Hemocompatibility of bioprosthetic heart valve materials respectively based on glutaraldehyde and non-glutaraldehyde treatment / 中国胸心血管外科临床杂志

@#Objective    To study the hemocompatibility of bioprosthetic heart valve materials respectively based on glutaraldehyde and non-glutaraldehyde treatment. Methods    Fresh bovine pericardium was treated with glutaraldehyde or non-glutaraldehyde after adipose tissue was removed. To evaluate the hemocompatibility of the two bioprosthetic heart valve materials, hemolysis test, in vitro fibrinogen adsorption experiment, platelet adhesion experiment, thrombin-antithrombin complex (TAT) test, complement activation assay and ex vivo circulation experiment were performed. Results    The hemolysis test results demonstrated that both of the materials showed hemolytic rates lower than 5%. The results of TAT test and complement activation assay showed no statistical differences among the two materials and the blank control group. Compared to the bioprosthetic heart valve materials with glutaraldehyde-based treatment, the materials with non-glutaraldehyde-based treatment showed significantly decreased fibrinogen adsorption, platelet adhesion and thrombosis. Conclusion    Compared to the bioprosthetic heart valve materials with glutaraldehyde-based treatment, the materials with non-glutaraldehyde-based treatment show better hemocompatibility.

Current Overview for Chemical Disinfection of Dental Impressions and Models based on its Criteria of Usage: A Microbiological Study

Objectives: The aims of this study were to compare the efficacy of two proven chemical disinfectants, glutaraldehyde and povidone iodine on dental impression and models by determining the reduction in the microbial load, and to compare changes in the physical properties of the models after adding the disinfectants. Materials and Methods: Irreversible hydrocolloid upper impressions of 90 patients were made and divided into 3 groups of 30 samples each; Group A––Control group; Impressions were run under clean tap water before pouring the model. Group B––2% Glutaraldehyde sprayed on the impression and left in situ for 10 min before pouring the model. Group C –10 ml of (5%) povidone iodine incorporated into the gypsum before pouring the model. Models from all three groups were subjected to microbiological assessment at three different time intervals, T0––24 h, T1––1 month and T2––3 months of storage by comparing the colony forming units (CFUs) of bacteria and fungi. The compressive strength of 5 models from each group was also analyzed in Newton’s/mm2. Results: 2% Glutaraldehyde proved more effective than povidone iodine after 24 h of storage (T1), however at the end of 1 month (T1) and 3 months (T2) the Povidone group showed the maximum disinfection. Both the disinfectants caused a reduction in the compressive strength of the model with the povidone iodine group showing the maximum reduction. Conclusion: Although povidone iodine was the most effective disinfectant after 3 months, it showed a significant reduction in the compressive strength and caused discoloration of the model. 2% Glutaraldehyde proved to be the choice of disinfectant with minimal adverse effects

Study on preparation of poly-Carboxyhemoglobin by glutaraldehyde crosslinking / 中国输血杂志

【Objective】 To investigate the preparation conditions of hemoglobin-based oxygen carrier (HBOC) at room temperature without oxygen isolation and the quality of poly-COHb. 【Methods】 Using human cord blood hemoglobin as raw material and glutaraldehyde as crosslinking agent, the experimental group selected hemoglobin concentration, glutaraldehyde to COHb molar ratio, reaction time and reaction temperature to do four factors and three levels of orthogonal test (n=3), to determine the best matching conditions and prepare three batches of poly-COHb, continuously.In the control, 3 batches of poly-Hb were prepared under low temperature and oxygen isolation.The contents of superlarge molecules, degree of polymerization, average molecular weight, methemoglobin and P50 of crosslinked products were compared between the two groups. 【Results】 The optimal matching conditions of poly-COHb were as follows: [Hb] 70g/L, the molar ratio of glutaraldehyde to COHb was 11∶1, the reaction time was 60 min, and the reaction temperature was 25℃.Comparison of poly-COHb and poly-Hb: The superlarge molecular content (%) was 0.67±0.51 vs 0.60±0.01 (P>0.05); degree of polymerization (%) and average molecular weight (kD) were 84.25±0.99 vs 54.16±5.12, and 235.27±13.50 vs 97.62±6.57, respectively.(P<0.05); methemohemoglobin ratio (%) was 2.40±0.66 vs 2.47±0.46 (P>0.05); P50 (mmHg) was 6.37±0.30 vs 14.20±1.09 (P<0.05). 【Conclusion】 Poly-COHb can be prepared at room temperature without oxygen isolation.Compared with poly-Hb, poly-COHb prepared under the experimental conditions can improve the polymerization degree and average molecular weight, and greatly reduce the difficulty of preparation.

