Calcium-phosphate-hybridized tendon directly promotes regeneration of tendon-bone insertion

We developed a novel technique to improve tendon-bone attachment by hybridizing calcium phosphate (CaP) with tendons using an alternate soaking process. We characterized the deposited CaP on or in tendons and determined the healing process of anterior cruciate ligament (ACL) grafts by implanting CaP-hybridized free tendons in bone tunnels intra-articularly. Tendons to be implanted were alternately soaked 10 times in a Ca-containing solution and a PO(4)-containing solution for 30 s each. Treated tendons had ash contents threefold that of untreated tendons. Low-crystallinity apatite was found on or in treated tendons. In animal experiments, the CaP-hybridized tendon exhibited osteoclasts at the tendon-bone interface at 5 days after operation. At 2 weeks after operation, there were more osteoclasts and osteoblasts around the tendon than at 5 days after operation. Directly bonded areas were partially found between the implanted tendon and newly formed bone. The formation of a cartilage layer was partially apparent at 3 weeks after operation. The newly formed bone was observed almost around the tendon. We conclude that CaP-hybridized tendons clearly enhance the healing process of ACL grafts at the tendon-bone interface and regenerate a direct insertion-like formation of tendons similar to a normal healthy ACL insertion within 3 weeks after operation.     

Tacrolimus reduces urinary excretion of leukotriene E(4) and inhibits aspirin-induced asthma to threshold dose of aspirin

BACKGROUND: The exact mechanism of aspirin-induced asthma is not clear. It has been postulated that precipitation of asthma attacks by aspirin is linked to inhibition of COX activity and massive release of cysteinyl leukotriene into the airway. Tacrolimus, a macrolide-derived immunosuppressant, is used for immunosuppression in organ transplantation and also for allergic diseases such as atopic dermatitis. OBJECTIVE: We evaluated the effects of tacrolimus in aspirin-induced asthma by using a double-blind, crossover study design. METHODS: Twelve patients with aspirin-induced asthma (male:female, 3:9; mean age +/- SD, 36.7 +/- 7.2 years) received either tacrolimus (0.1 mg/kg) or placebo 2 hours before the threshold dose of oral aspirin. RESULTS: In the placebo arm, oral aspirin significantly decreased FEV 1 concomitant with significant increases in sputum eosinophilic cationic protein and urinary leukotriene E(4) levels. Tacrolimus significantly inhibited bronchoconstriction and abrogated aspirin-induced increase in both sputum eosinophilic cationic protein and urinary leukotriene E(4) levels. CONCLUSION: The current study suggested that tacrolimus inhibited bronchoconstriction to a threshold dose of aspirin by inhibition of cysteinyl leukotriene excretion.     

Astaxanthin limits exercise-induced skeletal and cardiac muscle damage in mice

Dietary antioxidants may attenuate oxidative damage from strenuous exercise in various tissues. Beneficial effects of the antioxidant astaxanthin have been demonstrated in vitro, but not yet in vivo. We investigated the effect of dietary supplementation with astaxanthin on oxidative damage induced by strenuous exercise in mouse gastrocnemius and heart. C57BL/6 mice (7 weeks old) were divided into groups: rested control, intense exercise, and exercise with astaxanthin supplementation. After 3 weeks of exercise acclimation, both exercise groups ran on a treadmill at 28 m/min until exhaustion. Exercise-increased 4-hydroxy-2-nonenal-modified protein and 8-hydroxy-2'-deoxyguanosine in gastrocnemius and heart were blunted in the astaxanthin group. Increases in plasma creatine kinase activity, and in myeloperoxidase activity in gastrocnemius and heart, also were lessened by astaxanthin. Astaxanthin showed accumulation in gastrocnemius and heart from the 3 week supplementation. Astaxanthin can attenuate exercise-induced damage in mouse skeletal muscle and heart, including an associated neutrophil infiltration that induces further damage.     

