[Effect of dexmedetomidine on the intraoperative and early postoperative complications of patients undergoing orthotopic liver transplantation]

Objective: To investigate the effect of dexmedetomidine on the intraoperative and early postoperative complications of patients undergoing orthotopic liver transplantation. Methods: This is a retrospective cohort study. The clinical data of 399 patients who underwent orthotopic liver transplantation at the First Affiliated Hospital of Nanjing Medical University from January 2016 to September 2020 were retrospectively collected. There were 319 males and 80 females, aged (50.9±10.2) years (range: 10 to 73 years). These patients were divided into the control group (369 cases) and the dexmedetomidine group (30 cases) according to whether dexmedetomidine was continuously pumped intravenously during the operation until the operation ended. The 1∶2 propensity score matching was used to match the preoperative and intraoperative conditions of the two groups of patients, and the caliper width was 0.2. Outcome indicators included intraoperative postreperfusion syndrome, acute kidney injury and pulmonary complications within 7 days after surgery, length of hospital stay, time of stay in ICU, duration of assisted mechanical ventilation, rate of reintubation, 6-month and 1-year survival and recurrence-free survival rate after surgery. The independent sample t test, χ2 test, Mann-Whitney U test or Fisher exact test was used to statistically analyze the data of the two groups of patients, respectively. Survival curves of overall survival and disease-free-survival were plotted by Kaplan-Meier method, and the survival rate and recurrence-free survival rate were compared by Log-rank test. Results: A total of 78 patients were included after propensity score matching, including 26 in the dexmedetomidine group and 52 in the control group. The incidence of acute kidney injury in the dexmedetomidine group within 7 days after surgery was 0 (0/26), significantly lower than that of the control group (21.2%,11/52)(corrected χ2=4.776, P=0.029). There were no significant differences in the incidence of intraoperative postreperfusion syndrome and pulmonary complications within 7 days after surgery, length of hospital stay, ICU time, the duration of assisted mechanical ventilation, rate of reintubation, 6-month and 1-year survival, and recurrence-free survival rate after surgery between the two groups (all P>0.05). Conclusion: Continuous infusion of dexmedetomidine via intravenous pump during operation may be beneficial in reducing the incidence of acute kidney injury within 7 days after orthotopic liver transplantation.

[Response of Soil Fungal Community to Biochar Application Under Different Irrigation Water Salinity]

Saline water irrigation can alleviate the shortage of freshwater resources in the northwest arid zone, but long-term saline water irrigation can damage the soil fungal community structure. To alleviate the harm caused by salinity, biochar is used as a soil amendment to improve the soil fungal community structure. To investigate the intrinsic link between biochar application and the structural diversity of fungal communities in saline soils, two irrigation water salinity levels were set:0.35 dS·m-1 (fresh water) and 8.04 dS·m-1 (saline water). At each irrigation water salinity, two levels of biochar application were set:0 t·hm-2 (no application) and 3.7 t·hm-2 (application). High-throughput sequencing results showed that compared to that under fresh water irrigation, saline water irrigation increased fungal community species diversity and decreased fungal community species richness; biochar application under saline water irrigation reduced soil fungal community species diversity and species richness. The dominant fungal phyla in the soils of each treatment were Ascomycota, Mortierellomycota, Basidiomycota, Chytridiomycota, Glomeromycota, Rozellomycota, and Cysticercales, and the dominant genera were Gibberella, Chaetomium, Sarocladium, Stachybotrys, and Fusarium. Compared to that under freshwater irrigation, saline water irrigation significantly increased the relative abundance of Basidiomycota and Chytridiomycota and significantly decreased the relative abundance of Ascomycota and Rozellomycota. The application of biochar under saline irrigation significantly increased the relative abundance of Ascomycota and Sarocladium but significantly decreased the relative abundance of Basidiomycota, Chaetomium, and Fusarium. LEfSe analysis showed that under the condition of no biochar application, saline irrigation reduced the number of potential biomarkers of fungal communities, whereas the application of biochar under the condition of saline irrigation increased the number of potential biomarkers of fungal communities. These results indicated that the application of biochar can improve the saline soil environment and fungal community structure and provide a theoretical basis for reasonable brackish water irrigation and soil fertilization in arid areas.

[Cloning and functional analysis of flavanone synthase Ⅱ from Dendrobium huoshanense]

Flavonoid C-glycosides are a class of natural products that are widely involved in plant defense responses and have diverse pharmacological activities. They are also important active ingredients of Dendrobium huoshanense. Flavanone synthase Ⅱ has been proven to be a key enzyme in the synthesis pathway of flavonoid C-glycosides in plants, and their catalytic product 2-hydroxyflavanone is the precursor compound for the synthesis of various reported flavonoid C-glycosides. In this study, based on the reported amino acid sequence of flavanone synthase Ⅱ, a flavanone synthase Ⅱ gene(DhuFNSⅡ) was screened and verified from the constructed D. huoshanense genome localization database. Functional validation of the enzyme showed that it could in vitro catalyze naringenin and pinocembrin to produce apigenin and chrysin, respectively. The open reading frame(ORF) of DhuFNSⅡ was 1 644 bp in length, encoding 547 amino acids. Subcellular localization showed that the protein was localized on the endoplasmic reticulum. RT-qPCR results showed that DhuFNSⅡ had the highest expression in stems, followed by leaves and roots. The expression levels of DhuFNSⅡ and other target genes in various tissues of D. huoshanense were significantly up-regulated after four kinds of abiotic stresses commonly encountered in the growth process, but the extent of up-regulation varied among treatment groups, with drought and cold stress having more significant effects on gene expression levels. Through the identification and functional analysis of DhuFNSⅡ, this study is expected to contribute to the elucidation of the molecular mechanism of the formation of quality metabolites of D. huoshanense, flavonoid C-glycosides, and provide a reference for its quality formation and scientific cultivation.

