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R McKay

Publications and source records attributed to R McKay.

At least 109 records · Page 6Linked to original sources
PubMed1988

Monoclonal antibodies reveal cell-type-specific antigens in the sexually dimorphic olfactory system of Manduca sexta. I. Generation of monoclonal antibodies and partial characterization of the antigens.

The olfactory system of the moth Manduca sexta is sexually dimorphic. Male moths possess a male-specific olfactory "subsystem," comprising olfactory receptor cells (ORCs) and CNS neurons and synaptic areas associated with the detection of female sex pheromones, in addition to elements common to males and females. In order to explore the molecular differences between cells that subserve the sexual dimorphism and odor-specificity of components of the olfactory system, we generated monoclonal antibodies (Mabs) against tissue of the olfactory system of the moth. In 2 fusions, we screened 1105 hybridoma lines and obtained 272 lines that secreted antibodies against Manduca nervous tissue, as assayed immunocytochemically on sections of the primary olfactory center (the antennal lobe) in the brain of Manduca. We describe here 3 classes of Mabs exemplifying the several cell-type-specific antibodies obtained through the screening procedure. Seven hybridoma lines secrete antibodies that specifically recognize cell bodies, axons, and initial segments of dendrites of many or all ORCs of both males and females (classified as olfactory-specific antibodies, OSAs). Electron-microscopic studies of 2 of the Mabs in this class showed that they recognize antigens associated with the cell membrane and that the immunoreactive ORC axons are bundled together in fascicles in the antennal nerve. On immunoblots, one of the OSA Mabs recognizes 3 distinct protein bands of apparent Mrs 42,000, 59,000, and 66,000 Da. When tissue samples enriched in either receptor cell bodies, dendrites, and initial segments of axons or in distal segments of axons and their terminals and synapses were extracted separately, different patterns of bands were detected--42,000 and 59,000 Da bands from cell bodies and initial segments of axons and dendrites, and 42,000 and 66,000 Da bands from distal segments of axons and their terminals--suggesting that the 59,000 Da protein is modified to the 66,000 Da protein during axonal transport. The second Mab we describe here, the male olfactory-specific antibody (MOSA), selectively recognizes the sexually dimorphic ORCs that are present only in males. The antigen recognized by this antibody is found in cell bodies, dendrites, axons, and axon terminals. By electron-microscopic immunocytochemistry, the MOSA immunoreactivity is found in the cytoplasm and appears not to be associated with particular subcellular organelles. This antibody demonstrates that male-specific ORCs are molecularly distinct from other types of ORCs.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1988

Monoclonal antibodies reveal cell-type-specific antigens in the sexually dimorphic olfactory system of Manduca sexta. II. Expression of antigens during postembryonic development.

Two classes of monoclonal antibodies specific to the olfactory system of Manduca sexta have been isolated: the olfactory-specific antibody (OSA), which specifically recognizes many or all olfactory receptor cells (ORCs) in both males and females, and the male olfactory-specific antibody (MOSA), which stains male-specific receptor cells (principally or exclusively sex-pheromone receptors present only in antennae of males; Hishinuma et al., 1988). In the investigation reported here, we examined the expression of the antigens during postembryonic development in order to correlate the presence of particular antigens with the status of differentiation of the ORCs or with their acquisition of particular functions. As assessed immunocytochemically, the OSA recognizes certain epithelial cells in the antennal imaginal disk of the fifth-instar larva. Later, during the first 70 hr of adult development, when differentiative cell divisions are occurring in the antennal epithelium to generate ORCs and the other cells that make up olfactory sensilla, no cells are stained. Immediately after this period of mitoses, the OSA immunoreactivity reappears exclusively in the ORCs, which begin to elaborate axons as an early event in their differentiation. On immunoblots, the OSA recognizes specific sets of molecules (distinguished on the basis of their apparent molecular weights): 53,000 and 59,000 Da antigens in the disk epithelial cells in the last-instar larva; 53,000, 59,000, and 66,000 Da antigens in the ORCs from 15 to 60% of metamorphic adult development; and 42,000, 59,000, and 66,000 Da antigens in the ORCs from 60 to 100% of adult development. The MOSA also recognizes a subset of the epithelial cells in the antennal disks in male and female larvae.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1986

Hemodynamic determinants of thallium-201 lung uptake in patients during atrial pacing stress.

The present investigation was undertaken to define the hemodynamic determinants of lung uptake of thallium-201 (TI-201) in man during stress. Graded tachycardia was induced by atrial pacing with continuous hemodynamic monitoring in 21 patients (6 normal, 15 with coronary artery disease). At peak pacing, 80 MEq (2.2 mCi) of TI-201 was injected intravenously and imaging commenced within 5 minutes. Lung activity was expressed as a percentage of peak myocardial activity on the anterior image (Lung TI-201 Index). The influence of rest, peak and post pacing hemodynamic parameters including cardiac index, pulmonary capillary wedge pressure, left ventricular end-diastolic pressure, pulmonary artery pressure, and heart rate on Lung TI-201 Index was examined using step-wise multiple regression. Change in cardiac index from rest to peak pacing was negatively correlated, while pulmonary capillary wedge pressure at peak pacing was positively correlated to Lung TI-201 Index (combined r value of 0.75). No other parameter had a significant correlation. In summary, lung uptake of TI-201 activity during atrial pacing stress appears to depend on: changes in cardiac output which may determine tissue contact time and thus influence extraction efficiency, and hydrostatic pressure in the pulmonary capillary bed.

