Significantly increased expression of beta-glucuronidase in the central nervous system of mucopolysaccharidosis type VII mice from the latency-associated transcript promoter in a nonpathogenic herpes simplex virus type 1 vector

Herpes simplex virus (HSV) has the ability to establish life-long latent infections in postmitotic neurons and to remain transcriptionally active, continuously expressing latency-associated transcripts (LAT) while producing minimal disease. These properties have made HSV an excellent candidate for neuronal gene transfer. Previously, we have shown that in mucopolysaccharidosis type VII mice (MPS VII, beta-glucuronidase deficiency) the LAT promoter is capable of expressing beta-glucuronidase (GUSB) in the trigeminal ganglion and the brainstem after latency is established. However, the number of neurons expressing GUSB is much lower than the number expressing 2-kb LAT following a wild-type virus infection. In this study, we have evaluated the effect of the position of the coding sequence relative to the LAT promoter on beta-glucuronidase gene expression in the central nervous system (CNS). Non-neurovirulent (ICP-34.5-deleted HSV-1) vectors were used, allowing direct intracranial injection. Significantly more GUSB activity was detected in brains of MPS VII mice inoculated with a recombinant virus (HSV-LAT-GUSB-JS) in which the GUSB cDNA was inserted near the LAT promoter, compared to viruses where it was inserted farther downstream in either the LAT exon 1 or overlapping exon 1 and the 2-kb LAT intron. This vector produced more than 100 times the number of positive cells than the other constructs. During acute infection, the distribution of viral replication differed from the distribution of GUSB enzyme expression. Viral antigen was predominately present in cells around the site of injection in the caudate putamen and in ependymal cells lining the ventricles. In contrast, GUSB expression was present mainly in cells of the thalamus and hypothalamus, which did not exhibit viral antigen, suggesting that GUSB enzyme activity was expressed from latently but not acutely infected neuronal cells. This vector design should be useful for high-level expression of various genes in the CNS.

Analysis of interaction between molecules of Bombyx mori nucleopolyhedrovirus IE-2 using a yeast two-hybrid system

Baculovirus IE-2 protein is one of well-known transactivators. In this report, we demonstrate that Bombyx mori nucleopolyhedrovirus (BmNPV) IE-2 interacts with itself. Several clones were obtained from a yeast two-hybrid screening system using IE-2 as bait and were found to encode IE-2 protein. Nucleotide sequencing of these clones showed that they contained C-terminal regions in common. Further analyses suggest that BmNPV IE-2 protein interacts with itself through 80 amino acid residues of coiled-coil domain in C-terminus.

[Effect of radiotherapy on penetration of 5-FU in blood-pancreatic barrier in rats]

OBJECTIVE

To investigate the effect of radiotherapy dose on penetration of 5-FU (5-fluorouracil) in blood-pancreatic barrier in rats.

METHODS

After the pancreatic region of the rats were irradiated by 2, 10, 20, 30 and 40 (Gy) doses of gamma-ray, we investigated the penetration ratio (PR) of 5-FU in the pancreatic tissue with HPLC assay.

RESULTS

When treated with low-dose of gamma-ray (2 Gy), the PR of 5-FU increased obviously after 8 hours. But in the high-dose groups (>/= 10 Gy), the PR was less than or had no difference with control group. At the same time, we found that the islets had appeared pathological degeneration, while the pancreatic lobular structure, acini and ducts had no visible changes in 20 Gy group.

CONCLUSIONS

After the treatment of low-dose of gamma-ray combined with 5-FU, the effect of chemoradiotherapy may be improved for enhanced PR of 5-FU in pancreatic tissue, and at the same time, chemotherapy and radiotherapy cooperate with each other. But in high dose groups (>/= 10 Gy), radiotherapy may reduce the effect of chemotherapy in acute phase. After high-dose radiotherapy, we should pay attention to the change of glucose-resistance of patient to reduce the incidence of radiotherapy complication.

Overexpression of proenkephalin in the amygdala potentiates the anxiolytic effects of benzodiazepines

To elucidate the role of opioid peptides in control of the anxiety-like behavior and anxiety-reducing actions of benzodiazepines, a recombinant, replication-defective herpes virus (SHPE) carrying human preproenkephalin cDNA was delivered to rat amygdala. Viral infection resulted in a strong, localized transgene expression after 2-4 days which diminished after one week. Anxiety-like behavior and the anxiolytic effect of diazepam were assessed three days after gene delivery using the elevated plus maze test. While SHPE infection alone did not reduce anxiety-like behavior, rats infected with SHPE exhibited a greater response to the anxiolytic effect of diazepam when compared to rats infected with a control virus (SHZ.1) containing the lacZ gene. The enhancement of diazepam action by SHPE was naloxone reversible, region-specific, and correlated with the time course of preproenkephalin expression. The findings implicate amygdalar opioid peptides in regulating the anxiolytic effects of benzodiazepines. This study also demonstrates the usefulness of recombinant herpes virus in evaluating the role of single gene products within specific brain sites in pharmacological responses and complex behaviors.

