[Comparison of the anesthetic effects of mivacurium and cisatracurium besylate in laser laryngeal microsurgery].

Objective: To compare the anesthetic effects of mivacurium and cisatracurium besylate in laser laryngeal microsurgery, and to provide clinical evidence and reference for further optimization of muscle relaxation application. Methods: From October 2021 to January 2022, fifty-six patients of Beijing Tongren Hospital, Capital Medical University, scheduled for laser laryngeal microsurgery with general anesthesia, were enrolled. These patients, aged 18-65 years old, 25 males and 31 females, were divided into two groups (n=28) by random number table method. Cisatracurium besylate group (group C): cisatracurium besylate was injected at 0.1 mg/kg. Normal saline was continuously infused during operation. Mivacurium group (group M):Mivacurium was injected at 0.25 mg/kg and continuously infused at 0.3 mg·kg-1·h-1 during operation.The intubation time, the extubation time, recovery index, Cooper's score, Cormack-Lehane grade, surgical condition grade, postoperative residual neuromuscular block and allergic related adverse events were compared between the two groups. Results: The intubation time and the extubation time of group M were (3.7±1.1) and (16.2±5.0) min, which were statistically significant shorter than those of group C (4.9±0.7) and (26.4±8.6) min (all P<0.05). The recovery indexes of the patients in group M and group C were (4.5±3.4) and (6.2±5.0) min. The Cooper's scores of the two groups were both 9(9, 9). The Cormack-Lehane grades of the two groups were all grade Ⅰ. The number of cases with good/excellent surgical condition grades in group M and group C were 5/23 and 0/28. There were no significant differences in recovery index, Cooper's score, Cormack-Lehane grades and surgical condition grades between the two groups (all P>0.05). The TOF ratio of group M in the post anesthesia care unit (PACU) was (95.7±2.6) %, which was significantly higher than (92.9±3.9) % of group C(P=0.015). There were no significant differences in MAP and HR between the two groups at different time points (all P>0.05). The incidence of skin flushing in group M and group C was 10.7% (3/28) and 0, and the difference was not statistically significant (P=0.074). There were no cases of severe hypotension, significantly elevated airway pressure or airway spasm in both groups. Conclusion: In laser laryngeal microsurgery, compared with cisatracurium besylate, mivacurium has shorter intubation time and extubation time, stable hemodynamics, no significant increase in allergic related adverse events. mivacurium is safe and effective.

[Quantitative hepatitis B core antibody levels can be used as a predictive index of HBsAg clearance].

Objective: To explore the possibility of hepatitis B core antibody (anti-HBc) in predicting hepatitis B virus surface antigen (HBsAg) clearance. Methods: Sixty cases with chronic hepatitis B who were previously treated with peginterferon α-2a combined with nucleos(t)ide analogues (NAs) antiviral therapy were divided according to the HBsAg clearance or non-clearance; 41 cases in the clearance group and 19 cases in the non-clearance group. Double antigen sandwich method was used to detect patients anti-HBc quantitative levels during the course of treatment and at baseline, 24, 48, 72 and 96 weeks. Logistic regression analysis and receiver operating characteristic curve (ROC) were used to evaluate the predictive ability of related influencing factors for HBsAg clearance. Results: With antiviral treatment prolongation, anti-HBC quantitative levels in the overall population showed a progressive downward trend in the clearance group and the non-clearance group, but the anti-HBC level in the clearance group was significantly higher than non-clearance group at the baseline and successive detection time points during the antiviral treatment (P < 0.05). Multivariate logistic regression showed that baseline quantitative anti-HBC level, HBsAg decline at week 24 (log10 IU / ml), and alanine aminotransferase (ALT) > 1.5 times the upper limit of normal value (ULN) were all influencing factors for HBsAg clearance during the treatment (OR = 0.156, P = 0.026; OR = 0.134, P = 0.023; OR = 0.239, P = 0.028). Among them, the baseline quantitative anti-HBc level was the best independent predictor for HBsAg clearance (OR = 0.235; P = 0.004), and the sensitivity and specificity for predicting HBsAg clearance at > 3.40 log10 IU/ mL were 56.1% and 89.5%, respectively. Logistic regression model was used as a reference to construct combined predictors in order to improve the prediction accuracy. Among them, the combined factor 3 had the highest predictive value (the area under the ROC curve had reached up to 0.870; 95%CI was 0.781 ~ 0.960; P < 0.001). The cut-off value of combined factor 3 was > 0.386, and the sensitivity and specificity were 80.5% and 78.9%, respectively. In addition, the combined index had further improved the predictive value, which is the combination of any two or more indexes based on the baseline quantitative anti-HBC level, and HBsAg clearance predictive rate had reached 94.12% ~ 100%. Conclusion: The baseline quantitative anti-HBC level has the highest predictive value for HBsAg clearance. The combination of ALT > 1.5×ULN and HBsAg decline at 24 weeks during the treatment can more precisely predict HBsAg clearance. Therefore, it is a reliable non-invasive biomarker.