[Efficacy observation and compliance analysis of pollen allergen drops in seasonal allergic rhinitis]

To study the efficacy and compliance analysis of pollen allergen drops in the treatment of allergic rhinitis. The method of single-center controlled was used to analyze the dates' results. From July 2021 to September 2021, 80 patients with seasonal allergic rhinitis were referred to the clinic of otorhinolaryngology in First Hospital of Shanxi Medical University.40 patients received sublingual immunotherapy (SLIT group), and the other 40 patients received symptomatic drug treatment as the control group. The total rhinoconjunctivitis symptom score (TRSS), the visual analogue scale(VAS), total medication score (TMS) and combined scores of medication and rhinoconjunctivitis symptoms (CSMRS) of the patient before the start of the treatment and after the first year of the treatment were compared to assess the efficacy of sublingual immunotherapy of Artemisia pollen. Follow the shedding during the study, the safety of the drug and the causes for compliance analysis were analyzed and recorded. The results of comparison with TRSS, VAS, TMS and CSMRS in two groups in the period of pretherapy were as follows: TRSS(12.393±3.023, 12.450±3.029, t=-0.077, P=0.939), VAS(8.357±1.026, 8.400±0.982, t=-0.173, P=0.862), TMS(3.214±0.568, 3.175±0.501, t=0.301, P=0.764), CSMRS (5.286±0.680, 5.253±0.677, t=0.199, P=0.843), there was no significant difference (P>0.05); lower observed symptom scores were got in the post-treatment pollen peak SLIT group compared to the control group, TRSS(3.964±1.551, 7.750±2.169, t=-7.918, P<0.05), VAS(2.893±0.956, 5.175±1.481, t=-8.286, P<0.05), TMS (1.821±0.863, 3.175±0.501, t=-8.163, P<0.05), CSMRS (2.489±0.921, 4.468±0.601, t=-10.723, P<0.05), and the differences between the groups were statistically significant (P<0.05); the SLIT group significantly reduced all symptom scores at the first peak compared to the starting, TRSS(12.393±3.023, 3.964±1.551, t=20.576, P<0.05), VAS (8.357±1.026, 2.893±0.956, t=30.070, P<0.05), TMS (3.214±0.568, 1.821±0.863, t=7.151, P<0.05), CSMRS(5.286±0.680, 2.489±0.921, t=14.533, P<0.05) and there was statistical difference (P<0.05). No significant adverse reactions occured during medication in the SLIT group. A total of 12 cases were shed in the SLIT group, so the compliance rate was 70%. The four reasons were that patients considered the course was long (4 cases, 33%); the drugs were expensive (3 cases, 25%); patients were busy with their work and life (3 cases, 25%); patients were affected by the outbreak (2 cases, 17%). In summary, Artemisia pollen sublingual drops may improve the symptoms of the patients who got allergic rhinitis caused by Artemisia pollen after the treatment for one year. However, due to the lack of sufficient understanding of immunotherapy or the difficulty in adhering to standardized medication, the compliance with sublingual immunotherapy is still poor, the compliance with sublingual immunotherapy needs to be further improved through patient education.

[Analysis of nasal microbial characteristics in patients with allergic rhinitis and non-allergic rhinitis]

Objective: To investigate the characteristics of nasal flora and the pathogenic role of differential microbiome in patients with allergic rhinitis (AR) and non-allergic rhinitis (nAR). Methods: Thirty-five patients with AR who attended the rhinology outpatient clinic of the Second Hospital of Harbin Medical University from February to July 2022 were selected. A total of 35 nAR patients were selected as the test group, and 20 cases of healthy people with physical examination at the same period were selected as the control group, including 39 males and 51 females, aged 8 to 55 years. 16SrDNA High-throughput sequencing was used to analyze the relative abundance from nasal flora in the three groups of subjects. Alpha diversity index analysis was conducted with R software, and differences between groups were analyzed with LEfSe, Metastats, and t tests. At the same time, the role of microbiome and its relationship with environmental factors were analyzed with R software. Results: There was a significant difference in the bacterial composition of the samples from the three groups, with the relative abundance of Staphylococcus aureus (P=0.032) and Corynebacterium proinquum (P=0.032) within the AR group being significantly higher than that of the nAR group, and that of Lactobacillus murinus, Lactobacillus kunkeei, and Alcaligenes faecalis (P value was 0.016, 0.005, and 0.001, respectively) being significantly lower than that of the nAR group. The relative abundance of Ackermannia muciniphila within the nAR group was higher than that of the control group (P=0.009). Correlation analysis of environmental factors showed a negative correlation between Lactobacillus kunkeei and IgE (P=0.044), and a positive correlation between Lactobacillus murinus and age (P=0.019). AR and nAR random forest prediction models were constructed for the five genera, respectively, and the area under the curve (AUC) of the models of Streptococcus-SP-FF10, Pseudoalteromonas luteoviolacea, Pseudomonas parafulva, Acinetobacter ursingii, and Azotobacter chroococcum in the AR group was 100% (95%CI: 100% to 100%). The AUC for the Pseudomonas parafulva, Azotobacter chroococcum, Closoridium baratii, Turicibacter-SP-H121, and Streptococcus lutetiensis models in the nAR group was 98.4% (95%CI: 94.9% to 100%). Conclusions: The distribution of nasal flora in AR patients, nAR patients and healthy subjects is significantly different, and the changes of bacterial flora abundance are significantly related to the occurrence of AR and nAR. Combined detection of microbiota has the potential to diagnose AR and nAR patients.

