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Biomedical subjects

I Gordon

Publications and source records attributed to I Gordon.

At least 253 records · Page 14Linked to original sources
PubMed1982

Investigating the small lung: which imaging procedure?

Ventilation and perfusion radionuclide lung scans, using krypton 81m and technetium-99m macroaggregates, were performed together with a variety of other imaging procedures in 18 children aged between 1 week and 13 years in whom radiology had shown a small lung. Radionuclide scans provided an assessment of regional ventilation and perfusion unobtainable by other means, and 4 main categories of disturbed function could be seen in the radiological small lung--namely, absence of ventilation and perfusion, absent perfusion with preserved ventilation, generalised or segmental decreases in ventilation, and perfusion and segmental perfusion defects in areas of decreased ventilation. The clinical history and other imaging procedures, including fluoroscopy and penetrated mediastinal views, enabled a firm diagnosis to be made in each of these 18 patients. In 3 main pulmonary arteries were absent, 2 had lung aplasia, 2 had lobar aplasia, 9 had varying degrees of pulmonary hypoplasia (two with additional sequestrated segments), 1 had lobar emphysema, and 1 had post-infective lung mal-development (MacLeod's syndrome).

Child↗
PubMed1981

Pneumatocoeles following Haemophilus influenzae pneumonia.

Two children are reported who developed lung radiolucencies identical to staphylococcal pneumatocoeles after haemophilus influenzae pneumonia. Recognition that such translucencies can occur after various bacterial pneumonias is important. The radiographic appearances can be confused with congenital lung cysts, which could result in unnecessary surgery. There has been a recent increased incidence of reports of H. influenzae pneumonia in children, with lobar involvement predominating. Thus H. influenzae must be considered a significant cause of lobar pneumonia and the presence of pneumatocoeles does not preclude the diagnosis.

Child, Preschool↗
PubMed1981

Studies on the toxicity and binding kinetics of abrin in normal and Epstein Barr virus-transformed lymphocyte culture-I: experimental results - 3.

The effects of treatment with varying doses of abrin, a D-galactose binding lectin, on DNA and protein synthesis of normal and Epstein Barr virus-transformed lymphocytes have been investigated. Using data on EBV-transformed lymphocyte cell density as a function of time and dose of abrin, one can demonstrate that the mean number of sites bound/EBV-lymphocyte needed to exert a biological influence upon the cell DNA synthesis lies between 59,264 and 370,000 sites/cell. Using a simple packing model, one can demonstrate that a theoretical estimate places the number of binding sites between 57,600 and 360,000 sites/cells.

Abrin↗
PubMed1981

Clinical applications of radionuclide lung scanning in infants and children.

Krypton 81m ventilation and technetium 99m perfusion lung scans in anterior, posterior and oblique views in 86 children (age range 14 days to 15 years) with various paediatric problems were obtained. On reviewing these studies we found four main areas of clinical usefulness. (a) Establishing the diagnosis; in a relatively small number of patients the lung scan was essential for either establishing the exact diagnosis or directing attention to the abnormal area. (b) Refuting a diagnosis: the two main groups in this category include possible bronchiectasis and inhaled foreign body. (c) Establishing the extent of the disease; radionuclide studies enable one to assess and follow up the extent of the disease in children with lower respiratory problems; a lung scan may obviate the need for bronchography in bronchiectatics failing to respond to medical treatment and for whom surgery is being considered. Repeat studies are useful in following the natural history or the response to treatment of various lung conditions. (d) Assessing the success of surgical procedures on the heart and on abnormal pulmonary arteries. We indicate that 81Krm ventilation/99Tcm perfusion scanning are particularly useful in small children in whom tests of overall pulmonary function cannot be carried out because of lact of co-operation.

Adolescent↗
PubMed1981

On the dynamics of abrin binding to receptor sites in normal and Epstein Barr Virus transformed lymphocyte cell cultures.

The effects of treatment with varying doses of abrin, a D-galactose binding lectin, on DNA an protein synthesis of normal and Epstein Barr Virus transformed lymphocytes has been investigated. Activation, stimulation, and relative toxicity factor indices are studied, as well as possible relationships between DNA and protein synthesis rates, as measured by simultaneous tritiated thymidine (3H-TdR) and 14C-leucine uptake. Studies of the two new indices, the metabolic self and cross coupling indices lead to the prediction that there are three morphologically distinct subpopulations of EBV-transformed lymphocytes with different abrin receptor site concentrations. This prediction is supported by SEM morphological differences. Using data on EBV-transformed lymphocyte cell density as a function of time and dose of abrin, one can demonstrate that the mean number of receptors bound-EBV-lymphocyte needed to exert a biological influence lies in the interval 59,264 receptors/cell to 370.040 receptors/cell. Using a simple packing model, one can demonstrate that a theoretical estimate places the number of binding sites between 57,600 receptors/cell and 360,000 receptors/cell.