[Clinical study on liver function, virology, serological changes and the safety of drug withdrawal in pregnant women who are chronic HBV carriers during pregnancy and postpartum].

Objective: To observe the changes of liver function, virology and serology and the safety of drug withdrawal in pregnant women who are chronic hepatitis B virus (HBV) carriers. Methods: A prospective clinical cohort was established to enroll pregnant women who are chronic HBV carriers and they were divided into the nucleoside/nucleotide analogs (NAs) intervention group and the non-NAs intervention group according to patients' wishes. Liver function, HBV DNA and HBV serological markers were detected at gestation, postpartum 6 weeks, 12 weeks, 24 weeks, 36 weeks and 48 weeks. Results: 351 patients were enrolled, 320 in the NAs intervention group and 31 in the non-NAs intervention group. The proportion of postpartum hepatitis flares in both groups was higher than that in pregnancy (39.4% vs 12.5%, P < 0.001; 38.7% vs 3.2%, P = 0.001). Six weeks postpartum was the peak period of hepatitis flares, and 96.0% (121/126) of the hepatitis flares occurred within 24 weeks postpartum. At 6 weeks postpartum, there were 6 cases of alanine aminotransferase (ALT) ≥ 10 times upper limit of normal (ULN) in the NAs intervention group. The rate of the hepatitis flare after drug withdrawal was 16.7% (34/203). Conclusion: Regardless of the presence or absence of NAs intervention, pregnant women who are chronic HBV carriers have a certain proportion of hepatitis flares during pregnancy and postpartum, and the hepatitis flare even have a tendency to be severe. Therefore, drug withdrawal after delivery is not always safe, which requires close observation and classification. At 6 weeks postpartum, the incidence of hepatitis flares was high, and those who meet the treatment indications can get better therapeutic effects if given appropriate treatment. The vast majority (96%) of postpartum hepatitis flares occur within 24 weeks, so it is recommended to follow up to at least 24 weeks postpartum after discontinuation.

Role of HMGB1 in Post-traumatic Endoplasmic Reticulum Stress in Rat Lung Tissues.

OBJECTIVES: To explore the role of high mobility group B1 （HMGB1） protein in the post-traumatic endoplasmic reticulum stress （ERS） in rat lung tissues. METHODS: The rat model of acute lung injury was established by crushing the hind limbs of rats with standard weight. The first experiment was to divide rats into postural control group and crush groups （6 h, 18 h and 30 h after crushing）. The second experiment was to divide rats into postural control group, 18 h crush group, HMGB1 inhibitor sodium butyrate （SB） group and 18 h crush+SB group. The protein expression changes of HMGB1 and ERS- related proteins （GRP78, caspase-12, CHOP and IRE1α） in rat lung tissues were detected with Western blotting. Meanwhile, the pathological changes of rat lungs were observed by HE stain. RESULTS: Compared with the postural control group, the expression levels of ERS-related proteins （GRP78, caspase-12, CHOP and IRE1α） and HMGB1 protein in rat lung tissues by crushing the hind limbs of rats were obviously increased. The protein levels reduced at 30 h after crushing but were still higher than those of postural control group and obvious pathological changes of acute lung injury were observed simultaneously in rats. Compared with the 18 h crush group, the expression levels of the ERS-related proteins and HMGB1 protein in rat lung tissues were attenuated in 18 h crush+SB group, and the pathological changes of rat lung injury began to alleviate. CONCLUSIONS: HMGB1-ERS pathway activated by traumatic stress can lead to acute lung injury in rats.