Adult↗
PubMed1986

An anatomical study of the patterns of the coronary arteries and sinus nodal artery in complete transposition.

The origin and course of the main coronary arteries and the sinus nodal artery are relevant to both intra-atrial and arterial relocation operations for complete transposition (the combination of concordant atrioventricular and discordant ventriculo-arterial connexions). The patterns of the main coronary arteries in 148 hearts with complete transposition have been documented together with the patterns of the sinus nodal artery in 105 of these. The terminology which has been used to describe these arteries has been explained. The findings illustrate the wide variation which exists in the origin and course of all these arteries in complete transposition and indicate areas where they are most at risk.

Arteries↗
PubMed1986

Misleading hyperoxia test.

A 2 day old infant with infracardiac total anomalous pulmonary venous connection achieved an arterial oxygen tension greater than 250 mmHg, breathing 100% oxygen. Diagnosis of cardiac disease was delayed several weeks. The anatomical basis for this phenomenon was streaming of systemic venous return across an inferior vena cava type atrial septal defect.

Coronary Vessel Anomalies↗
PubMed1986

Staged septation of double inlet left ventricle.

Complete septation of a double inlet left ventricle with left anterior subaortic outlet chamber was carried out successfully as a staged procedure during the first two years of life in a patient with severe pulmonary hypertension and an abnormal left atrioventricular valve. In contrast with isolated pulmonary artery banding, which rarely has led to a satisfactory septation or modified Fontan operation, this technique achieved good initial palliation and uncomplicated intracardiac repair. It should be considered for infants with univentricular atrioventricular connection, two atrioventricular valves, and excessive pulmonary blood flow.

Female↗
PubMed1986

Double connections in total anomalous pulmonary venous connection.

Three infants who underwent operation for total anomalous pulmonary venous connection had unobstructed drainage of all the pulmonary veins to both the coronary sinus and left vertical vein. In one patient the anatomy was demonstrated preoperatively and complete correction accomplished without difficulty, but in two patients the second connection was discovered only at postoperative reinvestigation. Arbitrary classification of total anomalous pulmonary venous connection into cardiac, supracardiac, infracardiac, and mixed types does not lend itself to description of such lesions and may obscure their clinical importance. For these less common variants of total anomalous pulmonary venous connection, a more detailed and precise definition of morphology facilitates accurate surgical repair.

Cardiac Catheterization↗
PubMed1985

A complicated case of mitral valve disease.

A patient with rheumatic mitral stenosis and previous cerebral embolism had a myocardial infarction during cardiac catheterisation. She later developed severe mitral regurgitation one year after open valvotomy and at valve replacement was found to have a papillary tumour of the mitral valve. Unexplained low cardiac output occurred four days after operation. Postmortem examination showed thrombotic occlusion of the xenograft prosthesis, a complication not previously seen with tissue valves. Both of these rare events were suggested by the patient's clinical course and could have been diagnosed with cross sectional echocardiography.

Bioprosthesis↗
PubMed1984

Monoclonal antibody identifies a 63,000 dalton antigen found in all central neuronal cell bodies but in only a subset of axons in the leech.

The monoclonal antibody Lan3-8 binds to all the neuronal cell bodies in midbody, head, tail, and supraesophageal ganglia in the mud leech (Haemopis marmorata) and the medicinal leech (Hirudo medicinalis). In contrast to the general distribution of the antigen in cell bodies it is only found in a subset of axons, where electron microscopy suggests that it may be associated with a cytoskeletal filament system. Immunoblotting shows that the antibody binds to a 63,000 dalton band that is protease-sensitive. The same 63 kilodalton (kd)-antigen is found in all regions of the central nervous system, in proteins isolated from connectives (axons alone), and from hand-dissected identified cell types. The molecular weight and electron microscopic localization raised the possibility that this antigen is the core neurofilament protein, but the antigen does not comigrate with 67-kd intense coomassie blue band that binds another anti-intermediate filament antibody. The supraesophageal ganglia are known to have a different developmental or origin from the other structures in the leech central nervous system. Two-dimensional gel electrophoresis and silver staining show that, like the 63-kd antigen, many other proteins are very similar in these developmentally distinct neural structures.

Animals↗
PubMed1983

Immunoassay for sequence-specific DNA-protein interaction.

