Humans ; Hydrofluoric Acid ; Occupational Exposure ; prevention & control ; Protective Devices

Background Increase in ophthalmic optical medical instruments and microsurgical applications leads to retinal photochemical damage and other problems delivery of a variety of devices,so the in-depth study and understanding of its pathogenesis after retina light damage can provide a reference for the clinical treatment of related diseases.Objective This study was to investigate the therapeutic effect and relative mechanism of erythropoietin (EPO) on mouse retina photic injury by studying the expression of matrix metalloproteinases-2 (MMP-2)and MMP-9.Methods Fifty-two SPF BALB/c mice were randomized into normal control group,simple light-induced group and EPO pretreatment group by balloting method.The mice of simple light-induced group and EPO pretreatment group were continuously irradiated with 6000 lx diffuse light for 4 hours in a home-made box to establish the models of light-induced damage;while recombinant human EPO (rhEPO)of 5000 U/kg was intraperitoneally injected prior to the light exposure in the EPO pretreatment group.The expressions of MMP-2 and MMP-9 were examined at 6,12,36,72,96 hours and 7 days following light-exposure by immunohistochemistry.Results Edema and structural disorder of RPE cells appeared inthe simple light-induced group after light-exposure and aggravated with lapse of light-exposure time,but no similar change was seen until 7 days in the EPO pretreatment group.The immunohistochemistry findings showed that the expression of MMP-2(A value)in RPE cells was less in the normal mice.However,a large quantity of positive cells appeared in RPE layer 36 hours after light-exposure.Compared with the simple light-induced group,the positive expression of MMP-2 protein in EPO pretreatment group was significantly decreased,showing statistically significant differences among these three groups and different time points (Fgroup =3.68,P =0 04; Ftime =9.13,P=0.00).There was hardly any MMP-9 expression in the retina of the normal mice.In simple light-induced group,a few of positive cells appeared in RPE layer 6 hours after light-exposure and reached its peak 12 hours following light-exposure.The gradually down-regulation of MMP-9 expression happened 96 hours later following light-irradiation.The expression tendency of MMP-9 in EPO pretreatment group was similar to the simple light-induced group.Significant differences in expressions of MMP-9 were found among different groups and time points (Fgroup=3.61,P =0.04;Ftime =16.91,P=0.00).Conclusions MMP-2 and MMP-9 may be involved in the mechanism of retina photic injury by down-regulating the expression of MMP-2 and MMP-9 in RPE cells.

Objective To assess the value of rigid wall and outer coarse signs in 64-slice CT for pre-operation stages of colorectal carcinoma. Methods One hundred and twenty-three colorectal carcinoma patients underwent 64-slice CT;then rigid wall and out coarse signs were evaluated respectively. The tumors were grouped according to the postoperative pathologic infiltrative depth. Two signs of the neighboring infiltrative depth groups were compared and analyzed, so as the relativity between two signs and tumor infiltrative depth. Results Among all 123 patients, 7 were Tis, 6 were T1, 14 were T2a, 16 were T2b, 75 were T3 (including 22 infiltrate to chorion and 53 infiltrate through chorion) and 5 were T4. According to the pathologic infiltrative depth, the patients were grouped into GroupⅠ: Tis+T1;GroupⅡ: T2a;Group Ⅲ: T2b;Group Ⅳ: T3a;Group Ⅴ: T3b+T4. Significant difference of the incidence of rigid wall was found between GroupⅠand Ⅱ (P=0.013), while of outer coarse between Group Ⅱ and Ⅲ (P=0.004). Coefficient correlation of rigid wall, outer coarse and the infiltrative depth of the tumor were detected (r=0.673, r=0.528, respectively, both P＜0.001), also between the two signs (r=0.725, P＜0.001). To predict the tumor of and above T1 with rigid wall and tumor of and above T3a with outer coarse, the sensitivity, specificity and accuracy was 92.30% and 79.31%, 89.09% and 69.44%, 89.43% and 76.42%, respectively. Conclusion The sign of rigid wall is valuable to distinguish the pathological changes in the tumor of and above T1, while outer coarse is better to distinguish the pathological changes of and above T2a, but not good at distinguishing tumors of T2b and T3 or above. Rigid wall and outer coarse are both in positive correlation with the infiltrative depth of the tumor, and each has different values. Combination of the two signs may be helpful to raise the accuracy for pre-operation staging of colorectal carcinoma.

