BACKGROUNDIn prokaryotic organisms, the mechanism responsible for the accurate partition of newly replicated chromosomes into daughter cells is incompletely understood. Segregation of the replication terminus of the circular prokaryotic chromosome poses special problems that have not previously been addressed. The aim of this study was to investigate the roles of several protein components (MreB, MreC, and MreD) of the prokaryotic cytoskeleton for the faithful transmission of the chromosomal terminus into daughter cells.

METHODSStrain LQ1 (mreB::cat), LQ2 (mreC::cat), and LQ3 (mreD::cat) were constructed using the Red recombination system. LQ11/pLAU53, LQ12/pLAU53, LQ13/pLAU53, LQ14/pLAU53, and LQ15/pLAU53 strains were generated by P1transduction of (tetO) 240 -Gm and (lacO) 240 -Km cassettes from strains IL2 and IL29. Fluorescence microscopy was performed to observe localization pattern of fluorescently-labeled origin and terminus foci in wild-type and mutant cells. SOS induction was monitored as gfp fluorescence from PsulA-gfp in log phase cells grown in Luria-Bertani medium at 37°C by measurement of emission at 525 nm with excitation at 470 nm in a microplate fluorescence reader.

RESULTSMutational deletion of the mreB, mreC, or mreD genes was associated with selective loss of the terminus region in approximately 40% of the cells within growing cultures. This was accompanied by significant induction of the SOS DNA damage response, suggesting that deletion of terminus sequences may have occurred by chromosomal cleavage, presumably caused by ingrowth of the division septum prior to segregation of the replicated terminal.

CONCLUSIONSThese results imply a role for the MreBCD cytoskeleton in the resolution of the final products of terminus replication and/or in the specific movement of newly replicated termini away from midcell prior to completion of septal ingrowth. This would identify a previously unrecognized stage in the overall process of chromosome segregation.

Chromosome Segregation ; genetics ; physiology ; Cytoskeleton ; metabolism ; Escherichia coli ; genetics ; metabolism

OBJECTIVE: To investigate the curative effect of electrocorticography (ECoG) monitoring in the microsurgical treatment of cavernous angiomas. METHODS: Clinical data of 71 patients with epileptogenic cavernous angiomas,who had been performed ECoG monitoring during the operation,were analyzed retrospectively. RESULTS: The foci of cavernous angiomas and epilepsy of the 71 patients were resected during the operation. In the 58 patients who were followed up,42 had not epileptic seizure,and 16 still had epileptic seizure,while the frequencies of 13 patients reduced to below 10%,and 3 patients over 10%. CONCLUSION The drug treatment of epileptogenic cavernous angiomas can not control epileptic seizure,and the patients should receive the microsurgical treatment early. Electrocorticography monitoring can direct the surgical procedure,and control the postoperative epileptic seizure.
Adolescent ; Adult ; Cerebral Cortex ; physiopathology ; Electroencephalography ; Epilepsy ; etiology ; Female ; Hemangioma, Cavernous, Central Nervous System ; complications ; surgery ; Humans ; Male ; Microsurgery ; methods ; Middle Aged ; Monitoring, Intraoperative ; methods ; Neurosurgical Procedures ; methods

OBJECTIVETo observe the effect of different concentration of Tamoxifen ointment on the fibroblasts and transforming growth factor (TGF-beta2) of hypertrophic scar at rabbit ears, so as to explore the possibility of treatment of hypertrophic scar with Tamoxifen.

METHODSThe hypertrophic scar model was established in 96 New Zealand rabbits' ears. The wounds were divided into four groups (A, B, C and D), with 144 wounds in each group. Different concentration of tamoxifen ointment (0.5%, 1%, 2%) was topically administered in groups A, B and C respectively, and blank ointment in group D. On postoperative day 30, 60 and 90, the scar samples were harvested. The scar thickness, scar histological change and the content of TGF-beta2 were detected.

