[Properties of gelatin-polyethylene glycol hydrogel loaded with silver nanoparticle Chlorella and its effects on healing of infected full-thickness skin defect wounds in mice]

Objective: To explore the properties of gelatin-polyethylene glycol hydrogel loaded with silver nanoparticle (AgNP) Chlorella (hereinafter referred to as the composite hydrogel) and its effects on healing of infected full-thickness skin defect wounds in mice. Methods: The research was an experimental research. The simple gelatin-polyethylene glycol hydrogel (hereinafter referred to as the simple hydrogel) and the composite hydrogel were prepared, and the appearance and injectability of the two hydrogels were observed at 55 and 37 ℃, and under the irradiation of 808 nm near-infrared light, respectively. An electronic universal testing machine was employed to assess the tensile and compressive stress-strain properties of both types of hydrogels at room temperature. Additionally, the cyclic compressive stress-strain properties of the composite hydrogel were examined at 80% of the maximum compressive stress. Staphylococcus aureus or Escherichia coli solution was added to phosphate buffer solution (PBS), simple hydrogel, and composite hydrogel, respectively. The part of composite hydrogel containing Staphylococcus aureus or Escherichia coli solution was irradiated with near-infrared light for 5 minutes. After each sample was incubated for 6 h, the dilution plating method was used to detect and calculate the mortality rates of the two bacteria at 24 h of culture (n=5). The discarded foreskin tissue was taken from a 6-year-old healthy boy admitted to the Department of Urology of the First Affiliated Hospital of Naval Medical University for circumcision. Primary human fibroblasts (HFbs) were isolated using the enzyme extraction method, routinely cultured to the 3rd to 6th passages for subsequent cellular experiments. Composite hydrogel extracts with final mass concentrations of 100.0, 50.0, 25.0, 12.5, and 0 mg/mL were respectively prepared and used to culture HFbs, and the cell proliferation after 24 h of culture was detected using a cell counting kit 8 (n=3). A total of twenty 6-8 weeks old C57BL/6J female mice were utilized, and a full-thickness skin defect was surgically created on the back of each mouse. The wounds were infected with Staphylococcus aureus solution. The infected mice were divided into blank control group, simple hydrogel group, composite hydrogel group, and combined treatment group according to the random number table, and the wounds were treated with PBS, simple hydrogel, composite hydrogel, and composite hydrogel+light irradiation (under the irradiation of 808 nm near-infrared light for 5 min), respectively, with 5 mice in each group. On post injury day (PID) 0 (immediately after the first wound treatment), 3, 7, and 14, an overall assessment of wound exudation and healing were conducted, and the wound healing rates on PID 7 and 14 were calculated (n=5). On PID 14, hematoxylin-eosin staining was performed to observe histopathological changes in the mouse wound. Results: Both simple hydrogel and composite hydrogel were in a solution state at 55 ℃ and transition to a gel state when cooling to 37 ℃. After the two hydrogels were irradiated by near-infrared light, only the composite hydrogel reheated up and returned to the solution state again with injectability. The maximum tensile stress of the composite hydrogel was up to 301.42 kPa, with a corresponding strain of 87.19%; the maximum compressive stress was up to 413.79 kPa, with a corresponding strain of 91.67%, which was similar to the tensile and compressive properties of the simple hydrogel. After 10 compression cycles, the maximum compressive stress of the composite hydrogel still reached 84.1% of the first compressive stress. After 24 h of culture, the mortality rate of Staphylococcus aureus treated with simple hydrogel was significantly higher than that treated with PBS (P<0.05); the mortality rates of Escherichia coli and Staphylococcus aureus treated with composite hydrogel alone were significantly higher than those treated with simple hydrogel (P<0.05); the mortality rates of Escherichia coli and Staphylococcus aureus treated with composite hydrogel+light irradiation were significantly higher than those treated with composite hydrogel alone (P<0.05). After 24 h of culture, compared with that cultured in composite hydrogel immersion solution with final mass concentration of 0 mg/mL, the proliferation activity of HFbs cultured in composite hydrogel immersion solution with final mass concentrations of 25.0 and 50.0 mg/mL was significantly enhanced (P<0.05), while the proliferation activity of HFbs cultured in composite hydrogel immersion solution with final mass concentration of 100 mg/mL was significantly decreased (P<0.05). On PID 0 and 3, more purulent secretions were seen in the wounds of mice in blank control group and simple hydrogel group, while only a small amount of exudate was observed in the wounds of mice in composite hydrogel group, and no obvious infection was observed in the wounds of mice in combined treatment group. On PID 7 and 14, the wound healing rates of mice in simple hydrogel group were significantly higher than those in blank control group (P<0.05); the wound healing rates of mice in composite hydrogel group were significantly higher than those in simple hydrogel group (P<0.05); the wound healing rates in combined treatment group were significantly higher than those in composite hydrogel group (P<0.05). On PID 14, the wounds of mice in blank control group exhibited a high infiltration of inflammatory cells with no new epithelial layer observed; the wounds of mice in simple hydrogel group displayed a short length of newly formed epithelium with a small amount of inflammatory cells; the wounds of mice in composite hydrogel group exhibited continuous formation of new epithelium and a large amount of immature granulation tissue; the wounds of mice in combined treatment group showed continuous epithelialization with less immature granulation tissue. Conclusions: The prepared composite hydrogel exhibits excellent thermosensitivity, photothermal properties, and injectability, as well as excellent mechanical properties, antibacterial properties, and biocompatibility, and can promote the healing of infected full-thickness skin defect wounds in mice.

