Human cytomegalovirus(HCMV)infection is quite prevalent in population. HCMV triggers important disorders in pregnant women,immune-compromised individuals and organ-transplant patients. For dec-ades,more and more scholars believe that NK cells are important immune cells against HCMV. The activity of NK cells largely depends on the balance between the signals transducted by inhibitory receptors and activatory re-ceptors,therefore the study of NK receptors is of great importance. It may be helpful to the basic research and clinical treatment of HCMV infection. Here,this paper reviews the changes and the molecular mechanism of NK receptors in the control of HCMV infection.

Objective To explore the effects of low molecular weight heparin (LMWH) on the virological and pathological changes of newborn mouse liver congenitally infected with human cytomegalovirus (HCMV).Methods Sixty healthy pure line clean level BALB/c mice which were about 10 weeks old (half were female) were divided into five groups (six pairs in each group).The mice in LMWH intervention group and positive control group were intraperitoneally inoculated with 6.0 lg tissue culture infective dose50 (TCID50) of HCMV AD169; those in blank control group were intraperitoneally injected with 0.5 mL dulbecco's modified Eagles medium (DMEM) ; then all the mice were paired to mate.The pregnant mice in LMWH intervention group Ⅰ were subcutaneously injected with LMWH 1000 U/kg daily for 10 days; those in group Ⅱ were subcutaneously injected with LMWH 1000 U/kg daily for 5 days and their newborn mice were subcutaneously injected with LMWH 1000 U/kg daily for 5 days; those in group Ⅲ were subcutaneously injected with LMWH 1000 U/kg daily for 10 days in their newborn mice.All these newborn mice were sacrificed at day 10 of birth.The liver was removed for virus isolation,dry-wet weight determination,pathology examination and quantitative fluorescence-polymerase chain reaction (PCR) detection.The comparison among groups was done by analysis of variance.Results HCMV was isolated from the supernatant of liver tissue homogenate in 10-day positive control newborn mice,while HCMV was isolated in 24-day newborn mice of the other three groups of LMWH intervention.Pathology confirmed that positive control liver tissue had inflammatory changed,liver cell inflammatory swelling degeneration,vacuoles degeneration,specific HCMV inclusion body in nuclear,and portion of liver cell necrosis,while liver pathological results of LMWH intervention group showed mild liver cell inflammatory changes and slight cell inflammatory swelling degeneration,which were similar to the blank control group.The moisture of liver tissue contents in LMWH intervention group decreased more obviously than positive control group.The HCMV DNA loads in 50 mg liver tissues of LMWH intervention groups Ⅰ,Ⅱand Ⅲ were (3.26±0.43),(3.26±0.41) and (3.32±0.51) lg copy,respectively,which were significantly lower than that of positive control group [(7.38 ± 0.53) lg copy; F =314.620,P0.01],while there were no significant differences among LMWH intervention groups (P＞0.05).Conclusion LMWH intrauterine and postnatal interventions can significantly reduce HCMV DNA replication in hepatocytes,and relieve inflammatory changes in liver tissue.

Objective To explore the best vibration frequency for activating human muscles.Methods Nineteen healthy college students accepted vibration stimulation at frequencies between 10 and 50 Hz.Surface electromyograms (sEMG) were recorded.The subjects were sitting,standing,squatting (knee flexion 30°) and recumbent.Their left anterior tibial muscles and the medial heads of the gastrocnemius were targeted as test muscles.The vibration stimulation point was on the surface of the left distal tibia.The sEMG characteristics of the calf muscles were analyzed under vibration stimulation at different frequencies. ResultsThe leg muscles were activated significantly at all vibration frequencies,but the sEMG values of the anterior tibialis were significantly different at different frequencies,except for among 30 Hz,40 Hz and 50 Hz in any position.The gastrocnemius sEMG values were not significantly different at different frequencies. ConclusionVibration at 30 to 50Hz may be the normal human muscle activation frequency.

