Amount Of Alkaline Phosphatase Research Articles

Effects of different lipid sources with or without a probiotic on gastrointestinal tract, immune system and blood parameters of chickens: An animal model.

The objective of this study was to determine the effects of different lipid sources, with or without a probiotic, on the gastrointestinal tract, immune system and blood parameters of Ross 308 male chickens. In this study, 360 one-day-old chickens were randomly allotted to six treatments with six replicates. Experimental diets were: (1) control (CTL); (2) a diet containing 30 g/kg lipid from tallow (CTL+TLW); (3) a diet containing 30 g/kg lipid from soybean oil (CTL+SO); (4) the basal diet plus a probiotic (CTL+PRO), (5) a diet containing 30 g/kg tallow plus probiotic (TLW+PRO); and (6) a diet containing 30 g/kg soybean oil plus probiotic (SO+PRO). The percentage of liver and jejunum in the treatments that used tallow alone or tallow with probiotics had a significant increase as compared to the control. The villus height and crypt depth of the ileum and villus height/crypt depth in the treatments that used soybean oil and probiotic alone had a significant increase compared to the control. The weight of the spleen, bursa of Fabricius, and thymus in the treatments that used probiotics had a significant increase compared to the control. The amount of alkaline phosphatase and alanine aminotransferase as well as triacylglycerol in the treatment containing probiotic and its mixture with soybean oil had the least significant difference with the control. The results showed that the use of soybean oil, probiotics, and their mixture can improve intestinal morphology, strengthen the immune system, and reduce liver enzymes in chickens.

The Construction of Alkaline Phosphatase-Responsive Biomaterial and Its Application for In Vivo Urinary Tract Infection Therapy.

Urinary tract infections caused by urinary catheter implantations are becoming more serious. Therefore, the construction of a responsive antibacterial biomaterial that can not only provide biocompatible conditions, but also effectively prevent the growth and metabolism of bacteria, is urgently needed. In this work, a benzophenone-derived phosphatase light-triggered antibacterial agent is designed and synthesized, which is tethered to the biological materials using a one-step method for in vivo antibacterial therapy. This surface could kill gram-positive bacteria (Staphylococcus aureus) and gram-negative bacteria (Escherichia coli). More importantly, because this material exhibited a zwitterion structure, it does not damage blood cells and tissue cells. When the bacteria interact with this surface, the initial fouling of the bacteria is reduced by zwitterion hydration. When the bacteria actively accumulate and metabolize to produce a certain amount of alkaline phosphatase, the surface immediately started the sterilization performance, and the bactericidal effect is achieved by destroying the bacterial cell membrane. In summary, an antibacterial biomaterial that shows biocompatibility with mammalian cells is successfully constructed, providing new ideas for the development of intelligent urinary catheters.

Effects of Avocado (Persea Americana) and Sesame (Seasame Indicum) Seeds in the Management of Dmba-Induced Neoplasm in Wistar Albino Rats

Cancer, a genetic disease, is one of the leading causes of death all over the world. Many plants have been reported as being useful in its management, as chemotherapy destroys the normal cells along with cancer cells. Alternative safer therapies such as herbal therapies are becoming increasingly more popular. This research determined the anti- neoplastic effect of avocado (Persea americana) and sesame (Sesame indicum) seeds on 7, 12- dimethylbenz[a]anthracene (DMBA)-induced neoplasm in albino rats. Standard methods were used to determine the phytochemical constituents, proximate and mineral composition of avocado and sesame seeds. Biochemical, haematological and histological studies were also carried out. Thirty albino rats divided into five groups of six each were used for the study. Result showed that tannins and flavonoids were present in both avocado and sesame seeds; whereas saponins were only detected in avocado. The protein content was higher in sesame (17.64%) than in avocado (1.47%). Mineral analysis showed the presence of potassium, sodium, calcium, iron, phosphorus, magnesium and zinc in both seeds. The total red blood cells of the animals ranged from 6.64 x1012/L to 8.92 x1012/L. The lymphocyte for control group, and groups 1, 2, 3 and 4 were 65%, 76%, 73%, 62% and 95% respectively. The amount of alkaline phosphatase (ALP) was highest in group 4 (1352 μ/L) and least in group 3 (230 μ/L). There was no necrosis in the liver, skin, voice cord and mammary gland, except the mucosal gland of the colon of the neoplastic rats that showed some levels of tissue damage. A proof that organ injuries might not have occurred were evident in Alanine Transaminase (ALT) and Aspartate Transaminase (AST) levels which were not significantly different between the treated and the control groups. It can be concluded from this study that avocado and sesame seeds exert significant anti-neoplastic properties in rats