Identification of a novel 0.7-kb polyadenylated transcript in the LAT promoter region of HSV-1 that is strain specific and may contribute to virulence

Herpes Simplex virus expresses latency-associated transcripts (LATs) the function of which remains obscure despite increasing knowledge of their structure and expression. Upstream of the LAT coding region is a region of the genome that is poorly characterized although it lies in an area that is responsible for modulation of reactivation efficiency in two different animal models. Transcript mapping with strains 17, McKrae, KOS, and F has revealed strain differences in this region of the viral genome. Strain 17 and McKrae expressed a novel polyadenylated 0.7-kb transcript that is absent from KOS and F. This transcript is expressed in the LAT direction and has the kinetics of a true late gene during the lytic cycle of infection. A deletion mutant, 17DeltaBsa, which does not express the 0.7-kb RNA, is less virulent than the parental strain 17. A rescuant with F sequence (17DeltaBsa/RF) shows virulence similar to F, whereas a rescuant with strain 17 sequence (17DeltaBsa/R17) is similar to strain 17. Virulence is altered by deletion or substitution in the region encoding the 0.7-kb transcript (BsaI-BsaI); however, reactivation in the mouse explant cocultivation assay or the adrenergically induced rabbit reactivation model remained unchanged. The importance of this region for virulence is discussed.

Treatment of Ota's nevus by Q-switched alexandrite laser : therapeutic outcome in relation to clinical and histopathological findings

Ota's nevus is a dermal melanocytic disease which causes serious cosmetic problems for affected individuals. Recently Q-switched lasers with a pulse duration of 100 nsec or less became available for patient treatment. We evaluated the clinical efficacy of the Q-switched alexandrite laser (755 nm, 100 nsec) in relation to the histopathological findings. Fifty-five Korean patients with Ota's nevus were treated with a Q-switched alexandrite laser for three sessions (7.5 J/cm2) at three month intervals. Skin biopsies were taken in all of the patients before treatment and immediately after treatment in five patients. Clinical effectiveness and side effects were evaluated by direct observation and photographs. Pigment clearing was excellent in 27 patients (49%), good in 17 patients (31%), fair in 7 patients (13%) and poor in 4 (7%) patients. Postinflammatory hyperpigmentation developed in 30 patients (55%) which resolved within four months. But there were no serious complications including scarring or textural change. The therapeutic outcome was not affected by color but by depth of the nevus. Nevi of Ota with depth of 1 mm or less were associated with excellent or good results. Q-switched alexandrite laser is a very effective and safe tool for treating Ota's nevus. Depth of 1 mm or less of dermal melanocytes was a good prognostic marker.

Characterization of baculovirus repeated open reading frames (bro) in Bombyx mori nucleopolyhedrovirus

The baculovirus Bombyx mori nucleopolyhedrovirus (BmNPV) contains five related open reading frames (ORFs). Recent sequence analyses of several other baculovirus genomes reveal that these ORFs belong to a unique multigene family called the baculovirus repeated ORFs (bro) family. Here we have characterized these five genes from BmNPV at the transcriptional and translational levels. Reverse transcription-PCR and primer extension analyses indicated that transcription of all bro genes occurs by 2 to 4 h postinfection (p.i.) and reaches maximal levels between at 8 and 12 h p.i. Transcription of all genes is initiated between 50 and 70 nucleotides upstream of the start codon, at a characteristic C(T)AGT motif. Expression of a cat reporter gene under the control of each bro promoter provides evidence that a viral factor(s) is required for the transcription of all bro genes. Immunoblot analysis indicated that a population of BRO proteins is produced vigorously between at 8 and 14 h p.i. Immunohistochemical analysis by confocal microscopy showed that BRO proteins are localized in both the nucleus and the cytoplasm at 8 h p.i. Four BmNPV mutants, in which the bro-a, bro-b, bro-c, and bro-e genes were individually inactivated, were successfully isolated. However, exhaustive efforts failed to isolate a bro-d-deficient mutant. Similarly, it was not possible to isolate a double-deletion bro-a bro-c mutant. The bro-d gene may play an irreplaceable functional role(s) during viral infection, while bro-a and bro-c may functionally complement each other.

Genetic and antigenic diversity among eastern equine encephalitis viruses from North, Central, and South America

Eastern equine encephalitis virus (EEEV), the sole species in the EEE antigenic complex, is divided into North and South American antigenic varieties based on hemagglutination inhibition tests. Here we describe serologic and phylogenetic analyses of representatives of these varieties, spanning the entire temporal and geographic range available. Nucleotide sequencing and phylogenetic analyses revealed additional genetic diversity within the South American variety; 3 major South/Central American lineages were identified including one represented by a single isolate from eastern Brazil, and 2 lineages with more widespread distributions in Central and South America. All North American isolates comprised a single, highly conserved lineage with strains grouped by the time of isolation and to some extent by location. An EEEV strain isolated during a 1996 equine outbreak in Tamaulipas State, Mexico was closely related to recent Texas isolates, suggesting southward EEEV transportation beyond the presumed enzootic range. Plaque reduction neutralization tests with representatives from the 4 major lineages indicated that each represents a distinct antigenic subtype. A taxonomic revision of the EEE complex is proposed.

