Impact of COVID-19 on acute ischemic stroke presentation and prognosis in a county-level stroke center

OBJECTIVE

The COVID-19 pandemic has influenced regular medical procedures and health-seeking behaviors. In this study, we aimed to investigate the influence of the COVID-19 pandemic on the presentation and prognosis of acute ischemic stroke (AIS) patients in county-level stroke centers.

PATIENTS AND METHODS

We retrospectively collected AIS patients during the strict lockdown period (January 24, 2020, to March 27, 2020) and the corresponding "new normal" period (2021) of the COVID-19 pandemic. Patients seen during the same timeframe in 2019 were enrolled as controls. Statistical analysis was conducted to compare the clinical characteristics of AIS patients who presented during the lockdown and new normal periods and those who presented during the pre-COVID-19 pandemic period.

RESULTS

A total of 134 AIS patients presented during the lockdown period (the 2020 group), 207 patients in the pre-COVID-19 period (the 2019 group) and 201 patients in the "new normal" period (the 2021 group). Compared to the 2019 group, there was approximately 1/3 reduction in the number of patients who presented during the lockdown period, while the number of patients who received IVT or EVT was similar between the two groups. The number of patients, baseline characteristics, workflow intervals and clinical outcomes presented during the "new normal" period were similar between the 2019 and 2021 groups. Logistic regression showed that lockdown or new normal status were not risk factors associated with a poor outcome at 90 days.

CONCLUSIONS

In county-level city stroke centers, the COVID-19 lockdown resulted in a reduction in the number of patients with AIS admitted to the hospital but had no effect on patients treated with IVT or EVT. Lockdown or new normal status did not influence the prognosis of AIS patients.

MiRNA-146b-5p inhibits the malignant progression of gastric cancer by targeting TRAF6

OBJECTIVE

MicroRNAs (miRNAs) are 22 nucleotides long that are extensively expressed in eukaryotes. They are vital regulators in pathological processes. This study aims to illustrate the role of miRNA-146b-5p in the development of gastric cancer (GC).

PATIENTS AND METHODS

MiRNA-146b-5p levels in 62 GC species and matched paracancerous ones were detected. Influences of miRNA-146b-5p level on clinical parameters of GC patients were assessed. Phenotype changes of AGS and SGC-7901 cells overexpressing miRNA-146b-5p were evaluated by Cell Counting Kit-8 (CCK-8) and transwell assay, respectively. Luciferase assay and rescue experiments were conducted to uncover the mechanism of miRNA-146b-5p in regulating the development of GC.

RESULTS

MiRNA-146b-5p was downregulated in GC species than paracancerous ones. Lower level of miRNA-146b-5p was observed in GC patients combined lymphatic metastasis and distant metastasis than those without metastases. In vitro overexpression of miRNA-146b-5p attenuated proliferative and migratory potentials of GC cells. TRAF6 was the target of miRNA-146b-5p, which was responsible for the development of GC regulated by miRNA-146b-5p.

CONCLUSIONS

MiRNA-146b-5p level is negatively correlated to lymphatic metastasis and distant metastasis rates of GC. It suppresses the malignant development of GC by targeting TRAF6.

Measures to prevent goggles from fogging during the treatment of Coronavirus Disease 2019

During these challenging and unprecedented times for the global communities as they battle the COVID-19 pandemic, we found a simple and effective way to prevent the goggles fogging. We hope that it will help the healthcare professionals who are still troubled by the problem of fogging goggles.

[Clinical features and recurrence rate on benign paroxysmal positional vertigo]

