[Analysis of clinical manifestations and prognosis of primary systemic light chain amyloidosis with liver involvement]

Objective: To summarize the clinical manifestations and prognostic factors of patients with hepatic amyloidosis in a single center. Methods: The clinical data of 28 primary systemic light chain amyloidosis cases with liver involvement in our center from October 2012 to January 2023 were retrospectively analyzed. The main clinical manifestations and prognostic factors were studied. Statistical analysis were performed using the χ(2) test, Fisher's exact test, Wilcoxon rank test, or Kaplan-Meier survival curve log-rank test according to the different data. Results: The main clinical manifestations of patients with liver involvement were abdominal distension, hepatomegaly, and edema. CD56 and chemokine receptor 4 protein expression accounted for 52% (13/25) and 56% (14/25). 64.3% (9/14) patients were combined with t (11,14), and 21.4% (3/14) patients were positive for 1q21 (+), and no patients were detected with del(17p). Univariate analysis showed that Mayo 2004 and 2012 stages and total bilirubin (TBil) ≥34.2 μmol/L were associated with progression-free survival and overall survival. The median progression-free survival and overall survival were significantly inferior in patients with TBil≥34.2μmol/L group (0.178 years, 0.195 years) than with the TBil<34.2μmol/L group (0.750 years, 3.586 years) (P < 0.05). Conclusion: Mayo stage and hyperbilirubinemia are inferior prognostic factors for patients with primary systemic light chain amyloidosis accompanied with liver involvement.

[Efficacy and safety of first-line treatment with anti-CD38 monoclonal antibody-based regimen for primary plasma cell leukemia]

Objective: To analyze the efficacy and safety of first-line treatment with an anti-CD38 monoclonal antibody regimen for primary plasma cell leukemia (pPCL). Methods: Patients diagnosed with pPCL from December 1st, 2018 to July 26th, 2023, receiving first-line treatment of anti-CD38 monoclonal antibody-based regimens across multiple centers including Peking University People's Hospital, Fuxing Hospital of Capital Medical University, Qingdao Municipal Hospital, Shengjing Hospital of China Medical University, Handan Central Hospital, the First Affiliated Hospital of Harbin Medical University, the Fourth Hospital of Hebei Medical University and General Hospital of Ningxia Medical University were consecutively included. A total of 24 pPCL patients were included with thirteen being male and eleven being female. The median age [M(Q1, Q3)] was 60 (57, 70) years. Patients were grouped according to peripheral blood plasma cell (PBPC) percentage [5%-19% (n=14) vs ≥20% (n=10)]. Last follow-up date was September 26th, 2023. The median follow-up period was 9.1 (4.2, 15.5) months. Patients' data related with clinical baseline characteristics, efficacy, survival and safety were retrospectively collected. Cox proportional hazards regression model was used to analyze risk factors associated with survival. Results: Among 24 pPCL patients, 16 (66.7%) patients had anemia at diagnosis, 13(54.2%) patients had thrombocytopenia, 8 (33.3%) patients had a baseline estimated glomerular filtration rate (eGFR)<40 ml·min-1·(1.73m2)-1, 13 (54.2%) patients had elevated lactate dehydrogenase (LDH) levels. The median PBPC percentage was 16% (8%, 26%) . Fluorescence in situ hybridization testing indicated that patients harboring 17p deletion, t(4;14) or t(14;16) were 6 (25.0%), 4 (16.7%) and 4 (16.7%), respectively. The overall response rate was 83.3% (20/24). The median progression-free survival (PFS) was 20.5 (95%CI: 15.8-25.2) months, and the median overall survival (OS) was not reached. Estimated 1-year and 2-year PFS and OS rates were 75.0% and 89.1%, 37.5% and 53.4%, respectively. The median PFS and OS for patients with PBPC percentages 5%-19% and≥20% were not reached and 20.5 (95%CI:15.7-25.3) months, 17.8 months and not reached, respectively. There was no significant statistical difference of PFS and OS between two groups (all P>0.05). Multivariate Cox regression analysis showed that 1p32 deletion was the risk factor associated with PFS (HR=7.7, 95%CI: 1.1-54.9, P=0.043). Seventeen patients (70.8%) developed grade 3-4 hematologic toxicities. Twelve patients (50.0%) developed grade 3-4 thrombocytopenia. Sixteen patients (66.7%) developed infection. All hematologic toxicities and infections were improved after supportive treatment. Conclusion: First-line treatment with anti-CD38 monoclonal antibody-based therapy for pPCL is effective and safe.

Ruggedized Self-Propelling Hemostatic Gauze Delivers Low Dose of Thrombin and Systemic Tranexamic Acid and Achieves High Survival in Swine With Junctional Hemorrhage

INTRODUCTION

Hemorrhage is responsible for 91% of preventable prehospital deaths in combat. Bleeding from anatomic junctions such as the groin, neck, and axillae make up 19% of these deaths, and reports estimate that effective control of junctional hemorrhage could have prevented 5% of fatalities in Afghanistan. Hemostatic dressings are effective but are time-consuming to apply and are limited when proper packing and manual pressure are not feasible, such as during care under fire. CounterFlow-Gauze is a hemostatic dressing that is effective without compression and delivers thrombin and tranexamic acid into wounds. Here, an advanced prototype of CounterFlow-Gauze, containing a range of low thrombin doses, was tested in a lethal swine model of junctional hemorrhage. Outcomes were compared with those of Combat Gauze, the current dressing recommended by Tactical Combat Casualty Care.

