The distribution of binding sites for centromere protein B (CENP-B) is partly conserved among diverged higher order repeating units of human chromosome 6-specific alphoid DNA

We previously reported the isolation of alphoid satellite clones from a human genomic library using a DNA immunoprecipitation with centromere protein B (CENP-B). Here, we have characterized the distribution of CENP-B-binding sites on the 3-kb BamHI repeats of the cos2 clone. Using in situ hybridization, this alphoid satellite was located primarily at the centromeric region of chromosome 6. The functional binding sites were mapped by precipitating the restriction fragments with recombinant CENP-B in vitro. One repeat (2B3-11) consisted of 19 copies of alphoid monomer, eight of which possessed the binding sites, while another (2B3-9) consisted of 18 copies of the monomer, seven of which possessed the binding sites. The distribution of the sites was well conserved between them, except for the terminus. A similar analysis with the remaining 6-kb region suggested the presence of a continuous 1-kb region with regular spacing of EcoRI sites and the CENP-B-binding sites. When the nucleotide sequence of 2B3-11 was compared with that of another chromosome 6-specific alphoid repeat (p308) that had been described previously, this 1-kb region was highly conserved between them. The distribution of the CENP-B binding sites and the order of alphoid monomers might define the folding of alphoid repeats in the centromeric region.This revised version was published online in November 2005 with corrections to the Cover Date.     

Kinetics of hepatic transport of 4-methylumbelliferone in rats. Analysis by multiple indicator dilution method

Hepatic elimination of 4-methylumbelliferone (4MU), which has been used as a model compound for conjugative metabolism, was studied by means of a multiple indicator dilution (MID) method in the isolated perfused rat liver. Using this method, three intrinsic hepatic clearances, CL _int,inf , CL _{int,eff, and} CL _{int,seq, which represent the influx, efflux, and sequestration processes, respectively, were obtained. When the dose was increased from a low dose (50 g/rat liver) to a high dose (3000 g/rat liver), the hepatic availability of 4MU increased from 0.11 to 0.73. With increasing dose, the} CL _{int,eff value increased approximately two times, while the} CL _{int,seq value decreased to approximately one-third. The remarkable dose dependence of hepatic availability was due to nonlinearity in both} CL _{int,eff and} CL _{int,seq values. However, the} CL_int,inf value was almost independent of dose. The dose-dependent change in CL_int,seq might be explained by the saturation of conjugative metabolism of 4-MU, while the increase in the CL _{int,eff value with increasing dose might be partly explained by the nonlinear tissue binding of 4-MU, since the tissue unbound fraction determined by an ultrafiltration method using liver homogenate increased approximately 1.5 times at higher concentration of 4-MU compared to that at lower concentrations. In addition, based on a comparison of the individual intrinsic clearances, i.e.}, CL _int,inf , CL _{int,eff, and} CL _{int,seq, the major determining process of the apparent hepatic intrinsic clearance of 4MU is thought to be the sequestration process at the high dose. However, at the low dose, the membrane transport process (influx and efflux processes) as well as the sequestration process also determine the apparent hepatic intrinsic clearance}.     

A simulation study on the effect of a uniform diffusional barrier across hepatocytes on drug metabolism by evenly or unevenly distributed uni-enzyme in the liver

The effect of a uniform diffusional barrier on hepatic extraction of the parent drug by evenly or unevenly distributed uni-enzyme was quantitatively determined by the present simulation study. Five models of enzymic distribution were defined with regard to the hepatic blood flow path, and the extraction ratios were calculated or simulated under the various conditions of average intrinsic clearances and diffusion clearances across hepatocytes. Differences in the extraction ratios among the five models were evaluated by the "relative extraction ratios," which are the extraction ratios in each model divided by that in the model where the enzymatic activity is evenly distributed. It was found that when a diffusion clearance was high compared to the intrinsic clearance, enzymic distribution was not an important determinant of the extent of hepatic extraction. By contrast, when a diffusional barrier across hepatocytes exists, i.e., the diffusion clearance is low or intermediate compared to the intrinsic clearance, extraction ratios differed widely among the models of enzymic distribution, especially at intermediate average intrinsic clearances. In the presence of a diffusional barrier, the more skewed the distribution of the enzymatic activity is, the lesser the amount of drug eliminated at steady state. The most efficient metabolism occurred when the enzymatic activity was evenly distributed.     