RESULTS(1) On the 30th day after operation, the difference of scar tissue thickness among groups A, D and B, C reached statistical significance (group A, D < group B < group C). However, there was a contrary tendency in fibroblasts density and TGF-beta2 content of the scar tissue simultaneously. (2) On 60th, 90th day after injury, there was statistical difference in scar thickness, fibroblasts density and the content of TGF-beta2 in scar of four groups (P < 0.05). The content of TGF-beta2 in group A, B, C, D was (43.97 +/- 3.63) microg/L, (41.92 +/- 3.91) microg/L, (36.69 +/- 4.15) microg/L, (54.90 +/- 4.71) microg/L, respectively, on 60th day; and (45.69 +/- 2.63) microg/L, (40.43 +/- 3.87) microg/L, (38.76 +/- 3.24) microg/L, (52.59 +/- 4.92) microg/L, respectively, on 90th day. The fibroblasts density of scar in groups A, B, C, D was (4392.07 +/- 327.84) point/mm2, (4208.57 +/- 329.76) point/mm2 (4 033.44 +/- 427.91) point/mm2, (4863.03 +/- 387.98) point/mm2, respectively, on 60th day; and (4418.41 +/- 432.52) point/mm2, (4077.65 +/- 386.70) point/mm2, (3844.53 +/- 354.29) point/mm2, (4838.64 +/- 390.52) point/mm2, respectively, on 90th day. The content of TGF-beta2 and fibroblasts density of scar were lined up as group D > group A > group B > group C (P < 0.05).

CONCLUSIONSTopical Tamoxifen can reduce the content of TGF-beta2 and fibroblast, decrease fibroblasts density and the formation of hypertrophic scar at rabbit ears. It offers a new way for the treatment of the hypertrophic scar.

Animals ; Cicatrix, Hypertrophic ; drug therapy ; metabolism ; pathology ; Disease Models, Animal ; Ear Diseases ; drug therapy ; metabolism ; pathology ; Fibroblasts ; drug effects ; pathology ; Ointments ; Rabbits ; Tamoxifen ; pharmacology ; Transforming Growth Factor beta2 ; metabolism

AIMTo investigate the expression of Spindlin 1 (Spin 1) isoform2 and assess its function in mouse testis.

METHODSFirst, reverse-transcription polymerase chain reaction (RT-PCR) was used to determine whether Spin1 isoform2 is present in mouse testis. Then the expression patterns of the isoform between newborn and adult mice testes were compared by immunoblot analysis. Finally, the diversity of its localization in mice testes at different ages (days 0, 7, 14, 21, 28 and 60) was observed by immunohistochemistry. The localization of the protein in mouse sperm was also investigated by immunofluorescence.

RESULTSThe RT-PCR results show that Spin1 isoform2 is present in mouse testis. As shown by immunoblot analysis, the isoform was more highly expressed in adult testes compared with newborn testes. Interestingly, Spin1 isoform2 did not show up in the cytoplasm of primary spermatocytes until day 14. Also, the protein exists at the tail of the mouse sperm.

CONCLUSIONSpin1 isoform2 is a protein expressed highly in adult testis, which might be involved in spermatogenesis and could be necessary for normal sperm motility.

Age Factors ; Animals ; Animals, Newborn ; Blotting, Western ; Cell Cycle Proteins ; genetics ; metabolism ; Cytoplasm ; metabolism ; Female ; Immunohistochemistry ; Male ; Meiosis ; physiology ; Mice ; Mice, Inbred ICR ; Microtubule-Associated Proteins ; genetics ; metabolism ; Phosphoproteins ; genetics ; metabolism ; Pregnancy ; Reverse Transcriptase Polymerase Chain Reaction ; Sperm Motility ; physiology ; Spermatogenesis ; physiology ; Testis ; physiology

