Inhibitory effects of D2 agonists by striatal injection on excessive release of dopamine and hyperactivity induced by Bay K 8644 in rats

We investigated by means of behavioral and neurochemical studies the effects of either D(1) or D(2) agonist on excessive dopamine release and hyperactivity induced by the microinjection of Bay K 8644, and an L-type Ca(2+) channel stimulant, into the rat caudate putamen under a novel environmental condition. Hyperactivity (locomotor activity and rearing counts) and significant increases in extracellular dopamine levels induced by Bay K 8644 were concomitantly observed. D(1) agonist, SKF81297, administered into the caudate putamen did not block Bay K 8644-induced hyperactivity measured by monitoring both animal activity and increases in extracellular dopamine levels detected by microdialysis. Pretreatment with the D(2) agonists, bromocriptine, talipexole and pramipexole, into the caudate putamen significantly blocked Bay K 8644-induced hyperactivity for 45 min after Bay K 8644 administration, although the single administration of these agonists significantly potentiated locomotor activity and rearing behavior. Furthermore, these agonists significantly suppressed Bay K 8644-induced extracellular dopamine levels. Our results indicate that these D(2) agonists (1) act on postsynaptic neuronal D(2) receptors under conditions of normal or low dopamine release in the caudate putamen, and (2) act on presynaptic D(2) receptors (autoreceptors) when excessive levels of dopamine are released or hyperdopamine neuronal activity is induced. Consequently, the effect of D(2) agonists in the clinical treatment of Parkinson's disease may be due to stimulation of postsynaptic D(2) receptors rather than presynaptic autoreceptors.     

Presynaptic L-type Ca(2)+ channels on excessive dopamine release from rat caudate putamen

We investigated by means of behavioral and neurochemical studies the role of the nerve terminal L-type voltage sensitive Ca(2)+ channel on dopamine (DA) release. Microinjection of Bay K 8644 (BAYK), an L-type Ca(2)+ channel stimulant, into the rat caudate putamen increased locomotor activity and rearing behavior in a dose-dependent manner, whereas injections into the amygdala had no effect. DA receptor antagonists significantly blocked BAYK-induced hyperactivity. Significant increases of extracellular DA levels were detected by microdialysis 20 min after BAYK administration into caudate putamen and then declined. This increase was influenced by tetrodotoxin, an axonal Na(+) channel blocker. Pretreatment with nimodipine and nicardipine, but not nifedipine, which are 1, 4-dihydropyridine L-type Ca(2)+ channel antagonists, administered into the caudate putamen significantly blocked BAYK-induced hyperactivity and DA efflux. These results indicate that the extraordinary DA release in the caudate putamen was mediated by extreme stimulation of the nicardipine and nimodipine-sensitive L-type Ca(2)+ channel present in the nerve terminal of striatal DA neurons.     

Enhancement of S-antigen and its mRNA in the irides of uveitic patients

S-antigen (S-Ag) and its mRNA were analysed by immunohistochemistry and in situ hybridization in 32 iridectomy specimens from 29 uveitic patients and 10 non-uveitic patients. S-Ag was detected in one iris and its mRNA was detected in 12 uveitic patients. Neither S-Ag nor its mRNA was found in the controls (P < 0.003). Ten of the 12 patients who had detectable S-Ag mRNA, while only four of the 17 patients who did not, had received corticosteroids for more than 3 years (P = 0.006). We also demonstrated S-Ag and its mRNA in bovine iris by immunoprecipitation and polymerase chain reaction. These results indicate that S-Ag and its mRNA accumulate in the irides of some uveitic patients. This accumulation may be the result of local immunoregulatory factors and an effect of corticosteroid treatment, and may modulate ocular inflammation.     

Effects of Daily Matcha and Caffeine Intake on Mild Acute Psychological Stress-Related Cognitive Function in Middle-Aged and Older Adults: A Randomized Placebo-Controlled Study

Matcha, a type of green tea, has a higher amino acid content than other types of tea. We previously examined the ability of matcha to improve cognitive function in older adults and determined that continuous matcha intake improves attention and executive function. This study aimed to compare the effects of matcha and caffeine and clarify the differences between these effects. The study was registered at the University Hospital Medical Information Network (UMIN000036578). The effect of single and continuous intake was compared, and the usefulness of continuous intake was evaluated under the stress condition. The Uchida–Kraepelin test (UKT) was used to induce mild acute stress, and the Cognitrax was used to evaluate cognitive function. A single dose of caffeine improved attentional function during or after stress loading. The reduced reaction time in the Cognitrax, observed following a single dose of matcha, was likely due to caffeine. The matcha group showed an increase in the amount of work after continuous intake, whereas the caffeine group only showed an increase in the amount of work for the UKT after a single dose. Ingesting matcha with caffeine improves both attention and work performance when suffering from psychological stress compared with caffeine alone.     

