[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.

[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.

Proteogenomic Approaches for the Identification of NF1/Neurofibromin-depleted Estrogen Receptor-positive Breast Cancers for Targeted Treatment

NF1 is a key tumor suppressor that represses both RAS and estrogen receptor-α (ER) signaling in breast cancer. Blocking both pathways by fulvestrant (F), a selective ER degrader, together with binimetinib (B), a MEK inhibitor, promotes tumor regression in NF1-depleted ER⁺ models. We aimed to establish approaches to determine how NF1 protein levels impact B+F treatment response to improve our ability to identify B+F sensitive tumors. We examined a panel of ER⁺ patient-derived xenograft (PDX) models by DNA and mRNA sequencing and found that more than half of these models carried an NF1 shallow deletion and generally have low mRNA levels. Consistent with RAS and ER activation, RET and MEK levels in NF1-depleted tumors were elevated when profiled by mass spectrometry (MS) after kinase inhibitor bead pulldown. MS showed that NF1 can also directly and selectively bind to palbociclib-conjugated beads, aiding quantification. An IHC assay was also established to measure NF1, but the MS-based approach was more quantitative. Combined IHC and MS analysis defined a threshold of NF1 protein loss in ER⁺ breast PDX, below which tumors regressed upon treatment with B+F. These results suggest that we now have a MS-verified NF1 IHC assay that can be used for patient selection as a complement to somatic genomic analysis.

Significance

A major challenge for targeting the consequence of tumor suppressor disruption is the accurate assessment of protein functional inactivation. NF1 can repress both RAS and ER signaling, and a ComboMATCH trial is underway to treat the patients with binimetinib and fulvestrant. Herein we report a MS-verified NF1 IHC assay that can determine a threshold for NF1 loss to predict treatment response. These approaches may be used to identify and expand the eligible patient population.

[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.

Elevated NRAS expression during DCIS is a potential driver for progression to basal-like properties and local invasiveness

BACKGROUND

Ductal carcinoma in situ (DCIS) is the most common type of in situ premalignant breast cancers. What drives DCIS to invasive breast cancer is unclear. Basal-like invasive breast cancers are aggressive. We have previously shown that NRAS is highly expressed selectively in basal-like subtypes of invasive breast cancers and can promote their growth and progression. In this study, we investigated whether NRAS expression at the DCIS stage can control transition from luminal DCIS to basal-like invasive breast cancers.

METHODS

Wilcoxon rank-sum test was performed to assess expression of NRAS in DCIS compared to invasive breast tumors in patients. NRAS mRNA levels were also determined by fluorescence in situ hybridization in patient tumor microarrays (TMAs) with concurrent normal, DCIS, and invasive breast cancer, and association of NRAS mRNA levels with DCIS and invasive breast cancer was assessed by paired Wilcoxon signed-rank test. Pearson's correlation was calculated between NRAS mRNA levels and basal biomarkers in the TMAs, as well as in patient datasets. RNA-seq data were generated in cell lines, and unsupervised hierarchical clustering was performed after combining with RNA-seq data from a previously published patient cohort.

RESULTS

Invasive breast cancers showed higher NRAS mRNA levels compared to DCIS samples. These NRAShigh lesions were also enriched with basal-like features, such as basal gene expression signatures, lower ER, and higher p53 protein and Ki67 levels. We have shown previously that NRAS drives aggressive features in DCIS-like and basal-like SUM102PT cells. Here, we found that NRAS-silencing induced a shift to a luminal gene expression pattern. Conversely, NRAS overexpression in the luminal DCIS SUM225 cells induced a basal-like gene expression pattern, as well as an epithelial-to-mesenchymal transition signature. Furthermore, these cells formed disorganized mammospheres containing cell masses with an apparent reduction in adhesion.

CONCLUSIONS

These data suggest that elevated NRAS levels in DCIS are not only a marker but can also control the emergence of basal-like features leading to more aggressive tumor activity, thus supporting the therapeutic hypothesis that targeting NRAS and/or downstream pathways may block disease progression for a subset of DCIS patients with high NRAS.

[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.

Neurofibromin Is an Estrogen Receptor-α Transcriptional Co-repressor in Breast Cancer

We report that neurofibromin, a tumor suppressor and Ras-GAP (GTPase-activating protein), is also an estrogen receptor-α (ER) transcriptional co-repressor through leucine/isoleucine-rich motifs that are functionally independent of GAP activity. GAP activity, in turn, does not affect ER binding. Consequently, neurofibromin depletion causes estradiol hypersensitivity and tamoxifen agonism, explaining the poor prognosis associated with neurofibromin loss in endocrine therapy-treated ER⁺ breast cancer. Neurofibromin-deficient ER⁺ breast cancer cells initially retain sensitivity to selective ER degraders (SERDs). However, Ras activation does play a role in acquired SERD resistance, which can be reversed upon MEK inhibitor addition, and SERD/MEK inhibitor combinations induce tumor regression. Thus, neurofibromin is a dual repressor for both Ras and ER signaling, and co-targeting may treat neurofibromin-deficient ER⁺ breast tumors.

