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.

[In vitro studies of the cell cycle of mouse myelomonocytic leukemia using a fluorescence activated cell sorter and autoradiography]

Cell cycle and various phase time of mouse myelomonocytic leukemia cells were studied in vitro with Fluorescence Activated Cell Sorter (FACS 420, Becton-Dikinson FACS Systems, Sunnyvale, CA, USA) in testing cellular DNA content and with autoradiography. At the same time, doubling time was calculated by counting the number of cells cultured in vitro within 6 days following implantation. According to the cellular DNA content, the proportions of various cell phases in the whole cell population were as follows: G1, S and G2 plus M phases take up 30.5%, 47.9% and 21.6%. Basing on autoradiography and direct counting, the cell number, the cell cycle, duration of various cell phases and doubling time were as follows: LI = 98.0%, MI = 1.7 +/- 0.9%, TG1 = 4.9 hrs, TS = 8.0 hrs, TG2 = 2.8 hrs, Tm = 0.3 hr, TC = 16.0 hrs, TD = 17.0 hrs. FACS assay showed that the duration of various cell phases are quite similar to that calculated by autoradiography. Therefore a simple and rapid FACS method may be widely used in the studies of cell cycle instead of autoradiography if estimating computer program is available.

Deletion mapping of Sindbis virus DI RNAs derived from cDNAs defines the sequences essential for replication and packaging

Defective-interfering (DI) genomes of a virus contain sequence information essential for their replication and packaging. They need not contain any coding information and therefore are a valuable tool for identifying cis-acting, regulatory sequences in a viral genome. To identify these sequences in a DI genome of Sindbis virus, we cloned a cDNA copy of a complete DI genome directly downstream of the promoter for the SP6 bacteriophage DNA dependent RNA polymerase. The cDNA was transcribed into RNA, which was transfected into chicken embryo fibroblasts in the presence of helper Sindbis virus. After one to two passages the DI RNA became the major viral RNA species in infected cells. Data from a series of deletions covering the entire DI genome show that only sequences in the 162 nucleotide region at the 5' terminus and in the 19 nucleotide region at the 3' terminus are specifically required for replication and packaging of these genomes.

Upper- vs lower-limb systolic blood pressure in full-term normal newborns

The difference between upper- vs lower-limb systolic blood pressure (BP) was investigated in 100 normal full-term newborns younger than 24 hours of age by the oscillometric method. The mean systolic BP of both upper limbs was 72.3 +/- 7.6 mm Hg (mean +/- SD). The mean +/- SD systolic BP of both lower limbs was 71.3 +/- 8.2 mm Hg. Systolic BP in the upper limb was greater than that in the lower limb in 66% of newborns by as much as 20 mm Hg (mean +/- SD, 3.5 +/- 3.1). Systolic upper-limb BP was lower than systolic lower-limb BP in 28% of newborns by as much as 21 mm Hg (mean +/- SD, 5.1 +/- 5.1). Systolic BP did not correlate with birth weight. Follow-up evaluation of BP in 25 of the infants up to 3 years of age revealed higher systolic BP in the lower extremities in 24 of the 25 infants. We conclude that (1) it is normal to have a higher systolic BP in either the upper limb or the lower limb in newborns younger than 24 hours of age, and (2) there is no correlation of systolic BP with birth weight in full-term normal neonates younger than 24 hours of age.

Studies on Alternaria Allergens

The effects of an extract of the saprophytic mold, <i>Alternaria tenuis </i>(AT-CE) on the humoral response to a ragweed allergen extract (DWSR), ovalbumin and sheep red blood cells (SRBC) was investigated in female Wistar rats. Animals pretreated with 100 <i>μ</i>gor 2 mg AT-CE showed enhancement (p <0.05) in the reaginic response (IgE antibody) to DWSR at 25 and 18 days postimmunization. On the other hand, animals posttreated with AT-CE showed substantial reduction in anti-DWSR IgE antibody response. Contrasting results were obtained when ovalbumin was used as an immunizing antigen. There was a remarkable enhancement in the reaginic response to ovalbumin in rats pre- or posttreated with 10 <i>μ</i>gof AT-CE. Pretreatment with AT-CE did not affect the hemagglutination titers to ovalbumin, while posttreatment with 100 <i>μ</i>gor 1 mg AT-CE increased the hemagglutination titers of IgM antibody. There was a significant reduction in hemagglutinin, and hemolysin titers to SRBC in animals pretreated with all concentrations of AT-CE; at day 21, suppression was noted in animals pre- or posttreated with all concentrations of AT-CE. On the other hand, greatly increased hemagglutination titers were found in animals posttreated with 100 <i>μ</i>gor 1 mg AT-CE. Hence, enhancement and suppression can both occur depending on the dose and time of administration of AT-CE together with the nature of the immunizing antigen.

