Acupuncture at otoacupoint heart for treatment of vascular hypertension

The immediate, short-term and long-term depressor effects, the immediate effects on cardiac functions in grade II and grade III vascular hypertension, and the effects on angiotensin II in grade III vascular hypertension by acupuncture at otoacupoint Heart were studied in 30 cases of vascular hypertensive patients. The immediate depressor effect of acupuncture at otoacupoint Stomach was also recorded for comparison. It was found that acupuncture at otoacupoint Heart produced marked immediate depressor effect, and the short-term effective rate was 100%, the long-term effective rate was 63.3%, as well as evident immediate effects on cardiac functional activities in grade II and grade III hypertension and marked effects on angiotensin II in grade III hypertension. Acupuncture at otoacupoint Stomach produced no depressor effect on vascular hypertension.

Experimental investigation of Bessel beam characteristics

We report on an experimental characterization of Bessel beams with finite apertures. We show that real Bessel beams can be generated with intensity profiles that closely resemble the ideal J(0)(2) transverseintensity distribution of Bessel beams. We also show interferometrically that these beams have planar phase fronts with pi-phase shifts from one Bessel ring to the next. We report tolerance conditions for Bessel beam generation and give an example of this generation that uses an unstable resonator as the light source.

The efficient intracellular sequestration of the insulin-regulatable glucose transporter (GLUT-4) is conferred by the NH2 terminus

GLUT-4 is the major facilitative glucose transporter isoform in tissues that exhibit insulin-stimulated glucose transport. Insulin regulates glucose transport by the rapid translocation of GLUT-4 from an intracellular compartment to the plasma membrane. A critical feature of this process is the efficient exclusion of GLUT-4 from the plasma membrane in the absence of insulin. To identify the amino acid domains of GLUT-4 which confer intracellular sequestration, we analyzed the subcellular distribution of chimeric glucose transporters comprised of GLUT-4 and a homologous isoform, GLUT-1, which is found predominantly at the cell surface. These chimeric transporters were transiently expressed in CHO cells using a double subgenomic recombinant Sindbis virus vector. We have found that wild-type GLUT-4 is targeted to an intracellular compartment in CHO cells which is morphologically similar to that observed in adipocytes and muscle cells. Sindbis virus-produced GLUT-1 was predominantly expressed at the cell surface. Substitution of the GLUT-4 amino-terminal region with that of GLUT-1 abolished the efficient intracellular sequestration of GLUT-4. Conversely, substitution of the NH2 terminus of GLUT-1 with that of GLUT-4 resulted in marked intracellular sequestration of GLUT-1. These data indicate that the NH2-terminus of GLUT-4 is both necessary and sufficient for intracellular sequestration.

A comparative study of the efficacy and morbidity of five techniques for ridge augmentation of the mandible

Severely atrophic mandibles were augmented in 254 patients using five different surgical procedures, followed by total lowering of the floor of the mouth, vestibuloplasty, and skin graft. Patients were evaluated on a long-term basis to compare efficacy of treatment subjectively by recording patient complaints and by objectively assessing ridge form clinically and radiographically. Patients, in general, were pleased with the short- and long-term results of all five procedures. The ideal ridge form, comma-shaped, was obtained at a much higher rate with the three procedures using hydroxylapatite (HA) alone or in combination with collagen (HA-PFC). Ridge height loss both anteriorly and posteriorly was more severe in the two visor groups with bone graft or with HA than in those with only the alloplast. Labial sensory alterations more frequently occurred in the visor bone graft group, and wound dehiscence and lack of skin graft take were seen most often in the HA-PFC groups. Despite great differences in the quality of ridges obtained and in the number of complications between the visor groups and the alloplast groups, general patient satisfaction with any of the five procedures could be explained by the severity of the original complaints and because muscle interference has been eliminated in all cases by lowering of the floor of the mouth.

