Osteoblast-Based Therapy-A New Approach for Bone Repair in Osteoporosis: Pre-Clinical Setting

BACKGROUND

Osteoporosis is a metabolic bone disease characterized by low bone density resulting in increased fracture susceptibility. This research was constructed to uncover the potential therapeutic application of osteoblasts transplantation, generated upon culturing male rat bone marrow-derived mesenchymal stem cells (BM-MSCs) in osteogenic medium (OM), OM containing gold (Au-NPs) or gold/hydroxyapatite (Au/HA-NPs) nanoparticles, in ovariectomized rats to counteract osteoporosis.

METHODS

Forty rats were randomized into: (1) negative control, (2) osteoporotic rats, whereas groups (3), (4) and (5) constituted osteoporotic rats treated with osteoblasts yielded from culturing BM-MSCs in OM, OM plus Au-NPs or Au/HA-NPs, respectively. After 3 months, osterix (OSX), bone alkaline phosphatase (BALP), sclerostin (SOST) and bone sialoprotein (BSP) serum levels were assessed. In addition, gene expression levels of cathepsin K, receptor activator of nuclear factor-κb ligand (RANKL), osteoprotegerin (OPG) and RANKL/OPG ratio were evaluated using real-time PCR. Moreover, histological investigation of femur bone tissues in different groups was performed. The homing of implanted osteoblasts to the osteoporotic femur bone of rats was documented by Sex determining region Y gene detection in bone tissue.

RESULTS

Our results indicated that osteoblasts infusion significantly blunted serum BALP, BSP and SOST levels, while significantly elevated OSX level. Also, they brought about significant down-regulation in gene expression levels of cathepsin K, RANKL and RANKL/OPG ratio versus untreated osteoporotic rats. Additionally, osteoblasts nidation could restore bone histoarchitecture.

CONCLUSION

These findings offer scientific evidence that transplanting osteoblasts in osteoporotic rats regains the homeostasis of the bone remodeling cycle, thus providing a promising treatment strategy for primary osteoporosis.

Influence of Temperature and pH on the Nonenzymatic Reduction of Triphenyltetrazolium Chloride

The effects of temperature and pH on the nonenzymatic (chemical) reduction of triphenyltetrazolium chloride (TTC) to triphenyl formazan (TF) in cheese whey and municipal solid waste compost samples were studied. Ten different incubation temperatures and 13 pH levels were tested. The study showed that the TTC could be reduced nonenzymatically at high temperatures and/or under alkaline pH conditions. The nonenzymatic TTC reduction was observed at pH values greater than 9.5 and 11.0 for the cheese whey and compost, respectively. The TTC chemical reduction rate followed the same trend in both media. The TF content increased with increasing the pH value, reaching its maximum at a pH of 12, then decreased and was not detected at a pH of 13. The TTC was also reduced nonenzymatically at temperatures higher than 70 and 85 degrees C for cheese whey and compost, respectively. Evaporation did not seem to have any significant effect on the TTC chemical reduction since less than 3% of water content was lost at a temperature of 100 degrees C. It was noticed that the TF yield in cheese whey samples was higher than that in compost samples. This was due to the higher moisture content of cheese whey and the presence of copper in the compost samples, which reacted chemically with the TF causing reduction in the red color. For a given incubation period, the effect of pH on the TTC chemical reduction was more significant than the effect of incubation temperature (at a 2 h incubation period, 57.5% and 17.9% of the TTC were chemically reduced at a pH of 12 compared to 10.9% and 7.7% at an incubation temperature of 100 degrees C, for cheese whey and compost, respectively). Among the six metals tested (Ca, Cu, K, Na, Ni, and Zn) only Cu affected the color intensity of the TF. The activation energy of the TTC chemical reduction was 168,808 and 239,102 J/mol in cheese whey and municipal solid compost, respectively. For dehydrogenase activity measurement, the pH of the samples and the incubation temperature should not be higher than 9 and 60 degrees C in order to ensure that the TTC reduction is caused only by the biochemical reaction. Measuring the color intensity of TF in waste samples that contain copper could give misleading results as a result of the formation of formazan copper complex, which reduces the red color.

