Biomedical subjects

T Fujinaga

Publications and source records attributed to T Fujinaga.

At least 37 records · Page 2Linked to original sources

PubMed2000

Inhibitory effects of 22-oxa-calcitriol and all- trans retinoic acid on the growth of a canine osteosarcoma derived cell-line in vivo and its pulmonary metastasis in vivo.

Pulmonary metastasis is a major cause of death and a major obstacle to the successful treatment of canine osteosarcoma. However, the residual capacity of the neoplasia for differentiation and its susceptibility to undergo apoptosis may be used to suppress its growth and metastatic properties. The highly metastasizing POS (HMPOS) canine osteosarcoma cell line which preferentially metastasize to the lungs was used to test the possible efficacy of 22-oxa-calcitriol (OCT) and all- trans retinoic acid (ATRA) to inhibit growth and pulmonary metastasis of the subcutaneously grown osteosarcoma in nude mice. Treatments in vitro, morphologically elongated and increased alkaline phosphatase activity and staining of cells. Tumour growth in vivo was inhibited significantly and the combination treatment of OCT and ATRA (OCT + ATRA) exerted a synergistic and stronger suppression at concentration of 1.0 microg kg(-1)body weight when given subcutaneously three times a week for 5 weeks. The subcutaneous tumours of the control mice consisted of osteoblast-like cells and isolated chondroblast-like cells, but formed several areas of osteoid and increased amount of collagen tissue in all treated mice. Pinpoint macrometastatic nodules developed only in all control mice. Micrometastatic nodule developed only in two of six mice treated with ATRA. However, nodule size and number, and lung wet weight were all reduced significantly. Metastasis were not seen in the mice treated with OCT or OCT + ATRA. This study demonstrated that inhibition of growth and pulmonary metastasis was induced by subcutaneous treatment with these drugs and suggest that both its differentiating and apoptotic inducing activities may be responsible for the antitumour effects. These drugs may be useful in the clinic as an adjunct for the treatment of canine osteosarcoma.

Alkaline Phosphatase↗

PubMed2000

Influence of vitamin D and retinoids on the induction of functional differentiation in vitro of canine osteosarcoma clonal cells.

The efficacy of 22-oxacalcitriol (OCT), calcitriol, cholecalciferol, all-trans retinoic acid (ATRA) and 9-cis retinoic acid (9-cis RA) to differentiate in vitro four clonal cells of the canine osteosarcoma cell line POS into cells having properties of a functionally mature osteoblast bone cell were investigated. The induction of intracellular alkaline phosphatase (ALP) activity, osteocalcin (GLA-OC) and type I collagen (PIP) production after 72 h treatment were used as markers of differentiation. At a concentration of 10(-8)M, OCT and calcitriol significantly induced all markers, and ATRA only the ALP of osteoblast, chondroblast and undifferentiated clonal cells. At the same concentration, 9-cis RA and cholecalciferol induced ALP of chondroblast and osteoblast cells, respectively; ATRA, 9-cis RA and cholecalciferol induced PIP of chondroblast and undifferentiated cells. None of the drugs significantly differentiated fibroblast cells. The ability of these agents to differentiate osteosarcoma cells into cells that exhibit properties of functionally mature osteoblastic bone cells may promote normal osteogenesis and reverse the loss of control of their differentiation.

Alkaline Phosphatase↗

PubMed2000

Surgical salvage from comminuted metatarsal fracture using a weight-bearing pin-putty apparatus in a dog.

Comminuted metatarsal fractures in a dog were treated using intramedullary pins externally connected and stabilized by epoxy resin putty and application of a fibreglass cast. Two weeks later the cast was removed. After further 2 weeks application of a Robert-Jones bandage the dog could stand and walk with the pin-putty apparatus in position. The pin-putty apparatus was removed 3 months postoperatively, and the dog resumed normal activity. This fixation method could be an easy, economical and effective alternative treatment for managing comminuted fractures of the metatarsal and possibly metacarpal bones in selected cases.