Generation of B lymphocytes from a single hemopoietic progenitor cell in vitro

The first stages of the pathway by which lymphocytes differentiate from hemopoietic stem cells were studied at a clonal level. When 211 interleukin 3 (IL-3)-induced blast colonies shown to be capable of differentiating into a variety of hemopoietic cells were individually transferred into wells containing a monolayer of stromal cells, growth in granulocyte, macrophage, megakaryocyte, or mast cell lineages was observed in 192 wells. In seven of these 192 wells, lymphoid cell growth also was seen. The lymphoid cells were proved to be B lymphocytes by phenotype and immunoglobulin gene rearrangement analyses and by demonstration of surface expression of IgM. The clonal origin of myeloid and B lymphocyte lineage cells was further confirmed by the generation of both myeloid and B lymphoid cells in the same well following FACS clone-sorting of IL-3 induced blast cells. These results provide in vitro evidence that cells of B lymphoid and myeloid lineage can originate clonally from single primitive hemopoietic stem cells.     

Environmental monitoring and assessment of short-term exposures to hazardous chemicals of a sterilization process in hospital working environments

In order to assess short-term exposures to ethylene oxide, formaldehyde and glutaraldehyde in a sterilization process, the authors conducted continuous environmental monitoring of these chemicals in the breathing zone of workers in 2 hospitals. The arithmetic mean of ethylene oxide was 1.2 ppm near unventilated cabinets housing sterilizing materials, and environmental concentrations of ethylene oxide could not be reduced under threshold limit values time weighted average by only managing general ventilation. Environmental concentration of formaldehyde was lower in a properly ventilated pathology division in which no large specimens were stored (0.3 ppm) than in the pathology division where large specimens were stored (2.3 ppm). Although environmental concentrations of glutaraldehyde in an endoscopy unit with proper general ventilation were not detectable, environmental concentration levels in an endoscopy unit without general ventilation system were 0.2 and 0.5 ppm. According to the results of environmental monitoring in the breathing zone of workers, extremely high concentrations were observed in some work practices (ethylene oxide, 300 ppm; formaldehyde, 8.6 ppm; glutaraldehyde, 2.6 ppm). In order to avoid occupational exposures to these chemicals and prevent potential chronic and acute health hazards, good communications with these chemicals, good work practices, appropriate personal protective equipment, and engineering controls should be required.     

Natural antibodies against the immunoglobulin F(ab′)2 fragment cause elimination of antigens recognized by the F(ab′)2 from the circulation

A humanized monoclonal IgG1 antibody, designated hC4G1, recognizes the fibrinogen receptor glycoprotein (GP)IIb/IIIa on platelets and inhibits platelet aggregation. When the F(ab′)₂ fragment of hC4G1 (F(ab′)₂ hC4G1) was administered to cynomolgus monkeys, all the monkeys showed inhibition of platelet aggregation ex vivo. Unexpectedly, a significant decrease in platelet count was observed in 5 of 18 monkeys. Antibodies against F(ab′)₂ hC4G1 were detected in the plasma of these monkeys by ELISA. Antibody activity in the plasma of these monkeys was significantly correlated with the intensity of platelet decrease (r = 0.84). The natural monkey antibodies to F(ab′)₂ hC4G1 were directed against the C-terminal region of F(ab′)₂ fragment common to all human and humanized IgG antibodies. Natural homo-reactive antibodies were also detected in human plasma from 15 of 40 healthy volunteers. Specificity was closely similar to that of the monkey antibodies. Affinity-purified human homo-reactive antibodies enhanced phagocytosis of platelets treated with the F(ab′)₂ hC4G1. Monkey plasma with high homo-reactive antibody activity was confirmed to decrease platelet count when administered together with F(ab′)₂ hC4G1 to a monkey with low antibody activity. These results suggest that F(ab′)₂ of humanized and human antibodies causes elimination of the corresponding antigens from the circulation by homo-reactive antibodies.     