Stabilities and properties of multilinked hemoglobins

Crosslinking of both human and dog hemoglobin has been done with a variety of reagents to produce singly, doubly and multiply crosslinked hemoglobins. Succinate and glutarate diaspirins did not crosslink deoxy human hemoglobin in good yield, in contrast to the fumarate analog (DBSF). Deoxy dog Hb did not react well with DBSF, but oxy dog Hb did react, giving crosslinked tetramers as well as dimers on SDS electrophoresis. Crosslinking with a short, rigid reagent (difluorodinitrobenzene) resulted in a similar product for both oxy and deoxy hemoglobin that had high stability and oxygen affinity. The trilinker, tris-chloroethylamine, produced a more stable product than the corresponding crosslinker, bis-chloroethylamine. Double crosslinking oxy Hb with DBSF and dimethylpimelimidate or with DBSF followed by deoxygenation and recrosslinking with DBSF gave products with higher denaturation temperatures. The diaspirin double crosslinked product had high oxygen affinity.

Synthesis and biodistribution of the alpha 2-adrenergic receptor antagonist (11C)WY26703. Use as a radioligand for positron emission tomography

The purpose of these experiments was to label an alpha 2-adrenergic receptor ligand with a positron emitting isotope and then test this radioligand in vivo. No-carrier-added [11C]WY26703 was synthesized by methylation of its desmethyl precursor, WY27050 with [11C]H3I followed by purification with HPLC in 14% yield in a synthesis time of 35 min from EOB. Ki values for unlabeled WY26703, ranged from 0.52-1.55 nM in tissues that express a single alpha 2-adrenergic receptor subtype. Tail vein injections of [11C]WY26703 in mice revealed that the compound was distributed in the brain, heart, lungs, spleen, and kidneys. In the brains of rats treated with atipamezole, an alpha 2-adrenergic receptor antagonist, there was no decrease in [11C] accumulation indicating a lack of observable specific binding of the radioligand. When brain tissue was homogenized and filtered, however, atipamezole decreased [11C] activity by 53%. Therefore, [11C]WY26703 crosses the blood-brain barrier and specifically binds to alpha 2-adrenergic receptors with high affinity. Atipamezole treatment decreased only the area of the locus coeruleus [11C] value of the various regions of the brain. The affinity, however, of [11C]WY26703 does not appear to distinguish alpha 2-receptors from nonspecific binding sites. PET study of [11C]WY26703 in a Rhesus monkey showed that influx of [11C]WY26703 into the brain was high for the first few minutes but radioactivity then declined rapidly and did not retain in a specific brain region. This suggests that [11C]WY26703 may not be a useful ligand for imaging human alpha 2-adrenergic receptors by positron emission tomography.

The transition from late G1 to early S phase is most vulnerable to the coclastogenic effect of ultraviolet radiation plus arsenite

It has previously been reported that chromosome aberrations induced by ultraviolet (UV) radiation can be enhanced by treatment with sodium arsenite for 24 h post-irradiation. Using synchronized CHO-K1 cells, it has now been established that cells in the transitional stage from late G1 to early S phase are most vulnerable to the coclastogenic effect of treatment with UV radiation and arsenite. This result cannot be explained by the special vulnerability of cells in the late G1 to early S transition to UV clastogenicity, as the coclastogenic effects of UV and caffeine or UV and arabinofuranosylcytosine were detected when treating the mid-S but not late-G1 or G2 phase cells.

Unstable tibio-fibular fractures treated with an external fixator--a clinical report of 1033 cases

From 1977 to 1987, 1033 cases of unstable tibio-fibular fractures were treated with an external fixator designed by the authors. Among them, 232 involved open fractures. All of the patients were followed up for 4 to 90 months (average 20 months). The duration of bed confinement averaged 8.3 days, and the mean time necessary for clinical bone union was 54 days. Anatomical or nearly anatomical bone apposition was effected in 878 cases (85.0%), functional apposition in 141 cases (13.6%) and malunion in 14 cases (1.4%). The overall functional results were as follows: excellent in 769 cases (74.4%), good in 218 cases (21.1%), fair in 32 cases (3.1%), and poor in 14 cases (1.4%). The design of the device and its indications are also discussed.