Changes in nociceptive and anxiolytic responses following herpes virus-mediated preproenkephalin overexpression in rat amygdala are naloxone-reversible and transient

These results using herpes virus-mediated gene transfer to overexpress enkephalin in the amygdala support the role of amygdalar opioids in the anxiolytic actions of benzodiazepines and supraspinal nociception (see ref. 1). These studies also demonstrate the usefulness of recombinant herpes virus in evaluating the role of single gene products within specific brain sites in pharmacological responses and complex behaviors.

Evaluation of the completeness of cancer case ascertainment in the Seoul male cohort study: application of the capture-recapture method

Since the completeness of case ascertainment is directly related to the validity of a study, the evaluation of completeness is an essential feature of a cohort study. To estimate the completeness of cancer case ascertainment during a three year period (Jan. 1, 1993, to Dec. 31, 1995) in which the Seoul Male Cohort was followed up, we applied capture-recapture method. Data were obtained from the cancer registries, medical records and death certificates, with cases identified from each source numbering 103, 105, and 38, respectively. After eliminating duplicate cases, the total number was 141, and by using a log-linear model, the number of cases not detected by any of the three data sources was estimated to be 16. For all cancers, the estimated completeness of follow-up was 89.9%.

Genetic and fitness changes accompanying adaptation of an arbovirus to vertebrate and invertebrate cells

The alternating host cycle and persistent vector infection may constrain the evolution of arboviruses. To test this hypothesis, eastern equine encephalitis virus was passaged in BHK or mosquito cells, as well as in alternating (both) host cell passages. High and low multiplicities were used to examine the effect of defective interfering particles. Clonal BHK and persistent mosquito cell infections were also evaluated. Fitness was measured with one-step growth curves and competition assays, and mutations were evaluated by nucleotide sequencing and RNA fingerprinting. All passages and assays were done at 32 degrees C to eliminate temperature as a selection factor. Viruses passaged in either cell type alone exhibited fitness declines in the bypassed cells, while high-multiplicity and clonal passages caused fitness declines in both types of cells. Bypassed cell fitness losses were mosquito and vertebrate specific and were not restricted to individual cell lines. Fitness increases occurred in the cell line used for single-host-adaptation passages and in both cells for alternately passaged viruses. Surprisingly, single-host-cell passage increased fitness in that cell type no more than alternating passages. However, single-host-cell adaptation resulted in more mutations than alternating cell passages. Mosquito cell adaptation invariably resulted in replacement of the stop codon in nsP3 with arginine or cysteine. In one case, BHK cell adaptation resulted in a 238-nucleotide deletion in the 3' untranslated region. Many nonsynonymous substitutions were shared among more than one BHK or mosquito cell passage series, suggesting positive Darwinian selection. Our results suggest that alternating host transmission cycles constrain the evolutionary rates of arboviruses but not their fitness for either host alone.

Genetic evidence for the origins of Venezuelan equine encephalitis virus subtype IAB outbreaks

Epizootics of Venezuelan equine encephalitis (VEE) involving subtype IAB viruses occurred sporadically in South, Central and North America from 1938 to 1973. Incompletely inactivated vaccines have long been suspected as a source of the later epizootics. We tested this hypothesis by sequencing the PE2 glycoprotein precursor (1,677 nucleotides) or 26S/nonstructural protein 4 (nsP4) genome regions (4,490 nucleotides) for isolates representing most major outbreaks. Two distinct IAB genotypes were identified: 1) 1940s Peruvian strains and 2) 1938-1973 isolates from South, Central, and North America. Nucleotide sequences of these two genotypes differed by 1.1%, while the latter group showed only 0.6% sequence diversity. Early VEE virus IAB strains that were used for inactivated vaccine preparation had sequences identical to those predicted by phylogenetic analyses to be ancestors of the 1960s-1970s outbreaks. These data support the hypothesis of a vaccine origin for many VEE outbreaks. However, continuous, cryptic circulation of IAB viruses cannot be ruled out as a source of epizootic emergence.

[Studies on the chemical constituents of chloroform extract of Dracaena cochinchinensis]

Six compounds were isolated from Dracaena cochinchinensis (Lour.) S.C. Chen. Their structures were identified as 2,3,5,6-tetracchloro-1,4-dimethoxybenzene (I), 7-hydroxy-4'-methoxyflavan (II), 4'-hydroxy-3,5-dimethoxystilbene (III), 4'-hydroxy-2,6-dimethoxydihydrochalcone (IV), 4'-hydroxy-2,4,6-trimethoxydihydrochalcone (V) and 6-hydroxy-7-methoxy-3-(4'-hydroxybenzyl) chromane (VI) by chemical method and spectral analysis. IV and VI are new compounds.