Objective:To study the characteristics and the recurrence rate of manual reduction of BPPV. Method:The clinical characteristics of 735 patients with BPPV were analyzed retrospectively. The posterior semicircular canal BPPV（PC-BPPV） was treated with the Epley maneuver therapy; the horizontal semicircular canal BPPV（HC-BPPV） was treated with the Barbecue therapy; the anterior semicircular canal BPPV（AC-BPPV） was treated with the Yacovino therapy; the combined semicircular canal was treated with the Epley and the Barbecue therapy; and for the bilateral lesions, first treat the more severe side with manual reduction then the lighter side was treated with manual reduction after the more severe side nystagmus or vertigo completely disappears. Result:①Of the 735 patients with BPPV, 455（61.90%） were PC-BPPV, 272（37.01%） were HC-BPPV, 3（0.41%） were AC-BPPV, and 5（0.68%） were combined BPPV. ②A total of 455 patients with BPPV were followed up by telephone. 51 patients recurred within 3 years, the recurrence rate was 11.21%; the male recurrence rate was 25.68%（38/148）, and the female recurrence rate was 28.66%（88/307）. The recurrence rate was the highest in 51-60 years old, and the recurrence rate was 29.67%. ③300 patients with PC-BPPV were followed up by telephone, 81 cases（27.00%） recurred, and the recurrence rates of one month, six months, one year, two years, and three years were 0.67%（2/300）, 3.33%（10/300）, 6.67%（20/300）, 9.33%（28/300） and 11.67%（35/300） respectively; 155 patients with HC-BPPV were followed up by telephone, 45 cases（29.03%） recurred, the recurrence rates of one months, six months, one year, two years, and three years were 0（0/155）, 2.58%（4/155）, 3.23%（5/155）, 7.10%（11/155） and 9.68%（15/155） respectively. Conclusion:PC-BPPV is the most common disease in BPPV patients. Manual recurrence can effectively treat the recurrence rate of BPPV, female patients is slightly higher than that of male patients. The long-term recurrence rate of PC-BPPV is consistent with that of HC-BPPV. The BPPV were most common in posterior semicircular canal. Manual reduction is effective to treat BPPV cases. BPPV recurrence was not correlated with age and gender. The long-term recurrence rate of PC-BPPV and HC-BPPV is consistent.

[Long-term efficacy observation of BPPV repositioning maneuver]

Objective:The aim of this study is to observe and analyze the long-term follow-up of the recurrence of benign paroxysmal positional vertigo BPPV with repositioning maneuver, and to determine the long-term therapeutic effect of repositioning maneuver. Method:To collect 738 patients who were diagnosed with BBPV due to vertigo. Follow up by telephone, SMS and other contact methods to analyze and summarize the long-term follow up of the recurrence of patients who had been treated with the appropriate repositioning maneuver. Result:Of the 738 patients, 458 patients were followed up and 280 were lost to follow up. The total follow up rate was 62.06%. 458 patients were followed up with 314 patients without recurrence and 144 patients with recurrence. The total recurrence rate was 31.44%. Conclusion:Repositioning maneuver is the most commonly used way for the treatment of BPPV. It is safe, simple and effective. However, patients with BPPV who have been cured by manual reduction still have a risk of recurrence. Among patients with relapse, the proportion of patients who relapsed once after treatment was the highest, and the recurrence rate of women with BPPV was significantly higher than that of men.

[Preliminary study on age stability of VOR gain values of video head impulse test in healthy subjects]

Objective: To explore the age stability of the video head impulse test(vHIT) in healthy subjects. Method: This was a prospective study on healthy subjects referred to our department. One hundred and eighty healthy subjects(age range 21-80) without any current or previous history of brain disorder, vertigo, neck stiffness or eye diseases participated in this study and the vHIT was carried out in all 180 cases. The relationship between VOR gain and age was analysed using univariate regression model and one-way ANOVA for subjects. Result: The VOR gains of the left horizontal semicircular canal, posterior semicircular canal and anterior semicircular canal were 1.02±0.12, 1.04± 0.15 and 0.94±0.16 respectively. The VOR gains of the right horizontal semicircular canal, posterior semicircular canal and anterior semicircular canal were 1.05±0.14, 1.00±0.16, 0.97±0.15 respectively. The difference of VOR gain between left and right corresponding semicircular canals was not statistically significant(P>0.05). For male subjects, the VOR gains of horizontal, anterior and posterior semicircular canal were 1.05±0.13, 1.02±0.16, 0.99±0.16 respectively, and for female subjects, the VOR gains of horizontal, anterior and posterior semicircular canal were 1.05±0.13, 1.01±0.16, 0.97±0.16 respectively. There was no significant difference in VOR gain of three semicircular canals between male and female(P>0.05). The VOR gain in different age groups was analyzed by one-way ANOVA. There was no significant difference in the VOR gain among different age groups(P>0.05). Univariate linear regression analysis was performed between the age and the VOR gain of the three semicircular canals. The slopes of the regression equations were 0.001 8, 0.000 2 and 0.000 3, respectively. Conclusion:The VOR gain of the six semicircular canals in healthy subjects is not significantly influenced by gender, and it varies slightly with age without requirement for adjustment with age. .