MATERIALS AND METHODS

CounterFlow-Gauze containing thrombin doses of 0, 20, 200, and 500 IU was prepared. Swine received femoral arteriotomies, and CounterFlow-Gauze was packed into wounds without additional manual compression. In a separate study using a similar model of junctional hemorrhage without additional compression, CounterFlow-Gauze containing 500 IU thrombin was tested and compared with Combat Gauze. In both studies, the primary outcomes were survival to 3 h and volume of blood loss.

RESULTS

CounterFlow-Gauze with 200 and 500 IU had the highest 3-h survival, achieving 70 and 75% survival, respectively. CounterFlow-Gauze resulted in mean peak plasma tranexamic acid concentrations of 9.6 ± 1.0 µg/mL (mean ± SEM) within 3 h. In a separate study with smaller injury, CounterFlow-Gauze with 500 IU achieved 100% survival to 3 h compared with 92% in Combat Gauze animals.

CONCLUSIONS

An advanced preclinical prototype of CounterFlow-Gauze formulated with a minimized thrombin dose is highly effective at managing junctional hemorrhage without compression. These results demonstrate that CounterFlow-Gauze could be developed into a feasible alternative to Combat Gauze for hemorrhage control on the battlefield.

[Efficacy and safety analysis of a combination regimen with BCL-2 inhibitor in relapsed/refractory primary systemic light chain amyloidosis with t(11;14) from a single center]

Objective: To explore the efficacy and safety of BCL-2 inhibitor-based treatment in patients with relapsed/refractory t (11; 14) primary systemic light chain amyloidosis. Methods: This was a retrospective case series study. Ten patients with relapsed/refractory t(11;14) primary systemic light chain amyloidosis who had all received treatment with a combination regimen including the BCL-2 inhibitor venetoclax from January 2018 to November 2022 at the Hematology Department of Peking University People's Hospital were included. Adverse events, and hematological and organ responses were evaluated. Results: The median age of the ten enrolled patients was 59 (range 41-78) years, and the male to female ratio was 8∶2. Except for one patient, a very good partial or better response was achieved in 8/9 patients and one patient obtained a partial response. The overall response rate was 100%. The median time to achieve a hematological response was 60 (range 24-236) days. At least one organ response was observed in 7/9 patients. With a median follow-up of 18 months, one patient experienced hematological progression and one patient died. Grade 3 adverse events included lymphocytopenia (3 cases), anemia (1 case), diarrhea (1 case), and appendicitis (1 case). One patient died of pulmonary fungal infection two months after completion of treatment, which was not excluded as being treatment related. Conclusion: A combination regimen including BCL-2 inhibitors in patients with relapsed/refractory t(11;14) primary systemic light chain amyloidosis is a potentially safe and effective treatment option that warrants further investigation.

Amplification of a terahertz wave via stimulated Raman scattering

Extremely strong terahertz (THz) waves are desperately demanded for investigating nonlinear physics, spectroscopy, and imaging in the THz range. However, traditional crystal-/semiconductor-based THz sources have limitations of reaching extremely high amplitude due to the damage threshold of devices. Here, by introducing Raman amplification to the THz range, we propose a novel, to the best of our knowledge, scheme to amplify THz waves in plasma. A long-pulse CO₂ pump laser transfers its energy to a multicycle, 10-THz seed in a two-step plasma. By one-dimensional simulations, a 0.87-GV/m, 1.2-ps-duration THz seed is amplified to 10 GV/m in a 5.7-mm-long plasma with an amplification efficiency approaching 1%. The method provides a new technology to manipulate the intensity of THz waves.

Efficacy and safety of CounterFlow in animal models of hemorrhage

LAY SUMMARY

The efficacy of current hemostatic technologies is limited by several factors. Outward blood flow washes hemostatic drugs away from the wound, and hemostatic drugs often require focus, training, and time to use correctly, are highly specific to one type of injury, or pose severe safety risks. CounterFlow is a novel product that could potentially save military and civilian lives by stopping heavy bleeding from a variety of organs and other bodily locations that current technology cannot easily treat. Upon contact with blood, CounterFlow releases bursts of gas to safely self-propel bio-degradable clot-forming and clot-stabilizing drugs against blood flow, delivering them to the source of bleeding. This unique mechanism allows CounterFlow to be applied quickly to a wide assortment of wounds and to act effectively with little management after application. CounterFlow was tested in multiple animal models representing common and deadly bleeding scenarios, including internal bleeding, care under fire without compression, and surgical bleeding, and it was found to outperform current care options by stopping bleeds faster and increasing survival times. CounterFlow is also safe to use and biocompatible. This narrative review summarizes studies testing the effectiveness and safety of CounterFlow, discusses useful applications, and describes future plans for the product.

Microsomal glutathione S-transferase 1 targets the autophagy signaling pathway to suppress ferroptosis in gastric carcinoma cells

OBJECTIVE

Ferroptosis is a newly discovered form of programmed cell death; however, the specific mechanisms that regulate ferroptosis have yet to be fully elucidated in gastric carcinoma. In this study, we aimed to investigate how microsomal glutathione S-transferase 1 (MGST1) regulates ferroptosis in gastric carcinoma cells.

