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Biomedical subjects

T Iizuka

Publications and source records attributed to T Iizuka.

At least 127 records · Page 7Linked to original sources
PubMed1998

Outcome of arthroscopic surgery to the temporomandibular joint correlates with stage of internal derangement: five-year follow-up study.

We studied the 5-year long-term outcome of arthroscopic surgery, and also investigated whether outcome correlates with stage of internal derangement of the temporomandibular joint (TMJ). A consecutive group of 41 patients (56 joints) who had been followed up for between 3 and 5 years were involved in this study. The result was excellent in 22 patients (54%) and fair in 15 (37%). 7/14 were excellent and 5/14 were fair in stage III, 7/12 were excellent and 4/12 were fair in stage IV, and 8/15 were excellent and 6/15 were fair in stage V. Arthroscopic surgery of the TMJ is an effective and minimally invasive technique for various stages of internal derangement.

Activities of Daily Living↗
PubMed1998

Open reduction without fixation of dislocated condylar process fractures: long-term clinical and radiologic analysis.

PURPOSE: This study evaluates the long-term results of open reduction without fixation for displaced fractures of the condylar process. PATIENTS AND METHODS: Clinical and radiologic examinations were performed on 27 patients with 29 operated joints an average of 6.7 years postoperatively. The postoperative result was evaluated on the basis of occlusal and joint function, as well as radiographic assessment of condylar changes. RESULTS: Clinically, satisfactory results were achieved. Radiologically, despite correct intraoperative alignment of the fractured segments, a slight medial deviation of the condylar process was found on the posteroanterior radiograph. However, in only two cases was a 20-degree deviation observed. On final follow-up, 48% of the cases had a normal condylar configuration radiologically, and in the remaining cases, normal function was established even though there were condylar changes. Fully exposed and devascularized condylar processes generally showed more severe changes than those in which partial vascularization was maintained. CONCLUSION: The surgical management described enables a satisfactory outcome to be achieved with dislocated condylar process fractures.

Adolescent↗
PubMed1998

Skeletal stability following mandibular advancement and rigid fixation with polylactide biodegradable screws.

Skeletal stability during the first year after mandibular advancement surgery and fixation using biodegradable self-reinforced poly-l-lactide (SR-PLLA) screws, without postoperative intermaxillary fixation, was studied in 25 patients by means of cephalometric measurements. The magnitude of advancement was on average, 3.88 mm at pogonion (PG) (range 1.25-6.5 mm) and 4.57 mm at B-point (range 2.75-7.5 mm). After one year a mean relapse backwards of 0.59 mm at the PG (15%) and 0.78 mm at the B-point (17%) was observed. Nineteen patients (76%) and 17 patients (68%) were stable at PG and B-point, respectively. SR-PLLA screws are considered to be comparable to other forms of rigid internal fixation for fixation of bilateral splitting osteotomies after mandibular advancement, as far as skeletal stability is concerned.

Absorption↗
PubMed1998

Osteoinduction capability of recombinant human bone morphogenetic protein-2 in intramuscular and subcutaneous sites: an experimental study.

The osteoinduction capability of recombinant human bone morphogenetic protein-2 (rhBMP-2) in the muscle and in the subcutaneous tissue in Wistar rats (n = 20) was evaluated, using atelopeptide type-I collagen as a carrier. The alkaline phosphatase (ALP) activity and calcium (Ca) content were quantitatively analyzed 1, 3, 7 and 21 days after the implantation of 5 micrograms of rhBMP-2. At 3 days, the ALP activity began to increase gradually. The Ca content showed a slow increase until 7 days and was markedly elevated at 21 days. There was no significant difference observed between the intramuscular and subcutaneous sites until 3 days. However, at 7 days, both the ALP activity and Ca content were significantly higher intramuscularly than subcutaneously. Also, at 21 days they were higher in the muscle than in the subcutaneous tissue. These results suggest that the difference in osteoinduction could be related to the partial pressure of oxygen or the blood supply in the intramuscular and subcutaneous sites, and that immature mesenchymal cells in the muscle could more easily differentiate into osteoblasts, leading to osteoinduction. This study clearly demonstrated that even a small amount (5 micrograms) or rhBMP-2 induces new bone in the subcutaneous tissue, which has a lesser blood flow than the muscle.

Alkaline Phosphatase↗
PubMed1998

Effectiveness of kampo medicine (sai-boku-to) in treatment of patients with glossodynia.

