Alternative Complement Pathway Is Activated and Associated with Galactose-Deficient IgA1 Antibody in IgA Nephropathy Patients.

Background: Galactose-deficient IgA1 (Gd-IgA1) and alternative complement pathway activation are considered to be involved in the pathogenesis of IgA nephropathy (IgAN). Nevertheless, the relationships between alternative pathway activation and disease activity or Gd-IgA1 level remains unclear. Methods: Ninety-eight biopsy-diagnosed IgAN, twenty-five primary focal segmental sclerosis (FSGS) patients and forty-two healthy individuals were recruited in this study. Among them, fifty IgAN patients received immunosuppression. Follow-up blood samples at 1 and 3~6 months after immunosuppression were collected. Plasma levels of complement C5a, factor Ba and Gd-IgA1 were measured and analyzed. Immunostaining for complement was performed in twenty-five IgAN and FSGS patients. Results: At baseline, IgAN patients had higher levels of plasma C5a, factor Ba and Gd-IgA1 than control subjects. Gd-IgA1 levels positively correlated with plasma C5a and factor Ba. In addition, levels of factor Ba and Gd-IgA1 were positively associated with proteinuria and negatively associated with renal function. Immunostaining revealed positive staining for factor Bb and C3c in glomeruli in IgAN patients, but not in FSGS patients. At baseline, patients receiving immunosuppression had more severe proteinuria and higher factor Ba. After 6 months, eGFR declined and proteinuria persisted in patients without immunosuppression. In contrast, patients who received immunosuppression exhibited decreased plasma levels of C5a, factor Ba, and Gd-IgA1 as early as 1 month after treatment. Proteinuria decreased and renal function also remained stable 6 months after immunosuppression. Conclusions: Our results indicate a close relationship between alternative complement pathway activation, Gd-IgA1 concentration and clinical severity of IgAN. Level of complement factor B may be a potential marker for disease activity and therapeutic target in IgAN patients.

Risk of nephrogenic systemic fibrosis in patients with impaired renal function undergoing fixed-dose gadoxetic acid-enhanced magnetic resonance imaging.

PURPOSE: To assess the risk of nephrogenic systemic fibrosis (NSF) in patients with renal impairment undergoing gadoxetic acid-enhanced magnetic resonance imaging. METHODS: This retrospective study included patients who had an estimated glomerular filtration rate (eGFR) below 60 mL/min per 1.73 m2 or had undergone dialysis around the time of gadoxetic acid exposure from January 2010 to November 2019. All patients received at least one intravenous injection of gadoxetic acid at a fixed dose of 2.5 mmol. The primary endpoint was the development of NSF after exposure to gadoxetic acid based on Girardi's clinicopathological scoring system. RESULTS: A total of 204 patients with renal impairment received 424 injections of gadoxetic acid, of which 131 and 54 had an eGFR of 30-59 and < 30 mL/min per 1.73 m2, respectively, and 19 had undergone hemodialysis. Eighty-two patients received multiple injections, with 23 receiving five or more injections. The dose of each exposure ranged from 0.02 to 0.07 mmol/kg and the cumulative doses ranged from 0.02 to 0.45 mmol/kg. Thirty-three patients had concomitant Child-Pugh class B or C cirrhosis. No NSF was detected during follow-up (median 20 months; range 6 days to 111 months). The upper bound of the 95% confidence interval for NSF risk was 2.2% and 1.1% per patient and examination, respectively. CONCLUSION: No NSF was detected in this study. However, it is premature to ascertain the risk of NSF using gadoxetic acid in patients with renal impairment and further studies are warranted.

Dual roles of Lys(57) at the dimer interface of human mitochondrial NAD(P)+-dependent malic enzyme.