ВЛИЯНИЕ СОЛЕЙ СВИНЦА НА БИОХИМИЧЕСКИЕ ПОКАЗАТЕЛИ В ЛИМФЕ ЖИВОТНЫХ

The article establishes the effect on the biochemical parameters of animal lymphocytes in case of poisoning with lead salts. The impact of lead salts, their spread, the effect of the harmful factors and the strengthening of the ecological situation in the environment determine the urgency of this problem. It is known that heavy metal ions gradually accumulate in the elements of the environment and then pass from the atmosphere to water and the human body. It was found that the effect of heavy metal salts in rats, including lead salts, has a negative effect on the lymphatic and circulatory system compared to the control group of biochemical parameters, which leads to metabolic disorders in the blood and lymph circulation. As a result of the study, the activity of rat enzymes was detected in normal and after poisoning with a toxicant. In acute poisoning, there was an increase in the amount of alkaline phosphatase in the lymphatic system by 40%, as well as an increase in the level of amino-transferase enzymes by 71% and 83%, respectively, and a decrease in the content of total bilirubin and associated bilirubin, all this indicates a violation of liver function, increased cytological processes in the liver and pancreas, decreased protein synthesis and impaired metabolism. When exposed to lead salts on the biochemical parameters of the lymph, the activity of α-amylase was reduced by 22.7%. based on the experiments, it was found that heavy metal salts significantly reduce the level of glucose in the blood, which negatively affects the parenchyma of the liver, kidney and kidney, increasing its consumption in tissues. The results obtained in the course of the study allowed us to form comprehensive data on the effect of lead on lymphatic and circulatory activity, biochemical parameters of the lymph of animal rats and can serve as a scientific basis for finding solutions to this problem.

Beta-Titanium Alloy Covered by Ferroelectric Coating–Physicochemical Properties and Human Osteoblast-Like Cell Response

Beta-titanium alloys are promising materials for bone implants due to their advantageous mechanical properties. For enhancing the interaction of bone cells with this perspective material, we developed a ferroelectric barium titanate (BaTiO3) coating on a Ti39Nb alloy by hydrothermal synthesis. This coating was analyzed by scanning electron and Raman microscopy, X-ray diffraction, piezoresponse force microscopy, X-ray photoelectron spectroscopy, nanoindentation, and roughness measurement. Leaching experiments in a saline solution revealed that Ba is released from the coating. A progressive decrease of Ba concentration in the material was also found after 1, 3, and 7 days of cultivation of human osteoblast-like Saos-2 cells. On day 1, the Saos-2 cells adhered on the BaTiO3 film in higher initial numbers than on the bare alloy, but they were less spread, and their initial proliferation rate was slower. These cells also contained a lower amount of beta1-integrins and vinculin, i.e., molecules involved in cell adhesion, and produced a lower amount of collagen I. This cell behavior was attributed to a higher surface roughness of BaTiO3 film rather than to its potential cytotoxicity, because the cell viability on this film was very high, reaching almost 99%. The amount of alkaline phosphatase, an enzyme involved in bone matrix mineralization, was similar in cells on the BaTiO3-coated and uncoated alloy, and on day 7, the cells on BaTiO3 film attained a higher final cell population density. These results indicate that after some improvements, particularly in its roughness and stability, the hydrothermal ferroelectric BaTiO3 film could be promising coating for improved osseointegration of bone implants.

