Search PubMed⌕ Search

Biomedical subjects

C R Bird

Publications and source records attributed to C R Bird.

At least 55 records · Page 3Linked to original sources
PubMed1988

The use of Tween 20 alone as a blocking agent for immunoblotting can cause artefactual results.

The use of Tween 20 as a suitable blocking agent in immunoblotting studies was evaluated by screening a panel of monoclonal antibodies (MoAbs) against a selection of blotted proteins which were unrelated to the antigens used to raise the MoAbs. Using Tween 20 alone to block the nitrocellulose membranes clear reactions were observed between the panel of MoAbs and several components of the blotted protein mixture. In contrast, when haemoglobin was used to block the membranes such reactions were not observed. In the absence of added protein the use of Tween 20 alone as a blocking agent for immunoblotting appears to lead to false positive reactions by non-specific antigen-antibody complexes.

Antibodies, Monoclonal↗
PubMed1988

Outpatient performance of invasive radiologic procedures in pediatric patients.

A retrospective review was done of the outcomes of 102 invasive radiologic procedures--including myelography, angiography and needle aspiration biopsy--performed on an outpatient basis in 94 pediatric patients. Four children had complications requiring visits to their physicians, but no patients required hospitalization after the procedure. With appropriate patient selection, invasive studies performed on an outpatient basis in infants, children, and adolescents are safe.

Adolescent↗
PubMed1988

Gd-DTPA-enhanced MR imaging in pediatric patients after brain tumor resection.

A prospective study was conducted in 15 pediatric patients who had undergone resection of intracranial tumors. The object of the study was to determine the safety and efficacy of magnetic resonance (MR) imaging performed after the administration of gadolinium diethylenetriamine-pentaacetic acid (Gd-DTPA) in evaluating residual or recurrent tumor. Precontrast T1-weighted, intermediate, and T2-weighted images were obtained at a field strength of 1.5 T. Gd-DTPA was then injected intravenously in a dose of 0.1 mmol per kilogram of body weight. T1-weighted images were obtained within 5 minutes after the injection, intermediate and T2-weighted images were obtained 10 minutes after the injection, and T1-weighted images were obtained approximately 20 minutes after the injection. None of the patients experienced allergic reactions or other side effects. Physical examination findings and laboratory values were unchanged after the Gd-DTPA-enhanced examination. In six patients, contrast-enhanced images depicted tumor not suspected on nonenhanced images. In four other patients, enhanced images provided better definition of the tumor core. The images of one patient with a brain stem tumor showed no evidence of enhancement. Pre- and postcontrast images of three previously treated patients showed no evidence of tumor. Gd-DTPA appears to be a safe and effective contrast agent for MR imaging and provides a more accurate method of imaging in the follow-up of brain tumors in pediatric patients.

Brain↗
PubMed1988

Gradient echo (GRASS) MR imaging in cervical radiculopathy.

Limited flip angle (LFA), gradient echo imaging was performed in 130 patients for evaluation of cervical radicular complaints. The LFA study was compared with myelography, CT myelography, and surgical results. Image quality was considered good or excellent for 128 patients. The use of a 10 degrees flip angle with a TR of 75 msec and TE of 12.3 msec consistently provided good contrast and signal-to-noise ratio, giving a CT myelographic effect. The use of both axial and sagittal LFA images was important for optimal detection of extradural defects and for distinction of herniated disk versus osteophyte. There was excellent correlation between the MR and surgical findings. Our results suggest that MR imaging is the initial procedure of choice for the evaluation of suspected cervical radiculopathy.

Cervical Vertebrae↗
PubMed1988

MR imaging of pericallosal lipoma.

Early pathologic reports of corpus callosal lipoma described a consistent relationship between the lipoma and the dorsal surface of the corpus callosum, particularly when the lipoma is not associated with corpus callosal agenesis. MR imaging, especially T1-weighted sagittal acquisitions, exquisitely demonstrated this anatomic relationship in three relatively asymptomatic patients. Therefore, in most cases, a lipoma of the corpus callosum is more accurately described as a pericallosal lipoma. In one individual, common associated findings (partial agenesis of the corpus callosum and choroid plexus lipoma) were also noted. Surgical therapy is usually not indicated because symptoms are generally not related and the anterior cerebral artery is often encased by the lipoma.

Adult↗
PubMed1988

Production of interleukin 1 in the joint during the development of antigen-induced arthritis in the rabbit.