Preparation of a novel double polymerized of red blood cell substitute and preliminary observation of its curative effect / 中国输血杂志

【Objective】 To study the red blood cell substitute preparation method of glutaraldehyde(GDA) and Bis(3, 5-dibromosalicyl) fumarate(DBBF) double polymerized, and also observe its curative effect. 【Methods】 The affecting factors of the crosslink of DBBF and human placental hemoglobin(Hb) were selected, including solution pH, inositol hexaphosphoric acid concentration, and molar ratios of DBBF/Hb. The changes of P50, Hill Co and methemoglobin(MetHb) content during the preparation process were studied and the molar ratio of GDA to DBBF-Hb were determined. The final product was obtained through the steps of ultrafiltration, filtration, and deoxygenation, etc., and the final product was subjected to a study on the curative effect of anti-hemorrhagic shock in rats. 【Results】 Under the condition of pH 8.0, the concentration of inositol hexaphosphoric acid was 10mM/L, the molar ratio of DBBF/hemoglobin was 6∶1, the content of dimer was(22.67±3.28)%, the content of tetramer was (74.64±7.05)%, and its P50 was (25.25±2.31) mmHg. As the molar ratio of DBBF/Hb increased, P50 and MetHb content would gradually increase, while the Hill Co will gradually decrease. The molar ratio of GDA and DBBF-Hb was 7∶1, the content of dimer was (8.23±0.79)%, the content of tetramer was (27.87±3.63)%, the content of super-macromolecule was (1.05±0.31)%. As the molar ratio of GDA and DBBF/Hb increased, MetHb content would increase, while the P50 and Hill Co would gradually decrease. The 24h survival rate of the product in rats with hemorrhagic shock was 83.33%(10/12), which was significantly higher than that in the negative control group[41.67%(5/12)], while similar with the positive control group [91.67%(11/12)]. 【Conclusion】 The red blood cell substitutes with GDA and DBBF double polymerized can effectively reduce the dimer content, which is more conducive to industrial production, and has a positive effect on the treatment of hemorrhagic shock.

Effect of HSRP1 oxygen-carrying solution on early perfusion in rabbits with controlled severe hemorrhagic anemia / 中国输血杂志

【Objective】 To observe the effect of glutaraldehyde polymerized bovine hemoglobin injection (code: HSRP1) oxygen-carrying fluid on early perfusion of severe hemorrhagic anemia in rabbits. 【Methods】 The rabbit model of controlled severe hemorrhagic anemia was established. Twelve modeled rabbits were divided into glutaraldehyde polymerized bovine hemoglobin injection (code: HSRP1) group and sodium lactate ringer′s injection (LR) group, with 6 rabbits in each group(half male and half female). HSPR1 group and LR group were treated with HSRP1 and LR, respectively. The survival rate of experimental rabbits was observed, and the indexes of hemodynamics, venous blood gas, plasma hemoglobin, base surplus, lactic acid and bicarbonate were measured before and after blood loss, as well as each point within 24 h after infusion. 【Results】 The survival rate of HSRP1 group was significantly different from that of LR group (P<0.05); After exsanguination, the mean arterial pressure of each group was significantly different from that before exsanguination (P<0.05), but there was no significant difference between HSPR1 group and LR group after infusion; In the second stage of perfusion, the blood lactate concentration and base excess in the HSRP1 group were significantly different from those in the LR group at each time point (P<0.05), at 2 h after perfusion, the respiratory rate started to differ significantly from that of the LR group (P<0.05), heart rate was significantly different from LR group at 4 h after perfusion(P<0.05); There were no significant differences between HSRP1 group and LR group in plasma venous oxygen partial pressure, venous oxygen saturation and plasma hemoglobin at all time points. 【Conclusion】 HSPR1 is used for severe traumatic hemorrhagic shock in rabbits, and can improve the survival rate of experimental rabbits by providing oxygen to hypoxic tissues and correcting anaerobic metabolism. As a new oxygen-carrying fluid, HSPR1 can correct the oxygen supply balance of patients with severe hemorrhagicanemia in early stage.