[Diffuse pulmonary meningotheliomatosis: a case report and literature review]

Objective: To analyze the clinical features, diagnosis and differential diagnosis of diffuse pulmonary meningotheliomatosis (DPM), a rare subtype of minute pulmonary meningothelial-like nodules (MPMN), so as to improve the understanding of this disorder. Methods: The clinical data of a patient diagnosed as DPM admitted in department of Respiratory Medicine, Peking University Third Hospital in August 2016 were reported and the related literatures were reviewed. With "pulmonary meningothelial-like nodules" , "minute pulmonary meningothelial-like nodules" or "diffuse pulmonary meningotheliomatosis" as the search terms, and the search time before November 1st 2017 for Wanfangdata, China National Knowledge Infrastructure (CNKI), and PubMed.Twenty-five articles were retrieved, among which 6 English (all case reports) articles were found with the search term "diffuse pulmonary meningotheliomatosis" involving 10 cases, and the other 19 articles (1 Chinese, 18 English) about MPMN mainly discussed non-DPM cases,including 13 case reports and 6 pathological/genetic studies. Results: A 68-year old female was admitted to the hospital because of intermittent cough and expectoration for more than 3 years and aggravation for 3 weeks. Her pulmonary CT showed diffuse minute nodules distributed randomly throughout both lungs, and did not improve after treatment with oral Moxifloxacin for 2 weeks. A video-assisted thoracoscopic biopsy was performed. The specimens showed MPMN and no other lesions, which confirmed the final diagnosis of DPM. She was followed without any medication therapy and her pulmonary CT showed stabilization of the lesions one year later. DPM was considered as a rare type of MPMN. A total of 11 cases were analyzed, including 10 cases reported in the literature. The patients included 1man and 10 women, aged 51 to 75 years, with an average age of (64±8) years. Among the 11 patients, 8 denied a history of smoking or of occupational exposure, 7 presented with dyspnea, shortness of breath, or fatigue, and 8 had mild abnormalities of pulmonary function test. The pulmonary CT of all the patients showed randomly distributed, diffuse bilateral small solid or ground-glass nodules, with the diameters less than 5 millimeters, some of which were cavitated. Only 1 patient had pulmonary thromboembolism, while the other 10 did not have any other lung diseases. All the patients were histologically diagnosed, 8 by open lung biopsies, 2 by transbronchial lung biopsy, and 1 by CT-guided fine needle aspiration. Three patients were followed for 12-92 months and the lung lesions were all stable. Conclusions: As a rare subtype of MPMN, DPM lacks specificity of clinical manifestations, and presents with diffuse bilateral small solid or ground-glass nodules, distributed randomly throughout both lungs. An early correct diagnosis depends on biopsy.

[Risk factors and sonographic findings associated with the type of placenta accreta spectrum disorders]

Objective: To evaluate the risk factors and sonographic findings of pregnancies complicated by placenta increta or placenta percreta. Methods: Totally, 2 219 cases were retrospectively analyzed from 20 tertiary hospitals in China from January 2011 to December 2015. The data were collected based on the original case records. All cases were divided into two groups, the placenta increta (PI) group (79.1%, 1 755/2 219) and the placenta percreta (PP) group (20.9%, 464/2 219) , according to the degree of placental implantation. The risk factors and sonographic findings of placenta increta or percreta were analyzed by uni-factor and logistic regression statistic methods. Results: The risk factors associated with the degree of placental implantation were age, gravida, previous abortion or miscarriage, previous cesarean sections, and placenta previa (all P<0.05), especially, previous cesarean sections (χ(2)=157.961) and placenta previa (χ(2)=91.759). Sonographic findings could be used to predict the degree of placental invasion especially the boundaries between placenta and uterine serosa, the boundary between placenta and myometrium, the disruption of the placental-uterine wall interface and loss of the normal retroplacental hypoechoic zone(all P<0.01). Conclusions: Previous cesarean sections and placenta previa are the main independent risk factors associated with the degree of placenta implantation. Ultrasound could be used to make a prenatal suggestive diagnosis of placenta accreta spectrum disorders.

