Optical imaging of glycinergic inhibition in the vestibular and cochlear nuclei

Using multiple-site optical recording techniques, the spatiotemporal activity was observed in both the cochlear and vestibular nucleus in newborn mice. The optical responses were obviously enhanced by bath-applied strychnine. A quantitative analysis showed higher enhancements to occur in the cochlear nucleus than in the vestibular nucleus. Optical imaging enables us to visualize the spatiotemporal extent of the inhibitory receptive field after the application of strychnine.     

Multiple-site optical recording of mouse brainstem evoked by vestibulocochlear nerve stimulation

We used optical imaging to investigate the mouse cochlear and vestibular nucleus in brainstem slices using a voltage-sensitive dye, RH 155. As a result, the spatiotemporal patterns of excitatory propagation were shown. These optical signals consisted of two components consisting of a spike-like fast signal and a long-lasting slow signal. All responses were abolished by tetrodotoxin. The slow signals were eliminated under a Ca(2+)-free solution. In addition, synaptic fatigue was also observed. The present study indicated the feasibility of optical recording for visually revealing the synaptic transmission in both the vestibular and cochlear nucleus.     

No allelic loss at the p53 locus in 1,2-dimethylhydrazine-induced mouse colon tumors: PCR-SSCP analysis with sequence-tagged microsatellite site primers

We examined allelic loss in colon tumors induced by 1,2-dimethylhydrazine(DMH) in F1 hybrid mice, using sequence-tagged microsatellitesite (STMS) primers derived from the chromosomal region closelylinked to the p53 locus. Polymerase chain reaction-single-strandconformation polymorphism (PCR-SSCP) analysis of 155 colonictumors with two STMS markers revealed that no genetic alterationshad occurred in these tumors, except for one case where oneof the markers detected an increase of one CA repeat unit inone allele. No allelic loss at the loci closely linked to thep53 locus strongly suggests that allelic loss at the p53 locusis not involved in DMH-induced colon carcinogenesis in mice.     

Genetic Changes and Histopathological Grades in Human Hepatocellular Carcinomas

Loss of heterozygosity (LOH) on chromosomes 1p, 4q, 5q, 8p, 13q, 16q, 17p, and 22q, and mutation of the p53 gene were simultaneously analyzed in 63 hepatocellular carcinomas (HCCs) with distinct histopathological grades, 80% of the tumors being from patients who had been exposed to hepatitis B virus (HBV) or hepatitis C virus (HCV). The frequencies of LOH on 8 chromosomes were 0–25% in 10 well differentiated HCCs, LOH being observed on 4q, 5q and 17p, 21–53% in 26 moderately differentiated HCCs, LOH on 8p and 17p being high, and 29–75% in 27 poorly differentiated HCCs, LOH on 17p, 4q and 8p heing the most frequent. p53 gene mutation was detected in moderately and poorly differentiated HCCs at 15% and 52%, respectively, but not at all in well differentiated HCCs. Of the mutations detected, 42% were transition mutation and only 5% were CpG transition, in contrast to the high frequencies of these types of mutations in colon tumors (78% and 54%, respectively). LOH on every chromosome and p53 mutation were more frequent in more advanced tumors, and accumulation of genetic changes increased with increase of the histopathological grade. Frequency of genetic changes in HCCs from HBV-positive patients was comparable to that from HCV-positive patients. The present results suggest that accumulation of genetic changes in multiple tumor suppressor genes, especially LOH on 17p, 4q and 8p, and mutation in p53 gene, are involved in the progression of liver cancer, and LOH on 17p and 4q precedes other genetic changes. Differences in the direction of p53 mutation between HCC and colon carcinoma suggest that liver carcinogens are distinct from colon carcinogens. Furthermore, mechanisms affecting the frequency of LOH in HCCs in HBV-infected patients may be similar to those in HCV-infected patients.     

Immunosuppressive-associated encephalopathy in bone marrow transplant recipients]

We studied clinical features of immunosuppressive (cyclosporine, tacrolimus) associated encephalopathy in bone marrow transplant patients. 378 cases of allogeneic bone marrow transplant recipients over fifteen years old of chronic and acute leukemia (CML, ANLL, ALL) (n = 311), myelodysplastic syndrome (MDS) (n = 42) and severe aplastic anemia (SAA) (n = 25) were investigated. Immunosuppressive associated encephalopathy occurred in 12 cases. The rate of incidence was significantly higher in SAA and MDS (7 cases) than in leukemia. The cases which showed typical radiological abnormality in MRI were limited in SAA and hypoplastic MDS. 10 cases died, which revealed worse than an overall survival rate of recipients without immunosupressive-associated encephalopathy. 5 of 7 cases in SAA and MDS had taken cyclosporine as treatment of the disease before bone marrow transplantation and that might influence the incidence of encephalopathy.     