An immunoassay that allows a quantitative measure of the interaction of DNA and specific DNA binding proteins has been described here. A detailed quantitative description of the assay has previously been published. In this chapter the assay has been used to determine the size and location of the SV40 sequences that bind the viral protein, T antigen, by new DNase protection and footprinting procedures. These results are consistent with the observations of Tjian, who used purified protein to establish the sizes and locations of T-antigen binding sites. In addition, the assay is shown to be capable of detecting specific binding even in crude protein extracts of SV40 virus-transformed cell lines that carry only one copy of the viral genome. These results suggest that this procedure may be useful in the identification and purification of specific DNA binding proteins in eukaryotic cells.

Animals↗
PubMed1983

Monoclonal antibodies demonstrate the organization of axons in the leech.

Monoclonal antibodies have been generated that bind to subsets of neurons within the leech central nervous system (Zipser, B., and R. McKay (1981) Nature 289: 549-554). In this report we describe the binding patterns of monoclonal antibodies to subsets of axons in the leech using HRP-immunohistochemistry. Each antibody has a characteristic staining pattern in the connective, the large bundle of axons that runs the length of the nerve cord connecting each ganglion to its rostral and caudal neighbors. These staining patterns are consistent along the rostrocaudal axis of each animal, between animals of the same species, and, in many cases, between animals of different species. These results show that axonal position, like neuron cell body position, is a consistent feature of the organization of the leech central nervous system. Two antibodies bind to all of the axons in particular fascicles that are delimited by glial cell processes; another binds to single axons in fascicles that contain other, unstained axons. The grouping of antibody-identified axons into fascicles does not correlate in a simple way with the grouping of neuron cell bodies identified with the same antibody. The presence of one of these antigens on the surface of axons suggests a possible role in axon fasciculation. This report shows that molecular heterogeneity is a property of axons as well as of neuron cell bodies and demonstrates the organization of specific antibody-identified groups of axons within the connective.

Animals↗
PubMed1983

[Indications for the surgical correction in patients with transposition of the great arteries, intact interventricular septum and organic or functional obstruction of the outflow tract of the left ventricle. Analysis of 53 cases operated on by the Mustard technic].

Between January 1965 and December 1979, in our Unit 53 patients underwent Mustard's operation for TGA, intact ventricular septum and LVOTO. There were 35 males and 18 females, ranging in age from 27 days to 12 years (mean = 26 months) and in weight from 3.7 to 26 kg (mean = 9.6 Kg). Twenty-one infants had undergone previous palliative procedures. The degree of LVOTO was mild in 26 cases, moderate in 10 and severe in 17 patients. In 28 cases no distinct anatomical obstructions were identified. In the other 25 patients the obstruction occurred at various level and it was determined by several anatomical structures. Subvalvular fibromuscular narrowing, redundant mitral valve, valvular stenosis and subvalvular fibrous shelf were the commonest forms encountered. The LVOTO was managed in several different ways. In 28 patients in whom the gradient was judged to be functional, no surgical intervention at the level of the LVOT was attempted. In 8 cases, all operated on at the beginning of this experience, an anatomic obstruction was present but was considered too difficult to be resected and, therefore, was left untreated. In 9 patients the LVOT was inspected either through the pulmonary valve or from below, through a left ventriculotomy. Pulmonary valvotomy was carried out in 5 of these cases, resection of the subvalvular fibrous shelf in 3 and subvalvular fibromuscular tunnel resection in 1. In 6 patients a left ventricle to pulmonary artery conduit was used to bypass the obstruction. A fibromuscular tunnel type of obstruction was present in 5 of these cases, while in one the obstruction was mainly due to a redundant mitral valve.(ABSTRACT TRUNCATED AT 250 WORDS)

Child↗
PubMed1982

DNA intermediates in transposition of phage Mu.

Transposable genetic elements can insert into DNA sites that have no homology to themselves. Evidence that there is a physical linkage between a transposable element and its target DNA sequence during transposition comes from studies on bacteriophage Mu DNA transposition in which plasmids containing Mu DNA have been shown to attach to host DNA. We report the isolation of key structures, seen after induction of Mu DNA replication, after cloning lac operator into Mu DNA and using the lac repressor-operator interaction to trap Mu DNA on nitrocellulose filters. We have localized Mu sequences within these structures in the electron microscope by visualizing the lac operator-repressor interaction after binding with ferritin-conjugated antibody. This analysis shows that key structures contain replicating Mu DNA linked to non-Mu DNA and that replication can begin at either end of Mu.

Bacteriophage mu↗
PubMed1982

Unusual vascular ring in infant with pulmonary atresia and ventricular septal defect.

A 3-day-old infant investigated for cyanotic heart disease was found to have partial DiGeorge syndrome and pulmonary atresia with ventricular septal defect. The only source of pulmonary blood flow was a right-sided persistent ductus arteriosus which originated from an aberrant right subclavian artery. Such a vascular ring has not been described previously. Surgical treatment included a left-sided prosthetic shunt in infancy followed by resection of the ligamentum arteriosum and right subclavian artery during the second year of life.

DiGeorge Syndrome↗