[Clinical analysis of candidemia in immunocompetent patients]

OBJECTIVE

To investigate the etiological and clinical characteristics of immunocompetent patients with candidemia.

METHODS

The clinical and microbiological data of patients diagnosed as candidemia admitted in Peking University Third Hospital from January 2010 to June 2016 were retrospectively analyzed. Underlying diseases, Candida spp. colonization, clinical manifestations, microbiological data, treatment and the outcome were compared between the HIV-negative immunocompromised (IC) and nonimmunocompromised (NIC) patients.

RESULTS

A total of 62 cases diagnosed as candidemia were analyzed including 36 men and 26 women, with 16 to 100 years of age [(66.02±17.65) years]. There were 30 NIC and 32 HIV-negative IC patients respectively. In the NIC patients, there were 19 cases (19/30, 63.33%) with admission in intensive care unit (ICU), 21 (21/30, 70.00%) associated diabetes mellitus or uncontrolled hyperglycemia and 22 (22/30,73.33%) receiving invasive mechanical ventilation, while in the HIV-negative IC patients, there were 8 (8/32, 25.00%), 13 (13/32, 40.63%) and 7 (7/32, 21.88%) respectively (P<0.05). The NIC patients had higher acute physiology and chronic health evaluation (APACHE II) scores and sequential organ failure assessment (SOFA) scores both at admission (19.98±5.81, 6.04±6.14) and candidemia onset (25.61±6.52, 12.75±8.42) than the HIV-negative IC patients (APACHEII 15.09±5.82, 22.15±5.98) and SOFA 2.87±2.73, 7.66±5.64 respectively (P<0.05). In the NIC patients, twenty-one cases (21/30, 70.00%) died in hospital, while 14 cases (14/32, 43.75%) in HIV-negative IC. The crude mortality was significantly different between the two groups (P<0.05). By blood culture, Canidia albicans remained the the most prevalent isolates in all the patients. Clinical manifestation, Candida spp. colonization, etiology and drug susceptibility were also similar between NIC and HIV-negative IC patients (P>0.05).

CONCLUSION

Candidemia in NIC patients tends to occur in those who are much more critically ill, more often admitted in ICU, and more frequently have diabetes mellitus or uncontrolled hyperglycemia and receive invasive mechanical ventilation than HIV-negative IC patients. NIC patients also have poorer prognosis than HIV-negative IC patients. Clinical manifestations, and microbiological characteristics are similar between HIV-negative IC and NIC patients.

[Retrospective analysis of factors affecting patency rates and causes of failure in use of single-armed two-suture microsurgical vasoepididymostomy]

Objectives: To analyze the factors affecting the patency rate of microsurgical single-stitch longitudinal intussusception vasoepididymostomy and to explore the possible causes of failure. Methods: The clinical data of 87 patients with epididymal obstructive azoospermia who underwent microsurgical vasoepididymostomy from January 2015 to February 2018 in the First Affiliated Hospital of Fujian Medical University were analyzed retrospectively. We observed the patency rate postoperatively and evaluated several factors that possibly related to the patency rates. Preoperative examinations included peripheral blood chromosomes, Y chromosome microdeletions, sex hormones, seminal plasma, etc. After admission, microsurgical single-stitch longitudinal intussusception vasoepididymostomy was performed. During the follow-up, the semen was evaluated to assess the patency rate and the time to patency. Results: The patient's age ranged from 21 to 42 years and the mean age was(25±3) years. Infertility lasted for 1-8 years and the mean infertility time was(2.2±1.1) years. The longitudinal intussusception vasoepididymostomy was successfully completed in 80 patients , 5 cases gave up the anastomosis surgery because of multiple segment obstruction of the vas deferens, complete obstruction of the epididymis or testicular obstruction. Two cases underwent crossed vasovasostomy( sperm was present in the ejaculate in 1 case postoperatively). Of all the patients, 72 were successfully followed up. The follow-up time was 3-29 months, with an average of (12.0±1.7)months. Excluding 3 cases of follow-up time less than 12 months who still had no sperm in the ejaculate, 69 patients' data were in cluded in the final statistics, of which 50 cases with return of sperm in the ejaculate, the overall patency rate was 72.5%(50/69), concentration of sperm was 0.1-137.2 million/ml, and the mean concentration was(29±21) million/ml; with the progressive motile sperm rate ranging from 0-57.9%, the mean rate was(29.9±21.1)%. The patency rates of motile sperm and immobile sperm found in epididymal fluid during surgery were 82.2%(37/45) and 54.2%(13/24), respectively. The patency rate of bilateral and unilateral anastomoses was 77.6%(45/58) and 45.5%(5/11), respectively; the patency rate of caput anastomosis was 47.8%(11/23), and 84.8%(39/46) for corpus or caudal anastomosis. 17 patients achieved natural pregnancy postoperatively, the rate was 34.0%(17/50). Conclusions: The therapeutic effect of microsurgical single-stitch longitudinal intussusception vasoepididymostomy is satisfactory. The motile spermatozoa in epididymal fluid, bilateral surgery and corpus or caudal anastomosis can improve the patency rate postoperatively.

