Interchromosomal Colocalization with Parental Genes Is Linked to the Function and Evolution of Mammalian Retrocopies.

Retrocopies are gene duplicates arising from reverse transcription of mature mRNA transcripts and their insertion back into the genome. While long being regarded as processed pseudogenes, more and more functional retrocopies have been discovered. How the stripped-down retrocopies recover expression capability and become functional paralogs continually intrigues evolutionary biologists. Here, we investigated the function and evolution of retrocopies in the context of 3D genome organization. By mapping retrocopy-parent pairs onto sequencing-based and imaging-based chromatin contact maps in human and mouse cell lines and onto Hi-C interaction maps in 5 other mammals, we found that retrocopies and their parental genes show a higher-than-expected interchromosomal colocalization frequency. The spatial interactions between retrocopies and parental genes occur frequently at loci in active subcompartments and near nuclear speckles. Accordingly, colocalized retrocopies are more actively transcribed and translated and are more evolutionarily conserved than noncolocalized ones. The active transcription of colocalized retrocopies may result from their permissive epigenetic environment and shared regulatory elements with parental genes. Population genetic analysis of retroposed gene copy number variants in human populations revealed that retrocopy insertions are not entirely random in regard to interchromosomal interactions and that colocalized retroposed gene copy number variants are more likely to reach high frequencies, suggesting that both insertion bias and natural selection contribute to the colocalization of retrocopy-parent pairs. Further dissection implies that reduced selection efficacy, rather than positive selection, contributes to the elevated allele frequency of colocalized retroposed gene copy number variants. Overall, our results hint a role of interchromosomal colocalization in the "resurrection" of initially neutral retrocopies.

Sucking lollipop after awakening from sevoflurane anesthesia reduces the degree of emergence agitation in children undergoing ambulatory surgery: A prospective randomized controlled trial.

BACKGROUND: Emergence agitation (EA) is a common complication in pediatric anesthesia, especially in preschool children maintained by sevoflurane, with incidence ranging up to 80%. The purpose of the study was to determine whether sucking lollipop after awakening from sevoflurane anesthesia reduced the degree of EA in children undergoing ambulatory surgery. METHODS: In this prospective study, 40 children aged 2 to 6 years scheduled for ambulatory surgery with sevoflurane were enrolled. They were randomly allocated to 1 of 2 groups after evaluating baseline EA levels using the pediatric anesthesia emergence delirium (PAED) scale immediately after awakening from general anesthesia: group L (sucking lollipop) or group C (control group, without sucking lollipop). The primary outcome was the overall PAED score after intervention. Pain score, parental satisfaction, the incidence of propofol rescue and negative postoperative behavioral changes (NPOBCs) were assessed. RESULTS: The overall PAED score after intervention was significantly lower in Group L compared with Group C, with an estimated difference of -1.857 (95% CI, -2.884 to -0.831; P < .001) using generalized estimating equations. However, no significant intergroup differences were observed in the pain score, parental satisfaction, the incidence of propofol rescue and NPOBCs. CONCLUSIONS: Sucking lollipop after awakening from sevoflurane anesthesia reduced the degree EA in children undergoing ambulatory surgery.

[The surgical management of parapharyngeal space neoplasms with skull base involved].

OBJECTIVE: To describe the most appropriate treatment to parapharyngeal space tumors with skull base involved. METHOD: From March 2000 to July 2004, a retrospective review of 36 patients with tumors of parapharyngeal space with skull base involved and treated surgically procedure was performed. Analyze the clinical characteristics of different tumors of parapharyngeal space with skull base involved. To the various tumors in this series, several surgical approaches were selected: the transcervical (n=15) and transcervical-transparotid approaches (n=10) were the most commonly performed surgical procedures followed by the transmaxillary swing approach (n=5), the transmandible swing approach (n= 4), and transorbitozygomatic-middle fossa approach (n=2). RESULT: In the 36 cases, 5 cases were malignant carcinoma and the others (n=31) were benign. All benign tumors in 31 cases had complete resection with no recurrence. Of the 5 patients with malignant tumors, 2 had SCC (squamous cell carcinoma) of nasopharynx infra-mucous membrane with metastasis in the parapharyngeal space and skull base lesions, after the pathologic identification by the surgical management of transcervical approach, both had undergone post-operative radiotherapy, 1 had disease free with a 3-year follow-up; the other after a follow-up of 5 years, was still alive with disease. Of the other 3 patients, 1 patient with the skull base lesions of malignant neurofibroma had recurrence after a 3-year follow-up, died without therapy at the end; 1 with malignant schwannomas and skull base lesions was alive with no evidence of disease after a follow-up of 2 years; 1 patient with mucoepidermoid carcinoma in deep lobe of parotid gland had operation done 3 months ago, was still under followed. In the 36 cases, post-operative hoarseness occurred in 3 cases; Horner's syndrome occurred in 4 cases; 2 patients had glossal deviation, and it had recovered 3 months later. CONCLUSION: Different tumors of parapharyngeal space with skull base involved have different clinical characteristics. Therefore, we should depend on its characteristics to choose the most appropriate treatment.

[Anatomical landmarks of skull base and safety of the skull base surgery].