[Analysis of differences in health awareness among urban and rural elderly population under the background of aging]

Objective: To explore the status quo, differences and influencing factors of health concern among the elderly in urban and rural areas. Methods: The data of China Health and Retirement Tracking Survey (CHARLS) in 2018 were used to describe the health concerns of the elderly in urban and rural areas by selecting relevant indicators. The differences of health concerns of the elderly in urban and rural areas were compared from two aspects of social demographic characteristics and health status. Multivariate logistic regression model was used to analyze the factors affecting the health concern of the elderly in urban and rural areas. Results: A total of 7 758 urban and rural elderly were included, including 1 913 urban elderly and 5 845 rural elderly. Half (3 899, 50.3%) of the elderly are at the average level of health concern, and there is a difference between urban and rural elderly (χ2=186.61,P<0.05). The rural and urban elderly with different characteristics had different health concerns. The rural elderly with more than two diseases had higher health concerns (χ2=13.71, P=0.001), and different living types of urban elderly people have different health concerns (χ2=28.96, P<0.001). Regression analysis showed that the health concern of the elderly in urban and rural areas was affected by many factors, gender (OR=1.51, P<0.001), health status (OR=2.18, P<0.001), cognitive function impairment (OR=2.93, P<0.001), depression (OR=0.49, P<0.001) is the main factor affecting the difference of health attention of the elderly in urban and rural areas. Whether to receive pension was the influential factor of health concern of the rural elderly (OR=0.63, P<0.05); Disability was an influential factor in the health concern of the urban elderly (OR=2.11, P<0.05). Conclusion: There is much room to improve the health attention of the elderly in urban and rural areas. It is suggested to increase the economic security of the elderly in rural areas and pay special attention to the disabled elderly in urban areas, so as to further improve the health status of the elderly groups.

[Application and prospect of artificial intelligence in pancreatic cancer]

As a severe malignant tumor of the digestive system,the highly invasive pancreatic cancer lacks typical preliminary symptoms. Rapid metastatic dissemination and difficulty in early-stage diagnosis preclude the chance of radical curative resection,hence resulting in a poor overall prognosis in most patients. In recent years,the wide application of the artificial intelligence(AI),represented by machine learning and deep learning,has developed rapidly in the field of medicine. All sorts of models based on AI have been applied to the screening, early diagnosis, treatment, prognosis prediction of patients with pancreatic cancer.Three-dimentional visualization and augmented reality navigation technologies have also been developed and applied in pancreatic cancer surgery.This paper reviews the status quo of AI application in pancreatic cancer from various aspects,and anticipates its future application prospects.

[Endovascular repair of ruptured abdominal aortic aneurysms assisted by double balloon occlusion technique combined with intra-aneurysm fibrin binder injection technique]

Objective: To investigate the long-term efficacy and safety of alternating double balloon occlusion combined with intra-aneurysm injection of human fibrin binder in the endovascular repair of ruptured abdominal aortic aneurysm (rAAA). Methods: The clinical data of 28 patients with rAAA admitted to Department of Vascular Surgery, the Fourth Affiliated Hospital of Guangxi Medical University from January 2015 to December 2019 were retrospectively analyzed. There were 23 males and 5 females, aged (62±5) years (range: 46 to 88 years).The maximum diameter of the tumors was (65.2±10.5) mm (range: 47.3 to 100.5 mm), all of which were subrenal rAAA. The intraoperative EVAR for abdominal aortic aneurysm was successfully performed under the emergency green channel procedure, and this surgery was assisted used the double balloon occlusion technique in aorta of inferior renal and superior renalcombined with intraoperative human fibrin binder injection technique. Observation indexes included: patients with preoperative preparation, operation time, hospitalization days, surgical treatment success rate and the incidence of postoperative complications, and aortic stent form during the follow-up period, the incidence of leakage, branch stents patency rate and infection rates. Results: The preoperative preparation time of 28 patients was (45.5±8.5) minutes (range:20 to 100 minutes). The operation time was (100.0±15.5) minutes (range:85 to 210 minutes), the ICU stay time was (7±2) days(range:1 to 17 days). The length of hospitalization was (13.5±2.5) days(range:5 to 43 days). The success rate of surgical treatment was 92.9% (26/28). Two patients died, 1 case died of postoperative multifocal lacunar cerebral infarction and massive gastrointestinal hemorrhage, and another elderly patient (84 years old) died of massive abdominal fluid due to preoperative abdominal aortic aneurysm rupture, postoperative complicated with significant abdominal compartment syndrome, and secondary multiple organ failure. Balloon occlusion of the upper renal aorta took (13±2)minutes (range:12 to 30 minutes). The intraoperative injection of fibrin adhesive was (14±2) ml(range:6 to 28 ml) in 22 cases. The incidence of major postoperative complications was 57.1% (16/28). Among the 26 patients who survived the surgery, 69.2% (18/26) completed the 3-year follow-up, and the follow-up time was (30±3) months(range:13 to 36 months). During the follow-up, the aortic stent was in good shape without obvious displacement. The incidence of leakage within 6 months after the operation was 10.7% (3/28), and there was no internal leakage in the patients who were followed up for 36 months after the operation. The patency rate of renal artery and iliac artery branch stents was 16/18. The incidence of stent infection was 7.7% (2/26), 1 case occurred at 1 month and another case at 6 months, respectively. All patients recovered after prolonged intensive anti-infection therapy. Conclusions: Under the standard emergency treatment process, the double balloon alternating occlusion technique combined with the intra-aneurysm injection of human fibrin adhesive technique can assist the successful completion of the endovascular repair of rAAA, effectively improve the success rate of treatment for patients, and reduce the incidence of postoperative leakage and serious complications. The mid-term and long-term results of EVAR for rAAA are good, safe and reliable.