Meta-analysis of the association of IGFBP3 and IGF1 polymorphisms with susceptibility to colorectal cancer

The aim of this study is to comprehensively evaluate the associations of IGFBP3 and IGF1 polymorphisms with susceptibility to colorectal cancer (CRC). We searched the English and Chinese databases and recruited case-control studies based on strict inclusion and exclusion criteria. The statistical analysis was performed by the Comprehensive Meta-analysis 2.0 (CMA 2.0) software and this initially identified 251 studies. We then recruited 10 English studies to this meta-analysis detailed review which includes 9,415 CRC patients and 14,179 healthy controls. Our results demonstrated that IGFBP3 rs2854746 C>G polymorphism increases susceptibility to the CRC (allele model: OR=1.167, 95% CI=1.095~1.244, p<0.001 and to the dominant gene model: OR=1.226, 95% CI=1.113~1.350, p<0.001); but IGFBP3 rs2854744 A>C has no significant association with the CRC susceptibility (allele model: OR=0.970, 95% CI=0.932~1.010, p=0.138; dominant gene model: OR=0.995, 95% CI=0.936~1.057, p=0.874). Also, IGF1 rs35767 C>T polymorphism decreases susceptibility to CRC (allele model: OR=0.785, 95% CI=0.726~0.850, p<0.001 and also the dominant model: OR=0.730, 95% CI=0.661~0.806, p<0.001). However, IGFBP3 rs2854746 C>G is considered the susceptible CRC polymorphism and IGF1 rs35767 C>T is CRC protective.

[Effectiveness of transurethral seminal vesiculoscopy in the treatment of persistent hematospermia, and oligoasthenozoospermia and azoospermia from ejaculatory duct obstruction]

Objective: To analyze the effectiveness of transurethral seminal vesiculoscopy in the treatment of persistent hematospermia, and oligoasthenozoospermia and azoospermia from ejaculatory duct obstruction. Methods: The clinical date of 56 cases of persistent hematospermia, or azoospermia/oligoasthenozoospermia from ejaculatory duct obstruction treated with transurethral seminal vesiculoscopy between November 2013 and January 2016 in the First Affiliated Hospital of Fujian Medical University were reviewed. A total of 30 cases were persistent hematospermia for 6 months to 3 years, with no response to routine antibiotic therapy for >4 weeks; 24 cases were obstructive azoospermia; and the other 2 cases were extreme oligoasthenozoospermia. Transrectal ultrasound of the prostate and seminal vesicles, and pelvic magnetic resonance imaging (MRI) were performed before the surgery, finding seminal vesicle dilation in 28 cases, ejaculatory duct dilation in 18 cases, seminal vesicle and ejaculatory duct dilation in 7 cases, seminal vesicle dilation with ejaculatory duct cyst in 2 cases, and bilateral ejaculatory duct dilation with prostatic utricle cyst in 1 case. After the transurethral seminal vesiculoscopy, follow-up examinations were performed to assess the effectiveness of the surgery for ≥3 months. Results: The surgery was successful in all the patients, with the duration of surgery ranging from 30 to 148 minutes. Among the 30 patients with hematospermia, calculi in ejaculatory duct or seminal vesicle was found in 20 cases, while inflammation or dark red jelly-like substances in seminal vesicle was seen in all cases. In the follow-up of 9.7 months (3.0-13.0 months), hematospermia in 26 (26/30, 86.7%)patients was relieved or cured after 1-6 times of ejaculation; the other 4 (4/30, 13.3%)cases still had hematospermia. In postoperative semen analysis for the 24 cases of azoospermia from ejaculatory duct obstruction, sperms were detected in 16(16/24, 66.7%)cases, but sperms were not found after 6 months following the surgery in 1 of the 16 case, thus re-obstruction was suspected; in the other 8 (8/24, 33.3%)cases, sperms could not be found in multiple semen analyses in >12 months after the surgery. The 2 cases of extreme oligoasthenozoospermia had obvious improvement in routine semen analysis in 1 and 3 months after the surgery. Except for 1 case of scrotum swelling after surgery, no postoperative complications (retrograde ejaculation, urinary incontinence, or rectal injury) were observed. Conclusions: Transurethral seminal vesiculoscopy was an effective therapy for persistent hematospermia. More strict operation indication and careful performance are necessary for azoospermia oligoasthenozoospermia from ejaculatory duct obstruction.