Chronic nonocclusive coronary artery constriction in rats. Beta-adrenoceptor signal transduction and ventricular failure

To determine the effects of chronic coronary artery constriction on the relationship between cardiac function and regulation of beta-adrenoceptor signal transduction, the left main coronary artery was narrowed in rats and the animals were killed 5 mo later. An average reduction in coronary luminal diameter of 44% was obtained and this change resulted in an increase in left ventricular end-diastolic pressure and a decrease in positive and negative dP/dt. Significant increases in left and right ventricular weights indicative of global cardiac hypertrophy were observed. Radioligand binding studies of beta-adrenoreceptors, agonist-stimulated adenylate cyclase activity, and ADP ribosylation of 45-kD substrate by cholera toxin were all depressed in the failing left ventricle. In contrast, in the hypertrophic non-failing right ventricle, beta-adrenoreceptor density was preserved and receptor antagonist affinity was increased. In spite of these findings at the receptor level, agonist stimulated cyclic AMP generation was reduced in the right ventricular myocardium. The quantity of the 45-kD substrate was also decreased. In conclusion, longterm nonocclusive coronary artery stenosis of moderate degree has profound detrimental effects on the contractile performance of the heart in association with marked attenuation of adrenergic support mechanisms.

Isolation and sequence analysis of TGA1 cDNAs encoding a tomato G protein alpha subunit

We have isolated cDNAs for a gene coding for a G protein alpha subunit from tomato (Lycopersicon esculentum, cv. VF36). This gene, named TGA1, was isolated using a cDNA of the Arabidopsis thaliana G protein alpha subunit-encoding gene, GPA1, as a DNA probe. The sequences of four cDNA clones indicate that the deduced amino acid (aa) sequence of the gene product (TG alpha 1) has 384 aa (44906 Da). The predicted TG alpha 1 protein exhibits similarity to all known G protein alpha subunits. The aa are 84.6% identical and 93% similar (identical and conservative changes) to A. thaliana GP alpha 1, and 34% identical and 59% similar to mammalian transducins. Furthermore, it has all of the consensus regions for a GTP-binding protein. Finally, hybridizations of tomato genomic DNA indicate that TGA1 is a single-copy gene.

Maternal, paternal, additive, and dominance components of variance in Gerbera

Estimates of additive, dominance, maternal, and paternal components of variance were obtained for a sample of 18 traits, including measurements of yield, scapes, flowers, disk, ray and trans florets, leaves, and branching in the Davis population of Gerbera hybrida. The results, based on the covariance of reciprocals, indicate that although heritability averaged 0.52, extranuclear maternal or paternal effects are not important sources of variability. Therefore, reciprocal differences do not seriously affect estimates of additive variance or heritability in this population.

Characterization of monoclonal antibodies against the human immunodeficiency virus matrix protein, p17gag: identification of epitopes exposed at the surfaces of infected cells

Eight monoclonal antibodies reactive with the matrix protein of human immunodeficiency virus type 1 (HIV-1), p17gag, were isolated from rats which had been immunized with solubilized HIV-1 lysate. The epitope specificities of these antibodies were determined with a series of synthetic peptides representing overlapping regions of p17. Six of the antibodies were mapped to three distinct regions of p17, while two antibodies (G11g1 and G11h3) reacted only with intact recombinant p17, suggesting that they were directed against conformational or discontinuous epitopes. All the antibodies bound to HIV-infected cells which had been permeabilized with acetone, but only G11g1 and G11h3 reacted with live HIV-infected cells. Specificity studies with diverse virus strains demonstrated that these two antibodies recognized distinct epitopes, one which was group specific for HIV-1, and one which was shared with HIV type 2 and simian immunodeficiency virus. Binding competition studies indicated that these epitopes were proximal in native p17. Despite their reactivity with intact cells, these two antibodies did not possess appreciable virus-neutralizing activity. These results indicate that a form of p17 is expressed on the surfaces of live HIV-infected cells which is accessible to some, but not all, antibodies against p17. These cell surface molecules may play a role in the generation of antibodies against p17gag that are characteristic of early stages of HIV infection, and they may act as natural targets for the immune system and as potential targets for immunotherapy of HIV-infected cells.