[Low-levels of HBsAg quantification at 48-week in HBeAg-negative chronic hepatitis B patients are the advantageous population for HBsAg clearance].

Objective: To analyze the therapeutic effect on HBeAg-negative chronic hepatitis B patients treated with Peg-IFNα-2a combined with NAs to obtain the influencing factors for predicting HBsAg clearance. Methods: A retrospective study was conducted to investigate the effect of pegylated interferon alpha-2a combined with nucleoside analogues (lamivudine/adefovir dipivoxil) on HBeAg-negative chronic hepatitis B. The treatment course was 96 weeks. Patients were followed up 120 weeks after the treatment. HBsAg clearance at 120 weeks was taken as the objective of the study. Logistic regression and receiver operating characteristic curve analysis screened the related factors affecting HBsAg clearance. χ (2) test was used to compare count data. Results: 111 patients were treated with pegylated interferon alpha-2a combined with nucleoside analogues, and 107 patients completed the scheduled course of treatment and follow-up. HBsAg clearance rate at120 week was 29.0% (31/107). The influencing factors for analysis were: (1) gender had no effect on HBsAg clearance rate; age and baseline levels of HBV DNA and alanine aminotransferase had no significant effect on HBsAg clearance; low baseline level of HBsAg (< 3.023 lgIU/ml) was beneficial to HBsAg clearance. The area under the working characteristic curve of the subjects was 0.746, the positive predictive value was 44.4%, and the negative predictive value was 86.8%. (2) HBsAg quantification or decline in 24 weeks and 48 weeks of treatment had a good predictive effect on HBsAg clearance, and the 48 weeks predicted value was higher than 24 weeks. When the HBsAg quantification was≤2.070 lgIU/ml at 48 weeks, the area under the receiver operating characteristic curve was 0.931, the positive predictive value was 52.8%, and the negative predictive value was 94.4%. When HBsAg decreased from baseline to≥0.991 lgIU/ml, the area under the receiver operating characteristic curve was 0.888, the positive predictive value was 50.8%, and the negative predictive value was 97.9%. (3) The analysis of HBsAg subgroup levels at 48 weeks suggested that the "interval analysis" can forecast HBsAg clearance more exactly than "nodal analysis" .The final HBsAg clearance rate of 100 IU/ml < HBsAg≤1 000 IU/ml, 10 IU/ml < HBsAg≤100 IU/ml and HBsAg≤10 IU/ml groups reached 6.7%, 31.8% and 67.7%, respectively. (4) The ALT abnormal group in the course of treatment obtained a higher HBsAg clearance rate (48.0%, 12/25). Conclusion: 96-weeks long-term treatment with pegylated interferon-alpha -alpha-2a combined with nucleoside analogues for HBeAg-negative chronic hepatitis B has a good predictive value for HBsAg clearance at baseline and during treatment. The "interval level" of HBsAg at 48-weeks is more accurate in predicting HBsAg clearance, suggesting that HBeAg-negative chronic hepatitis B patients with low HBsAg levels at 48-weeks are the advantageous populations with HBsAg clearance. These patients are worthy of prolonged treatment to pursue "clinical cure".

Extra green light induced ZnO ultraviolet lasing enhancement assisted by Au surface plasmons.

