Heme-copper oxidase family structure of Magnetospirillum magnetotacticum 'cytochrome a1'-like hemoprotein without cytochrome c oxidase activity

The genes encoding 'cytochrome a1'-like hemoprotein of Magnetospirillum magnetotacticum were identified and sequenced. Three ORFs, mcalI, mcaI and hosA, were included in the sequenced region. The six histidine residues which were predicted to associate with the prosthetic cofactors of heme-copper oxidase superfamily were conserved in the hemoprotein. However, none of the amino acid residues which were proposed to participate in the oxygen-reducing and the coupled proton pumping reactions in cytochrome c oxidase were at all conserved in the hemoprotein.

Femtochemistry

The topic of femtochemistry is surveyed from both theoretical and experimental points of view. A time-dependent wave packet description of the photodissociation of the O---C---S molecule reveals vibrational motion in the transition-state region and suggests targets for direct experimental observation. Theoretical approaches for treating femtosecond chemical phenomena in condensed phases are featured along with prospects for laser-controlled chemical reactions by using tailored ultrashort chirped pulses. An experimental study of the photoisomerization of retinal in the protein bacteriorhodopsin is discussed with an aim to gain insight into the potential energy surfaces on which this remarkably efficient and selective reactions proceeds. Finally, a prospective view of new frontiers in femtochemistry is given.

Effects of phase changes on reflection and their wavelength dependence in optical profilometry

The method as well as an appropriate instrumentation for measuring phase changes of reflected light is described. The phase changes on samples of Au, Al, Ag, and Cr evaporated films are measured for five wavelengths (lambda) from 442 to 633 nm, with respect to the phase change at the glass-air interface, where it should be zero. The measured results for the Au film are in fairly good agreement with values calculated by use of optical constants from a handbook or the complex refractive index measured by an ellipsometer. The phase changes for Al and Ag films are different from calculated values by ~5 degrees or a shift length of 4.4 nm at lambda = 633 nm, while those of the Cr film show large shifts as high as 16 degrees or a shift length of 9.8 nm at lambda = 442 nm.

[Polychlorinated biphenyls (PCBs) and polychlorinated quaterphenyls (PCQs) concentrations in skin surface lipids and blood of patients with Yusho]

The relationship between Polychlorinated Biphenyls (PCBs), and Polychlorinated Quaterphenyls (PCQs) concentrations in the skin surface lipids and blood was investigated in twenty two patients with PCB poisoning (Yusho) and 9 control subjects were analyzed. The collection of skin surface lipids was performed by the method of cotton pad with 70% ethyl alcohol. The alkaline decomposition method described as "the official standard analytical methods for the isolation of PCBs and PCQs fractions" was used. In the blood of control group, the mean value of PCBs concentration was 1.8 ng/g, and that of PCQs concentration was very low and undetectable by our analytical method. On the other hand, the PCBs concentration in the Yusho group was three times higher than those in the control group. The mean value of PCQs concentration was 1.90 ng/g in Yusho group, while it was not detectable in the control group. In the skin surface lipids of patients with Yusho, the mean value of PCBs concentration was 668.6 ng/g, but was 256.7 ng/g in the control group. The mean value of PCQs concentration in the skin surface lipids of Yusho patients was 35.4 ng/g, although it was not detected in the control group. These values of the skin surface lipids in 1993 were decreased as compared with those in 1992. PCBs and PCQs levels in the skin surface lipids were higher than those in the blood. These findings suggests that cutaneous sebaceous system is one of the excretory systems of polyhalogenated chemicals, such as PCBs or PCQs, when these chemicals are precipitated in human or mammalian.

Serum and urinary N-acetyl-beta-D-glucosaminidase activity among the inhabitants of a rural area in Japan--the effect of age and hypertension

In this paper, the normal values, distribution, and variations in serum and urinary activities of the lysosomal enzyme, N-acetyl-beta-D-glucosaminidase (NAG), were estimated in a rural area of Japan. The frequency distribution of NAG activities both in the serum and urine of 1,152 males and females (aged 35 to 87), living in a rural area of Gifu Prefecture in Japan, showed an approximately log-normal distribution. Geometric mean values (with S.D. ranges) in healthy subjects (876 males and females) were 12.61 U/l (9.56-16.63) for serum NAG and 8.05 U/l (4.03-16.07) for urinary NAG. There was no significant difference between those of males and females. Serum and urinary NAG activities increased with advancing ages, and these NAG activities in hypertensive subjects were higher than those in normotensives. Since the serum and urinary levels of several commonly measured cytosolic chemicals were within normal limits, the above results could not be ascribed to tissue necrosis. Thus, the estimation of serum and urinary NAG could be a useful indicator discriminating the essential hypertensive patients from the normal subjects.

Molecular characteristics and physical state of human papillomavirus DNA change with progressing malignancy: studies in a patient with epidermodysplasia verruciformis

In order to establish the role of human papillomavirus (HPV) in carcinogenesis of epidermodysplasia verruciformis (EV), the presence, the molecular characteristics and the physical state of HPV DNA in a benign lesion, a primary carcinoma and a metastatic carcinoma developing in the same EV patient were studied and compared. Of the 2 HPV DNAs isolated from benign macular lesions, only one (a subtype of HPV 5) was detected in both primary and metastatic tumors. Only one normal species of viral DNA molecule was detected in the benign lesion, whereas most, if not all, viral DNA molecules present in the carcinoma (both primary and metastatic) were aberrant ones. The major viral DNA molecule in the primary carcinoma was a large HPV DNA with duplicated 40% subgenomic segments, and was present as free episomes. The major viral DNA molecule in the metastatic carcinoma was the 40% subgenomic segment itself, lacking the remaining 60% segment of the viral genome, and was integrated within cellular DNA. Thus, HPV DNA was present in tumors at any stage of malignancy, and its molecular characteristics and physical state changed not only with the development but also with the enhancement of malignancy, consistently conserving its defined 40% subgenomic segment as the predominant viral sequences. Our results suggest that HPV 5 may be actually involved in carcinogenesis in EV patients.