[HIV infection status in male outpatients in sexually transmitted disease clinics in Tianjin, 2016-2020]

Objective: To understand the HIV infection status in male outpatients in sexually transmitted disease (STD) clinics in Tianjin from 2016 to 2020. Methods: According to the sentinel surveillance protocol, continuous cross-sectional studies were conducted between April and June during 2016-2020 to collect the information about the awareness of AIDS related knowledge, related sex behaviors, HIV infection, syphilis prevalence and HCV infection of male STD outpatients in Tianjin with a sample seize of 400 in each sentinel clinic. Results: From 2016 to 2020, a total of 4 000 male STD outpatients were surveyed. The HIV positive rate increased from 1.13% (9/800) to 2.25% (18/800) (trend χ²=14.22, P<0.001), the positive rate of syphilis increased from 9.38% (75/800) to 13.00% (104/800) (trend χ²=7.30, P=0.007) in this population during this period. The overall HCV positive rate was 0.45% (18/4 000). Multivariate logistic regression analysis showed that compared with those who were unmarried, had registered residence in Tianjin, had no temporary sexual behavior in the past 3 months, had no anal sex and had negative syphilis test result, the risk factors of HIV infection in the male STD outpatients included cohabitation (aOR=7.53, 95%CI:2.13-26.62), being from other provinces (aOR=3.64,95%CI:1.58-8.38), having temporary sexual behavior in the past 3 months (aOR=2.24,95%CI:1.03-4.89), having homosexual anal sex (aOR=85.99,95%CI:38.76-190.74) and suffering from syphilis (aOR=6.06,95%CI:3.18-11.56). Conclusion: The detection rates of HIV infection and syphilis in male STD outpatients in Tianjin showed upward trends from 2016 to 2020. Having temporary sexual behavior and anal sex, and suffering from syphilis were the main risk factors of HIV infection in male STD outpatients.

Modeling observations of solar coronal mass ejections with heliospheric imagers verified with the Heliophysics System Observatory

We present an advance toward accurately predicting the arrivals of coronal mass ejections (CMEs) at the terrestrial planets, including Earth. For the first time, we are able to assess a CME prediction model using data over two thirds of a solar cycle of observations with the Heliophysics System Observatory. We validate modeling results of 1337 CMEs observed with the Solar Terrestrial Relations Observatory (STEREO) heliospheric imagers (HI) (science data) from 8 years of observations by five in situ observing spacecraft. We use the self-similar expansion model for CME fronts assuming 60° longitudinal width, constant speed, and constant propagation direction. With these assumptions we find that 23%-35% of all CMEs that were predicted to hit a certain spacecraft lead to clear in situ signatures, so that for one correct prediction, two to three false alarms would have been issued. In addition, we find that the prediction accuracy does not degrade with the HI longitudinal separation from Earth. Predicted arrival times are on average within 2.6 ± 16.6 h difference of the in situ arrival time, similar to analytical and numerical modeling, and a true skill statistic of 0.21. We also discuss various factors that may improve the accuracy of space weather forecasting using wide-angle heliospheric imager observations. These results form a first-order approximated baseline of the prediction accuracy that is possible with HI and other methods used for data by an operational space weather mission at the Sun-Earth L5 point.

