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Biomedical subjects

A Ferguson

Publications and source records attributed to A Ferguson.

At least 127 records · Page 7Linked to original sources
PubMed1993

Mosaic disease induced by turnip yellow mosaic Tymovirus.

Mosaic disease is one of the most common consequences of infection of plants by viruses. Most such mosaics include islands of dark green tissue, which are normal in appearance, contain little or no virus and are resistant to superinfection at least for a period of weeks. The mosaic pattern that develops in successive expanded leaves of larger plants is variable and unpredictable. Therefore it has not been possible to investigate the early events in leaf primordia that lead to the formation of dark green tissue. Here we describe an experimental system which should allow the application of molecular techniques to the study of the nature of dark green tissue.

Brassica↗
PubMed1993

Is there cross-refractoriness between phospholipase A2 and the calcium ionophore A23187 in the stimulation of uterine prostaglandin production?

Phospholipase (PL) A2 increased the outputs of prostaglandin (PG) F2 alpha, PGE2 and 6-keto-PGF1 alpha from the mid-cycle guinea-pig uterus, but repeating the PLA2 treatment 1 h later failed to increase uterine PG output. Similarly, A23187 increased PG output from the mid-cycle guinea-pig uterus, but repeating the A23187 treatment 1 h later produced a very much smaller stimulatory effect. Thus the guinea-pig uterus showed complete refractoriness to PLA2 and partial refractoriness to A23187, as regards the stimulation of uterine PG production, when the uterus is treated with the same compound after an interval of 1 h. However, when the mid-cycle guinea-pig uterus was treated with PLA2 1 h after being treated with A23187, or was treated with A23187 1 h after being treated with PLA2, the second compound produced a normal stimulation of PG output and was not affected, therefore, by treatment with the first compound. Consequently, there is no cross-refractoriness between PLA2 and A23187 as regards their stimulatory effects on PG production by the guinea-pig uterus.

Animals↗
PubMed1993

Breast-feeding of very low birth weight infants.

Twenty very low birth weight infants (birth weight < 1500 gm) were assessed to compare the clinical effects of breast and bottle feedings. The infants started breast-feeding during the same week that they started bottle feedings. Five breast-feedings and five bottle feedings for each infant were observed. Axillary temperature and weight before and after feedings were measured, and oxygen saturation, respiratory rate, and heart rate were monitored and recorded every 2 minutes during the feeding periods. The results showed no difference in oxygen saturation during breast-feeding (p = 0.056) but a lower incidence of oxygen desaturation (< 90%) (21% vs 38% in breast-feeding vs bottle feeding, respectively; p < 0.025). Infants with bronchopulmonary dysplasia had higher oxygen saturation during breast-feeding than during bottle feeding (p < 0.025), but weight gain during breast-feeding sessions was less (median, no gain vs 31 gm, p < 0.001). We conclude that (1) very low birth weight infants can tolerate both breast and bottle feedings at the same postnatal age; (2) very low birth weight infants are less likely to have oxygen desaturation to less than 90% during breast-feeding; and (3) weight gain is less during breast-feeding, probably because of lower intake, and may require more lactation counseling or supplementation of the feedings.

Body Weight↗
PubMed1993

Disseminated metastatic cutaneous Crohn's disease.

Metastatic cutaneous Crohn's disease, in which noncaseating granulomatous infiltration of the skin occurs at sites separated from the gastrointestinal tract by normal tissue, is the least common dermatological manifestation of Crohn's disease. We report the case of an 18-year-old man who developed very widespread metastatic cutaneous Crohn's disease 2 years after he had first developed mild oral and anal lesions. His gastrointestinal symptoms had been satisfactorily controlled for 18 months with sulphasalazine alone prior to his developing skin lesions. The cutaneous lesions responded rapidly to oral prednisolone which was tailed off over 5 months and then withdrawn. He relapsed 6 months later and now requires a low dose of oral prednisolone to control the skin lesions. The only complication of this therapy has been exacerbation of mild acne vulgaris.

