A case of malignant peritoneal mesothelioma with a good response to treatment

A rare case of malignant peritoneal mesothelioma in a 49-year-old Japanese woman is presented. The tumor was limited to the peritoneum, and was cytologically and histologically identified as being composed of two components, epithelial and non-epithelial forms. The transition in her CA-125 level suggested that this tumor had good prospects of developing into a malignant mesothelioma. The good prognosis of the patient is considered to be attributed to detecting this tumor in its early stage and to aggressive chemotherapy.     

Effects of repeated testing on the incidence of haloperidol-induced catalepsy in mice

Effects of repeated testing on the incidence of haloperidol-induced catalepsy were investigated in mice. The incidence of catalepsy, evaluated with the forelimbs or hindlimbs placed on a standard horizontal bar, increased in three successive tests in mice injected with haloperidol. Catalepsy was not provoked by repeated testing in animals with saline. In a subsequent study, mice were examined for catalepsy in the forelimbs in the first two trials and then in the hindlimbs. In this procedure, the incidence of catalepsy did not increase with repeated testing. These results suggest that repeated testing increases the incidence of haloperidol-induced catalepsy but does not influence the cataleptogenic potency of the drug.     

ENDOSCOPIC MANAGEMENT OF A DIEULAFOY‐LIKE LESION IN A DUODENAL DIVERTICULUM

We present a 70‐year‐old man who had two episodes of melena during the preceding 8‐year period. He had a Dieulafoy‐like lesion in a diverticulum in the third portion of the duodenum. While emergency endoscopy revealed neither apparent blood nor clots around the diverticular orifice, there was a non‐bleeding vessel in the fundus of the diverticulum. The vessel ceased bleeding after argon plasma coagulation and, since then, the patient has not experienced bleeding. In cases of gastrointestinal bleeding of obscure origin, duodenal diverticulum should be considered as a possible source of bleeding, even when endoscopy discloses no apparent bleeding.     

Prefrontal cerebral activity during a simple “rock, paper, scissors” task measured by the noninvasive near-infrared spectroscopy method

We conducted a noninvasive near-infrared spectroscopy (NIRS) study using the game of rock, paper, scissors (RPS) as a simple neurocognitive task for the prefrontal cortex (PFC) in 15 healthy volunteers. We employed an opposite “to lose” RPS task coupled with a normal “to win” RPS task, since the former requires inhibition of behavior, one of the most important functions of the prefrontal cortex. During the NIRS examination, subjects had to present one of the three RPS hands in response to hands displayed randomly on a computer screen every 1.5 s, and were required to show hands that lose to the computer, or that beat the computer. We measured the relative concentrations of oxyhemoglobin (oxy-Hb) using the prefrontal probes of the NIRS system during the tasks. The increases in oxy-Hb during the “to win” RPS task were small, but were quite large and laterally dominant during the “to lose” RPS task. The difference between the two tasks might have been due to the participants’ cognitive conflict with losing on the RPS. We conclude that losing is better than winning on the RPS as a sensitive indicator in the NIRS examination of PFC.     

Hypertrophy of medial globus pallidus and substantia nigra reticulata in 6‐hydroxydopamine‐lesioned rats treated with L‐DOPA: Implication for L‐DOPA‐induced dyskinesia in Parkinson's disease

The medial globus pallidus plays a crucial role in generation of L‐DOPA‐induced dyskinesia in patients with Parkinson's disease. The 6‐hydroxydopamine‐lesioned rat exhibiting behavioral sensitization to L‐DOPA is one useful animal model for examining L‐DOPA‐induced dyskinesia. To determine neuropathological abnormality responsible for behavioral sensitization, the medial globus pallidus and the substantia nigra reticulata in 6‐hydroxydopamine‐lesioned rats treated with L‐DOPA were examined. Intermittent L‐DOPA treatment induced hypertrophy of the lesioned‐side of medial globus pallidus and substantia nigra reticulata of 6‐hydroxydopamine‐lesioned rats with behavioral sensitization to L‐DOPA. Additionally, coadministration of a 5‐HT_1A receptor agonist, 8‐hydroxy‐2(di‐n‐propylamino)tetralin with L‐DOPA, alleviated the hypertrophy with improvement of the behavioral sensitization. These results suggest that hypertrophy of the medial globus pallidus and substantia nigra reticulata is associated with induction of behavioral sensitization to L‐DOPA in 6‐hydroxydopamine‐lesioned rats. Therefore, neuropathological changes corresponding to hypertrophy might underlie L‐DOPA‐induced dyskinesia in patients with Parkinson's disease.