Effects of different crosslinking treatments on the properties of decellularized small intestinal submucosa porous scaffolds / 北京大学学报(医学版)

OBJECTIVE@#To compare the effects of three different crosslinkers on the biocompatibility, physical and chemical properties of decellularized small intestinal submucosa (SIS) porous scaffolds.@*METHODS@#The SIS porous scaffolds were prepared by freeze-drying method and randomly divided into three groups, then crosslinked by glutaraldehyde (GA), 1-ethyl-3-(3-dimethylaminopropyl) carbodi-imide (EDC) and procyanidine (PA) respectively. To evaluate the physicochemical property of each sample in different groups, the following experiments were conducted. Macroscopic morphologies were observed and recorded. Microscopic morphologies of the scaffolds were observed using field emission scanning electron microscope (FESEM) and representative images were selected. Computer software (ImageJ) was used to calculate the pore size and porosity. The degree of crosslinking was determined by ninhydrin experiment. Collagenase degradation experiment was performed to assess the resistance of SIS scaffolds to enzyme degradation. To evaluate the mechanical properties, universal mechanical testing machine was used to determine the stress-strain curve and compression strength was calculated. Human bone marrow mesenchymal cells (hBMSCs) were cultured on the scaffolds after which cytotoxicity and cell proliferation were assessed.@*RESULTS@#All the scaffolds remained intact after different crosslinking treatments. The FESEM images showed uniformed interconnected micro structures of scaffolds in different groups. The pore size of EDC group[(161.90±13.44) μm] was significantly higher than GA group [(149.50±14.65) μm] and PA group[(140.10±12.06) μm] (P < 0.05). The porosity of PA group (79.62%±1.14%) was significantly lower than EDC group (85.11%±1.71%) and GA group (84.83%±1.89%) (P < 0.05). PA group showed the highest degree of crosslinking whereas the lowest swelling ratio. There was a significant difference in the swelling ratio of the three groups (P < 0.05). Regarding to the collagenase degradation experiment, the scaffolds in PA group showed a significantly lower weight loss rate than the other groups after 7 days degradation. The weight loss rates of GA group were significantly higher than those of the other groups on day 15, whereas the PA group had the lowest rate after 10 days and 15 days degradation. PA group showed better mechanical properties than the other two groups. More living cells could be seen in PA and EDC groups after live/dead cell staining. Additionally, the proliferation rate of hBMCSs was faster in PA and EDC groups than in GA group.@*CONCLUSION@#The scaffolds gained satisfying degree of crosslinking after three different crosslinking treatments. The samples after PA and EDC treatment had better physicochemical properties and biocompatibility compared with GA treatment. Crosslinking can be used as a promising and applicable method in the modification of SIS scaffolds.

