Search PubMed⌕ Search

Biomedical subjects

J Bell

Publications and source records attributed to J Bell.

At least 289 records · Page 16Linked to original sources
PubMed1989

A mouse analogue of the human carcinoembryonic antigen.

Functional human carcinoembryonic antigen (CEA)-like genes have been shown to be present in the mouse. Southern analyses of murine DNA using both human and murine CEA complementary DNA probes have revealed the presence of multiple CEA-like genes, while analyses of RNA from different mouse tissues showed CEA-like transcripts in adult colon and liver. Furthermore, a CEA-like protein, immunoprecipitable with a rabbit polyclonal serum raised against human CEA, has been detected in adult murine colon tissue. Several murine CEA complementary DNA clones have been isolated from a murine colon complementary DNA library, and characterization of one such clone demonstrates that both the N-terminal and the internal domains have been conserved between the two species. The existence of a murine counterpart of CEA strengthens the case for an essential function for this human tumor marker and provides an experimentally amenable system for elucidation of its biological properties.

Animals↗
PubMed1989

Differential expression of alpha and pi isoenzymes of glutathione S-transferase in developing human kidney.

Polyclonal antisera to the alpha and pi isoenzymes of glutathione S-transferase have been used in immunohistochemical studies to determine the developmental expression of these isoforms in human kidney. Before 35 weeks of gestation, both isoenzymes were expressed by the collecting tubules and developing nephrons. After this time, expression of the alpha set was restricted to the proximal tubule and that of the pi set to the distal and collecting tubules and the loop of Henle.

Adult↗
PubMed1989

Intravenous injection of [1-14C]arachidonate to examine regional brain lipid metabolism in unanesthetized rats.

We examined the metabolic disposition and brain distribution of an unsaturated fatty acid, [1-14C]arachidonate, between 5 and 240 min following its intravenous bolus injection in unanesthetized adult rats. Injected [1-14C]arachidonate was cleared rapidly from plasma, with less than 10% remaining by 2 min. Total brain radioactivity, 0.2% of the injected dose, was near maximal by 5 min, reached a peak by 15 min, then slowly declined. Radioactivity in brain lipids constituted greater than 82% of the total brain radioactivity at all times. Radioactivity in aqueous-soluble metabolites was greatest at 5 min (13% of total) and declined to 5% by 240 min. Protein pellet-associated radioactivity gradually rose to a peak of 7% by 120 min. Within the lipid fraction, more than 92% of radioactivity was in glycerolipids, with greater than 81% in phospholipids. Radioactivity in inositol phosphoglyceride was maximal at 5 min (47% of phospholipid radioactivity); and declined to 34% by 20 min, whereas radioactivity in choline phosphoglyceride peaked at 15 min (41% of phospholipid radioactivity) and was constant thereafter. In contrast, radioactivity in ethanolamine phosphoglycerides increased from 7 to 17% during the course of the experiment. Quantitative autoradiography of brain sections indicated incorporation of [1-14C]arachidonate into gray-matter regions was 1.5- to threefold that into white-matter regions. The data were analyzed in terms of a model for brain fatty acid uptake from plasma. Estimates of unidirectional transfer constants, k, for [1-14]arachidonate from plasma to brain regions with an intact blood-brain barrier ranged from 0.0005 to 0.0015 ml.sec-1.g-1 and were correlated with those for [9,10-3H]palmitate. The results indicate that brain phospholipid metabolism in awake animals can be examined regionally and quantitatively using intravenous injection of [1-14C]-arachidonate combined with quantitative autoradiography and biochemical analysis.

Animals↗
PubMed1989

Polarized incident light microscopical enhancement of immunogold and immunogold-silver preparations: its role in immunohistology.

Polarized incident light microscopy (PILM) is a recognized method of visualization of bound colloidal gold in cytological immunocytochemical preparations. This study investigates its role in the assessment of histological sections using both indirect immunogold and immunogold-silver staining methods. With dark field or bright field illumination this technique was found to be advantageous and allowed easy detection staining at low magnification and accurate detection of low levels of stain product. We advocate this technique as a valuable microscopical enhancement method for immunogold immunohistology.

Breast↗
PubMed1989

An observation of DNA ploidy, histological grade, and immunoreactivity for tumour-related antigens in primary and metastatic breast carcinoma.

