Biomedical subjects
Publications and source records attributed to H Mizuta.
An extremely rare case of familial amyloidotic polyneuropathy (FAP) complicated by neuroarthropathy (Charcot joint) in the left knee joint and by intra-articular deposits of amyloid was observed. FAP-specific variant transthyretin (TTR) was found in the synovial fluid and amyloid deposits were confirmed in the synovium, cartilage and bone by Congo red staining and immuno-staining.
This paper compares two classifiers: Pseudo Bayesian and Neural Network for assisting in making diagnoses of psychiatric patients based on a simple yes/no questionnaire which is provided at the outpatient's first visit to the hospital. The classifiers categorize patients into three most commonly seen ICD classes, i.e. schizophrenic, emotional and neurotic disorders. One hundred completed questionnaires were utilized for constructing and evaluating the classifiers. Average correct decision rates were 73.3% for the Pseudo Bayesian Classifier and 77.3% for the Neural Network classifier. These rates were higher than the rate which an experienced psychiatrist achieved based on the same restricted data as the classifiers utilized. These classifiers may be effectively utilized for assisting psychiatrists in making their final diagnoses.
The expression of neurotrophin-3 (NT-3) in skeletal muscles was measured in rats with streptozotocin (STZ)-induced diabetes using Northern blot analysis. At 6 weeks after STZ induction of diabetes, the NT-3 mRNA level in the quadriceps and gastrocnemius muscles was decreased by 45 and 77%, respectively, compared with that in age-matched controls. Since NT-3 is considered to be essential for the maintenance of spinal proprioceptive afferent neurons, decreased NT-3 expression in target tissues would impair the integrity of afferent neurons and might be an earlier marker in the sensory neuronal damage observed in diabetes mellitus.
The localized form of tenosynovial giant-cell tumor is rarely located intraarticularly, especially in the large weight-bearing joints. We report the first case of localized, intraarticular tenosynovial giant-cell tumor arising from the anterior cruciate ligament of a knee in which locking and effusion had occurred. After arthroscopic removal of this tumor, the patient became asymptomatic.
OBJECTIVE: To examine the hypotheses that anterior cruciate ligament (ACL) reconstruction improves the proprioception of the knee beyond the level of ACL-deficient knees, and that proprioception of the knee correlates well with knee function after ACL reconstruction. PATIENTS: Fifty-three patients with ACL-reconstructed knees (22 men and 31 women), 30 physically active healthy volunteers with normal knees (15 men and 15 women), and 30 patients with chronic ACL-deficient knees (15 men and 15 women). MAIN OUTCOME MEASURES: A stabilometric assessment, which is considered to be a useful method for evaluating proprioception objectively, was used to compare the one-leg standing balance among three groups; and the relationship between subjective knee function, satisfaction, hop index, knee laxity, isokinetic thigh muscle strength, and one-leg standing balance in the ACL-reconstructed patients was also analyzed. RESULTS: The one-leg standing balance of the patients with ACL-reconstructed knees was still impaired compared with that of healthy volunteers (men, p < 0.05; women, p < 0.01), but significantly better than that of the patients with ACL-deficient knees (men, p < 0.001; women, p < 0.001). The one-leg standing balance of the patients with ACL-reconstructed knees correlated well with their functional outcomes such as subjective knee function (men, p < 0.001; women, p < 0.01), satisfaction (men, p < 0.01; women, p < 0.001), and hop index (men, p < 0.001; women, p < 0.001), whereas poor correlation was seen between functional outcomes and mechanical stability. CONCLUSIONS: The results suggest that knee function after ACL-reconstruction should be closely related with knee proprioception, and indicate that the usefulness of stabilometric assessment in the evaluation of the function of ACL-reconstructed knees.
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We compared the effect of various distraction frequencies on the gastrocnemius muscle by evaluating the histological findings, intramuscular enzyme contents, and DNA contents. In 15 rabbits, both tibiae were distracted 1 mm per day. The distraction frequency was 2 steps (0.5 mm/12 hour) by hand on the right side and 120 steps (0.0083 mm/12 minutes) by an auto-distractor on the left. The rabbits were divided into 3 subgroups based on length gain: 10%, 20%, and 30%. Histologically, there were no signs of fibrosis or edema and no differences in the number of necrotic cells, and intramuscular enzyme contents between the 2- and 120-step groups. The DNA content, however, was higher in the 120-step group at 30% lengthening in the middle of the muscle belly, and at 20% and 30% lengthening in the musculotendinous junction. Our findings suggest that an increase in the distraction frequency may promote DNA synthesis in the muscle, thus providing better muscle accommodation during bone lengthening.