Experimental study of adventitial collagen cross-linking by glutaraldehyde reducing intimal hyperplasia of vein graft / 中华胸心血管外科杂志

Objective:To evaluate the validity of adventitial collagen cross-linking by glutaraldehyde(GA) to reduce intimal hyperplasia of vein graft in a rabbit carotid artery bypass graft model.Methods:Harvesting 36 segments of the external jugular vein and 6 segments of the internal carotid artery with 3 cm length from the New Zealand white rabbits. The veins were randomly divided into 6 groups and underwent adventitial collagen cross-linking by 0.3% glutaraldehyde for 0 min, 1 min, 2 min, 3 min, 4 min, and 5 min, respectively. All vessel segments were subjected to biomechanical tests and pathological tests. Carotid artery bypass graft models were established in 24 New Zealand white rabbits including crosslinked group(n=12) and non-crosslinked group(n=12). The vein grafts were obtained for pathological examination 4 weeks after models feeding, and the intimal hyperplasia of vein graft was evaluated.Results:Adventitial cross-linking increased fiber density of adventitia significantly, and increased the stiffness of the veins as the time of cross-linking increased. And in the high strain region(strain ratio 1.4-1.8), the mechanical curve of veins receiving 3min cross-linking was similar to that of the carotid artery. The patent rate of the vein grafts of rabbit models was 100% after 4 weeks. Comparing with non-crosslinked group, the intimal and medial thickness of vein grafts in crosslinked group were reduced remarkably[(78.83±9.02)μm vs.(140.19±19.90)μm, (43.75±5.05)μm vs.(58.35 ± 8.61) μm, P<0.01). Conclusion:Adventitial collagen cross-linking by GA can enhance the mechanical strength of the jugular vein, and reduce the intimal hyperplasia of the jugular vein grafts in rabbit models.

Infection in Minimal Access Surgery and Glutaraldehyde

Background: With increasing use of MAS for various surgicalprocedures, the occurrence of port site infection and port sitetuberculosis is seen more often as postoperative complicationin Bangladesh. Most of the cases present as non-healing portsite wounds. The infection has been attributed to impropersterilization of laparoscopy instruments. There is concern aboutthe effectiveness of the high-level disinfection of reusablelaparoscopic instruments by immersion in 2% glutaraldehyde(GTA).Objective: To evaluate the infection and efficacy ofglutaraldehyde in MAS.Materials and Methods: This is a retrospective, observationalstudy carried out during the period of October 2005 to March2016. Study populations were all the patients underwentvarious minimal access surgical procedures by our team duringthis period. Surgeries were performed by Storz standardlaparoscopy set. All instruments were immersed in 2% GTA for15-20 minutes before each use.Results: Among all the patients (3720), 206 had port siteinfection which is 5.53%. Seventeen cases were diagnosed asport site tuberculosis which is about .45%. Most of them werewithin 30-40 years of age groups. Patients presented with portsite cellulitis, abscess and discharging sinus. All tuberculouscases were confirmed by biopsy. Tuberculous patientsresponded to anti-tubercular therapy. Non- specific infectionsresponded to dressing and antibiotics.Conclusion: Port site infection is common but tuberculosis isnot as common as non- specific infection. Both aretroublesome for the patients and surgeons. Proper sterilizationof instruments is the key. Use of 2% GTA is not cent percenteffective against tuberculosis.

Comparison of disinfection effects of three disinfectants on gastroscope:a meta analysis / 中华消化内镜杂志

Objective To evaluate the disinfect effects of glutaraldehyde, ortho-phthalaldehyde ( OPA ) and peracetic acid on gastroscopy disinfection. Methods Relevant literature from PubMed, Cochrane Library, web of science, Embase, CNKI, CBM, VIP were retrieved to collect the randomized controlled trials on disinfection by glutaraldehyde, OPA and peracetic acid on gastroscope. Literature was selected according to the inclusion and exclusion criteria. The RevMan 5. 3. 4. 0 statistic software was used to extract data and a meta-analysis was performed. Results A total of 18 RCT were included. There were significant differences in the disinfect effects between the OPA group and the glutaraldehyde group ( OR=2. 02, 95％CI:1. 88-1. 27, P<0. 00001), and between the peracetic acid group and the glutaraldehyde group ( OR = 2. 79, 95％CI:1. 52-5. 11, P = 0. 0009 ) . There were no significant differences in the disinfection effect between the OPA group and peracetic acid group ( OR=1. 30,95％CI:0. 62-2. 73, P=0. 49) . Conclusion The disinfect effects of OPA and peracetic acid are similar, which are superior to glutaraldehyde. Compared with OPA and glutaraldehyde, peracetic acid is a better choice considering its good disinfect effect and low cost.

