Urinary inorganic phosphorus determinations

The Parekh-Jung method for determination of inorganic phosphorus in serum was applied to its determination in urine. Accuracy is good. The mean percentage recovery of added phosphorus was 100.2%. Forty analyses of a sample gave a mean value of 46.71 mg/100 ml +/- 0.76 standard deviation (between-batch precision). The relative usefulness of the Parekh-Jung method compared with those other methods is discussed.     

淫羊藿苷去蛋白无机牛骨复合材料与去蛋白无机牛骨材料修复下颌骨缺损

文题释义：去蛋白无机牛骨：是采用化学提纯法从牛骨中提取的碳酸磷灰石晶体，去除了蛋白及其他的有机成分，而保留了多孔天然骨的无机机构，与人体骨的结构相似，目前已被广泛应用于口腔临床骨再生手术。 淫羊藿苷：是一种具有补肾壮阳、祛风除湿功效的中药，临床多用于免疫力低下、性功能障碍与抗衰老食疗等。淫羊藿苷是淫羊藿的有效药理成分，近年来的研究发现其具有防治骨质疏松，并且其可促进间充质干细胞、成骨细胞的成骨分化与成血管因子的表达。 背景：去蛋白无机牛骨与人体骨的结构相似，目前已被广泛应用于口腔临床骨再生手术，但其缺乏成骨诱导能力。近年来的研究发现淫羊藿具有防治骨质疏松的作用。 目的：观察淫羊藿苷去蛋白无机牛骨复合材料修复下颌骨缺损的效果。 方法：将小鼠成骨细胞MC3T3-E1分别接种于淫羊藿苷去蛋白无机牛骨复合材料(观察组)与去蛋白无机牛骨材料(对照组)上，培养7 d后，活死染色观察材料表面细胞的存活，扫描电镜观察材料表面细胞的黏附；培养5，10 d后，检测细胞分泌碱性磷酸酶情况。在30只新西兰大白兔双侧下颌骨制作13 mm×6 mm×4 mm的全层骨缺损，右侧植入淫羊藿苷去蛋白无机牛骨复合材料(实验侧)，左侧植入去蛋白无机牛骨材料(对照侧)，术后4，8，12周获取双侧下颌骨组织，分别进行锥形束CT检测、组织学观察与改良Gomori染色观察。实验获得牡丹江医学院实验动物中心伦理委员会批准。结果与结论：①活死染色显示，两组材料表面的成骨细胞生长状态良好；②扫描电镜显示，成骨细胞可在两种材料表面黏附，在观察组材料表面的黏附数量更多、分布更加均匀；③观察组培养10 d的细胞碱性磷酸酶活性高于对照组(P < 0.05)；④锥形束CT显示，实验侧骨缺损至术后12周时基本愈合，对照侧术后12周时仍可见骨缺损；⑤术后12周组织学观察显示，实验侧缺损区可见大量成熟骨组织，仅见少量残余材料，可见少量脂肪组织；对照侧虽然材料部分降解，可见较多的新生骨组织，骨成熟度低于实验侧；⑥术后12周改良Gomori染色显示，实验侧可见大量成熟度较高的新生骨组织，对照侧也可见较多成熟度较高的骨组织，但骨量与骨成熟度均不及实验侧；⑦结果表明相对于去蛋白无机牛骨材料，淫羊藿苷去蛋白无机牛骨复合材料可促进下颌骨缺损的修复。ORCID: 0000-0001-5823-7228(董文杰)中国组织工程研究杂志出版内容重点：生物材料；骨生物材料; 口腔生物材料; 纳米材料; 缓释材料; 材料相容性；组织工程     

The inorganic dust pneumoconioses

Collectively, the pneumoconioses represent a spectrum of pulmonary diseases initiated by inorganic dust exposure. Although multiple humoral and cellular immune alterations have been demonstrated in these interstitial and commonly fibrotic lung diseases, the exact role of immune changes in disease pathogenesis presently is undefined. Insight into disease mechanisms may have to await the careful characterization of suitable animal models, along with analysis of local, human bronchopulmonary immune responses through the vehicle of bronchoalveolar lavage.     