The expression of somatostatin receptor (SSTR) subtypes and relative abundance of SSTR2 mRNA were examined in 18 pituitary adenomas using the reverse transcription-polymerase chain reaction (RT-PCR) method. SSTR1 and SSTR2 were expressed in all pituitary adenomas examined. Six of 9 somatotroph adenomas, 1 of 4 lactotroph adenomas and 1 of 2 thyrotroph adenomas also expressed SSTR5. SSTR3 and SSTR4 mRNAs were detected in 1 and 2 cases of somatotroph adenoma, respectively. SSTR2 mRNA expression was quantified by comparison with the PCR cycle-dependent amplification of beta-actin or cyclophilin. The relative abundance of SSTR2 mRNA varied greatly among adenomas with more than a 1000-fold difference. SSTR2 mRNAs in lactotroph adenomas were less abundant (P < 0.01) than those in somatotroph adenomas. No significant correlation was found between the relative abundance of SSTR2 mRNA levels and GH sensitivity to octreotide administration. However, one of the thyrotroph adenomas exhibited marked shrinkage in tumor size after octreotide therapy, in which SSTR2 mRNA was the most abundant among the adenomas examined. GH sensitivity to octreotide was not significantly different between SSTR5 mRNA positive and negative adenomas. In conclusion, SSTR2 mRNA levels varied greatly among pituitary adenomas but were not correlated with GH sensitivity to octreotide. Further investigations of functional SSTR subtype proteins and of postreceptor signal transductions are required to clarify the molecular mechanisms of octreotide action.
The relationships of the phasic period of interdigestive migrating contraction to gastrointestinal (GI) transit of drugs and their oral absorption were investigated in mongrel dogs by simultaneous oral dosing of acetaminophen (AAP) and salicylazosulfapyridine (SASP) at the starting points of the phase I and phase III periods of gastric contractions. Strain-gauge force transducers were surgically sutured onto the serosa of the GI tracts in the dogs to measure the interdigestive migrating contractions. The mean absorption time of AAP and the time for the first appearance of sulfapyridine (a bacterial metabolite of SASP in the colon) in plasma were used as the indices of gastric emptying time (GET) and small intestinal transit time (SITT), respectively. In individual dogs, the GET and the SITT at phase I showed a clear delay in comparison with those at phase III. For AAP used as a marker compound here, the systemic bioavailability after oral dosing to intact beagle dogs at doses of 3, 10, and 20 mg/kg was about 55, 63, and 79%, suggesting that AAP undergoes a non-linear hepatic clearance. At a dose of AAP 20 mg/kg, the systemic bioavailability of AAP was 100% in the case of dosing at phase III, but was reduced by half when dosing at phase I. These results indicate that, in oral dosing, the transit of drugs through the GI tract was clearly affected by the phases of gastric contractions.(ABSTRACT TRUNCATED AT 250 WORDS)
We investigated the effects of tibial lengthening by callotasis on glycosaminoglycan (GAG) metabolism of the knee articular cartilage in 30 rabbits. The distraction rate was 1 mm per day. On the right side, the daily distraction was in 2 steps, while on the left it was in 120 steps. The animals were divided into 3 subgroups based on length gain; 10, 20, and 30 percent, respectively. The knee joint fluid and medial tibial cartilage were examined by quantitative analysis of the GAG content and/or synthesis. The immunoreactivity for chondroitin sulfate in the cartilage was also examined by immunohistochemistry. For all length gains, the GAG concentration in the synovial fluid was higher on both sides than in controls, with no difference between sides. The GAG content and synthesis in the cartilage on the 2-step side decreased gradually with increasing length. On the 120-step side, the content did not differ from control values in any length gain, and the level of synthesis at 20 and 30 percent lengthening was higher than the control level. Our findings indicate that the alterations in GAG metabolism are attributable to increased mechanical stress on the articular cartilage, suggesting a moderate increase on the 120-step side compared to an excessive one on the 2-step side.
We evaluated in 20 Japanese white rabbits the effects of tibial lengthening on tibial nerve conduction and intraneural blood flow at the end of lengthening. Both tibiae were distracted 1 mm per day. The distraction frequency was in 2 steps (0.5 mm/12 h) on the right side and in 120 steps (0.0083 mm/12 min) on the left. The rabbits were separated into 4 subgroups based on the percentage of lengthening: 0 (control), 10, 20, and 30 percent. In the 2-step group, nerve conduction was delayed at 20 and 30 percent lengthening, compared to the control group, while in the 120-step group, it was delayed only at 30 percent lengthening. Intraneural blood flow in the 2-step group was decreased at 10, 20, and 30 percent lengthenings, while in the 120-step group it was reduced at 30 percent lengthening. Our findings indicate that an increase in the frequency of distraction reduces the impairment of nerve function during bone lengthening.