Cyclic matrix representation for sequential multiplication of complex matrices

A cyclic matrix representation for complex numbers is proposed for sequential multiplication of complex matrices. The related optical implementation is discussed.

Overlapping retrovirus U5 sequence elements are required for efficient integration and initiation of reverse transcription

A secondary structure in the 5' noncoding region of avian retrovirus RNA, called the U5-leader stem, was shown previously to have a role in initiation of reverse transcription (D. Cobrinik, L. Soskey, and J. Leis, J. Virol. 62:3622-3630, 1988). We now show that an additional RNA secondary structure near the U5 terminus, called the U5-IR stem, is also important for reverse transcription. Mutations that disrupt the U5-IR stem cause a replication defect associated with both a decrease in synthesis of viral DNA in infected cells and a decrease in initiation of reverse transcription in melittin-permeabilized virions. Structure-compensating base substitutions in the U5-IR restore reverse transcription efficiency. In viral DNA, U5-IR sequences are included in the U5 terminal region that functions as a viral integration donor site. When base substitutions are introduced into these sequences, a reduced efficiency of integration in vitro and in vivo is observed. These observations indicate that U5-IR sequences have a structural role in reverse transcription of viral RNA and a sequence-specific role in the integration of viral DNA.

Noncoordinate regulation of alpha-1 adrenoreceptor coupling and reexpression of alpha skeletal actin in myocardial infarction-induced left ventricular failure in rats

To determine the effects of myocardial infarction-induced left ventricular failure on the regulation of surface alpha-1 adrenoreceptors and signal transduction, large infarcts were produced in rats and the animals killed seven days later. After the documentation of impaired left ventricular pump performance, radioligand binding studies of the alpha-1 adrenoreceptor, norepinephrine-stimulated phosphoinositol turnover, and ADP ribosylation of 41 kD substrate by pertussis toxin were examined in the hypertrophying unaffected myocardium. Moreover, the expression of sarcomeric actin isoforms was analyzed by Northern blots and hybridization with specific oligonucleotide probes. Alpha-1 adrenoreceptor density was found not to be altered in membranes obtained from the spared left ventricular tissue, whereas phosphoinositol turnover was increased 3.1-fold in the viable myocytes of infarcted hearts. Furthermore, pertussis toxin substrate was augmented 2.5-fold in membranes prepared from the surviving left ventricular myocardium. Finally, an upregulation of the skeletal actin isoform was detected in the tissue of the failing left ventricle. In conclusion, the possibility is raised that in the presence of severe myocardial dysfunction and ongoing reactive hypertrophy, effector pathways linked to the alpha-1 adrenoreceptor may stimulate the myocyte hypertrophic response which would tend to normalize cardiac hemodynamics. The reexpression of alpha skeletal actin may be a molecular indicator of the persistance of an overload on the myocardium.

Parallel multiple matrix multiplication using an orthogonal shadow-casting and imaging system

A novel orthogonal shadow-casting and imaging optical system is proposed for performing multiple matrix multiplication. An analysis is given for describing the construction of a matrix processor. Preliminary experiments of matrix multiplication are demonstrated.

Quantitative analysis of correlations among flower traits in Gerbera hybrida Compositae : 1. Genetic and environmental correlations

Phenotypic (r p ), genetic (r g ), and environmental, (r e ) correlations were estimated for 38 flower traits in the Davis population of gerbera (Gerbera hybrida, Compositae). Fifty-two percent of r p and 38% of r g were statistically significant at P < 0.05. Significant negative r p were infrequent, but significant negative r g occurred in 10% of cases. There was a negative correlation between estimates of r g and r e , resulting in cases where r g was significant, but r p was not. Individual traits varied in their tendency to correlate phenotypically or genetically, and positively or negatively, with other traits. Traits within the same morphological category, such as disk florets or transitional florets, were more highly intercorrelated than were traits from different categories.