[Clinical characteristics of LC-BPPV patients with bilateral direction-fixed horizontal nystagmus in primary Roll test]

Objective:To investigate the clinical features of LC-BPPV with direction-fixed horizontal nystagmus in the primary Roll test. Method:Nine patients of LC-BPPV with bilateral direction-fixed horizontal nystagmus in the first Roll test were treated by repositioning maneuvers after judging the affected side and the prognosis was observed. Result:The affected side of eight patients was the side of the apogeotropic nystagmus. Barbecue or Gufoni maneuvers was effective for reposition. The other one had no conversion of nystagmus and could not judge the affected side. Conclusion:The nystagmus performance of patients with LC-BPPV is complicated. It is necessary to carefully analyze the nystagmus performance of each position. Combining with bow and lean test, lying down test and null plane, the position of the otolith is inferred. Comprehensive use of the Barbecue or Gufoni maneuvers, forced side lying on the affected side, mastoid sniper, shaking head method is effective to complete the reposition treatment.

[Application of lower abdominal aorta balloon occlusion technique by ultrasound guiding during caesarean section in patients with pernicious placenta previa]

Objective: To discuss the feasibility, effect and safety of lower abdominal aorta balloon occlusion technique by ultrasound guiding during caesarean section in patients with pernicious placenta previa. Methods: The clinical data of 40 patients with pernicious placenta previa complicated with placenta accreta from January 2015 to August 2017 in Liuzhou workers hospital were analyzed retrospectively. The study group included 20 cases, which were operated in the way of cesarean section combined lower abdominal aorta balloon occlusion technique by ultrasound guiding, while the control group also included 20 cases, which were operated in the way of the conventional cesarean section without balloon occlusion technique. The bleeding amount, blood transfusion volume, operative total time, hysterectomy and complications of the two groups were compared. Results: The bleeding amount and blood transfusion volume in study group were(850±100)ml and (400±50)ml, which were lower than that of the control group[(2 500±230)ml and (1 500±100)ml], the difference was statistically significant(t=35.624, 16.523, all P<0.05). In addition, the hysterectomy rate in study group was 5%, which was lower than that in the control group(30%), the difference was statistically significant(χ²=8.672, P<0.05). And the total time of operation was (2.0±0.5)h in the study group, which was shorter than that in the control group[(3.5±0.4)h]. The difference was statistically significant(t=11.362, P<0.05). No postoperative complications took place in the study group.The blood pressure, heart rate and blood oxygen fluctuated significantly, and the postoperative renal function was significantly reduced in the control group. Conclusions: The lower abdominal aorta balloon occlusion technique by ultrasound guiding during a caesarean section in patients with pernicious placenta previa can effectively control the bleeding during operation, and preserve reproductive function to the utmost degree.Therefore, the technique is safe, feasible, convenient and cheaper, and worthy of being widely applied in clinic.

[Curative effect analysis of the vestibular rehabilitation training on residual dizziness after successful canalith repositioning maneuvers in patients with benign paroxysmal positional vertigo]

Objective:To explore the curative effect and quality life of the vestibular rehabilitation training on residual dizziness after successful canalith repositioning maneuvers in patients with benign paroxysmal positional vertigo (BPPV). Method:Residual dizziness after successful canalith repositioning maneuvers in patients with BPPV were enrolled in our study. They were randomized into three groups, the control group A were no disposition which include 32 patients, the intervention group B were guided to self rehabilitation training which include 33 patients, the control group C were guided to Brandt Daroff training which include 33 patients. Dizziness handicap inventory (DHI) and residual dizziness duration were used to evaluation the patients. Result:After one week vestibular rehabilitation training, the scores of DHI in group B and C decreased, and there was no significant difference (P>0.05), there were significant differences between group B and group C in group A, respectively (P<0.01). After four weeks of vestibular rehabilitation training, the scores of DHI in group B and group C were lower than those in group A, the decrease of group B was significantly higher than that of group C (P<0.01). The residual dizziness duration indicated that no statistical differences in the B, C groups (P>0.05) and scores of group B,C were significantly lower than group A (P<0.05). Conclusion:The appropriate vestibular rehabilitation training on residual dizziness after successful canalith repositioning maneuvers in patients with BPPV can help promote the central vestibular compensation, reduce the residual symptoms, improve the quality life of patients, and which can be used as the adjuvant treatment on BPPV patient who has residual dizziness symptoms.