We observed the dramatic enhancement of the intrinsic spontaneous and stimulated emission as well as the ensuing suppression of defect-related green emission in Au-decorated ZnO microrods. A series of spectral experiments and theoretical analysis demonstrated an electron transfer assisted process by surface plasmon (SP) resonant coupling between the Au nanoparticles and ZnO. The mechanism indicates an approach to enhance the UV emission of ZnO through an extra excitation of visible light similar to that for the defect emission of ZnO. Based on the coupling mechanism, the externally enhanced ultraviolet lasing was further improved from 1.5 to 2.8-fold by adjusting the pumping power of the green light intensity in the Au/ZnO hybrid cavity. This research not only further confirms the SPR-assisted electron transfer process but also offers an approach to improve the intrinsic UV emission even for heavily-defected ZnO through visible light excitation via a nonlinear process.

Real-Time Motor Cortex Mapping for the Safe Resection of Glioma: An Intraoperative Resting-State fMRI Study.

BACKGROUND AND PURPOSE: Resting-state functional MR imaging has been used for motor mapping in presurgical planning but never used intraoperatively. This study aimed to investigate the feasibility of applying intraoperative resting-state functional MR imaging for the safe resection of gliomas using real-time motor cortex mapping during an operation. MATERIALS AND METHODS: Using interventional MR imaging, we conducted preoperative and intraoperative resting-state intrinsic functional connectivity analyses of the motor cortex in 30 patients with brain tumors. Factors that may influence intraoperative imaging quality, including anesthesia type (general or awake anesthesia) and tumor cavity (filled with normal saline or not), were studied to investigate image quality. Additionally, direct cortical stimulation was used to validate the accuracy of intraoperative resting-state fMRI in mapping the motor cortex. RESULTS: Preoperative and intraoperative resting-state fMRI scans were acquired for all patients. Fourteen patients who successfully completed both sufficient intraoperative resting-state fMRI and direct cortical stimulation were used for further analysis of sensitivity and specificity. Compared with those subjected to direct cortical stimulation, the sensitivity and specificity of intraoperative resting-state fMRI in localizing the motor area were 61.7% and 93.7%, respectively. The image quality of intraoperative resting-state fMRI was better when the tumor cavity was filled with normal saline (P = .049). However, no significant difference between the anesthesia types was observed (P = .102). CONCLUSIONS: This study demonstrates the feasibility of using intraoperative resting-state fMRI for real-time localization of functional areas during a neurologic operation. The findings suggest that using intraoperative resting-state fMRI can avoid the risk of intraoperative seizures due to direct cortical stimulation and may provide neurosurgeons with valuable information to facilitate the safe resection of gliomas.

Detection methods of Cyprinid herpesvirus 2 infection in silver crucian carp (Carassius auratus gibelio) via a pORF72 monoclonal antibody.

Cyprinid herpesvirus 2 (CyHV-2) is the main pathogen responsible for causing haematopoietic necrosis disease in Carassius auratus gibelio. Although many nucleic acid-based diagnostic methods have been applied, no stable and sensitive immunological diagnostic approaches have been reported. In this study, to detect CyHV-2 in clinical samples using immunological methods, recombinant ORF72 protein (pORF72), encoded by the CyHV-2 ORF72 gene, was used as a capture antigen to identify blood and tissues infected with CyHV-2. First, ORF72 gene was amplified from the CyHV-2 genome and cloned into a PGEX-4t-3 expression vector to produce pORF72 in Escherichia coli. The purified pORF72 was used as an immunogen to prepare monoclonal antibodies. The Western blotting assays revealed that the monoclonal antibody could specifically identify the pORF72. Furthermore, an immunohistochemical protocol and a blood smear method were established to detect CyHV-2 in carps. The results indicate that the monoclonal antibody against pORF72 could be utilized as an effective detection tool for haematopoietic necrosis disease in Carassius auratus gibelio.

[Long-term clinical effect and safety observation of sublingual dermatophagoides farinae drop in preschool and school-age children with allergic rhinitis].