Identification and characterization of the Cydia pomonella granulovirus cathepsin and chitinase genes

A 3.2 kb BamHI-EcoRI fragment of the Cydia pomonella granulovirus (CpGV) genome was subcloned and characterized. Sequence analysis revealed two complete and one partial open reading frames (ORFs). ORF7L is predicted to encode a 66.7 kDa protein (594 amino acid residues) that is 57% identical (amino acid sequence) to the chiA gene (ORF126) of Autographa californica nucleopolyhedrovirus (AcMNPV), encoding a chitinase. ORF8R is 333 amino acids in length and shows high similarity (between 64% and 67%) with baculovirus cathepsins. The partial ORF, ORF5L, is related to AcMNPV ORF145 of unknown function. Phylogenetic trees were constructed for both chitinase and cathepsin sequences from baculoviruses and other species. In both cases, the baculovirus sequences were monophyletic but with a deep division between the GVs and NPVs, suggesting both genes were present in an ancestral virus prior to the separation of the two genera. However, these studies did not provide definitive evidence for the origin of either protein in baculoviruses. To investigate CpGV cathepsin function, a rescue experiment was performed using a Bombyx mori NPV (BmNPV) mutant (BmCysPD) which lacks a functional cathepsin (cath) gene. Larvae infected with BmCysPD-Cp.cat, a BmCysPD derivative carrying CpGV cath, showed similar symptoms to wild-type BmNPV infected insects, confirming that CpGV cath encodes a functional cathepsin. Primer extension analysis of mRNA from BmCysPD-Cp.cat infected cells showed that CpGV cath transcription was initiated from a consensus late transcription motif (ATAAG) within the CpGV sequences, indicating that a CpGV late promoter motif was recognized in this NPV system.

Herpes virus-mediated preproenkephalin gene transfer to the amygdala is antinociceptive

To evaluate the role of the amygdala in pain modulation and opioid-mediated antinociception, a recombinant, replication-defective herpes virus carrying the human preproenkephalin cDNA was injected bilaterally into the rat amygdala. Four days after gene delivery nociceptive behavior was assessed by the formalin test. Rats infected with the virus expressing preproenkephalin showed a selective, naloxone-reversible abolition of phase 2 flinching behavior compared to rats infected with a control virus. The results implicate the amygdala in the control of pain and in opioid analgesia and demonstrate the use of recombinant herpes viruses as tools for studying gene function in specific neural pathways of the central nervous system.

Crash simulations of wheelchair-occupant systems in transport

A nonlinear multirigid body dynamic computer model has been developed to simulate the dynamic responses of a wheelchair-occupant system in a vehicle during a crash. The occupant, restrained by safety belts, is seated in a wheelchair that is, in turn, tied down in a vehicle. Validated extensively by crash sled tests at three laboratories, this model has been used to predict the responses of wheelchair-occupant systems in various crash environments. To evaluate the crashworthiness of different wheelchair tie-downs, the sensitivity of several design parameters, such as tiedown stiffness, wheel stiffness, and tiedown positions, has been studied using this model, and optimal values of these parameters for the wheelchair-occupant system have been obtained. Moreover, the model has been used to study the sensitivity of crash sled test pulse corridors in an effort to develop a sled test standard. It has been found that an existing ISO corridor allows large variation and should be "tightened." The model was implemented using a version of the multibody dynamic simulator, the Articulated Total Body program.

Repeated emergence of epidemic/epizootic Venezuelan equine encephalitis from a single genotype of enzootic subtype ID virus

Venezuelan equine encephalitis (VEE) epidemics and equine epizootics occurred periodically in the Americas from the 1920s until the early 1970s, when the causative viruses, subtypes IAB and IC, were postulated to have become extinct. Recent outbreaks in Columbia and Venezuela have renewed interest in the source of epidemic/epizootic viruses and their mechanism of interepizootic maintenance. We performed phylogenetic analyses of VEE virus isolates spanning the entire temporal and geographic range of strains available, using 857-nucleotide reverse transcription-PCR products including the E3 and E2 genes. Analyses indicated that epidemic/epizootic viruses are closely related to four distinct, enzootic subtype ID-like lineages. One of these lineages, which occurs in Columbia, Peru, and Venezuela, also included all of the epidemic/epizootic isolates; the remaining three ID-like lineages, which occur in Panama, Peru, Florida, coastal Ecuador, and southwestern Columbia, were apparently not associated with epizootic VEE emergence. Within the Columbia/Peru/Venezuela lineage, three distinct monophyletic groups of epidemic/epizootic viruses were delineated, indicating that VEE emergence has occurred independently at least three times (convergent evolution). Representative, complete E2 amino acid sequences were compared to identify potential determinants of equine virulence and epizootic emergence. Amino acids implicated previously in laboratory mouse attenuation generally did not vary among the natural isolates that we examined, indicating that they probably are not involved in equine virulence changes associated with VEE emergence. Most informative amino acids correlated with phylogenetic relationships rather than phenotypic characteristics, suggesting that VEE emergence has resulted from several distinct combinations of mutations that generate viruses with similar antigenic and equine virulence phenotypes.