We investigated the effects of tibial lengthening by callotasis on the knee articular cartilage in 10 rabbits at 3 and 6 months after distraction. The distraction rate was 1 mm per day, until a 30 percent gain in length. On the right tibia, the daily distraction frequency was in 2 steps by hand, while on the left it was in 120 steps by an autodistractor. 5 animals were killed at 3 months and 5 at 6 months following distraction, and their knee joints were radiographically and histologically examined. On the 2-step side, arthrotic changes at 3 and 6 months after distraction were found in 3 of 5 and 4 of 5 knees, respectively. The severity of change increased with time. On the 120-step side, however, no arthrotic changes were found, except in one knee at 6 months. Our findings suggest that by increasing the frequency of distraction for limb lengthening one can prevent the onset of arthrosis in adjacent joints.
We describe the results of conservative treatment for complete midsubstance tears of the anterior cruciate ligament (ACL) in 18 skeletally immature patients, followed for a minimum of 36 months. Six patients had an ACL reconstruction during the follow-up period and were assessed immediately before their operation. The average time from initial injury to evaluation was 51 months. All patients had symptoms when reviewed. The modified Lysholm knee score showed one excellent result, one good, eight fair, and eight poor with a mean score of 64.3. Only one patient had returned to her preinjury level of athletics. Secondary meniscal tears were confirmed in six patients, and three more had the clinical signs of a tear at follow-up. Radiological evidence of degenerative changes was found in 11 of the 18 patients. We conclude that the results of non-operative treatment for ACL injuries in this age group are poor and not acceptable.
The gastrointestinal (GI) physiology of beagle dogs was effectively regulated with a combined treatment using intramuscular pentagastrin (10 micrograms/kg x 2) and intravenous atropine sulfate (0.02 mg/kg x 1). The superiority of the GI physiology regulated-dogs over the intact dogs was confirmed by comparative bioavailability studies using two classes of preparations of poorly water-soluble 4-(2-chlorophenyl)-2-[2-(4-isobutylphenyl)ethyl]-6,9-dimethyl-6H- thieno[3,2-f][1,2,4]triazolo[4,3-a][1,4]diazepine (Y-24180). Both the fine granules and the tablets of Y-24180 exhibited similar absorption profiles in the intact dogs, whereas the latter preparations revealed a delayed plasma curve of the drug in the regulated-dogs. The absorption profiles of the two classes of Y-24180 preparations in the regulated-dogs simulated those in healthy volunteers. The combined-treatment of beagle dogs with pentagastrin and atropine sulfate was suggested to supply a useful animal model for predicting the absorption characteristics of poorly water-soluble drugs and their preparations in humans.
The utility of gastrointestinal physiology regulated-dogs (regulated-dogs) was evaluated in a bioavailability study. The gastrointestinal physiology of beagle dogs was regulated with a combined-treatment of intramuscular pentagastrin and intravenous atropine sulfate. Theophylline has been regarded as a drug that is absorbed completely in the entire gastrointestinal tract but slowly in the colon for humans. A commercial sustained-release tablet (SR tablet) of theophylline and a commercial conventional tablet of aminophylline (theophylline hemiethilenediamine salt) were chosen as model preparations in this study. In the regulated-dogs, the drug absorption was almost complete for the conventional tablet. The bioavailability of the SR tablet accounted for 76% in the regulated-dogs and 71% in intact dogs relative to that of the conventional tablet in the regulated-dogs, respectively, but no significant difference was detectable between these values. An advantage of the regulated-dogs over the intact dogs was, however, revealed in the time-profiles of the cumulative percentage of theophylline absorbed from the SR tablet, suggesting a modification of drug absorption by the prolonged arrival of the tablet to the colon.
A method is presented that relates the heart rate variability (HRV) to the change in instantaneous lung volume (ILV) under non-stationary conditions. Methods utilizing a recursive least squares (RLS) algorithm and a modified Widrow LMS algorithm are proposed to keep track of changes in impulse response of HRV to ILV. Results are presented of real data analysis and a dedicated system is proposed utilizing DSP chips for the real time data processing.
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