Objective:To evaluate the efficacy of specific sublingual immunotherapy (SLIT) with Dermatophagoides farinae drops on preschool and school age children with allergic rhinitis.Method:Fifty preschool children (≤6 year), and 52 school age children (> 6 year), who suffered from dust mite induced allergic rhinitis, were randomly divided into subingual immunotherapy (SLIT) + drug group and drug group. SLIT + drug group was treated with a standardized subingual immunotherapy drops of Dermatophagoides farinae and combined with symptomatic therapy, drug group was treated with mometasone furoate nasal spray and dseloratdine tablets as symptomatic treatment. These children were followed up for 2 years with one visit in every 3 months. Symptom scores and medication scores were record at each visit. Comprehensive evaluation of symptom, medication, and patients' degree of satisfaction were used.Result:Two years after SLIT finished, symptom scores (SLIT + drug group: 1.13±1.05; drug group: 4.68±3.09), medication scores (SLIT + drug group: 0.07±0.04; drug group: 0.36±0.25) of SLIT+drug group were significantly lower than those in drug group respectively, all P< 0.01. The subjective assessment of patient' symptom, medication, and treatment satisfaction in SLIT+drug group was significantly lower than those in drug group. Subjective assessment symptoms, medication, and treatment satisfaction in preschool group was the same as in school age group. After SLIT ended for 2 years, subjective assessment and treatment satisfaction in the school age group was better than those in preschool group in medication score.Conclusion:SLIT demonstrated clinical improvement in children of different ages during 2 years treatment. the symptom scores, medication scores and subjective satisfaction in school age group are better than those in preschool group.

Lasing mode regulation and single-mode realization in ZnO whispering gallery microcavities by the Vernier effect.

The wide direct bandgap and strong exciton binding energy of ZnO have inspired examinations of ultraviolet lasing over the previous decades. However, regulation of the lasing mode, especially the realization of single mode lasing, is still a challenge. In this study, a ZnO comb-like structure with an array of microrods was selected to design coupled whispering-gallery-mode cavities, wherein the naturally varied air-gap between the adjacent microrods created a flexible condition for optical field coupling without any complicated micromanipulation. Spectral behaviour of lasing and coupling interaction between coupled ZnO microrods were systematically investigated. By regulating the nano-scale inter-space of dual coupled microrods, stable single-mode lasing with a higher Q factor and lower threshold was obtained successfully based on the Vernier effect. The formation conditions and the mechanism of single-mode lasing derived from the coupled ZnO microrods were discussed in detail. It also demonstrated an approach to construct high quality single-mode lasing by tuning the diameters of the coupled ZnO microrods.

Highly efficient production of hyaluronic acid by Streptococcus zooepidemicus R42 derived from heterologous expression of bacterial haemoglobin and mutant selection.

UNLABELLED: During Streptococcus zooepidemicus fermentation, most carbon sources are used to synthesize lactic acid, which can inhibit strain growth and hyaluronic acid production. Here, we expressed bacterial haemoglobin (Vhb) in Strep. zooepidemicus. Due to highly efficient oxygen use, only 15·26 g l(-1) lactic acid was produced, which is 0·73 times the quantity produced by the control strain. Compared with the control strain (1·61 g l(-1) ), hyaluronic acid (HA) production in this strain did not substantially increase, only to 2·16 g l(-1) . Next, we used a series of N-methyl-N'-nitro-N-nitroso-guanidine (NTG) treatments and selection programmes. Finally, we generated a hyaluronidase-negative and rifampin-resistant mutant strain that produces high levels of HA. The optimum carbon concentration for maximum hyaluronic acid production is only 30 g l(-1) of sucrose, which is lower than the control strain (60 g l(-1) ). The oxygen transfer rate coefficient KL a increased significantly to 372 ± 53 h(-1) from 18 ± 4 h(-1) of the control. The optimum carbon source for this strain is 21 g l(-1) of sucrose, 9 g l(-1) of maltose and 5 g l(-1) of glutamic acid. Hyaluronic acid accumulated at 6·7 g l(-1) in the culture broth. However, the molecular weight of HA decreased from 1835 KDa (Control) to 429 kDa. The prepared low-molecular weight HA could function as potential antiangiogenic substances, antiviral and antitumour agents to possibly be used as functional food ingredients. SIGNIFICANCE AND IMPACT OF THE STUDY: Hyaluronic acid (HA) has been used for a wide range of applications in health, cosmetic and clinical fields. During fermentation of Streptococcus to produce HA, 80-85% of the carbon source is used to produce lactic acid and acetic acid, and only approx. 5 and 10% of the carbon source is used to produce HA and biomass respectively. Here, we expressed bacteria haemoglobin (Vhb) in Streptococcus zooepidemicus, which can dramatically inhibit lactic acid production. After NTG treatments and selection programmes, we identified a mutant strain with highly efficient hyaluronic acid production (6·7 g l(-1) ) under economic fermentation conditions.