Quantitative analysis of correlations among flower traits in Gerbera hybrida, Compositae : 2. Direct and mean correlated response to selection

A Mean Correlation Response (MCR) model was developed to estimate the relative effectiveness of direct selection when other traits also respond to the selection. A measure of the relative effects of mean correlated response and direct response (R) and a measure of the relative efficiency of direct selection (IE) were applied to a genetic correlation matrix of 38 traits. These were measurements of inflorescence, receptacle and involucre, scape, disk florets, ray florets, and trans florets in the Davis population of Gerbera hybrida, Compositae. Generally, traits with high heritability had high direct and mean correlated response; these were often traits measuring disk and trans florets. Traits with low heritability had low direct and mean correlated response; these were often traits measuring the inflorescence. Traits of the inflorescence had the lowest efficiency of direct to mean correlated response.

[Immunisation of spontaneously hypertensive rats against angiotensin I]

Immunization against angiotensin I has been considered in comparison with the immunization against renin, in the spontaneously hypertensive rat (SHR). Among 6 different methods of immunization, two (AI-gluta-LPH and AI-Carbo-LPH coupling) permitted to obtain high levels of antibodies against angiotensin I (higher than 1/10,000), after four injections of 50 micrograms AI at three weeks interval. The titration of the antibodies was realized in radio-immuno-assay (RIA), with the determination of the cross-reactivity with AII by the same method. Characterization of the isotypes and the affinity calculation were realized with the ELISA method. The average level of antibodies is about 1/10,000 to 1/100,000, and the cross reactivity of the antibodies for AII is about 0.1 p. 100 in RIA. In ELISA, the study of the different isotypes shows a good maturation of the immune system with a sharp elevation of the IgG1 and IgG2 alpha isotypes, after 2 or 3 injections. The affinity of the antibodies purified by affinity chromatography is about 10.3 10(-9) M. The weekly measure of the arterial pressure during 6 months does not reveal at any moment a fall of pressure during the immunizations. The average pressure of the immunized group (209.4 +/- 23.8 mmHg, n = 40) is non significantly different from the average pressure of the mock group (208.5 +/- 22.6 mmHg, n = 10).

Elevation of glutathione levels and glutathione S-transferase activity in arsenic-resistant Chinese hamster ovary cells

Arsenic-resistant Chinese hamster ovary (CHO) cells were established by progressively increasing the concentration of sodium arsenite in culture medium. One of the resistant clones, SA7, was also cross-resistant to As(V), Zn, Fe(II), Co, and Hg. The susceptibilities to sodium arsenite in parental CHO cells, revertant SA7N cells, and resistant SA7 cells were correlated with their intracellular glutathione (GSH) levels and glutathione S-transferase (GST) activity. The resistance in SA7 cells was diminished by depletion of GSH in cells after treatment with buthionine sulfoximine. Furthermore, after reexposure of revertant SA7N cells to sodium arsenite, the intracellular GSH levels, GST activity, and resistance to sodium arsenite were raised to the same levels as SA7 cells. These data indicate that the elevation of intracellular GSH levels and GST activity in SA7 cells may be responsible for the resistance to arsenite. A p25 protein, which could be a monomer subunit of GST, accumulated in SA7 cells. In addition, an outward transport inhibitor, verapamil, indiscriminately increased the arsenite toxicity in resistant and parental cells.

Immunochemical quantitation of thymine glycol in oxidized and X-irradiated DNA

The present study demonstrates the usefulness of immunochemical assays for quantitating modified bases in oxidized and X-irradiated DNA. Escherichia coli, phi X174 RF I, PM2, and M13 DNA containing thymine glycols introduced by OsO4 oxidation were used as antigens in a direct enzyme-linked immunosorbent assay (ELISA). The number of thymine glycols per DNA molecule was determined by reactivity with antithymine glycol antibody standardized either to the acetol fragment assay or to the number of Escherichia coli endonuclease III-sensitive sites. The number of thymine glycols was also determined in phi X174 RF I DNA X-irradiated in either phosphate or Tris buffer under air. Using a direct ELISA with phi X174 RF I DNA irradiated in a phosphate buffer solution, the anti-thymine glycol antibody detected damage at the level of 40 Gy. The immunochemical assay was sensitive, specific, quantitative, and independent of DNA structure.