Copper and iron-induced oxidative damage in non-tumor bearing LEC rats

The copper and Iron status in the liver of non-tumor bearing Long-Evans Cinnamon (LEC) rats (average age 17 months) was investigated. A direct quantitation of loosely-bound copper and iron was also investigated by using a chelating agent, nitrilotriacetic acid (NTA-chelatable free copper and iron). Besides the total copper and iron contents, the level of NTA-chelatable free copper was also higher in LEC rats than In LEA rats (P<0.05). But for the free iron level there was no signiflcant difference between the two rat groups (P>0.05). The formation of thiobarbituric acid-reactive substances was higher In LEC rats than In LEA rats (P<0.01). The 4–hydroxy-2–nonenal (HNE)-modified proteins were also clearly demonstrated in LEC rat liver. The copper and iron which produced the most important effect In the process of oxidative damage in LEC rats could not be distinguished. Even though free copper, which could induce free radical injuries, was increased in LEC rats, neither tumor-induction nor preneo-plastic lesions in the experimental LEC rats were observed. Therefore it is speculated that the elevation of a free iron is another important factor. Copper and iron, both important translation metals In the body, may participate In the Induction of DNA damage and oncogenesls     

Acute effect of inhaled beta(2)-agonists with different type of intrinsic activity on airway resistance in healthy volunteers]

Inhaled beta(2)-agonists (long-acting as well as short acting) are used world-wide for the relief of asthma symptoms. However, there are few reports which have evaluated the additive effect of short-acting beta(2)-agonists to long-acting beta(2)-agonists on airway resistance measured by a plethysmography. This study was designed to evaluate the additive effect of inhaled short-acting beta(2)-agonists (protecarol) to long-acting beta(2)-agonists (salmeterol) on airway resistance in normal healthy volunteers (S+P group). In addition, to compare the effects of beta(2)-agonists which have different types of intrinsic activities, acute effect of inhaled procaterol adding to procaterol was also evaluated (P+P group). Seven healthy volunteers (all male and all non-smokers) were entered in this study. Pulmonary function was measured by a body plethysmography. Forced expiratory volume per 1 second (FEV1), the maximum flow rate at 25% (V(.) 25), the maximum flow rate at 50% of forced vital capacity (V(.) 50), and airway resistance were measured before and after inhalation of salmeterol (1 dry powder, 50 microg) or procaterol (2 puffs, 20 microg). Sixty minutes after inhalation of salmeterol, or 15 minutes after inhalation of procaterol, inhalation of procaterol (2 puffs, 20 microg) was added, and then pulmonary function was monitored. FEV1, V(.) 25, and V(.) 50 were significantly increased after inhalation of salmeterol as well as procaterol. In addition, airway resistance decreased significantly after inhalation of salmeterol as well as procaterol. In the S+P group, additional decrease of airway resistance after inhalation of procaterol was relatively small compared with the P+P group. In conclusion, although additional bronchodilatoric effects were observed in the S+P and P+P group, the effects seemed to be different based on the intrinsic activity of each beta(2)-agonist.     

Leader (L) and L* proteins of Theiler's murine encephalomyelitis virus (TMEV) and their regulation of the virus' biological activities

Theiler's murine encephalomyelitis virus (TMEV) is divided into two subgroups on the basis of their different biological activities. GDVII subgroup strains produce fatal poliomyelitis in mice without virus persistence or demyelination. In contrast, TO subgroup strains induce demyelinating disease with virus persistence in the spinal cords of weanling mice. Two proteins, whose open reading frames are located in the N-terminus of the polyprotein, recently have been reported to be important for TMEV biological activities. One is leader (L) protein and is processed from the most N-terminus of the polyprotein; its function is still unknown. Although the homology of capsid proteins between DA (a representative strain of TO subgroup) and GDVII strains is over 94% at the amino acid level, that of L shows only 85%. Therefore, L is thought to be a key protein for the subgroup-specific biological activities of TMEV. Various studies have demonstrated that L plays important roles in the escape of virus from host immune defenses in the early stage of infection. The second protein is a 17–18 kDa protein, L*, which is synthesized out-of-frame with the polyprotein. Only TO subgroup strains produce L* since GDVII subgroup strains have an ACG rather than AUG at the initiation site and therefore do not synthesize L*. 'Loss and gain of function' experiments demonstrate that L* is essential for virus growth in macrophages, a target cell for TMEV persistence. L* also has been demonstrated to be necessary for TMEV persistence and demyelination. Further analysis of L and L* will help elucidate the pathomechanism(s) of TMEV-induced demyelinating disease.