OBJECTIVE: The purpose of this study was to evaluate the usefulness of a Kampo medicine (Sai-boku-to) for treatment of patients with glossodynia. STUDY DESIGN: Sai-boku-to or an antianxiety drug (diazepam) with vitamin B complex was administered orally for 3 months to each of 200 patients with glossodynia. Clinical examination evaluated the following subjective symptoms: pain, burning sensation, and discomfort. Effectiveness was evaluated as follows: "markedly effective," all 3 symptoms disappeared; "effective," pain improved; "ineffective," no improvement in pain. RESULTS: The effective rates were 70% after 1 month, 85% after 2 months, and 92% after 3 months of administration of Sai-boku-to (the Kampo group) and 74% after 1 month, 71% after 2 months, and 69% after 3 months of administration of the antianxiety drug with vitamin B complex (the control group). No significant side effect was noted in the Kampo group, but sleepiness was recorded in 33 cases in the control group. CONCLUSIONS: The results indicate that Sai-boku-to may be a clinically useful medicine for the long-term treatment of patients with glossodynia.

Adult↗
PubMed1998

Radiologic changes of the temporomandibular joint after condylar fractures in childhood.

OBJECTIVE: The purpose of this investigation was to study the radiologic outcomes of pediatric condylar fractures. STUDY DESIGN: Radiographs of 37 patients with 45 condylar fractures that had been diagnosed at the Department of Oral and Maxillofacial Surgery, Helsinki University Central Hospital were retrospectively reviewed. The frequency and characteristics of incomplete remodeling at an average of 4.1 years after the injury were studied. The influence of age and fracture type on remodeling were considered. RESULTS: Incomplete remodeling was observed after 56% of the fractures. The most frequent signs of incomplete remodeling were alteration in the configuration of the surface of the condylar head and deformation of the condylar neck. Incomplete remodeling was frequently (83%) related to fracture dislocation. For this fracture type the radiologic prognosis seems poor in all age groups. A difference in ramus height between the 2 sides was observed in 52% of the fractures, particularly frequently (80%) after fracture dislocation. CONCLUSIONS: Radiologic aberrations are frequent after pediatric condylar fractures. Dislocated fractures, in particular, need special attention and long-lasting clinical follow-up.

Adolescent↗
PubMed1998

Prefabricated muscle flap including bone induced by recombinant human bone morphogenetic protein-2: an experimental study of ectopic osteoinduction in a rat latissimus dorsi muscle flap.

For skeletal reconstruction, a vascularised bone graft is both reliable and useful, but some sacrifice usually occurs at the skeletal donor site. In the search for our alternative, we investigated ectopic osteoinduction by bone morphogenetic protein in a rat muscle flap, to prefabricate a muscle flap that included bone. Right latissimus dorsi muscle flaps were prepared in 16 rats. Recombinant human bone morphogenetic protein-2 (rhBMP-2; 2, 10 and 50 micrograms) mixed with atelopeptide type I collagen (3 mg) as the carrier was wrapped with the tip of the latissimus dorsi muscle flap. Three weeks later, ectopic osteoinduction in the latissimus dorsi muscle flap was investigated radiologically, histologically and biochemically. A radiological oval shadow was observed in each animal in each rhBMP-2-implanted group. The volume of the oval shadow area in the muscle flap was dependent upon the dosage of rhBMP-2. It indicated that on ectopic osteoinduction by rhBMP-2 in the muscle flap, induced trabeculae were circularly constructed at the margins of the lump. The radio-opacity of the oval shadows was almost equal in all rhBMP-2-implanted groups, and the shadow areas depended on the dosage of rhBMP-2. The biochemical indices of osteogenesis, ALP activity and Ca content in the lump were dependent upon the dosage of rhBMP-2. This study showed that ectopic osteoinduction occurred in the rat latissimus dorsi muscle flap and depended upon the dose of rhBMP-2. Wrapping rhBMP-2 mixed with atelopeptide type I collagen with the tip of a latissimus dorsi muscle flap could create a prefabricated muscle flap that included bone.

Animals↗
PubMed1998

The presence of nitric oxide synthase in the mammary glands of lactating rats.

Our objective was to show the presence of nitric oxide synthase (NOS) in the mammary glands of lactating rats and to determine the role that nitric oxide plays in lactation of humans. We used the nicotinamide adenine dinucleotide phosphate (NADPH) diaphorase reaction and immunostaining on fresh frozen breast tissue obtained from lactating Wistar rats (13-18 wk old, 320-380 g, 3-4 d after parturition, first pregnancy). The breast tissues positive for NADPH diaphorase staining were the mammary gland, muscle, sebaceous gland, epidermis, and endothelium of the lactiferous ducts and blood vessels. These findings corresponded to tissues that were NOS-immunoreactive. The NOS detected in the mammary glands was the constitutive NOS. The finding of positive anti-NOS immunoreactivity and of positive NADPH diaphorase activity in the cells of the rat mammary glands leads us to conclude that nitric oxide is synthesized in mammary glands of rats. The high nitric oxide activity in the human breast was previously reported by measuring the total concentration of nitrite plus nitrate, biopterin, and neopterin in human milk. These results suggest that nitric oxide plays a role in the secretion of human breast milk.

