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Biomedical subjects

N Jones

Publications and source records attributed to N Jones.

At least 19 recordsLinked to original sources
PubMed1992

A new method for the isolation of recombinant baculovirus.

An improved method for the isolation of baculovirus recombinants is described. The method involves the replication and maintenance of the baculovirus genome in the yeast Saccharomyces cerevisiae which was accomplished by the isolation of a baculovirus recombinant containing yeast ARS and CEN sequences ensuring stable replication in yeast and a URA3 selectable marker. The viral DNA maintained its ability to replicate in insect cells. An efficient and rapid selection system was set up, to isolate viral recombinants in yeast; DNA from selected yeast colonies was transfected into insect cells to obtain recombinant virus. We demonstrate the utility of this system by isolating recombinant viruses that express two different members of the CREB/ATF family of transcription factors.

Animals↗
PubMed1992

Assessment of assays for the serodiagnosis of Venezuelan equine encephalitis.

An enzyme-linked immunosorbent assay (ELISA), an immunofluorescence assay (IFA), a plaque-reduction neutralization (PRN) assay and an immunoblot assay, all by means of an antigen prepared from the attenuated Venezuelan equine encephalitis (VEE) vaccine strain of virus, were compared with the conventional haemagglutination-inhibition (HAI) assay for the serodiagnosis of VEE. The HAI assay, which includes the use of wild type virus antigen, was less sensitive than the other assays when known-positive samples of serum from an epidemic of VEE were tested. The superior sensitivity of the IgG ELISA was confirmed by assaying both VEE epidemic samples and a bank of samples from VEE vaccinees. Samples with antibody specific for other Alphaviruses, however, cross reacted weakly in this assay. The PRN, immunoblot and HAI assays, although less sensitive than the ELISA, proved more specific. Experimental infection of guinea-pigs demonstrated the value of the IgM ELISA in the early detection of VEE virus infection. Immunoglobulin M was first found at 4 days post-inoculation (p.i.) during the viraemic phase of infection. Immunoglobulin G was detected by ELISA, PRN assay and IFA at 6 days p.i. Immunoblot and HAI assays, however, did not give positive results until 10 days p.i. The results support the diagnostic use of ELISA for detecting VEE virus-specific IgM and IgG, and the use of the specific PRN assay for confirming the diagnosis.

Animals↗
PubMed1992

New acuity test for toddlers.

Preferential looking is the technique of choice for measuring visual acuity in infants and young children. Most workers agree that the toddler age group, 1 to 3 years, is the most difficult to test. This is because of their short attention span and restlessness, but mostly because they find the grating target used in the test, frankly boring. The concept of the vanishing optotype chart offers alternative test targets, while utilizing the technique of preferential looking. We have designed a test which comprises a familiar shape (house, car etc.) on the upper or lower part of a neutral grey card. The shape is computer generated, and designed to fade completely when beyond the resolution limit. Acuity is determined by the width of the white lines making up the shape. As with conventional preferential looking, the observer notes the child's eye movements to determine the position of the target shape. Although picture naming is not required, the shapes help to maintain the child's interest in the test. The test is quick, and is successful with the toddler age group and older patients with intellectual impairment.

Child, Preschool↗
PubMed1992

Trauma: the leading cause of maternal death.

The records of the Cook County Medical Examiner were reviewed for the period January, 1986, to December, 1989. Ninety-five maternal deaths were identified. The causes of maternal death were categorized as direct maternal, indirect maternal, or nonmaternal. Direct maternal causes of death (18.9%) were the result of complications of pregnancy, labor, delivery, or its management. Indirect maternal causes of death (12.6%) occurred when pre-existing health problems were exacerbated by pregnancy. All other maternal deaths were the result of nonmaternal causes. Nonmaternal causes of maternal death were further classified as traumatic or nontraumatic. Traumatic maternal deaths (46.3%) were attributed to homicide in 57% and suicide in 9%. The mechanism of injury in traumatic maternal deaths included gunshot wounds (22.7%), motor vehicle crashes (20.5%), stab wounds (13.6%), strangulation (13.6%), blunt head injuries (9.1%), burns (6.8%), falls (4.5%), toxic exposure (4.5%), drowning (2.3%), and iatrogenic injury (2.3%). Trauma was therefore the leading cause of maternal death, accounting for 46.3% of deaths in this series.

Adolescent↗
PubMed1991

A monoclonal antibody (OT145) specific for the T cell antigen receptor V beta 6.7a allele detects an epitope related to a proposed superantigen-binding site.

A mAb, OT145, recognizes a TCR allotype encoded by one of two alleles of the V beta 6.7 gene. The peptide products of the two V beta 6.7 alleles differ because of nonconservative amino acid substitutions at positions 38 and 72. V beta 6.7a encodes ser38 and gly72, whereas V beta 6.7b encodes arg38 and glu72. We show here that the binding of mAb OT145 ot the beta-chain of TCR is lost when residue 72 of V beta 6.7a is mutated from gly to glu. The binding of OT145 is not affected by mutation of residue 38 from ser to arg. Thus, OT145 recognizes an epitope related to position 72. Residue 72 of the beta-chain of the TCR is located at a putative superantigen-binding site.