[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.

Induction of N-Ras degradation by flunarizine-mediated autophagy

Ras GTPases are powerful drivers for tumorigenesis, but directly targeting Ras for treating cancer remains challenging. The growth and transforming activity of the aggressive basal-like breast cancer (BLBC) are driven by N-Ras. To target N-Ras in BLBC, this study screened existing pharmacologically active compounds for the new ability to induce N-Ras degradation, which led to the identification of flunarizine (FLN), previously approved for treating migraine and epilepsy. The FLN-induced N-Ras degradation was not affected by a 26S-proteasome inhibitor. Rather, it was blocked by autophagy inhibitors. Furthermore, N-Ras can be seen co-localized with active autophagosomes upon FLN treatment, suggesting that FLN alters the autophagy pathway to degrade N-Ras. Importantly, FLN treatment recapitulated the effect of N-RAS silencing in vitro by selectively inhibiting the growth of BLBC cells, but not that of breast cancer cells of other subtypes. In addition, in vivo FLN inhibited tumor growth of a BLBC xenograft model. In conclusion, this proof-of-principle study presents evidence that the autophagy pathway can be coerced by small molecule inhibitors, such as FLN, to degrade Ras as a strategy to treat cancer. FLN has low toxicity and should be further investigated to enrich the toolbox of cancer therapeutics.

[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.

Abstract 2139: Wild type N-Ras, overexpressed in basal-like breast cancer, promotes tumor formation by inducing IL8 secretion via JAK2 activation

“Basal-like” breast cancer (BLBC) is the most aggressive breast cancer subtype, with a very poor prognosis _ median time to distant recurrence is just 2.6 years vs. 5 years overall, and survival time from diagnosis of distant metastatic disease is 9 months vs. 22 months. BLBC tumors usually do not express ER, Her2, or progesterone receptor. As such, they cannot be treated by the current targeted therapies, which target these molecules. What drive the formation and progression of BLBCs is largely unclear.

Ras GTPases are best known for mediating growth factor signaling, and oncogenic mutations in the RAS genes, and K-RAS in particular, are found in more than 30% of human tumors. Surprisingly, oncogenic RAS mutations are rare in breast cancer. However, we found that wild-type N-RAS is overexpressed in BLBCs, partly via promoter demethylation, but not in other breast cancer subtypes. Repressing N-RAS inhibits transformation and tumor growth, while overexpression enhances these processes even in preinvasive BLBC cells. In contrast, repressing N-RAS expression does not affect growth and transforming activities of breast cancer cells of other subtypes. We identified N-Ras-responsive genes, most of which encode chemokines, e.g., IL8. High expression levels of these N-Ras-responsive genes as well as of N-RAS itself in tumors correlate with poor patient outcome. N-Ras, but not K-Ras, induces IL8 by binding and activating the cytoplasmic pool of JAK2; IL8 then acts on both the cancer cells and stromal fibroblasts. Thus N-Ras drives BLBC by promoting transformation in epithelial cells, which in turn remodels the tumor microenvironment to create a proinvasive state.

These results illustrate an N-Ras-dependent convergence between the growth factor and cytokine pathways to enable efficient transformation of epithelial cells, which then orchestrate the remodeling of the tumor microenvironment. Although oncogenic mutations affecting RAS are common in many other human cancers, tumorigenesis in an important subset of breast cancers is driven instead by increasing activity of wild-type N-Ras. Thus, to fully assess the impact of Ras on tumorigenesis, the role of wild-type as well as mutant Ras proteins must be carefully examined.

Citation Format: Ze-Yi Zheng, Wen Bu, Lin Tian, Cheng Fan, Xia Gao, Cuijuan Yu, Liu Jun, Xiaomei Zhang, Yi-Hua Liao, Yi Li, Michael T. Lewis, Dean Edwards, Susan G. Hilsenbeck, Daniel Medina, Thomas P. Zwaka, Charles M. Perou, Chad J. Creighton, Xiang Zhang, Eric C. Chang. Wild type N-Ras, overexpressed in basal-like breast cancer, promotes tumor formation by inducing IL8 secretion via JAK2 activation. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 2139. doi:10.1158/1538-7445.AM2015-2139

Int6 reduction activates stromal fibroblasts to enhance transforming activity in breast epithelial cells

Background

The INT6 gene was first discovered as a site of integration in mouse mammary tumors by the mouse mammary tumor virus; however, INT6’s role in the development of human breast cancer remains largely unknown. By gene silencing, we have previously shown that repressing INT6 promotes transforming activity in untransformed human mammary epithelial cells. In the present study, guided by microarray data of human tumors, we have discovered a role of Int6 in stromal fibroblasts.