[Study on the inclusion compound of phyllostachysin A and DMF]

The crystal structure of inclusion compound phyllostachysin A[1] and DMF, C20H26O6.C3H7ON, was determined by X-ray diffraction. A colorless block crystal with dimensions of 0.6 x 0.6 x 0.8 mm was used for analysis. It shows orthorhombic, and it's space group is P2(1)2(1)2(1) with a = 10.895(3), b = 13.237(2), c = 15.373(3) A, V = 2217.0(3) A3 Z = 4, Dc = 1.302 g cm-3. Direct method was applyed to determine the structure, and the parameters were refined by least square method. The final Rf factor is 0.060 and Rw = 0.083. The result shows that the crystal is formed by Phyllostachysin A and DMF by inclusion interaction.

Complete sequence and transposon mutagenesis of the BamHI J fragment of Cydia pomonella granulosis virus

The BamHI J fragment of Cydia pomonella granulosis virus was subcloned and subjected to transposon mutagenesis in Escherichia coli using a Tn3 derivative. After screening by restriction endonuclease digestion and polymerase chain reaction (PCR), 44 clones were selected representing insertions every 100 to 300 bp. The complete sequence was compiled and the transposon insertion sites mapped precisely by sequencing. Analysis of the sequence revealed the presence of 7 potential open reading frames (ORFs). The BamHI J fragment was already known to encode IAP and OPDV-E6. Three other ORFs encode products similar to known proteins, viz. an Autographa californica nuclear polyhedrosis virus 8.6 kDa protein, a Lymantria dispar nuclear polyhedrosis virus 34 kDa protein, and vertebrate reovirus omega-1 proteins. The ORF with similarity to omega-1 is also similar to baculovirus p10 proteins. In both cases, the similarity occurs in regions likely to form a coiled-coil structure.

Recombinational history and molecular evolution of western equine encephalomyelitis complex alphaviruses

Western equine encephalomyelitis (WEE) virus (Togaviridae: Alphavirus) was shown previously to have arisen by recombination between eastern equine encephalomyelitis (EEE)- and Sindbis-like viruses (C. S. Hahn, S. Lustig, E. G. Strauss, and J. H. Strauss, Proc. Natl. Acad. Sci. USA 85:5997-6001, 1988). We have now examined the recombinational history and evolution of all viruses belonging to the WEE antigenic complex, including the Buggy Creek, Fort Morgan, Highlands J, Sindbis, Babanki, Ockelbo, Kyzylagach, Whataroa, and Aura viruses, using nucleotide sequences derived from representative strains. Two regions of the genome were examined: sequences of 477 nucleotides from the C terminus of the E1 envelope glycoprotein gene which in WEE virus was derived from the Sindbis-like virus parent, and 517 nucleotide sequences at the C terminus of the nsP4 gene which in WEE virus was derived from the EEE-like virus parent. Trees based on the E1 region indicated that all members of the WEE virus complex comprise a monophyletic group. Most closely related to WEE viruses are other New World members of the complex: the Highlands J, Buggy Creek, and Fort Morgan viruses. More distantly related WEE complex viruses included the Old World Sindbis, Babanki, Ockelbo, Kyzylagach, and Whataroa viruses, as well as the New World Aura virus. Detailed analyses of 38 strains of WEE virus revealed at least 4 major lineages; two were represented by isolates from Argentina, one was from Brazil, and a fourth contained isolates from many locations in South and North America as well as Cuba. Trees based on the nsP4 gene indicated that all New World WEE complex viruses except Aura virus are recombinants derived from EEE- and Sindbis-like virus ancestors. In contrast, the Old World members of the WEE complex, as well as Aura virus, did not appear to have recombinant genomes. Using an evolutionary rate estimate (2.8 x 10(-4) substitutions per nucleotide per year) obtained from E1-3' sequences of WEE viruses, we estimated that the recombination event occurred in the New World 1,300 to 1,900 years ago. This suggests that the alphaviruses originated in the New World a few thousand years ago.

[The effect of anisodamine hydrochloride on globin chain synthesis in anemic mice]

We treated anemic mice with Anisodamine hydrochloride followed by Hb electrophoresis and detection of globin chain synthesis rate. We found that the synthesis of their globin chains remarkably increased and would last for approximately 10 days, While the results did not show any generation of fetal Hb, possible effect of the drug might come from the raising of alpha and beta globin chains of the adult mice.