METHODS

Gastric adenocarcinoma (SGC7901) cells that overexpressed MGST1 or expressed only low levels of MGST1, were treated with specific compounds (erastin, sorafenib, RSL3, MK-2206 and SC79). Then, we detected the levels of malondialdehyde (MDA), glutathione (GSH), iron and reactive oxygen species (ROS). Protein expression levels of the non-classical autophagy and protein kinase B (Akt)/glycogen synthase kinase-3β (GSK-3β) pathways were determined by western blotting and cell viability was analyzed by Cell Counting Kit-8 (CCK-8) assays. The expressions of target genes were detected using qRT-PCR.

RESULTS

We evaluated a range of ferroptosis-inducing compounds and found that MGST1 expression was down-regulated during ferroptosis in SGC7901 cells. The ferroptosis inducer RSL3 played a role in classical ferroptotic events while the overexpression of MGST1 impaired these effects. Interestingly, the overexpression of MGST1 resulted in the inactivation of autophagy by repressing the expression of ATG16L1 and the conversion of LC3-I to LC3-II. The upregulation of ATG16L1 eliminated the inhibitory action of MGST1 on ferroptosis. Notably, the overexpression of MGST1 induced the activation of the Akt/GSK-3β pathway. An Akt inhibitor antagonized the inhibitory effects of MGST1 on autophagy and ferroptosis.

CONCLUSION

Collectively, our findings demonstrate a novel molecular mechanism and signaling pathway for ferroptosis. We also characterized that the overexpression of MGST1 induces gastric carcinoma cell proliferation by activating the Akt/GSK-3β signaling pathway.

Repeat hepatic resection versus radiofrequency ablation for recurrent hepatocellular carcinoma: a retrospective multicentre study

BACKGROUND

The therapeutic value of repeat hepatic resection (rHR) or radiofrequency ablation (RFA) for recurrent hepatocellular carcinoma (HCC) is unknown. This study aimed to investigate the safety and efficacy of rHR or RFA.

METHODS

This was a retrospective multicentre study of patients with recurrent HCC within the Milan criteria who underwent rHR or RFA at nine university hospitals in China and Italy between January 2003 and January 2018. Survival after rHR or RFA was examined in unadjusted analyses and after propensity score matching (1 : 1).

RESULTS

Of 847 patients included, 307 and 540 underwent rHR and RFA respectively. Median overall survival was 73.5 and 67.0 months after rHR and RFA respectively (hazard ratio 1.01 (95 per cent c.i. 0.81 to 1.26)). Median recurrence-free survival was longer after rHR versus RFA (23.6 versus 15.2 months; hazard ratio 0.76 (95 per cent c.i. 0.65 to 0.89)). These results were confirmed after propensity score matching. RFA was associated with lower morbidity of grade 3 and above (0.6 versus 6.2 per cent; P < 0.001) and shorter hospital stay (8.0 versus 3.0 days, P < 0.001) than rHR.

CONCLUSION

rHR was associated with longer recurrence-free survival but not overall survival compared with RFA.

LINC00665 knockdown protects against cerebral ischemia-reperfusion injury

LINC00665 has been reported to participate in several human diseases. However, the role of LINC00665 in cerebral ischemia-reperfusion (CI/R) is still unknown. This study is designed to investigate the role of LINC00665 in rats with CI/R injury. We established middle cerebral artery occlusion/ reperfusion (MCAO/R) rats model in vivo. PC12 cells treated with oxygen-glucose deprivation/reperfusion (OGD/R) were used to establish in vitro I/R model. RT-qPCR assay was adopted to assess the mRNA expression of LINC00665 and miR-744-5p. MTT assay was used to determine cell viability. The protein expression of Bax and Bcl-2 were detected by Western blot assay. The relationship between LINC00665 and miR-744-5p was confirmed by dual luciferase reporter assay and RNA immunoprecipitation (RIP). In this study, we found that LINC00665 was sharply up regulated in MCAO/R rats and PC12 cells treated with I/R. Functionally, LINC00665 knockdown attenuated oxidative damage in PC12 cells treated with I/R. Moreover, LINC00665 knockdown promoted cell viability, while inhibited cell apoptosis in PC12 cells treated with I/R. In addition, miR-744-5p was confirmed to be a target of LINC00665. LINC00665 knockdown was validated to project CI/R injury by sponging miR-744-5p expression.

[Preparation of a novel tri-specific T cell engager targeting CD19 antigen and its anti-leukemia effect exploration]

Objective: To prepare a novel tri-specific T cell engager (19TriTE) targeting CD19 antigen, and to investigate its immunotherapeutic effect on CD19-positive hematological malignancies. Methods: 19TriTE was constructed by molecular cloning technology and successfully expressed through the eukaryotic expressing system. The effects of 19TriTE on the proliferation and activation of T cells, as well as the specific cytotoxicity against CD19 positive tumor cell lines were verified. Results: ①19TriTE expressing plasmid was constructed and successfully expressed through the eukaryotic expressing system. ②19TriTE can specifically bind to T cells and Nalm6 cells, with equilibrium dissociation constants of 19.21 nmol/L and 11.67 nmol/L, respectively. ③The expression rates of CD69 positive T cells and CD25 positive T cells were 35.4% and 49.8% respectively, when 2 nmol/L 19TriTE were added in the co-culture system, which were significantly higher than those in the control group. ④19TriTE can significantly promote the proliferation of T cells. The absolute count of T cells expanded from the initial one million to 74 million with an 74 fold increase at the concentration of 1 nmol/L on day 12. ⑤19TriTE can significantly mediate T cells killing of CD19 positive target cells in a dose-dependent manner. At the concentration of 10 nmol/L, the target cells lysis reached 50%. ⑥Degranulation experiment verified that 19TriTE can activate T cells in the presence of CD19 positive target cells, and the activation of T cells positively correlated with the dose of 19TriTE. ⑦When 19TriTE fusion protein co-cultured with T cells and target cells overexpression RFP and luciferase genes respectively, 19TriTE can notably mediate T cells killing of CD19 positive target cells through fluorescent microscope or bioluminescence imaging technology. Conclusion: In this study, we successfully constructed and expressed 19TriTE fusion protein and verified that it can effectively activate T cells and promote their proliferation in vitro. At the same time, it can bind to CD19 positive target cells and T cells, as well as enhance T cells anti-leukemia effect in vitro, providing the foundation for further clinical research.

