Technique for guiding catheter exchange during coronary angioplasty while maintaining guidewire access across a coronary stenosis

This case report describes a technique for guiding catheter exchange while angioplasty extended guidewire access is maintained across a coronary artery stenosis with a 245-cm-0.035-in.-long wire in the aorta to exchange for a more favorable guiding catheter. The indications, technique, and outcome of a case are described; it illustrates the usefulness of maintaining angioplasty guidewire access in a difficult-to-cross coronary stenosis.

Double-wire angioplasty of the right coronary artery bifurcational stenosis

Two cases of distal right coronary artery (RCA) bifurcational stenoses involving ostia of the posterolateral (PLA) and the posterior descending (PDA) branches in patients who underwent successful coronary angioplasty using a double-wire technique are reported. A single guiding catheter and sequential balloon inflations were utilized in one, and two guiding catheters and simultaneous balloon inflations in the other. The indications, techniques, and outcomes are described.

A Modified Screening Test for Determining Heterodera glycines Resistance in Soybean

A modified version of a standard greenhouse bioassay for determining soybean cyst resistance in soybean plants is described. White plastic laundry tubs served as microplots for rearing large numbers of nematodes in a confined space; up to 3 million eggs of each generation were collected per tub. Before screening, SCN populations were evaluated on susceptible and resistant soybean to characterize female development; these were periodically retested. Screening tests took place in Todd planter flats (120 plants per flat). Test plants were inoculated with 1,200 eggs per plant and evaluated for resistance 33-37 days after inoculation. The plants were pruned at the cotyledonary node which resulted in a greatly reduced root system. Staining the roots in Toluidine Blue created contrast with the white females and facilitated counting. Greenhouse space was conserved, and the labor to set up and maintain the screening test was reduced.

Psychologic aspects of flatulent dyspepsia

Psychologic and social factors have been implicated in the aetiology of dyspepsia. In this study these factors were investigated in relation to flatulent dyspepsia, a symptom complex that has traditionally been associated with gallbladder disease. Subjects completed the Middlesex Hospital Questionnaire and the Life Events Inventory and were interviewed in detail, using a semi-structured format. Three groups of patients with flatulent dyspepsia--those with and without gallbladder disease and post-cholecystectomy--all had significantly more associated somatic symptoms than non-dyspeptic subjects with gallbladder disease or normal controls, thus indicating greater emotional upset amongst dyspeptic patients. There was little evidence that symptoms were related to stressful life events.

Interaction between Meloidogyne incognita and Hoplolaimus columbus on Davis Soybean

Greenhouse and laboratory experiments were performed to determine if an interaction exists between Meloidogyne incognita and Hoplolaimus columbus on Davis soybean. Greenhouse tests were performed with three population levels of M. incognita and H. columbus (0, 1,500, 6,000/1.5-liter pot) separately and in all combinations. Dry root weight (DRT) declined nonlinearly and dry shoot weight (DST) declined linearly with respect to increasing initial populations of M. incognita and H. columbus. When the two nematode species were added to the soil together, the amount of DRT and DST suppression by one species was dependent on the initial level of the concomitant species. The final root population of M. incognita or H. columbus declined linearly with increasing initial population density of the concomitant species. H. columbus suppressed M. incognita populations in the soil nonlinearly, but M. incognita had no effect on H. columbus.

Free intermingling of mammalian beta-tubulin isotypes among functionally distinct microtubules

Mammalian cells express a spectrum of tubulin isotypes whose relationship to the diversity of microtubule function is unknown. To examine whether different isotypes are segregated into functionally distinct microtubules, we generated immune sera capable of discriminating among the various naturally occurring beta-tubulin isotypes. Cloned fusion proteins encoding each isotype were used first to tolerogenize animals against shared epitopes, and then as immunogens to elicit a specific response. In experiments using these sera, we show that there is neither complete nor partial segregation of beta-tubulin isotypes: both interphase cytoskeletal and mitotic spindle microtubules are mixed copolymers of all expressed beta-tubulin isotypes. Indeed, a highly divergent isotype normally expressed only in certain hematopoietic cells is also indiscriminately assembled into all microtubules both in their normal context and when transfected into HeLa cells.