Protective effects of thrombomodulin on microvascular permeability after subarachnoid hemorrhage in mouse model.

The enhanced vascular permeability is a major early brain injury following subarachnoid hemorrhage (SAH). However, its mechanism is not clear yet. In this work, we explored its potential mechanism and investigated the roles of thrombomodulin (TM) in maintaining microvascular integrity after SAH. SAH models were established in adult male ICR mice (28-32 g) by endovascular perforation. TM was immediately administered by femoral vein injection following SAH. The brain water content, Evans Blue content and neurological functions were evaluated. Brain edema was also detected by magnetic resonance imaging (MRI) (T2 map). The siRNA technique, enzyme-linked immunosorbent assay (ELISA), immunofluorescence staining and western blotting were performed to explore the potential mechanism of TM treatment. The number of microthrombi in the hippocampus microvessels was also recorded. TM significantly decreased brain water content and Evans Blue content, alleviated brain edema and neurological deficits after SAH. The plasma concentration of activated protein C was increased after TM treatment. In addition, the levels of phospho-p38MAPK, phospho-p53, cleaved caspase-3, phospho-NF-κB (p65) were markedly decreased. Additionally, the loss of VE-cadherin and Occludin (markers of vascular integrity) and the number of microthrombi in the hippocampus were also reduced. Our results indicated that TM has protective effects on preserving microvascular integrity following SAH partly through preserving endothelial junction proteins and quenching apoptosis/inflammation in endothelial cells via blocking p38MAPK-p53/NF-κB (p65) pathway.

Exploratory modeling and simulation to support development of motesanib in Asian patients with non-small cell lung cancer based on MONET1 study results.

The motesanib phase III MONET1 study failed to show improvement in overall survival (OS) in non-small cell lung cancer, but a subpopulation of Asian patients had a favorable outcome. We performed exploratory modeling and simulations based on MONET1 data to support further development of motesanib in Asian patients. A model-based estimate of time to tumor growth was the best of tested tumor size response metrics in a multivariate OS model (P < 0.00001) to capture treatment effect (hazard ratio, HR) in Asian patients. Significant independent prognostic factors for OS were baseline tumor size (P < 0.0001), smoking history (P < 0.0001), and ethnicity (P < 0.00001). The model successfully predicted OS distributions and HR in the full population and in Asian patients. Simulations indicated that a phase III study in 500 Asian patients would exceed 80% power to confirm superior efficacy of motesanib combination therapy (expected HR: 0.74), suggesting that motesanib combination therapy may benefit Asian patients.

Simulations using a drug-disease modeling framework and phase II data predict phase III survival outcome in first-line non-small-cell lung cancer.

Simulations were performed for carboplatin/paclitaxel (C/P) plus motesanib or bevacizumab vs. C/P as first-line treatment for advanced non-small-cell lung cancer (NSCLC) using a published drug-disease model. With 700 patients in each arm, simulated hazard ratios for motesanib (0.87; 95% confidence interval [CI], 0.71-1.1) and bevacizumab (0.89; 95% CI, 0.73-1.1) agreed with results from the respective phase III studies but did not discriminate between failed and successful studies. The current model may require further enhancement to improve its utility for predicting phase III outcomes.