Glutaraldehyde test for the rapid diagnosis of pulmonary and extra-pulmonary tuberculosis in an area with high tuberculosis incidence

BACKGROUND Tuberculosis (TB) remains one of the leading causes of morbidity and mortality worldwide. The primary method for controlling TB is the rapid and accurate identification of infected individuals. Immune response exploitation represents one of the main methods used for early TB diagnosis; however, few studies have reported that whole blood originating from TB-infected patients gels faster in the presence of aldehyde than blood originating from healthy subjects, which is the focus of the current study. OBJECTIVES The study objectives are to determine the diagnostic value of a glutaraldehyde test (GT) in pulmonary tuberculosis (PTB) and extra-pulmonary tuberculosis (EPTB) and to assess its performance compared with light-emitting diode fluorescence microscopy (LED-FM). MATERIALS AND METHODS This study included 272 specimens (176 suspected PTB specimens and 96 suspected EPTB specimens). Of the 272 patients, 98 patients had TB infection confirmed by culture (64 PTB cases and 34 EPTB cases), and 174 patients had no TB infection. The gold standard technique (culture) was used as reference to verify the GT's performance. RESULTS The GT showed a high sensitivity (96.9%) and specificity (82.1%) for PTB with a good positive predictive value (PPV = 75.6%) and negative predictive value (NPV = 97.9%). For EPTB, the GT showed a sensitivity of 91.2% and a specificity of 77.4%, with PPV = 68.9% and NPV = 94.1%. LED-FM had lower sensitivities for PTB (65.6%) and EPTB (42.1%) and an excellent specificity of 100%, with PPV = 100% and NPV = 100%. CONCLUSION We concluded that GT is rapid, easy, simple and cost-effective and does not require qualified personnel with a specific background or sophisticated equipment like molecular biology or mycobacterium-specific genotyping techniques. These qualities make the GT attractive for use in low- and high-income countries in addition to other conventional methods, particularly culture, which continues to be the gold standard.

Role of Glutaraldehyde in Imparting Stability to Immobilized β-Galactosidase Systems

ABSTRACT This review article highlights the role of glutaraldehyde as a matrix activator/stabilizer in imparting higher operational and thermal stability to β-galactosidase (βG) for biotechnological applications. Glutaraldehyde has been used extensively as a crosslinking agent as well as for functionalization of matrices to immobilize β-galactosidase. Immobilized β-galactosidase systems (IβGS) obtained as a result of glutaraldehyde treatment has been employed to hydrolyze whey and milk lactose in batch reactors, continuous packed-bed and fluidized bed reactors under various operational conditions. Moreover, these IβGS have also been utilized for the production of galactooligosaccharides in food, dairy and fermentation industries. It was observed that glutaraldehyde provided remarkable stability to immobilize βG against various physical/chemical denaturants, thus enhancing thermal/operational stability and rendering it more suitable for repeated utilization in industrial scale operations.

Bactericidal mechanism of electrolyzed oxidizing water against Pseudomonas aeruginosa / 中国感染控制杂志

Objective To investigate the bactericidal mechanism of electrolyzed oxidizing water (EOW) against Pseudomona aeruginosa (P.aeruginosa).Methods Bactericidal mechanism of EOW against P.aeruginosa was studied through intracellular protein leakage,nucleic acid,and cell membrane calcium ion permeability,2 ％ glutaraldehyde was used as positive control group,and normal saline (NS) was used as negative control group.Results The killing rates of EOW and 2％ glutaraldehyde to P.aeruginosa were both＞99.99％ with 30-second contact time,and 100.00％ with 60-second contact time.After 60-second contact with EOW,NS,and 2％ glutaraldehyde,the protein leakage of P.aeruginosa detected by bicinchoninic acid (BCA) were (96.00 ± 7.42),(94.15 ± 7.49),and (216.97 ± 10.35)μg/mL,respectively,difference was significant(F =613.20,P＜0.01),2％ glutaraldehyde group was higher than EOW group and NS group;protein leakage did not change with the increase of contact time(all P＞0.05).Electrophoretogram of random amplified polymorphic DNA showed high intensity dense band between 500-1000 Kb in EOW group and NS group,while 2％ glutaraldehyde group was without amplified bands.The fluorescence intensity of calcium ion of EOW group and 2％ glutaraldehyde group were both lower than that of NS group.Conclusion Bactericidal mechanism of EOW may be due to the damage of membrane permeability of P.aeruginosa,which causes Ca2+ leakage,but fails to cause protein leakage,the damage to nucleic acid is not obvious,DNA may not be a bactericidal target of EOW.