Objective To explore the diagnostic value of thin image and multiplanar reconstruction (MPR) for preoperative T staging on different regions and various pathological staging of colorectal cancer. Methods A total of 163 colorectal cancer patients underwent 64-slice CT examination, then cross section image with thickness of 5 mm (5 mm interval) and 0.5 mm (0.4 mm interval) were reconstructed. The lesions were evaluated and T staged with 5 mm, 0.5 mm and MPR image, respectively. Patients were divided according to the region of lesions: groupⅠ: the anterior wall of lower rectal or near dentate line; groupⅡ: the posterior or lateral wall of lower rectal; group Ⅲ: upper middle rectal or clone. Patients in group Ⅲ were divided into 4 subgroups according to postoperative pathological staging: group A: Tis and T1; group B: T2 (B1: T2a; B2: T2b); group C: T3; group D: T4. The accurate diagnostic rates of different regions, different imaging techniques and different pathological staging were analyzed compared with postoperative pathological results. Results CT accurate T staging diagnostic rate for group Ⅰ, Ⅱ, Ⅲ was 44.44%, 61.54% and 66.67% respectively with 5 mm; 51.85%, 61.54% and 69.92% respectively with 0.5 mm; 51.85%, 76.92% and 78.86% with MPR. There was significant difference of CT accurate diagnostic rates only between group Ⅰ and group Ⅲ (5 mm P=0.031, MPR P=0.004). MRP was better then 5 mm and 0.5 mm only in group Ⅲ (P=0.008, P=0.019). The sensibility of diagnostic T staging of A, B, C and D subgroup in group Ⅲ was as follows: 53.85%, 30.00%(B1: 57.14%, B2: 6.25%), 84.00% and 60.00% with 5 mm; 76.92%, 33.33%(B1: 76.92%, B2: 18.75%),84.00% and 60.00% with 0.5 mm; 92.31%, 53.33%(B1: 78.57%, B2: 31.25%), 86.67% and 80.00% with MPR. CT accurate T staging diagnostic rate of subgroup B2 was significantly lower than those of other groups, and most of the errors were over valuated. Conclusion CT has good sensitivity, specificity and accuracy for diagnostic T staging for early colorectal cancer. MPR can raise the accurate diagnostic rate of upper middle rectal and colon tumor. CT diagnostic value for T staging of lesions at the anterior wall of lower rectal or near dentate line tumor is limited, and the primary cause is over diagnosis of T2b lesions.

Objective To assess the influence of concentrations of sucrose on Streptococcus tautens (S. mutans) gbpC expression. Methods Total RNA was extracted from S. mutans after cultured in 0.5%, 1.0%, 5.0% sucrose and then reversely transcripted to cDNA. By TaqMan RT-RCR technique, we checked gbpC expression. Results Compared with 0.5% sucrose, 1.0% sucrose significantly upregulated gbpC expression(P<0.05); gbpC expression of more-adherent S. mutans strains was higher than that of less-adherent strains, Conclusion The upregulation of gbpC expression by sucrose may be one of the mechanisms underlying the increased adherence; There might be some correlation between gbpC expression andS. mutans adherence.

In this paper, a colorimetric method with high sensitivity, reproducibility and low cost for determining glutamate decarboxylase (GAD) activity was developed based on Berthelot reaction. The optimum substrate system is 0.2 mol/L MacIlvaine buffer pH4.7, containing 0.1 mmol/L pyridoxal phosphate (PLP) and 10 mmol/L L-monosodium glutamate (L-MSG). The reaction mixture consisted of 200 ?L substrate solution and 1～100 ?L enzyme preparation from lactic acid bacteria and was incubated at 30℃. The enzymatic reaction was terminated by immersion in ice-water and addition of 200 ?L 0.2 mol/L sodium borate buffer, pH9.0, then 1 mL 6% phenol solution and 400 ?L sodium hypochloride were added. Color development was carried out in boiling water for 10 min then immediately put in ice-water bath for 20 min. The optical density is read at 630 nm. ?-aminobutyric acid (GABA) produced was calculated using the standard curve. Applications of the method in GAD studies were discussed.