Human m-NAD(P)-ME [mitochondrial NAD(P)+-dependent ME (malic enzyme)] is a homotetramer, which is allosterically activated by the binding of fumarate. The fumarate-binding site is located at the dimer interface of the NAD(P)-ME. In the present study, we decipher the functional role of the residue Lys57, which resides at the fumarate-binding site and dimer interface, and thus may be involved in the allosteric regulation and subunit-subunit interaction of the enzyme. In the present study, Lys57 is replaced with alanine, cysteine, serine and arginine residues. Site-directed mutagenesis and kinetic analysis strongly suggest that Lys57 is important for the fumarate-induced activation and quaternary structural organization of the enzyme. Lys57 mutant enzymes demonstrate a reduction of Km and an elevation of kcat following induction by fumarate binding, and also display a much higher maximal activation threshold than WT (wild-type), indicating that these Lys57 mutant enzymes have lower affinity for the effector fumarate. Furthermore, mutation of Lys57 in m-NAD(P)-ME causes the enzyme to become less active and lose co-operativity. It also increased K0.5,malate and decreased kcat values, indicating that the catalytic power of these mutant enzymes was significantly impaired following mutation of Lys57. Analytical ultracentrifugation analysis demonstrates that the K57A, K57S and K57C mutant enzymes dissociate predominantly into dimers, with some monomers present, whereas the K57R mutant forms a mixture of dimers and tetramers, with a small amount of the enzyme in monomeric form. The dimeric form of these Lys57 mutants, however, cannot be reconstituted into tetramers with the addition of fumarate. Modelling structures of the Lys57 mutant enzymes show that the hydrogen bond network in the dimer interface where Lys57 resides may be reduced compared with WT. Although the fumarate-induced activation effects are partially maintained in these Lys57 mutant enzymes, the mutant enzymes cannot be reconstituted into tetramers through fumarate binding and cannot recover their full enzymatic activity. In the present study, we demonstrate that the Lys57 residue plays dual functional roles in the structural integrity of the allosteric site and in the subunit-subunit interaction at the dimer interface of human m-NAD(P)-ME.

[Determination of molybdenum in supported catalysts by ICP-AES].

The supported Mo catalysts were pretreated using hydrofluoric acid. Then Mo was determined by inductively coupled plasma atomic emission spectrometry(ICP-AES). In the present method, the detection limit of Mo was 8.220 ng x mL(-1), the recovery of standard addition was 102.6%-104.3%, the relative standard deviation (n = 11) was less than 0.860%. The method is efficient, accurate, and easy to operate. Molybdenum in supported catalysts, which were prepared under different conditions, was determined by this method. The results showed that the content of Mo in supported catalysts decreased after preparation. The decreases in the content of Mo were different when the active component concentrations in impregnation solution, and the calcination temperature, changed.

[Decoloring and spectral properties analysis of innoxious ultraviolet absorbents].

The ultraviolet absorbent extracted from mango leaves, was discolored by some decoloring agent. Then the spectral properties of the discolored ultraviolet absorbents were analyzed. The discolored method of ultraviolet absorbent was studied by comparing one with the others. The results showed that the discoloring effect was satisfactory by using active carbon, H2O2, citric acid, and oxalic acid as decoloring agent. Specially, when oxalic acid was used as decoloring agent, the color of the production was slight, the rate of production was high, and the absorption effect of ultraviolet ray was well. When the concentration of the ultraviolet absorbent solution is 0.5% (w/w), the ultraviolet ray transmission was smaller than 0.3% in 200-370 nm, and it increased slightly from 370 nm. There was a maximum value at 400 nm, approaching 12%.

[Extraction and spectral properties analysis of innoxious ultraviolet absorbents].

Some dozens of ultraviolet absorbents were extracted from leaves of pure natural plants, such as frangipani, mango, and sweet-scented osmanthus. Then the spectral properties of these ultraviolet absorbents were analyzed. The plant that has the best effect of absorbing ultraviolet ray was selected by comparing one with the others. And the method of extracting ultraviolet absorbent was studied. The results showed that the method, which used leaves of mango as material, distilled water as extracted solvent, and alcohol as precipitator, was satisfactory. When the concentration of ultraviolet absorbent solution is 1% (w/w), the ultraviolet ray transmission is smaller than 1% in 200-400 nm. The rate of production is 1.5%. It is innoxious.

[Pretreatment of lead-antimony alloy and determination of antimony and selenium using ICP-AES].

The sample was obtained from original sample using "sawing method" and was dissolved with a mixed solvent of nitric acid and tartaric acid. After the sample solution was pretreated with a series of methods, Sb and Se were determined by inductively coupled plasma atomic emission spectrometry (ICP-AES). The results show that the recovery of standard addition of Sb was 96.2% and that of Se was 92.1%, and that the relative standard deviations (n=11) were smaller than 3.56%. The method is efficient, accurate and easy to operate, and has been applied to the determination of Sb and Se in Pb-Sb alloy products with satisfactory results.

[Pretreatment of supported Wacker catalysts and the determination of palladium and copper].

