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Biomedical subjects

M Aoki

Publications and source records attributed to M Aoki.

At least 955 records · Page 53Linked to original sources

Early active motion and weightbearing after cross-stitch achilles tendon repair.

Twenty-two closed Achilles tendon ruptures caused by sports injuries in 22 patients (average age, 37.6 years) were repaired with Kirschmayer core suture and cross-stitch epitenon suture, and early active ankle motion with weightbearing was implemented after surgery. This study was undertaken to evaluate the effectiveness of the repair technique and rehabilitation protocol by assessing clinical results and magnetic resonance imaging findings. The follow-up period averaged 24.6 months. Twenty of the tendons (91%) healed without rerupture, and two tendons (9%) suffered a partial rerupture at 23 and 56 days, respectively. Active ankle extension reached from the minus range to 0 degree in an average of 9.7 days, and ankle motion recovered to normal in an average of 6.0 weeks. Full weightbearing without heel raising became possible in an average of 16.4 days, and heel raising with both legs became possible in an average of 7.3 weeks. The patients returned to full sports activity in 13.1 weeks. The interval until the area of high-intensity signal at the tendon repair site on T2-weighted magnetic resonance imaging scans became intermediate-intensity signal averaged 6.9 weeks, and the tendon repair site became low-intensity signal in an average of 12.6 weeks, demonstrating excellent tendon healing. Treatment employing Kirschmayer core suture and cross-stitch epitenon suture may help athletes return to sports activity in a shorter period than that allowed by previous methods of repair for Achilles tendon ruptures.

Achilles Tendon↗

Control of the nasal mucosa by the tonic activities of the autonomic nervous system in dogs.

We studied the effects of stimulation and acute denervation of the cervical sympathetic nerve and the vidian nerve on the nasal vascular tone, as measured by intranasal balloon pressure. Significant vasoconstriction was found during electrical stimulation of the cervical sympathetic nerve. When the cervical sympathetic nerve was sectioned, causing a transient vasoconstriction due to the stimulatory effect of the nerve injury, then significant vasodilation was found in 23 out of 30 experiments. Significant vasodilation during electrical stimulation of the vidian nerve and slight but significant vasoconstriction after sectioning of the vidian nerve were also found. In addition, we found spontaneous nerve discharges in the cervical sympathetic nerve trunks. These nerve discharges increased after stopping the respiratory pump. Differences in these sympathetic nerve discharges between the sides of the body were also recognized.

Animals↗

Respiration-related movements of the nose in dogs.

We studied the respiration-related movements of the canine nose by examining the respiratory oscillations of intranasal balloon pressure and EMG activities of the dilator nares in dogs. Under spontaneous respiration, balloon pressure decreased and EMG activities increased during the early inspiratory phase. These respiratory movements of the nose differed and changed reciprocally in strength between the two sides of the body spontaneously, after painful stimulation or intranasal histamine administration. When the muscle relaxant was administered and the respiration was controlled by the ventilation pump, the intranasal balloon pressure increased during the inspiratory phase. This phenomenon had a completely inverted pattern compared with that during spontaneous respiration. Furthermore, even when the ventilation pump was stopped, respiration-like spontaneous oscillations of the intranasal balloon pressure were recognized. These were abolished by sectioning of the ipsilateral cervical sympathetic nerve trunk. From these findings, the respiration-related movements of the nose were thought to be controlled not only by the cardiac output and the vagal nerve reflexes but also by respiratory activities in the nervous systems controlling the nose, which might be originated from the medullary respiratory centres.

Animals↗

Spontaneous nasal oscillations in dog. A mucosal expression of the respiration-related activities of cervical sympathetic nerve.

We studied the respiratory oscillations of the nasal mucosa in dogs. Even after temporarily stopping the respirator, intranasal balloon pressure showed respiration-related oscillations (spontaneous nasal oscillations). These spontaneous oscillations were recorded in all 21 dogs. Spontaneous nasal oscillations were not abolished even after thoracotomy, vagotomy and vidian neurectomy. Only cervical sympathectomy could to a large extent abolish the spontaneous nasal oscillations. Furthermore, the spontaneous nasal oscillations were found to be synchronized with the respiration-related fluctuations of cervical sympathetic nerve activities. Rhythms of the spontaneous nasal oscillations were not dependent on the rates of artificial ventilation, but were closely related to the rates of spontaneous respiration before administering the muscle relaxant. On some occasions, we recognized remarkable differences in the height of waves of the spontaneous nasal oscillations between the sides of the body. On eight occasions in 5 dogs, reciprocal changes of the dominant side of bilateral spontaneous nasal oscillations were noted which might be an expression of the nasal cycle.