Bacillus thuringiensis associated with faeces of the Kerama-jika,Cervus nippon keramae,a wild deer indigenous to the Ryukyus,Japan

Faeces of the Kerama-jika (Cervus nippon keramae), a wild shika deer indigenous to the Ryukyus, Japan, were examined for the natural occurrence of Bacillus thuringiensis. Of the ten faecal samples tested, seven contained this organism. The frequency of B. thuringiensis was 8.5% among 387 colonies of spore-forming bacteria belonging to the Bacillus cereus/B. thuringiensis group. Of 33 B. thuringiensis isolates recovered, only one isolate, assigned to the serotype H3abc (serovar kurstaki), exhibited dual toxicity against larvae of the silkworm, Bombyx mori, and the mosquito, Aedes aegypti. All of 32 other isolates were serologically untypable or untestable, and were non-toxic to larvae of the two insect species.     

HTLV-I uveitis in a rabbit

An animal model of HTLV-I associated uveitis was created. One rabbit developed bilateral uveitis 3,5 years after being injected with blood from an HTLV-I-infected rabbit. The proviral DNA of HTLV-I was detected by polymerase chain reaction and dot-blot hybridization in the aqueous humor of the anterior chamber and the vitreous body. Histopathological examination revealed marked corneal opacity with neovascularization and infiltration of inflammatory cells, mainly plasma cells, into the iris, ciliary body, and choroid. Complicated cataracts were also seen. The retinas were destroyed and replaced by gliosis. This is the first animal model of HTLV-I-associated disease to be reported.     

Natural frequency/damping coefficient relationship of the catheter-manometer system required for high-fidelity measurement of the pulmonary arterial pressure

Using a digital simulation method, we analyzed the relationship between natural frequency (f _n ) and damping coefficient () of the catheter-manometer system required for high-fidelity measurement of the pulmonary arterial pressure. The pulmonary artery pressure waveform was obtained with a catheter-tip transducer and it was fed into a dynamic simulator programmed on a computer. The original waveform and the output of the simulator were compared and judged visually for the fidelity. From this analysis, the combination of f _n and was obtained and was plotted on a f _n – diagram. It showed as an area, which was convex on the left side and open on the right side. The left-convex endpoint was located at a damping coefficient of about 0.7. At a lower heart rate, this area was extended to the lower frequency side, while, at a higher heart rate, this area was limited to the higher frequency side. The f _n – diagram was also constructed theoretically by calculating the relations between natural frequencies and damping coefficients of a second order system with the amplitude and phase error tolerance set at +/–5% respectively.(Kinefuchi Y, Suzuki T, Takiguchi M, et al.: Natural frequency/Damping coefficient relationship of the catheter-manometer system required for high-fidelity measurement of the pulmonary arterial pressure. J Anesth 7: 419--426, 1993)     

Estimation of physiologic ability and surgical stress (E-PASS) as a new prediction scoring system for postoperative morbidity and mortality following elective gastrointestinal surgery

(Received for publication on Oct. 25, 1997; accepted on July 7, 1998)     

Cholinergic-drug induced sicca syndrome in Parkinson's disease: a case report and a review of the literature

A 67-year-old woman developed severe sicca manifestations after initial treatment of Parkinson’s disease with an anti-cholinergic drug, which prompted us to look for the presence of Sjögren’s syndrome. The results of sialography, labial salivary gland biopsy, Rose–Bengal test as well as the presence of antinuclear antibody were consistent with the diagnosis of Sjögren’s syndrome. The sicca symptoms diminished by cessation of the anti-cholinergic drug, and the parkinsonian features were controlled by levodopa. We suggest that Sjögren’s syndrome should be considered, if patients with Parkinson’s disease complain severe xerostomia.