Cloning and analysis of a cDNA encoding farnesyl diphosphate synthase from Artemisia annua

A cDNA encoding farnesyl diphosphate (FPP) synthase (FPPS) has been cloned from a cDNA library of Artemisia annua. The sequence analysis showed that the cDNA encoded a protein of 343 amino acid (aa) residues with a calculated molecular weight of 39420 kDa. The deduced aa sequence of the cDNA was highly similar to FPPS from other plants, yeast and mammals, and contained the two conserved domains found in polyprenyl synthases including FPPS, geranylgeranyl diphosphate synthases and hexaprenyl diphosphate synthases. The expression of the cDNA in Escherichia coli showed enzyme activity for FPPS in vitro.

Genetic conservation of Highlands J viruses

We studied molecular evolution of the mosquito-borne alphavirus Highlands J (HJ) virus by sequencing PCR products generated from 19 strains isolated between 1952 and 1994. Sequences of 1200 nucleotides including portions of the E1 gene and the 3' untranslated region revealed a relatively slow evolutionary rate estimated at 0.9-1.6 x 10(-4) substitutions per nucleotide per year. Phylogenetic trees indicated that all HJ viruses descended from a common ancestor and suggested the presence of one dominant lineage in North America. However, two or more minor lineages probably circulated simultaneously for periods of years to a few decades. Strains isolated from a horse suffering encephalitis, and implicated in a recent turkey outbreak, were not phylogenetically distinct from strains isolated in other locations during the same time periods. Our findings are remarkably similar to those we obtained previously for another North American alphavirus, eastern equine encephalomyelitis virus, with which Highlands J shares primary mosquito and avian hosts, geographical distribution, and ecology. These results support the hypotheses that the duration of the transmission season affects arboviral evolutionary rates and vertebrate host mobility influences genetic diversity.

Tests for possible effects of selection by domestic pyrethroids for resistance in culicine and anopheline mosquitoes in Sichuan and Hubei, China

Resistance tests, by conventional methods and by observing the time for knockdown, showed no evidence for any build up of resistance to deltamethrin in malaria vectors from areas where millions of bednets have been treated with this compound annually for up to 7 years. However, a strain of Culex quinquefasciatus which had been bred in a factory in which volatile pyrethroids are handled had developed unequivocal resistance to deltamethrin. Observation of the time for knockdown gave clearer discrimination between resistant and susceptible strains than did observation of percentage mortality after a standard exposure time.

Marked enhancement by rifampicin and lack of effect of isoniazid on the elimination of quinine in man

The effect of rifampicin and isoniazid pretreatment on the pharmacokinetics of quinine after a single oral dose (600 mg quinine sulphate) was studied in nine healthy young Thai male volunteers using a three-way randomized crossover design. Subjects were studied over three 2 day periods, during which they received no pretreatment, or pretreatment with daily 600 mg p.o. rifampicin for 2 weeks, or isoniazid 300 mg p.o. daily for 1 week, prior to quinine administration. The mean (+/- s.d.) clearance (CL/F) of quinine coadministered with rifampicin (0.87 +/- 0.35 1 h-1 kg-1) was significantly greater than that of quinine alone (0.14 +/- 0.05 1 h-1 kg-1). The mean difference in clearance from the control treatment was 0.73 1 h-1 kg-1, with 95% confidence interval (C.I.) of 0.48 to 0.98. The unbound clearance (CLu/F) of quinine, which reflects the activity of the drug-metabolizing enzymes, was considerably greater (6.9-fold) in subjects when rifampicin was coadministered with quinine than that of quinine alone (6.9 +/- 3.6 vs 1.0 +/- 0.5 1 h-1 kg-1; the 95% C.I. for the mean difference was 3.3 to 8.5). The mean elimination half-life of quinine when coadministered with rifampicin (5.5 +/- 3.0 h) was significantly shorter than when quinine was given alone (11.1 +/- 3.0 h; the 95% C.I. for the mean difference was -8.6 to -2.6). In contrast to rifampicin, pretreatment for 1 week with 300 mg oral isoniazid had no significant effects on the pharmacokinetics of quinine.(ABSTRACT TRUNCATED AT 250 WORDS)

Radioautographic study of the macromolecular synthesis of Leydig cells in aging mice testis

The studies on DNA, RNA and protein synthesis of Leydig cells in aging mice testis of several groups were carried out by light microscopic radioautography. The cells labelled with 3H-thymidine, 3H-uridine and 3H-leucine were observed in various aging groups. The labeling index with 3H-thymidine was low at embryonic and early postnatal stages. It increased slightly at 6 months, reached its peak at 9 months and maintained a relatively high level at a later period. The number of the silver grains labelled with 3H-uridine over the nuclei and cytoplasm were observed from embryonic day 19 and increased from 3 months onwards. From adult to old ages, the activity of 3H-uridine incorporation was maintained at a high level in the nuclei and a relatively low level in the cytoplasm. The aging change of 3H-leucine incorporation was found from this experiment. The labeling indices between embryonic and early postnatal stages showed no obvious differences while the number of the silver grains over both cytoplasm and nucleus increased from 6 months onwards and was maintained a high level until old age.