[Forensic Pathological Examination on 73 Medical Malpractice Cases of Pediatrics]

OBJECTIVES

To analyse 73 medical malpractice cases of pediatrics for discussing the importance of forensic pathology in solving the issues such as medical malpractice of pediatrics.

METHODS

From January 2002 to August 2016, 73 medical malpractice cases of pediatrics with age of death between 28 days old and 10 years old were collected from Institute of Judical Expertise of Nanjing Medical University. The relationship between causes of death and related medical institutions was retrospectively analysed.

RESULTS

In 73 cases, the male to female ratio was 1.70∶1, and ages of 28 days old to 1 year old were common （26 cases, 35.62%）, followed by ages between 1 year old and 3 years old （21 cases, 28.77%）. In 71 cases which had been determined the cause of death by postmortem examination, the main cause of death was disease, especially respiratory diseases （33 cases, 46.48%）, followed by cardiovascular diseases （12 cases, 16.90%）. In 75 medical institutes which involved with these medical malpractices, most were tertiary medical institutes （32, 42.67%）, followed by the sub-secondary （excluding the secondary） medical institutions （23, 30.67%）. The clinical diagnosis of 38 cases （52.05%） completely or mostly corresponded with the pathological findings. There were 35 cases （47.95%） undefined or misdiagnosed cases.

CONCLUSIONS

Autopsy and forensic pathological examination contribute to determine causes of death, which not only provide scientific evidence for medical malpractice of pediatrics, but also enrich and develop clinical medical knowledge, and thus improve diagnosis and treatment level in a certain extent.

[Langerhans cell sarcoma: a clinicopathologic analysis of four cases]

Objective: To investigate the clinicopathological features, differential diagnosis, and genetic alteration of Langerhans cell sarcoma (LCS). Methods: Four cases of LCS were collected from Fujian Provincial Hospital and Fuzhou General Hospital of Nanjing Military Command of PLA from July 2013 to January 2017. Clinicopathological features and immunophenotype were retrospectively reviewed in four LCS cases combined with genetic mutation analysis of BRAF and ALK. Results: Four cases included 2 women and 2 men with ages from 42 to 79 years (median=59.3 years). The size of the tumors ranged from 2.5-7.8 cm. Histologically, at the low power field, the tumors consisted of highly cellular proliferation in fascicules, whirlpool and diffuse sheets arrangement. The tumor cells were kidney-or horseshoe-shaped to round epithelioid cells or enlarged spindle cells. The neoplastic cells showed cytological atypia, hyperchromatic nuclei with prominent 1 to 2 nucleoli. Multinucleated giant cells were also found. Mitotic activity was approximately (50-70) mitoses/10 HPF. Immunohistochemically, the tumor cells were positive for S-100 protein (4/4), SOX10(3/4), Langerin/CD207(4/4), CD1a(3/4), CD68(3/4), CD163(3/4), and INI-1(4/4). Ki-67 index was 30%-80%. Gene mutation analysis showed that one case had BRAF V600E mutation but none had ALK gene alteration. Conclusions: LCS is a rare tumor with highly malignant potential and distinct morphologic features.The primary treatment for LCS is completely surgical excision and chemotherapy. The prognosis is generally poor.

Parathyroid hormone (1-34) promotes fracture healing in ovariectomized rats with type 2 diabetes mellitus

Ovariectomized (OVX) rats with type 2 diabetes mellitus (T2DM) with femur fracture received vehicle, insulin, or insulin plus parathyroid hormone (PTH) treatment for 2 and 3 weeks. Radiography, histomorphometry, histology, and immunohistochemistry in callus were evaluated.

INTRODUCTION

Reports about effects of PTH plus insulin on callus formation of osteoporotic fracture with T2DM were limited. This study was designed to investigate the effects of the combination of PTH and insulin on fracture healing in OVX rats with T2DM.

METHODS

Two-month-old female rats were randomly divided into five groups: normal fracture (F), OVX fracture (OF), T2DM + OVX fracture (DOF), insulin-treated (2-4 u/daylight, 4-6 u/night, DOFI), and treated with insulin and PTH (50 μg/kg/day, 5 days/week, DOFIP). A closed mid-shaft fracture was established in the right femurs of all rats after 6 weeks of OVX. Rats were euthanized at 2 and 3 weeks post-fracture according to the time schedule, respectively.

RESULTS

The administration of insulin alone or insulin combined with PTH significantly increased mineralized bone volume fraction (BV/TV) and connectivity density (Conn.D) compared with those of the DOF group at 3 weeks post-fracture and also increased cartilaginous callus area ratio in the DOFI and DOFIP groups at 2 weeks and bony callus area ratio in the DOFIP groups at both the 2 and 3 weeks post-fracture.