Schistosoma mansoni: immunogenic glycoproteins of the cercarial glycocalyx

Immunochemical studies at the level of the light and electron microscope showed that a monoclonal antibody, 128C3/3, was directed to an epitope in the glycocalyx of Schistosoma mansoni cercariae. Immunoprecipitation of surface labeled cercarial extracts with this monoclonal antibody demonstrated that the glycocalyx is composed of at least five components, including a very large molecular size polypeptide and polypeptides of 220, 180, 170, and 15 kDa. After transformation of cercariae to schistosomula, these polypeptides were shed from the surface and were therefore no longer accessible to surface labeling. Monoclonal antibody 128C3/3 was also reactive with a 38 kDa polypeptide from schistosomula; this polypeptide was weakly expressed on the surface of cercariae. Analysis of immunoprecipitates of radioiodinated protein extracts of cercariae, newly transformed schistosomula, and 36 hr in vitro cultured schistosomula showed that the 180 and 170 kDa polypeptides continued to be expressed within the organism following transformation, but were not accessible to surface labeling. Lectin binding studies revealed differences in the oligosaccharide composition of the six polypeptides. With the exception of the 15 kDa antigen, all the polypeptides reactive with 128C3/3 were highly immunogenic in infected mice and humans.

Contrast injection bradycardia during coronary angiography: effects in the denervated human heart

To assess the contribution of cardiac innervation toward understanding the mechanisms of bradycardia during contrast coronary angiography, heart rate (HR) responses in eight patients after heart transplantation were compared with 10 normal patients (control), 10 patients with coronary artery disease (CAD) and normal ventricular function, and 10 patients with congestive cardiomyopathy and normal coronary arteries. The longest P-P interval was measured beat to beat before (HR 1) and after (HR 2) coronary angiography. The coronary vessel perfusing the sinus node did not influence HR 2 responses within each group. HR 1 was significantly different from HR 2 (p less than 0.05) in the control and CAD groups but was not different in the transplant and cardiomyopathy groups. Compared with the control group, the percent decrease in HR was significantly less in transplant patients than in patients with cardiomyopathy. Thus contrast injection bradycardia is absent in denervated patients after heart transplant, and this response is markedly blunted in cardiomyopathy patients who are known to have diminished vasodepressor reflexes. These findings suggest that the bradycardia response is probably a neurally mediated phenomenon.

The mammalian beta-tubulin repertoire: hematopoietic expression of a novel, heterologous beta-tubulin isotype

We describe the structure of a novel and unusually heterologous beta-tubulin isotype (M beta 1) isolated from a mouse bone marrow cDNA library, and a second isotype (M beta 3) isolated from a mouse testis cDNA library. Comparison of M beta 1 and M beta 3 with the completed (M beta 4, M beta 5) or extended (M beta 2) sequence of three previously described beta-tubulin isotypes shows that each includes a distinctive carboxy-terminal region, in addition to multiple amino acid substitutions throughout the polypeptide chain. In every case where a mammalian interspecies comparison can be made, both the carboxy-terminal and internal amino acid substitutions that distinguish one isotype from another are absolutely conserved. We conclude that these characteristic differences are important in determining functional distinctions between different kinds of microtubule. The amino acid homologies between M beta 2, M beta 3, M beta 4, and M beta 5 are in the range of 95-97%; however the homology between M beta 1 and all the other isotypes is very much less (78%). The dramatic divergence in M beta 1 is due to multiple changes that occur throughout the polypeptide chain. The overall level of expression of M beta 1 is low, and is restricted to those tissues (bone marrow, spleen, developing liver and lung) that are active in hematopoiesis in the mouse. We predict that the M beta 1 isotype is functionally specialized for assembly into the mammalian marginal band.

Six mouse alpha-tubulin mRNAs encode five distinct isotypes: testis-specific expression of two sister genes

Five mouse alpha-tubulin isotypes are described, each distinguished by the presence of unique amino acid substitutions within the coding region. Most, though not all of these isotype-specific amino acids, are clustered at the carboxy terminus. One of the alpha-tubulin isotypes described is expressed exclusively in testis and is encoded by two closely related genes (M alpha 3 and M alpha 7) which have homologous 3' untranslated regions but which differ at multiple third codon positions and in their 5' untranslated regions. We show that a subfamily of alpha-tubulin genes encoding the same testis-specific isotype also exists in humans. Thus, we conclude that the duplication event leading to a pair of genes encoding a testis-specific alpha-tubulin isotype predated the mammalian radiation, and both members of the duplicated sequence have been maintained since species divergence. A second alpha-tubulin gene, M alpha 6, is expressed ubiquitously at a low level, whereas a third gene, M alpha 4, is unique in that it does not encode a carboxy-terminal tyrosine residue. This gene yields two transcripts: a 1.8-kilobase (kb) mRNA that is abundant in muscle and a 2.4-kb mRNA that is abundant in testis. Whereas the 1.8-kb mRNA encodes a distinct alpha-tubulin isotype, the 2.4-kb mRNA is defective in that the methionine residue required for translational initiation is missing. Patterns of developmental expression of the various alpha-tubulin isotypes are presented. Our data support the view that individual tubulin isotypes are capable of conferring functional specificity on different kinds of microtubules.