Interleukin-4 repairs wear particle induced osteolysis by modulating macrophage polarization and bone turnover.

Periprosthetic osteolysis remains as a major complication of total joint replacement surgery. Modulation of macrophage polarization with interleukin-4 (IL-4) has emerged as an effective means to limit wear particle-induced osteolysis. The aim of this study was to evaluate the efficacy of local IL-4 delivery in treating preexisting particle-induced osteolysis. To this end, recently established 8week modification of murine continuous femoral intramedullary particle infusion model was utilized. Subcutaneous infusion pumps were used to deliver polyethylene (PE) particles into mouse distal femur for 4 weeks to induce osteolysis. IL-4 was then added to the particle infusion for another 4 weeks. This delayed IL-4 treatment (IL-4 Del) was compared to IL-4 delivered continuously (IL-4 Cont) with PE particles from the beginning and to the infusion of particles alone for 8 weeks. Both IL-4 treatments were highly effective in preventing and repairing preexisting particle-induced bone loss as assessed by μCT. Immunofluorescence indicated a significant reduction in the number of F4/80 + iNOS + M1 macrophages and increase in the number of F4/80 + CD206 + M2 macrophages with both IL-4 treatments. Reduction in the number of tartrate resistant acid phosphatase + osteoclasts and increase in the amount of alkaline phosphatase (ALP) + osteoblasts was also observed with both IL-4 treatments likely explaining the regeneration of bone in these samples. Interesting, slightly more bone formation and ALP + osteoblasts were seen in the IL-4 Del group than in the IL-4 Cont group although these differences were not statistically significant. The study is a proof of principle that osteolytic lesions can be repaired via modulation of macrophage polarization.

Plasmonic Colorimetric Biosensor for Sensitive Exosome Detection via Enzyme-Induced Etching of Gold Nanobipyramid@MnO2 Nanosheet Nanostructures

Exosomes involved in tumor-specific processes display excellent potential in the early diagnosis of cancer. Herein, a highly sensitive plasmonic colorimetric biosensor was proposed for exosome quantification. The sensing strategy mainly includes two steps: exosome-triggered competitive reaction and etching of gold nanobipyramid@MnO2 nanosheet nanostructures (Au NBP@MnO2 NSs). A competitive reaction between exosomes and placeholder chains induced by exosomes can translate the signal of exosomes into the amount of alkaline phosphatase, which simplifies the experimental process and amplifies the signal. The etching of Au NBP@MnO2 NSs by ascorbic acid generated from the hydrolysis of l-ascorbic acid 2-phosphate by alkaline phosphatase changes the refractive index of Au NBPs, accompanied by the blue shift of the longitudinal localized surface plasmon resonance peak. Profiting from the signal amplification of the competitive reaction and superior refractive index sensitivity of colorimetric substrates, this protocol exhibits high sensitivity toward exosomes within 8.5 × 102 to 8.5 × 104 particles μL-1, along with a detection limit of 1.35 × 102 particles μL-1, which is more sensitive than previously reported colorimetric methods. In addition, a sensitive multicolor visual detection of exosomes was realized by adjusting the aspect ratio of Au NBPs. It is worth mentioning that the Au NBP@MnO2 NSs was synthesized through in situ growth of MnO2 nanosheets on Au NBPs, and the attractive optical properties and ease of etching make Au NBP@MnO2 NSs promising candidates for plasmonic detection.