Alleles↗
PubMed1991

Effects on quality of life with comprehensive rehabilitation after acute myocardial infarction.

This investigation was designed to determine the impact of a brief period of cardiac rehabilitation, initiated within 6 weeks of acute myocardial infarction (AMI), on both disease-specific and generic health-related quality of life, exercise tolerance and return to work after AMI. With a stratified, parallel group design, 201 low-risk patients with evidence of depression or anxiety, or both, after AMI, were randomized to either an 8-week program of exercise conditioning and behavioral counseling or to conventional care. Although the differences were small, significantly greater improvement was seen in rehabilitation group patients at 8 weeks in the emotions dimension of a new disease-specific, health-related Quality of Life Questionnaire, in their state of anxiety and in exercise tolerance. All measures of health-related quality of life in both groups improved significantly over the 12-month follow-up period. However, the 95% confidence intervals around differences between groups at the 12-month follow-up effectively excluded sustained, clinically important benefits of rehabilitation in disease-specific (limitations, -2.70, 1.40; emotions, -4.86, 1.10, where negative values favor conventional care and positive values favor rehabilitation) and generic health-related quality of life (time trade-off, -0.062, 0.052; quality of well-being, -0.042, 0.035) or in exercise tolerance (-38.5, 52.1 kpm/min); also, return to work was similar in the 2 groups (relative risk, 0.93; confidence interval, 0.71, 1.64).(ABSTRACT TRUNCATED AT 250 WORDS)

Anxiety↗
PubMed1991

Independent transformation activity by adenovirus-5 E1A-conserved regions 1 or 2 mutants.

Two conserved regions (CR1 and CR2) on the adenovirus E1A proteins have previously been shown to be required for cooperation with the ras oncogene in the transformation of primary rodent cells. Sequences within these regions are essential for the ability of E1A to associate with the 105K product of the retinoblastoma susceptibility gene, p105-RB, as well as with other cellular proteins, including a 107K (p107) and a 300K (p300) species. In this paper, we show that CR1 mutants deficient in p300 binding and CR2 mutants with lost or reduced binding of p105-RB and/or p107 have a low, but not abolished focus formation activity. In contrast, CR1/CR2 double mutants were deficient in focus formation, suggesting that the transformation activities displayed by the single CR1 or CR2 mutants were due to an independent transformation activity by both CR1 and CR2. No strict correlation between p105-RB binding and E1A-mediated transformation was observed. The E1A enhancer repression function was found to correlate with the binding of p300 but not with E1A-mediated transformation. Complex formation between E1A and p107, similar to the p105-RB binding, required sequences within both CR1 and CR2. The CR2 sequences required for binding of p107K or p105-RB were overlapping, but not identical. Finally, a larger segment of CR2 was required for stable complex formation between E1A and phosphorylated forms of p105-RB or p107 compared to corresponding unphosphorylated species.

Adenovirus Early Proteins↗
PubMed1991

Congenital cholesteatoma.

We present a British series of eleven patients with primary cholesteatoma, including one patient with bilateral disease. Eight children presented with a history of hearing loss, while one child had had recurrent otitis media and another had had earache. Operative findings were: in five ears, cholesteatoma confined to the antero-superior segment with intact ossicles, in a further four, cholesteatomas extending throughout the mesotympanum with ossicular erosion in one, and in two ears posterior disease throughout the middle ear and mastoid, which had eroded the ossicles in both cases. The five cases of antero-superior cholesteatoma lend most support to Michaels' concept of epidermoid formation as a possible source of congenital cholesteatoma. With a greater awareness of the problem and careful examination of the antero-superior quadrant of the tympanic membrane, earlier diagnosis may be possible enabling removal of small intact cholesteatoma sacs and preserving the structures of the middle ear and therefore the hearing. A screening programme for infants included as part of their routine examination which would be undertaken by examiners who are trained to be more aware of the problem and skilled at otoscopy, would help in the earlier detection of such cases as is shown by reports from the U.S.A.

Child↗
PubMed1991

Immunochemical studies on the differential binding properties of two monoclonal antibodies reacting with Tn red cells.