Animals↗

PubMed2000

Consideration of the role of antigenic keratan sulphate reacting to a 1/14/16H9 antibody as a molecular marker to monitor cartilage metabolism in horses.

The role of keratan sulphate (KS) as a marker of cartilage metabolism was evaluated by using an in vitro model of equine articular cartilage. Articular cartilage was harvested from clinically healthy 6-month-old foals (n=3). Chondrocytes were centrifuged and cultured as pellets. Chondrocyte pellets were stimulated by insulin-like growth factor (IGF)-Ialpha or interleukin (IL)-1alpha for 2 weeks. The sulfated glycosaminoglycans (GAG) and antigenic KS concentrations in the culture media were measured by a 1,9-dimethyl-methylene blue (DMMB) colorimetric assay and an inhibition ELISA using a 1/14/16H9 antibody, respectively. Concentration of GAG was significantly increased in the media of pellets stimulated by both IGF-Ialpha and IL-1alpha. Antigenic KS concentration was significantly increased in those stimulated by IL-1alpha, while no significant change was found in those stimulated by IGF-Ialpha. A high correlation between GAG and antigenic KS concentrations was found in the media of pellets stimulated by IL-1alpha (r=0.87), but not in those stimulated by IGF-Ialpha (r=0.43). The results suggest that the concentration of antigenic KS reacting to 1/14/16H9 mirrors the GAG concentration during the stage of cartilage catabolism, but not during the cartilage anabolic stage. The concentration of antigenic KS reacting to 1/14/16H9 antibody in biological fluids could therefore be a useful marker to further understand principally the catabolic and slightly the anabolic process of articular cartilage metabolism.

Animals↗

PubMed1999

Physiological production of singlet molecular oxygen in the myeloperoxidase-H2O2-chloride system.

The putative role of singlet oxygen (1O2) in the respiratory burst of neutrophils has remained elusive due to the lack of reliable means to study its quantitative production. To measure 1O2 directly from biological or chemical reactions in the near infrared region, we have developed a highly sensitive detection system which employs two InGaAs/InP pin photodiodes incorporated with a dual charge integrating amplifier circuit. Using this detection system, we detected light emission derived from a myeloperoxidase (MPO)-mediated reaction in physiological conditions: pH 7.4, 1-30 nM MPO, 10-100 microM H2O2 and 100-130 mM CI in place of Br without the use of deuterium oxide. The MNPO-H2O2-CI(-) system exhibited a single emission peak at 1.27 microm with a spectral distribution identical to that of delta singlet oxygen. Our results suggest physiological production of 1O2 in the MPO-H2O2-CI(-) system at an intravacuolar neutral pH. The MPO-mediated generation of 1O2, which may have an important role in host defense mechanisms, is discussed in connection with previous results.

Animals↗

PubMed1999

Accelerating effects of chitosan for healing at early phase of experimental open wound in dogs.

Chitosan is a polymeric beta(1 --> 4) glucosamine (2-amino-2-deoxy-D-glucose) and N-acetyl-D-glucosamine (2-acetamido-2-deoxy-D-glucose) which has been reported as a wound healing accelerator. In order to evaluate the efficacy of chitosan as an accelerator of wound healing, experimental open skin wounds were made on the dorsal side in three normal beagles. Cottonfiber-type chitosan (degree of acetylation = 18%) was applied for 15 days, and the process of wound healing was evaluated histologically and immunohistochemically. On day 3 postwounding, the chitosan-treated wounds showed histologically severe infiltration of polymorphonuclear (PMN) cells and an increase in effusion compared with that in the control. Granulation was more pronounced by the chitosan treatment on day 9 and 15 postwounding. Immunohistochemical typing of collagen I, III and IV showed increase of the production of type III collagen in the chitosan group. The appearance of mitotic cells occurred numerously in the control on postwounding day 3, and in the chitosan group on postwounding day 6. These results suggest chitosan to be having a function in the acceleration of infiltration of PMN cells at the early stage of wound healing, followed by the production of collagen by fibroblasts.