PNIPAAM modified mesoporous hydroxyapatite for sustained osteogenic drug release and promoting cell attachment

This work presented a sustained release system of simvastatin (SIM) based on the mesoporous hydroxyapatite (MHA) capped with poly(N-isopropylacrylamide) (PNIPAAM). The MHA was prepared by using cetyltrimethylammonium bromide (CTAB) as a template and the modified PNIPAAM layer on the surface of MHA was fabricated through surface-initiated atom transfer radical polymerization (SI-ATRP). The SIM loaded MHA-PNIPAAM showed a sustained release of SIM at 37°C over 16days. The bone marrow mesenchymal stem cell (BMSC) proliferation was assessed by cell counting kit-8 (CCK-8) assay, and the osteogenic differentiation was evaluated by alkaline phosphatase (ALP) activity and Alizarin Red staining. The release profile showed that the release of SIM from MHA-SIM-PNIPAAM lasted 16days and the cumulative amount of released SIM was almost seven-fold than MHA-SIM. Besides, SIM loaded MHA-PNIPAAM exhibited better performance on cell proliferation, ALP activity, and calcium deposition than pure MHA due to the sustained release of SIM. The quantity of ALP in MHA-SIM-PNIPAAM group was more than two fold than pure MHA group at 7days. Compared to pure MHA, better BMSC attachment on PNIPAAM modified MHA was observed using fluorescent microscopy, indicating the better biocompatibility of MHA-PNIPAAM.

Influence of alkaline phosphatase on phase state of the SM monolayers at the air-water interface

Abstract The Langmuir monolayer is a most suitable model membrane system to study the interfacial interaction between protein and lipid. The surface pressure-area per molecule isotherms of the SM monolayer in the presence of different amount of alkaline phosphatase have been studied in this work. The compression modulus and the interfacial mixing ratio of protein/lipid have been calculated. The different amount of alkaline phosphatase has an influence on the phase transition of SM monolayer at the air–water interface. A coexist state of liquid expanded and liquid condensed is due to the presence of alkaline phosphatase. The process of phase transition from liquid expanded state to coexist state is longer in the presence of more amount of protein. The emergence of coexistence phase state reflects the interaction of the protein and the SM monolayer. The interfacial mixing ratio at the liquid expanded state is higher than that of the coexist state of liquid expanded and liquid condensed. The images of SEM and AFM also shown the microstructure of SM monolayers at two phase states in the presence of alkaline phosphatase.

Chitosan nanofiber scaffold improves bone healing via stimulating trabecular bone production due to upregulation of the Runx2/osteocalcin/alkaline phosphatase signaling pathway.

Osteoblasts play critical roles in bone formation. Our previous study showed that chitosan nanofibers can stimulate osteoblast proliferation and maturation. This translational study used an animal model of bone defects to evaluate the effects of chitosan nanofiber scaffolds on bone healing and the possible mechanisms. In this study, we produced uniform chitosan nanofibers with fiber diameters of approximately 200 nm. A bone defect was surgically created in the proximal femurs of male C57LB/6 mice, and then the left femur was implanted with chitosan nanofiber scaffolds for 21 days and compared with the right femur, which served as a control. Histological analyses revealed that implantation of chitosan nanofiber scaffolds did not lead to hepatotoxicity or nephrotoxicity. Instead, imaging analyses by X-ray transmission and microcomputed tomography showed that implantation of chitosan nanofiber scaffolds improved bone healing compared with the control group. In parallel, microcomputed tomography and bone histomorphometric assays further demonstrated augmentation of the production of new trabecular bone in the chitosan nanofiber-treated group. Furthermore, implantation of chitosan nanofiber scaffolds led to a significant increase in the trabecular bone thickness but a reduction in the trabecular parameter factor. As to the mechanisms, analysis by confocal microscopy showed that implantation of chitosan nanofiber scaffolds increased levels of Runt-related transcription factor 2 (Runx2), a key transcription factor that regulates osteogenesis, in the bone defect sites. Successively, amounts of alkaline phosphatase and osteocalcin, two typical biomarkers that can simulate bone maturation, were augmented following implantation of chitosan nanofiber scaffolds. Taken together, this translational study showed a beneficial effect of chitosan nanofiber scaffolds on bone healing through stimulating trabecular bone production due to upregulation of Runx2-mediated alkaline phosphatase and osteocalcin gene expressions. Our results suggest the potential of chitosan nanofiber scaffolds for therapy of bone diseases, including bone defects and bone fractures.