Urinary kallikrein: a physiological regulator of epithelial Na+ absorption

The apical membrane of the mammalian urinary bladder contains two populations of ionic conductances--one Na+ selective and amiloride blockable, the other cation selective and amiloride insensitive (a leak channel). Addition of kallikrein (an enzyme of unknown function normally found in urine) to the mucosal solution of the mammalian urinary bladder epithelium resulted in the loss (over a 2-hr period) of amiloride-sensitive Na+ current and an increase in the leak current that is amiloride insensitive. The rate of hydrolysis of Na+ channels is a first-order process that is concentration (activity) dependent and described by simple Michaelis-Menten kinetics with a maximum rate of 9.5 X 10(-3) min-1. At the activities measured in human urine, the corresponding rate constant will decrease Na+ channel density by 99.5% in 24 hr. Amiloride protects the amiloride-sensitive Na+ channels from degradation but not the leak pathway. The rate of hydrolysis of the leak pathway as well as the kinetics of hydrolysis are the same as that described for the Na+ channel. Of interest is that the leak pathway is hydrolyzed into a form that seems to partition between the apical membrane and mucosal solution (an unstable leak pathway). These results and previous findings suggest a regulatory role for kallikrein in salt and water homeostasis.

Brain-specific expression of MAP2 detected using a cloned cDNA probe

We describe the isolation of a set of overlapping cDNAs encoding mouse microtubule associated protein 2 (MAP2), using an anti-MAP antiserum to screen a mouse brain cDNA expression library cloned in bacteriophage lambda gt11. The authenticity of these clones was established by the following criteria: (a) three non-identical clones each expressing a MAP2 immunoreactive fusion protein were independently isolated from the expression library; each of these clones cross-hybridized at the nucleic acid level; (b) anti-MAP antiserum was affinity purified using nitrocellulose-bound fusion protein; these antibodies detected only MAP2 in an immunoblot experiment of whole brain microtubule protein; (c) a series of cDNA "walking" experiments was done so as to obtain a non-overlapping cloned fragment corresponding to a different part of the same mRNA molecule. Upon subcloning this non-overlapping fragment into plasmid expression vectors, a fusion protein was synthesized that was immunoreactive with an anti-MAP2 specific antiserum. Thus, a single contiguous cloned mRNA molecule encodes at least two MAP2-specific epitopes; (d) the cloned cDNA probes detect an mRNA species in mouse brain that is of a size (approximately 9 kb) consistent with the coding capacity required by a 250,000-D protein. The MAP2-specific cloned cDNA probes were used in RNA blot transfer experiments to assay for the presence of MAP2 mRNA in a variety of mouse tissues. Though brain contained abundant quantities of MAP2 mRNA, no corresponding sequences were detectable in RNA prepared from liver, kidney, spleen, stomach, or thymus. We conclude that the expression of MAP2 is brain-specific. Use of the MAP2 specific cDNA probes in genomic Southern blot transfer experiments showed the presence of a single gene encoding MAP2 in mouse. The microheterogeneity of MAP2 is therefore ascribable either to alternative splicing within a single gene, or to posttranslational modification(s), or both. Under conditions of low stringency, the mouse MAP2 cDNA probe cross-hybridizes with genomic sequences from rat, human, and (weakly) chicken, but not with sequences in frog, Drosophila, or sea urchin DNA. Thus, there is significant interspecies divergence of MAP2 sequences. The implications of the above observations are discussed in relationship to the potential biological function of MAP2.

A cloned cDNA encoding MAP1 detects a single copy gene in mouse and a brain-abundant RNA whose level decreases during development