Adolescent↗
PubMed1993

Spectrum of expression of intestinal cellular immunity: proposal for a change in diagnostic criteria of celiac disease.

The clinical heterogeneity of celiac disease is well recognized, with great variability in malabsorption and in gastrointestinal symptoms of patients with active celiac disease, and the fairly common occurrence of silent celiac disease (ie, an apparently healthy individual with a flat small bowel mucosa). Research in experimental animals has shown that expression of cell-mediated immunity in the gut mucosa occurs in a spectrum of pathologies ranging from minimal enteropathy with a high count of intra-epithelial lymphocytes to the celiac-like lesion with short villi and long crypts. A similar range of pathology is seen in celiac patients in some circumstances, with low grade enteropathy occurring in the early stages of gluten challenge, in patients taking a low gluten diet, and also in some patients with dermatitis herpetiformis. In so-called latent celiac disease, sophisticated immunologic studies may reveal a high intra-epithelial lymphocyte count, an increased gamma delta intra-epithelial lymphocyte count, and a celiac-like intestinal antibody abnormality with overexpression of mucosal IgM responses. If further work confirms that one or more of these features may be the only manifestation of gluten-sensitive disease in some newly presenting patients, the current definition of celiac disease (a flat mucosa, gluten-sensitive) will need to be revised.

Biopsy↗
PubMed1992

Haemoglobin in gut lavage fluid as a measure of gastrointestinal blood loss.

To detect and measure occult gastrointestinal bleeding, we have measured haemoglobin concentrations (by HemoQuant) in the clear fluid obtained after whole-gut lavage. In subjects with healthy gastrointestinal tracts, lavage-fluid haemoglobin concentrations were 0.5-5.1 mg/L, equivalent to daily blood loss of 0.1-1.1 mL. High concentrations were found for patients with colorectal cancer, severe diverticular disease, and rectal varices, in seven of sixteen patients with active inflammatory bowel disease, and in four patients with iron-deficiency anaemia thought to be due to gastrointestinal bleeding. In these four patients, estimated blood loss ranged from 2.6-24.5 mL per day. This method could have various research and clinical applications.

Barium Sulfate↗
PubMed1992

Definitions and diagnosis of food intolerance and food allergy: consensus and controversy.

This article describes the terms used for the various syndromes and diseases associated with reactions to foods; it outlines the principal types of food intolerance encountered in children, with particular emphasis on those caused by immune-mediated reactions of immediate hypersensitivity. Terms defined include food intolerance or food sensitivity; food allergy or food hypersensitivity; psychologically based food reactions (food aversions); and psychosocial and neurologic dysfunction. The spectrum of food sensitivity is considerable, and diagnosis is generally based on the monitoring of effects of exclusion diets and provocation tests, after appropriate objective measures are first selected. In children, manifestations of IgE-mediated food allergy (often in association with other immune mechanisms) include self-limiting and immediate reactions (e.g., urticaria, wheeze) and chronic diseases (food-sensitive enteropathies, eczema). Controversial and unresolved issues exist with some other conditions, including eosinophilic gastroenteritis, occult gastrointestinal bleeding, protein-losing enteropathy, and attention deficit disorder with hyperactivity. New methods for clinical investigation of gastrointestinal tract function and intestinal immune reactions are required to assess the relevance of foods in these conditions.

Antigen-Antibody Reactions↗
PubMed1992

Three novel mutations in the cystic fibrosis gene detected by chemical cleavage: analysis of variant splicing and a nonsense mutation.