Abrin↗
PubMed1980

Inhibition of interferon production and antiviral action in mouse cells by 4,5',8-trimethylpsoralen activated with near ultraviolet light. Brief report.

The DNA of mammalian cells treated with 4,5',8-trimethylpsoralen (Trioxsalen) is crosslinked (preventing transcription) only after photoactivation with near ultraviolet light. Suppression of gene action in cocultivated or fused cultures, including both induction and antiviral action of fibroblast interferon, can consequently be limited to pretreated cells, an advantage over actinomycin treatment.

Cell Line↗
PubMed1980

Kinetics of decay in the expression of interferon-dependent mRNAs responsible for resistance to virus.

We used 5,6-dichloro-beta D-ribofuranosyl-benzimidazole (DRB), a selective and reversible inhibitor of mRNA production, to investigate the regulation of the pathway leading to resistance to viruses in cells treated with interferon (IF). DRB allows initiation of transcription but promotes premature termination of the nucleotide chains, so that it abolishes interferon-dependent protection against viruses. When the DRB is removed, synthesis of complete mRNAs can resume. Mouse L-929 cells were exposed to 100 microM DRB before and during a 1-hr pulse of IF followed by treatment with antibody to IF to prevent cell-to-cell spread of IF after that time. At different intervals thereafter the cells were washed and the DRB was replaced by medium; after further incubation, the cells were infected with vesicular stomatitis virus. Resistance to virus was inversely proportional to the duration of the block imposed by DRB. When the DRB was removed soon after the IF pulse, substantial protection from virus ensued, but none developed when removal of the DRB was deferred for 5-6 hr. Cells exposed to DRB for 5 hr, then pulsed with IF for 1 hr, still mounted a strong antiviral response. The data show that the ability of cells to resist viral infection decays within 5-6 hr after treatment with IF. Whether the decay is due to shutoff of transcription of mRNAs, or to their destruction or degradation, or whether regulation takes place at one or more subsequent steps in the antiviral pathway, remains to be determined.

Animals↗
PubMed1979

Early and late results of surgical correction of pulmonary artery sling.

Since 1976, we have operated on 4 children with pulmonary vascular sling. They were 5, 12, 19, and 54 months old. All patients were seen initially with severe stridor. Diagnosis was made by barium swallow in all 4. Each child was operated on through a left thoracotomy; the left pulmonary artery was dissected deep between the trachea and esophagus. Systemic heparinization and microsurgical techniques were used. All patients improved after operation. Radioisotope pulmonary ventilation/perfusion scans were performed 9, 9, 14, and 21 months after operation. Decreased ventilation was noted in the right upper lobe of one scan; the other three ventilation scans were normal. Perfusion scans showed good patency of both pulmonary arteries in all 4 patients. It is concluded that pulmonary vascular slings should be treated surgically as soon as diagnosed. Delayed operation can lead to severe tracheomalacia, as demonstrated in our 54-month-old patient.

Child, Preschool↗
PubMed1977

Correlation of e antigen, DNA polymerase activity, and Dane particles in chronic benign and chronic active type B hepatitis infections.

The e determinant of hepatitis B surface antigen (HBS Ag) was found in 23 of 42 patients with chronic hepatitis B virus (HBV) infection. Presence of e antigen was associated with increases in DNA polymerase activity and in the number of circulating Dane particles. In the group with detectable e antigen, the average DNA polymerase activity was 367+/-78 counts per minute (cpm; mean+/-standard error [SE]), and the average number of Dane particles counted in electron micrographs was 4.4% of the total HBS Ag. In contrast, e antigen-negative patients had an average DNA polymerase activity of 40+/-6.9 cpm (P less than 0.1) and an average Dane particle count equal to 0.6% of the HBS Ag. The e antigen was detected in 68% of patients who were HBS Ag carriers or had persistent viral hepatitis and 40% of those with chronic active type B hepatitis. Thus, the presence of e antigen correlated with both the chronicity and presence of infectious HBV. However, it did not correlate with the type or severity of liver disease after HBV infection, since e antigen was present in both chronic benign and chronic aggressive hepatitis B infections.

Adult↗