Two human papillomavirus DNAs molecularly cloned from a patient with epidermodysplasia verruciformis: restriction maps

Two distinct human papillomavirus (HPV) DNAs (MY-1 and MY-2) were molecularly cloned from the benign skin lesions of a patient with epidermodysplasia verruciformis. The restriction map of MY-1 was the same as that of HPV 3a. The map of MY-2 appeared to be different from those of any HPVs reported in the literature. MY-2 did not cross-hybridize with MY-1 or the DNAs of HPV types 1, 2 and 4 under stringent conditions.

Primary choriocarcinoma of the lung

Choriocarcinoma was found in the lung of a 34-year-old woman. Examination of the patient's entire body, especially the genital tract, failed to disclose foci of choriocarcinoma other than that in the right lung. After surgery, the levels of human chorionic gonadotropin in the blood and the urine fell. It was concluded that the choriocarcinoma of the lung was, in fact, the primary tumor. The genesis of choriocarcinoma was also studied in ten patients who died after delivery or abortion. Autopsy disclosed trophoblasts in the pulmonary arteries in nine of these ten patients. These findings suggest that primary choriocarcinoma in women is due to pulmonary embolism caused by trophoblasts at the time of abortion or delivery.

Hemangioblastoma of the central nervous system: nature of the stromal cells as studied by the immunoperoxidase technique

Ten hemangioblastomas of the central nervous system were examined by an immunoperoxidase technique for glial fibrillary acidic protein (GFAP), S-100 protein, and Factor VIII-related antigen to determine the origin of the stromal cells. In seven cases scattered stromal cells were positive for GFAP, and eight cases showed variable numbers of S-100 protein-positive cells. These positive cells were present throughout the tumors. S-100 protein-positive stromal cells corresponded to GFAP-positive cells, but the former were more numerous than the latter. Staining for Factor VIII-related antigen was negative in stromal cells, except in endothelial cells lining capillaries. It was suggested that stromal cells of capillary hemangioblastomas are composed by heterogeneous cell populations.

Enterohepatic circulation of clioquinol in the rat

The existence of the enterohepatic circulation (EHC) of clioquinol was confirmed by using paired rats, donor and recipient, which were connected to each other with a bile duct-to-duodenum cannula. The concentrations of clioquinol and its metabolites appearing in the plasma of the recipient following intraduodenal 10 mg/kg dose of clioquinol to the donor were fairly low. However, within 24 h after the administration ca. 12% of the dose was reexcreted in the bile of the recipient as clioquinol glucuronide and ca. 2% in the urine as clioquinol sulfate. From these results and the data of biliary excretion in our previous paper, the glucuronide was found to play a role on the EHC. Further, both in vitro and in situ results suggested that clioquinol glucuronide excreted in the bile may be absorbed partially after return to the parent drug in the intestinal tract and partially as such without deconjugation.

Intestinal absorption and metabolism of clioquinol in the rat

Plasma concentrations of clioquinol and its metabolites after single or repeated oral administration of clioquinol, absorption region of clioquinol in gastrointestinal tract, and intestinal metabolism were studied in rats. Plasma concentrations of clioquinol after oral administration of four different doses (20, 100, 200 and 400 mg/kg) were lower than those of the two metabolites, clioquinol glucuronide and sulfate. Mean maximal plasma concentration of unchanged drug was in the range of 1-8 nmol/ml. Clioquinol was absorbed poorly from the stomach and fairly from the small intestine. Bile was an important route for excretion of clioquinol in rats. The mesenteric venous plasma from the closed intestinal loops of both jejunal and ileal regions was analyzed for clioquinol and the metabolites and it was found that clioquinol glucuronide was formed predominantly in both regions. From the results of the present studies, intestinal metabolism of clioquinol can be pointed out as a major factor for difficulty to cause clioquinol intoxication.

Appearance of intoxication in rats by intraperitoneal administration of clioquinol

The investigation was undertaken to study the neurological symptoms in rats caused by maintaining high plasma concentration of about 30 nmol/ml or more, of clioquinol. Clioquinol suspension which was prepared using polysorbate 80 was administered intraperitoneally to rats and plasma and tissue concentrations were determined. On administration of clioquinol of 100 and 200 mg/kg, the mean plasma concentrations of clioquinol reached maximum values of 30 and 58 nmol/ml, respectively, after 0.5-1 h and thereafter decreased rapidly. With 400 mg/kg, however, plasma concentration reached maximum value of about 75 nmol/ml and fell slowly. By single and repeated administration of the suspension, clioquinol was distributed in the liver and kidney at a high concentration, and also in the nervous system. In experiments on appearance of neurotoxicity in rats by repeated administration of the suspension, all of 10 rats administered intraperitoneally with 100 mg/kg/d did not develop any neurological symptoms for about 30 d. On the other hand, one of 10 and 7 of 13 rats administered with 200 and 400 mg/kg/d, respectively, developed ataxia in the hind legs or all legs on the 3rd to the 12th day after starting administration. Pathologically, a slight change of the peripheral nerve, central chromatolysis of the anterior horn neuron and severe neuronal degeneration of the Ammon's horn were observed in the rats with ataxia.