Animals↗

PubMed1999

Induction of functional differentiation and growth inhibition in vitro of canine osteosarcoma by 22-oxacalcitriol, calcitriol and all-trans retinoic acid.

The effects of 22-oxacalcitriol (OCT), calcitriol and all-trans retinoic acid (ATRA) on the induction of functional differentiation and growth inhibition of the canine osteosarcoma cell line POS were investigated in vitro via bone differentiation markers and proliferation assays, respectively. The intracellular alkaline phosphatase (ALP) activity and the gamma-carboxyglutamic acid osteocalcin (GLA-OC) and procollagen type I C peptide (PIP) production were used as markers of differentiation. Treatment with 10(-8) M concentrations of all drugs for 72 h significantly inhibited growth (P < 0.0001) and increased ALP activity and GLA-OC and PIP production in POS. OCT, calcitriol and ATRA significantly increased the: ALP activity from 1.58 +/- 0.14 mumol/min/mg protein (mean +/- SD; control) to 2.50 +/- 0.09 (P < 0.0001), 2.30 +/- 0.14 (P < 0.0001) and 2.00 +/- 0.14 (P = 0.0008), respectively; GLA-OC production from 0.71 +/- 0.01 ng/ml (control) to 2.87 +/- 0.01 (P < 0.0001), 2.87 +/- 0.11 (P < 0.0001) and 1.36 +/- 0.06 (P < 0.0001), respectively; and PIP production from 433.91 +/- 23.29 ng/ml (control) to 536.54 +/- 15.46 (P = 0.0002), 497.06 +/- 1.99 (P = 0.0028) and 481.66 +/- 0.01 (P = 0.0104), respectively. This study demonstrated that treatment with these drugs induced a phenotypic maturation of POS cells into cells that exhibit the properties of functionally mature bone cells with parallel growth inhibition. The effects of these drugs on functional differentiation may be useful to complement the progression of a normal osteogenic differentiation process in the sarcoma.

Alkaline Phosphatase↗

PubMed1999

Post-traumatic high flow priapism: a case report.

A case of post-traumatic high flow priapism in a 32-year-old man is reported. The diagnosis was based on cavernous blood gas analysis and left internal pudendal arteriography. He was treated by unilateral super-selective embolization of the fistula with coils and gelatin sponge. At 1 month after embolization, erectile function had recovered, as demonstrated by measurement of nocturnal penile tumescence.

Adult↗

PubMed1999

Effects of vitamin D and retinoids on the differentiation and growth in vitro of canine osteosarcoma and its clonal cell lines.

Although canine osteosarcoma is one of the most malignant, aggressive and lethal neoplasms originating from undifferentiated bone cells, it may retain some capacity for normal differentiation. The purpose of this study was to ascertain if the residual capacity for differentiation could be used to suppress its malignant properties. We tested the efficacy of vitamin D and retinoids in inducing differentiation and inhibiting growth of the POS canine osteosarcoma and four of its clonal cell lines, POS 14A (fibroblast type), POS 53B (chondroblast type), POS 53C (undifferentiated type) and POS 53D (osteoblastic type). Treatment with 10(-10)to 10(-8)M concentrations of calcitriol, OCT, cholecalciferol, all-trans retinoic acid (ATRA) and 9-cis retinoic acid for 48-120 hours changed the morphology of POS, POS 53B, POS 53C and POS 53D cells to cells that were elongated and spindle-shaped. Increased number of cytoplasmic organelles and pronounced nuclear activities were induced by concentrations of 10(-8)M and 10(-7)M for 120 hours. All drugs at concentrations of 10(-10)to 10(-8)M for 72 hours inhibited POS growth dose-dependently. OCT significantly reduced the cell number in all cell lines when used at concentrations between 10(-9)and 10(-8)M for 72 hours and exerted significant anti-proliferative effects for eight days culture. This study demonstrated that changed morphology and inhibition of growth was induced by treatment of the cells with these vitamins, that the loss of control of differentiation in the neoplasia was not irreversible and that these drugs may be useful in the clinic.

