PubMed Health⌕ Search

Biomedical subjects

S Griffiths

Publications and source records attributed to S Griffiths.

At least 73 records · Page 4Linked to original sources
PubMed1987

Localization of antigen on lymph node dendritic cells after exposure to the contact sensitizer fluorescein isothiocyanate. Functional and morphological studies.

We have examined the cells involved in the development of contact sensitivity to FITC in CBA mice. After skin painting with antigen, the number of dendritic cells (DC) in the draining lymph nodes increased by 30 min, was maximal at 48 h, and returned to normal by 6 d. Derivation of some DC from Langerhans' cells of the skin was indicated from the presence of Birbeck granules observed in some DC isolated 24 h after skin painting. The DC acquired FITC and by 8 h there were two populations, one highly fluorescent and the other less fluorescent. The highly fluorescent cells were present between 8 h and 3 d after sensitization, and during this period the DC were potent at initiating primary proliferative responses of normal syngeneic T lymphocytes in vitro. Between days 3 and 5 the numbers of lymphocytes in the draining lymph node increased. During this period purified T lymphocytes did not express detectable levels of antigen, but enriched B cell populations expressed antigen transiently on day 1, 2, or 3 after exposure to antigen. The results showed that, during a 3-d period after exposure to antigen, DC expressed antigen and stimulated T cell proliferation. We speculate that low amounts of FITC binding selectively to veiled cells or lymph node DC in the first hours after exposure to antigen are not immunogenic but that Langerhans' cells acquire high levels of antigen, enter the nodes, and initiate immune responses.

Actin Cytoskeleton↗
PubMed1987

Demonstration of human papillomavirus types in paraffin processed tissue from human ano-genital lesions by in-situ DNA hybridisation.

A sensitive in situ hybridization technique for the demonstration of human papillomavirus (HPV) employing a biotin-streptavidin polyalkaline phosphatase complex has been successfully applied to formalin-fixed, paraffin processed tissue obtained from a selected series of patients with ano-genital lesions. Benign condylomata from males and females showed the presence of HPV 6 and 11. Two cases of vulval intraepithelial neoplasia showed HPV 16. Four cases of squamous carcinoma of the anal canal also showed HPV 16 in the tumour or in the adjacent pre-invasive neoplastic epithelium. A case of malignant transformation in a cervical condyloma was associated with HPV 6 and 11. This technique permits the retrospective evaluation of routinely processed material thus widening the investigative spectrum for HPV.

Adolescent↗
PubMed1987

Demonstration of human papillomavirus types 6 and 11 in juvenile laryngeal papillomatosis by in-situ DNA hybridization.

A study is reported in which an in situ hybridization technique for the demonstration of human papillomavirus (HPV) employing a biotin--streptavidin polyalkaline phosphatase complex has been successfully applied to formalin-fixed paraffin-processed tissue obtained from ten patients with juvenile laryngeal papillomatosis. In all cases, positive results were obtained for either HPV type 6 or 11. Normal vocal cord epithelium was negative.

DNA, Viral↗
PubMed1987

Sensitive in situ hybridisation technique using biotin-streptavidin-polyalkaline phosphatase complex.

A sensitive in situ hybridisation technique, using a biotin-streptavidin-polyalkaline phosphatase complex detection system, was successfully applied to smears of fresh cultured cells, frozen sections, and formalin fixed paraffin processed tissue: the procedure was successful for DNA-DNA hybridizations using a variety of DNA probes. The detection method is rapid, reliable, and economical producing a purplish-blue precipitate at the site of hybridisation and clearly visible by low power light microscopy.

Alkaline Phosphatase↗
PubMed1987

Low-output left ventricular failure in end-stage renal disease.

To determine the factors associated with low-output left ventricular failure (LVF) in endstage renal disease (ESRD), we performed echocardiography and gated cardiac scan on 217 nondiabetic dialysis and transplant patients. The prevalence of low-output LVF (ejection fraction less than 55% and left ventricular end diastolic diameter greater than or equal to 5.5 cm) in dialysis patients was 18% and in transplant patients 2%. The 26 patients with LVF were compared to 52 controls without LVF, matched by age, sex and year of starting treatment for ESRD, but not for current ESRD therapy. Mean age was 55 +/- (SEM) 14 years; 73% of the patients in both groups were males. Duration of treatment for ESRD was 5.6 +/- 4.3 years in patients, compared to 5.1 +/- 4.1 years in controls. Significant differences between LVF patients and controls included current treatment (73% of cases were on hemodialysis and 8% were transplanted, compared to 48 and 42%; chi 2 = 9.9, p less than 0.01), high serum creatinine, smoking and high serum alkaline phosphatase. There were no differences for current blood pressure, proportion on treatment for hypertension, left ventricular wall thickness, symptomatic ischemic heart disease, proportion with functioning vascular access, degree of weight gain between dialyses, hemoglobin level or high transfusion requirement. Multiple logistic regression demonstrated the most significant and independent variables associated with LVF were high alkaline phosphatase (suggestive of hyperparathyroidism), smoking and high serum creatinine levels (reflecting degree of uremia). Dialysis patients with LVF (n = 23) were compared to dialysis patients who had normal echocardiograms (n = 29).(ABSTRACT TRUNCATED AT 250 WORDS)

Cardiac Output, Low↗
PubMed1987

Class II histocompatibility antigens on human dendritic cells.