CFTR (TG)m(T)n polymorphism in patients with CBAVD in a population expressing low incidence of cystic fibrosis.

As it is well established that an association exists between congenital bilateral absence of the vas deferens (CBAVD) and cystic fibrosis gene mutations, we investigated CFTR(TG)m(T)n polymorphism within a Taiwanese population that exhibits a very low incidence of CF. Sixty-three patients with CBAVD and 86 age-matched normal control subjects were evaluated. Temporal temperature gradient gel electrophoresis was used for CFTR mutational analysis. No major CFTR mutation was found in the patient series. A single prominent CFTR mutation, IVS8-5T, was present; however, (50.8% of 63 cases and 33.3% of 126 alleles), and exhibited a high prevalence of 12 or 13 TG repeats (93.8% of 32 cases and 95.2% of 42 alleles with IVS8-5T). Although these results are similar to those of Japanese CBAVD patients, they are higher than the common frequency (about 21%) found among Caucasian CBAVD patients. The very high percentage (42.9%) of patients with no CFTR mutations is also an ethnic characteristic. We concluded that CBAVD patients from Taiwan, who express a very low incidence of CF, were less affected by CFTR mutations, with the exception of IVS8-5T linked to either 12 or 13 TG repeats, which does exhibit a high prevalence among CBAVD patients tested.

In vitro binding of heavy metals by an edible biopolymer poly(gamma-glutamic acid).

An edible biopolymer poly(gamma-glutamic acid) (gamma-PGA) was evaluated for possible use as an chelating/binding agent in the treatment of metal intoxication in humans. In vitro binding of the toxic heavy metals lead and cadmium as affected by pH, contact time, metal concentration, gamma-PGA dose, and essential metals was carried out in a batch mode. A maximum binding occurred in the pH range 5-7, corresponding to the gastrointestinal pH values except for the stomach. Binding isotherms at pH 5.5 were well described by the heterogeneous models (Freundlich and Toth), while the lead isotherm at pH 2.5 showed a S-type curve, which was fitted as multiple curves with the Langmuir model and a shifted-squared Langmuir model. However, no adsorption occurred for cadmium at pH 2.5. The maximum binding capacities of lead and cadmium at pH 5.5 were 213.58 and 41.85 mg/g, respectively. A curvilinear biphasic Scatchard plot signified a multisite interaction of metals. Binding was extremely rapid with 70-100% of total adsorption being attained in 2 min. Kinetics at low and high metal concentrations obeyed pseudo-first-order and pseudo-second-order models, respectively. The gamma-PGA dose-activity relationship revealed a low dose of gamma-PGA to be more efficient in binding a large amount of metals. Incorporation of Cu, Zn, Fe, Mg, Ca, and K showed only a minor influence on lead binding but significantly reduced the binding of cadmium.

Adsorption of toxic mercury(II) by an extracellular biopolymer poly(gamma-glutamic acid).

Adsorption of mercury(II) by an extracellular biopolymer, poly(gamma-glutamic acid) (gamma-PGA), was studied as a function of pH, temperature, agitation time, ionic strength, light and heavy metal ions. An appreciable adsorption occurred at pH>3 and reached a maximum at pH 6. Isotherms were well predicted by Redlich-Peterson model with a dominating Freundlich behavior, implying the heterogeneous nature of mercury(II) adsorption. The adsorption followed an exothermic and spontaneous process with increased orderliness at solid/solution interface. The adsorption was rapid with 90% being attained within 5 min for a 80 mg/L mercury(II) solution, and the kinetic data were precisely described by pseudo second order model. Ionic strength due to added sodium salts reduced the mercury(II) binding with the coordinating ligands following the order: Cl(-) >SO(4)(2-) >>NO(3)(-). Both light and heavy metal ions decreased mercury(II) binding by gamma-PGA, with calcium(II) ions showing a more pronounced effect than monovalent sodium and potassium ions, while the interfering heavy metal ions followed the order: Cu(2+) >> Cd(2+) > Zn(2+). Distilled water adjusted to pH 2 using hydrochloric acid recovered 98.8% of mercury(II), and gamma-PGA reuse for five cycles of operation showed a loss of only 6.5%. IR spectra of gamma-PGA and Hg(II)-gamma-PGA revealed binding of mercury(II) with carboxylate and amide groups on gamma-PGA.