Gelatin-based microspheres crosslinked with glutaraldehyde and rutin oriented to cosmetics

ABSTRACT Glutaraldehyde (GTA) has been extensively used as a gelatin crosslinking agent, however, new natural ones have been suggested as more biocompatible. Polyphenols are possible candidates and the flavonols, such as rutin (RUT), also exhibit potential synergism with sunscreens and antioxidant agents used in cosmetics. In this work, gelatin microspheres (M0) were obtained and crosslinked with GTA 10 mM (MG) or RUT 10 mM (MR), dissolved in acetone:NaOH 0,01M (70:30 v/v). MG exhibited crosslinking extent of 54.4%. Gelatin, M0, MG and MR did not elicit any signs of skin damage, regarding the formation of erythema, the barrier function disruption and negative interference in the stratum corneum hydration. Oily dispersions containing M0, MG or MR, isolated or combined with benzophenone-3 or octyl methoxycinnamate, suggested that the microspheres, at a 5.0% w/w, had no additional chemical or physical photoprotective effect in vitro. Crosslinking with RUT had occurred, but in a lower degree than GTA. Microspheres had not improved sun protection parameters, although, non-treated gelatin interfered positively with the SPF for both UV filters. The in vivo studies demonstrated that these materials had very good skin compatibility.

Bioadhesive HPMC Gel Containing Gelatin Nanoparticles for Intravaginal Delivery of Tenofovir.

The aim of the present study is to formulate tenofovir loaded gelatin nanoparticles by two step desolvation method for targeted release of drug by varying the concentration of polymer and cross-linking agent. Entrapment efficiency for all the formulations was found to be within 67.32 ± 1.24 % to 92.11 ± 1.13 %. Average particle size of different tenofovir loaded gelatin nanoparticle formulations was found within the range of 294.9 - 445.3 nm. In-vitro drug release study for glutaraldehyde cross linked gelatin nanoparticles were found between 67.09 % ± 1.423 – 82.41 % ± 1.874 after 8 h of dissolution. F5 (850 mg gelatin, 0.2 ml glutaraldehyde) was considered as the best formulation based on the entrapment efficiency and drug release from nanoparticle core. Kinetics study was performed for all the formulations and best fit model for drug release was determined depending on R squared values. HPMC K15M was used as a bioadhesive polymer as well as a gelling agent. Three different gel formulations were prepared by varying concentration of HPMC K15M and incorporated with the best formulation, F5. Membrane permeation and bio-adhesion study revealed F5B gel (5% HPMC K15M) as an optimum formulation with suitable bioadhesive strength and membrane permeability.

Evaluation of Shear Bond Strength of Two Dentin Bonding Agents with Two Desensitizers (An In-Vitro Study).

