CD81 nucleotide mutation in hepatocellular carcinoma and lack of CD81 polymorphism in patients at stages of hepatitis C virus infection

Mechanisms determining the chronicity or the pattern of clinical course of hepatitis C virus (HCV) infections have not been clarified. Recently, CD81 was reported to bind the E2 protein of HCV and was suggested to function as a cellular receptor for HCV. Accordingly, the hypothesis was examined that CD81 polymorphism, if it exists, might correlate with certain clinical courses of HCV infection. CD81 cDNA sequences were determined from peripheral blood mononuclear cells (PBMCs). Twenty-four Japanese subjects were enrolled initially as follows: patients with chronic hepatitis C without cirrhosis (n = 3), patients with cirrhosis (n = 3), patients with cirrhosis complicated by hepatocellular carcinoma (HCC) (n = 3), patients with persistent HCV viremia without ALT elevation (n = 3), those with positive anti-HCV antibodies without evidence of HCV viremia (n = 3), and healthy volunteers (n = 9). In all PBMCs samples analyzed, no polymorphism was found in the CD81 cDNA sequence. The sequence was different, however, from the one reported previously at three nucleotide positions: a transversion to thymine instead of cytosine at nt 1130, a deletion at nt 1206, and a guanine insertion at nt 71. Subsequently, CD81 cDNA sequences from PBMCs and HCC tissue were compared among the other 6 patients with chronic hepatitis C bearing HCC. A comparative study of the CD81 sequences from HCC and PBMCs revealed that various nucleotide mutations existed only in the HCC samples in 3 out of 6 patients. Several mutations in the 3' non-coding region of CD81 cDNA were observed exclusively in HCC tissue suggesting its possible role in hepatocarcinogenesis. Because of the absence of polymorphisms, however, CD81 is unlikely to affect the progression of chronic hepatitis C in terms of chronicity, hepatitis activity, or disease stage.     

Memory impairment associated with a dysfunction of the hippocampal cholinergic system induced by prenatal and neonatal exposures to bisphenol-A

One of the most common chemicals that behaves as an endocrine disruptor is the compound 4,4′-isopronylidenediphenol, called bisphenol-A. In the previous study, we reported that exposure to bisphenol-A induced the abnormality of dopamine receptor functions in the mouse limbic area, resulting in a supersensitivity of drugs of abuse-induced pharmacological actions. The present study was undertaken to investigate whether prenatal and neonatal exposures to bisphenol-A could alter other behavioral abnormalities such as anxiogenic behavior, motor learning behavior, or memory. In the present study, adult female mice were chronically treated with bisphenol-A-admixed powder food from mating to weaning. All experiments were performed using male pups. Here we found that prenatal and neonatal exposures to bisphenol-A failed to induce anxiogenic effects and motor-learning impairment using the light-dark test, elevated plus maze test, and rota-rod test. On the other hand, we found that prenatal and neonatal exposures to bisphenol-A induced the memory impairment using the step-through passive avoidance test. Immunohistochemical study showed the dramatic reduction in choline acetyltransferase-like immunoreactivity, which is a marker of acetylcholine (ACh) production, in the hippocampus of mice prenatally and neonatally exposed to bisphenol-A. These results suggest that chronic exposures to bisphenol-A could induce the memory impairment associated with the reduction in ACh production in the hippocampus.     

Mechanomyography of the human quadriceps muscle during incremental cycle ergometry

The mechanical activity of the human quadriceps muscle during maximal incremental cycle ergometry was investigated by mechanomyography (MMG). MMG and surface electromyography (EMG) recordings of vastus lateralis muscle activity were obtained from nine males. Cycle ergometry was performed at 60?rev/min and work load was incremented step wise by 20?W (3.2?Nm) every minute until volitional fatigue. The mean amplitudes of MMG (mMMG) and EMG (mEMG) during the contraction phase were calculated from the last six contractions in each load. The duration, load and work rate of exercise at exhaustion were 13.3 (1.6)?min, 44.1 (5.5)?Nm, 276.7 (34.7)?W, respectively. A linear relationship between mMMG and load was evident in each subject (r?=?0.868–0.995), while mEMG seemed to dissociate as the load became greater. In the grouped mean data, mMMG was linearly related to load whether aligned to the absolute (r?=?0.995) or maximal (r?=?0.995) load. Involvement of the noise component was further investigated by studying passive cycling by four subjects. Pedals were rotated passively for the first half of each stage (PAS) and the subject then pushed the pedals for the second half (ACT). In the lighter load region, the mMMG of ACT was as small as that of PAS. However, the change in the mMMG of PAS was very small compared with that of ACT. In conclusion, this study demonstrates a linear relationship between the mMMG of the quadriceps muscle and work load during maximal incremental cycle ergometry. The effect of movement noise was thought to be small and stable.     