A cohort of 36 cases of advanced breast carcinoma were included in the study. DNA ploidy, histological grade, and immunoreactivity for carcino-embryonic antigen (CEA), carcino-embryonic antigen with normal cross-reacting antigen (CEA/NCA), and to NCRC-11 were assessed in primary breast carcinomas and metastases from the ovary and axillary lymph nodes. Changes in these variables between primary tumours and their metastases were found in 44 per cent of cases for DNA ploidy, 44 per cent of cases for histological grade, 17 per cent of cases for immunoreactivity to NCRC-11, 28 per cent of cases for CEA, and 56 per cent of cases for CEA/NCA immunoreactivity, respectively. Alteration of one factor appeared to be independent of changes in other factors. The development of clones with metastatic potential does not appear to be related to consistent changes in any one of the factors examined and suggests that none of these factors would be of prognostic value in advanced breast carcinoma.

Antibodies, Monoclonal↗
PubMed1989

5-year survival of patients with periaortic nodal metastases in clinical stage IB and IIA cervical carcinoma.

From 1969 to 1981 thirty-six patients with stage IB and IIA cervical carcinoma were identified at pretherapy surgical staging laparotomy with histologically documented metastatic disease to the periaortic lymph nodes. All patients underwent a periaortic node dissection and all patients completed a course of extended-field radiotherapy in a postoperative setting. No major radio-therapeutic complications were encountered. The 5-year actuarial survival rate was 50%, with a median survival time of 29 months. The median time to recurrence was 10 months, while the median duration of survival following a recurrence was 7 months. Seventy-five percent of all recurrences occurred at distant sites. These data demonstrate that survival may be favorably influenced by employing extended-field radiotherapy in those patients with early-clinical-stage cervical cancer and periaortic nodal metastases. The subsequent development of distant metastases after such a treatment regimen emphasizes the need for adjuvant cytotoxic chemotherapy to enhance overall survival.

Carcinoma↗
PubMed1989

The polymerase chain reaction.

The polymerase chain reaction (PCR) is a novel technique that amplifies specific sequences with remarkable efficiency. Repeated cycles of denaturation, primer annealling and extension carried out with the heat stable enzyme, Taq polymerase, leads to exponential increases in the target DNA sequences. The technique has been widely applied in immunology to define HLA polymorphism, T-cell receptor and immunoglobulin diversity, pathogen detection, quantification of lymphokines and lymphoma or leukaemia detection. In addition, it has been very widely applied in all areas of molecular biology and human genetics. Because of its simplicity and sensitivity, PCR represents a major technical development for molecular biologists and will continue to have a great impact on molecular immunology. This review by John Bell describes the basic PCR technique and some variations on it and briefly explores their uses in molecular immunology.

DNA↗
PubMed1989

Pulmonary changes in breast cancer patients treated by three different radiotherapy techniques.

Twenty eight patients with breast cancer were studied by CT, perfusion scans and pulmonary function tests to assess the extent of post-irradiation changes. The patients had been treated by three treatment techniques using either two, three or four fields with different amounts of lung included in the target volume. The most extensive changes were seen in those patients who received treatment to the mediastinum.

Breast Neoplasms↗
PubMed1989

Specificity of polymerase chain amplification reactions for human immunodeficiency virus type 1 DNA sequences.

The polymerase chain amplification reaction (PCR) is a sensitive, specific, and quantitative assay of human immunodeficiency virus type 1 (HIV-1). The assay was performed with polymerases from Escherichia coli or Thermus aquaticus (Taq). A single pair of oligonucleotide primers within the long terminal repeat (LTR) sequences were used to detect HIV-1 sequences in infected cell cultures and fresh tissues of the large majority of infected individuals. The amplified product was a faithful copy of this LTR sequence. Utilization of a subsaturating number of cycles of amplification allowed quantitation of HIV-1 DNA sequences.

Base Sequence↗
PubMed1989

An investigation of NCRC11 immunoreactivity in normal and neoplastic epithelia of the female genital tract and ovary.

NCRC11 is a monoclonal antibody raised against human mammary carcinoma cells. The prognostic value of tumour cell immunoreactivity to NCRC11 in breast cancer has been shown previously. This study describes NCRC11 immunoreactivity in a wide range of normal and neoplastic epithelial types from the female genital tract and ovary. In the tumours examined, a wide range of staining patterns was seen. The implications of these findings are discussed in relation to the potential uses of this antibody in diagnosis and monitoring of gynaecological diseases.