Results

We searched microarray databases of human tumors to assess Int6’s role in breast cancer. While INT6 expression levels, as expected, were lower in breast tumors than in adjacent normal breast tissue samples, INT6 expression levels were also substantially lower in tumor stroma. By immunohistochemistry, we determined that the low levels of INT6 mRNA observed in the microarray databases most likely occurs in stromal fibroblasts, because far fewer fibroblasts in the tumor tissue showed detectable levels of the Int6 protein. To directly investigate the effects of Int6 repression on fibroblasts, we silenced INT6 expression in immortalized human mammary fibroblasts (HMFs). When these INT6-repressed HMFs were co-cultured with breast cancer cells, the abilities of the latter to form colonies in soft agar and to invade were enhanced. We analyzed INT6-repressed HMFs and found an increase in the levels of a key carcinoma-associated fibroblast (CAF) marker, smooth muscle actin. Furthermore, like CAFs, these INT6-repressed HMFs secreted more stromal cell–derived factor 1 (SDF-1), and the addition of an SDF-1 antagonist attenuated the INT6-repressed HMFs’ ability to enhance soft agar colony formation when co-cultured with cancer cells. These INT6-repressed HMFs also expressed high levels of mesenchymal markers such as vimentin and N-cadherin. Intriguingly, when mesenchymal stem cells (MSCs) were induced to form CAFs, Int6 levels were reduced.

Conclusion

These data suggest that besides enhancing transforming activity in epithelial cells, INT6 repression can also induce fibroblasts, and possibly MSCs as well, via mesenchymal-mesenchymal transitions to promote the formation of CAFs, leading to a proinvasive microenvironment for tumorigenesis.

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.

Regulation of Ras localization and cell transformation by evolutionarily conserved palmitoyltransferases

Ras can act on the plasma membrane (PM) to mediate extracellular signaling and tumorigenesis. To identify key components controlling Ras PM localization, we performed an unbiased screen to seek Schizosaccharomyces pombe mutants with reduced PM Ras. Five mutants were found with mutations affecting the same gene, S. pombe erf2 (sp-erf2), encoding sp-Erf2, a palmitoyltransferase, with various activities. sp-Erf2 localizes to the trans-Golgi compartment, a process which is mediated by its third transmembrane domain and the Erf4 cofactor. In fission yeast, the human ortholog zDHHC9 rescues the phenotypes of sp-erf2 null cells. In contrast, expressing zDHHC14, another sp-Erf2-like human protein, did not rescue Ras1 mislocalization in these cells. Importantly, ZDHHC9 is widely overexpressed in cancers. Overexpressing ZDHHC9 promotes, while repressing it diminishes, Ras PM localization and transformation of mammalian cells. These data strongly demonstrate that sp-Erf2/zDHHC9 palmitoylates Ras proteins in a highly selective manner in the trans-Golgi compartment to facilitate PM targeting via the trans-Golgi network, a role that is most certainly critical for Ras-driven tumorigenesis.

Escorting Ras

Ras proteins are best known to function on the plasma membrane to mediate growth factor signaling. Controlling the length of time that Ras proteins stay on the plasma membrane is an effective way to properly modulate the intensity and duration of growth factor signaling. It has been shown previously that H- and N-Ras proteins in the GTP-bound state can be ubiquitylated via a K-63 linkage, which leads to endosome internalization and results in a negative-feedback loop for efficient signal attenuation. In a more recent study, two new Ras effectors have been isolated, CHMP6 and VPS4A, which are components of the ESCRT-III complex, best known for mediating protein sorting in the endosomes. Surprisingly, these molecules are required for efficient Ras-induced transformation. They apparently do so by controlling recycling of components of the Ras pathway back to the plasma membrane, thus creating a positive-feedback loop to enhance growth factor signaling. These results suggest the fates of endosomal Ras proteins are complex and dynamic — they can be either stored and/or destroyed or recycled. Further work is needed to decipher how the fate of these endosomal Ras proteins is determined.

