Single-beat determination of Doppler-derived aortic flow measurement in patients with atrial fibrillation.

The clinical assessment of left ventricular systolic function in patients with atrial fibrillation is unreliable and difficult because of beat-to-beat variation. We initially evaluated an index that is on the basis of the ratio of preceding R-R (RR1) to pre-preceding R-R (RR2) intervals (RR1/RR2) for the measurement of Doppler aortic flow (peak flow velocity [Vp] and time-velocity integral [TVI] proportional to stroke volume) in 20 patients (aged 65 +/- 9.6 years) with atrial fibrillation. We obtained each parameter for >13 cardiac cycles, and the relationship between each parameter at a given cardiac beat and the RR1/RR2 ratio were evaluated by linear regression analysis. The value of each parameter at RR1/RR2 = 1 was calculated from the equation of linear regression line and compared with measured average value over all cardiac cycles. Both parameters showed a significant positive correlation with the RR1/RR2 ratio (Vp, r = 0.98, y = 1.01x + 0.61; TVI, r = 0.99, y = 1.01x + 0.26). The calculated value of each parameter at RR1/RR2 = 1 was quite similar to the average value (Vp, 97.4 +/- 30.8 vs 95.7 +/- 29.8 cm/s; TVI, 17.7 +/- 6.8 vs 17.3 +/- 6.7 cm, respectively). In the additional 20 patients (aged 77.4 +/- 15.2 years), Doppler aortic flow parameters of a single beat with identical RR1 and RR2 intervals were compared with measured average value over all cardiac cycles and showed similar results (Vp, r = 0.99, y = 0.99x + 3.4, P <.0001, bias -0.5 cm/s; TVI, r = 0.99, y = 0.92x + 1.5, P <.0001, bias 0.1 cm). In conclusion, the Doppler aortic flow at RR1/RR2 = 1 allows the left ventricular systolic parameters to be accurately evaluated during atrial fibrillation and obviates the less reliable process of averaging multiple irregular beats.     

Contrast-enhanced dynamic MR imaging parameters and histological types of invasive ductal carcinoma of breast.

The diagnosis of breast cancer has progressed owing to the improvement of both MRI equipments and MR techniques. CE-MRI is expected to be more useful for diagnosis of the existence and characteristics of breast cancer than mammography and ultrasound. Forty-three breast cancer patients, who underwent breast MRI examination before surgery and had histologically confirmed invasive ductal carcinomas, were included in this study. In 19, seven and 17 of them, carcinomas were histologically classified as papillotubular, solid-tubular, and scirrhous type, respectively. In dynamic MRI studies, the MR parameters were calculated from the signal intensity determined before and at five time-points after a bolus of 0.1 mmol Gd-DTPA/kg in the chosen region of interest (ROI). The differential analysis of MR parameters with reference to histopathology was performed by one-way analysis of variance (ANOVA) in dynamic studies. Four of 15 parameters analyzed, ENH1-2, ENH1, MSLP, and SAT3, were significantly different between papillotubular and scirrhous carcinoma. The dynamic curve of papillotubular carcinoma reached a maximum in the very early phase and then decreased slowly (linear pattern), while that of scirrhous carcinoma peaked in the slightly later phase and then decreased (parabolic pattern). In the differential analysis by Kruskal-Wallis test, although no significant differences were found in any morphological parameters among three histological types, spicula formation and rim enhancement tended to appear comparatively frequently in scirrhous and solid-tubular carcinoma. CE-MRI might reveal the differences of growth characteristics among different histological types of breast carcinomas and provide a diagnostic method useful for estimation of the prognosis of breast cancer.     

Current status of genetic study on affective disorder

A series of studies have indicated the existence of genetic predisposition and the polygenic-multifactorial mode of transmission for bipolar disorder(BPD). Linkage studies have defined several BPD susceptibility loci. The findings to date suggested the candidate regions on 4p16, 12q23-24, 18p11, 18q22, 21q22, Xq24-27 for BPD, although no genes has yet been definitively identified. There are also many reports on the analyses of candidate genes, using association studies. But none of gene polymorphisms have been established as firm disease alleles with sufficient replications. Novel statistical methods and development of new strategies are necessary to approach the goal of isolating susceptibility genes.     

