Microbial induced calcium carbonate precipitation (MICP) refers to the natural biological process of calcium carbonate precipitation induced by microbial metabolism in its surrounding environment. Based on the principles of MICP, microbial cement has been developed and has received widespread attention in the field of biology, civil engineering, and environment owing to the merits of environmental friendliness and economic competence. Urease and carbonic anhydrase are the key enzymes closely related to microbial cement. This review summarizes the genes, protein structures, regulatory mechanisms, engineering strains and mutual synergistic relationship of these two enzymes. The application of bioinformatics and synthetic biology is expected to develop biocement with a wide range of environmental adaptability and high performance, and will bring the MICP research to a new height.
Calcium Carbonate/metabolism* ; Chemical Precipitation ; Urease/metabolism*

OBJECTIVE: To investigate the effect of RUNX2 gene overexpression vector modified exosomes derived from bone marrow mesenchymal stem cells (BMSCs) combined with calcium carbonate scaffold system in bone defect. METHODS: Rabbit BMSCs were used as the research object, and BMSCs were identified by flow cytometry. Construct RUNX2 gene overexpression vector, transfect BMSCs with lentivirus, and collect exosomes by ultracentrifugation. The morphology of exosomes was observed by transmission electron microscope, the expression of exosome marker CD63 was detected by Western blot, and the calcium carbonate scaffold was constructed by three chamber parallel automatic temperature control reaction system. According to whether the RUNX2 gene overexpression vector was transfected or not, the complex of BMSCs and calcium carbonate scaffold was divided into three groups, namely BMSCs group, RUNX2 overexpression group and exosome group. The osteogenic differentiation of BMSCs was detected by oil red O staining and RT-PCR. There were 9 clean adult healthy male New Zealand white rabbits, aged (12.97±1.21) months, with a body weight of (19.3±3.6) kg, with 3 rabbits in each group. The animal model of skull defect was constructed by surgical method, and the repair of bone defect was evaluated by imaging, he staining and Masson staining. RESULTS: The results of flow cytometry showed that the expression of CD29 protein, CD44 protein, CD11b protein and CD45 protein on the surface of BMSCs were 99.5%, 100%, 0.1% and 0.1%, respectively. Transmission electron microscopy showed that the exosomes were bilayer vesicles with a diameter of 50 to 150 nm. Western blot showed that the molecular marker CD63 of exosomes was positive. Oil red O staining showed that the osteogenic differentiation of BMSCs in exosome group was significantly higher than that in RUNX2 overexpression group and BMSCs group. The results of RT-PCR showed that the relative expressions of RUNX2, BMP-2 and ALP mRNA in BMSCs in exosome group were significantly higher than those in RUNX2 overexpression group and BMSCs group (P<0.05). The imaging results showed that the repair effect of skull defect in exosome group was better than that in RUNX2 overexpression group. HE staining and Masson staining showed that the repair effect of skull defect in exosome group was better than that in RUNX2 overexpression group (P<0.05). MSCs in exosome group was significantly higher than that in RUNX2 overexpression group and BMSCs group. The results of RT-PCR showed that the relative expressions of RUNX2, BMP-2 and ALP mRNA in BMSCs in exosome group were significantly higher than those in RUNX2 overexpression group and BMSCs group(P<0.05). The imaging results showed that the repair effect of skull defect in exosome group was better than that in RUNX2 overexpression group. HE staining and Masson staining showed that the repair effect of skull defect in exosome group was better than that in RUNX2 overexpression group(P<0.05). CONCLUSION Compared with RUNX2 gene overexpression vector transfection, extraction of exosomes directly can promote the differentiation of BMSCs into osteoblasts more efficiently, and the combination with calcium carbonate scaffold can better promote the healing of bone defects. So as to provide new ideas and methods for the clinical treatment of bone defects.
Animals ; Calcium Carbonate/metabolism* ; Core Binding Factor Alpha 1 Subunit/metabolism* ; Exosomes/metabolism* ; Humans ; Male ; Osteogenesis/genetics* ; RNA, Messenger/metabolism* ; Rabbits