Trial of deltamethrin impregnated bed nets for the control of malaria transmitted by Anopheles sinensis and Anopheles anthropophagus

In 1985-1987, a field trial of malaria control using deltamethrin impregnated mosquito nets was carried out with 4,450 people in the Buji district, Bao'an County, Guangdong Province, China. The vectors were exophilic Anopheles sinensis (80%) and the endophilic and anthropophilic An. anthropophagus (20%). The first impregnation of the nets was in June 1985 and the second in April 1986. About 87% of the population slept under treated nets. The indoor vector density decreased by 93% and remained at the same level during the second year. During the second year the average monthly malaria incidence was 1.3% for January-June, a decrease of 74.6% as compared with pretreatment data, and 0.85% from July to December, a decrease of 92.7%. In April 1986 and April 1987, the treatment was extended to the whole Buji District, which has a total population of approximately 40,000. The average monthly malaria incidence (April-December 1986 and 1987) was 0.54% and 0.17%, a decrease of 64.7% and 89% respectively as compared with the same period for the previous year.

Measurement of angiotensin II concentration in rat plasma: pathophysiological applications

A very reliable isocratic reverse phase high performance liquid chromatography (HPLC) system has been developed to separate angiotensins, which combined with a very sensitive radioimmunoassay, provided precise measurements of the endogenous angiotensin II (AII) concentration in the rat plasma in different experimental circumstances. The overall recoveries of AII were 95.2 +/- 15.8% (means +/- SD) when 10 pg of this peptide was added to 1 ml of human plasma. The coefficient of variation for within-assay precision was 10% (n = 6). The plasma AII, measured by this method, of normal male pentobarbital-anesthetized rats was 53.0-141.6 pg/ml (mean: 103.9 +/- 29.7 pg/ml). The plasma AII of rats fed a sodium deficient diet was 300.0 +/- 100.6 pg/ml, while that of rats given oral Enalapril, an angiotensin converting enzyme (ACE) inhibitor, for 1 week was 35.7 +/- 28.0 pg/ml. The plasma AII of bilaterally nephrectomized rats was 2.7 +/- 2.9 pg/ml 24 hours after nephrectomy and below the detection limit 48 hr after nephrectomy. This method, therefore, can be used to study AII in different pathophysiological states or after treatment with renin-angiotensin system inhibitors.

Is the rate of disappearance of echo contrast from the interventricular septum a measure of left anterior descending coronary artery stenosis?

Although myocardial contrast echo has been used recently in human studies, no study is available at the present time which relates contrast echo findings to the degree of coronary artery stenosis. The present study is the first attempt to determine whether a quantitative relationship exists between regional myocardial echo contrast disappearance rate ('washout') and the severity of coronary artery stenosis. Manual injection of sonicated iopamidol (Iopamiro 370) into the left main coronary artery with simultaneous cross-sectional echo registration provided the myocardial echo-contrast images. From the digitized images, an echo contrast time-intensity curve was constructed for the proximal basal interventricular septum (region I) and the mid-distal portion of the interventricular septum (region II). From these curves, T50 was calculated after Fourier transformation and mono-exponential curve fitting. The percentage stenosis area (%A) of the left descending coronary artery (LAD) was calculated from routine coronary arteriograms using a computer-based system. Thirty patients (22 men, 8 women; mean age 58 +/- 10 years) were included in the study. Group I (n = 7) had normal LAD, group II (n = 18) had LAD stenosis of varying degrees. Five patients were not suitable for quantitative evaluation. A curvilinear relation was found between T50 and %A. (T50 = 3.0 x e0.01%A; r = 0.78; P less than 0.05). Patients with asynergy had significantly longer T50 (8.2 +/- 2.5 s) than did patients without asynergy (4.2 +/- 1.5 s) (P less than 0.05). All patients with greater than 75% LAD %A had prolonged T50. T50 might be useful index for studying regional myocardial perfusion during cardiac catheterization.