Encephalitis induced in non-human primates by canine distemper virus adapted to human neural cells

The Onderstepoort strain of canine distemper virus (CDV) adapted to human oligodendroglioma, neuroblastoma and glioblastoma cells, was intracerebrally inoculated into cynomolgus monkeys. All the three viruses caused periventricular encephalitis involving the brain stem. When the neurovirulence of these viruses were compared in terms of clinical signs and histopathological changes, the oligodendroglioma-adapted virus showed the neurovirulence of the highest degree inducing degeneration of axons and glial cells. Chronic encephalitis was also observed. The neuroblastoma-adapted virus induced predominantly nerve-cell degeneration although clinically this virus showed slightly lower degree of neurovirulence than the oligodendroglioma-adapted viruses. The glioblastoma-adapted virus showed clinically much lower neurovirulence than the other two viruses; all monkeys infected with this virus survived and produced high level of antibody in most cases. Histopathologically degeneration of axons and glial cells was characteristics although the incidence was less frequent than the oligodendroglioma-adapted virus. Predominant involvement of nerve cells by neuroblastoma-adapted virus and predominant involvement of axon and glial cells by oligodendroglioma-adapted virus and by glioblastoma-adapted virus suggest that in vitro tropism of the virus to neural cells is partially reflected on tropism of the virus in the CNS.     

Clinico-pathological analysis of foal diseases from 237 autopsy cases.

To elucidate the current status of foal diseases in Japan, clinico-pathological analysis was conducted on 237 foal autopsy cases. As a result, bacterial infection was identified as an important cause of foal death. Most of the bacteria isolated from these cases were ubiquitous, opportunistic, environmental organisms, known to be non-pathogenic to mature animals. Most of cases with bacterial infection were diagnosed as having hypogammaglobulinemia, i.e., failure of passive transfer. In addition, the mean weight of thymuses in foals affected by bacterial infection tended to be lower than that of foals without infection. These findings suggest that the common cause of foal diseases were mainly due to the opportunistic bacterial infections associated with the weakened immune function, serving as precursor to or promotor of infection.     

Activation in the premotor cortex during mental calculation in patients with Alzheimer's disease: relevance of reduction in posterior cingulate metabolism

In vivo brain imaging of people with Alzheimer's disease (AD) has suggested the presence of functional disintegration in the posterior-anterior brain network from the posterior cingulate cortex (PCC) to the prefrontal cortex. To investigate the relationship between the baseline posteromedial metabolism and prefrontal neural activity during cognitomnemonic tasks in AD patients, we measured both glucose metabolism at baseline and cerebral blood flow (CBF) during the execution of mental calculation tasks (serial number subtraction) in 10 early-stage AD patients and six healthy subjects. The present study employed positron emission tomography with (18)F-fluorodeoxyglucose and H(2)(15)O. Group comparison using the region-of-interest (ROI) method and voxel-based statistical parametric mapping (SPM99) showed significant reduction in glucose metabolism in the PCC of the AD group. The PCC metabolism in the AD group was negatively correlated with scores on the Mini-Mental State Examination and with correct responses to the arithmetic task. During the arithmetic task, regional CBF increased significantly in the left parietal and bilateral prefrontal cortices in the normal group, whereas the bilateral premotor cortices were significantly activated in the AD group. Regression analysis showed a significant inverse correlation between the premotor activation and the baseline PCC metabolism in the AD group. These results suggest that the premotor cortex plays a compensatory role in executing mental calculations in AD patients with reduced posteromedial functions, which might reflect the dynamic aspect of the pathophysiology of early AD.     

Pro-inflammatory chemokine IL-8 in gastroesophageal reflux disease

Recent reports have demonstrated significantly higher expression levels of interleukin-8 (IL-8) in patients with gastroesophageal reflux disease (GERD) including non-erosive reflux disease (NERD). The levels of IL-8 mRNA expression were significantly decreased after proton pump inhibitor. The esophageal expression of CINCs, rat IL-8-like chemokines, was markedly enhanced in the models of acute or chronic esophagitis in rats. The production of IL-8 from esophageal mucosal cells was enhanced by the exposure to bile acid. These results suggest that IL-8 chemokine may play a major role in the pathogenesis of esophageal inflammation in GERD.