CONCLUSIONS

OVX rats with T2DM exhibited a marked delay in the fracture healing process; insulin treatment ameliorated these effects, and the healing process was enhanced following treatment with a combination of insulin and PTH.

[Expression of C3d in normal human liver tissues with non-immunologic osmostic mechanism]

Objective: To observe the deposition of complement C3d at different development stages in human normal organs and tissues, and investigate the significance of its deposition. Methods: Using immunohistochemical methods, the deposition of C3d was detected at different development stages of 60 normal human organs and tissue specimens and double staining was performed in some specimens. Ninty-five cases of other organs or tissues were collected as control group. Results: In 50 of 60 livers, it was observed the deposition of C3d in Glisson's capsule and periportal sheath, with irregular linear network-like disposition surrounding the portal sheath. In different age groups, the expression of C3d was more beyond the 20 year-old group than 3 to 20 year-old group. There wasn't any expression of C3d under 3-year-old group. Under the immuning electron micrograph, C3d depositing at the Glisson's capsule was observed, without immuning compounding. Thirty in 40 spleens, deposition of C3d in capsules, arteries of lymphatic sheath, follicles in the spleen was observed. Conclusions: The deposition of C3d in Glisson's capsule, splenic trabeculae, fibrous sheath, endarterium of liver and spleen arterioles, within normal human tissues from patients elder than 3 years, are osmosis/immunogenic deposition. The deposition of C3d is a normal physiological phenomenon, and treatment of the deposition of C3d should be avoided, as it is an immune complex or immuning reaction phenomenon.

SYNTHESIS AND CHARACTERIZATION OF POLYSIALIC ACID/CARBOXYMETHYL CHITOSAN HYDROGEL WITH POTENTIAL FOR DRUG DELIVERY

A novel hydrogel was prepared from polysialic acid (PSA) and carboxymethyl chitosan (CMCS) using glutaraldehyde as the cross-linking agent. The resulting PSA-CMCS hydrogel exhibited pH sensitivity, in which the swelling ratio under acidic conditions was higher than those under neutral or alkaline conditions. The swelling ratio of PSA-CMCS hydrogel at equilibrium depended on the medium pH, the cross-linking agent concentration, and the ratio of PSA to CMCS (w/w). Bovine serum albumin (BSA) and 5-fluorouracil (5-FU) were used as model drugs to prepare hydrogel delivery systems. The loading efficiencies of the hydrogel for BSA and 5-FU were 26.25 and 36.74%, respectively. Release behaviors of BSA and 5-FU were influenced by the pH. MTT assays confirmed that PSA-CMCS hydrogel has no cytotoxicity toward the NIH-3T3 cell line; in fact, the 100% aqueous extract of the PSA-CMCS hydrogel enhanced cell growth. These results suggest that PSA-CMCS hydrogel may be a promising pH-sensitive delivery system, especially for hydrophobic chemicals.

An increase of curdlan productivity by integration of carbon/nitrogen sources control and sequencing dual fed-batch fermentors operation

Curdlan is produced by Agrobacterium sp. ATCC 31749 under nitrogen-limited conditions not associated with cell growth. A novel curdlan production process was developed based on the different nutrient requirements for microbial cell growth and its efficiency was increased by integrating carbon/nitrogen sources control and sequencing dual fed-batch fermentors operation. By feeding ammonium solution to supply abundant nitrogen source and controlling pH in Fermentor I, cell growth was accelerated. High cell density of 29 g/L was attained. The culture broth in Fermentor I was then inoculated into sequencing Fermentor II which alleviated the high requirement for dissolved oxygen and accumulation of inhibitory metabolic by-products during curdlan production. Fermentor I promoted cell growth. Curdlan production started instantaneously in Fermentor II. By feeding nutrient solution with high carbon/nitrogen ratio and NaOH solution for pH adjustment, a feasible and optimal curdlan production process was formulated. The productivity, conversion efficiency and curdlan yield were achieved of 0.98 g/(L h), 57% (w) and 67 g/L, respectively. Such novel process can be scaled up for significant cost reduction at the industrial level.

Barriers to tuberculosis care for drug users in two provinces of China: a qualitative study

SETTING

Two compulsory drug rehabilitation centres in Yunnan and Sichuan Provinces, Southwest China.

OBJECTIVE

To understand barriers to tuberculosis (TB) care among drug users in China, and to provide policy recommendations to improve TB control in the drug-using population.

DESIGN

A qualitative study was designed using in-depth interviews with 147 drug users with TB and 12 key informants. Drug users were purposively selected from two compulsory drug rehabilitation centres and key informants from national and provincial justice administration, local TB control dispensaries and compulsory drug rehabilitation centres.

RESULTS

Lack of health awareness and knowledge was reported as one barrier to TB care among drug users. The majority of the respondents lacked social support and perceived fear and stigma when seeking TB care. More than half of the respondents who had discontinued their anti-tuberculosis treatment reported that this was due to drug use. Limited provision of TB care in the compulsory drug rehabilitation centres and local TB control dispensaries was also reported as one of the barriers to TB care among drug users.