Animals↗
PubMed1998

Redistribution in thallium-201 myocardial imaging soon after successful coronary stenting--tomographic evaluation during coronary hyperemia induced by adenosine.

To evaluate the clinical significance of reversible perfusion defects that were observed soon after the successful deployment of a coronary stent, 47 patients underwent thallium-201 myocardial scintigraphy and radionuclide angiography in conjunction with adenosine-induced coronary hyperemia before and after complete revascularization. Coronary angiography showed a significant decrease in the percent diameter stenosis (from 87+/-11% before stenting to -1+/-5% after stenting, p<0.01) with no major dissection, residual stenosis, or intra-stent formation of thrombus. Even after the angiographically successful procedure, reversible perfusion defects were present in 17 (36%) of the 47 patients, none of whom showed any wall motion abnormalities during the infusion of adenosine. Disease duration was significantly longer and collateral vessels were more common in the patients with than in those without thallium redistribution, whereas the other clinical, pre- and post-stent angiographic and hemodynamic factors were similar. In conclusion, reversible perfusion defects without wall motion abnormalities were demonstrated during the infusion of adenosine in approximately one-third of patients soon after coronary stenting, and were not consistently related to acute unfavorable outcomes of stent placement.

Adenosine↗
PubMed1998

Quick responses of plasma amino acid concentration to changes in dietary amino acid levels in rats.

In order to evaluate the availability of plasma amino acid (AA) concentration as a parameter to determine AA requirements of rats within a short period, the response of the plasma AA concentration to changes in dietary AA levels was studied. In Experiment 1, to clarify whether the plasma AA concentration responded to changes in dietary AA levels and how long the response of the plasma AA concentration was maintained, 10 male rats were fed a casein diet for a 7 day period, and then the food was changed to AA diets. The serine (Ser), glycine (Gly) and threonine (Thr) levels were decreased from 120, 90 to 60% of the casein diet at 7-day intervals successively. Blood samples were taken at 2, 4 and 7 days after changing the diet, from the vena caudalis by vein puncture. In all cases, the plasma AA concentration responded to changes in dietary AA within 2 days, and the response was maintained until the 7th day. Experiment 2 was conducted to confirm that the plasma concentration of each AA responded to the changes in dietary AA levels at the first day and the responses of the plasma concentration of AA were maintained until the 4th day after changing the dietary AA levels, when the combination of metabolically unrelated AA was added. Five rats in A groups were fed diets with added arginine + Thr, histidine + methionine, lysine or isoleucine + Ser, and five rats in B groups were fed diets with added Gly + valine, leucine + phenylalanine or Thr + tyrosine + valine for a 4-day period successively. Blood samples were taken at 1 and 4 days after changing diets. Although the plasma concentrations of histidine, leucine, methionine, phenylalanine and Ser did not respond to changes in dietary AA levels, those of other AA responded at 1 day and the responses were maintained until the 4th day.

Amino Acids, Essential↗
PubMed1998

[Two cases of dermatophytosis of the external auditory meatus].

We report two cases of dermatophytosis of the external auditory meatus. Case 1: A 44-year-old man suffered from severe itching in the right external auditory meatus for a year, and had also had tinea unguium for several years. He visited our outpatient clinic because of scaly erythema which had developed on the auricle. Otoscopic examination revealed yellow-brown dry cerumen and redness from the cartilaginous to the bony portion of the external auditory meatus. Case 2: A 14-year-old boy, the son of Case 1, suffered from severe itching in the left external auditory meatus. He scratched the auditory meatus with an earpick which his father had used. Otoscopic examination revealed a similar lesion as in the father's case, although he had no history of dermatophytosis elsewhere on his body, including the auricle. Direct examination using a KOH method of the cerumen from both cases demonstrated numerous fungal elements. Fungal culture identified Trichophyton rubrum. Both cases were successfully treated with oral itraconazole. We suggest that infection from father to son was transferred by the earpick.

Adolescent↗
PubMed1998

Benign form of congenital angulation of long bones associated with shortening of soft tissues.

We report a benign form of congenital angulation of long bones associated with shortening of soft tissues. The patients were three males and four females including two siblings. The average age at first examination was 6 months (range, 1-17 months) and that at the time of follow-up was 7 years (range, 13 months-11 years). The characteristics were short-limb type short stature, congenital multiple angulation deformities of the long bones of both upper and lower extremities, with almost the same angulation directions for all the patients and improvement of the deformities with age. There was also accelerated skeletal maturation, lack of epi-metaphyseal lesions, skin dimples, limitation of the ankle joint dorsiflexion, and inconspicuousness of skin creases on the flexor side of the elbow and knee. This phenotype is not consistent with any of the bent bone dysplasia group. Caffey's report [Caffey J (1947). Am J Dis Child 74:543-5621 included two different subtypes of bent bones, round bowing and sharp angulation, and the latter are similar to this report. However, Caffey's cases lack limitation of ankle dorsiflexion and reduced skin creases. An autosomal recessive mode of inheritance could be present in this subtype.

