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T Wakao

Publications and source records attributed to T Wakao.

At least 19 recordsLinked to original sources
PubMed1997

Diabetic neuropathy in sucrose-fed Otsuka Long-Evans Tokushima fatty rats: effect of an aldose reductase inhibitor, TAT.

In an animal model of human non-insulin dependent diabetes mellitus (NIDDM), Otsuka Long-Evans Tokushima Fatty (OLETF) rats were fed with sucrose for 8 weeks to obtain severe hyperglycemia. The effects of sucrose administration on peripheral nerve functions, motor nerve conduction velocity (MNCV) and coefficient of variance of R-R interval (CVR-R), were investigated with concomitant measuring of sciatic nerve blood flow (SNBF), ADP-induced platelet aggregation and polyol content in the sciatic nerves. The effects of an aldose reductase inhibitor, TAT, on these parameters were also studied. Administration of sucrose to OLETF rats caused significant body weight reduction and remarkable hyperglycemia. Sucrose-fed OLETF rats demonstrated significantly delayed MNCV, decreased CVR-R, reduced SNBF and increased platelet aggregation activity to ADP. Sorbitol and fructose accumulation, and myo-inositol depletion in sciatic nerves were observed only in sucrose-fed OLETF rats. These abnormalities were all ameliorated by the treatment with TAT. These observations suggest that the sucrose-fed OLETF rat is a useful animal model for studying the pathogenesis of diabetic neuropathy in human NIDDM, and that an aldose reductase inhibitor is a useful therapeutic agent for the treatment of diabetic neuropathy.

Aldehyde Reductase↗
PubMed1996

Effect of propionyl-L-carnitine on motor nerve conduction, autonomic cardiac function, and nerve blood flow in rats with streptozotocin-induced diabetes: comparison with an aldose reductase inhibitor.

The effects of propionyl-L-carnitine (PCAL) on caudal motor nerve conduction velocity, the coefficient of variation of the R-R interval on the electrocardiogram, and sciatic nerve blood flow were compared with those of [5-(3-thienyl)tetrazol-1-yl] acetic acid monohydrate, an aldose reductase inhibitor, in rats with streptozotocin-induced diabetes. Diabetic control rats showed significantly delayed nerve conduction (P < .05), decreased R-R variability (P < .05) and reduced sciatic nerve blood flow (P < .05). Oral administration of PCAL (0.5 g/kg/day) and [5-(3-thienyl)tetrazol-1-yl] acetic acid monohydrate (0.05% in the diet: 60 mg/kg/day) for 8 weeks significantly improved both nerve conduction (P < .05) and R-R variability (P < .05) in diabetic rats, along with the normalization of sciatic nerve blood flow. PCAL treatment increased the nerve tissue levels of carnitine and myo-inositol and reduced the serum triglyceride level in diabetic rats. Our results suggests that PCAL could have therapeutic potential for the treatment of diabetic neuropathy.

Aldehyde Reductase↗
PubMed1995

Polyol pathway, 2,3-diphosphoglycerate in erythrocytes and diabetic neuropathy in rats.

The relationship between the 2,3-diphosphoglycerate concentration in red blood cells as a biological indicator of tissue hypoxia and diabetic neuropathy, and the effect of a potent aldose reductase inhibitor, (2S,4S)-6-fluoro-2'5'-dioxospiro [chroman-4,4'-imidazolidine]-2-carboxamide (SNK-860), on both were investigated in streptozotocin-induced diabetic rats. Diabetic rats demonstrated significantly delayed motor nerve conduction velocity and reduced sciatic nerve blood flow. Altered biochemical features in the sciatic nerves, including a marked accumulation of sorbitol and fructose, myo-inositol depletion and decreased Na+/K(+)-ATPase activity were also detected in diabetic rats. These defects were accompanied by a decrease in the red blood cell 2,3-diphosphoglycerate concentration. Treatment with SNK-860 partially or completely ameliorated these abnormalities. These observations suggest that a decrease in the red blood cell 2,3-diphosphoglycerate concentration is one of the factors contributing to tissue hypoxia, which results in diabetic neuropathy, and that this decrease is mediated through an aldose reductase inhibitor-sensitive pathway.