[Observation of cosmetic effect of corneal interlamellar staining in patients with corneal leucoma]

Objective: To observe the clinical effect of corneal staining in patients with corneal leucoma. Methods: Restrospective case series study.Thirty eyes of 30 patients (17 males, 13 females) with corneal leucoma who underwent corneal interlamellar staining at Beijing Aier-Intech Eye Hospital from October 2014 to July 2018 were included. The mean age was 31.50±15.66 years. Postoperative follow-up was more than 1 year. All the patients underwent appearance examination, anterior segment examination with a slit lamp, B-scan examination and anterior segment OCT examination preoperatively and postoperatively. The effect of corneal staining, patient satisfaction and the incidence of complications were investigated. Results: The corneal epithelium of all the patients healed completely within 1-3 days after operation. The mean follow-up period was 30.68±18.02 months (range, 12.37-58.10 months). During the postoperative follow-up period, no staining permeation or inflammatory reaction in the anterior chamber occurred. The corneal color and appearance were well maintained in 18 patients (72.0%). Seven patients (28.0%) showed mild corneal color-fading. One patient was treated with enucleation and orbital hydroxyapatite implantation because of eye atrophy and corneal banding degeneration caused by the primary disease at 4 years after operation. The surgeon was satisfied with the improvement of the appearance of all cases; 22 patients (88.0%) were satisfied with the postoperative appearance. No significant complications were observed in all the cases. Conclusions: Corneal interlamellar staining is one of best choices for the treatment of corneal leucoma. It has advantages of quick postoperative recovery, long-standing color staining and good cosmetic effect. The operation is simple and easy to carry out and there is no obvious damage to eye tissues. (Chin J Ophthalmol, 2020, 56:465-472).

[Prognostic significance of flow cytometric minimal residual disease in acute myeloid leukemia during aplasia]

Objective: To investigate the impact of minimal residual disease (MRD) by multiparameter flow cytometry (MPFC) during aplasia on efficacy and prognosis of de novo acute myeloid leukemia (AML) (non M(3)) patients. Methods: The MRD data by 8-color MPFC during aplasia (day 14-15 of induction therapy) in 85 de novo AML (non M(3)) patients and the MRD impact on efficacy and prognosis were retrospectively analyzed. Results: Data of 85 patients, including 42 males (49.4%) and 43 females (50.6%) , were collected, with a median age of 35 (15-54) years. The median MRD by MPFC during aplasia was 0.58% (0-81.11%) , and 70 (82.4%) patients achieved complete remission (CR) after first induction chemotherapy. The cutoff of MRD by receiver operating characteristic (ROC) analysis was 2.305% (Se= 0.867, Sp=0.800) . The CR rate after one course was significantly higher in patients with MRD<2.305% [96.6% (56/58) ]than in patients with MRD≥2.305%[51.9% (14/27) ] (χ(2)=22.348, P<0.001) ; no significant difference with respect to relapse-free survival rate (χ(2)=1.08, P=0.299) or overall survival rate (χ(2)=0.42, P=0.516) could be demonstrated for the comparison of the two groups. Multivariates analysis showed MRD divided by 2.305% was the only independent prognostic factor for CR after one course (OR= 21.560, 95% CI 4.129-112.579, P<0.001) . Conclusion: Flow cytometric MRD divided by 2.305% during aplasia could be a predictor of efficacy after first induction therapy in AML patients.

Heterogeneous nuclear ribonucleoprotein E1 regulates protein disulphide isomerase translation in oxidized low-density lipoprotein-activated endothelial cells

AIMS

Endothelium-derived protein disulphide isomerase (PDI) is required for thrombus formation in vivo. But, how to control PDI overproduction in oxidized low-density lipoprotein (oxLDL)-activated vascular endothelial cells (VECs) is not well understood. In this study, we try to answer this question using our newly identified activator of mTOC1 3-benzyl-5-((2-nitrophenoxy) methyl)-dihydrofuran-2 (3H)-one (3BDO) that has been shown to protect VECs.

METHODS

First, we performed a proteomics analysis on the oxLDL-activated vascular VECs in the presence or absence of 3BDO. Next, we constructed the heterogeneous nuclear ribonucleoprotein E1 (hnRNP E1) mutants at Ser43 and used the RNA-ChIP technique to investigate the relationship between hnRNP E1 and PDI production. Furthermore, we examined the effect of 3BDO on oxLDL-altered phosphorylation of Akt1 and Akt2. Finally, we studied the effect of 3BDO on oxLDL-altered PDI protein level in apolipoprotein E(-/-) mice with advanced atherosclerosis.