Large-scale spraying of bednets to control mosquito vectors and malaria in Sichuan, China

Since 1987, up to 2.42 million bednets owned by rural householders in over 40 counties in seven prefectures of Sichuan Province, China, have been sprayed annually with deltamethrin at a dose of about 10 mg/m2. Data for the years 1987-89 indicate that there were marked reductions in the biting populations and survival of the two vector species Anopheles anthropophagus and A. sinensis. Extensive tests in 1992 in areas where bednet spraying had been carried out for 5 years showed that mortality was 100% with the WHO-recommended discriminating dose of deltamethrin, i.e., there was no indication of resistance. Malaria data obtained by passive surveillance of reported cases, mass blood surveys of schoolchildren, and active surveillance of reported blood slides from fever cases all indicated marked reductions after introduction of the net spraying. In contrast, in the control areas, where the nets were not treated, the situation remained static or deteriorated slightly.

Structural organization of the mouse DNA repair gene, N-methylpurine-DNA glycosylase

N-Methylpurine-DNA glycosylase (MPG), a ubiquitous DNA repair enzyme, removes N-alkylpurines and other purine lesions induced in DNA by simple alkylating carcinogens. A mouse MPG cDNA clone was isolated from a lambda recombinant phage library of BALB/c mouse lung cell and characterized. Using the mouse MPG cDNA as a probe, the complete mouse MPG gene was isolated in two overlapping lambda recombinant genomic clones. The 6-kb gene has four exons containing 1,002 bp of coding sequence. The transcription start site was identified in the genomic sequence by primer extension of MPG mRNA from a mouse lung fibroblast cell line. The location of this transcription start site was confirmed by in vitro transcription with the promoter-containing plasmid template. Promoter function of the sequence 5' upstream of the transcription initiation site was shown by transient expression of the firefly luciferase reporter gene under the control of this sequence in transfected human and mouse cells. The mouse MPG promoter contains no TATA box, but has a CAAT element and is G.C-rich with putative AP2 elements and SP1-complementary sequences.

A simultaneous study of Doppler-echo and catheterization in noninvasive assessment of the left ventricular dp/dt

To confirm the feasibility and accuracy of the method for the noninvasive measurement of the left ventricular dp/dt, 53 patients with mitral regurgitation underwent simultaneous determination of left ventricular dp/dt by continuous-wave Doppler echocardiography and cardiac catheterization. Doppler-determined left ventricular dp/dt is derived from the Doppler mitral regurgitant spectrum by dividing the magnitude of the left ventricular-atrial pressure gradient rise between 1 and 3 m/s of the mitral regurgitant velocity signal by the time taken for this change. Left ventricular dp/dt by Doppler ranged from 629 to 3494 mmHg/s (mean +/- SD, 1971 +/- 785 mmHg/s), and that by catheterization varied between 716 and 3650 mmHg/s (mean +/- SD, 1974 +/- 727 mmHg/s). There was a high correlation (r = 0.93, y = 0.862x + 274.77, SEE = 271 mmHg/s, p < 0.001) of left ventricular dp/dt between the two techniques. It is concluded that left ventricular dp/dt is one of the most commonly used parameters for the evaluation of left ventricular systolic function and that Doppler echocardiography provides a new, accurate and noninvasive method of evaluation.

A cell culture model system for genetic analyses of the cell cycle by targeted homologous recombination

Analysis of how external proliferation signals impinge on the regulation of the cell cycle is ideally performed in cells that are capable of normal physiological withdrawal into the quiescent (G0) phase of the cell cycle as well as resumption of growth following appropriate stimuli. Targeted homologous recombination (gene targeting) provides an important new approach to determine the function of specific genes in these cellular processes. Current gene targeting methodology necessitates the use of immortal and stably diploid cell lines. This report investigates several rodent cell lines, by both genetic and physiological criteria, for use in gene targeting studies of the G0 to G1 transition. All murine cell lines examined were aneuploid. Some rat cell lines were euploid by chromosome number, but three specific genes, c-myc, c-raf-1 and Rb, were not always diploid. Only one cell line, an early-passage subclone of the Rat-1 cell line, was diploid for c-myc, c-raf-1 and Rb. An hprt- derivative of this cell line was isolated (designated TGR-1) and its karyotype was established by G-banding. TGR-1 cells were shown to withdraw into G0 upon serum starvation and to uniformly enter S phase after refeeding. Expression patterns of the c-myc, c-raf-1 and Rb genes and several properties of the gene products were found to be normal. The frequency of targeted homologous recombination of the c-myc and c-raf-1 loci was found to be within values observed with other cell lines. Thus, by both genetic and physiological criteria the TGR-1 cell line is a good model system for the analysis of the roles of c-myc, c-raf-1 and Rb in signal transduction, and will probably prove useful in studies involving other genes.