Screening of a bacteriophage lambda gt11 cDNA expression library with a polyclonal anti-microtubule associated protein (MAP) antiserum resulted in the isolation of two non-cross-hybridizing sets of cDNA clones. One set was shown to encode MAP2 (Lewis, S. A., A. Villasante, P. Sherline, and N. J. Cowan, 1986, J. Cell Biol., 102:2098-2105). To determine the specificity of the second set, three non-overlapping fragments cloned from the same mRNA molecule via a series of "walking" experiments were separately subcloned into inducible plasmid expression vectors in the appropriate orientation and reading frame. Upon induction and analysis by immunoblotting, two of the fusion proteins synthesized were shown to be immunoreactive with an anti-MAP1-specific antibody, but not with an anti-MAP2-specific antibody. Since these MAP1-specific epitopes are encoded in non-overlapping cDNAs cloned from a single contiguous mRNA, these clones cannot encode polypeptides that contain adventitiously cross-reactive epitopes. Furthermore, these cDNA clones detected an abundant mRNA species of greater than 10 kb in mouse brain, consistent with the coding requirement of a 350,000-D polypeptide and the known abundance of MAP1 in that tissue. The MAP1-specific cDNA probes were used in blot transfer experiments with RNA prepared from brain, liver, kidney, stomach, spleen, and thymus. While detectable quantities of MAP1-specific mRNA were observed in these tissues, the level of MAP1 expression was approximately 500-fold lower than in brain. The levels of both MAP1-specific and MAP2-specific mRNAs decline in the postnatal developing brain; the level of MAP1-specific mRNA also increases slightly in rat PC12 cells upon exposure to nerve growth factor. These surprising results contrast sharply with reported dramatic developmental increases in the amount of MAP1 in brain and in nerve growth factor-induced PC12 cells. The cDNA clones encoding MAP1 detect a single copy sequence in mouse DNA, even under conditions of low stringency that would allow the detection of related but mismatched sequences. The cDNAs cross-hybridize with genomic sequences in rat, human, and chicken DNA, but not with DNA from frog, Drosophila, or sea urchin. These data are discussed in terms of the evolution and possible biological role of MAP1.

Anomalous placement of introns in a member of the intermediate filament multigene family: an evolutionary conundrum

The origin of introns and their role (if any) in gene expression, in the evolution of the genome, and in the generation of new expressed sequences are issues that are understood poorly, if at all. Multigene families provide a favorable opportunity for examining the evolutionary history of introns because it is possible to identify changes in intron placement and content since the divergence of family members from a common ancestral sequence. Here we report the complete sequence of the gene encoding the 68-kilodalton (kDa) neurofilament protein; the gene is a member of the intermediate filament multigene family that diverged over 600 million years ago. Five other members of this family (desmin, vimentin, glial fibrillary acidic protein, and type I and type II keratins) are encoded by genes with six or more introns at homologous positions. To our surprise, the number and placement of introns in the 68-kDa neurofilament protein gene were completely anomalous, with only three introns, none of which corresponded in position to introns in any characterized intermediate filament gene. This finding was all the more unexpected because comparative amino acid sequence data suggest a closer relationship of the 68-kDa neurofilament protein to desmin, vimentin, and glial fibrillary acidic protein than between any of these three proteins and the keratins. It appears likely that an mRNA-mediated transposition event was involved in the evolution of the 68-kDa neurofilament protein gene and that subsequent events led to the acquisition of at least two of the three introns present in the contemporary sequence.

Basolateral K channels in an insect epithelium. Channel density, conductance, and block by barium

K channels in the basolateral membrane of insect hindgut were studied using current fluctuation analysis and microelectrodes. Locust recta were mounted in Ussing-type chambers containing Cl-free saline and cyclic AMP (cAMP). A transepithelial K current was induced by raising serosal [K] under short-circuit conditions. Adding Ba to the mucosal (luminal) side under these conditions had no effect; however, serosal Ba reversibly inhibited the short-circuit current (Isc), increased transepithelial resistance (Rt), and added a Lorentzian component to power density spectra of the Isc. A nonlinear relationship between corner frequency and serosal [Ba] was observed, which suggests that the rate constant for Ba association with basolateral channels increased as [Ba] was elevated. Microelectrode experiments revealed that the basolateral membrane hyperpolarized when Ba was added: this change in membrane potential could explain the nonlinearity of the 2 pi fc vs. [Ba] relationship if external Ba sensed about three-quarters of the basolateral membrane field. Conventional microelectrodes were used to determine the correspondence between transepithelially measured current noise and basolateral membrane conductance fluctuations, and ion-sensitive microelectrodes were used to measure intracellular K activity (acK). From the relationship between the net electrochemical potential for K across the basolateral membrane and the single channel current calculated from noise analysis, we estimate that the conductance of basolateral K channels is approximately 60 pS, and that there are approximately 180 million channels per square centimeter of tissue area.