RESULTS

In VECs, oxLDL-increased PDI protein level, induced hnRNP E1 phosphorylation at Ser43, suppressed the binding of hnRNP E1 to PDI 5'UTR and induced the phosphorylation of Akt2 but not Akt1. All of these processes were blocked by 3BDO. Importantly, Ser43 mutant of hnRNP E1 inhibited the increase of PDI protein level and the decrease of the binding of hnRNP E1 and PDI 5'UTR induced by oxLDL. Furthermore, 3BDO suppressed oxLDL-induced PDI protein increase in the serum and plaque endothelium of apolipoprotein E(-/-) mice.

CONCLUSION

hnRNP E1 is a new regulator of PDI translation in oxLDL-activated VECs, and 3BDO is a powerful agent for controlling PDI overproduction.

Enhanced hypotensive, bradycardic, and hypnotic responses to alpha2-adrenergic agonists in spinophilin-null mice are accompanied by increased G protein coupling to the alpha2A-adrenergic receptor

We previously identified spinophilin as a regulator of alpha(2) adrenergic receptor (alpha(2)AR) trafficking and signaling in vitro and in vivo (Science 304:1940-1944, 2004). To assess the generalized role of spinophilin in regulating alpha(2)AR functions in vivo, the present study examined the impact of eliminating spinophilin on alpha(2)AR-evoked cardiovascular and hypnotic responses, previously demonstrated to be mediated by the alpha(2A)AR subtype, after systemic administration of the alpha(2)-agonists 5-bromo-N-(4,5-dihydro-1H-imidazol-2-yl)-6-quinoxalinamine (UK14,304) and clonidine in spinophilin-null mice. Mice lacking spinophilin expression display dramatically enhanced and prolonged hypotensive, bradycardic, and sedative-hypnotic responses to alpha(2)AR stimulation. Whereas these changes in sensitivity to alpha(2)AR agonists occur independent of any changes in alpha(2A)AR density or intrinsic affinity for agonist in the brains of spinophilin-null mice compared with wild-type control mice, the coupling of the alpha(2A)AR to cognate G proteins is enhanced in spinophilin-null mice. Thus, brain preparations from spinophilin-null mice demonstrate enhanced guanine nucleotide regulation of UK14,304 binding and evidence of a larger fraction of alpha(2A)AR in the guanine-nucleotide-sensitive higher affinity state compared with those from wild-type mice. These findings suggest that eliminating spinophilin expression in native tissues leads to an enhanced receptor/G protein coupling efficiency that contributes to sensitization of receptor mediated responses in vivo.

High sensitivity SnO2 single-nanorod sensors for the detection of H2 gas at low temperature

Uniform SnO(2) nanorods were grown by inductively coupled plasma-enhanced chemical vapor deposition without catalysts and additional heating. The SnO(2) nanorods were aligned on a pair of Au/Ti electrodes by the dielectrophoresis method. SnO(2) single-nanorod gas sensors were fabricated by connecting individual SnO(2) nanorods to a pair of Au/Ti electrodes with Pt stripes deposited by a focused ion beam. The sensing properties of the SnO(2) single-nanorod sensor were studied. The SnO(2) single-nanorod sensor could detect 100 ppm H(2) at room temperature with repeated response and showed a large change of resistance, fast response time and good reversibility at an elevated operating temperature of 200 degrees C. The optimal sensing performance of the sensor is achieved at the operating temperature of around 250 degrees C.

Reduction of bacterial adhesion on ion-implanted stainless steel surfaces

The high incidence of infections caused by the use of biomedical devices has a severe impact on human health. An approach to reduce the complications is to modify the surface properties of biomedical devices. In this paper, stainless steel disks were implanted with N(+), O(+) and SiF(3)(+), respectively, by an ion implantation technique. The surface properties of the ion-implanted surfaces were characterized, including their surface chemical composition, roughness, topography, wettability and surface energy. Bacterial adhesion of Staphylococcus epidermidis and Staphylococcus aureus, which frequently cause medical device-associated infections was evaluated. The experimental results showed that these implanted stainless steels, particularly SiF(3)(+) implanted stainless steel performed much better than untreated stainless steel control on reducing bacterial attachment.

Role of nitric oxide in down-regulation of CYP2B1 protein, but not RNA, in primary cultures of rat hepatocytes

There are conflicting reports about the role of nitric oxide in the down-regulation of cytochrome P450 that occurs when animals or cultured hepatocytes are exposed to inflammatory stimuli. Here, we investigated the participation of NO in the down-regulation of CYP2B1 by bacterial endotoxin (LPS) in rat hepatocytes cultured on Matrigel. LPS caused the down-regulation of CYP2B1 mRNA to 20% of control values within 12 h of treatment, and this was not reversed by concentrations of NO synthase inhibitors that completely blocked NO production. LPS was several orders of magnitude more potent in the down-regulation of CYP2B1 mRNA than in induction of NO production. In contrast, concentrations of LPS in the 1 to 100 ng/ml range induced NO production and produced a rapid down-regulation of CYP2B1 protein to 30% and <5% of control at 6 and 24 h, respectively, that could be completely prevented both by inhibitors of NO synthase and by LY83583, which prevents NO synthase-2 induction. The blockade of CYP2B1 down-regulation by NO synthase inhibitors was reversed by arginine, and the NO donors S-nitrosoglutathione and S-nitroso-N-acetylpenicillamine mimicked CYP2B1 protein suppression. Taken together, these experiments demonstrate two independent mechanisms of CYP2B1 down-regulation by LPS: a rapid, NO-dependent suppression of the protein occurring at high concentrations of LPS and a slower, NO-independent pretranslational suppression occurring at low concentrations of LPS.