Noninvasive evaluation of right ventricular and pulmonary artery systolic pressures in patients with ventricular septal defects: simultaneous study of Doppler and catheterization data

The method for evaluating right ventricular and pulmonary artery systolic pressures by subtracting the systolic pressure gradient across the ventricular septal defect from the cuff systolic blood pressure is documented. To confirm the reliability and accuracy of this method, simultaneous continuous wave Doppler echocardiography and left and right cardiac catheterization were performed in 66 patients with congenital ventricular septal defects. The comparisons between the Doppler-derived right ventricular or pulmonary artery systolic pressures and those measured by catheterization yielded an excellent correlation (r = 0.969, y = 1.035x - 3.627, SEE = 8.2 mm Hg, p < 0.001 and r = 0.972, y = 1.012x - 2.904, SEE = 7.6 mm Hg, p < 0.001), respectively. There was a close agreement between the Doppler-derived right ventricular or pulmonary artery systolic pressures and those measured by catheters, and the differences between the two measurements did not differ significantly from zero. It is concluded that Doppler echocardiography offers a reliable and accurate method for noninvasive assessment of right ventricular and pulmonary artery systolic pressures in patients with ventricular septal defects.

Noninvasive evaluation of interventricular pressure gradient across ventricular septal defect: a simultaneous study of Doppler echocardiography and cardiac catheterization

Simultaneous continuous-wave Doppler echocardiography and left- and right-sided cardiac pressure measurements were performed during cardiac catheterization in 64 patients with a congenital ventricular septal defect (VSD). The peak-to-peak pressure gradient across the VSD on cardiac catheterization ranged from 0 to 109 mm Hg (61 +/- 31.7 mm Hg). The peak shunt velocity and peak pressure gradient across the VSD on Doppler ultrasound imaging ranged from 0.96 to 5.21 m/sec (3.75 +/- 1.16 m/sec) and from 4 to 105 mm Hg (62 +/- 29.8 mm Hg), respectively. Doppler measurements of the peak interventricular pressure gradient correlated well with measurements obtained by cardiac catheterization (r = 0.98, standard error of estimate = 6.3 mm Hg, p less than 0.001). Doppler ultrasound imaging yielded information comparable to that obtained by catheterization and provided an accurate method of measuring the pressure gradient across the VSD, which is a useful parameter for the assessment of pulmonary artery systolic pressure in patients with a VSD, without a left or right ventricular outflow tract obstruction.

[Validation of Doppler-derived interventricular pressure gradients in patients with ventricular septal defect comparing with catheterization study]

To evaluate the accuracy of Doppler echocardiography for measuring the interventricular pressure gradient in patients with ventricular septal defect (VSD), Doppler echocardiography and dual catheters were performed simultaneously in 31 cases with VSD ranging from 9 to 40 years old. The systolic jet velocities through VSD were recorded by the continuous-wave Doppler technique and converted to the peak instantaneous pressure gradient (delta Pp) and the mean pressure gradient (delta Pm) using a modified Bernoulli's equation with the aid of computer system. Both left and right heart catheters were performed to record the left (LVSP) and the right (RVSP) ventricular systolic pressure simultaneously. Guided by the color flow image Doppler technique, the tip of the right heart catheter was carefully placed within the jet area of the right ventricle. The following parameters were measured from the ventricular pressure curves, the peak instantaneous pressure gradient (IPG), the peak to peak pressure gradient (PPG) and the mean pressure gradient (MPG). The comparison between delta Pp and PPG yielded an excellent correlation (r = 0.99, SEE = 0.69 kPa). There was a close agreement between delta Pp and IPG (r = 0.99, SEE = 0.64 kPa). However, the correlation between delta Pm and MPG was also high (r = 0.98, SEE = 0.67 kPa). We conclude that Doppler echocardiography offers a reliable technique for measuring the interventricular pressure gradient in patients with VSD.

Cloning and analysis of the nuclear gene for YmL33, a protein of the large subunit of the mitochondrial ribosome in Saccharomyces cerevisiae

The N-terminal amino acid sequence of a large subunit protein, termed YmL33, of the mitochondrial ribosome of the yeast Saccharomyces cerevisiae was determined. The data were obtained to synthesize two kinds of oligonucleotide primers, which were used in the polymerase chain reaction to amplify and clone the nuclear gene for this protein. By nucleotide sequencing, the cloned gene, MRP-L33, was found to encode a basic protein of 11 kDa with 98 amino acid residues. The protein encoded by this gene appears to have no leader sequence at its N terminus. The N-terminal two-thirds of the deduced amino acid sequence showed a significant degree of sequence similarity to ribosomal protein L30 of Escherichia coli and Bacillus stearothermophilus. In addition, the C-terminal one-third showed sequence similarity, though to a lesser extent, to a yeast cytoplasmic ribosomal protein termed L16. By hybridization with the yeast chromosomes and their restriction enzyme fragments, the MRP-L33 gene was concluded to exist on chromosome XIII as a single-copy gene. Disruption of the gene by insertion of a HIS3-containing fragment showed that MRP-L33 was essential for mitochondrial function. The transcriptional level of MRP-L33 in strains with different mitochondrial genetic backgrounds was analyzed in the presence of glucose, galactose, or glycerol.