Does echocardiography allow the monitoring of the cardiac effects of nitrates?

Echocardiography is a very useful non-invasive method of cardiac diagnosis. It has been widely used in evaluating the effects of some drugs, such as nitrates, prazosin, and propranolol, on heart and seems very successful. In this paper, the echocardiographic studies of the effects of nitrates on left ventricular dimension and volume have been reviewed and an attempt has been made to answer whether or not echocardiography can allow to monitor the effects of nitrates in patient groups and further in individual patients.

Development of articulation before delayed hard-palate closure in children with cleft palate: a cross-sectional study

The development of articulation before surgical closure of the hard palate was compared in 75 preschool children with cleft lip and palate and 40 preschool children born without clefts. The children were aged 2 years to 5 years 11 months. The patients had significantly poorer articulation skills than the controls at each age level. Substitutions were the most frequent error, and they did not decrease with age in the patients. Fistula size and a history of speech therapy were significant factors in the articulation error scores only in 5-year-olds. No advantage in articulation proficiency was found for those who had worn a prosthesis to occlude the hard-palate defect.

Engineered defective interfering RNAs of Sindbis virus express bacterial chloramphenicol acetyltransferase in avian cells

We are investigating the feasibility of using the positive-strand RNA virus Sindbis virus and its defective interfering (DI) particles as vectors for introducing foreign genes into cells. In previous work we showed by deletion mapping of a cloned cDNA derived from one of the DI RNAs that only nucleotides at the 3' and 5' termini of the RNA are essential for the DI RNA to be amplified after it is transfected into cells in the presence of helper virus. As a first step in developing a vector we replaced 75% of the internal nucleotides of this DI cDNA with foreign sequences including the bacterial chloramphenicol acetyltransferase (CAT; EC 2.3.1.28) gene. DI RNAs transcribed from this cDNA were replicated and packaged by helper Sindbis virus and became a major viral RNA species in infected cells by the third passage after transfection. They were also translated to produce enzymatically active CAT. CAT activity was measured at passage 3 but could also be detected in transfected cells. DI RNAs containing the CAT gene were translated in vivo and in vitro to produce two polypeptides immunoprecipitable by anti-CAT antibodies. One polypeptide was identical in size to the authentic CAT polypeptide; the other was the size expected for a protein initiated at an upstream, viral-specific AUG in frame with the CAT AUG. These studies establish that DI genomes of Sindbis virus can tolerate the insertion and direct the expression of at least one foreign gene.

Identification and isolation of mycoplasmas by immunobinding

This laboratory has developed an immunobinding assay (IBA) to identify and detect mycoplasmas in a variety of specimens. The specimen is inoculated in volumes of 10 microliters onto nitrocellulose (NC) paper, which is then blocked, fixed, and incubated at room temperature. Specific antimycoplasma polyclonal or monoclonal antibody is first added, followed by peroxidase-labeled antibody directed toward the first immunoglobulin. Alternately, antimycoplasma IgG can be purified and conjugated to horseradish peroxidase for use in a direct assay. Addition of a developing solution results in the formation of purple color when mycoplasmas are present. Titers of rabbit antimycoplasma antisera range from 1:1,000 to 1:30,000. This assay can detect approximately 1 x 10(4) colony-forming units (CFU). This IBA has been used routinely to identify mycoplasmal isolates from 132 infected cell cultures. In addition, the procedure successfully detected Mycoplasma pneumoniae in throat swabs from patients with respiratory illness within 2 h. Perfect correlation was obtained with the IBA and microbiological culture of throat swabs for M. orale, M. salivarium and M. pneumoniae. The procedure was successfully used for other Mollicutes. It detected ureaplasmas in urogenital swabs and corn stunt spiroplasmas in infected corn plants and leafhoppers. A modification of the technique has been developed that identifies mycoplasma colonies on agar. It has also been used to assay for antimycoplasma antibodies in serum.