Antigen-induced arthritis in the rabbit closely resembles rheumatoid arthritis. The levels of interleukin 1 (IL-1) in the synovial fluid and the synthesis of IL-1 by infiltrating cells in synovial fluid and by the synovial lining from control and inflamed joints has been assessed during the first month of this disease. A number of biological assays have been used to measure rabbit IL-1. Of these, only the assay using the murine thymoma cell line (EL-4 NOB-1) was able to detect IL-1 activity in the synovial fluid of arthritic joints, which was present only in the very early lesion. The leucocytes infiltrating the synovial cavity produced little IL-1 ex vivo in the acute lesion but released large amounts when arthritis was established. A similar finding was made with respect to the production of IL-1 by the synovial lining.

Animals↗
PubMed1987

A simple sensitive bioassay for interleukin-1 which is unresponsive to 10(3) U/ml of interleukin-2.

A subclone, NOB-1, of the mouse EL-4 line constitutively produces very little interleukin-2 but in response to interleukin-1 produces high concentrations of interleukin-2. Co-stimulation with mitogen, phorbol esters or calcium ionophores was not required. NOB-1 is not responsive to tumour necrosis factor alpha, tumour necrosis factor beta, interferon gamma and lipopolysaccharide. The NOB-1 line was used in conjunction with a CTLL line to detect less than 1 pg/ml interleukin-1. Rapid assay was performed by co-culturing the EL-4 cells with CTLL cells. By incorporating a pre-incubation step, followed by thorough washing of the EL-4 cells, responses to interleukin-1 were maintained, but interleukin-2 had no effect. The assay was used to detect interleukin-1 in serum samples and to evaluate neutralizing antisera to interleukin-1.

Animals↗
PubMed1987

Structure and expression of an ethylene-related mRNA from tomato.

Messenger RNAs homologous to a cDNA clone (pTOM 13) derived from a ripe-tomato-specific cDNA library are expressed during tomato fruit ripening and after the wounding of leaf and green fruit material. Both responses involve the synthesis of the hormone ethylene. Accumulation of the pTOM 13--homologous RNA during ripening is rapid and sustained, and reaches its maximum level in orange fruit. Following mechanical wounding of tomato leaves a pTOM 13--homologous RNA shows rapid induction within 30 minutes, which occurs before maximal ethylene evolution (2-3 h). This RNA also accumulates following the wounding of green tomato fruit. Northern blot analysis of poly(A)+ RNA indicates that the length of the mRNA is about 1400 nucleotides. Nucleotide sequence analysis showed the cDNA insert to contain the complete coding region of the pTOM 13 protein (33.5 kD) and an unusual 5' structure of ten dT-nucleotides. Hybridisation of the pTOM 13 cDNA insert to Southern blots of tomato DNA indicates the presence of only a small number of homologous sequences in the tomato genome.

Amino Acid Sequence↗
PubMed1987

An improved immunoblotting procedure for the detection of antibodies against HIV.

Immunoblotting ('Western blotting') is routinely used for detection of antibodies against HIV in the diagnosis of HIV infection. We describe an improved procedure, which does not require virus purification and is easy to control for 'false-positive' results. The technique also does not produce erroneous results due to reactivity of the developing system with residual cellular proteins or viral antigens and does not give high nonspecific background staining. The technique can be applied to the detection of antibodies to HIV in serum, plasma, and blood products.

Acquired Immunodeficiency Syndrome↗
PubMed1987

Strangulation in child abuse: CT diagnosis.

The central nervous system is commonly affected in child abuse. Between April 1985 and July 1986 three infants were identified in whom the primary mode of injury had been strangulation. In each case computed tomography (CT) demonstrated a large cerebral infarction confined to vascular territories associated with small subdural hematomas. There was no history or visible evidence of significant head trauma. Autopsy of one infant confirmed the presence of a hemispheric infarct, thin subdural hematoma, and an area of subintimal hemorrhage in the carotid artery ipsilateral to the infarct. The remaining two patients survived with residual hemiparesis. CT findings of a large cerebral infarction with an associated subdural hematoma in an infant without a history of a significant trauma should suggest the possibility of child abuse and may be the primary manifestation of abuse in some patients.

Asphyxia↗
PubMed1986

Sequencing and identification of a cDNA clone for tomato polygalacturonase.

The 2a isoenzyme of tomato polygalacturonase was purified from ripe fruit and characterised. The N-terminal amino acid sequence of the protein was determined in order to identify polygalacturonase cDNA clones. The nucleotide sequence of a ripening-related cDNA (pTOM 6) was determined and found to encode the N-terminal sequence of mature polygalacturonase 2a. The complete open reading frame encodes a polypeptide of molecular weight 50,051, including a putative pre-sequence of 71 amino acids.