CONCLUSIONS

These findings suggest that barriers to TB care for drug users are associated not only with the drug users themselves, but also with the providers and societal factors. Health professionals and policy makers should be aware of these barriers in China.

Effective fast electron acceleration along the target surface

The dependence of angular distributions of fast electrons generated in the interaction of p-polarized femtosecond laser pulses with foil targets on laser intensities is investigated. A novel fast electron beam along the front target surface is observed for high laser intensity. It is found that the electron acceleration along the target surface is more efficient than those in other directions.

Effect of target shape on fast electron emission in femtosecond laser-plasma interactions

Fast electron emission from the interaction of femtosecond laser pulses with shaped solid targets has been studied. It is found that the angular distributions of the forward fast electrons are highly dependent upon the target shapes. The important roles played by the electrostatic fields built up at the non-laser-irradiated target surfaces and the collisions in the target are identified. Our two-dimensional particle-in-cell simulations with binary collisions included reproduce the main experimental observations.

Oval-like hollow intensity distribution of tightly focused femtosecond laser pulses in air

The propagation of a tightly focused femtosecond laser pulse in air has been investigated. Unlike long-distance self-guided propagation of short laser pulses, a novel oval-like hollow distribution of the laser intensity is observed in the experiments and reproduced by the numerical simulations. The formation of the hollow structures can be explained by the interplay between ionization-induced refraction and Kerr self-focusing.

Observation of a fast electron beam emitted along the surface of a target irradiated by intense femtosecond laser pulses

A novel fast electron beam emitting along the surface of a target irradiated by intense laser pulses is observed. The beam is found to appear only when the plasma density scale length is small. Numerical simulations reveal that the electron beam is formed due to the confinement of the surface quasistatic electromagnetic fields. The results are of interest for potential applications of fast electron beams and deep understanding of the cone-target physics in the fast ignition related experiments.

Energetic electrons emitted from ethanol droplets irradiated by femtosecond laser pulses

We investigate the angular distribution and the energy spectrum of hot electrons emitted from ethanol droplets irradiated by linearly polarized 150-fs laser pulses at an intensity of 10(16) W/cm(2). Two hot electron jets symmetrically with respect to the laser propagation direction are observed within the polarization plane. This is due to the spherical geometry of droplets in the intense laser field. The maximum energy of the hot electrons is found to be more than 600 keV. Particle-in-cell simulations suggest that the resonance absorption is the main mechanism for hot electron generation.

Blast waves produced by interactions of femtosecond laser pulses with water

The behaviors of the blast waves produced by femtosecond laser-water interactions, and the blast waves induced by laser self-focusing in air, have been investigated using optical shadowgraphy at a maximum intensity of 1 x 10(16) W/cm(2). The temporal evolution of the blast wave launched by the water plasma can be described by a planar blast wave model including source mass. An aneurismlike structure, due to the quick propagation inside a hollow channel formed by laser self-focusing, is observed. The expansion of the channel in air is found to agree with a cylindrical self-similar blast wave solution.

Bile acid activation of the gadd153 promoter and of p53-independent apoptosis: relevance to colon cancer

Bile acids are strongly implicated in the etiology of colon cancer. Bile acids also induce apoptosis, and this action may be a key to understanding their role in colon cancer. However the mechanism of bile acid induction of apoptosis is not known. We present evidence of bile acid activation of the gadd153 promoter (a promoter activated by DNA damaging agents). We also show that bile acid induction of apoptosis is p53-independent. In addition, bile salts were found to induce blebbing preceding the actual morphological onset of apoptosis, which indicates early cytoskeletal alterations.

Apparent ineffectiveness of natural killer cells vis-à-vis retrovirus-infected targets

The role of NK cells in the defense against retroviral infections is ill defined. The discovery of the pathogenic human retroviruses and their epidemic spread have made more urgent a better understanding of how such infections may be naturally controlled. Therefore, a systematic study was undertaken to determine whether NK cells obtained from healthy individuals are able to recognize and lyse target cells that have been infected with HTLV-I, HTLV-II, or HIV. The studies demonstrated that NK cells can recognize retrovirus-infected cells as evidenced by rapid conjugation, but that neither freshly isolated, nor IL-2 stimulated cells cause lysis of such targets. As has been reported for NK-resistant tumor cells, removal of sialic acid residues rendered the retrovirus-infected target cells vulnerable to NK cell attack. Although these data do not suggest that boosting natural immunity would be a useful treatment modality for patients with AIDS or HTLV-related diseases, the observations may help to explain why the small number of cells that harbor retroviruses in patients with subclinical infection are not eliminated.

Apparent ineffectiveness of natural killer cells vis-à-vis retrovirus-infected targets

The role of NK cells in the defense against retroviral infections is ill defined. The discovery of the pathogenic human retroviruses and their epidemic spread have made more urgent a better understanding of how such infections may be naturally controlled. Therefore, a systematic study was undertaken to determine whether NK cells obtained from healthy individuals are able to recognize and lyse target cells that have been infected with HTLV-I, HTLV-II, or HIV. The studies demonstrated that NK cells can recognize retrovirus-infected cells as evidenced by rapid conjugation, but that neither freshly isolated, nor IL-2 stimulated cells cause lysis of such targets. As has been reported for NK-resistant tumor cells, removal of sialic acid residues rendered the retrovirus-infected target cells vulnerable to NK cell attack. Although these data do not suggest that boosting natural immunity would be a useful treatment modality for patients with AIDS or HTLV-related diseases, the observations may help to explain why the small number of cells that harbor retroviruses in patients with subclinical infection are not eliminated.