Background: The esthetic quality of a restoration may be as important to the mental health of the patient as the biological and technical qualities of the restoration are to his physical or dental health. In Conservative Dentistry; to mimic, repair and reconstruct the natural tooth structure for the long term, would be based on the use of a restorative material retained only by an adhesive system, whether in load bearing or non-load bearing environments. To achieve high strength, bonds between tooth structure and restorative materials have been a long term goal of dental profession. Aim: The aim of this in vitro study was to compare the shear bond strength of two different dentin bonding agents with two different desensitizers. Materials and Methods: Eighty molars were taken, which were ground to expose dentin. The teeth were divided into two major groups. Each major group was subdivided into four subgroups of 10 samples each. Groups Ia and IIa were treated as dry bonding groups, groups Ib and IIb were treated as moist bonding groups, group Ic and IIc were rewetted with Gluma desensitizer, and groups Id and IId were rewetted with Systemp® desensitizer. Major group I was treated with Gluma comfort bond and Charisma. Major group II was treated with 3M ESPE Adper™ Single Bond 2 and 3M ESPE Filtek™ Z250. The samples were thermocycled and shear bond test was performed using Instron machine. The data was analyzed using one-way analysis of variance and Tukey’s significant different test. Results: The results revealed that the specimens rewetted with Gluma desensitizer showed the higher shear bond strength compared to all other groups, irrespective of the bonding agent or composite resin used. Conclusion: It can be concluded that the moist or rewetting technique could preserve the micro-morphological integrity of the collagen resulting in the optimum penetration of adhesive resin into the demineralized layer, thus, giving higher bond strength.

Evaluation Of Shear Bond Strength Of Two Dentin Bonding Agents With Two Desensitizers – An In-Vitro Study.

Background & Objective: The aesthetic quality of a restoration may be as important to the mental health of the patient as the biological and technical qualities of the restoration are to his physical or dental health. In Conservative Dentistry; to mimic, repair and reconstruct the natural tooth structure for the long term, would be based on the use of a restorative material retained only by an adhesive system, whether in load bearing or non-load bearing environments. To achieve high strength, bonds between tooth structure and restorative materials have been a long term goal of dental profession. Objective is to compare the shear bond strength of two different dentin bonding agents with two different desensitizers. Methodology: Eighty molars were taken, which were ground to expose dentin. The teeth were divided into two major groups. Each major group was subdivided into four subgroups of 10 samples each. Groups Ia and IIa were treated as dry bonding groups, groups Ib and IIb were treated as moist bonding groups, group Ic and IIc were rewetted with Gluma desensitizer, and groups Id and IId were rewetted with Systemp® desensitizer. Major group I was treated with Gluma comfort bond and Charisma. Major group II was treated with 3M ESPE Adper™ Single Bond 2 and 3M ESPE Filtek™ Z250. The samples were thermocycled and shear bond test was performed using Instron machine. The data was analyzed using one-way analysis of variance and Tukey’s significant different test. Results: The results revealed that the specimens rewetted with Gluma desensitizer showed the higher shear bond strength compared to all other groups, irrespective of the bonding agent or composite resin used. Conclusion: It can be concluded that the moist or rewetting technique could preserve the micromorphological integrity of the collagen resulting in the optimum penetration of adhesive resin into the demineralized layer, thus, giving higher bond strength.

Toxicity of crude and detoxified Tityus serrulatus venom in anti-venom-producing sheep

Specific anti-venom used to treat scorpion envenomation is usually obtained from horses after hyperimmunization with crude scorpion venom. However, immunized animals often become ill because of the toxic effects of the immunogens used. This study was conducted to evaluate the toxic and immunogenic activities of crude and detoxified Tityus serrulatus (Ts) venom in sheep during the production of anti-scorpionic anti-venom. Sheep were categorized into three groups: G1, control, immunized with buffer only; G2, immunized with crude Ts venom; and G3, immunized with glutaraldehyde-detoxified Ts venom. All animals were subjected to clinical exams and supplementary tests. G2 sheep showed mild clinical changes, but the other groups tolerated the immunization program well. Specific antibodies generated in animals immunized with either Ts crude venom or glutaraldehyde-detoxified Ts venom recognized the crude Ts venom in both assays. To evaluate the lethality neutralization potential of the produced sera, individual serum samples were pre-incubated with Ts crude venom, then subcutaneously injected into mice. Efficient immune protection of 56.3% and 43.8% against Ts crude venom was observed in G2 and G3, respectively. Overall, the results of this study support the use of sheep and glutaraldehyde-detoxified Ts venom for alternative production of specific anti-venom.