Concrete is the most widely used modern building material. It is easy to crack under the action of stress, which makes the concrete structure permeable, affecting the durability and integrity of the structure, and thus shortening its service life. Microbial in-situ remediation technology is a low cost, effective and green way for concrete crack repairing. Due to its excellent biocompatibility, service life elongation, economic losses and environmental pollution reduction, microbial in-situ remediation technology has been intensively investigated. Bacillus has attracted much attention because of its excellent biomineralization ability, extremely strong environmental tolerance and long-term survival ability of its spores. In order to promote the research, development and large-scale application of microbial in-situ healing of concrete, the paper reviews the mechanism of spore-based in-situ healing of concrete, the survival of spores exposed in concrete, the influence of spores and external additives on the mechanical properties of concrete, progress in research and development of healing agent as well as healing effects. Moreover, future research focuses such as improving the survival ability of spores in the harsh environment of concrete, reducing the influence of external additives on the mechanical properties of concrete, and strengthening the healing effect of actual field applications are also summarized.
Bacillus ; Calcium Carbonate ; Construction Materials ; Spores, Bacterial ; Technology

Dioscorea tokoro has long been used in Korean traditional medicine as a pain killer and anti-inflammatory agent. A 53-year-old male who consumed water that had been boiled with raw tubers of D. tokoro as tea presented with numbness and spasm of both hands and feet. Laboratory results showed hypocalcemia, hypoparathyroidism, and vitamin D insufficiency. During his hospital stay, colitis, acute kidney injury, and toxic encephalopathy developed. The patient received calcium gluconate intravenous infusion and oral calcium carbonate with alfacalcidol. His symptoms improved gradually, but hypocalcemia persisted despite the calcium supplementation. We suggest that ingestion of inappropriately prepared D. tokoro can cause symptomatic hypocalcemia in patients with unbalanced calcium homeostasis.
Acute Kidney Injury ; Calcium ; Calcium Carbonate ; Calcium Gluconate ; Colitis ; Dioscorea ; Eating ; Foot ; Hand ; Homeostasis ; Humans ; Hypesthesia ; Hypocalcemia ; Hypoparathyroidism ; Infusions, Intravenous ; Length of Stay ; Male ; Medicine, Korean Traditional ; Middle Aged ; Neurotoxicity Syndromes ; Spasm ; Tea ; Vitamin D ; Water

Vitamin D hydroxylation-deficient rickets type 1A (VDDR1A, OMIM 264700) is a rare autosomal recessive inherited disorder. Pathogenic variants in the CYP27B1 gene lead to loss of 1α-hydroxylase activity. We report the case of a 22-month-old toddler who presented with growth retardation and delayed development. The patient exhibited the typical laboratory findings of VDDR1A, including hypocalcemia (calcium: 5.2 mg/dL), elevated serum level of alkaline phosphatase (2,600 U/L), elevated serum level of intact-parathyroid hormone (238 pg/mL), low 1,25(OH)₂D₃ level (11.2 pg/mL), and normal 25(OH)D₃ level (40.7 ng/mL). His height and weight were 76.5 cm and 9.5 kg, respectively (both <3rd percentile). The Bayley Scales of Infant and Toddler Development II indicated significantly delayed development (mental development index <50, psychomotor development index <50). The patient was a compound heterozygous for two novel pathogenic variants in the CYP27B1 gene: c.57_69del (p.Glu20Profs*2) and c.171dupG (p.Leu58Alafs*275), inherited from his mother and father, respectively. The patient showed remarkable improvement after treatment with calcitriol and calcium carbonate.
25-Hydroxyvitamin D3 1-alpha-Hydroxylase ; Alkaline Phosphatase ; Calcitriol ; Calcium Carbonate ; Databases, Genetic ; Fathers ; Humans ; Hypocalcemia ; Infant ; Mothers ; Rickets ; Vitamin D ; Vitamins ; Weights and Measures