AIM:To evaluate the percentage of cutting fluctuations of central corneal thickness (CCT) intraoperative used low concentration (0.02%) mitomycin C (MMC) after laser-assisted subepithelial keratomileusis (LASEK).METHODS:In this prospective study, low and medium myopia group(spherical equivalent≤6.0DS) has 138 patients (276 eyes).Low concentration MMC used topically in 69 patients(138 eyes)randomized after excimer laser ablation;the another traditional LASEK as control.High myopia group(6.0DS

Objective To investigate clinical significance of computed tomography (CT) scan in diagnosis of bronchial foreign body in children.Methods Twenty-one suspected children with bronchial foreign body were studied with spiral CT cross-section scan and coronal reconstruction and diagnosis was confirmed with bronchoscopy.Results The foreign body was displayed in all of 21 cases. CT scan showed foreign body was located in right main bronchial 12 cases, right middle bronchial 1 case, right inferior lobar bronchial 2 cases and left main bronchial 6 cases. Foreign bodies were extracted with bronchoscopy.Conclusion CT scan can display and locate accurately foreign body in bronchial of children,and has very important diagnostic value in patients having atypical histories, clinical and radiological findings.

Objective To observe the levels of serum leptin in Gaves disease(GD)and thyroiditis(HT)Datients and to discuss the immunological role of leptin in the pathogenesis of autoimmune thyroid disease(AITD).Methods 102 newly diagnosed female AITD patients were divided into 3 groups:GD hyperthyroid group,HT hypothyroid group and subclinical hypothyroid group.Age,sex and BMI-matched 27 euthyroid,healthy subjects served as controis.The levels of FT3,FT4 and sTSH were determined by immunofluorometrie assay.ELISA kit was aDplied to measure the levels of serum leptin.Results Serum FT3 and FT4[(19.74±15.39),(78.25±58.68)pmol/L]levels of GD hyperthyroid patients were obviously higher than those of the controls[(4.87±0.25),(15.96±3.15)pmol/L,P＜0.01],but serum sTSH and leptin levels[(0.15±0.08)mU/L,(8.73±1.92)μg/L]were obviously lower than those of the controls[(3.81±0.19)mU/L,(12.38±3.51)μg/L,P＜0.01or＜0.05].Serum FT3 and FT4[(3.36±0.26),(6.95±3.29)pmol/L]levels of HT hypothyroid patients were obviously lower than those of the controls(P＜0.05),but serum sTSH and leptin levels[(45.48±35.83)mU/L,(17.17±3.82)μg/L]were obviously higher than those of the controls(P＜0.01 or＜0.05).Serum FT3 and FT4[(4.67±0.60),(14.87±2.14)pmol/L]levels of subclinical hypothyroid patients had not statistical difference comparing with those of the controls(P＞0.05),but serum sTSH and leptin levels[(13.67±8.66)mU/L,(16.25±3.67)μg/L]were obviously higher than those of the controls(P＜0.01 or＜0.05).Conclusions Leptin might have an immuoregulation role in the pathogenesis of AITD.In addition,serum levels of leptin in AITD is also influenced by many other related hormones.

OBJECTIVETo evaluate colon targeting characteristic of Kuikang colon targeted pellets (KCP) with determination of residual baicalin and baicalein concentration in gastrointestinal tract (GIT).

METHODThe baicalin and baicalein were assayed by HPLC. The recovery differences of the drug between KCP and conventional pellets from GIT were investigated, three and six hours after administration.

RESULTThe baicalin recovery of KCP (70%) from rat GIT was higher than that of CP (about 20%). Most of KCP were intact at 3 h after oral administration, and distributed in lower ileum. It indicated that release site of KCP was in lower ileum and colon. Six hours later, a small amount of baicalin was recovered in intestime, which showed that the release of baicalin from KCP was complete.

CONCLUSIONThe determination of residual baicalin in rat GIT was feasibility for evaluating KCP. The result confirmed KCP of colon targeting property.

Animals ; Colon ; metabolism ; Drug Delivery Systems ; Drug Implants ; Drugs, Chinese Herbal ; administration & dosage ; metabolism ; Flavanones ; metabolism ; Flavonoids ; metabolism ; Ileum ; metabolism ; Logistic Models ; Rats ; Rats, Wistar