Attenuation of copaiba oil in hepatic damage in rats.

To investigate the copaiba oil on the hepatic damage induced by acetaminophen, comparing against corn oil. Fifty four rats were distributed into nine study groups (N=6): control group, that didn't receive the acetaminophen; Acetaminophen Group, that only received the acetaminophen; Prophylactic Copaiba Group 1, that received copaiba oil two hours before the acetaminophen; Prophylactic Copaiba Group 7, that received copaiba oil seven days, once by day, before the acetaminophen; Therapy Copaiba Group, that received the copaiba oil two hours after the acetaminophen, the corn's groups were similar than copaiba oil groups; and N-Acetyl-Cysteine Group, that received the N-Acetyl-Cysteine two hours after the acetaminophen. Euthanasia was performed after 24 hours. The serum levels transaminases, bilirubin and canalicular enzymes were analyzed. The prophylactic copaiba group 7, therapy copaiba group and N-Acetyl-Cysteine Group showed amounts of AST and ALT similar to the control group; and the prophylactic copaiba group 1 and corn's groups showed similar levels to the acetaminophen group. There was no significant difference between the groups regarding the amount of alkaline phosphatase and ɤ GT (p>0.05). The therapy copaiba group showed the highest levels of total bilirubin and was statistically different from the other groups (p<0.01). Copaiba oil administered prophylactically for seven days and therapeutically 2 hours after the acetaminophen acute intoxication offered a potential hepato protection against paracetamol-induced hepatic damage, normalizing the biochemical parameters similarly to N-Acetyl-Cysteine, and the treatment with corn oil shows no effect on the liver damage.

Effect of copaiba oil in hepatic damage induced by acetaminophen in rats

To investigate the effects of copaiba oil on the hepatic damage induced by paracetamol. Thirty six rats were distributed into six study groups (N=6): control group, that didn't receive the acetaminophen; Acetaminophen Group, that only received the acetaminophen; Prophylactic Copaiba Group 1, that received copaiba oil two hours before the acetaminophen; Prophylactic Copaiba Group 7, that received copaiba oil seven days, once by day, before the acetaminophen; Therapy Copaiba Group, that received the copaiba oil two hours afther the acetaminophen; and N-Acetyl-Cysteine Group, , that received the N-Acetyl-Cysteine two hours afther the acetaminophen. Euthanasia was performed after 24 hours. The serum levels of AST, ALT, alkaline phosphatase, [formula see text] GT, total bilirubin, direct bilirubin and indirect bilirubin and histological analisis were analized. The prophylactic copaiba group 7, therapy copaiba group and N-Acetyl-Cysteine Group showed amounts of AST and ALT similar to the control group; and the prophylactic copaiba group 1 showed similar levels to the acetaminophen group. There was no significant difference between the groups regarding the amount of alkaline phosphatase and [formula see text] GT (p>0.05). The therapy copaiba group showed the highest levels of bilirubin and was statistically different from the other groups (p<0.01) and this increased the costs of direct bilirubin. Regarding histopathology, the oil of copaiba administered prophylactic or therapeutic form for 7 days could decrease the amount of necrosis and inflammatory infiltrate. Copaiba oil administered prophylactically for seven days, and therapeutic could reduce liver damage caused by paracetamol similarly N-Acetyl-Cysteine, however, when treated with copaiba therapeutically showed increases in bilirubin, costs increasing fraction indirect.