The aim of this study was to investigate the pattern of distribution of mating type (MAT) genes of Tuber indicum in ectomycorhizosphere soils from natural T. indicum-producing areas and cultivated truffle orchards and ascocarp samples from different regions. Quantitative real-time PCR and multiplex PCR were used to weight the copy numbers of MAT1-1-1 and MAT1-2-1 in natural truffle soils and cultivated orchard soils. The effect of limestone on the pattern of truffle MAT genes and the correlation between soil properties and the proportion of MAT genes were also assessed. These results indicated that an uneven and nonrandom distribution of MAT genes was common in truffle-producing areas, cultivated truffle orchards, and ascocarps gleba. The competition between the two mating type genes and the expansion of unbalanced distribution was found to be closely related to truffle fructification. Limestone treatments failed to alter the proportion of the two mating type genes in the soil. The content of available phosphorus in soil was significantly correlated with the value of MAT1-1-1/MAT1-2-1 in cultivated and natural ectomycorhizosphere soils. The application of real-time quantitative PCR can provide reference for monitoring the dynamic changes of mating type genes in soil. This study investigates the distributional pattern of T. indicum MAT genes in the ectomycorhizosphere soil and ascocarp gleba from different regions, which may provide a foundation for the cultivation of T. indicum.
Calcium Carbonate ; Multiplex Polymerase Chain Reaction ; Phosphorus ; Polymerase Chain Reaction ; Real-Time Polymerase Chain Reaction ; Soil

OBJECTIVES: There are many drugs for of symptomatic fibroids. Gonadotropin-releasing hormone (GnRH) agonists are the well known drugs. Also, aromatase inhibitors are effective. All published studies surveyed the effect of one of these two drugs. In this study as the first study decided to evaluate the effectiveness of the combination of GnRH agonists + aromatise inhibitor on the uterine fibroids. METHODS: A cross-sectional prospective case series study was performed on 10 known cases of uterine fibroids late perimenopause, at least 3 myomas >5 cm, abnormal uterine bleeding and anemia due to fibroids, candidate for hysterectomy, no tendency to surgery. A single dose of Diphereline 11.25 mg, SR plus 2.5 mg of Letrozole daily for 4 weeks with add-back therapy + calcium carbonate were used. The second dose of Diphereline 11.25 mg, SR was used 3 months after the first injection. The patients were followed until 3 years. RESULTS: The mean age of the study group was 49.90 ± 1.66. The mean fibroid size reduced from 15.05 ± 57.20 cm to 13.56 ± 39.39 cm (P = 0.012) and fibroid volume reduced from 72.78 ± 110.6 to 50.96 ± 64.2 (P = 0.116). There was no signification changes in the serum level of hormones at the end of six months. Eight cases were menopause at the end of the study and hypoestrogenism symptoms did not happened in none of the cases until the end of 24 months. Except in one case, there was no need to do surgery on others. CONCLUSIONS: Combination of Diphereline + Letrozole probably could prevent surgery in cases that have multiple fibroids, perimenopause, anemic and candidate for surgery.
Anemia ; Aromatase Inhibitors ; Aromatase ; Calcium Carbonate ; Female ; Gonadotropin-Releasing Hormone ; Humans ; Hysterectomy ; Leiomyoma ; Menopause ; Myoma ; Perimenopause ; Prospective Studies ; Uterine Hemorrhage