Detection of quantitative trait loci for kernel oil and protein concentration in a B73 and Zheng58 maize cross

Maize (Zea mays L.) is one of the most important food crops throughout the world, and provides oil and proteins to humans and livestock. Kernel oil and protein content in maize are two complex quantitative traits. In order to identify quantitative trait loci (QTL) controlling oil and protein concentration in maize kernels, and to evaluate their genetic effects, QTL analysis was conducted on an F3:4 population derived from a cross between an inbred line with a low oil and protein concentration (Zheng58) and an inbred line with a higher oil and protein concentration (B73). A total of 189 polymorphic simple sequence repeat markers were used to construct a linkage map. Eleven QTLs for kernel oil concentration were detected on nine chromosomes, except for chromosome 9. A single QTL explained 4.6 to 11.1% of the phenotypic variance. Ten QTLs for kernel protein concentration were also detected on nine chromosomes, except for chromosome 9. A single QTL explained 4.2 to 11.4% of the phenotypic variance. Interestingly, novel QTLs for oil concentration (qOIL08-01 and qOIL10-01) and QTLs for protein concentration (qPRO01-01 and qPRO05-01) were specific to the population studied, which could explain 7.1 to 11.1% of the phenotypic variance. These results will provide better understanding of the genetic basis of oil and protein concentrations in maize. The markers closely linked with the QTLs will facilitate breeding of maize varieties with high oil and protein concentrations through molecular marker-assisted selection.

A novel HLA-DRB1 allele, DRB1*16:36 identified in a Chinese individual from the Xinjiang region

A novel class II human leukocyte antigen allele HLA-DRB1*16:36 is described.

Lactulose oral solution for the treatment of postpartum constipation

The purpose of this study is to explore the effectiveness and safety of lactulose oral solution in treating puerperal constipation. The lactulose group was given lactulose, 15 ml once a day, and then given a maintenance dose of 5 ~ 15 ml/time according to defecation condition of patients. Maintenance treatment lasted for one week if the symptoms were relieved; but once symptoms recurred, the medication was restored. Patients in the control group were blank controls. The treatment lasted for six weeks. The conditions of patients, adverse events and combined medication were recorded every day. Patients were evaluated with SF-36 scale before and after treatment. Two hundred and eleven patients with postpartum constipation were selected from five research institutes and they were divided into lactulose group (n=106) and control group (n=105). The curative effect and the improvement of symptoms of the lactulose group were much better than those of the control group (p less than 0.01). Constipation in the lactulose group relieved faster compared to the control group (p less than 0.05). Number of days without constipation in the lactulose group was much more than that of the control group (p less than 0.05). Defecation time in the lactulose group was shorter than that of the control group (p less than 0.05). Dose of lactulose in the lactulose group reduced week by week. Differences of general physical conditions in SF-36 scale between two groups were statistically significant (p less than 0.05). Various vital signs of the two groups had no significant changes after treatment. It can be concluded that, lactulose is an effective and safe drug for treating postpartum constipation.