Prevention of hyaline membrane disease in premature lambs by apneic oxygenation and extracorporeal carbon dioxide removal

Hyaline membrane disease is found only in lungs where pulmonary ventilation has been established, i.e. after birth. We delivered eleven fetal lambs of a gestational age of 128-130 days but instead kept their lungs in total apnea and inflated to constant pressure, while removing all metabolically produced carbon dioxide with an extracorporeal membrane lung. Oxygen was provided by the membrane lung, and by apneic oxygenation through the natural lungs. Hence, arterial blood gases remained always normal, without any pulmonary ventilation. After 6-66 h the lungs had sufficiently cleared to allow normal mechanical pulmonary ventilation in 10 our of 11 lambs so treated. In a control group treated with mechanical ventilation alone, five of seven lambs died within the first 24 h of severe hyaline membrane disease.

An immunoglobulin heavy chain variable region gene is generated from three segments of DNA: VH, D and JH

We have determined the sequences of separate germline genetic elements which encode two parts of a mouse immunglobulin heavy chain variable region. These elements, termed gene segments, are heavy chain counterparts of the variable (V) and joining (J) gene segments of immunoglobulin light chains. The VH gene segment encodes amino acids 1-101 and the JH gene segment encodes amino acids 107-123 of the S107 phosphorylcholine-binding VH region. This JH gene segment and two other JH gene segments are located 5' to the mu constant region gene (Cmu) in germline DNA. We have also determined the sequence of a rearranged VH gene encoding a complete VH region, M603, which is closely related to S107. In addition, we have partially determined the VH coding sequences of the S107 and M167 heavy chain mRNAs. By comparing these sequences to the germline gene segments, we conclude that the germline VH and JH gene segments do not contain at least 13 nucleotides which are present in the rearranged VH genes. In S107, these nucleotides encode amino acids 102-106, which form part of the third hypervariable region and consequently influence the antigen-binding specificity of the immunoglobulin molecule. This portion of the variable region may be encoded by a separate germline gene segment which can be joined to the VH and JH gene segments. We term this postulated genetic element the D gene segment, referring to its role in the generation of heavy chain diversity. Essentially the same noncoding sequences are found 3' to the VH gene segment and as inverse complements 5' to two JH gene segments. These are the same conserved nucleotides previously found adjacent to light chain V and J gene segments. Each conserved sequence consists of blocks of seven and ten conserved nucleotides which are separated by a spacer of either 11 or 22 nonconserved nucleotides. The highly conserved spacing, corresponding to one or two turns of the DNA helix, maintains precise spatial orientations between blocks of conserved nucleotides. Gene segments which can join to one another (VK and JK, for example) always have spacers of different lengths. Based on these observations, we propose a model for variable region gene rearrangement mediated by proteins which recognize the same conserved sequences adjacent to both light and heavy chain immunoglobulin gene segments.

Pattern of follicular growth and steroidogenesis in the ovary of aging cycling rats

Prior to the cessation of reproductive cycles, older female rats exhibit irregular and prolonged cycles due to alterations in the hypothalamic-pituitary-ovarian axis. In order to evaluate the age-related changes in the ovary, the histology, and estradiol, testosterone and progesterone concentrations within the ovaries of mature regular cycling (4--5 mo. old) and older irregular cycling (10--11 mo. old) rats were examined. At estrus, the number of non-atretic growing follicles (150--300u in diameter) was greater in the mature than in the older rats (18 +/- 1.5 vs 4.5 +/- 1.4). However, the number of preovulatory follicles on proestrus did not differ (6.0 +/- 1.2 vs 5.5 +/- 0.6). Estradiol, testosterone and progesterone concentrations on proestrus in mature rats averaged 38.8 pg, 56.1 pg, and 1.0 ng/ml of ovary, respectively. In the older proestrous rat, only estradiol was altered, increasing to 124.3 pg/mg. In addition, many of the preovulatory follicles within the aged ovary were larger (greater than 600u in diameter) than those within the mature ovary. On the day of estrus virtually all preovulatory follicles ovulated in the mature rat, whereas large follicles, less than or equal to 600u in diameter, remained in the older ovary. In addition, estradiol levels remained elevated and ovarian cysts were observed in the aged ovary. Thus, in the older irregular cycling rat, 1) pre-ovulatory follicles develop, but many do not ovulate; 2) these non-ovulatory follicles form ovarian cysts which remain within the ovary. The number of cysts may increase with age until a polycystic ovary develops and the rat enters a constant estrous state.

Studies on Alternaria allergens. I. Isolation of allergens from Alternaria tenuis and Alternaria solani

Extracts of Alternaria tenuis and Alternaria solani were separated into dialyzable (molecular weight less than 10,000) and non-dialyzable forms. The latter was further fractionated by gel filtration through Sephadex G-100 followed by ion-exchange chromatography on DEAE-cellulose. The dialyzable material was fractionated by gel filtration through Sephadex G-50. The allergenic activities of the fractions obtained from the A. tenuis extract was measured in vitro by the radioallergosorbent test assay and the allergenic potency was measured by radioallergosorbent test inhibition assay. Allergenic activity was detected in most of the non-dialyzable fractions, the majority of the activity being in the last G-100 fraction (MW approximately 20,000) which was predominantly protein in nature. The same component may be responsible for the activity found in the dialyzate and its first G-50 fraction since the immunodiffusion studies indicated that the last G-100 fraction has antigenic components in common with those of the first G-50 fraction. In addition, cross-reactions between A. tenuis and A. solani extracts show that the two species share common antigenic determinants.