A novel female-specific member of the CYP3A gene subfamily in the mouse liver

Expression of a female-specific CYP3A in the adult mouse liver was observed on immunoblotting analysis. To characterize this cytochrome P450, we determined the primary structure of its cDNA and examined its expression profile. This cytochrome P450 consisted of 504 amino acids and showed 92, 68, 88, and 69% amino acid sequence identity with mouse CYP3A11, 3A13, 3A16, and 3A25, respectively, and was designated as CYP3A41, a new mouse CYP3A gene. In the female liver, levels of CYP3A41 mRNA expression were comparable to those of CYP3A11, the major CYP3A enzyme in the adult mouse liver. Expression of CYP3A41 mRNA was detected immediately after birth in the livers of animals of both sexes, but increased with age in females, whereas it was gradually reduced in males, resulting in predominantly female-specific expression in livers. Lesser amounts of CYP3A41 mRNA were detected in the kidneys of female mice, with traces in the stomach, ovary, and heart of female mice and in the testis of male mice. Gonadectomy and sex hormone treatment indicated that estradiol and testosterone were able to induce and suppress the expression of CYP3A41 mRNA in the liver, respectively. Among the classical CYP3A inducers, dexamethasone, rifampicin, and 3-methylcholanthrene did not affect the level of CYP3A41 mRNA in the liver of either sex. On the other hand, pregnenolone 16alpha-carbonitrile and phenobarbital suppressed CYP3A41 level to half that of untreated female mice. These observations indicated that CYP3A41 is a female-specific CYP3A and one of the major CYP3A forms in the female mouse liver.     

Fractionation and Phenol Composition of Cellulose Cigarette Smoke Condensate

Fractionation of smoke condensate and a detailed analysis of phenols in the cellulose cigarette smoke were performed during the course of systematic compositional studies of the smoke. Nearly equal yields of phenolic, acidic and neutral fractions were obtained in fractionation of cellulose cigarette smoke condensate. Thirtyseven phenols were newly identified in the smoke of cellulose cigarette in addition to six phenols ever found in pyrolysis products of cellulose. Semi-quantitative determination of some of these phenols revealed that dihydric phenols, such as catechol, hydroquinone, resorcinol and their alkyl derivatives were the main phenols and monohydric phenols were the minor phenols.     

Postoperative irradiation after reconstructive surgery: comparative study of radiosensitivity between free-skin grafts and skin flaps

Radiation effects after reconstructive surgery (free-skin grafts and skin flaps) were studied in the rat, and the optimum time for irradiation was determined. The radiosensitivity of both free-skin grafts and skin flaps showed the same trend depending on time of irradiation after operation. The grafts or flaps irradiated in the hypervascular stage showed severe reactions to irradiation, whereas those irradiated in the hypovascular stage showed milder reactions in gross and microangiographic observation. Vascular damage should be given primary consideration when deciding the proper time for irradiation after reconstructive surgery. In general, free-skin grafts showed more severe reactions than skin flaps, especially in the grafts irradiated in the early stage after operation. The experimental results of this study cannot be readily transferred to a clinical setting, but they suggest that postoperative irradiation could be begun 3 to 4 weeks after operation with respect to graft or flap survival, and the results of the clinical cases almost coincide with these experimental results.     

A Carboxy-Terminally Truncated Human CPSF6 Lacking Residues Encoded by Exon 6 Inhibits HIV-1 cDNA Synthesis and Promotes Capsid Disassembly

Since HIV-1 replication is modulated at multiple stages by host cell factors, identification and characterization of those host cell factors are expected to contribute to the development of novel anti-HIV therapeutics. Previous studies showed that a C-terminally truncated cytosolic form of cleavage and polyadenylation-specific factor 6 (CPSF6-358) inhibits HIV-1 infection through interference with HIV-1 trafficking to the nucleus. Here we identified and characterized a different configuration of C-terminally truncated human CPSF6 (hCPSF6-375) through cDNA expression cloning coupled with ganciclovir-mediated lethal selection. Notably, hCPSF6-375, but not mouse CPSF6-358 (mCPSF6-358) as previously reported, remarkably interfered with viral cDNA synthesis after HIV-1 infection. Moreover, we found that hCPSF6-375 aberrantly accelerated the disassembly of the viral capsid in target cells, while CPSF6-358 did not. Sequence comparison of CPSF6-375 and CPSF6-358 cDNAs showed a lack of exon 6 and additional coding sequence for 54 amino acid residues in the C terminus of hCPSF6-375. Mutational analyses revealed that the residues encoded by exon 6, but not the C-terminal 54 residues in hCPSF6-375, is responsible for impaired viral cDNA synthesis by hCPSF6-375. This is the first report demonstrating a novel mode of HIV-1 inhibition by truncated forms of CPSF6 that involves rapid capsid disassembly and inhibition of viral cDNA synthesis. These findings could facilitate an increased understanding of viral cDNA synthesis in light of the viral capsid disassembly.     

