Intermittent sliding-lock-knot suture for limbal conjunctival autograft fixation in pterygium surgery: a technique note.

AIM: To report a technique used with intermittent sliding-lock-knot (ISLK) fixation for limbal conjunctival autografts in pterygium surgery and compared with those of routine intermittent (RI) fixation. METHODS: Consecutive patients with primary pterygium who had undergone pterygium excision combined with limbal conjunctival autograft transplantation between March 2021 and March 2022 at our institute were retrospectively analyzed. Primary outcome measures were mean duration of surgery and suture removal, degree of conjunctival hyperemia on postoperative day 1, pain score at suture removal, postoperative symptoms at 6mo, including conjunctival hyperemia, foreign body sensation, and graft stability. RESULTS: Ninety-eight patients underwent monocular surgery and were divided into ISLK (51 eyes) and RI (47 eyes) groups according to the type of conjunctiva autograft fixation method planned. There was no significant difference in mean duration of surgery between the two groups (18.59±2.39min vs 18.15±2.20min, P=0.417); however, compared to the RI group, shorter suture removal times were observed in the ISLK group [0.58min (0.42-0.87) vs 3.00min (2.21-4.15), P<0.001]. The degree of conjunctival hyperemia on postoperative day 1 was milder in the ISLK group (P<0.001). Pain scores at suture removal were lower in the ISLK group than in RI group [1 (0-3) vs 2 (1-4), P<0.001]. Postoperative symptoms at 6mo were comparable between the groups (P=0.487), with no recurrence. CONCLUSION: ISLK is an innovative method for limbal conjunctival autograft fixation after pterygium excision. Compared to RI fixation, ISLK facilitates suture removal and reduces discomfort, with comparable surgery duration and less conjunctival hyperemia.

Heparin-free continuous vena-venous hemofiltration as a veno-venous bypass in inferior vena cava reconstruction.

OBJECTIVE: This paper investigated the effects of continuous vena-venous hemofiltration on inferior vena cava reconstruction. METHOD: Totally, 11 patients were observed, vascular access in right internal jugular vein and femoral vein catheterization was established guided by ultrasound, and heparin-free continuous vena-venous hemofiltration was used to substitute for extracorporeal veno-venous bypass. Furthermore, blood pressure, central venous pressure, urine volume, blood platelet, serum albumin, renal function, serum cystatin C, CRP, TBil, AST, ALT, serum amylase, serum lipase, PLT, PT, APTT, Fig, D-mier, and adverse events were determined. RESULTS: All operations were completed successfully. Average time of continuous vena-venous hemofiltration was 2.96 ± 0.76 h. No hematoma and blood leakage was occurred when catheters were inserted, and no luminal stenosis and catheter-related infections were observed. Visceral congestion was observed when the inferior vena cava was clamped, but significantly improved immediately after the continuous vena-venous hemofiltration was begun. No hemofilter was changed due to clotting during continuous vena-venous hemofiltration therapy. Blood pressure, central venous pressure, and urine volume of the patients maintained stable. No significant change was observed in blood platelet, serum albumin, and serum creatinin. Serum cystatin and hsCRP increased after operation, but still in normal level. CONCLUSION: Heparin-free continuous vena-venous hemofiltration was an effective mode as veno-venous bypass in the treatment of inferior vena cava interruption and reconstruction.

[Spectrophotometric determination of aromatic amino compounds with J-acid].

The problems such as chromogenic reaction selectivity, reaction rate, sensitivity and water-solubility of azo compounds were considered. The molecular structures of coupling components were theoretically designed and screened in the present research The reaction conditions and methods of chromogenic reaction were investigated. J-Acid (2-amino-5-naphthol-7-sulfonic acid) as a coupling reagent to determine aromatic amino compounds was established. In the presence of potassium bromide, at room temperature, nitrite reacted with aromatic amino compounds in the medium of thin hydrochloric acid. Then diazonium salt reacted with J-Acid in the aqueous solution of sodium carbonate, forming coloured azo dye, which had a maximum adsorption at 480 nm. The molar adsorption coeffcients of aniline, 4-aminobenzene sulfonic acid and 1-naphthylamine were 3. 95 X 10(4), 3. 24 X 10(4) and 3. 91 X 10(4) L . mol-1 . cm-1 , respectively. Experimental results showed that common coexisting ions on the surface water did not affect the results of determination. J-Acid of spectrophotometry was used to determine the samples of Shanghai Fu Xing Dao canal. Meanwhile, recovery experiments by standard addition method were done. Experiment results showed that the recoveries of aniline were in the range of 98. 5%-102. 1%, and RSD was 2. 08%. J-Acid is a common organic reagent. It is soluble in water and low volatile, and its toxicity is much lower than N-ethylenediamine. spectrophotometric determination of aromatic amino compounds by J-Acid has the advantage of high sensitivity, good selectivity, simple rapid operation and accurate results, and thus it can be used for the determination of trace aromatic amino compounds in the environmental water.

[Preliminary study on human bone marrow mesenchymal stem cells differentiation into epithelial-like cells].