The supported Wacker catalysts were pretreated with two different methods. Then copper and palladium were determined by inductively coupled plasma atomic emission spectrometry(ICP-AES). The results showed that the best pretreatment method is burning-acid dissolving. With this method, the detection limits of Pd and Cu were 3.127 and 2.548 ng x mL(-1), the recoveries of standard addition of Pd and Cu were 96.26% and 94.82%, and the relative standard deviations (n=11) of Pd and Cu were less than 1.237% and 1.354%, respectively. The method is efficient, accurate, and easy to operate. Pd and Cu in supported Wacker catalysts, which were sampled before calcination, after calcination and after reaction, were determined by this method, and the contents were compared with calculated values. The percentages were larger than 96.4% and 96.6% respectively. It is considered that the active components did not decrease in preparation and reaction.

[Analysis of spectral properties of oil matrix raw materials in skin care products].

There are many kinds of oil matrix raw materials used in skin care products. Their spectral properties are different. The matrix raw material that has better ultra-violet absorption will enhance the sun-screening agent effect obviously. In the present article the spectral properties of six oil matrix raw materials often used in skin care products were mainly measured and analyzed by spectrophotometer. The analysis of T-lambda spectra shows that castor oil can absorb ultraviolet as well as near infrared light. It was shown that castor oil chosen as the matrix raw material will improve the effect of sun-screening agent and enhance the products. The function of sun-screening agent and skin health care product will stand out clearly.

[Determination of twenty one elements in lithium hexafluorophosphate by ICP-AES].

One gram (+/- 0.0001 g) of lithium hexafluorophosphate was weighed exactly under dry atmosphere and was dissolved with an adequate amount of dimethyl carbonate (DMC). After the sample solution was pretreated with a series of methods, Be, Cu, Pb, Ca, Zr, Co, Mg, V, Ti, Mo, Ni, Mn, Sr, Zn, K, Al, Ba, Cd, Fe, Cr and Na were determined by ICP-AES. The results show that the recoveries of standard addition were 93.3%-102.1%, and the relative standard deviations (n = 11) were 0%-3.56%. The method is efficient, accurate and easy to operate. It has been applied to the determination of lithium hexafluorophosphate products with satisfactory results.

[Study on spectral properties of natural plant ultraviolet absorbent].

Natural plant ultraviolet absorbent is a safe cosmetic-typed ultraviolet additive, with no side-effect and bright future. Natural plant ultraviolet absorbent is ground from ultraviolet absorbing plant into organic solvent under dry-vacuum condition. This new type of ultraviolet absorbent has brown colour in solid form, but when it mixes with alcohol and water, its colour changes to light yellow in liquid form. This paper focuses mainly on using ultraviolet/visible spectrometer to examine its spectral properties under ultraviolet light. The result shows that this absorbent has a relative transmittance below 0.2% in the UVC and UVB zones, while in the UVA zone around 375 nm, the value raises up only to 2.1%. This concludes that the natural plant ultraviolet absorbent has a high absorbing ability under ultraviolet light and can withstand ultraviolet light with long wavelength.

[Study on spectral properties of Chinese herbal medicines additives in cosmetic].

Chinese herbal medicines as additives in cosmetic can both keep the properties of cosmetic and have maintaining, health protection and remedial effect. Some of the Chinese herbal medicines can absorb ultraviolet and cure sunburn. This article mainly studies the spectral properties of several kinds of Chinese herbal medicine additives in cosmetic by ultraviolet and visible spectrophotometer, and analyses the ultraviolet absorption of the Chinese herbal medicine additives. It was shown that gynostemma pentaphyllum can absorb ultraviolet very well. It can be a promising natural additive in the health protection cosmetic. Codonopsis pilosula, floss chrysanthemum indicum, radix scutellariae and radix glycyrrhizae can absorb ultraviolet. They can also be the additives, while ligusticum wallichii can't absorb ultraviolet, so it can not be used as the sunburn protection additive.

[Determination of Se in serum by ICP-AES].

The serum sample solution was prepared by using acid digestion and the Se concentration in it was determined by ICP-AES. At the same time, the interference from Fe and the interference-free method were studied. The results showed that the recovery of standard addition was 91.6%, the relative standard deviation(n = 10) was 2.147% and when KOH was added to the sample solution the interference was reduced greatly. The method is efficient, accurate and easy to operate.