On-Line Sterilization of Cheese Whey Using Ultraviolet Radiation

The effectiveness of ultraviolet radiation for on-line sterilization of cheese whey was investigated. The effects of flow rate and residence time on the performance of three UV reactors having different gap sizes (18, 13, and 6 mm) were studied. Six flow rates and six residence times were tested with the three UV reactors. The cheese whey used in this study had a very high turbidity (4317 NTU), very poor transmittance in the UV radiation germicidal range ( approximately 0%), and high percentage of large solid particles ( approximately 20% > 100 microm). Although the cheese whey physical characteristics showed low probability of sterilization using UV radiation, the study showed that UV radiation can be used on-line to sterilize cheese whey if the proper reactor gap size and the appropriate residence time are used. There were combined effects of the flow rate and gap size. The cell removal efficiency increased with increases in residence time and decreases in the UV reactor gap size. Removal efficiency of 100% was not achieved in this study with the first UV reactor (18-mm gap size), whereas 100% removal efficiency was achieved with the second (13-mm gap size) and third (6-mm gap size) UV reactors at residence times of 2.0 and 0.5 h, respectively. The microbial decay rates achieved in this study were 4.94, 7.62, and 20.9 h(-)(1) using the first, second, and third UV reactor, respectively. Residence times of 3.3, 2.1, and 0.8 h would be required to completely destruct a microbial population of 5.95 x 10(6) cells/mL using the first, second, and third UV reactors, respectively. Although cheese whey sterilization using UV radiation seems to be a good alternative to pasteurization, increases in cheese whey temperature resulted in lamp fouling. If online sterilization is to be used, the fouling problem should be investigated and a maintenance scheme for the UV reactor should be developed.

Effects of tetrazolium chloride concentration, O2, and cell age on dehydrogenase activity of Aspergillus niger

The effects of triphenyl tetrazolium chloride (TTC) concentration, cell age, and presence of O2 on the dehydrogenase activity of Aspergillus niger as measured by triphenyl formazan (TF) yield were investigated. The results indicated that increasing TTC concentration initially increased the TF yield and then decreased it. The maximum TF yield was observed at a TTC concentration of 30 g/L for young cells (4 d old) and 20 g/L for old cells (12 d old). Conducting the test under anaerobic conditions increased the TF yield. About 18% of the TF produced was converted back into TTC in the presence of oxygen. The relationship between dehydrogenase activity of A. niger (as measured by TF yield) and cell mass was found to be linear. A kinetic model describing the relationship between reaction rate (micromoles of TF formed per hour) and TTC concentration while accounting for substrate inhibition was developed, and the model constants were calculated. The optimum TTCtest conditions for dehydrogenase activity measurement of A. niger were a TTC concentration of 20 g/L, a pH of 9.0, a temperature of 55 degrees C, an incubation time of 3 h, and anaerobic conditions.

On the possible leakage of ET-RR1 liquid waste tank: hydrological and migration modes studies

The first Egyptian (ET-RR1) research reactor has been in operation since 1961 at the Egyptian Atomic Energy Authority (EAEA) Inshas site. Therefore, at present, it faces a serious problem due to aging equipment, especially those directly in contact with the environment such as the underground settling tanks of nuclear and radioactive waste. The possible leakage of radionuclides from these aging tanks and their migration to the aquifer was studied using instantaneous release.This study was done based on the geological and hydrological characteristics of the site, which were obtained from the hydrogeological data of 25 wells previously drilled at the site of the reactor[1]. These data were used to calculate the trend of water levels, hydraulic gradient, and formulation of water table maps from 1993–2002. This information was utilized to determine water velocity in the unsaturated zone.Radionuclides released from the settling tank to the aquifer were screened according to the radionuclides that have high migration ability and high activity. The amount of fission and activation products of the burned fuels that contaminated the water content of the reactor pool were considered as 10% of the original spent fuel. The radionuclides considered in this case were H-3, Sr-90, Zr-93, Tc-99, Cd-113, Cs-135, Cs-137, Sm-151, Pu-238, Pu-240, Pu-241, and Am-241.The instantaneous release was analyzed by theoretical calculations, taking into consideration the migration mechanism of the various radionuclides through the soil space between the tank bottom and the aquifer. The migration mechanism through the unsaturated zone was considered depending on soil type, thickness of the unsaturated zone, water velocity, and other factors that are specific for each radionuclide, namely retardation factor, which is the function of the specific distribution coefficient of each radionuclide. This was considered collectively as delay time. Meanwhile, the mechanism of radionuclide migration during their passage in the water body of the aquifer was the main focus of this study.The degree of water pollution in the aquifer at a point of contact with the main water body of Ismailia Canal 1000 m from the reactor site was assessed for the instantaneous release by comparing the results obtained with the regulations of the standard limit of radionuclides in drinking water[2,3].