Pyrolysis of Chlorogenic Acid and Rutin

Chlorogenic acid and rutin, major polyphenols in tobacco, were pyrolysed with a furnace type pyrolyser connected directly to a gas Chromatograph and 22 compounds (including catechol, benzoic acid, 4-vinylcatechol and quinic acid γ-lactone) from chlorogenic acid and 24 compounds [including catechol, 5-methyl-2-furaldehyde, 4-methylcatechol and 1,6-anhydroglucopyranose (levoglucosan)] from rutin have been identified as pyrolysis products. The gas Chromatograph was also replaced by a capillary cold trap which allowed collection of the pyrolysis products prior to a quantitative determination using an internal standard. Comparison of the pyrolysis products produced from chlorogenic acid or rutin with those derived from tobacco and analysis of the pyrolysis products from a mixture of tobacco and chlorogenic acid or rutin indicated that fairly large proportions of catechol, 4-vinylcatechol and quinic acid γ-lactone produced by the pyrolysis of tobacco may originate from endogenous chlorogenic acid.     

Relationships between the amount of saliva and medications in elderly individuals

Gerodontology 2010; doi: 10.1111/j.1741‐2358.2009.00358.x
Relationships between the amount of saliva and medications in elderly individuals Objective: To investigate medications that are related to volume of saliva in the elderly. Background data: In the elderly, many cases of mouth dryness may represent side effects of medication. Materials and methods: The volume of unstimulated saliva was measured for 30 s (cotton roll test), and with stimulation for 3 min (gum test) in 368 subjects 79–80 years old (177 men, 191 women). Medications were investigated using subject’s medication notebooks. Results: Mean volumes of unstimulated and stimulated saliva were 0.14 ± 0.13 and 4.30 ± 2.54 ml respectively. Significant differences were seen between gender and mean volume of saliva. The volume of unstimulated saliva was 0.16 ± 0.15 ml for men and 0.11 ± 0.10 ml for women. The volume of stimulated saliva was 4.99 ± 2.67 ml for men and 3.67 ± 2.25 ml for women. The percentage of subjects taking medication was 64.7% (238/368). Mean number of medications was 2.08 ± 2.26, with no significant difference with gender (2.01 ± 2.37 for men, 2.16 ± 2.16 for women). In a stepwise multiple regression analysis with volume of saliva as the objective variable and number of drugs by category as explanatory variables, significant explanatory variables in addition to gender and number of medications were blood‐coagulating agents, Ca antagonists and peptic ulcer drugs for volume of unstimulated saliva, and diabetes medications and peptic ulcer drugs for volume of stimulated saliva. Conclusion: These findings suggest that differences exist between gender in volume of saliva for elderly individuals, and that the volume of saliva is affected by the number and type of medications.     

Ligand specificity determined by differentially arranged common ligand-binding residues in bacterial amino acid chemoreceptors Tsr and Tar

Escherichia coli has closely related amino acid chemoreceptors with distinct ligand specificity, Tar for l-aspartate and Tsr for l-serine. Crystallography of the ligand-binding domain of Tar identified the residues interacting with aspartate, most of which are conserved in Tsr. However, swapping of the nonconserved residues between Tsr and Tar did not change ligand specificity. Analyses with chimeric receptors led us to hypothesize that distinct three-dimensional arrangements of the conserved ligand-binding residues are responsible for ligand specificity. To test this hypothesis, the structures of the apo- and serine-binding forms of the ligand-binding domain of Tsr were determined at 1.95 and 2.5 Å resolutions, respectively. Some of the Tsr residues are arranged differently from the corresponding aspartate-binding residues of Tar to form a high affinity serine-binding pocket. The ligand-binding pocket of Tsr was surrounded by negatively charged residues, which presumably exclude negatively charged aspartate molecules. We propose that all these Tsr- and Tar-specific features contribute to specific recognition of serine and aspartate with the arrangement of the side chain of residue 68 (Asn in Tsr and Ser in Tar) being the most critical.