Functionality of chimeric Rev proteins of HIV/SIV

Studies on functional compatibility of various Rev proteins derived from all known human and simian immunodeficiency virus subgroups have shown that this essential gene product is not always exchangeable among the viruses. In an attempt to map the region of Rev proteins responsible for the observed nonreciprocal complementation, hybrid genomic Rev expression vectors were constructed by exchanging the first and second exons ofrev genes, and were examined for their abilities to activate reporter clones by transfection. With one exception, the second coding exon ofrev gene determined the functional specificity of Rev proteins.     

Induced circular dichroism of biphenyl and its derivatives in mesophase

The mesophase induced circular dichroism (CD) of biphenyl and its derivatives was investigated using the Tween 80 (monooleate of the ether of sorbitan with 4 mol of polyethyleneglycol)-water system, which can form a twisted smectic mesophase. The sign of CD bands in this mesophase is explained by a modified C₂-symmetry rule, since it can be considered that alignment of the solute molecules in this mesophase can be elucidated in terms of a pseudo-C₂ symmetry, when the concentration of the solute is comparatively high. The assignments of the electronic transitions of the solute molecules show a good accordance with results of magnetic circular dichroism study.     

Multiple epithelial cysts of the spleen and on the splenic capsule, and high serum levels of CA19-9, CA125 and soluble IL-2 receptor

An 18-year-old woman with abdominal pain was diagnosed as having splenic cysts by computed tomography scan. She had high serum levels of CA19-9 (2886.8 U/mL; normal value, <35 U/mL), CA125 (131.1 U/mL; normal value, <35 U/mL) and soluble IL-2 receptor (1490 U/mL; normal range, 220-530 U/mL). The resected spleen weighed 1050 g, was 14 x 28 cm, and had more than 10 macroscopic cysts up to 10.3 x 9.5 cm. There were numerous microscopic cysts in the spleen and several on the splenic capsule. The levels of CA19-9 and CA125 in the cyst fluid were 2165550 U/mL and 160400 U/mL, respectively. After the surgery, the serum levels of the tumor markers decreased gradually. The inside of the largest cyst was mainly covered by granulation tissue with a focal lining of epithelial cells, and the other macroscopic cysts had stratified squamous epithelium. The microscopic splenic cysts and cysts on the splenic capsule were lined by either attenuated single-layered or multilayered epithelial cells. The lining epithelial cells of these cysts were positive for epithelial membrane antigen and cytokeratins. CA19-9 and CA125 were detected in the lining cells of the splenic cysts. In the present case, it is suspected that the splenic cysts were derived from the capsular lining cells that showed migration from the capsule or formed microcysts on the splenic capsule, as in the case of ovarian inclusion cysts.     

Identification of tissue-embedded ascarid larvae by ribosomal DNA sequencing

Polymerase chain reaction (PCR) was applied to identify tissue-embedded ascarid nematode larvae. Two sequences of the internal transcribed spacer (ITS) regions of ribosomal DNA (rDNA), ITS1 and ITS2, of the ascarid parasites were amplified and compared with those of ascarid-nematodes registered in a DNA database (GenBank). The ITS sequences of the PCR products obtained from the ascarid parasite specimen in our laboratory were compatible with those of registered adult Ascaris and Toxocara parasites. PCR amplification of the ITS regions was sensitive enough to detect a single larva of Ascaris suum mixed with porcine liver tissue. Using this method, ascarid larvae embedded in the liver of a naturally infected turkey were identified as Toxocara canis. These results suggest that even a single larva embedded in tissues from patients with larva migrans could be identified by sequencing the ITS regions.     

Functional evaluation of lung by Xe-133 lung ventilation scintigraphy before and after lung volume reduction surgery (LVRS) in patients with pulmonary emphysema

We evaluated the respiratory functions of patients with pulmonary emphysema who underwent lung volume reduction surgery (LVRS) by the mean transit time (MTT) with Xe-133 lung ventilation scintigraphy, forced expiration volume in 1 sec (FEV1.0), residual volume (RV), distance walked in 6 min (6-min walk), and the Hugh-Jones classification (H-J classification) before and after LVRS. In 69 patients with pulmonary emphysema (62 men, 7 women; age range, 47-75 years; mean age, 65.4 years +/- 6.1, preoperative H-J classification, III (two were II)-V) who underwent LVRS, all preoperative and postoperative parameters (MTT 3 weeks after LVRS and the others 3 months after LVRS) were judged statistically by the Wilcoxon signed-ranks test and Odds ratio. Every postoperative parameter was improved with a significant difference (P < 0.05) compared to preoperative parameters. MTT at 3 weeks after LVRS was not associated with %FEV1.0 and the H-J classification at 3 months after LVRS, but was associated with RV and a 6-min walk at 3 months after LVRS. MTT was useful for the clinical evalution of aerobic capability after LVRS.     