Effect of dietary supplementation of vitamin E on production performance and some biochemical characteristics of cloacal foam in male Japanese quail

This experiment was conducted to investigate the effects of increasing the level of dietary supplementation of vitamin E (VE) on production performance and biochemical characteristics of cloacal foam in male Japanese quail (Coturnix coturnix japonica).A total of 225 male Japanese quail chicks (day old) were randomly distributed to three dietary treatments for a period of 30 weeks. Each treatment comprised of three replicates, each containing 25 chicks. The basal diet (T1) contained 12.30IUVEkg−1 and the two experimental diets were supplemented with 150 and 300IUVEkg–1 (diets T2 and T3, respectively). dl-α-Tocopherol acetate was used as the source of VE. All chicks were provided feed and water ad libitum.Mean body weights, feed intake, feed conversion ratio (FCR) and mortality of the birds in the different treatment groups showed no significant differences (P>0.05), whereas a significant (P<0.05) increase (29.81 and 50.83%) in average foam weight was evident in the VE-treated groups (T2) compared with control (T1) and T3 groups. The biochemical characteristics of foam, in terms of quantities of protein and nitric oxide (NO), did not differ significantly (P>0.05), whereas the quantities of glucose (60.01%) and acid phosphatase (ACP, 32.46%) were significantly (P<0.05) higher in the T3 group. By contrast, the quantities of alkaline phosphatase (ALP), glutamic oxaloacetic transaminase (GOT) and glutamic pyruvic transaminase (GPT) were significantly (P<0.05) lower (48.84%, 10.38% and 22.08%, respectively) in the T3 group and higher in the T1 (control) and T2 groups.From this study, it can be concluded that dietary supplementation of VE to the basal diet has no effect on the production performance but supplementation of a higher level of VE (300IUkg–1diet) improved the biochemical characteristics of the foam and moderate levels of VE (150IUkg–1diet) improved the foam production of male Japanese quail.

Relationship between Dielectric Characteristic by DEP Levitation and Differentiation Activity for Stem Cells

In our previous study, we discussed the possibility of differentiation activity measurement for rat mesenchymal stem cells (RMSC) by Dielectrophoretic (DEP) levitation. Consequently, it was found that the differentiation activity of the RMSC could be evaluated by DEP levitation without the differentiation induction. Thus, we discuss the possibility of differentiation activity evaluation by DEP levitation with cells other than the RMSC. Human mesenchymal stem cells (HMSC) and human adipose tissue-derived stem cells (ASC) were used as the sample cells. The dielectric characteristics (Re[K(ω)]) measurement, the Re[K(ω)] of both the HMSC and the ASC decreased with the increasing passage number. Moreover, to evaluate the differentiation activity of the HMSC and the ASC that had performed the osteoblast differentiation induction, the amount of Alkaline Phosphatase (ALP) was measured. Consequently, the ALP activity of both the HMSC and ASC decreased with increasing the passage number. Therefore, it was found that the differentiation activity of the HMSC and the ASC could be evaluated by measuring the Re[K(ω)] due to the relationship between the Re[K(ω)] and ALP activity.

Effect of higher dietary vitamin E concentrations on physical and biochemical characteristics of semen in Kadaknath cockerels

1. This experiment was to investigate the effects of increasing dietary vitamin E on physical and biochemical characteristics of semen in Indian reared Kadaknath (KN) cockerels. DL-α-Tocopherol acetate was used as the source of vitamin E. 2. A total of 135 one-day-old male KN chicks were randomly selected and divided into 9 groups with 15 chicks in each group (3 dietary treatments × 3 replicates). 3. The basal diet contained 15 IU (10 mg) vitamin E/kg and the two experimental diets were supplemented with 150 IU (100 mg) and 300 IU (200 mg) vitamin E/kg (diets T2 and T3, respectively). 4. Physical characteristics in terms of semen volume, sperm concentration, sperm motility and percentage live sperm did not differ significantly, whereas proportion of abnormal and dead spermatozoa were significantly lower and fertility higher in the T2 group. 5. Biochemical characteristics in term of quantities of protein and nitric oxide (NO) did not differ significantly, whereas the quantity of glucose, acid phosphatase (ACP) and vitamin E were significantly higher in the T2 group. 6. In contrast, the quantities of alkaline phosphatase (ALP), glutamic oxaloacetic transaminase (GOT) and glutamic pyruvic transaminase (GPT) were significantly lower in T2 group and higher in the T1 (control) group. 7. From this study it can be concluded that moderate supplementation of dietary vitamin E may be beneficial for physical and biochemical characteristics of semen in Indian reared KN cock.