Current status and recent advances of next generation sequencing techniques in immunological repertoire

To ward off a wide variety of pathogens, the human adaptive immune system harbors a vast array of T-cell receptors (TCRs) and B-cell receptors (BCRs), collectively referred to as the immune repertoire. High-throughput sequencing (HTS) of TCR/BCR genes allows in-depth molecular analysis of T/B-cell clones, providing an unprecedented level of detail when examining the T/B-cell repertoire of individuals. It can evaluate TCR/BCR complementarity-determining region 3 (CDR3) diversity and assess the clonal composition, including the size of the repertoire; similarities between repertoires; V(D)J segment use; nucleotide insertions and deletions; CDR3 lengths; and amino acid distributions along the CDR3s at sequence-level resolution. Deep sequencing of B-cell and T-cell repertoires offers the potential for a quantitative understanding of the adaptive immune system in healthy and disease states. Recently, paired sequencing strategies have also been developed, which can provide information about the identity of immune receptor pairs encoded by individual T or B lymphocytes. HTS technology provides a previously unimaginable amount of sequence data, accompanied, however, by numerous challenges associated with error correction and interpretation that remain to be solved. The review details some of the technologies and some of the recent achievements in this field.

In vitro study on the influence of strontium-doped calcium polyphosphate on the angiogenesis-related behaviors of HUVECs

Angiogenesis is of great importance in bone tissue engineering, and has gained large attention in the past decade. Strontium-doped calcium polyphosphate (SCPP) is a novel biodegradable material which has been proved to be able to promote in vivo angiogenesis during bone regeneration. An in vitro culture system was developed in the present work to examine its influence on angiogenesis-related behaviors of human umbilical vein endothelial cells (HUVECs), including cell adhesion, spreading, proliferation and migration. The effects of microtopography, chemical property and the ingredients in the degradation fluid (DF) on cell behaviors were discussed. The results showed that cells attached and spread better on SCPP scaffold than on calcium polyphosphate (CPP), which might partially result from the less rough surface of SCPP scaffold and the less hydrogel formed on the surface. In addition, cell proliferation was significantly improved when treated with SCPP DF compared with the treatment with CPP DF. Statistical analysis indicated that Sr(2+) in SCPP DF might be the main reason for the improved cell proliferation. Moreover, cell migration, another important step during angiogenesis, was evidently stimulated by SCPP DF. The improved in vivo angiogenesis by SCPP might be assigned to its better surface properties and strontium in the DF. This work also provides a new method for in vitro evaluation of biodegradable materials' potential effects on angiogenesis.

[Aneurysmal model induced by elastase]

OBJECTIVE

To induce the aneurysms by corrosion of aneurysmal wall with elastase, imitating clinical intracranial aneurysms patho-morhologically.

METHODS

The elastase-corroded arterial segments were transplanted onto lateral walls of carotid arteries. Follow-up and pathological examination of the aneurysms were made at two weeks and one month after construction.

RESULTS

The aneurysms formed by the transplantation of elastase-corroded arterial segments were found persistent or enlarge a little within one month. The aneurysms were purplish red and easy to rupture when exposed. The walls were deprived of elastic layer, and constructed by thin connective tissue.

CONCLUSIONS

The aneurysms made by transplanting elastase-corroded arterial segments are simple to built, while morphological and pathological characteristics are demonstrated good clinical mimicry, we believe our aneurysm model may well substitute the most popularly used aneurysms made of venous pouches.