Animals↗

Osteoclast origin of giant cells in giant cell tumors of bone: ultrastructural and cytochemical study of six cases.

To clarify the histogenesis of giant cells appearing in giant cell tumors of bone (GCTB), an ultrastructural and cytochemical study of six cases was performed with both acid phosphatase (ACPase) and tartrate-resistant acid phosphatase (TRACPase) as marker enzymes. TRACPase is considered a specific marker for osteoclasts. ACPase was demonstrated in the macrophagelike stromal cells, the multinucleated giant cells, and the infiltrating macrophages. The enzyme reaction was localized in lysosomal dense bodies and Golgi areas. Intense TRACPase activity was demonstrated in the multinucleated giant cells, whereas a weak reaction was found in the macrophagelike stromal cells. The multinucleated giant cells and macrophagelike stromal cells resembled osteoclasts with regard to the subcellular localization of TRACPase. The present results suggest that the giant cells in GCTB are indeed derived from osteoclasts.

Acid Phosphatase↗

Successful emergency treatment with a transjugular intrahepatic portosystemic shunt for life-threatening Budd-Chiari syndrome with portal thrombotic obstruction.

We report successful treatment of acute severe Budd-Chiari syndrome with portal venous thrombosis. The prognosis of patients with this condition is poor, because the therapeutic options are limited. A 38-year-old woman with polycythemia vera was admitted in a critical condition, and Budd-Chiari syndrome complicated by portal venous thrombosis was diagnosed. Tissue plasminogen activator and urokinase were infused systemically and were partially effective. Transjugular intrahepatic portosystemic shunting to reduce the high portal venous pressure was performed successfully and, eventually, her general condition improved. Our experience indicates that emergency transjugular intrahepatic portosystemic shunting is an effective therapeutic modality for controlling portal hypertension in patients with severe Budd-Chiari syndrome with portal venous thrombosis.

Adult↗

Familial amyotrophic lateral sclerosis with posterior column degeneration and basophilic inclusion bodies: a clinical, genetic and pathological study.

We report an autopsy case of familial amyotrophic lateral sclerosis (FALS). The patient was a Japanese woman with hereditary burden. Family history revealed 12 patients with FALS over four generations. She developed muscle weakness of the proximal part of the upper extremities at age 42, followed by dysarthria, dysphagia, muscle weakness and atrophy in the lower extremities, spasticity, hyperreflexia and Babinski's sign. At age 44, she needed ventilatory support. At age 45, she died of bronchopneumonia. The total duration of the disease was three years and one month. Genetic study showed the absence of a mutation in the Cu/Zn superoxide dismutase-1 gene. Neuropathological examination revealed not only neuronal loss in the upper and lower motor neuron and Clarke's column, but also degeneration of the pyramidal tracts, middle root zone of the posterior column and posterior spinocerebellar tract. Bunina bodies and Lewy body-like inclusion bodies were absent. A few basophilic inclusion bodies were present in the neurons of the brain stem and anterior horn of the lumbar cord. Based on these clinical, genetic and pathological findings with a review of the literature, we concluded that our case was the first reported case of FALS with posterior column involvement and basophilic inclusion bodies.

Adult↗

Effect of bovine lactoferrin on the immune responses of captive bottlenosed dolphins (Tursiops truncatus) being transported over long distances.

Bovine lactoferrin was administered orally, in feed, to six bottlenosed dolphins (Tursiops truncatus) before they were transported for approximately six hours; their stress responses were compared with those of five untreated dolphins. During the journey the dolphins had an increased plasma concentration of cortisol, and lymphopenia, eosinopenia and mild neutrophilia, indicating a stress response. The administration of lactoferrin did not affect the function of the dolphins' polymorphonuclear leucocytes, but affected their leucogram by maintaining the number of circulating eosinophils.

Administration, Oral↗

Antinociceptive activity of intracisternally and intrathecally administered eptazocine, a novel analgesic, in mice.

Antinociceptive potency of eptazocine (1-1,4-dimethyl-10-hydroxy-2,3,4,5,6,7-hexahydro-1,6-methano-1H-4-ben zazonine), a novel analgesic derived from homobenzomorphan, was compared with that of morphine and pentazocine after intracisternal and intrathecal administration into conscious mice using acetic acid-induced writhing, tail pressure and hot plate tests. The rank order of potency for inhibition of writhing after intracisternal administration was morphine greater than eptazocine greater than pentazocine. In contrast, the intrathecal compounds inhibited writhing with a rank order of potency of eptazocine greater than or equal to morphine greater than pentazocine. On the tail pressure and hot plate tests after intrathecal administration, ED50 ratios of eptazocine to morphine were much smaller than that on the writhing test. Systemic naloxone did not antagonize the antinociceptive effect of intrathecal eptazocine on the writhing test. These results suggest that the antinociceptive action of eptazocine is rather specific to chemical nociceptive stimuli and may be mediated via spinal non mu-opioid receptors in the mouse.