Phytoremediation of aquaculture wastewater for water recycling and production of fish feed

Five plants were examined for their ability to remove nutrients from aquaculture wastewater and suitability as fish feed: alfalfa, white clover, oat, fall rye, barley. The seeds were first germinated in water in a hydroponic system, and the plants were fed wastewater from Tilapia production facility. Clover and alfalfa seeds were infected with fungus shortly after germination, and their roots were completely destroyed by day 14. Oat, rye and barley had the fastest growth and showed greater tolerance to fungal disease compared with alfalfa and clover. Although substantial amounts of soluble and insoluble substances were released by the seeds during the germination period, the plants were able to remove all the pollutants in wastewater and significant portions of those released substances. The total reductions in total solids, COD, NO3-N, NO2-N, phosphate and potassium ranged from 54.7% to 91.0%, 56.0% to 91.5%, 82.9% to 98.1%, 95.9% to 99.5%, 54.5% to 93.6% and 99.6% to 99.8%, respectively. Oat, barley and rye grow well in this type of hydroponic system and can be used as a fish feed after being supplemented with fat, Ca, Na, Mn and Fe. Oil seeds and the chlorides of these elements could be added to these plants when formulating the fish feed. For a continuous operation, a two-unit system could be configured to allow for one week germination and one week cleaning and startup in one unit while the other unit is in operation.

Organic and Inorganic Fouling at Quartz–Liquid Interface in Ultraviolet Photoreactors During On-Line Sterilization of Cheese Whey

This article reports on lamp fouling during on-line ultraviolet (UV) sterilization of cheese whey. The extent of fouling as well as the composition of fouling materials was studied after the operation of three tubular UV reactors of different flow thicknesses (18, 13, and 6 mm) for 48 h at a 2-h residence time. Lamp fouling, which significantly affected the sterilization efficiency, was realized after an extended period of operation. The extent of lamp fouling increased with a decrease in the thickness of the flowing cheese whey (14.42, 15.31, and 25.25 g for 18-, 13-, and 6-mm thickness, respectively). A strong relationship between the extent of fouling and the steady-state outlet temperature was observed. The fouling material contained 63.51 to 77.19% protein, 12.57 to 16.49% fat, and 6.51 to 9.47% minerals on dry weight bases compared with 1% protein, 0.5% fat, and 0.4% minerals in raw cheese whey. The organic and inorganic material concentrations in the fouling material increased with a decrease in the flow thickness. The fouling mechanism was owing to adsorption and direct ion exchange, which were enhanced by the high temperature and low pH attained in the study. Improved designs of UV reactors in which the contact between the flowing material and the quartz surface should be developed.

Influence of ambient air temperature on the cooling/heating load of a single cell protein jacketed fermenter operating on cheese whey under continuous conditions

The heat generated by mixing and lactose metabolism, during the continuous production of single cell protein from cheese whey lactose using a jacketed fermenter with running cooling water, was calculated using a heat balance equation. The technique quantified the heat produced in and lost from the fermentation unit. Most of the heat generated by mixing in the cell-free system (97.47%) was lost with exhaust gas, while a very small amount (2.53%) was lost through the fermenter lid, wall, and bottom. The heat generated by mixing was significant (26.31% of the total heat generated in the fermentation system with an active yeast population present) and, therefore, cannot be ignored in heat balance calculations. About 19.71% of the total heat generated in the reactor was lost through the coolant at an ambient temperature of 22 +/- 0.5 degrees C, showing the need for a cooling system. A yeast population size of 986 million cells/mL and a lactose removal efficiency of 95.6% were observed. About 72.5% and 27.5% of the lactose consumed were used for growth and respiration, respectively. A yield of 0.66 g of cells/g of lactose was achieved. The heat released by unit biomass was 7.05 kJ/g of cells. The results showed the significant impact of ambient air temperature on the cooling load. The heat to be removed from the medium by the cooling system varied from 3.46 to 281.56 kJ/h when the temperature increased from 16 to 30 degrees C. A heating system is needed to maintain the medium temperature at 34 degrees C when the ambient air temperature is below 16 degrees C.