Comparative study of a novel selective urate reabsorption inhibitor “dotinurad” among patient groups with different stages of renal dysfunction

Clinical and Experimental Nephrology - Dotinurad is a selective urate reabsorption inhibitor (SURI), which selectively inhibits URAT1 to lower serum uric acid levels in patients with hyperuricemia....     

Handlebar hernia with intra-abdominal extraluminal air presenting as a novel form of traumatic abdominal wall hernia: Report of a case

An 18-year-old male was admitted to our Emergency Department with a traumatic abdominal wall hernia (TAWH) of the left lower quadrant (LLQ) after suffering hypogastric blunt injury and urogenital lacerations in a motorcycle accident. Upright chest X-ray showed a small amount of right infradiaphragmatic free air, and a computed tomographic (CT) scan demonstrated an abdominal wall hernia. At surgery, no impairment was found in the digestive tract, and an abdominal herniorrhaphy was performed. It is suggested that the free air had passed through a connection between the scrotal laceration and the contralateral abdominal defect via the subcutaneous space and was palpated as emphysema. This is a new type of TAWH, which suggests that blunt abdominal trauma may result in negative pressure in the subcutaneous and peritoneal cavity, and this could reflect the pathophysiology of TAWH.     

Neuroradiologic evaluation of the subdural pathogenesis in infants with small heads

Summary A marginal low density area is often revealed by CT scan in infants with microcephalia. However, it is difficult to assess precisely the main pathologic state of the marginal low density area and also whether such a lesion exists in the subdural-epiarachnoid space or in the subarachnoid space.A carotid antiographic evaluation of cortical vessels in the marginal avascular area was made and suggestive results were obtained.When there is acute subdural effusion or subdural hematoma, cortical arteries in the marginal avascular area will have a straightened and attenuated figure. But when such a pathologic state persists for a long period, it induces secondary cortical atrophy and the subarachnoid space becomes anlarged. The cortical artery appears as if it is flying in the enlarged subarachnoid space because it is detached from the gyrus and the sulcus following the cortical atrophy. This is why we named it the flying artery.Angiographic findings allow more precise interpretation of the marginal low density area in the CT scan.     

Clinical utility of monitoring sialyl Lewis(X) (CD15S) antigen on peripheral lymphocytes for the diagnosis and treatment of rejection after renal transplantation

BACKGROUND: In organ transplantation, the grafts must be carefully monitored, but it is often difficult to make a quick and accurate diagnosis of unusual changes. Extensive research has failed to identify a useful marker for rejection. We investigated the clinical utility of sialyl Lewis(X) (CD15s) monitoring in 17 renal transplant patients with acute rejection. METHODS: The expression of CD15s on peripheral lymphocytes was examined using flow cytometry in renal transplant recipients with rejection (n=17), without rejection (n=23), recipients infected with cytomegalovirus (n=7), recipients with other diseases (n=7), and healthy volunteers (n=18). CD15s expression was compared with histological findings, and was also examined before and after steroid pulse therapy to investigate the effects of steroids on CD15s antigen expression on the surface of the peripheral lymphocytes. RESULTS: CD15s was strongly expressed in all patients with rejection, but was not expressed in any of the patients without rejection or in any healthy volunteers. Histologically, cell infiltration into the rejected graft was moderate or severe in all patients with strong expression of CD15s. In contrast, no or only mild infiltration was observed in patients with weak expression of CD15s. In addition, 14 of 17 patients (14/17, 82%) with strong CD15s expression improved upon administration of steroid pulse therapy, although there was no benefit from steroids in any of the patients with weak expression of CD15s. CONCLUSIONS: The CD15s antigen is expressed strongly on the peripheral lymphocytes at the time of rejection. It is interesting that the efficacy of steroid therapy in the patients with elevated creatinine could be predicted by CD15s expression on the peripheral lymphocytes before graft biopsy. There have been only few reports showing the relationship between CD markers and the efficacy of the treatment in patients with elevated creatinine. We report that the detection of CD15s on the peripheral lymphocytes by flow cytometry was an easy, helpful, and noninvasive means for the diagnosis and treatment of patients with elevated creatinine after renal transplantation.