Cellular source, activation and inhibition of dental plaque collagenase

Dental plaque is the major aetiological factor in periodontal diseases and contains several proteolytic enzymes. The origin of these proteinases is, however, poorly studied. This study was undertaken to characterize collagenase present in dental plaque of adult periodontitis patients. Vertebrate-type rather than bacterial-derived collagenase activity was detected in extracts of both supra- and subgingival dental plaque extracts of adult periodontitis patients. Dental plaque collagenase was found to exist predominantly in autoactive form. Dental plaque collagenase from periodontally healthy individuals existed in latent from. Latent dental plaque collagenase from periodontitis lesions could be activated by a 95 kD chymotrypsin-like proteinase from Treponema denticola and human leukocyte cathepsin G but not by human plasmin. Incubation of purified latent leukocyte collagenase with whole cells of Fusobacterium nucleatum, Eubacterium saburreum, Prevotella buccae and Porphyromonas gingivalis, however, did not result to the activation of the enzyme. Doxycycline in vitro inhibited dental plaque collagenase with an IC50-value of 20 microM. Dental plaque collagenase degraded more efficiently type I and II collagens than type III collagen. Western-blot analysis with specific anti-human neutrophil collagenase-antibody revealed that both in supra- and subgingival dental plaque extracts dental plaque collagenase had undergone proteolytic conversion from an 80 kD proform to a 58 kD active form which is associated with catalytic autoactivity as measured by functional collagenase assay. This reflects proteolytic activation of leukocyte collagenase in dental plaque probably by other proteases derived from potent periodontopathogenic bacteria such as T. denticola or other PMN proteases such as cathepsin G.(ABSTRACT TRUNCATED AT 250 WORDS)

Limulus hemocyte transglutaminase. Its purification and characterization, and identification of the intracellular substrates

To investigate further the molecular events of the intracellular coagulation cascade in limulus hemocytes, a transglutaminase (TGase), which may be involved in the formation of a stabilized gel, was purified and characterized. Through the purification procedures consisting of six steps, 1.6 mg of TGase with a specific activity of 940 amine incorporation unit/mg was obtained from 32.4 g of Tachypleus tridentatus hemocytes. The purified TGase gave a single band on SDS-polyacrylamide gel electrophoresis with a molecular mass of 86 kDa, and demonstrated mammalian-type II TGase-like enzymatic properties. The TGase activity was Ca(2+)-dependent and was inhibited by primary amines, EDTA, and SH-reagents. Moreover, two major potential substrates for TGase were identified in the hemocyte lysate by using dansylcadaverine (DCA) incorporation in the presence of 10 mM CaCl2 and 10 mM dithiothreitol. Of these protein substrates, an 80-kDa protein contained a large number of proline residues, amounting to about 22% of the total amino acids. On the other hand, an 8.6-kDa protein abundantly present in the hemocytes was characterized as a Cys-rich protein consisting of 81 amino acid residues and a calculated molecular mass of 8,671. The entire amino acid sequence of this protein was established. Also, the 8.6-kDa protein was readily cross-linked intermolecularly by TGase, forming multimers as large as pentamers. We speculate that like plasma factor XIIIa, limulus TGase and its two protein substrates in the hemocytes may play an important role in the defense of this animal against invading microorganisms.

Extensive scalds following accidental immersion in hot water pools

The scalds produced by immersion in hot water pools were extensive, usually of superficial depth on the upper parts of the body and deep dermal or full thickness skin loss on the lower parts. Blisters appeared rather slowly, within 2 days post-burn and often dispersed spontaneously. The estimated burned area on admission may thus be smaller than found subsequently. This study showed that the volume of fluid required for adequate resuscitation during the first post-burn day may be only 1.5 ml/kg/% BSA burned. Deep dermal burns were treated preferably by early tangential excision and grafting. The full thickness skin loss was treated by escharectomy and skin grafts.

Clinical and histological observations on the application of intermingled auto- and porcine-skin heterografts in third degree burns

Escharectomy and skin grafting with both homograft and porcine skin has become an effective method in treating massive third degree burns. Seventeen patients and 21 operations of intermingled transplantation of auto- and fresh porcine skin heterografts after escharectomy of the severe burn wounds have been carried out since March 1973. Clinical and histological data are summarized, among which we observed the 'fusing phenomena' of auto- and porcine skin heterografts in 6 patients. Vascularization, 'turning red', viability and rejection as well as ways to improve the results of the grafting method are discussed. No vascular communication between fresh porcine skin and the host wound has been observed during the early postoperative period. The cause of 'turning red' is a reddish transudation between the graft and the host wound seen through the thin porcine skin. Based on histological observations, porcine skin is viable after transplantation. With nutritional support apparently coming from the underlying plasma and tissue fluid. Eventually the process of rejection is similar to that of homograft Better results are found with porcine skin grafts 0.4-0.5 mm in thickness placed 0.5-0.75 cm apart. In order to avoid large sloughing wound surfaces less than 20 per cent area of porcine skin coverage is advisable.