Abstract: Objective　To analyze the epidemiological characteristics (season, age, gender, mixed infection and clinical manifestations, etc.) of Mycoplasma pneumoniae (MP) infection in children in Hainan Province, so as to provide epidemiological evidence-based medical basis for the prevention and control of MP infection in children in Hainan Province. Methods　The serum IgM antibodies of MP, Legionella pneumophila, Chlamydia pneumoniae, adenovirus, respiratory syncytial virus (RSV), Q fever Rickettsia, parainfluenza virus, influenza A virus and influenza B virus in children with respiratory tract infections (RTIs) who were hospitalized in pediatrics of many hospitals in Hainan Province from March 2012 to February 2020 were detected by indirect immunofluorescence method. The positive serum MP-IgM antibody was defined as MP infection. The epidemiological and clinical data of MP infected cases were analyzed retrospectively. Results　From March, 2012 to February, 2020, a total of 35 731 qualified pediatric inpatients with RTIs in many hospitals in Hainan Province were tested for serum MP-IgM with the total positive rate of 39.12% (13 978/35 731). The yearly positive rates of MP-IgM from 2012 to 2020 were 48.39%, 56.23%, 56.62%, 47.04%, 29.71%, 24.14%, 47.55%, 36.84% and 24.46% respectively. The positive rates of MP-IgM in 2013 and 2014 were significantly higher than those in other years (P<0.05). The positive rate of MP-IgM in summer in Hainan Province was the highest (41.34%) and the lowest in winter (35.77%) (P<0.05). MP infection occurred in all age groups, the positive rate of MP-IgM in children of preschool (51.80%) was significantly higher than that in other age groups (P<0.01), and the positive rate of MP IgM in children of infancy (15.36%) was lower than that in other age groups (P<0.01). The positive rate of MP-IgM in female was 44.77%, which was significantly higher than that in male (35.83%) (P<0.05). MP infection combined with positive IgM of another pathogen accounted for 32.63% (4 561 cases), positive IgM of another two pathogens accounted for 1.26% (176 cases). MP infection was mostly found in pneumonia (68.73%), and the main clinical symptoms were cough (84.72%), fever (51.01%) and wheezing (3.16%). Conclusions　MP is an important pathogen of respiratory tract infection in children in Hainan Province, and infection is more common in children in early school age and early childhood. Mp-specific tests should be performed to identify the pathogen in children suspected of MP infection. In the high incidence season, health education should be strengthened in kindergartens, schools and other places to prevent respiratory tract infection.

HIV Antibodies ; chemistry ; HIV Infections ; diagnosis ; Humans ; Pharmacies ; Pilot Projects ; Reagent Kits, Diagnostic ; Saliva ; chemistry

Honokiol is an active compound purified from magnolia that has been shown to induce cell differentiation, apoptosis, and anti-angiogenesis effects, as well as an enhancement in tumor growth delay in combination with chemotherapeutic agents in several mouse xenograft models. Our goal was to investigate the radiosensitization effect of honokiol on lung carcinoma. The radiosensitization effect of liposomal honokiol in Lewis lung carcinoma cells (LL/2) was analyzed using an in vitro clonogenic survival assay. For an in vivo study, Lewis lung carcinoma-bearing C57BL/6 mice were treated with either liposomal honokiol at 25 mg/kg or 5 Gy of single tumor radiation, or a combination of both over 12 days of treatment. The tumor growth delay and the survival time were evaluated. In addition, histological analysis of tumor sections was performed to examine changes by detecting the microvessel density and apoptosis in tumor tissues. In the clonogenic survival assay, LL/2 cells treated with IC50 Lipo-HNK for 24 h showed a radiation enhancement ratio of 1.9. After 12 days of combination treatment, the tumor volume decreased 78% and produced an anti-tumor activity 1.3-fold greater than a predicted additive effect of honokiol and radiation alone. This combination treatment also caused an 8.7 day delay in tumor growth. The cell cycle distribution and histological analysis demonstrated that liposomal honokiol has an anti-tumor effect via inducing apoptosis and inhibiting angiogenesis. Liposomal honokiol can enhance tumor cell radiosensitivity in vitro and in vivo, indicating that radiotherapy combined with liposomal honokiol can lead to greater anti-tumor efficacy.
Angiogenesis Inhibitors/administration & dosage/*therapeutic use ; Animals ; Apoptosis ; Biphenyl Compounds/administration & dosage/*therapeutic use ; Carcinoma, Lewis Lung/drug therapy/radiotherapy/*therapy ; Cell Cycle/drug effects/radiation effects ; Cell Line, Tumor ; Combined Modality Therapy ; Humans ; Lignans/administration & dosage/*therapeutic use ; Liposomes ; Lung Neoplasms/drug therapy/radiotherapy/*therapy ; Magnolia/chemistry ; Mice ; Neoplasm Transplantation ; Neovascularization, Pathologic/drug therapy/radiotherapy ; Radiation Tolerance ; Transplantation, Heterologous