Histocompatibility antigens of the HLA D locus on the surface of human dendritic cells (DC) were visualized in the electron microscope using immunogold labelling. DC from peripheral blood expressed DR that was frequently concentrated at junctions between aggregating DC and lymphocytes or DC and macrophages. Labelling with an antibody to DQ was more diffuse and was not concentrated at points of cell-cell contact. The D locus antibody RFD1 labelled DC in distinct patches that were sometimes located at points of cell contact. Upon labelling DC with antibody to DR and incubating the cells at 37 degrees, some label remained on the cell surface but some was found in deep channels which appeared to be formed between veils at the surface of the cell and became internalized in membrane-bound structures. Under the same conditions, gold bound to DQ molecules remained on the surface of DC. Gold labelling RFD1 also remained mainly on the cell surface but there was occasionally internalization of patches into the cells through depressions in the cell membrane. The changes in distribution of the label on warming the cells suggests that materials bound to different D locus products may be 'processed' differently.

Cell Adhesion↗
PubMed1986

Bier's block--an improved technique.

A simple modification to the method of regional anaesthesia known as Bier's block is presented. This was applied to patients with Colles' fractures. In a controlled trial the technique produced anaesthesia more quickly than the other method.

Anesthesia, Conduction↗
PubMed1982

Trial of three-day and ten-day courses of amoxycillin in otitis media.

A randomised double-blind controlled trial compared three-day and 10-day courses of amoxycillin (25 mg/kg daily) in children with otitis media. Seventeen doctors from five centres admitted 84 children between the ages of 2 and 10 years. Symptoms and signs were measured on admission to the trial, on day 3, and on day 15. Mother's observations were recorded daily for 10 days. Audiograms were performed at four and 12 weeks after the end of the trial. The treatment groups showed little difference in the speed of resolution of symptoms and signs, the numbers of primary treatment failures, or the frequency of recurrent ear infections. There were no complications in either group. Most children with otitis media can probably be successfully and safely treated with no more than a three-day course of amoxycillin providing their progress is reviewed about the fifth or sixth day after treatment started. This policy could save over 1 million pounds annually in antibiotic costs.

Amoxicillin↗
PubMed1982

The abnormal morphology of polyoma-transformed baby hamster kidney cells is due to a failure to respond to 70K spreading factor.

The typical elongated bipolar morphology of baby hamster kidney (BHK) cells is not shown by polyoma-transformed BHK (Py-BHK) cells. Instead, the transformed line adheres poorly to tissue-culture plastic and cells have a more rounded morphology than the parent line. Plasma fibronectin is known to mediate the spreading of BHK cells, but when human serum is subjected to Sephacryl S-300 chromatography two peaks of spreading activity are eluted; the first is fibronectin and the second, which is quantitatively more significant, is a 70 K protein that is not related to fibronectin and stimulates spreading by a different mechanism. Py-BHK cells spread well in low concentrations of purified fibronectin but will not spread well in levels of serum that contain similar or greater concentrations of fibronectin. This is because fibronectin-mediated spreading of both BHK and Py-BHK cells occurs only in the presence of low concentrations of other proteins; albumin and other serum proteins inhibit fibronectin-mediated spreading. BHK cells spread under routine culture conditions in response to the 70 K factor rather than fibronectin. The altered morphology that results from viral transformation is due to a failure of the cells to respond to the 70 K spreading factor.

Animals↗
PubMed1980

The distribution of cell-spreading activities in sera: a quantitative approach.

Sephacryl S-300 gel filtration of animal sera is used to demonstrate that there are at least 2 components that promote the 'spreading' of cells in culture. A morphometric technique is described to quantitate the spreading process. For a number of cell strains and established cell lines the more quantitatively significant spreading factor is not fibronectin. Rather it is a component with fibronectin and seems to cause spreading via a different mechanism from that stimulated by fibronectin. Thus fibronectin will cause spreading in the absence of protein synthesis, whereas the smaller component requires protein synthesis. The kinetics of spreading are also different at all concentrations of the factors that are effective. By comparing the spreading promoted by whole sera with that promoted by separate serum fractions following chromatography we conclude that under normal conditions plasma fibronectin plays little part in initial cell spreading. This view is supported by the fact that fibronectin-depleted serum will stimulate cell spreading.

Animals↗
PubMed1978

Functional anatomy of lymph nodes. II. Peripheral lymph-borne mononuclear cells.

In the rabbit a number of large mononuclear cells with ruffled surface membranes travel from the skin and superficial tissues of the leg, via the lymphatics, to the popliteal lymph node: they constitute 40-50% of the total cell population in the afferent lymph. About 10% of these cells are actively phagocytic when tested in vitro and about 3% are found to contain Langerhans granules. After isotopic labelling the majority of lymph-borne mononuclear cells can be detected within the regional node for at least 24 hours; most being located in the paracortex and a few in the interfollicular cortex. It is proposed that these cells, including those containing Langerhans granules, belong to the "mononuclear phagocyte system." Possible functions of these lymph-borne cells are discussed with particular reference to antigen transport.

Adenosine↗