Animals↗

PubMed1999

Surgical correction of temporomandibular joint ankylosis in two cats.

Two cats with temporomandibular joint ankylosis were examined. Difficulty in opening the mouth and malocclusion were associated with trauma and fracture around the zygomatic arch and the condyle of the mandible after an automobile accident. Unilateral condylectomy or aggressive caudal mandibulectomy was performed to improve quality of life. Excision arthroplasty of the temporomandibular joint improved mandibular function and appearance. Some malocclusion remained but had no clinical significance.

Accidents, Traffic↗

PubMed1999

Establishment and characterization of the growth and pulmonary metastasis of a highly lung metastasizing cell line from canine osteosarcoma in nude mice.

Highly lung metastasizing model of canine osteosarcoma in nude mice was established from five subcutaneous implantation cycles of lung tumor deposits. The selection of cells with increased metastatic properties from the parent POS canine osteosarcoma cell line recovered medium sized and polygonal Highly Metastasizing POS cells (HMPOS). The doubling time of HMPOS and POS in culture averaged 30 +/- 1.2 hr and 32 +/- 1.3 hr respectively, and their cell growth patterns in vitro were comparable to their in vivo growth patterns. HMPOS cells produced more tumor deposits (> 20 nodules, > 1 -mm in diameter) of various sizes with replacement of lung tissues at 12 weeks after implantation. POS cells produced fewer and smaller lung deposits (< 10 nodules, 1-mm in diameter). Tumor size and number of metastatic tumor deposits showed a regular association. HMPOS cells developed an osteoblastic type of cellular differentiation subcutaneously and in the lungs. HMPOS micrometastasis along the alveolar walls and blood vessels at 4 weeks averaged 6-7 small tumor locus. Each micrometastatic locus contained an average of 5-7 tumor cells, and developed a pleomorphic osteoblastic type of cellular differentiation. An average of 4 macrometastatic nodules could be seen at 6 weeks, composed of an average of 23 tumor cells, 10 nodules at 8 weeks, 12 nodules at 10 weeks and 20 nodules at 12 weeks. These model provides an opportunity for the evaluation of new treatments against canine lung metastatic osteosarcoma in a nude mice model.

Animals↗

PubMed1999

Plasma atrial and brain natriuretic peptide levels in dogs with congestive heart failure.

Plasma concentrations of atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP) were measured in 6 dogs with experimental mitral regurgitation (MR) and 19 canine patients with asymptomatic and symptomatic congestive heart failure (CHF). In dogs with experimental MR, ANP and BNP concentrations were significantly correlated with pulmonary capillary wedge pressure (PCWP) (ANP; r=0.852, P=0.0004, BNP; r=0.832, P=0.0008). ANP level was shown to have a predominant effect on PCWP in comparison with BNP using multiple regression analysis. In canine patients with asymptomatic and symptomatic CHF, ANP and BNP concentrations were significantly different among the heart failure classes according to the New York Heart Association functional classification (ANP; P=0.0165, BNP; P=0.0005). In addition, ANP and BNP levels in dogs with decompensated heart failure (n=10) significantly increased in comparison with those in dogs with compensated heart failure (n=9). There was however no correlation between ANP and BNP levels in each heart failure class. In conclusion, plasma ANP and BNP levels may become predictors of PCWP and the severity of heart failure in dogs with MR, although further investigations on ANP and BNP levels in more clinical cases are required.

Animals↗

PubMed1999

Peri-operative changes in echocardiographic measurements and plasma atrial and brain natriuretic peptide concentrations in 3 dogs with patent ductus arteriosus.