OBJECTIVE: To investigate the differentiation potential of human bone marrow mesenchymal stem cells (hMSC) inducing into epithelial-like cells, even corneal epithelial-like cells, and to discuss the plasticity that make hMSC the seed cells used in corneal tissue engineering. METHODS: hMSC were isolated and purified by density gradient centrifugation combined with an attachment culture method and passaged in vitro. hMSC were identified by flow cytometry. The passaged hMSC were planted on fresh pig corneal Bowman's membrane. The expression of CK12, ABCG2 and CK19 in hMSC was identified by immunofluorescence staining. We used in vitro method to obtain a multilayer culture of hMSC. When hMSC formed a monolayer, the cells were inserted to Millicell culture and grew into multilayers by using the air-lifting cultivation methodology. Four weeks later, after fixed and dehydrated, the hMSC were observed under the light microscope after hemotoxylin and eosin (HE) and immunohistochemistry staining. RESULTS: hMSC could be cultured, expanded in vitro, and showed great potential of proliferation. The result of flow cytometry showed that the positive staining percentage was 0.06% for CD45, 0.41% for CD34, 86.43% for CD44, 85.72% for CD29 and 90.72% for CD105. This indicated that hMSC expressed CD44, CD29, CD105 but not CD45 and CD34. After four weeks induction, part of hMSC expressed CK12 and CK19 but not ABCG2. In the in vitro stratification, HE and immunohistochemical staining showed that there were one or two layers epithelial-like cells, even corneal epithelial-like cells after using the air-lifting cultivation. CONCLUSIONS: This study suggests that hMSC have the potential to differentiate into epithelial cells, even corneal epithelial cells. hMSC could be the option of cells used to reconstruct the corneal epithelium by tissue engineering technology.

[Study and spectrophotometric determination of nitrite with sulfanilamide and N-phenyl J-Acid system].

In the present article, compounds used in diazotizing-coupling reaction were selected. The conditions and methods of diazotizing-coupling chromogenic reaction were studied. A new method of diazotizing-coupling spectrophotometry with sulfanilamide(p-aminobenzene sulfonamide) and J-Acid series dye intermediates (N-phenyl J-Acid, J-Acid, Di-J-Acid) to determine nitrite was developed. At room temperature, in the presence of potassium bromide, nitrous acid reacted with sulfanilamide in the medium of thin hydrochloric acid. Then diazonium salt reacted with N-phenyl J-Acid in the aqueous solution of sodium carbonate, forming coloured azo compounds. The apparent molar absorptivity was 4.63 x 10(4) L x mol(-1) x cm(-1). The Beer's law was obeyed in the range of 0.003-0.7 mg x L(-1). The recoveries were in the range of 99.5%-101.6%. RSD was 2.1%. This method has been used for the determination of trace nitrite in the environmental water.

Highly enantioselective hydrovinylation of alpha-alkyl vinylarenes. an approach to the construction of all-carbon quaternary stereocenters.

The highly enantioselective hydrovinylation of alpha-alkyl vinylarenes was realized by using nickel complexes of chiral spiro phosphoramidite ligands. The method provided a new approach to the construction of chiral all-carbon quaternary centers.

Enantioselective rhodium-catalyzed addition of arylboronic acids to aldehydes using chiral spiro monophosphite ligands.

[reaction: see text] Highly efficient rhodium-catalyzed asymmetric addition of arylboronic acids to aldehydes has been realized by using chiral spiro monophosphite ligands, affording diarylmethanols in excellent yields and good enantiomeric excesses.

[Study on visible spectra of Victoria Pure Blue and its association complexes].

The visible spectrums of Victoria Pure Blue (VPB) and its association complexes were studied, and the chromogenic reaction of VPB with anions was also studied. The proton conduction constant of VPB in water solution was determined by plot method. The composition and stable constant were measured by equimolar continuous change method and the molar ratio method. The color of VPB in acid solution was light yellow while that of its association complex was pure blue. The pKh values of VPB BO, VPB R, VPB B and NB were 2.16, 1.32, 0.82 and 0.73 respectively. The molar ratio of association complex formed by the reaction of VPB BO with DBS was 1:1, while the ratio of VPB BO to [CdI4]2- was 2:1. The Kf (Stability constant) value of the two compounds was 1.5 x 10(6) and 6.0 x 10(12) respectively. The apparent molar absorptivity of them was respectively 4.7 x 10(4) L x mol(-1) x cm(-1) and 2.8 x 10(5) L x mol(-1) x cm(-1). It is clear that VPB is a high-sensitivity chromogenic reagent with fine analytical properties.

[Study and spectrophotometric determination of trace silver with iodide-Victoria Pure Blue BO system].

Analytical properties and spectra of naphthyl diphenymethane basic dyes and associated complexes of dye with [AgI2]- was studied. A new method for the spectrophotometric determination of trace amount of silver was developed. The method was based on the Victoria Pure Blue BO reacted with [AgI2]- to form blue associated complex in the buffer medium of H3PO4 -NaH2PO4. The spectrophotometric measurements were directly carried out at 574 nm, the apparent molar absorptivity of associated complex was 7.25 x 10(4) L x mol(-1) x cm(-1). The Beer's law was obeyed in the range of 4-250 microg x L(-1). The recoveries were in the range of 97.0%-98.3%. RSD was 2.7%. The method has been used to determination of trace silver in river water with satisfactory results.

Copper-catalyzed asymmetric ring opening of oxabicyclic alkenes with Grignard reagents.

[reaction: see text] Simple Grignard reagents were applied in copper-catalyzed asymmetric ring-opening reactions of oxabenzonorbornadiene derivatives using spiro phosphoramidite ligands. Excellent anti-stereoselectivities and good enantioselectivities were achieved.

Highly enantioselective copper-catalyzed conjugate addition of diethylzinc to enones using chiral spiro phosphoramidites as ligands.

Novel monodentate chiral spiro phosphoramidite ligands have been readily synthesized in good yields from enantiomerically pure 1,1'-spirobiindane-7,7'-diol. The new ligands were highly efficient in the copper-catalyzed conjugate addition of Et(2)Zn to enones with up to 98% enantiomeric excess.