Tubulin pseudogenes as markers for hominoid divergence

Processed pseudogenes arise via unimolecular events that result in the integration of nonfunctional (and therefore non-selected) regions of DNA into the germ line. The sequence of such pseudogenes can be used as a novel form of evolutionary clock: the older a particular pseudogene, the more mutations it has acquired relative to the selectively constrained functional gene from which it was originally derived. We have used specific beta-tubulin gene probes to assay for the presence of fully sequenced processed pseudogenes in genomic DNA from various hominoid species. The data suggest that orangutan is more closely related to human, chimpanzee and gorilla than is generally believed.

Interrelationships of Meloidogyne arenaria and M. incognita on Tolerant Soybean

Reproduction of Meloidogyne arenaria race 2 was excellent on Centennial, Govan, and Kirby soybeans, the latter two of which have tolerance to this species. The M. incognita race 1 isolate reproduced poorly on Centennial, especially at the higher of two temperature regimes. Numbers of galls and egg masses of M. arenaria plus M. incognita in simultaneous equivalent infestations on Centennial did not differ from sequential infestations in which M. arenaria was added first and M. incognita was added to the same pots, 1,2, or 3 weeks later. However, at both 25 and 30 C, suppression of galls and egg masses occurred when inoculation of M. incognita preceded that of M. arenaria by 2 weeks. Generally, M. arenaria reproduced well at 25 or 30 C, whereas M. incognita reproduced better at 30 C. Kirby was tolerant to either nematode species at 25 and 30 C, but in combined infestations of M. arenaria and M. incognita there was evidence of synergistic growth suppression. Govan was tolerant of M. arenaria at 25 C but not at 30 C. Moreover, general plant growth was less vigorous for Govan at the higher temperature, whereas Centennial was much more vigorous at this temperature. Kirby grew equally well at both temperatures.

Coronary angioplasty of multiple vessels: short-term outcome and long-term results

Experience with percutaneous transluminal coronary angioplasty (PTCA) of multiple vessels was reviewed to assess short-term outcome and long-term results. PTCA of multiple vessels was performed in 100 of the initial 500 patients (20%) who underwent PTCA at the Medical College of Virginia between July 1979 and August 1984. Eighty-nine percent had class 3 or 4 angina, and 66% had unstable angina. Two-thirds had severe stenosis of two vessels or major branches and one-third had three-vessel disease. One or more significant lesions were dilated in two vessels in 84 patients, in three vessels in 14 patients, and in four vessels in two patients. PTCA of 273 lesions (2.7/patient) was attempted (range two to eight per patient) with angiographic success in 250 lesions (91.6%). Primary success (angiographic and clinical improvement) was achieved in 95 of 100 patients (95%); 84% had success in multiple vessels, and 79% had success in all attempted lesions. Complications occurred in 11 patients (11%); four patients (4%) underwent urgent bypass surgery and four additional patients (4%) had myocardial infarction. Long-term results were assessed in 44 patients with primary success who had follow-up of more than 1 year (mean 26 months) after multiple-vessel PTCA. Twenty-eight patients (64%) remain event-free and improved and 48% are event-free and asymptomatic. Clinical recurrence developed in 15 patients (34%); four had sustained improvement with repeat PTCA, three remain improved with medical therapy, and eight (18%) have undergone bypass surgery during follow-up. One patient (2.3%) developed late myocardial infarction, and deaths have occurred in the follow-up cohort.(ABSTRACT TRUNCATED AT 250 WORDS)

Host-Parasite Relationships of Meloidogyne arenaria and M. incognita on Susceptible Soybean

Pathogenicity and reproduction of single and combined populations of Meloidogyne arenaria and M. incognita on a susceptible soybean (Glycine max cv. Davis) were investigated. Significant galling and egg mass production were observed on roots of greenhouse-grown soybean inoculated with M. arenaria and M. incognita, in combination and individually. M. arenaria produced more galls and egg masses than M. incognita, whereas in combined inoculation with both nematode species, gall and egg production was intermediate. In growth chamber tests, inoculations with M. arenaria and M. incognita, singly or in combination, produced more galls and egg masses at 30 C than at 25 C. At 25 C, M. arenaria alone produced significantly more galls and egg masses than the combined M. arenaria plus M. incognita, while M. incognita produced the fewest. At 30 C, numbers of egg masses produced by M. arenaria did not differ significantly from combined M. arenaria and M. incognita. In temperature tank tests, M. incognita produced more galls and egg masses at 28 C than at 24 C soil temperature. In contrast, numbers of galls, egg masses, and eggs of M. arenaria were slightly higher at 24 C than at 28 C. Combined inoculum of both nematode species produced greater numbers of galls at 24 C than at 28 C.