Spinal cord stimulation (SCS)-induced analgesia was characterized, and its underlying mechanisms were examined in a spared nerve injury model of neuropathic pain in rats. The analgesic effect of SCS with moderate mechanical hypersensitivity was increased with increasing stimulation intensity between the 20% and 80% motor thresholds. Various frequencies (2, 15, 50, 100, 10000 Hz, and 2/100 Hz dense-dispersed) of SCS were similarly effective. SCS-induced analgesia was maintained without tolerance within 24 h of continuous stimulation. SCS at 2 Hz significantly increased methionine enkephalin content in the cerebrospinal fluid. The analgesic effect of 2 Hz was abolished by μ or κ opioid receptor antagonist. The effect of 100 Hz was prevented by a κ antagonist, and that of 10 kHz was blocked by any of the μ, δ, or κ receptor antagonists, suggesting that the analgesic effect of SCS at different frequencies is mediated by different endorphins and opioid receptors.
Analgesics ; Animals ; Narcotic Antagonists/pharmacology* ; Neuralgia/therapy* ; Opioid Peptides ; Rats ; Receptors, Opioid/physiology* ; Receptors, Opioid, kappa ; Spinal Cord ; Spinal Cord Stimulation

The pain-relieving effect of acupuncture is known to involve primary afferent nerves (PANs) via their roles in signal transmission to the CNS. Using single-unit recording in rats, we characterized the generation and transmission of electrical signals in Aβ and Aδ fibers induced by acupuncture-like stimuli. Acupuncture-like signals were elicited in PANs using three techniques: manual acupuncture (MAc), emulated acupuncture (EAc), and electro-acupuncture (EA)-like peripheral electrical stimulation (PES). The discharges evoked by MAc and EAc were mostly in a burst pattern with average intra-burst and inter-burst firing rates of 90 Hz and 2 Hz, respectively. The frequency of discharges in PANs was correlated with the frequency of PES. The highest discharge frequency was 246 Hz in Aβ fibers and 180 Hz in Aδ fibers. Therefore, EA in a dense-disperse mode (at alternating frequency between 2 Hz and 15 Hz or between 2 Hz and 100 Hz) best mimics MAc. Frequencies of EA output >250 Hz appear to be obsolete for pain relief.

Objective:To investigate the response of mandibular condylar chondroprogenitors to flow fluid shear stress(FFSS).Methods:Chondroprogenitors were in vitro cultured and stimulated with FFSS that can cause cell degeneration,and treated with sec-ond-generation high-throughput RNA sequencing.Differential gene expression was screened using DESeq2 software for gene ontology(GO)functional enrichment analysis,kyoto encyclopedia of genes and genomes(KEGG)pathway enrichment analysis and protein-protein interaction(PPI)network analysis.qRT-PCR was performed to validate the core genes screened by PPI.Results:A total of 1996 differentially expressed genes were obtained,mainly including inflammatory response and cell cycle related molecules.Among them,Actal,Atf3,Ccl2,116,Nfkbia,Ret and Vcaml were identified as the core genes.Conclusion:FFSS stimulation affects chondroprogenitor function by acting on inflammatory responses and cell cycle-related signaling pathways in chondroprogenitors.