Effects of isatin, an endogenous MAO inhibitor, on dopamine (DA) and acetylcholine (ACh) concentrations in rats

Isatin (indole-2,3-dione), an endogenous inhibitor of monoamine oxidase (MAO), has several physiological properties for stress and anxiety. We previously identified isatin in the brain of stroke-prone spontaneously hypertensive rats (SHRSP) using gas-chromatography mass spectrometry. This study elucidated the effects of isatin on the ACh and DA levels of brain tissues in rats. Furthermore, we evaluated the effect of isatin on DA levels in a rat model of Parkinson's disease induced by Japanese encephalitis virus. Striatal ACh and DA levels significantly increased at 2 hours after isatin (50-200 mg/kg, i.p.) administration. Perfused through a microdialysis probe, isatin (10(-6)-10(-4) M) also produced a significant and concentration-dependent increase in the ACh and DA concentrations in the perfusate from the rat striatum. Furthermore, urinary isatin concentrations in patients with Parkinson's disease tend to increase according to the severity of disease. Isatin (100 mg/kg, i.p.) significantly increased striatal DA levels in a rat model of Parkinson's disease. These results suggest that urinary isatin may become a diagnostic marker for the clinical severity of Parkinson's disease and that endogenous isatin, a new biological modulator, may play a role in the regulation of the brain levels of ACh by increasing the level of DA under stress.     

Effect of ticlopidine on exercise-induced platelet aggregation and exercise tolerance time in patients with ischemic heart disease

Platelet aggregation is one of the most important mechanisms for acute myocardial infarction during exercise. We sought to evaluate the effect of ticlopidine (TP) on platelet aggregation (PA) during exercise in patients with ischemic heart disease (IHD). We studied 38 patients with IHD, 26 patients with effort angina pectoris, and 12 patients with a previous myocardial infarction. In protocol I, subjects were divided into two groups. Drugs altering platelet aggregation were withheld 2-4 weeks before the study in 25 patients (control group). TP (200 mg/day) was administered for 7 days in 13 patients (ticlopidine group). A symptom-limited modified Bruce protocol treadmill exercise test was performed. PA was measured at rest and after exercise by using optical densitometry induced by adenosine diphosphate (ADP). PA ratio (percentage of maximum) was compared. In protocol II, in 12 patients, treadmill exercise test and PA measurement were performed with and without TP. PA significantly increased after exercise in control (from 51.7+/-23.3% to 64.4+/-27.7%, p < 0.01) and ticlopidine (from 31.9+/-10.5% to 42.0+/-20.4%, p < .01) groups; however, its grade was lower in the ticlopidine group than in the control group. After exercise, PA was lower in the ticlopidine group than in control group (42.0+/-20.4% vs. 64.4+/-27.7%; p < 0.01). In the same patients, PA was lower with TP than without TP after exercise. Treadmill exercise-tolerance time was greater in the ticlopidine group than in the control group, but not statistically significant (762.3+/-139.2 vs. 711.6+/-169.6 s; NS). Exercise-tolerance time was significantly greater with TP than without TP in same patient (791.7+/-98.9 vs. 733.3+/-152.8 s; p < .05). TP suppressed the increase of PA during exercise and increased the exercise-tolerance time in patients with IHD.     

Immunocytochemical localization of aromaticl-amino acid decarboxylase and catechol-O-methyltransferase in blood vessel wall of the human dental pulp

Relatively large amounts of DOPA as compared with the concentration of norepinephrine are found in human dental pulp. AADC and COMT are localized in blood vessel walls of human dental pulp. This localization suggests a functional relationship between COMT and AADC with regard to the metabolism of DOPA.     

Immunolocalization of basic fibroblast growth factor during wound repair in rat retina after laser photocoagulation