Abstract 5074: Identification of Ras compartment-specific interacting proteins

Ras proteins are powerful molecular switches that control a wide range of functions, including cell growth, differentiation, apoptosis, cytoskeleton remodeling, etc. In humans, there are three RAS genes encode structurally highly similar Ras proteins that appear to have different functions in the cell. We have previously reported that a given Ras protein can signal from different cell compartments to control distinct functions in yeast. This present project aims to identify proteins that bind Ras in a cell compartment-specific manner in human cells to define how compartmentalized Ras signaling impacts tumor formation. We used the biomolecular fluorescence complementation (BiFC) method to screen a human cDNA library. Sixty two proteins were thus identified that bound the constitutively activated H-Ras (H-RasG12V), but not the GST control. These proteins also bound weakly to H-RasG12V whose effector binding motif has been mutated. To determine if these proteins can alter Ras functions, we first overexpressed them and then tested for their impacts on Ras-induced cell transformation and transcription. Only 25 of the isolated proteins could alter Ras signaling in these assays. Many of these 25 proteins are known to either associate with cellular membrane and/or regulate protein transportation, suggesting that as a group they highlight the importance of regulating Ras trafficking in the control of cell transformation. In particular, a number of isolated proteins may regulate endosome sorting, and we thus focused on two such proteins, CHMP6/VPS20 and VPS4A, for further investigation. We first validated the Ras binding by co-immunoprecipitation; furthermore the microscopy data showed that the binding is readily detectable in endosomes. Moreover, up- or down-regulating of level of either CHMP6/VPS20 or VPS4A dramatically inhibited Ras-induced transformation of NIH-3T3 cells. To determine how these molecules regulate Ras activities, we first examined whether they modulate Ras protein intracellular transport. Cell fractionation using sucrose gradients has shown that VPS4A knock-down could alter both wide-type and constitutively activated Ras membrane localization. In summary, we indentified Ras compartment-specific binding proteins by a cell-based approach. Many of the proteins are trafficking regulating proteins. In particular, two endosome sorting proteins CHMP6/VPS20 and VPS4A have been shown to regulate the oncogenic effects of Ras, possibly by localizing Ras proteins into proper cell compartments. We believe that the study of compartment-specific Ras interacting proteins is indispensable for better understanding the complex roles of Ras in oncogenesis of breast cancer as well as many other cancers.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 5074.

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.

Anti-estrogenic mechanism of unliganded progesterone receptor isoform B in breast cancer cells

Over half of breast cancer cases are estrogen-dependent and strategies to combat estrogen-dependent breast cancer have been to either block the activation of estrogen receptor (ER) or diminish the supply of estrogens. Our previous work documented that estrogen-independent expression of progesterone receptor (PR) in MCF-7 cells markedly disrupted the effects of estrogen. In this study, we have developed an adenovirus-mediated gene delivery system to study the specific involvement of PR isoform A (PR-A) and PR-B in the anti-estrogenic effect and its mechanism of action. The results revealed that PR-B, but not PR-A, exhibited distinct anti-estrogenic effect on E2-induced cell growth, gene expression, and ER-ERE interaction in a ligand-independent manner. The anti-estrogenic effect of PR-B was also associated with heightened metabolism and increased cellular uptake of estradiol-17 beta (E2). We have also found that the B-upstream segment of PR-B alone was able to inhibit E2-induced ER-ERE interaction and cellular uptake of E2. Although PR-A alone did not affect E2-induced ER activity, it antagonized the anti-estrogenic effect of PR-B in a concentration-dependent manner. The findings suggest an important mechanism of maintaining a favorable level of ER activity by PR-A and PR-B in estrogen target cells for optimal growth and differentiation. The potential anti-estrogenic mechanism of PR-B may be exploited for breast cancer therapy.

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.

A Novel Antiestrogenic Mechanism in Progesterone Receptor-transfected Breast Cancer Cells

The expression of progesterone receptor (PR) is normally estrogen-dependent, and progesterone is only active in target cells following estrogen exposure. This study revealed that the effect of estrogen was markedly disrupted by estrogen-independent expression of PR. Transfection of PR in estrogen receptor (ER)-positive MCF-7 cells abolished the estradiol-17beta growth stimulatory effect that was observed in the parental cells and the vector-transfected controls in a ligand-independent manner. The antiestrogenic effect was also observed at the level of gene transcription. Estradiol-17beta (E2)-induced gene expression of pS2 and GREB1 was impaired by 50-75% after 24-72 h of E2 treatment in PR-transfected cells. Promoter interference assay revealed that PR transfection drastically inhibited E2-mediated ER binding to estrogen response elements (ERE). The antiestrogenic effects of transfected PR are associated with enhanced metabolism of E2. HPLC analysis of [3H]E2 in the samples indicated that the percentage of [3H]E2 metabolized by PR-transfected cells in 6 h is similar to that by vector-transfected control cells in 24 h (77 and 80%, respectively). The increased metabolism of E2 may, in turn, be caused by increased cellular uptake of E2, as demonstrated by whole cell binding of [3H]E2. The findings open up a new window for a hitherto unknown functional relationship between the PR and ER. The antiestrogenic effect of transfected PR also provides a potential therapeutic strategy for estrogen-dependent breast cancer.

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.