Effects of continuous low dose infusion of lipopolysaccharide on inflammatory responses, milk production and milk quality in dairy cows

The objective of this study was to evaluate the effects of continuous low dose infusion of lipopolysaccharide (LPS) on inflammatory responses and milk production and quality in lactating dairy cows. Eight Holstein cows were assigned to two treatments in a cross-over experimental design. Cows were infused intravenously either with saline solution or with saline solution containing LPS from Escherichia coli O111:B4 at a dose of 0.01 μg LPS/kg body weight for approximately 6 hr each day during a seven-day trial. The clinical symptoms and milk production performance were observed. Milk samples were analysed for conventional components, fatty acids and amino acids. And jugular vein and mammary vein plasma samples were analysed for concentrations of cytokines and acute phase proteins. LPS infusion decreased feed intake and milk yield. An increase in body temperature was observed after LPS infusion. LPS infusion also increased plasma concentrations of interleukin-1β, serum amyloid A, LPS-binding protein, C-reactive protein and haptoglobin. LPS infusion decreased the contents of some fatty acids, such as C17:1, C18:0, C18:1n9 (trans) and C18:2n6 (trans), and most amino acids except for methionine, threonine, histidine, cysteine, tyrosine and proline in the milk. The results indicated that a continued low dose infusion of LPS can induce an inflammatory response, decrease milk production and reduce milk quality.

[Different meanings of Long(stranguria) in medicaland historical books in Han Dynasty]

The word "long (stranguria)" is seen both in historical and medical works in the Han Dynasty, but with much different meanings. In medical books, including Nei jing(Inner Canon), Wu shi er bing fang(Prescriptions for Fifty-two Diseases), and Wu wei yi jian(Medical Bamboo slips of Wuwei), Long refers to incontinence of urination. However, in historical books, Long is usually expressed as "pi long" , referring to different conditions, including lame, fatigue, and disability, all congenital or acquired renal deficient illness. It is also seen in unearthed documents as fei ji (disability) and "du long" , referring to congenital or postnatal severe diseases resulting in disability to do anything. Together with orphan, widow, widower, senility, and poverty without relatives for existence, all weak communities need to be supported and saved.

Expression of MMP-1, -2, and -8 in longissimus dorsi muscle and their relationship with meat quality traits in cattle

The extracellular matrix (ECM) is the major macromolecule in skeletal muscle, which affects meat quality greatly. The remodeling of the ECM is mainly regulated by matrix metalloproteinases (MMPs). The expression patterns of MMP-1, -2, and -8 in longissimus dorsi muscle were explored using quantitative real-time polymerase chain reaction. The results show that the expression of MMP-1, -2, and -8 decreased significantly from 135 days of pregnancy to postnatal 30 months. While the expression of MMP-1, -2, and -8 showed no significant relationships with intramuscular fat contents, MMP-1 and -2 showed significant negative correlations with the shearing force of the longissimus dorsi muscle in cattle. The expression of MMP-1 also showed a significant negative correlation with cooking loss and a positive correlation with water holding capacity. The expression levels of MMP-1 and -2 were usually higher in fat than in skeletal muscle tissue. The expression of MMP-8 was significantly higher in the mammary fat pad and the longissimus dorsi muscle than in all other tissues. This study indicates that the remodeling of the ECM has important effects both on the development of postnatal skeletal muscle and on meat quality.

Prediction of G-protein-coupled receptor classes in low homology using Chou's pseudo amino acid composition with approximate entropy and hydrophobicity patterns

We use approximate entropy and hydrophobicity patterns to predict G-protein-coupled receptors. Adaboost classifier is adopted as the prediction engine. A low homology dataset is used to validate the proposed method. Compared with the results reported, the successful rate is encouraging. The source code is written by Matlab.

Hemoglobin H disease in Guangxi province, Southern China: clinical review of 357 patients

The clinical characteristics of 357 patients with hemoglobin H (HbH) disease from the Guangxi province of Southern China were studied. One hundred and ninety-one (53.3%) patients were diagnosed with HbH-Constant Spring, 19 were diagnosed with HbH Westmead. Ten patients were shown to have coinherited HbH-Constant Spring/QS with a β-thalassemia mutation. Coinheritance of the β-thalassemia gene does not alleviate anemia (8.2 ± 2.3 vs. 7.6 ± 1.7 g/dl, p = 0.276), or influence age at diagnosis (20.2 ± 19.6 vs. 12.9 ± 11.0 years, p = 0.276). Ferritin levels were significantly higher in the group of patients with the nondeletional form of the disease (475 ± 719 vs. 249 ± 264 ng/ml, p = 0.005).