Secretory activity of neutrophilic leukocytes in inflammatory periodontal diseases

Effects of various antigens on the secretory and diagnostically important functions of neutrophilic leukocytes were studied in peripheral venous blood samples of 106 patients with inflammatory periodontal diseases without any internal pathologies. Their neutrophils, stimulated by phagocytosable particles, were found to secrete increased amounts of alkaline phosphatase, β-glucuronidase, and lysozyme. This phenomenon suggests a general activation of lysosomal enzyme secretion and shows that the destruction of periodontal tissues may be caused by these proteases.

ACTH stimulates the release of alkaline phosphatase through Gi-mediated activation of a phospholipase C and the release of inositolphosphoglycan

We have previously reported that ACTH activates a phospholipase C that hydrolyzes glycosylphosphatidylinositol (GPI), which would release inositolphosphoglycan (IPG) to the extracellular medium, and that an IPG purified from Trypanosoma cruzi is able to inhibit ACTH-mediated steroid production in adrenocortical cells. In the present paper, it was found that anti-inositolphosphoglycan antibodies (anti-CRD) increased ACTH-mediated corticosterone production, which indicates that an endogenous IPG is a physiological inhibitor of ACTH response. On the other hand, we investigated the release to the extracellular medium of the GPI-anchored enzyme, alkaline phosphatase, by ACTH. We found that: (a) the released enzyme appeared in the aqueous phase after Triton X-114 partitioning, consistent with loss of the GPI, (b) the phospholipase C inhibitor, U73122, impaired the release of the enzyme by the hormone and (c) two inhibitors of IPG uptake, inositol 2-monophosphate and 2 M NaCl, increased the amount of alkaline phosphatase in the extracellular medium. These results suggest that ACTH releases alkaline phosphatase by activation of a phospholipase C. Dibutyryladenosine-3',5'-cyclic monophosphate (db-cAMP) was able to increase the release of alkaline phosphatase from adrenocortical cells and this effect was inhibited by U73122, suggesting that cAMP is involved in the activation of phospholipase C. In addition, it was found that a pertussis-toxin sensitive G-protein is required for ACTH- and db-cAMP-mediated release of alkaline phosphatase and that incorporation of anti-Gi antibodies in adrenocortical cells inhibited the release of alkaline phosphatase by ACTH. Our results suggest that ACTH increases the release of alkaline phosphatase by activation of a phospholipase C through cAMP and Gi which would contribute to produce IPG It was also found that the two inhibitors of IPG uptake, inositol-2-monophosphate and 2 M NaCl, increased the amount of alkaline phosphatase in the extracellular medium of ACTH-treated cells more than in control cells, indicating that ACTH also stimulates the uptake of IPG These data support a role of GPI and the involvement of Gi in ACTH action.

An Increased Risk of Osteoporosis during Acquired Immunodeficiency Syndrome

Osteoporosis is characterized by decreased bone mineral density and mechanistic imbalances of bone tissue that may result in reduced skeletal strength and an enhanced susceptibility to fractures. Osteoporosis in its most common form affects the elderly (both sexes) and all racial groups of human beings. Multiple environmental risk factors like acquired immune deficiency syndrome (AIDS) are believed to be one of the causes of osteoporosis. Recently a high incidence of osteoporosis has been observed in human immunodeficiency virus (HIV) infected individuals. The etiology of this occurrence in HIV infections is controversial. This problem seems to be more frequent in patients receiving potent antiretroviral therapy. In AIDS, the main suggested risk factors for the development of osteoporosis are use of protease inhibitors, longer duration of HIV infection, lower body weight before antiretroviral therapy, high viral load. Variations in serum parameters like osteocalcin, c-telopeptide, levels of elements like Calcium, Magnesium, Phosphorus, concentration of vitamin-D metabolites, lactate levels, bicarbonate concentrations, amount of alkaline phosphatase are demonstrated in the course of development of osteoporosis. OPG/RANKL/RANK system is final mediator of bone remodeling. Bone mineral density (BMD) test is of added value to assess the risk of osteoporosis in patients infected with AIDS. The biochemical markers also aid in this assessment. Clinical management mostly follows the lines of treatment of osteoporosis and osteopenia.