2,3-Diphosphoglycerate↗
PubMed1995

Prevention of abnormalities in motor nerve conduction and nerve blood-flow by a prostacyclin analog, beraprost sodium, in streptozotocin-induced diabetic rats.

The effects of the prostacyclin analog beraprost sodium on motor nerve function and nerve blood-flow were examined in streptozotocin-induced diabetic rats. Oral administration of beraprost sodium 0.1 mg/kg/day for 8 wks significantly (P < 0.001) improved caudal motor nerve conduction velocity and sciatic nerve blood-flow, both of which are impaired in diabetic rats. Beraprost sodium did not affect glucose, sorbitol, or fructose levels in the sciatic nerve. However, a decreased content of cyclic AMP in the sciatic nerve and higher level of thromboxane B2 in the thoracic aorta of diabetic rats, as compared with those in normal rats, were reversed by the treatment with beraprost sodium (P < 0.01). Results suggest that beraprost sodium may have value in treating diabetic neuropathy, mainly by improving endoneurial blood-flow.

Animals↗
PubMed1995

Effect of a potent new aldose reductase inhibitor, (5-(3-thienyltetrazol-1-yl)acetic acid (TAT), on diabetic neuropathy in rats.

(5-(3-Thienyl)tetrazol-1-yl)acetic acid (TAT), a novel potent aldose reductase inhibitor, was administered for 4 weeks to rats with streptozotocin-induced diabetes. Physiological and biochemical studies were subsequently conducted on rat nerve tissue and erythrocyte sorbitol content was estimated. Sciatic nerve blood flow (SNBF) was markedly lower (about 43.4%) in untreated diabetic (DC) rats than in non-diabetic controls (NC). A significant delay in caudal motor nerve conduction velocity (MNCV) and significantly higher glucose, sorbitol and fructose values were observed in the sciatic nerve, accompanied by a markedly higher sorbitol concentration in erythrocytes. In contrast, TAT-treated diabetic groups (DT-10, DT-40 and DT-200) had significantly higher SNBF, MNCV and sciatic nerve myo-inositol values and lower sciatic nerve sorbitol and fructose levels and erythrocyte sorbitol concentration than the DC group. There were good correlations between SNBF and MNCV (r = 0.672, P < 0.001) and between SNBF and erythrocyte sorbitol (r = 0.455, P < 0.003). These findings suggest that both vascular and metabolic factors play an important role in diabetic neuropathy and the effect of aldose reductase inhibitors on diabetic neuropathy may be mediated by at least these two factors.

Aldehyde Reductase↗
PubMed1994

Factors affecting functional prognosis in survivors of primary central nervous system germinal tumors.

We evaluated 79 patients of whom 62 survived treatment for intracranial germinal tumors between 1964 and 1992. The survivors were assessed for their Karnofsky scores and intellectual and reproductive functions to verify factors associated with better prognosis. Thirty-one tumors were pineal, 17 were suprasellar, and ten were in the basal ganglia. These included 50 germinomas, five teratomas, and seven tumors of extra-embryonic origin producing alpha-fetoprotein or human chorionic gonadotropin. Although patients with germinoma or benign teratoma had better Kaplan-Meier survival rates than those with extra-embryonic origin tumors, the mean Karnofsky scores of the survivors did not differ significantly among the three histologic groups. On the other hand, although survival rates did not differ significantly among different tumor site groups, the mean Karnofsky score of the pineal group was higher than that of the suprasellar or basal ganglia group. Intellectual and reproductive functions were severely affected in the basal ganglia and suprasellar tumor groups, respectively. The Karnofsky score of survivors treated after 1977 was higher than for those treated before 1977. The score of patients who received less than 55 Gy irradiation was better than those who received more than 55 Gy. No patient who received less than 45 Gy developed a recurrence, suggesting that a lower dose may suffice for pure germinomas. Tumors of extra-embryonic origin, however, should be treated with combined chemotherapy to minimize subsequent irradiation. Factors affecting survivors' capabilities are discussed.