The role of the central nervous system in NaCl-sensitive hypertension in spontaneously hypertensive rats

The central and peripheral nervous system is typically considered to be a short-term modifier of sympathetic nervous system activity, but several lines of evidence suggest that they contribute to chronic elevation of arterial pressure in at least some forms of hypertension. Our studies focus on the mechanisms underlying NaCl-sensitive hypertension in the spontaneously hypertensive rat (SHR). When these rats are fed a high NaCl diet, their arterial pressure rapidly increases and is maintained about 30 mm Hg higher than those of pair fed controls. The increase in arterial pressure is associated with a decrease in norepinephrine release, specifically in the anterior hypothalamic nucleus (AHN), resulting in increased sympathetic nervous system activity, peripheral vasoconstriction, and arterial pressure. Furthermore, administration of an alpha2-adrenergic receptor agonist in this area blocks the NaCl-sensitive increase in arterial pressure in the SHR but has no significant effect on arterial pressure in normotensive controls. We have identified three intermediary steps by which dietary NaCl reduces AHN norepinephrine release. First, dietary NaCl causes an increase in plasma NaCl and a blunting of the plasma NaCl circadian rhythm. Second, alterations in plasma NaCl activate osmosensitive neurons in the organum vasculosum of the lamina terminalis (OVLT). Third, OVLT input to the AHN appears to increase the release of atrial natriuretic peptide with a resultant decrease in the local release of norepinephrine. Finally, our evidence demonstrates that these factors lead to an increased rise in sympathetic nervous system activity during the early wake phase in SHR on a high NaCl diet, contributing to NaCl-sensitive hypertension in SHR.

The organum vasculosum of the lamina terminalis regulates noradrenaline release in the anterior hypothalamic nucleus

Changes in either plasma sodium concentration or arterial pressure can differentially affect hypothalamic neurons. For instance, increases in plasma NaCl concentration decrease noradrenaline release from nerve terminals in the anterior hypothalamic nucleus, while increases in arterial pressure unrelated to an elevation in plasma NaCl enhance noradrenaline release in anterior hypothalamic nucleus. The present study tests the hypothesis that in the rat the organum vasculosum of the lamina terminalis (an osmosensitive area of the brain) detects rises in plasma NaCl concentration and conveys this information to anterior hypothalamic nucleus. The axons projecting from the organum vasculosum of the lamina terminalis to the hypothalamus were unilaterally cut immediately caudal to organum vasculosum of the lamina terminalis, and five days later, 3-methoxy-4-hydroxy phenylglycol (the major metabolite of noradrenaline in brain) was continuously monitored in the ipsilateral or contralateral anterior hypothalamic nucleus in response to an intravenous infusion of hypertonic saline. In spontaneously hypertensive rats, the infusion decreased the 3-methoxy-4-hydroxy phenylglycol concentration by 24+/-2% in the anterior hypothalamic nucleus contralateral to the lesion, and in control spontaneously hypertensive rats. In contrast, in the anterior hypothalamic nucleus ipsilateral to the lesion, hypertonic saline infusion caused a 58+/-3% increase in 3-methoxy-4-hydroxy phenylglycol. These data support the hypothesis that the organum vasculosum of the lamina terminalis is part of the circuit that transmits information concerning plasma NaCl concentration to anterior hypothalamic nucleus.

Circadian rhythm of plasma sodium is disrupted in spontaneously hypertensive rats fed a high-NaCl diet

High-NaCl diets elevate arterial pressure in NaCl-sensitive individuals, and increases in plasma sodium may trigger this effect. The present study tests the hypotheses that 1) plasma sodium displays a circadian rhythm in rats, 2) the plasma sodium rhythm is disturbed in spontaneously hypertensive rats (SHR), and 3) excess dietary NaCl elevates plasma sodium concentration in SHR. The results demonstrate that plasma sodium has a circadian rhythm that is inversely related to the circadian rhythm of arterial pressure. Although the plasma sodium rhythms of SHR and control rats are nearly identical, the plasma sodium concentrations are significantly higher in SHR throughout the 24-h cycle. Maintenance on a high-NaCl diet increases plasma sodium concentration similarly in both SHR and control rats, but it blunts the plasma sodium rhythm only in SHR. These results demonstrate that in rats, plasma sodium has a circadian rhythm and that high-NaCl diets increase plasma sodium concentration.

Evaluation of the Effect of Radiation Therapy to Nasopharyngeal Carcinoma by Positron Emission Tomography with 2-

Purpose: This investigation evaluated the effectiveness of positron emission tomography with 2-[F-18]fluoro-2-deoxy-D-glucose (PET-FDG) in assessing residual tumor or tumor recurrence in postradiation nasopharyngeal carcinoma (NPC) patients.Procedures: Forty-six patients with histologically proven NPC who received radiotherapy were included. PET-FDG images were analyzed by a semiquantitative method, metabolic ratio (tumor to cerebellum ratio).Results: The overall sensitivity and specificity of PET-FDG to detect residual tumors and recurrent lesions in the postradiation patients were 80% (12/15) and 87% (27/31), respectively. In patients with PET-FDG 6 months after radiation therapy, the sensitivity and specificity raised to 92% (11/12) and 100% (20/20), respectively.Conclusions: PET-FDG is effective in the evaluation of NPC treated with radiation. The optimal timing in assessing residual tumor or tumor recurrence in postradiation patients should be 6 months or later.