Peri-operative changes in echocardiographic measurements and plasma levels of atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP) were investigated for 1 month in 3 dogs with patent ductus arteriosus (PDA). Post-operative left ventricular end-diastolic dimention and fractional shortening decreased in all cases. Pre-operatively increased plasma ANP concentrations reduced dramatically after the operation. Peri-operative changes in plasma BNP levels had slightly S-shaped curves in all cases. These observations suggest that post-operative responsiveness of ANP and cardiac function are rapid in comparison with cardiac morphological changes, and BNP has a different pathophysiological significance from ANP in dogs with PDA.

Animals↗

PubMed1999

Complementary DNA cloning, tissue distribution, and synthesis of canine brain natriuretic peptide.

OBJECTIVE: To determine complimentary DNA (cDNA) sequence and tissue distribution of canine brain natriuretic peptide (BNP), and to investigate whether synthesis of canine BNP increases in association with cardiovascular dysfunction. ANIMALS: 5 healthy adult mixed-breed dogs and 3 healthy adult Beagles. PROCEDURE: Total RNA was extracted from normal canine hearts and was used in a reverse transcription-polymerase chain reaction (RT-PCR) procedure to isolate canine BNP cDNA. Sequence of the isolated cDNA was analyzed. Gene expression of canine BNP in various tissues from 2 mixed-breed dogs was investigated, using RT-PCR and northern blot analyses. Moreover, messenger RNA (mRNA) expression of canine BNP, using northern blot analysis, was compared between grossly normal hearts from 3 Beagles and hearts from 3 mixed-breed dogs with acute myocardial infarction created by surgical ligation. RESULTS: The cDNA sequence and deduced amino acid residues of canine BNP precursor were 420 base pairs and 140 residues, respectively. Messenger RNA expression of canine BNP was detectable in the atria but not in the ventricles and the other tissues. Messenger RNA expression of canine BNP was, however, detectable in the infarcted portion of the ventricles. The amount of canine BNP mRNA in the infarcted ventricles was significantly increased, compared with that of noninfarcted ventricles. CONCLUSION: The cDNA sequence of canine BNP was determined. Expression of canine BNP mRNA was detected not only in the atria but also in infarcted ventricles. Synthesis of canine BNP increases in association with ischemic myocardial injury. Canine BNP may be used as an indicator of severity of ventricular myocardial injury.

Amino Acid Sequence↗

PubMed1998

Endothelial cell responses to chitin and its derivatives.

The effects of chitin and its derivatives on the proliferation of human umbilical vein endothelial cells (HUVECs) and on the production of cytokines were examined in vitro. Chitin and its derivatives had no effect on the proliferation of cultured HUVECs. N-Sulfonated 70% deacetylated chitin (S-DAC70) stimulated the production of interleukin (IL)-1beta, IL-6, IL-8, and tumor necrosis factor (TNF)-alpha from HUVECs. Compared to S-DAC70, the other materials tested in the present study showed less effect in the stimulation of IL-8 and TNF-alpha production and had no effect in the stimulation of IL-1beta and IL-6 production. These results indicated that S-DAC70 affects HUVECs function but not proliferation.

Biocompatible Materials↗

PubMed1998

Relationship between glutathione S-transferase M1 deficiency and urothelial cancer in dye workers exposed to aromatic amines.