Antibodies, Monoclonal↗
PubMed1989

The prevalence of taurodontism in Down's syndrome.

Taurodontism, a condition in which the pulp chambers of teeth are elongated, was observed in extracted lower molars of 12 out of 33 (36.4%) individuals with Down's syndrome (DS). It is suggested that this high prevalence is associated with a delayed ingrowth and fusion of the epithelial flaps of the developing root sheath and that taurodontism represents one of several characteristic morphological dental features in DS that result from decreased mitotic activity of cells in developing tooth germs.

Adolescent↗
PubMed1989

Segmental dilatation of the small bowel: report of three cases and literature review.

Segmental dilatation of the small bowel is a rare congenital abnormality that occurs mainly in children and produces significant nonspecific symptoms. The authors reviewed 33 cases reported in the literature and present three new cases in which the lesion was demonstrated on radiographs obtained before laparotomy. These cases showed the spectrum of symptoms and characteristic radiologic features of this condition in both plain abdominal radiographs and barium studies. Plain radiographs of the abdomen may show an isolated loop of bowel containing an air-fluid level. The characteristic finding in barium studies of the small bowel is a localized dilatation of the small bowel lumen with afferent and efferent loops. In the absence of a complication or coexistent cause of obstruction, the transit time of contrast medium through the small bowel is not delayed. The radiologic examination is useful in diagnosis, and the condition is cured with surgery.

Abnormalities, Multiple↗
PubMed1989

The psychiatric emergency service holding area: effect on utilization of inpatient resources.

This study compared the rates of hospitalization from two psychiatric emergency services which were similar except that one service had an extended evaluation unit, or holding area, allowing up to 24 hours of evaluation. The rate of hospitalization from the service with the extended evaluation unit was 36%; the rate from the other service was 52%. The difference in admission rates was related to the availability of the extended evaluation unit, which made it possible for many patients to avoid rather than merely postpone admission to the hospital. Clinical determinants of admission and of successful treatment in the unit were also reviewed.

Adolescent↗
PubMed1989

Studies on copper-zinc superoxide dismutase expression in developing human liver and kidney.

CuZn superoxide dismutase levels were found to be high in developing human kidney and liver compared to some other tissues including lung. In kidney, the enzyme was expressed in proximal and distal tubules, loop of Henle and collecting tubules and after 35 weeks of gestation it appeared to be distributed basally in proximal cells and luminally in distal cells. Glomerular structures were generally negative. CuZn superoxide dismutase was widely expressed in developing liver, with hepatocytes and bile duct epithelium demonstrating positivity. The low level of expression of CuZn superoxide dismutase in the glomerulus compared with the tubules was not expected since intrinsic glomerular cells demonstrate greater production of reactive oxygen species in response to some stimuli than do tubular cells. Expression of this enzyme may be determined by the need to generate hydrogen peroxide.

Cytosol↗
PubMed1989

Acromegaly in an infant.

Serial hormonal studies were carried out in a girl with a growth hormone-secreting pituitary adenoma and hyperprolactinemia diagnosed at 21 months of age, the youngest verified case of acromegaly. The child had progressive macrocephaly, noted at 6 months of age, which preceded the rapid acceleration of linear growth by nearly 1 year. At 21 months of age, the girl's head circumference measured 55 cm (+5.5 SD) and her height was 97.6 cm (+4.4 SD). Preoperative serum growth hormone level was 135 ng/mL, somatomedin C was 1,540 ng/mL (normal for bone age 18 to 97 ng/mL), and prolactin was 370 ng/mL (normal less than 20 ng/mL). Following total resection of a large adenoma, immunohistochemical staining of the tumor showed growth hormone but not prolactin. With longitudinal monitoring of the child for 2 years postoperatively, persistently low growth hormone levels were demonstrated and normal growth velocity (6 cm/yr). Peak serum growth hormone levels ranged from 2.8 to 4.1 ng/mL after stimulation tests with insulin, arginine, and L-dopa. Maximum sleep-entrained growth hormone level was 3.4 ng/mL. At the same time, serum somatomedin C levels measured serially were normal (29 to 111 ng/mL), whereas simultaneous prolactin levels were moderately increased (30 to 147 ng/mL). The data support the hypothesis that hyperprolactinemia may have contributed to stimulating somatomedin C and sustaining the normal growth rate in this child.

Acromegaly↗