Skeletal tissue growth, differentiation and mineralization in the NASA Rotating Wall Vessel

The NASA Rotating Wall Vessel (RWV) is a device that creates a unique environment that supports three-dimensional tissue growth, a heightened level of cell differentiation and randomizes the position of the downward gravitational force on cells. Embryonic bone formation encompasses a cascade of chondrogenic and osteogenic events, which can be altered by changes in gravitational loading. These studies were conducted to determine if the chondrogenic cascade in bone formation would be enhanced or hindered in the unique culture environment of the RWV. Embryonic mouse pre-bone tissues were placed in the RWV at one of four different stages of chondrogenesis, ranging from undifferentiated mesenchyme cells to chondrocytes on the verge of undergoing terminal chondrocyte differentiation. After culture, tissues were analyzed for their size, the amount of alkaline phosphatase (ALP) activity and their ability to form a mineralized matrix. Tissue consisting of cells at the early phase of chondrogenesis grew very little and did not differentiate or mineralize when cultured in the RWV. Some tissues were cultured for short periods in the RWV then cultured in standard culture dishes (SCD). Following this culture regime, the cartilage grew only a small amount, but alkaline phosphatase activity increased, and some mineralized regions formed. The pattern of mineralization was abnormal, with two mineralized zones at each end of the cartilage instead of a single central zone. Tissues that were at the three more advanced stages of chondrogenesis when placed in the RWV showed substantial growth, differentiation and mineralization. Mineralization patterns in these older tissues was normal. Tissues at the oldest stage of chondrogenesis showed more growth and as much or more mineralization as tissue cultured only in SCD. These data suggest that exposure to the RWV at early stages of chondrogenesis severely limits the ability for cartilage growth and yields abnormal downstream morphogenesis. However, at later stages of chondrogenesis, the RWV environment may be beneficial and enhance growth and development. Future studies to characterize intercellular signaling molecules and gene expression activities of chondrocytes in the RWV will be valuable for understanding the mechanism of skeletogenesis.

EFFECT OF OESTRADIOL ON CYTOKINE PRODUCTION IN IMMORTALIZED HUMAN MARROW STROMAL CELL LINES

Oestrogen deficiency enhances bone osteoclastogenesis and bone resorption. Evidence of cooperation between stromal cells and osteoclast precursors in mice suggests that oestradiol acts by regulating cytokine release from stromal cells. Bone marrow stroma contains multipotent progenitors that give rise to many mesenchymal lineages, including osteoblasts that may regulate osteoclast differentiation. We immortalized and characterized six human bone marrow stromal cell lines (presence of Stro1, secretion of alkaline phosphatase, osteocalcin, formation of lipid droplets, and presence of α and β oestrogen receptors). The response of cytokines to oestradiol was then evaluated in vitro, as were the phorbol myristate acetate (PMA)-stimulated cytokine levels. Cells had the characteristics of undifferentiated stromal cells (Stro1+, RANK-L+), and expressed α-oestrogen receptors. The osteoblast phenotype (amounts of alkaline phosphatase and osteocalcin) was weak and there was a poor capacity to differentiate into adipocytes. These cell lines did not respond to oestradiol by producing interleukin 6 (IL-6), IL-1 or tumour necrosis factor α (TNF-α) either constitutively or after stimulation with PMA. Moreover, RANK-L and osteoprotegerin expressions were not regulated by oestradiol in vitro. Thus, modulation of these cytokines by stromal cells do not appear to be the mechanism by which oestradiol regulates bone resorption in humans.