Analgesics↗

Stimulation of mammary tumourigenesis and inhibition of uterine adenomyosis by suppressed progesterone effects in SHN mice.

It has been shown in mice that progesterone stimulates both mammary tumourigenesis and uterine adenomyosis in intact animals in the presence of normal levels of prolactin and oestrogen. From the view-point of the high dependence of progesterone upon other hormones, the effects of suppressed progesterone action on mammary and uterine lesions were studied in this paper. Subcutaneous implantation of RU 486, an antiprogesterone, enhanced preneoplastic and neoplastic mammary gland growth in SHN virgin mice associated with elevated plasma prolactin levels and continued vaginal oestrous stage. This mammary gland growth stimulated by RU 486 was arrested by additional treatment with progesterone. On the contrary, RU 486 treatment markedly suppressed the development of uterine adenomyosis, which was counteracted only by progesterone supplement for a long period in old mice. The previous and the present findings conclude that progesterone stimulates mammary tumourigenesis by acting synergistically with prolactin and oestrogen when the latter hormones are at normal levels, but it prevents tumourigenesis by acting antagonistically with high levels of prolactin and oestrogen. They further confirmed the importance of progesterone in the development of adenomyosis, while its relationship with prolactin and oestrogen is not understood so well as it is in mammary tumourigenesis.

Adenoma↗

A non-alcoholic Japanese patient with Wernicke's encephalopathy and Marchiafava-Bignami disease.

In Japan Wernicke's encephalopathy is not rare, but only one case of Marchiafava-Bignami disease has been reported. In our case, Wernicke lesions were found in the mamillary bodies, septal nuclei, and periventricular regions. Involvement of the septal nuclei is rare in this encephalopathy. A characteristic Marchiafava-Bignami lesion was observed only in the anterior part of the corpus callosum. From the clinicopathologic viewpoint, Wernicke's encephalopathy might have preceded Marchiafava-Bignami disease in our case. To our knowledge, only two cases without a history of alcoholism and both suffering from Wernicke's encephalopathy and Marchiafava-Bignami disease have been documented. However, in both cases Wernicke lesions were atypical, since characteristic lesions were absent in the mamillary bodies and in the regions surrounding the third ventricle and the aqueduct. Ours appears to be the first report on a non-alcoholic patient with typical lesions of both diseases.

Alcohol Drinking↗

Mitochondrial DNA analysis of Sporothrix schenckii in Costa Rica.

Mitochondrial DNA (mtDNA) types using restriction patterns with HaeIII were investigated in 21 clinical isolates of Sporothrix schenckii in Costa Rica. Nineteen isolates were found to be a new mtDNA type (Type 14), while the remaining two were Type 3 and Type 6. Based on the phylogeny of 14 mtDNA types constructed by estimating sequence divergences of mtDNA, S. schenckii were clustered into two main groups: Group A and Group B, with Type 14 and Type 3 included in Group A, and Type 6 in Group B. The results suggest that isolates of Group A may exist mainly in Central America including Costa Rica.

Costa Rica↗

Evidence for the involvement of NMDA receptors in vestibular compensation.

The involvement of NMDA (N-methyl-D-aspartic acid) receptors in the initial stage of the vestibular compensation was evaluated by examining the effect of MK-801 on this compensation in guinea pigs. MK-801, injected 30 min before induction of unilateral labyrinthectomy by an arsanilate, significantly (P < 0.05) reduced the maximum frequency of the spontaneous nystagmus (SN) towards both the arsanilate-applied and the intact sides. In addition, injection of arsanilate into the opposite middle ear, 60 days subsequent to induction of the unilateral labyrinthectomy, suppressed the SN towards the second injected side, but had no effect on the SN towards the first injected side. These results suggest that NMDA receptors may be linked to the initiation of the vestibular compensation.

Animals↗

MRI finding of chronic hemorrhagic empyema: a case report.

We report a case of 64-year-old man with chronic hemorrhagic empyema. T1- and T2-weighted MR images showed variably hyperintense areas in the tumor that reflected the presence of fresh and old hematoma. Gd-DTPA-enhanced MRI revealed capillary bleeding in the periphery of the mass.

Chronic Disease↗