[Epidemiological investigation and genotype of thalassemia on middle school students in Chongzuo, Guangxi]

OBJECTIVE

To investigate the carrier ratio and the genotype of thalassemia among students of secondary school in Chongzuo, Guangxi.

METHODS

From June 10-20, 2008 among 7 regions of Chongzuo, 1 secondary school was randomly chosen from each region, and the number of student volunteers was determined by 0.5 per thousand proportion of the local population size. 1097 students were screened, including 515 boys and 582 girls of 12-16 year olds. Among them, 968 cases were Zhuang (438 boys and 530 girls) 128 cases were Han (76 boys and 52 girls) and one case was Yao nationalities (boy). Analysis of blood cells was detected by Cell Dyn 1700 automatic hemocyte analysator while hemoglobin F (HbF) and hemoglobin A2 (HbA2) were detected by hemoglobin autoanalyse variant. Among those with HbA > or = 4% that belonged to beta-thalassemia before alpha and beta-thalassemia gene were analyzed to identify the genotypes. If HbA2 was <4% but MCV< or = 80 fl, alpha-thalassemia gene was analyzed.

RESULTS

Among 1097 cases, 218 were alpha-thalassemia (19.87%), 50 were beta-thalassemia (4.56%) and 13 were combination of alpha beta-thalassemia (1.19%). The overall detected ratio was 25.62%. 133 cases with thalassemia were boys (25.83%) and 148 were girls (25.43%) with no significant difference (P>0.05). 255 cases of thalassemia were Zhuang (26.34%), and 25 were Han nationality (19.52%). The detected ratio among Zhuang nationality was higher than in Han nationality and with significant difference statistically (P<0.01). 3 kinds of deletion (-alpha(3.7)/, -alpha(4.2)/, --(SEA)/) and another 3 kinds of non-deletion (alpha alpha(CS)/, alpha alpha(WS)/, alpha alpha(QS/) alpha-thalassemia genotype were identified, with a higher rate of alpha alpha(WS)/. Among the beta-thalassemia genotype, CD41-42 appeared the most common genotype. MCV of thalassemia was lower than in the controls, with significant difference (P<0.01). 78-90 fl of alpha-thalassemia was detected from the MCV specimen. If taken MCV<79 fl as the positive phenotype of thalassemia, 32 cases were misdiagnosed. The rate of missed diagnosed cases was 2.97%.

CONCLUSION

Rate of thalassemia carrier among students of secondary school in Chongzuo, Guangxi was considered to be high, especially those belonged to Zhuang nationality were higher than the Hans. The carrier rate of alpha alpha(WS)/ was higher, with CD41-42 the most common genotype.

Arsenite, arsenate and vanadate affect human erythrocyte membrane

Effects of arsenite, arsenate and vanadate on human erythrocyte membrane have been assessed according to their routes passing through the membrane, their binding modes to the membrane and their influences on membrane proteins and lipids. The uptake of arsenate (1.0 mM) by cells approached a limit with intracellular arsenic of about 0.2 mM in 5 h, and was strongly inhibited (approximately 95%) by 4,4'-diisothiocyano-2,2'-disulfonic stilbene (DIDS), indicating that arsenate, similar to vanadate, passed across the membrane through the anion exchange protein, band 3. Arsenite (1.0 mM) influx reached a maximum of about 0.4 mM in 30 min, and was not inhibited by DIDS. The transformed species of arsenite bound to the membrane from cytosol. In contrast, arsenate bound rapidly from the outside, followed by releasing and re-binding. The binding to the membrane via sulfhydryl was indicated by the decrease of the sulfhydryl level of membrane proteins. Polyacrylamide gel electrophoresis in sodium dodecyl sulfate (SDS-PAGE) analysis revealed that the proteins, bands 1-3, were among the targets of arsenite, arsenate and vanadate. Their binding to the membrane also induced changes in the fluidity of membrane lipids and in the negative charge density in the outer surface of the membrane.