Preparation and characterization of microspheres for controlled release of anti HIV drug.

A series of blend microspheres were developed from gelatin and hydroxypropyl cellulose (HPC) by emulsion crosslinking method employing glutaraldehyde (GA) as a crosslinker. Valganociclovir hydrochloride (VHCL), an anti HIV drug, was loaded in to these microspheres via insitu method. These microspheres were characterized by Fourier transform infrared spectroscopy (FTIR), to confirm the formation of crosslinking and absence of chemical interactions between drug, polymer and crosslinking agent. Further the microspheres were characterized by scanning electron microscopy to study the surface morphology of the microspheres and observed that the microspheres have smooth surface with spherical structure and no phase separation. The microspheres with the average particle sizes ranging from 614.5μm to 693.4μm were obtained. X-ray diffraction (X-RD) studies were performed to understand the crystalline nature of drug and its uniform distribution into blend microspheres. An in vitro release study was performed in phosphate buffer solution (pH-7.4) at 370C. The release rates were fitted to an emperical equation to understand the diffusion parameters, which indicate non-Fickian or anomalous trend release of VHCL. Further the results indicated that the release of drug was found for more than 12 h.

The Influence of Glutaraldehyde Concentration on Electron Microscopic Multiple Immunostaining

The present study was aimed to evaluate the influence of glutaraldehyde (GA) concentration on multiple electron microscopic (EM) immunostaining using pre-embedding peroxidase and post-embedding immunogold method. Influence of various concentrations of GA included in the fixative on immuoreactivity was assessed in the multiple immunostaining using antisera against anti-transient receptor potential vanilloid 1 (TRPV1) for peroxidase staining and anti-GABA for immunogold labeling in the rat trigeminal caudal nucleus. Anti-TRPV1 antiserum had specificity in pre-embedding peroxidase staining when tissues were fixed with fixative containing paraformaldehyde (PFA) alone. Immunoreactivity for TRPV1 was specific in tissues fixed with fixative containing 0.5% GA at both perfusion and postfixation steps, though the immunoreactivity was weaker than in tissues fixed with fixative containing PFA alone. Tissues fixed with fixative containing 0.5% GA at the perfusion and postfixation steps showed specific immunogold staining for GABA. The results of the present study indicate that GA concentration is critical for immunoreactivity to antigens such as TRPV1 and GABA. This study also suggests that the appropriate GA concentration is 0.5% for multiple immunostaining with peroxidase labeling for TRPV1 and immunogold labeling for GABA.

COMPARATIVE STUDY ON ORTHO-PHTHALALDEHYDE AND GLUTARALDEHYDE FOR DISINFECTION BRONCHOSCOPY / 现代医院

Objective Comparative study of the disinfection expense , turnover rate and the effect on health of ortho-phthalaldehyde and glutaraldehyde used for disinfection of bronchofiberscope , to provide the basis of the promoted application of domestic ortho -phthalaldehyde .Methods Based in turnover time of each bronchofiber-scope, the maxminal disinfection expense in month , the maxminal number of bronchofiberscope in month and the maxminal net value were compared with medical revenue in month .Two different disinfections are calculated .Ques-tionnaires about the effects were sent to twenty workers from the supply room involved in using two different disinfec -tion liquid, and the results were analyzed .Results The disinfection expenses of ortho -phthalaldehyde were higher than that of glutaraldehyde , but bronchofiberscope turnover rate increased by 50%, while medical net revenue in-creased by 40%.According to the questionnaires , the respiratory and conjunctival irritation of the workers were mi-nor, and the symptom of any skin irritation did not appear .Conclusion Although the expense increased , ortho-phthalaldehyde obviously improved the bronchofiberscope turnover rate and medical net revenue ,reduced the staff oc-cupational exposure and equipment residual effects on patients .Thus, ortho-phthalaldehyde is an efficient disinfect-ant that is worthy of being promoted in clinical practice .