Amino Acid Sequence↗
PubMed1986

The effect of primary immunization and concanavalin A on the production of monoclonal natural antibodies.

Hybridomas derived from mice sham-immunized with saline were found to secrete 'natural' antibodies with a wide range of specificities. A high response to bovine serum albumin (BSA) and in particular BSA conjugated with oxazolone was observed routinely. The oxazolone-BSA response was probably directed toward antigenic sites exposed as a result of the coupling procedure; only 2% of the oxazolone-BSA-binding supernatants also bound to oxazolone-ovalbumin. An unexpected cross-reactivity was seen between the oxazolone-BSA-binding supernatants and an 18-amino-acid peptide that forms part of the VP1 capsid protein of poliovirus serotype 3. Some supernatants were also found to react with all proteins tested, including the synthetic poliovirus peptide; this reactivity was maintained following cloning. Primary immunization resulting in the generation of antibodies to the injected antigen nevertheless had no effect on the repertoire of 'natural' antibodies produced. Injection of the T-cell mitogen concanavalin A increased the frequency of 'natural' antibodies. This effect was enhanced when ConA was injected together with antigen.

Animals↗
PubMed1986

Intracranial arterial aneurysms in childhood: more recent considerations.

Nineteen children with congenital, mycotic, traumatic and tumoral arterial aneurysms were studied neuroradiologically. The important role of computed tomography (CT) was shown in two traumatic aneurysm cases where bleeding was clinically inapparent. Among the unique cases described was a boy with a pituitary tumor in whom an aneurysm was discovered incidentally; coexistence of these lesions in childhood has not been documented previously. Nor has a tumoral aneurysm been mentioned (the case reported had a surrounding primary anaplastic sarcoma). Rare cases included a cavernous carotid mycotic aneurysm and infants with hemorrhage from congenital distal middle cerebral artery aneurysms. Marked cellular responses within the aneurysm walls, believed to be a reaction to hemorrhage, were noted in both infants.

Adolescent↗
PubMed1985

Computed tomography in the diagnosis of intracranial neoplasms in children.

The authors discuss their original observations using computed tomography (CT) in the diagnosis of posterior fossa neoplasms in children. The subject of CT diagnosis of childhood supratentorial tumors is also reviewed. However, despite the documented value of CT, the authors believe that magnetic resonance imaging (MRI) will eventually offer certain advantages that will make MRI the primary imaging modality for intracranial neoplasms in children.

Astrocytoma↗
PubMed1985

The wheat chloroplast gene for CF(0) subunit I of ATP synthase contains a large intron.

The gene for CF(0) subunit I of ATP synthase has been located in wheat chloroplast DNA, between the genes for CF(0) subunit III and alpha subunit of CF(1). Nucleotide sequencing and analysis of RNA-DNA hybrids indicated that the gene is interrupted by an 823-bp intron which has boundaries similar to those previously described for the introns in protein-coding chloroplast genes of Euglena gracilis. The deduced amino acid sequence of CF(0) subunit I indicates a polypeptide of 183 amino acid residues. However, N-terminal amino acid sequencing of the mature spinach CF(0) subunit I suggests that the protein is synthesised with a N-terminal extension of 17 amino acid residues and is processed to give a protein of mol. wt. 19 001 of 166 amino acids residues. The mature CF(0) subunit I shows similarities in primary and predicted secondary structure to F(0) subunit b of Escherichia coli ATP synthase. A major transcript of 3.3 kb containing sequences from the genes for CF(0) subunit III, subunit I and CF(1) subunit alpha has been observed by RNA-DNA hybridisation.

Journal Article↗
PubMed1985

The cerebellopontine angle and internal auditory canal: neurovascular anatomy on gas CT cisternograms.

We reviewed 103 normal gas CT cisternograms to delineate the appearance of normal neurovascular structures in the cerebellopontine angle (CPA) and internal auditory canal (IAC). Cranial nerves VII and VIII were identified in the CPA in 97% of cases, either separately (53%) or as a bundle (44%). Intracanalicular branches of the VIIIth cranial nerve were identified in 20% of cases, and cranial nerve V was visualized in the CPA in 14%. The characteristic vascular loop, usually the anterior inferior cerebellar artery, was visible in 35% of cases, and, in 22% of visualized cases, was in an intracanalicular location. The internal auditory artery was questionably visualized in one case. In 10% of cases, greater than 66% of the IAC was occupied by the neurovascular bundle. Familiarity with the normal anatomy and variants seen on gas CT cisternograms is necessary to prevent false-positive interpretations.

Cerebellopontine Angle↗