Adolescent↗
PubMed1993

Granulomatous angiitis of the central nervous system--case report.

A 22-year-old male presented with granulomatous angiitis manifesting as headache. Computed tomography (CT) demonstrated a low-density area and ring-like enhancement in the right frontoparietal region. Steroid therapy caused rapid improvement in the signs and symptoms. Withdrawal of steroid was followed by recurrence of the headache and low-density area. The steroid treatment was resumed until he became asymptomatic 3 months after admission. He was followed up as an outpatient once every 2 weeks. One month after discharge, he complained of mild headache, and CT again demonstrated a mild increase in the low-density area. He was followed up continuously without steroid treatment. Two months after discharge, he suddenly lost consciousness, and CT demonstrated multiple intracerebral hematomas in the bilateral parietal regions. Removal of an intracerebral hematoma in the right parietal region and external decompression were carried out, but he died 3 days later. Histological examination of tissues from the right parietal cortex and leptomeninges demonstrated granulomatous inflammation with several giant cells in the vessels of the cerebral cortex and leptomeninges.

Adult↗
PubMed1990

Tuberculous brain infection located in an old cerebral infarct: CT changes with successful conservative therapy.

A case of tuberculous brain infection following tuberculous meningitis in a 67-year-old man is presented. It was located in an old cerebral infarct associated with left internal carotid artery occlusion. CT demonstrated capsule enhancement in the left temporal area after iodinated contrast medium. Chemotherapy with INH, RFP and SM diminished the lesion and the capsule disappeared thirteen months later. It is suggested that a relatively long clinical history together with the appearance of a thick-walled abscess-like lesion on the CT scan is consistent with the diagnosis of tuberculous brain infection, perhaps an abscess.

Aged↗
PubMed1989

[Multiple myeloma manifesting as a solitary cranial tumor. Case report].

A 76-year-old female struck her head in the parietal region and noticed a soft scalp mass. Approximately 3 months later, the mass was enlarged and she was evaluated at a local hospital. Although the tentative diagnosis was old subcutaneous hematoma, incision of the scalp revealed not hematoma but rather a tissue and bony defect. On admission to the authors' institution, she was found to have a round, smooth, subcutaneous mass in the upper left parietal region. The tumor was about 5 cm in diameter and 4 cm in height, and was soft, nonpainful, and pulsatile. Plain X-rays revealed an osteolytic lesion in the left parietal bone. Computed tomography demonstrated a high-density lesion corresponding to the bony defect, which was homogeneously enhanced by contrast material. Left external carotid angiography showed the mass to be vascular, its main feeder being the middle meningeal artery. It was concluded that the tumor originated from the diploë. The tumor was subtotally removed, and histopathological examination showed it to be a plasmacytoma. Laboratory tests, including protein electrophoresis, disclosed hypergammaglobulinemia with M-spikes. Immunoelectrophoresis demonstrated a serum paraprotein of immunoglobulin G kappa specificity. Multiple myeloma diffusely involving bone is well known, but a soft mass alone with a bony defect in the cranial vault is very rare. The clinical features and treatment of silent, solitary masses associated with multiple myeloma are discussed.

Aged↗
PubMed1989

[Examination of periodontal disease with gingival crevicular fluid. Correlation between capacitance and clinical findings].

An intimate relationship between the inflammatory state of the gingiva and the amount of gingival crevicular fluid (GCF) is well known. For the measurement of the volume of GCF, filter paper has been used in the past. In the present study, an electrostatic capacity measuring apparatus with sensor that is insertable into gingival sulcus was fabricated. Capacitance of GCF was measured in patients with periodontitis and the following results were obtained. 1. The measuring apparatus was controlled by a personal computer to obtain the data every 0.1 second. As the GI increased at the site of measurement, higher values were obtained, with longer persistence of the trend of increase in the measured value. 2. In view of the stability of the measured values, the amount of GCF appeared to be best expressed as the value obtained after 10 seconds. 3. The correlation between the capacitance and the clinical findings was evaluated at 500 sites. The correlation was the highest in GI followed by P1I, GBI and PD, suggesting the utility of this method in the detection of initial gingival inflammation.