Pancreatolithiasis, or pancreatic calculi (PC), is a sequel of chronic pancreatitis (CP) and may occur in the main ducts, side branches or parenchyma. Calculi are the end result, irrespective of the etiology of CP. PC contains an inner nidus surrounded by successive layers of calcium carbonate. These calculi obstruct the pancreatic ducts and produce ductal hypertension, which leads to pain, the cardinal feature of CP. Both endoscopic therapy and surgery aim to clear these calculi and decrease ductal hypertension. In small PC, endoscopic retrograde cholangiopancreatography (ERCP) followed by sphincterotomy and extraction is the treatment of choice. Large calculi require fragmentation by extracorporeal shock wave lithotripsy (ESWL) prior to their extraction or spontaneous expulsion. In properly selected cases, ESWL followed by ERCP is the standard of care for the management of large PC. Long-term outcomes following ESWL have demonstrated good pain relief in approximately 60% of patients. However, ESWL has limitations. Per oral pancreatoscopy and intraductal lithotripsy represent techniques in evolution, and in current practice their use is limited to centers with considerable expertise. Surgery should be offered to all patients with extensive PC, associated multiple ductal strictures or following failed endotherapy.
Calcium Carbonate ; Calculi* ; Cholangiopancreatography, Endoscopic Retrograde ; Constriction, Pathologic ; Humans ; Hypertension ; Lithotripsy ; Pancreatic Ducts ; Pancreatitis, Chronic ; Shock ; Standard of Care

Pancreatolithiasis, or pancreatic calculi (PC), is a sequel of chronic pancreatitis (CP) and may occur in the main ducts, side branches or parenchyma. Calculi are the end result, irrespective of the etiology of CP. PC contains an inner nidus surrounded by successive layers of calcium carbonate. These calculi obstruct the pancreatic ducts and produce ductal hypertension, which leads to pain, the cardinal feature of CP. Both endoscopic therapy and surgery aim to clear these calculi and decrease ductal hypertension. In small PC, endoscopic retrograde cholangiopancreatography (ERCP) followed by sphincterotomy and extraction is the treatment of choice. Large calculi require fragmentation by extracorporeal shock wave lithotripsy (ESWL) prior to their extraction or spontaneous expulsion. In properly selected cases, ESWL followed by ERCP is the standard of care for the management of large PC. Long-term outcomes following ESWL have demonstrated good pain relief in approximately 60% of patients. However, ESWL has limitations. Per oral pancreatoscopy and intraductal lithotripsy represent techniques in evolution, and in current practice their use is limited to centers with considerable expertise. Surgery should be offered to all patients with extensive PC, associated multiple ductal strictures or following failed endotherapy.
Calcium Carbonate ; Calculi* ; Cholangiopancreatography, Endoscopic Retrograde ; Constriction, Pathologic ; Humans ; Hypertension ; Lithotripsy ; Pancreatic Ducts ; Pancreatitis, Chronic ; Shock ; Standard of Care

Oleanolic acid-precipitated calcium carbonate solid dispersion was prepared by using solvent evaporation method. The microscopic structure and physicochemical properties of solid dispersion were analyzed using differential scanning calorimetry and scanning electron microscopy (SEM). And its in vitro release also was investigated. The properties of the precipitated calcium carbonate was studied which was as a carrier of oleanolic acid solid dispersion. Differential scanning calorimetry analysis suggested that oleanolic acid may be present in solid dispersion as amorphous substance. The in vitro release determination results of oleanolic acid-precipitated calcium carbonate (1: 5) solid dispersion showed accumulated dissolution rate of.oleanolic acid was up to 90% at 45 min. Accelerating experiment showed that content and in vitro dissolution of oleanolic acid solid dispersion did not change after storing over 6 months. The results indicated that in vitro dissolution of oleanolic acid was improved greatly by the solid dispersion with precipitated calcium carbonate as a carrier. The solid dispersion is a stabilizing system which has actual applied value.
Calcium Carbonate ; chemistry ; Calorimetry, Differential Scanning ; Chemistry, Pharmaceutical ; Drug Carriers ; chemistry ; Drug Stability ; Microscopy, Electron, Scanning ; Oleanolic Acid ; chemistry ; Plant Extracts ; chemistry ; Solubility