Inner-medullary organic osmolytes and inorganic electrolytes in K depletion

The renal concentrating defect typical for chronic K depletion has been ascribed to malfunction of renomedullary cells caused by inadequate accumulation of organic osmolytes. A reduction in intracellular ionic strength, which is believed to influence decisively the accumulation of organic osmolytes, has been held responsible for insufficient osmolyte accumulation. To test this hypothesis, intra- and extracellular Na, Cl and K concentrations, the major determinants of ionic strength, were measured in the papilla by electron microprobe analysis and organic osmolytes (glycerophosphorylcholine, betaine, sorbitol, myo-inositol, free amino acids) in inner-medullary tissue by HPLC in antidiuretic rats kept on either a control (normal-K) or a K-deplete (low-K) diet and in euhydrated rats with free access to water and control diet. K depletion was associated with a reduced urine concentrating ability. Papillary interstitial ionic strength (sum of Na, Cl and K) in antidiuretic low-K rats was significantly reduced compared with antidiuretic normal-K rats (688+/-19 vs. 971+/-61 mmol/kg wet wt) but was similar to that in euhydrated normal-K rats (643+/-35 mmol/kg wet wt). The lower interstitial ionic strength in antidiuretic low-K and euhydrated normal-K rats was associated with a lower total content of organic osmolytes in the inner medulla (365+/-14 and 381+/-20, respectively, vs. 465+/-11 mmol/kg protein in antidiuretic normal-K rats). Intracellular ionic strength (sum of Na, Cl and K) of papillary collecting duct cells, however, was similar in antidiuretic normal-K and euhydrated normal-K rats (171+/-5 and 179+/-11 mmol/kg wet wt) but lower in antidiuretic low-K rats (138+/-9 mmol/kg wet wt). These results do not support the view that, in the steady state of osmotic adaptation of renomedullary cells in situ, intracellular ionic strength is the decisive factor for maintaining high levels of organic osmolytes. During chronic K depletion, reduced osmolyte accumulation by renomedullary cells may be the consequence, rather than the cause, of lower medullary interstitial tonicity.     

Membrane permeability for inorganic phosphate ion

The need for a more efficient removal of inorganic phosphate ions from the blood of uremic patients has led to the quest for blood-compatible semipermeable membranes with a high permeability for phosphate ions. Commercial hemodialysis membranes, various hydrogel-type membranes and a number of collodionbased charged membranes were compared. Positively charged collodion membranes were found most promising for future application in hemodialysis or hemoperfusion systems.     

Electrospun inorganic and polymer composite nanofibers for biomedical applications

Engineered nanofibers are generally focused on filtration, solar cells, sensors, smart textile fabrication, tissue engineering, etc. Electrospun nanofibers have potential advantages in tissue engineering and regenerative medicine, because of the ease in the incorporation of drugs, growth factors, natural materials, and inorganic nanoparticles in to these nanofiber scaffolds. Electrospun nanofiber scaffolds composed of synthetic and natural polymers are being explored as scaffolds similar to natural extracellular matrix for tissue engineering. The requirement of the inorganic composites in the nanofiber scaffolds for favouring hard and soft tissue engineering applications is dealt in detail in the present review. Regarding drug delivery applications of the composite nanofibers, the review emphasizes on wound healing with silver nanoparticles incorporated nanofibers, bone tissue engineering, and cancer chemotherapy with titanium and platinum complexes loaded nanofibers. The review also describes gold nanoparticle loaded nanofibers for cancer diagnosis and cosmetic applications.     