Fourier-transform ion cyclotron resonance mass spectrometric evidence for the formation of alpha-chloroenethiolates and thioketenes from chloroalkene-derived, cytotoxic 4-thiaalkanoates

The cytotoxicity of chloroalkene-derived cysteine S-conjugates is thought to be associated with the formation of alpha-chloroenethiolates and thioketenes as reactive intermediates. Recent studies indicate that the formation of 1,2-dichloroethenethiolate, which may give rise to chlorothioketene, is a key step in the bioactivation of 5,6-dichloro-4-thia-5-hexenoic acid (Fitzsimmons et al. (1995) Biochemistry 34, 4276-4286). We report here the use of Fourier-transform ion cyclotron resonance mass spectrometry to provide the first direct evidence for the formation of alpha-chloroenethiolate and thioketene species from a cytotoxic 4-thiaalkanoate. The bioactivation of 5,6-dichloro-4-thia-5-hexenoic acid involves conversion to the corresponding CoA thioester 5,6-dichloro-4-thia-5-hexenoyl-CoA and subsequent processing by the fatty acid beta-oxidation pathway. It has been proposed that the bioactivation of 5,6-dichloro-4-thia-5-hexenoyl-CoA involves loss of 1,2-dichloroethenethiolate, followed by loss of chloride to form chlorothioketene. 1,2-Dichloroethenethiolate and related alpha-chloroalkenethiolates have not been observed directly in aqueous solution. Fourier-transform ion cyclotron resonance mass spectrometric experiments show that S-propyl 5,6-dichloro-4-thia-5-hexenethioate reacts in the gas phase with base (hydroxide ion) to release 1,2-dichloroethenethiolate, which is observed directly in the mass spectrum of the products of the gas-phase reaction. Furthermore, the elimination of chloride from 1,2-dichloroethenethiolate on collision-induced decomposition is facile and provides evidence for chlorothioketene formation. Preliminary evidence for the formation of 1,2-dichloroethenethiolate and chlorothioketene from S-(1,2-dichlorovinyl)-N-acetyl-L-cysteine methyl ester was also obtained. These observations support the intermediacy of alpha-chloroenethiolates and chlorothioketenes in the bioactivation of cytotoxic, chloroalkene-derived 4-thiaalkanoates and cysteine S-conjugates and demonstrate the utility of Fourier-transform ion cyclotron mass spectrometry in studying the formation of reactive intermediates.

An innovated treatment for intra-articular fracture of calcaneus

An innovated composite treatment for intra-articular fracture of the calcaneus has been developed. A Steinmann's pin is introduced into the calcaneus percutaneously to release the impaction of the fragments and to lift the compressed subtalar joint facet, which forms a potential cavity in the calcaneal body facilitating restoration of Bohler's angle and correction of widening of the calcaneus by manual reduction. A new type external fixation device, the calcaneus fixation boot, is used to substitute for the traditional plaster immobilization. The boot can exert continuous centripetal pressure on both sides of the calcaneus to control transverse displacement and to maintain the normal height of the heel. The patient is allowed to do functional exercises 24 hours after reduction with the aid of the spring stepping roller, which not only helps dissipate swelling in the early stage but also remold the articular facet. Biomechanical determination showed that the power of triceps surae muscles returned to nearly normal in 4-5 weeks. The patients were allowed to bear weight with crutches in 6-7 weeks. In this series, 94 (87.8%) of 107 cases with an average follow-up period of 2 years and 9 months attained excellent and good results.

[CT diagnosis of myasthenia gravis]

This paper reported 21 cases of myasthenia gravis. All investigated by laboratory tests, conventional chest X-ray study and CT scan, and documented by surgery and pathology. There were 9 cases of thymoma, 2 thymic cyst, 8 normal thymus, 1 atrophic thymus and 1 thymic hyperplasia. In this series, the diagnostic accuracy rate of CT scan was over 90%. Of course, CT is a highly efficient technique for evaluation of abnormalities of thymus, but high resolution CT scanner and the ability of correct interpretation of CT image are even more important.

Effect of glucagon on the motility of esophageal smooth muscle

The functions of glucagon were studied experimentally and clinically. It was found that glucagon (2 x 10(-6)g/ml) could not induce any demonstrable changes in the longitudinal contraction and tonicity of the isolated muscle of the lower esophageal body in 4 rats, nor could cause (0.2 mg iv) significant changes in swallow motility of the esophagus and lower esophageal sphincter (LES) (the esophageal barium transit time, the largest esophageal caliber, the angle of esophageal contraction, the largest LES caliber, and the amount of barium retention at LES) in 6 volunteers under serial-radiography but it (0.2 mg iv) could cause hypomotility of the stomach and duodenum in 19 volunteers. No obvious side-effects were found in 20 volunteers. The recent experimental evidences have suggested that the inhibitory effect of glucagon on the motility of the smooth muscle of the alimentary tract may not be due to its direct action on the receptor, but to its interference with intramural cholinergic neuronal transmission.