We have used the chemical cleavage mismatch technique to screen for mutations in the cystic fibrosis gene. Analysis of exons 10 and 11 in the first nucleotide binding fold led to the detection of several described mutations and two novel mutations, V520F and C524X. V520F results from a G-->T nucleotide substitution changing a valine to a phenylalanine residue, while C524X (a nonsense mutation), results from a C-->A transversion. A third novel mutation, Q1291H (G-->C), at the last nucleotide of exon 20, would substitute a histidine residue for glutamine. Further study, involving RNA based PCR, revealed that Q1291H was also a splice mutation. Both correctly and aberrantly spliced mRNAs are produced from the Q1291H allele. The incorrectly spliced product results from the use of a nearby cryptic splice site 29 bases into the adjacent intron.

Adult↗
PubMed1992

Systemic and mucosal antibodies to Klebsiella in patients with ankylosing spondylitis and Crohn's disease.

Whole gut lavage fluid is a useful source of material for the study of intestinal immunity and inflammation in humans. Systemic and mucosal antibodies to Klebsiella pneumoniae were measured by enzyme linked immunosorbent assay (ELISA) in serum samples and whole gut lavage fluid from 14 patients with ankylosing spondylitis, 14 with Crohn's disease, and 16 immunologically normal controls. As the concentration of IgG in whole gut lavage fluid reflects disease activity in Crohn's disease, this approach was used to detect intestinal inflammation in patients with ankylosing spondylitis who also had disease activity and use of non-steroidal anti-inflammatory drugs (NSAIDs) recorded. Small intestinal permeability to cellobiose and mannitol was also studied. In serum samples, levels of IgA antibody to klebsiella were high in patients with Crohn's disease and in patients with active ankylosing spondylitis, and were significantly correlated with the erythrocyte sedimentation rate in patients with ankylosing spondylitis. Levels of IgG antibody to klebsiella were also high in patients with Crohn's disease. Studies of whole gut lavage fluid showed similar levels of IgA antibody to klebsiella in the three study groups, but levels of whole gut lavage fluid IgM and IgG antibodies to klebsiella were high in patients with Crohn's disease. Levels of IgG in whole gut lavage fluid were high in patients with Crohn's disease but in only one patient with ankylosing spondylitis, though the cellobiose/mannitol permeability ratio was abnormal in eight of 13 patients with ankylosing spondylitis. It is concluded that high levels of serum IgA antibody to klebsiella are not specific to ankylosing spondylitis, and that there is no evidence of an abnormal intestinal IgA antibody response to klebsiella in patients with ankylosing spondylitis.

Adult↗
PubMed1992

Immunosenescence and mucosal immunity: significant effects of old age on secretory IgA concentrations and intraepithelial lymphocyte counts.

Concentrations of immunoglobulins (Ig) and levels of isotype specific antibodies to three dietary antigens in serum, pure parotid saliva, and in intestinal secretions obtained by whole gut lavage from groups of healthy elderly subjects (aged greater than 70 years) and of younger adult controls (aged 25-50 years) were measured. In addition, counts of lamina propria and intra-epithelial lymphoid cells were performed in histologically normal jejunal biopsy specimens from elderly and younger subjects. Elderly subjects had significantly higher concentrations of serum and salivary IgA and of salivary IgM (both, p less than 0.01), and of salivary IgA antibodies than did the younger subjects, but the amount of immunoglobulin and antibody in whole gut lavage fluid was similar in the two age groups. Jejunal biopsy specimen cell counts showed higher IgA plasma cell counts and lower intraepithelial lymphocyte counts in the elderly group (p less than 0.01), with similar counts of IgM and IgG plasma cells, eosinophils, and mast cells in the two groups. There is evidence of significant effects of old age on the mucosal immune system.

Adult↗
PubMed1992

Mechanisms of Sertoli cell insulin-like growth factor (IGF)-binding protein-3 regulation by IGF-I and adenosine 3',5'-monophosphate.