Isolation,characterization and chromosomal mapping of an actin gene from the primitive red alga Cyanidioschyzon merolae

Based on the results of cytological studies, it has been assumed that Cyanidioschyzon merolae does not contain actin genes. However, Southern hybridization of C. merolae cell-nuclear DNA with a yeast actin-gene probe has suggested the presence of an actin gene in the C. merolae genome. In the present study, an actin gene was isolated from a C. merolae genomic library using a yeast actin-gene probe. The C. merolae actin gene has no intron. The predicted actin is composed of 377 amino acids and has an estimated molecular mass of 42003 Da. Southern hybridization indicated that the C. merolae genome contains only one actin gene. This gene is transcribed at a size of 2.4 kb. When Southern hybridization was performed with C. merolae chromosomes separated by pulsed-field gel electrophoresis, a band appeared on unseparated chromosomes XI and XII. A phylogenetic tree based on known eucaryote actin-gene sequences revealed that C. merolae diverged after the division of Protozoa, but before the division of Fungi, Animalia and Chlorophyta.     

Anesthetic induction agents, sympathetic nerve activity and baroreflex sensitivity: a study in rabbits comparing thiopental, propofol and etomidate

The mechanisms of arterial hypotension following intravenous anesthetic induction agents are multifactorial. The purpose of this study was to evaluate and compare the effects of thiopental, propofol and etomidate on hemodynamics, sympathetic outflow and arterial baroreflex sensitivity using not only neuraxis-intact but also totally baro-denervated rabbits. A total of 60 rabbits was anesthetized with urethane, tracheotomized, and mechanically ventilated with oxygen in nitrogen (FiO2 0.5). The left renal sympathetic nerve was isolated and placed on a bipolar electrode to record renal sympathetic nerve activity (RSNA). Thirty animals underwent a surgical preparation of total baroreceptor denervation. Bolus injections of an anesthesia induction dose of thiopental 4 mg/kg and twice the induction dose of propofol 4 mg/kg significantly decreased RSNA to the same extent (19.4+/-6.7 and 19.7+/-5.2% reduction, mean +/- SEM) and mean arterial pressure (MAP) also to the same extent (19.5+/-4.6 and 22.1+/-3.1% reduction) in the neuraxis-intact animals. RSNA was increased (34.5+/-6%) without reduction of MAP by an induction dose of etomidate, 0.3 mg/kg. Sympathetic barosensitivity was attenuated even 10 min after thiopental at 4 mg/kg or propofol at 4 mg/kg (68% and 54% of control, respectively). Propofol at 2 mg/kg (induction dose) and etomidate at 0.6 mg/kg decreased RSNA and MAP only in the baro-denervated animals. It was found from the barosensitivity study that patients can be hemodynamically unstable even though blood pressure has returned to normal after thiopental and propofol administration. Data suggest that etomidate can even stimulate the sympathetic nervous system and increase sympathetic outflow. It was also clearly found from the baro-denervated animal study that thiopental was stronger than propofol in directly suppressing sympathetic outflow at the induction dose.     

Effects of endurance training on myosin heavy-chain isoforms and enzyme activity in the rat diaphragm

We investigated the effects of endurance training (20 m/min, 60 min/day, 5 days/week) on myosin heavy-chain (MHC) isoforms and succinic dehydrogenase (SDH) activity in rat crural and costal diaphragms, and plantaris muscles. Although the 4-week endurance training produced significant (P<0.05) increases, both in SDH activity and the percentage of isoform HCIIa in the plantaris of the trained rat compared with the sedentary control rat, these alterations did not occur in either the crural or costal diaphragms. After 10 weeks of endurance training, trained animals had significantly (P<0.05) higher SDH activity in the costal diaphragm and the plantaris. Moreover, a significant (P<0.05) decrease occurred in the percentage of HCIIb in the costal diaphragm, and a significant (P<0.01) decrease in the percentage of HCIIb concomitant with a significant (P<0.05) increase of HCIIa resulted in the plantaris. However, the crural diaphragm did not show any significant changes after 10 weeks of endurance training. These results indicate that endurance training induces an alteration in the expression of an MHC phenotype, in addition to causing an increase in oxidative enzyme activity. However, the alterations in response to endurance training are apparently not uniform, varying between regions and/or kinds of muscles.     

Nucleotide sequence of the gene encoding the matrix protein of mumps virus (Miyahara strain)

The nucleotide sequence of the gene encoding the matrix (M) protein of mumps virus (MuV), Miyahara strain, has been determined from several overlapping cDNA clones. The M protein mRNA is 1248 nucleotides in length, exclusive of the poly(A) tail, and codes for a protein of 375 amino acids (Mr41,556). Comparison of the deduced amino acid sequence of the M protein of the Miyahara strain with that of the SBL-1 strain revealed that the M proteins of both strains are highly conserved. A significantly lower rate of nucleotide differences conducive to amino acid differences in the M gene compared with other genes appeared to indicate the importance of the conserved primary structure of the M protein for its function.Requests for reprints should be addressed to Kiyoshi Tanabayashi, Department of Measles Virus, National Institute of Health, 4-7-1 Gakuen, Musashimurayama, Tokyo 190-12, Japan.