Electrolytes↗
PubMed1989

Epidermoid tumors of Meckel's cave: case report and review of the literature.

Lesions of Meckel's cave are extremely uncommon and difficult to diagnose. The symptoms and signs are variable, and the lesions may not appear on routine roentgenographic or computed tomographic examination. A patient with a small epidermoid tumor of Meckel's cave that was diagnosed by magnetic resonance imaging is herein reported. The epidermoid appeared as a low-intensity mass on the T1-weighted image and as a high-intensity mass on the T2-weighted image. Coronal sections defined the anatomic relationship to the trigeminal nerve. Preoperative recordings of the trigeminal sensory evoked response may be predictive of postoperative recovery of neurological deficits. Furthermore, intraoperative recording was extremely useful in avoiding inadvertent neurological injury. Review of the literature confirms the rarity of this lesion and the usefulness of magnetic resonance imaging in diagnosing it, although based on a limited number of cases.

Adult↗
PubMed1986

Spontaneous resolution of chronic subdural hematomas.

Four patients with chronic subdural hematomas, all of which resolved spontaneously, were followed from the time of injury to resolution of the chronic subdural hematoma. Periodic computed tomographic (CT) scans showed spontaneous resolution 78, 174, 231, and 326 days after the development of the chronic subdural hematoma, respectively. Features of the CT scans and a possible mechanism of spontaneous resolution are discussed.

Adult↗
PubMed1985

The incidence and developmental process of delayed traumatic intracerebral haematomas.

Although delayed traumatic intracerebral haematomas (DTICH) have been frequently reported especially after the advent of computerized tomography (CT), the developmental processes of traumatic intracerebral haematomas and the incidence of DTICH have not been described precisely. Based on early sequential CT examinations of 84 intracerebral haematomas for which initial CT scans were performed as early as within 6 hours of injury, we could ascertain four types of the developmental processes: Type I (39%) included the haematomas which were already evident in the initial CT scans, Type II (11%) the haematomas which were small or medium initially and increased their sizes afterwards, Type III (24%) the haematomas of which admission CT scans could not demonstrate any changes at the sites of development of the haematomas, and Type IV (26%) the haematomas of which initial CT scans showed a salt and pepper or flecked high-density appearance. Types III and IV denoted the DTICH and accounted for 50% of all the haematomas. Therefore, DTICH are thought to be not as uncommon as previously reported. Aetiologies and changes in the concepts of the DTICH are discussed, and it is stressed that, in the cases with eventual extra- and intra-cerebral combined haematomas, any surgical treatment of an extracerebral haematoma plays an important role in the development of DTICH.

Adolescent↗
PubMed1985

Intracranial granuloma caused by Aspergillus fumigatus.

A case is reported of intracranial granuloma caused by Aspergillus fumigatus involving the anterior cranial fossa and the frontal lobe. In this case, clinical symptoms developed about 5 years before the diagnosis was made. The final diagnosis was made by a craniotomy. The patient was treated with an extensive excision and chemotherapy, but finally he failed to respond to these treatments. We compile a summary of reported cases with a tabulation of pertinent information and discuss the pathogenesis, prognosis, and difficulty in treating this infection.

Aspergillosis↗
PubMed1985

The incidence of delayed traumatic intracerebral hematoma with extradural hemorrhages.

After introduction of computerized tomography (CT), we experienced 22 patients with traumatic extradural and intracerebral combined hematomas, of whom 15 underwent sequential CT scans. In 14 of the 22 patients or 13 of the 15 patients whose initial CT scans were performed early, within 6 hours after injury, intracerebral hematomas developed more slowly than extradural hematomas. In ten of the 13 patients, development of intracerebral hematomas was demonstrated only after removal of extradural hematomas, and in four patients acute brain swelling was observed during surgery. Therefore it is emphasized that the incidence of post-surgical intracerebral hematoma with extradural hemorrhages is high and that acute brain swelling during surgery for extradural hematomas is largely caused by the delayed intracerebral hematomas.

Adult↗