Bile salt/acid induction of DNA damage in bacterial cells: effect of taurine conjugation

Bile salts and acids have been implicated in the etiology of colon cancer, possibly through their ability to cause DNA damage. Taurine-conjugated and nonconjugated forms of three bile salts and one bile acid were tested for DNA repair-inducing potential and for cellular toxicity in a recently developed Escherichia coli chromotest system. The taurine-conjugated forms of sodium deoxycholate and lithocholic acid had reduced ability to induce DNA repair. Also the taurine-conjugated form of lithocholic acid had a reduced lethal effect. These observations suggest that the biotransformation step, whereby bacteria in the intestine remove the taurine added to bile salts in the liver, may be significant in the etiology of colon cancer.

Macrophage membrane glycoproteins that bind Griffonia simplicifolia I-B4: effect on cytotoxicity and protein secretion

Thioglycollate elicited peritoneal (TG-Møs) but not resident peritoneal Møs (R-Møs) were found to bind the lectin Griffonia simplicifolia isotype I-B4 (GSI-B4). This was demonstrated by ultrastructural studies and FACS analyses. Membranes from TG-Møs were isolated, separated on SDS-PAGE, electrotransferred onto nitrocellulose, and exposed to peroxidase-labeled GSI-B4. These procedures revealed two major membrane glycoproteins of molecular weights 180,000 and 94,000 daltons that bound the lectin GSI-B4 which has a specificity for recognizing terminal alpha-galactosyl residues. The presence of these epitopes on the two membrane glycoproteins was further substantiated by the fact that treatment of the membranes with alpha-galactosidase destroyed their capacity to bind GSI-B4 and that alpha-D-galactopyranoside but not N-acetyl-D-glucosamine competitively inhibited GSI-B4 from binding to the glycoproteins. Treatment of TG-Møs with GSI-B4 reduced the capacity of interferon (IFN) and lipopolysaccharide (LPS), or IFN alone, to induce Mø mediated cytotoxicity towards tumor cells by as much as 40%. GSI-B4 also caused alterations in the pattern of biosynthetically 35S-methionine labeled secreted proteins as early as 2 hours after contact with TG-Møs. Out of 35 discernible proteins on fluorograms of SDS-PAGE separated proteins, 5 were down-regulated and 9 were enhanced. It is suggested that the two novel Mø membrane proteins may play a role in regulating the response of Mø subpopulations to their humoral and cellular environments.

Internalization of human immunodeficiency virus type I and other retroviruses by megakaryocytes and platelets

Direct infection of megakaryocytes and platelets by human immunodeficiency virus type I (HIV-I) or other retroviruses has not been demonstrated. To determine whether this could occur, murine bone marrow was co-cultivated with the amphotropic retrovirus-producing cell line PA317-N2, and freshly isolated normal human bone marrow and platelets were co-cultivated with HIV-infected H9 cells. In each case, ultrastructural analyses showed viruses within megakaryocytes and platelets. In murine specimens, the uptake of retrovirus was avid at all stages of differentiation. In human specimens, viral uptake was less frequent. These results suggest that direct infection of megakaryocytes could play a role in the pathophysiology of HIV-associated disease. In addition, these observations suggest that cells of the megakaryocyte lineage could serve as target cells in gene transfer experiments using retroviral-based vectors.

[Influence of 6,7-dimethoxycoumarin on toxicity and pharmacodynamics of cyclophosphamide]

When 40 mg/kg of 6,7-dimethoxycoumarin (DMOC) was given (ip) 15 min before sc cyclophosphamide (Cy), the LD50/7 d of Cy would be raised from 166 +/- 9 (100-245) to 294 +/- 4 (250-346) mg/kg (dose reduction factor 1.78) in Wistar rat. The 7 d survival rate of mice intoxicated by Cy was raised to 26.7%. To give 100 mg/(kg.d) of DMOC for 5 or 24 days, it prevented the chronic toxicity of Cy prolonged the life-span, elevated the 30 d survival rate of rats intoxicated by Cy to 45.3 and 42.5%, respectively. DMOC increased the WBC, weight of thymus and body of rats and mice intoxicated by Cy; raised colony-forming unit and reduced high plasma corticosterone of mice intoxicated by Cy. It also increased the RNA and DNA of bone marrow, liver and spleen. DMOC in combination with Cy did not reduce the antitumor effect of Cy.

An improved technique of radical neck dissection with an analysis of long-term results of 1,000 operated cases of head and neck cancer

An improved technique of radical neck dissection is presented with a report of all 1,000 operated cases of the head and neck region from 1964 to 1980 at the Affiliated Tumor Hospital of Zhongshan Medical College, in Guangzhou, China. The practice has proved that our operative procedures are time-saving, with less blood loss during operation, fewer operative mortalities, fewer complications, better end results, better cosmetic effects, and that the techniques are easier to master.