Two monoclonal antibodies (MoAbs), BRIC 66 (IgM) and BRIC 111 (IgG1), were produced by immunizing mice with ovarian cyst blood group A1 glycoprotein and Tn red cells (RBCs), respectively. Their specificities were determined by inhibitions using Tn sialoglycoproteins (SGPs), mucins (armadillo [ASG] and ovine [OSG] submaxillary glycoproteins), and monosaccharides. BRIC 66 agglutinated both Tn and group A RBCs and reacted immunohistochemically with both the vascular endothelium and tumor cells from a group A adenocarcinoma, BRIC 66 was inhibited by N-acetylgalactosamine (GalNAc), Tn SGPs, and mucins on both hemagglutination inhibition tests and radioimmunoassay. BRIC 111 agglutinated Tn RBCs only, and it specifically stained tumor cells from a group O patient's breast carcinoma and a group A patient's adenocarcinoma. In hemagglutination inhibition tests, BRIC 111 was readily inhibited by Tn SGPs, only partially inhibited by GalNAc, and not inhibited by mucins. In a sensitive radioimmunoassay, BRIC 111 was inhibitable by GalNAc. Tn SGP was 2000-fold more effective as an inhibitor than the mucins (ASG and desialized OSG), which contain a high content of terminal alpha-GalNAc-O-serine (threonine) residues. It is postulated that BRIC 66 is specific for terminal alpha-GalNAc units in carbohydrate chains. The exclusive reaction of BRIC 111 with Tn SGP indicates a combining site larger than GalNAc alpha-1, which probably includes amino acid residues in juxtaposition to GalNAc in Tn SGP. In view of its specific agglutination of Tn RBCs, BRIC 111 is a useful reagent for the examination of polyagglutinable RBCs.

ABO Blood-Group System↗
PubMed1990

Expression of HLA ABC and DR antigens in thyroid neoplasia and correlation with mononuclear leukocyte infiltration.

The rejection of tumor cells by the immune system depends on the production of tumor-associated antigens and the expression of HLA antigens on these cells. We therefore studied the expression of HLA ABC and DR antigens in malignant and benign thyroid disorders and correlated it with the types and extent of mononuclear cell infiltration. In the normal thyroid, HLA ABC expression was weak and focal, while it was diffusely present in benign disorders and in most but not all malignancies. HLA DR antigens, while absent or infrequently expressed in normal thyroid, were strongly but often focally expressed in all cases of autoimmune thyroid disease (AITD), as well as in most cases of malignant tumors and benign epithelium surrounding these tumors, and colloid nodule disease. There was a T cell predominance in all disorders, and the CD4+/CD8+ ratio was greater than 1 in most benign and malignant specimens. There was a direct correlation between the high expression of HLA antigens and dense inflammatory infiltration in AITD but not in most tumor specimens. Lack of such correlation suggests that the expression of HLA antigens is an autonomous event in tumors, independent of cellular infiltrate.

Antibodies, Monoclonal↗
PubMed1990

Reconstruction of the cervical esophagus: free jejunal transfer versus gastric pull-up.

Use of enteric grafts is a popular method for reconstruction of the cervical esophagus and hypopharynx. Free jejunal transfer (FJT) and gastric pull-up (GP) are the most popular methods used. This discussion is a retrospective review of our experience with 50 cases of free jejunal transfer and 15 cases of gastric pull-up. The graft survival rate was 94 percent (47 of 50) for free jejunal transfer and 87 percent (13 of 15) for gastric pull-up. Successful swallowing was achieved in 88 percent (44 of 50) of free jejunal transfers and 87 percent (13 of 15) of gastric pull-ups. Patients with free jejunal transfers were able to swallow and leave the hospital sooner: 10.6 versus 16.0 days and 22.3 versus 29.0 days, respectively. Fistulas occurred in 16 percent (8 of 50) of free jejunal transfers, most of which (6 of 8) healed spontaneously. Fistulas occurred in 20 percent (3 of 15) of gastric pull-ups, only one of which healed spontaneously. Stricture was the most common late complication for free jejunal transfers, 22 percent (11 of 50), whereas reflux was most common in gastric pull-ups, 20 percent (3 of 15). In patients with advanced cancer, extensive esophageal resection into the chest is often required, and gastric pull-up seems to be an easier and more direct form of reconstruction. In limited resection of the hypopharynx and esophagus, especially with proximal lesions, free jejunal transfer is simpler and avoids mediastinal dissection. This concept as well as other advantages and disadvantages of both techniques will be discussed.

Adolescent↗
PubMed1990

The reliability of palpation in the assessment of tumours.

There is now a joint UICC-AJC classification for cervical lymph nodes based mainly on the size of the nodes. There is a recognized error in palpation, not only for detecting the presence of tumour but also its size. This study used an animal tumour model system to compare the ability of 6 independent observers of varying experience to detect and stage superficially transplanted growths. A preclinical medical student was as good as a Consultant ENT Surgeon in predicting the presence of tumour but the ability to stage tumours accurately was related to experience. Whilst the most experienced observers accurately estimated the size of tumours less than 2 cm, they were less accurate for larger (greater than 2 cm) tumours which were constantly understaged. This phenomenon may have important clinical implications particularly related to current nodal staging criteria.

Animals↗
PubMed1990

The Edinburgh-ORLAU prosthetic system to provide reciprocal locomotion in children and adults with complete transverse lower limb deficiency.

A novel prosthetic system to provide reciprocal locomotion in children and adults with complete transverse lower limb deficiency is described. This is based on the hip joints from the ORLAU ParaWalker, a system with a proven record of success in the orthotic management of paraplegic patients. The fitting of the prototype system to an eight year old girl is described. This experience shows that the orthotic principles of the ParaWalker, which provides reciprocal locomotion for the paraplegic, is equally applicable to the prosthetic situation. Developments are therefore continuing to improve the design and to enable further fittings.

Artificial Limbs↗