PURPOSE: It is speculated that the susceptibility to urothelial cancer in dye workers who are exposed to aromatic amines is affected not only by occupational environmental factors but by host specific factors. We evaluated the interaction between glutathione S-transferase M1 gene deficiency and the occupational environmental factors associated with urothelial cancer. MATERIALS AND METHODS: The study included 137 workers who had prior exposure to dyestuff intermediates, of whom 36 had urothelial cancer. The prevalence of a glutathione S-transferase M1 gene polymorphism was investigated using polymerase chain reaction. The relationship between the glutathione S-transferase M1 0/0 gene and occupational environmental factors in the onset of urothelial cancer was examined by multivariate analysis. RESULTS: The prevalence of glutathione S-transferase M1 gene deficiency did not differ significantly between the urothelial cancer (21 cases, 58.3%) group and the cancer-free (47, 46.3%) group. It was estimated that 29.6% of the urothelial cancers in these dye workers was attributable to the glutathione S-transferase M1 0/0 gene. Analysis using multiple logistic models showed low predictive ability for urothelial cancer due to glutathione S-transferase M1 gene deficiency (p = 0.084, odds ratio 2.260, 95% confidence interval [CI] 0.904 to 5.652). A history of working in small factories (p = 0.000, odds ratio 7.404, 95% CI 2.854 to 19.206) and a long period of exposure (p = 0.016, odds ratio 5.051, 95% CI 1.371 to 18.612) significantly predicted cancer. CONCLUSIONS: We demonstrated a strong trend using the multiple logistic analysis of the contribution of glutathione S-transferase M1 gene polymorphism and occupational environmental factors. Therefore, the glutathione S-transferase M1 enzyme might have an important role in the detoxification of aromatic amine derived carcinogens. Occupational environmental factors, however, might contribute more than a glutathione S-transferase M1 gene deficiency to the occurrence of urothelial cancer among individuals exposed to aromatic amines, because of the extremely potent carcinogenicity of some occupational environmental factors.

2-Naphthylamine↗

PubMed1998

Measurement of serum and synovial fluid keratan sulphate and antibody to collagen type II in equine osteoarthritis.

Keratan sulphate (KS) concentration and anticollagen type II antibody levels were measured in the serum and synovial fluid (SF) of clinically normal horses and horses with osteoarthritis (OA). Serum KS in OA was significantly higher than that in normal horses, while no significant difference was found in KS levels of SF between normal and OA. Assays of antibody to collagen type II showed no significant increase in sera and SF of OA. It was suggested that levels of serum KS would be of value in the pathological detection of OA in the joint, although there was no evidence that the measurable autoimmunity to collagen antigens would reflect the process of OA.

Animals↗

PubMed1998

Spectrophotometric determination of neutrophil cytochrome b558 of chronic granulomatous disease.

BACKGROUND: Chronic granulomatous disease (CGD) is an inherited disease characterized clinically by severe recurrent bacterial infections from infancy. This disease is a disorder of the formation of superoxide (O2-) by the neutrophil NADPH oxidase system, mostly due to defects in cytochrome b558 (cyt b558), which is one of the oxidase components. Diagnosis of CGD has been performed by the assay of the O2- forming activity, immunological determination of defects in the oxidase components, and or spectrophotometry of cyt b558. However, spectrophotometric analysis of the b-type heme is difficult with small amounts of blood from infant CGD patients, as the limited amounts of neutrophils are contaminated with a relatively high ratio of hemoglobin (Hb) that interferes with the heme spectrum of cyt b558. This report presents an accurate method for the spectrophotometric analysis of cyt b558 in a small amount of CGD neutrophils that were treated with CO gas in a safe procedure instead of the previously reported CO-bubbling method. METHODS AND RESULTS: The difference of the reduced minus oxidized cyt b558 spectrum was measured under no interference from oxy Hb at the alpha and beta bands and differentiated as d[delta A]/d lambda (lambda = wavelength) to obtain further evidence for the defects of the cyt b558 heme spectrum. The interference from CO-insensitive met Hb was eliminated by subtracting the absorption peak at the Soret (gamma) band of the contaminating met Hb, which was estimated from the CO-treated and untreated spectra of the same, hemolyzed sample. CONCLUSIONS: This spectrophotometric method is feasible for the determination of abnormality and heme content of cyt b558 with a small amount of CGD neutrophils in 10-20 mL of blood even in the presence of contaminating Hb.

Cytochrome b Group↗