The effects of benzene exposure on apoptosis in epithelial lung cells: localization by terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling (TUNEL) and the immunocytochemical localization of apoptosis-related gene products.

Although benzene, a well-known human carcinogen, has been shown to induce apoptosis in vitro, no studies have been carried out to confirm and characterize its role in activating apoptosis in vivo. The present study investigated the effects of benzene inhalation on the epithelial cells lining the respiratory tract including bronchioles, terminal bronchioles, respiratory bronchioles and alveoli of male Sprague-Dawley rats. Inhalation of benzene 300 ppm for 7 days induced apoptotic changes in the parenchymal components in the lung that significantly exceeded the events of programmed cell death in normal control tissues. Apoptosis was confirmed by the electrophoretic analysis of internucleosomal DNA fragmentation of benzene-exposed lung tissues, which exhibited 180-200 bp laddering subunits indicative of genomic DNA degradation. Furthermore, semi-quantitative analysis of intracellular localization of terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling TUNEL) showed a significant (p < 0.001) increase in the apoptotic index calculated for bronchiolar 73.5%, terminal bronchiolar (65%), and respiratory bronchiolar 60.8% segmental epithelial components as well as alveolar (55%) epithelia. Analysis of immunohistochemical expression of apoptosis-related gene products also supported the hypothesis that benzene can induce apoptosis in chemosensitive target cells in the lung parenchyma. Quantitative immunhistochemistry showed a statistically significant increase p < 0.001 in the immunoreactive staining index for cytochrome c, Apaf-1 (apoptosis activating factor-1), DNA fragmentation factor, and representative cysteine proteases including caspase-1, caspase-2L, caspase-8 and caspase-9. Thus this is the first study of the respiratory system that demonstrates that benzene inhalation induces lung cell apoptosis as confirmed by DNA electrophoresis, in situ nick end labeling, and the upregulation of apoptosis-related gene products that facilitate caspase-cleaved enzymes which lead to cell degradation via programmed cell death. These responses may represent an important defense mechanism within the parenchymal cells of the respiratory system that reduce mutational hazard and the potential carcinogenic effects of benzene-initiated pathogenesis.

Role of ALDP (ABCD1) and mitochondria in X-linked adrenoleukodystrophy.

Peroxisomal disorders have been associated with malfunction of peroxisomal metabolic pathways, but the pathogenesis of these disorders is largely unknown. X-linked adrenoleukodystrophy (X-ALD) is associated with elevated levels of very-long-chain fatty acids (VLCFA; C(>22:0)) that have been attributed to reduced peroxisomal VLCFA beta-oxidation activity. Previously, our laboratory and others have reported elevated VLCFA levels and reduced peroxisomal VLCFA beta-oxidation in human and mouse X-ALD fibroblasts. In this study, we found normal levels of peroxisomal VLCFA beta-oxidation in tissues from ALD mice with elevated VLCFA levels. Treatment of ALD mice with pharmacological agents resulted in decreased VLCFA levels without a change in VLCFA beta-oxidation activity. These data indicate that ALDP does not determine the rate of VLCFA beta-oxidation and that VLCFA levels are not determined by the rate of VLCFA beta-oxidation. The rate of peroxisomal VLCFA beta-oxidation in human and mouse fibroblasts in vitro is affected by the rate of mitochondrial long-chain fatty acid beta-oxidation. We hypothesize that ALDP facilitates the interaction between peroxisomes and mitochondria, resulting, when ALDP is deficient in X-ALD, in increased VLCFA accumulation despite normal peroxisomal VLCFA beta-oxidation in ALD mouse tissues. In support of this hypothesis, mitochondrial structural abnormalities were observed in adrenal cortical cells of ALD mice.