Analysis of extemporaneous alprostadil formulaions

Twenty-two extemporaneous alprostadil (PGE1) injection solutions samples from five different suppliers and three Caverject (Pharmacia and Upjohn, Inc., Bridgewater, NJ) samples from three different lots, all intended for the clinical treatment of erectile dysfunction, were analyzed to determine PGE1 concentration, assess formation of the PGE1 aqueous breakdown product (PGA1), define pH and assess active microbial contamination. High-pressure liquid chromatography (HPLC), pH meter and cell culture techniques were used to conduct the analyses. Of the 22 extemporaneously formulated samples, six showed PGE1 concentrations 10% greater than their listed amounts and seven showed PGA1 weight fractions corresponding to at least 1.5% of the total prostaglandidn content. It should be noted that no standard has been published in the United States Pharmacopeia/National Formulary for this preparation as of this date. All samples were within the pH range 4.5 to 6.0. Four samples tested positive for active microbial contamination. In adition, nearly all the extemporaneously formulated samples contained what appeared to be benzyl alcohol, and about one half had at least two other undefined peaks within their HPLC chromatograms. In contrast, all three Caverject samples were within +/- 7.5% of their listed PGE1 concentrations while showing PGA1 prostaglandins weight fractions of less 0.6%, all were within the pH range 4.0 to 4.5 and all tested negative for active microbial contamination. Chromatograms of the Caverject samples also diplayed peaks consistent with the presence of benzyl alcohol but did not exhibit addtional undefined peaks. The results suggest that significant variations in PGE1 concentration and in PGA1 formation, accompanied by the possibility of microbial contamination, can occur as a result of the extemporaneous formulation and subsequent transfer of this type of product as a premixed solution intended for treating erectile dysfunction.

Atrial natriuretic peptide regulation of noradrenaline release in the anterior hypothalamic area of spontaneously hypertensive rats

In spontaneously hypertensive rats (SHR), high NaCl diets increase arterial pressure and sympathetic nervous system activity by decreasing noradrenaline release in the anterior hypothalamic area (AHA), thereby reducing the activation of sympathoinhibitory neurons in AHA. Atrial natriuretic peptide (ANP) can inhibit the release of noradrenaline, and ANP concentration is elevated in the AHA of SHR. The present study tests the hypothesis that in SHR, local ANP inhibits noradrenaline release from nerve terminals in AHA. Male SHR fed a basal or high NaCl diet for 2 wk and normotensive Wistar Kyoto rats (WKY) fed a basal NaCl diet were studied. In SHR on the basal diet, microperfusion of exogenous ANP into the AHA elicited a dose-related decrease in the concentration of the major noradrenaline metabolite 3-methoxy-4-hydroxy-phenylglycol (MOPEG) in the AHA; this effect was attenuated in the other two groups. In a subsequent study, the ANP-C (clearance) receptor agonist c-ANP was microperfused into the AHA to increase extracellular concentration of endogenous ANP in AHA. c-ANP reduced AHA MOPEG concentration in SHR on the basal NaCl diet but not in the other two groups. These data support the hypothesis that local ANP inhibits noradrenaline release in the AHA and thereby contributes to NaCl-sensitive hypertension in SHR.

Anterior hypothalamic norepinephrine, atrial natriuretic peptide, and hypertension

Our laboratory has characterized a model of salt sensitive hypertension, the salt sensitive spontaneously hypertensive rat (SHR-S), in which dietary NaCl supplementation increases blood pressure by reducing norepinephrine release by nerve terminals in the anterior hypothalamic area (AHA), thus reducing activation of sympathoinhibitory neurons in the AHA. This, in turn, results in increased sympathetic outflow and higher blood pressure in the SHR. Two mechanisms have been shown to contribute to this effect: (i) reduced noradrenergic input into AHA via baroreflex pathways and (ii) local inhibition of NE release in AHA by the inhibitory neuromodulator atrial natriuretic peptide (ANP). Studies employing microinjection of a blocking monoclonal antibody to ANP directly into the AHA and the nucleus tractus solitarius (NTS) demonstrated for the first time that endogenous ANP in the brain is functionally active in the tonic control of blood pressure and baroreflex sensitivity in the SHR-S but plays a lesser role in the normotensive Wistar Kyoto (WKY) control. In the WKY, excitation of NTS neurons by baroreflex afferents leads to activation of sympathoinhibitory neurons in NTS and AHA, strong inhibition of sympathetic nervous system outflow, and a decrease in arterial pressure. In SHR-S, brain ANP acts at the levels of the NTS and the AHA to perturb this baroreflex regulatory pathway. ANP tonically activates sympathoinhibitory neurons in the caudal NTS of SHR-S, thereby restraining the rise in arterial pressure, and tonically inhibits baroreflex responsiveness to alterations in blood pressure. Thus ANP appears to act at a number of sites in brain to facilitate the development and maintenance of sympathetically mediated hypertension in the SHR-S model.