Current progress in inorganic artificial biomaterials

In this review, recent advances in bioceramics, metallic biomaterials, and their composites are discussed in terms of their material properties and new medical applications. Porous calcium phosphate ceramics have attracted a lot attention as scaffolds for tissue-engineering purposes since the porous structure allows bone ingrowth. The addition of biodegradable polymers like chitosan, gelatin, and collagen have modified the degradability of the ceramics and their mechanical properties. Titanium (Ti) alloys are being developed for the fabrication of medical devices for the replacement of hard tissue such as artificial hip joints, bone plates, and dental implants because they are very reliable from the viewpoint of mechanical performance. Physical treatment such as grooving or setting a spatial gap on the surface of materials is applicable to improve the apatite formation on the Ti alloys. Blood-compatible polymers such as poly(ethylene glycol) have been successfully fixed on the surface of Ti via chemical bonding by an electrodeposition method. New functions have been explored in Ni-free, Co–Cr–Mo alloys and Mg alloys. In addition, yttrium-containing or phosphorus-containing glass microspheres (20–30 μm in diameter) and ferrimagnetic ceramic particles have exhibited great potential to realize minimally invasive treatment of cancer without surgical operation via in situ radiotherapy or hyperthermia of cancer, but it is still a major challenge to clarify the biological reaction between the artificial implants and living body before their application.     

Polymorphonuclear phagocytosis and killing in workers exposed to inorganic mercury

The ability of neutrophils to phagocytose and kill Candida species as well as the splenic phagocytic function were investigated in workers from a mercury-producing plant. In the neutrophil phagocytosis study, two species of Candida were used in since in individuals with myeloperoxidase deficiency neutorphils are unable to kill Candida albicans, while Candida pseudotropicalis can be effectively lysed. Phagocytosis of both antigens and splenic phagocytic function were normal in all the workers studied. However, following ingestion of the organisms there was considerable reduction in the ability of neutrophils from exposed workers to kill both species of Candida, and this was not explained by a mild impairment of phagocytosis. After improvement in the hygiene conditions in the factory, a new evaluation was performed, 6 months later, in the same workers and urinary mercury concentrations were determined monthly in each worker. Despite a significant reduction in urinary mercury concentrations, a greater impairment in the ability of neutrophils to kill C. albicans was observed. The killing of C. pseudotropicalis presented no further impairment when compared to the previous evaluation. These results suggest that impairment of the lytic activity of neutrophils from workers with urinary mercury concentrations within the safe level for exposed population is due, at least in part, to some interference with myeloperoxidase activity. In addition, the mercury-NADPH complex, once formed, could limit the utilization of reduced pyridine nucleotides by NADPH- dependent enzymes such as NADPH oxidase, thereby inhibiting the PMN respiratory burst.     

Genotoxicity of inorganic lead salts and disturbance of microtubule function

Lead compounds are known genotoxicants, principally affecting the integrity of chromosomes. Lead chloride and lead acetate induced concentration-dependent increases in micronucleus frequency in V79 cells, starting at 1.1 microM lead chloride and 0.05 microM lead acetate. The difference between the lead salts, which was expected based on their relative abilities to form complex acetato-cations, was confirmed in an independent experiment. CREST analyses of the micronuclei verified that lead chloride and acetate were predominantly aneugenic (CREST-positive response), which was consistent with the morphology of the micronuclei (larger micronuclei, compared with micronuclei induced by a clastogenic mechanism). The effects of high concentrations of lead salts on the microtubule network of V79 cells were also examined using immunofluorescence staining. The dose effects of these responses were consistent with the cytotoxicity of lead(II), as visualized in the neutral-red uptake assay. In a cell-free system, 20-60 microM lead salts inhibited tubulin assembly dose-dependently. The no-observed-effect concentration of lead(II) in this assay was 10 microM. This inhibitory effect was interpreted as a shift of the assembly/disassembly steady-state toward disassembly, e.g., by reducing the concentration of assembly-competent tubulin dimers. The effects of lead salts on microtubule-associated motor-protein functions were studied using a kinesin-gliding assay that mimics intracellular transport processes in vitro by quantifying the movement of paclitaxel-stabilized microtubules across a kinesin-coated glass surface. There was a dose-dependent effect of lead nitrate on microtubule motility. Lead nitrate affected the gliding velocities of microtubules starting at concentrations above 10 microM and reached half-maximal inhibition of motility at about 50 microM. The processes reported here point to relevant interactions of lead with tubulin and kinesin at low dose levels.