Vasculitic condition following instillation of epirubicin hydrochloride in an outpatient chemotherapy

The appearance of vasculitis is often observed following the use of epirubicin hydrochloride in outpatients. As it is important to continue to provide a safe treatment for outpatient with little or no side effects, the aim of this study was to reveal causes underlying the outbreak of vasculitis or the vasculitic state of patients who had undergone instillation of epirubicin hydrochloride as an adjuvant therapy following a breast cancer surgery. The study was conducted based on past investigation records. We extracted relevant factors such as age, previous illness, physical condition and dosage of epirubicin hydrochloride from past records which may all be connected to the outbreak of vasculitis. We administered one dose of epirubicin hydrochloride that was diluted into 50-100 ml of normal saline solution or 5% glucose and instilled over a period of 30 minutes. As a result of this instillation of epirubicin hydrochloride, 35 out of 45 cases displayed vasculitis. We did not observe any relationship among the aged (over 60), previous illness or physical condition (BMI over 25) and the appearance of vasculitis. When a dosage amount of more than 110 mg of epirubicin hydrochloride was administered, 23 out of 29 cases displayed vasculitis. From the past records, it was observed that the cause of vasculitis was dependent on the administrative method itself. As previous studies reported that vasculitis was low when epirubicin hydrochloride was retained in blood vessels for only a short time, our study, however, concentrated on how to administer epirubicin hydrochloride. Our results suggested that an adoption of a single dosage system may suppress the outbreak of vasculitis.     

Smoke inhalation injury: diagnosis and respiratory management

Smoke inhalation is a significant comorbid factor following major thermal injury. Smoke exposure is only a trigger for the sequence of events responsible for the development of inhalation injury. Noxious chemicals generated by incomplete combustion injure the exposed bronchoepithelium and stimulate the release of chemical mediators that cause a progressive inflammatory process. Airway inflammation and pulmonary edema impair gas exchange and increase the susceptibility to pulmonary infection. Earlier diagnosis and treatment of inhalation injury is an important element to improve the clinical course of severe burn patients. The American Burn Association, however, recently concluded that there are insufficient data to support a treatment standard for the diagnosis of inhalation injury. At present, the diagnosis of inhalation injury is supported by the combination of history, physical examination, bronchoscopy, and laboratory findings For accurate diagnosis of inhalation injury, helical CT scanning and examination to detect activated leukocytes in bronchoalveolar lavage fluid may be warranted. In the respiratory management of inhalation injury, repeated removal of pseudomembrane by fiberoptic bronchoscopy and the use of adequate PEEP to avoid airway obstruction are essential. High-frequency percussive ventilation can be a suitable mode of ventilation for inhalation injury.     

Oral contraceptives and uterine peristalsis: evaluation with MRI

PURPOSE: To evaluate the effects of oral contraceptives (OCs) on uterine contractility using cine MRI, and correlate the kinematic findings with the static findings. MATERIALS AND METHODS: Healthy female volunteers of reproductive age (23 taking OCs, and 15 not) were evaluated at mid-cycle. MR images were obtained with a 1.5T magnet, with 60 serial images taken every three seconds by half-Fourier acquisition single-shot turbo spin echo (HASTE) to be displayed in cine mode. Assessments were based on the 1) detectability of uterine peristalsis in cine mode, 2) peristaltic frequency and direction, 3) thickness of the endometrium, myometrium, and junctional zone (JZ) on T2-weighted images (T2WIs), and 4) intensity of the myometrium and cervical mucus on T2WIs and T1-weighted images (T1WIs), respectively. RESULTS: Uterine peristalsis was markedly decreased in the OC users. The endometrium and JZ were significantly thinner, and the myometrium was thicker in the OC users compared to controls. The signal intensity of the myometrium and cervical mucus was significantly higher in the OC users than in controls. CONCLUSION: OCs markedly suppressed uterine peristalsis at mid-cycle, and the uterus displayed a globular configuration with a thin JZ that may be related to decreased uterine peristalsis in OC users.     

Explicit knowledge and intention to learn in sequence learning: an event-related potential study

The present study was performed to examine how intention to learn and explicit knowledge in sequence learning are reflected in event-related potentials. Participants responded to numerals presented in a repeating order, which were replaced infrequently by deviant numerals. The participants were given incidental or intentional learning instructions. Sequence parts for which they acquired explicit knowledge were identified for each participant by post-task memory tests. Reaction times indicated that sequence learning occurred under both types of instruction. The N2 enhancement for deviants was primarily associated with explicit sequence knowledge, and the P3 enhancement showed a weak association. These results suggested that N2 and P3 reflect different aspects of explicit learning.