Effects of sleep on pain-related somatosensory evoked potentials in humans

We investigated effects of sleep on pain-related somatosensory evoked potentials (SEP) following painful electrical stimulation of the left index finger. The biggest advantage of this method is that signals ascending through both A-beta fibers relating to touch and A-delta fibers relating to pain can be recorded simultaneously. While the subject was awake, non-painful stimulation evoked early- and middle latency components, N20, P30 and N60, at the C4 electrode, and painful stimulation evoked not only early- and middle latency components at the C4 but also later pain-specific components, N130 and P240, at the Cz electrode. During sleep, N20 and P30 did not show a significant change in amplitude, N60 showed a slight but significant amplitude reduction, and N130 and P240 significantly decreased in amplitude or disappeared, as compared with those while awake. Therefore, we speculate on the mechanisms generating each component as follows; (1) N20 and P30 are the primary components generated in SI ascending through A-beta fibers. (2) N60 is the secondary component generated in SI involving cognitive function to some degree. (3) N130-P240 are the pain-specific components ascending through A-delta fibers, and closely related to cognitive function, because they were much affected by consciousness, different from the components ascending through A-beta fibers.     

Heterotopic gastric mucosa of the small intestine in laboratory beagle dogs

Out of the 365 young laboratory beagle dogs which were used in 17 toxicity bioassays, 15 cases (4.1%) were diagnosed as having congenital heterotopic gastric mucosa of the small intestine. Its incidence in the male dogs (12 cases out of 187) was higher than in the female dogs (3 cases out of 178). Grossly, the lesions were seen as an ulcerous focus of the small intestine, 25 cm to 88 cm proximal to the ileocecal valve. All of the lesions were quite similar histologically and electron microscopically to the normal gastric mucosa, which are composed of the surface mucous cells, chief cells, parietal cells, mucous neck cells and basal granulated cells of the stomach. And consequently, they were considered to be that of a congenital heterotopic tissue in the small intestine. The only morphological characteristic of these lesions different from the regular gastric mucosa was an association with the tubular structure seen in the basal region of these mucosal layers. These cells were considered to be of mucous-secreting cell origin because of secreting type III mucous evident from paradoxical concanavalin A or periodic acid Schiff stains. They seemed to be protecting the surrounding intestinal mucosa from gastric acid.     

Kinetic studies on the reaction of formaldehyde with diphenyl sulfide. Formaldehyde resins. 99

Kinetic studies on the acid-catalyzed reaction of formaldehyde with diphenyl sulfide (DPS) were carried out in acetic acid in the presence of sulfuric acid. The rate of the initial stage of the reaction was found to be in agreement with the following equation. The relative rates of diphenyl sulfide and its homologous compounds in the reaction with formaldehyde gave a good correlation with BROWN -OKAMOTO 's σ^⊕ values and a large ρ value. The polar effects of substituents of the substituted diphenyl sulfides on the rates were found to be considerably large. From these results a plausible mechanism of the reaction has been deduced.     

Appearance of prolactin-releasing peptide-producing neurons in the area postrema of adrenalectomized rats

Prolactin-releasing peptide (PrRP) was found to be a novel hypothalamic peptide that stimulates prolactin release in vitro and in vivo. In the normal adult rat brain, PrRP neurons are known to be located in only three areas, i.e. the dorsomedial hypothalamic nucleus, ventrolateral reticular formation; and nucleus of the tractus solitarius in the medulla oblongata. These PrRP neurons project neurites into various brain areas, including regions such as the paraventricular nucleus, supraoptic nucleus, and bed nucleus of the stria terminalis. Both PrRP nerve fibers and a high level of PrRP receptor, UHR-1, mRNA are observed in the area postrema (AP),but no PrRP neurons are detected in the AP of normal rats. In this study, we clearly demonstrated that PrRP-producing cells newly appeared in the AP of adrenalectomized rats by in situ hybridization and immunocytochemistry. Our results suggest that PrRP may have some important roles in the AP of adrenalectomized rats. This is the first report demonstrating the appearance of PrRP-positive cells in the AP.     

Variations in the core region of hepatitis C virus genomes in patients with chronic hepatitis

Summary In each infected patient, the population of hepatitis C virus is composed of quasispecies that differ in their nucleotide sequences. Among regions in hepatitis C virus genomes, nucleotide sequences of the hypervariable region have been shown to change quickly during the course of infection. It is not known, however, whether these variations exist in the core region that has recently been suggested to contain human lymphocyte antigen class 1 restricted sites for cytotoxic T cell recognition. To clarify this, RNA was extracted from the plasma of four patients with chronic hepatitis C. After cDNA synthesis, DNA fragments that contain the core region were amplified by the polymerase chain reaction and the diversity of the core region was analyzed by the single strand conformation polymorphism analysis. Using this method, single or multiple DNA bands were observed in each patient, and representative bands showed different nucleotide sequences. Comparison of single strand conformation polymorphism patterns revealed that the population of quasispecies changed during the course of chronic infection. These changes were more remarkable in patients with high serum alanine aminotransferase levels than those with low serum alanine aminotransferase levels. Thus, sequential variations exist in the core region of hepatitis C virus in same individuals, and the population of quasispecies as determined by the sequence of the core region changes during the course of infection, which might be related to cytopathic effects of hepatitis C virus.