OBJECTIVE: In order to improve the safety of skull base surgery and to completely resect the skull base tumors, the anatomical landmarks of skull base were studied. METHODS: 29 cases of skull base surgery were performed between 1992 and 2002, and their clinical data were retrospectively analysed. The anatomical landmarks of cranial base, such as comb, pterygoid process, spine of temporal bone, styloid process, and internal caroid artery, were analysed in preoperative diagnosis and operative treatment of various kinds of skull base tumors. RESULTS: In the early stages, because of lacking the knowledge of anatomical landmarks of the skull base, the surgery lasted longer, part of skull base tumors remained and operative blood lose was much more than that in later stage. In the later stage, no operative death and severe complications were found in 26 cases which underwent various kinds of skull base surgery. The survival rates at 3 and 5 years were 72.2% and 35.7% respectively for malignant tumors. CONCLUSIONS: Comb, pterygoid process, spine of temporal bone, styloid process, internal caroid artery and their adjacent structures were important anatomical landmarks for operative treatment of anterior, middle and lateral cranial base tumors. It was important to know the anatomical landmarks to ensure the safety of the skull base surgery.

[Using PCR method to study the EB virus DNA in NPC].

OBJECTIVE: To study the EB virus DNA distribution in paraffin-embedded tissue, peripheral blood leukocyte and serum in nasopharyngeal carcinoma patients (NPC). METHOD: PCR method, in paraffin-embedded tissue of 39 patients with NPC (NPC group-1) and 20 patients with chronic nasopharyngitis (control group-1), in peripheral blood leukocyte and serum of 24 patients with NPC (NPC group-2) and 10 patients with other head and neck carcinoma (control group-2) and 10 patients with chronic nasopharyngitis (control group-3) were used to test the presence of Epstein-Barr virus DNA. At the same time, we also measured serum EB virus VCA-IgA antibodies with enzyme-immunoassay in NPC group-2, control group-2 and control group-3. RESULT: The results showed that 28 of 39 nasopharyngeal carcinoma patients (71.8%) (NPC group-1) and 3 of 20 chronic nasopharyngitis (15%) (control group-1) were EB virus DNA positive in paraffin-embedded tissues. The difference between NPC group-1 and control group-1 was statistically significant. Ten of 24 NPC group-2 (41.67%) and 1 of 10 control group-2 (10%) were EB virus DNA positive in peripheral blood leukocyte. Control group-3 EB virus DNA was negative in peripheral blood leukocyte. The difference between NPC group-2 and control group-3 was statistically significant (P < 0.05). All of the patients' EB virus DNA were negative in serum. The difference between NPC group-2 and control group-2; 2 was statistically significant in VCA-IgA titer respectively (Ridit Test P < 0.01). CONCLUSION: EB virus DNA positive in paraffin-embedded tissues is higher than that in peripheral blood leukocyte in nasopharyngeal carcinoma patients. In serum EB virus DNA is negative. The results suggest that EB virus DNA positive from paraffin-embedded tissues to peripheral blood leukocyte to serum is decrease gradually. There must be some relationship between VCA-IgA in serum and EB virus DNA in peripheral blood leukocyte.

[Pearson technique in the treatment of advanced laryngeal cancer].

OBJECTIVE: To seek for a better method of treating the advanced laryngeal cancer. METHOD: Twenty-eight cases of advanced laryngeal cancer were treated with near-total laryngectomy(Pearson technique), including 11 glottic cancers(III stage, 8 cases: IV stage, 3 cases), 17 supraglottic cancers (III stage, 13 cases; IV stage, 4 cases). In the same time 26 patients had neck node dissections. All the cases had speech function reconstructions. RESULT: The speech function was obtained in 27/28(96.4%). All cases had good swallowing, 3-year survival rate is 78.6%, 5-year survival rate is 68.4%. CONCLUSION: Near-total laryngectomy can be used in most cases that might be treated with traditional total laryngectomy in the past. It can provide satisfied survival rate, good swallowing, better speech function, but breath function.

[A clinical study on improving phonation function of larynx after partial laryngectomy].

OBJECTIVE: To analyse the clinical results of reconstruction of vocal cord using sternohyoid muscle flap after partial laryngectomy and research a new repairing method to improve laryngeal function and living quality of patient. METHOD: The pronunciation of larynx is on the basic of the vibration of the vocal cord by air current. The laryngeal appearance and the function of opposite side vocal cord is very important for improving the quality of pronunciation. We developed a technique of thyroid cartilage membrane and sternohyoid muscle flap to repair the defect left by a vertical laryngectomy and reconstructed the vocal cord. The thyroid cartilage membrane was used to bridge over the upper part defect of laryngeal cavity, the sternohyoid muscle flap forming the opposite side was made a 90 degree bent toward the laryngeal cavity to repaired the lower part defect of laryngeal cavity and reconstruct a new vocal cord. The repaired larynx recovered the normal appearance. The new vocal cord participated speech. The anterior 2/3 part of both vocal cored could contacted in pronunciation of patient. The phonation function of larynx was restored. RESULT: Sixty-one cases partial laryngectomy was taken including vertical partial laryngectomy in 37 cases, extended vertical partial laryngectomy in 24. During their operations, the laryngeal defect was repaired with thyroid cartilage membrane and sternohyoid muscle flap, and a vocal cord was reconstructed in the same time. After operation, the laryngeal cavity repaired has a normal appearance, and the laryngeal satisfactory phonation effect has been obtained. 93.4% of the patients enjoyed a socially acceptable voice and rejoined normal working. CONCLUSION: A technique of thyroid cartilage and sternohyoid muscle flap to repair the defect and reconstructive vocal cord after partial laryngectomy make patient recover normal laryngeal appearance and obtain satisfactory phonation effect. Among the method of repairation for partial laryngectomy sternohyoid muscle flap should be first considered owing to its various merits: 1. abundant material. 2. convenient procedures. 3. smaller trauma. 4. satisfactory effect.