Ascorbic acid is essential to the biosynthesis of collagen, the major organic matrix component of dentine. The ODS rat is a mutant strain of Wistar rat characterized by hereditary lack of L-gulono-gamma-lactone oxidase and thus is unable to synthesize ascorbic acid. ODS rats were given an ascorbic acid-free diet to investigate how ascorbic acid deficiency affects dentine formation in vivo. Histomorphometric analysis on their growing molars and incisors showed a significant reduction in both size and mineral apposition rate of dentine, as revealed by contact microradiography and fluorescent time-marking, respectively. A similar reduction in bone formation was simultaneously demonstrated in the mandible, confirming the previously reported osteopathic effects of ascorbic acid deficiency. When pulp inflammation was induced in lower first molars by making unsealed pulp exposures, specimens from control animals showed continuous deposition of an osteodentine-like tissue in the radicular pulp chamber; this type of mineralized tissue formation was greatly reduced in ascorbic acid-deprived animals. These results indicate that ascorbic acid deficiency hampers dentine formation under both physiological and pathological conditions of the dentine/pulp complex. ODS rats could be useful in investigating in vivo effects of ascorbic acid deficiency on the formation of dentine and other dental mineralized tissues.

Animals↗

PubMedDate not supplied

Legg-Calvé-Perthes disease in the evolutionary period: comparison of magnetic resonance imaging with bone scintigraphy.

Magnetic resonance images (MRIs) and pinhole scintigraphs were obtained in 40 patients (40 hips) with Legg-Calvé-Perthes disease in the evolutionary phase, the mean age at onset of symptoms being 6 years 7 months. The correlation between the uptake of the pinhole scintigraphs and the signal intensity of MRIs was examined in reference to the extent of the involved femoral epiphysis. MRIs depicted the extent of the involved femoral epiphysis more clearly than did pinhole scintigraphs. The uptakes of the pinhole scintigraphs corresponded with high or normal intensity of T2-weighted images on MRI. The femoral epiphysis in the initial phase (in which the signal intensity of the lateral area of the epiphysis on T1-weighted coronal images was low or intermediate and high or unchanged on T2-weighted coronal images corresponded to the lateral column [recanalization] on the pinhole scintigraphs) suggested a low risk of subsequent deformity. MRI is a powerful new technique to evaluate the femoral epiphysis in Legg-Calvé-Perthes disease.

Adolescent↗

PubMedDate not supplied

Anti-allergic effects of ketanserin on animal models of allergic reactions.

The aim of the present study is to investigate the effect of ketanserin, a potent and selective S2-serotonergic antagonist, on some anaphylactic reactions in mice, rats and guinea-pigs. Ketanserin (1 and 5 mg/kg) inhibited both IgE antibody-mediated 48 hr homologous passive cutaneous anaphylaxis and IgG antibody-mediated 1.5 hr homologous passive cutaneous anaphylaxis in mice. In histamine-, serotonin- and LTC4-induced skin reactions in mice, ketanserin inhibited an increase of capillary permeability caused by each mediator. Cyproheptadine, at doses of 0.1 and 0.5 mg/kg, inhibits 48 hr and 1.5 hr homologous passive cutaneous anaphylaxis and histamine-induced capillary permeability increase in mice ear. The inhibitory activity of cyproheptadine on these reactions is more potent than that of ketanserin. However, ketanserin showed a more potent inhibition than cyproheptadine for serotonin-induced capillary permeability. In rat passive peritoneal anaphylaxis, ketanserin had little effect on the release of histamine from peritoneal mast cells. Ketanserin inhibited an antigen-induced contraction of the sensitized guinea-pig trachea at an early period (within 5 min after treatment with antigen) but not at a late period (between 5 to 15 min). Cyproheptadine had little effect on this antigen-induced contraction of sensitized guinea-pig trachea. Moreover, ketanserin inhibited both histamine- and serotonin-induced contractions of the guinea-pig trachea, but not the contraction caused by carbachol and LTC4. When Forssman antibody was injected into the guinea-pigs, a biphasic increase of airway resistance was observed. Ketanserin inhibited an increase of airway resistance at late phases. These results suggest that ketanserin inhibited some anaphylactic reactions in mice and guinea-pigs probably due to the antagonistic action of histamine and serotonin.

Airway Resistance↗

PubMedDate not supplied

Surgical treatment of isolated iliac artery aneurysm with ureteral obstruction and/or renal failure.

Three patients with isolated iliac artery aneurysm with ureteral obstruction and/or renal failure are presented. One patient had a stenotic lesion of the right ureter caused by direct compression of common and internal iliac artery aneurysms. Resection of the aneurysms and graft replacement were successfully performed. The other patients, who had hydroureteronephrosis and renal failure caused by entrapment of the ureters in perianeurysmal fibrosis, were treated surgically by ureterolysis, resection with graft replacement of the common iliac artery aneurysms, and endoaneurysmorraphy of the internal iliac artery aneurysms. One has had a good postoperative course, whereas the other died from a rare complication of rectosigmoid colon perforation caused by direct compression by the graft.

Acute Kidney Injury↗