FSH, which stimulates cAMP in the Sertoli cell, markedly lowers the concentration of insulin-like growth factor-binding protein-3 (IGFBP-3) in Sertoli cell-conditioned medium; in contrast, insulin-like growth factor-I (IGF-I) increases BP-3 expression. In this study, the mechanisms controlling the contrasting effects of cAMP and IGF-I were investigated. The abundance of BP-3 mRNA was dramatically lowered by (Bu)2cAMP, but was unaffected by IGF-I. Analyzed by ligand blot of conditioned medium, coincubation of (Bu)2cAMP and IGF-I largely eliminated the increase observed with IGF-I alone. Based on the following evidence, the effect of IGF-I appeared to be solely related to the capacity of IGF-I to interact directly with BP-3. 1) Insulin at micromolar concentrations failed to increase BP-3 abundance despite documentation by affinity cross-linking that insulin displaced [125I]IGF-I from the IGF-I receptor. 2) A synthetic IGF-I analog, [Leu24,1-62]IGF-I, which has reduced binding affinity for rat IGF-I receptor but displays high affinity for rat Sertoli cell-conditioned medium BPs, increased BP-3 abundance. 3) A synthetic IGF-I analog, B-chain mutant, which has reduced affinity for rat Sertoli cell BPs but displays normal affinity for the rat IGF-I receptor, failed to increase BP-3 abundance. 4) Human recombinant glycosylated [125I]BP-3 when added to cultured Sertoli cells was preserved in the medium when IGF-I or analogs with BP-3 affinity were present. 5) IGF-I, in dose-responsive manner, both retarded the disappearance from the medium of exogenously added human recombinant nonglycosylated BP-3 and decreased the amount of membrane-associated BP-3. These results indicate that whereas cAMP lowers BP-3 abundance in medium, most likely by markedly decreasing synthesis, IGF-I increases BP-3 accumulation by retarding its clearance by the Sertoli cell.

Animals↗
PubMed1991

Population-based study of surgery in juvenile onset Crohn's disease.

A geographically based cohort of 68 children with Crohn's disease was derived by sampling from Scottish Hospital In-patient Statistics. Surgical histories were examined and analysed by actuarial methods, and the nature of major operations performed was compared with operations for Crohn's disease in the Lothians' Surgical Audit. Fifty-four of the 68 patients were treated surgically, with a total of 135 operations (71 major, 64 minor). Fifty per cent of the cohort had a major operation within 5 years of onset of symptoms; median time to a second operation was 4 years. The types of major operation performed in juvenile onset patients differed significantly from those recorded in the Lothians' audit, with a high rate of exploratory laparotomy in younger patients (12 cases). With a mean follow-up of 7 years, 12 patients (18 per cent) have a permanent stoma. There were five deaths, three postoperative. This study highlights the frequency of surgical intervention in young people with Crohn's disease.

Adolescent↗
PubMed1991

Population-based study of surgery in juvenile onset ulcerative colitis.

A geographically based cohort of 37 children with ulcerative colitis has been derived by sampling from Scottish Hospital In-patient Statistics. Surgical histories were examined and analysed by actuarial methods, and the major operations performed were compared with operations for ulcerative colitis in the Lothians' Surgical Audit. Fourteen of the 37 patients had a total of 26 operations (15 major, 11 minor). Sixteen per cent had major surgery within 5 years of onset of symptoms, and the types of operation were similar to those recorded in Lothians' Surgical Audit. Operation rate was significantly lower than that for a parallel cohort of patients with Crohn's disease. With a mean follow-up of 7.4 years, seven (19 per cent) patients have a permanent stoma and there has been one death.

Adolescent↗
PubMed1991

A study of mid-arm and chest circumferences as predictors of low birthweight.

Nine hundred ninety-nine newborns were examined in order to determine the relationship between birthweight and mid-arm and chest circumstances. An early neonatal mortality rate of 51/1000 was recorded, being much higher for preterm (301/1000) than term babies (2.5/1000). Both mid-arm and chest circumference showed highly significant correlations with birthweight (r = 0.872, P less than 0.0001 and r = 0.918, P less than 0.0001, respectively). The correlation between weight and chest circumstances was upheld even for very small babies.

Arm↗