At present, nucleic acid testing technology has been widely used in clinical laboratory diagnosis. Conventional detection technique such as real-time PCR is complicated, time consuming, and dependent on specific instruments. Clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR associated protein (Cas) system is an adaptive immune defense system against viruses in bacteria and archaea, which has been developed into a powerful technology for genome editing. Recently, the leading groups engaged in CRISPR have set up new tools for nucleic acid detection based on Cas13a, Cas12a and newly discovered protein-Cas14, which plays an important role in rapid diagnosis of infectious diseases, detection of gene mutations in cancer and genotyping. Since they are ultrasensitive, specific, rapid and cost-effective, it is expected to bring great potential for molecular diagnosis. In this review, the mechanism of CRISPR/Cas system and the principle, the applications of the newly-developed diagnostic platforms are introduced. What′s more, the advantages, limitations and prospects of the technologies are summarized.

Objective To explore whether the stimulation effect of high phosphate on hyperplasia of human parathyroid cells and hyperparathyroidism through local cyclooxygenase 2 (COX2) up-regulation pathway. Methods Parathyroid glands were collected from 19 uremic patients undergoing parathyroidectomy.Expressions of COX1,COX2 and proliferative cell nuclear antigen (PCNA) of the glands were detected by immunohistochemistry.Primary parathyroid cells were cultured and treated with high or normal phosphate for 48 hours.Then expressions of COX2 and PCNA were detected by Western blotting and real-time PCR. Results Among 62 glands from above 19 patients,43 glands were nodular hyperplasia and 19 diffuse hyperplasia.Both high expressions of COX2 and PCNA were found in these blands.Expression of COX2 was found in both oxyphil and chief cells and was more in the diffuse hyperplasia glands than that in the nodular hyperplasia (P＜0.05).80.60％ and 85.20％ of COX2 positive cells in diffuse hyperplasia glands and nodular hyperplasia also expressed PCNA. High phosphate could stimulate iPTH secretion in vitro (P＜0.05).Expressions of COX2 and PCNA were higher in high phosphate group.(P＜0.05). Conclusion High phosphate may stimulate the hyperplasia of parathyroid cells by up-regulating the local COX2 expression.

Objective To investigate the influencing factors of epileptic seizure in chronic renal failure (CRF) patients.Methods CRF patients,admitted to our hospital from March 2014 to October 2018,were chosen in our study,and divided into epilepsy group (n=40) and non-epilepsy group (n=3653) according to whether the patients were with or without epilepsy.Clinical data,as length of hospital stays,dialysis methods,presences of infection,sites of infection,and use of antibiotics,and laboratory variables,as blood routine examination,straw aminotransferase (AST),and alanine aminotransferase (ALT),were collected and retrospectively analyzed.Logistic regression analysis was used to determine the independent factors affecting seizures in patients with CRF.Results The patients in the epilepsy group had significantly longer duration of dialysis and length of hospital stays,statistically higher incidence of infection and proportion of dialysis,and significantly worse prognosis than the patients from non-epilepsy group (P＜0.05).The leukocyte count of the epilepsy group was significantly higher than that of the non-epilepsy group,the contents of hemoglobin,ALT and albumin were significantly lower than those of the non-epilepsy group,and the contents of urea nitrogen,creatinine and serum potassium were significantly higher than those of the non-epilepsy group (P＜0.05).Logistic regression analysis showed that epilepsy was associated with serum potassium,creatinine,urea nitrogen and dialysis.Conclusion The etiology of epilepsy is complex,which is related to dialysis,toxin levels,and electrolyte imbalance;the mortality rate of those patients is high and the prognosis is not good.

Objective:To evaluate the effect of web-based problem-based learning software on the Clinical Medicine PBL Comprehensive Course. Methods:Thirty-eight students from the pilot class of undergraduate excellent doctors in clinical medicine were selected as the research objects. Based on the test scores of web-based problem-based learning software before the start of the course, the improvement of scores after passing the training of the Clinical Medicine PBL Comprehensive Course were compared, and the students' clinical thinking were quantitatively evaluated. Results:After all students completed the course, their abilities of expression and communication, teamwork and cooperation, problem analysis and clinical reasoning, and knowledge information management of the students increased steadily with the increase in the number of cases, but it was statistically significant after two PBL case trainings ( P<0.05). Learning intentions and attitudes scored the highest in the second PBL case (acute myocardial infarction), with statistical differences ( P<0.05). After training through the PBL course, diagnostic performance, clinical thinking, treatment scores, and overall performance scores of the students were significantly increased than before, with statistical significance ( P<0.05). The scores of case report writing and knowledge acquisition were not obviously improved. Conclusion:The combination of formative evaluation and web-based problem-based learning software can better evaluate the teaching effect and help students to understand their own shortcomings.