Background: Basic fibroblast growth factor (bFGF) stimulates the mitogenesis of various cells and plays a key role in wound repair. We studied the immunohistochemical localization of bFGF during wound repair in the rat retina after laser photocoagulation. Methods: Krypton laser photocoagulation was performed on the eyes of pigmented rats. The eyes were enucleated on days 1, 3, 7, 14 and 28 after the photocoagulation, and the immunohistochemical localization of bFGF was assessed. Two different monoclonal antibodies and one polyclonal antibody against bFGF as first antibodies were used. Results: Marked immunoreactivity for bFGF was found in the ganglion cell layer, and weak immunoreactivity for bFGF was found in the retinal pigment epithelial (RPE) cells of the normal adult rat retina. On day 3 after laser photocoagulation, the nuclei and cytoplasm of proliferating RPE cells at the center of the photocoagulated lesion showed intense bFGF immunoreactivity. The nuclei of RPE cells around the lesion showed intense bFGF immunoreactivity. Macrophages that migrated into the lesion showed positive staining for bFGF. These immunoreactivity decreased with time. Controls (0.05 M Tris-HCl buffer, normal serum, or these same antibodies preabsorbed with bFGF) did not show positive staining. Conclusion: The finding of an elevated expression of bFGF immunoreactivity in the photocoagulated lesion suggests that bFGF may play a role in wound repair in the rat retina after laser photocoagulation.     

Relationship between lead concentration in blood and the activities of erythrocyte pyrimidine 5′-nucleotidase and delta-aminolevulinate dehydratase in the mice exposed to lead

The relationship between the activities of both pyrimidine 5-nucleotidase (Py5N) and delta-aminolevulinate dehydratase (ALA-D) in erythrocytes and the concentration of lead in blood was investigated in the mice which were given ad libitum a drinking water containing lead of 10 to 500 ppm, for 30 days.From these results, it was demonstrated that the erythrocyte PySN activity is inhibited by lead and its activity level is negatively correlated with the concentration of lead in blood (r=–0.78). In addition, it was suggested that the erythrocyte Py5N activity is a better indicator in the exposure to relatively high lead concentration while the ALA-D is a more sensitive indicator for evaluating the lead exposure of low and moderate levels.     

Characteristics of epilepsy in severely mentally retarded individuals

In order to clarify the characteristics of epilepsy in patients with severe mentally retarded (SMR) subjects, we analyzed 52 SMR subjects with epilepsy from the institute for SMR subjects at Kikuchi National Hospital, Kumamoto, Japan. A total of 61.5% patients had uncontrolled seizures which were resistant to treatment. The most common combinations of seizure types in those not responding to conventional anticonvulsants were generalized tonic-clonic seizures (GTCS) with tonic seizure and GTCS with atypical absence. Their clinical features were characterized by spastic paralysis associated with a slower background electroencephalogram and abnormal computed tomography scans of the head, suggesting the involvement of cortical damage. These findings suggest that a large proportion of epilepsy in SMR subjects does not respond to treatment and that the severity of organic brain damage may therefore affect the natural course of epilepsy in such patients.     

De novo uterine sarcoma with good response to neo-adjuvant chemotherapy

Abstract.  Numa F, Umayahara K, Ogata H, Nawata S, Sakaguchi Y, Emoto T, Kawasaki K, Hirakawa H, Sase M, Oga A, Kato H. De novo uterine sarcoma with good response to neoadjuvant chemotherapy. We report here the extremely rare case of a 28-year-old woman with advanced stage uterine sarcoma arising soon after a cesarean section. She underwent an abdominal cesarean section because of a breech presentation. At the time of the procedure, there were no abnormal findings such as leiomyoma of the uterus in the abdominal cavity. One year later, she was referred to our hospital because of a large abdominal tumor. Transabdominal power Doppler ultrasonography and magnetic resonance imaging (MRI) showed a large hypervascular tumor in the abdominal cavity. Her serum levels, for the two tumor markers carbohydrate antigen CA125 and LDH, were elevated, at 219 U/ml (< 35 U/ml) and 862 IU/l (115 U/ml−217 U/ml), respectively. On the basis of a diagnosis of malignant tumor of gynecological origin, exploratory laparotomy was performed, and through biopsy, the tumor was found to be advanced undifferentiated uterine sarcoma. She exhibited a good response to neoadjuvant chemotherapy consisting of cisplatin, epirubicin, and dimethyltriazenoimidazole carboxamide (DTIC) every 28 days, which was successfully followed by a hysterectomy.     

Thallium-201 single photon emission tomography of intracranial angiomas

We herein describe thallium-201 single photon emission tomography (T1-201 SPECT) findings in three cases with intracranial angioma. One of the lesions which was associated with chronic encapsulated intracerebral hematoma showed moderate accumulation of T1-201, but, others demonstrated no accumulation. The usefulness and limitations of T1-201 SPECT in differential diagnosis of intracranial mass lesions are discussed.