-mm system. Plate-related infection did not occur. All fractures healed well. Three patients asked for plate removal because of a vague, persisting pain in the treated area. After removal, only one patient was free of pain. A loose 1.5-mm screw was found in this patient. CONCLUSION: The overall complication rate for microsystems was 2.0%. Both microsystems proved to be a reliable modality to fix fractures of the maxillofacial skeleton. Complications can be considered incidental and of neglectable clinical significance.     

Agreement and repeatability of infrared pupillometry and the comparison method

OBJECTIVE: To evaluate the accuracy and repeatability of the widely used comparison method of measuring pupil size. DESIGN: Cross-sectional study. PARTICIPANTS: Fourteen eyes of seven healthy myopic subjects were examined. INTERVENTION: Two examiners made two repeated measures of pupil diameters of 14 eyes using Rosenbaum card comparison pupillometry and infrared pupillometry. Subjects fixated on a distant visual acuity chart, and pupils were measured under three luminance conditions. The agreement and inter-rater repeatability of both methods were determined. MAIN OUTCOME MEASURES: Outcomes were pupil diameters, limits of agreement, and coefficient of repeatability of two examiners. RESULTS: The mean difference between the two techniques ranged from 0.3 to 0.5 mm. The limits of agreement within two standard deviations ranged from 2.4 to 2.8 mm. Coefficient of repeatability ranged from 0.6 to 1.4 mm for infrared pupillometry and 1.0 to 1.2 mm for Rosenbaum pupillometry. Inter-rater repeatability of Rosenbaum pupillometry was consistently pupil diameter biased. Pupil diameters measured with the Rosenbaum method were consistently larger than diameters measured with the infrared technique for both examiners under all luminance conditions. CONCLUSIONS: Results indicate that although the mean difference in techniques was small, the range of the agreement between the Rosenbaum and the infrared techniques was large. The Rosenbaum method consistently overestimated pupil diameters and was subject to inter-rater repeatability bias. Rosenbaum pupillometry may not be appropriate when accurate pupil measurements are required. The results have implications for many clinical trials in ophthalmology, including those evaluating refractive surgery that use Rosenbaum comparison pupillometry.     

Expansion and deletion of triplet repeat sequences in Escherichia coli occur on the leading strand of DNA replication

Expansions and deletions of triplet repeat sequences that cause human hereditary neurological diseases were previously suggested to be mediated by the formation of DNA hairpins on the lagging strand during replication. The replication properties of CTG.CAG, CGG.CCG, and TTC.GAA repeats were studied in Escherichia coli using an in vivo phagemid system as a model for continuous leading strand synthesis. The repeats were substantially deleted when the CTG, CGG, and GAA repeats were the templates for rolling circle replication from the f1 phage origin. The deletions may be mediated by hairpins formed by these repeat tracts. The distributions of the deletion products of the CTG.CAG and CGG.CCG tracts indicated that hairpins of discrete sizes mediate deletions during complementary strand synthesis. Deletions during rolling circle synthesis are caused by larger hairpins of specific sizes. Thus, most deletion products were of defined lengths, suggesting a preference for specific hairpin intermediates. Small expansions of the CTG.CAG and CGG.CCG repeats were also observed, presumably due to the formation of CTG and CGG hairpins on the nascent complementary strand. Since rolling circle replication has been established in vitro as a model for leading strand synthesis, we conclude that triplet repeat instability can also occur on the leading strand of DNA replication.     

Latissimus dorsi pedicled graft. An unusual cause of shoulder pain

An unusual complication after the use of a pedicled latissimus dorsi flap is reported. The flap was used to reconstruct a facial defect after excision of a high grade mucoepidermoid carcinoma of a parotid gland. The tendinous insertion of the latissimus dorsi on the humerus was left intact and the flap pivoted around this point. Subsequent use of his arm caused the patient disabling shoulder pain from traction on the tendon. Symptoms resolved after the tendon was divided.     

Combining Designer Cells and Click Chemistry for a One‐Pot Four‐Step Preparation of Enantiopure β‐Hydroxytriazoles

The multistep catalytic process using designer cells, either added as freshly prepared suspensions or as stable lyophilized powder, and click reaction can be performed in one pot. The sequence of four reactions allows the production of both enantiomers of β‐hydroxytriazoles with high enantiomeric excess.     

Readiness of zebrafish brain neurons to regenerate a spinal axon correlates with differential expression of specific cell recognition molecules

We analyzed changes in the expression of mRNAs for the axonal growth-promoting cell recognition molecules L1.1, L1.2, and neural cell adhesion molecule (NCAM) after a rostral (proximal) or caudal (distal) spinal cord transection in adult zebrafish. One class of cerebrospinal projection nuclei (represented by the nucleus of the medial longitudinal fascicle, the intermediate reticular formation, and the magnocellular octaval nucleus) showed a robust regenerative response after both types of lesions as determined by retrograde tracing and/or in situ hybridization for GAP-43. A second class (represented by the nucleus ruber, the nucleus of the lateral lemniscus, and the tangential nucleus) showed a regenerative response only after proximal lesion. After distal lesion, upregulation of L1.1 and L1.2 mRNAs, but not NCAM mRNA expression, was observed in the first class of nuclei. The second class of nuclei did not show any changes in their mRNA expression after distal lesion. After proximal lesion, both classes of brain nuclei upregulated L1.1 mRNA expression (L1.2 and NCAM were not tested after proximal lesion). In the glial environment distal to the spinal lesion, labeling for L1.2 mRNA but not L1.1 or NCAM mRNAs was increased. These results, combined with findings in the lesioned retinotectal system of zebrafish (Bernharnhardt et al., 1996), indicate that the neuron-intrinsic regulation of cell recognition molecules after axotomy depends on the cell type as well as on the proximity of the lesion to the neuronal soma. Glial reactions differ for different regions of the CNS.