Acute saline infusion decreases norepinephrine release in the anterior hypothalamic area

Ingestion of a high NaCl diet elevates arterial pressure in spontaneously hypertensive rats, at least in part, by reducing the release of norepinephrine in the anterior hypothalamic area. The mechanism by which dietary NaCl excess alters anterior hypothalamic area norepinephrine release is unknown. Plasma Na+ is slightly elevated after ingestion of a meal; therefore, in the present study we tested the hypothesis that a small increase in plasma Na+ could reduce the release of norepinephrine in the anterior hypothalamic area and elevate arterial pressure. Male spontaneously hypertensive rats were randomized to be fed a diet containing either 1% (basal) or 8% (high) NaCl at age 7 weeks and were maintained on the diets for 2 weeks. Age-matched normotensive Wistar-Kyoto rats received a basal NaCl diet only. All rats were instrumented with a push/pull cannula, and 5 days later, the baseline release of 3-methoxy-4-hydroxyphenyl glycol (the major metabolite of norepinephrine in brain) was measured in awake, freely moving rats. Rats were then challenged with an intravenous infusion (75 microL/min) of hypertonic (2.7%) saline for 20 minutes. In spontaneously hypertensive rats fed a basal NaCl diet, the hypertonic saline infusion elevated mean arterial pressure by 12% and reduced the concentration of the norepinephrine metabolite in the anterior hypothalamic area by 19%; these alterations persisted after termination of the hypertonic saline infusion. Spontaneously hypertensive rats maintained on the high NaCl diet showed greatly reduced arterial pressure and norepinephrine metabolite responses. In normotensive control rats compared with the hypertensive rats fed the basal NaCl diet, the hypertonic saline had considerably less effects on arterial pressure and norepinephrine metabolite levels in the anterior hypothalamic area, and the responses were significantly shorter. Thus, a small elevation in plasma Na+ can reduce the release of norepinephrine in the anterior hypothalamic area. This response is greatly exaggerated in spontaneously hypertensive rats fed a basal (but not a high) NaCl diet, suggesting that a postprandial rise in NaCl could initiate the fall in norepinephrine and thereby contribute to the rise in arterial pressure in spontaneously hypertensive rats ingesting a high NaCl diet.

Studies on the distribution of vasopressin-immunoreactive neuronal perikarya and their fibers in the hypothalamus of Tupaia belangeri

The distribution of vasopressin (VP)-immunoreactive neuronal perikarya and its fibers had been studied in the hypothalamus of Tupaia belangeri using the avidin-biotin complex (ABC) immunocytochemical technique. VP-immunoreactive neurons were found in the hypothalamic paraventricular nucleus (PVN), supraoptic nucleus (SON), accessory supraoptic nucleus (ASN), hypothalamic lateral nucleus (HLN), perifornical nucleus (PFN) and ansa peduncularis (AP) but not in the suprachiasmatic nucleus (SCN). VP neurons of the rostral PVN could be divided into three subnuclei and the caudal PVN could also be divided although not so distinctly into four subnuclei. The VP-immunoreactive neuronal perikarya of SON were divided into three parts, i.e., medioventral, mediodorsal and laterodorsal. Three types of VP neuronal perikarya, i.e., large, medium and small cells, existed in PVN and SON. Between PVN and SON, there were a large number of VP immunopositive nerve fibers. In addition, there were numerous immunopositive fibers projecting into the infundibulum and the neurohypophysis. VP-immunoreactive-positive products localized in the large granular vesicles and on the rough-surfaced endoplasmic reticulum could be seen under electron microscope.

Acute hypertension increases norepinephrine release in the anterior hypothalamic area

Neurons in the anterior hypothalamic area play an important role in NaCl-sensitive hypertension in spontaneously hypertensive rats, and previous studies have suggested that baroreceptor feedback modifies the activity of these neurons. To test the hypothesis that the release of norepinephrine in the anterior hypothalamic area is modified by arterial baroreceptor reflex feedback and that this reflex release is disturbed in spontaneously hypertensive rats on a high NaCl diet, we used the push-pull technique to measure the release of the norepinephrine metabolite 3-methoxy-4-hydroxy-phenylglycol in the anterior hypothalamic area. Seven-week-old male spontaneously hypertensive and normotensive Wistar-Kyoto rats were placed on a high (8%) or a basal (1%) NaCl diet for 2 weeks. The high NaCl diet elevated mean arterial pressure and greatly reduced basal norepinephrine metabolite levels in the anterior hypothalamic area of the spontaneously hypertensive (but not the control) rats (305 +/- 32 pg/10 min in the rats consuming 1% NaCl and 93 +/- 9 pg/10 min in the rats consuming 8% NaCl). An infusion of tramazoline (an imidizoline that causes long-lasting hypertension) that increased arterial pressure by 25 mm Hg elevated anterior hypothalamic area norepinephrine metabolite concentrations significantly more in the spontaneously hypertensive rats on the 1% NaCl diet (to 392 +/- 46 pg/10 min) than in those on the 8% NaCl diet (to 113 +/- 18 pg/10 min). In contrast, in Wistar-Kyoto rats the tramazoline-induced increase in arterial pressure elevated anterior hypothalamic area norepinephrine metabolite concentrations slightly more in rats on the 8% NaCl diet than in those on the 1% NaCl diet.(ABSTRACT TRUNCATED AT 250 WORDS)