Bone and Bones↗
PubMed1998

Mechanisms of non-drowsiness after oral administration of TMK688, a novel antiallergic drug.

The mechanisms of non-drowsiness after oral administration of TMK688 (1- [[5'-(3"-methoxy-4"-ethoxycarbonyloxyphenyl)-2',4'-pentadienoyl ] aminoethyl]-4-diphenylmethoxypiperidine, CAS 110501-66-1) were investigated using mice. TMK688 inhibited the histamine-induced vascular permeability at oral doses of 3.2-10 mg/kg with an ID50 value of 5.4 mg/kg. More than 100 times higher doses were needed to prolong the hexobarbital-induced sleeping. Pyrilamine, a typical antihistamine agent, showed little difference among these doses and antiallergic drugs having antihistamine activity, i.e., terfenadine, azelastine and ketotifen, had effects between TMK688 and pyrilamine. The inhibitory activity of orally administered TMK688 against ex vivo [3H]-pyrilamine binding to mouse cerebral histamine receptors appeared at the same doses as its potentiating activity against hexobarbital-induced sleeping. When given orally, TMK688 was hydrolyzed to TMK777 (CAS 101619-11-8), then conjugated with glucuronic acid to TMK777-glucuronide. No TMK688 was detected in the blood. The main metabolite TMK777-glucuronide could hardly penetrate the blood-brain barrier because of its polarity. Although the plasma concentrations of TMK777 were far lower than those of TMK777-glucuronide, TMK777 was penetrable into the brain and the cerebral concentrations of TMK777 increased in parallel with the plasma concentrations of the drug. Since intracerebroventricularly-injected TMK777 prolonged the sleeping time, and since the threshold concentration of TMK777 in the cerebral cortex to potentiate the hexobarbital-induced sleeping was consistent despite different administration routes, the drowsiness elicited by markedly high doses of TMK688 is though to be caused by intracerebral TMK777. In other words, TMK688 does not seem to cause drowsiness at effective doses because of the poor prenetrability of its main metabolites into the brain.

Administration, Oral↗
PubMed1997

Comparison of ectopic osteoinduction in vivo by recombinant human BMP-2 and recombinant Xenopus BMP-4/7 heterodimer.

Two micrograms recombinant human bone morphogenetic protein-2 (rhBMP-2) and 2 microg recombinant Xenopus bone morphogenetic protein-4/7 heterodimer (rxBMP-4/7ht) were implanted into a calf muscle pouch in rats using atelopeptide type I collagen (CL) solution as the carrier. Three weeks later induced bone in the rhBMP-2 + CL group (group A; n=5) and the rxBMP-4/7ht + CL group (group B; n=5) was investigated radiologically and histologically. Bone trabeculum and marrow were induced in all cases of both groups. In group A the area of radioopaque oval shadows was 5.78 mm2, wider than 4.64 mm2 in group B. The radoopacity in group A was 74.6, higher than 57.6 in group B. Histometry of the microscopic views showed that the trabecular area was 0.92 mm2 in group A and 0.22 mm2 in group B, while the trabecular percentage occupied in the overall lump area was 18.07% in group A and 5.51% in group B. The trabecular form in group A was more massively coral than in group B. This study indicated that rhBMP-2 has a higher ectopic osteoinduction ability in vivo than rxBMP-4/7ht.

Animals↗
PubMed1997

Crystallization, preliminary diffraction and electron paramagnetic resonance studies of a single crystal of cytochrome P450nor.

Cytochrome P450nor (P450nor) is a heme-containing nitric oxide reductase from the denitrifying fungus, Fusarium oxysporum. This enzyme catalyzes the reduction of NO to N2O. In the present study, we report results from preliminary crystallographic and electron paramagnetic resonance (EPR) analysis of a single crystal of P450nor. The crystal was grown in 100 mM MES buffer at pH 5.6 using PEG 4000 as a precipitant. It belongs to the orthorhombic system with cell dimensions of a = 54.99 A, b = 82.66 A, c = 87.21 A, and the space group is P2(1)2(1)2(1). The crystal diffracts synchrotron radiation at higher than 2.0 A resolution, and therefore it is suitable for X-ray crystal structure analysis at atomic resolution. Bijvoet and dispersive anomalous difference Patterson maps show a clear peak corresponding to the heme iron. The structure solution is currently underway by means of MIR and MAD techniques. EPR analysis determined the orientation of the heme within the P450nor crystal.

Crystallography, X-Ray↗