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Biomedical subjects

M Griffiths

Publications and source records attributed to M Griffiths.

At least 91 records · Page 5Linked to original sources
PubMed1994

Protective wear and instrument sterilisation/disinfection in UK general dental practice.

The 18,000 United Kingdom general dental practitioners registered for National Health Service (NHS) practice were surveyed in July 1991 to assess their current use of protective gloves, eyewear and masks, and instrument sterilisation. Nearly 7,000 (6,588) valid responses were obtained immediately; of these, 70% of practitioners wore gloves routinely for clinical work, but only 14.5% donned new gloves for each patient. About 60% wore protective eyewear routinely or all the time but 12% never wore eye protection, and only 36% of practitioners used masks. Autoclaves or chemical solutions were the most popular methods to disinfect handpieces, but less than half the respondents stated that handpieces were sterilised or disinfected after each patient use. Most respondents (81%) routinely used autoclaves for sterilisation of other instruments. Although the response rate to the questionnaire was low, the results indicate that, despite the risks of, and publicity about, cross-infection, a substantial number of NHS dental practitioners may not adequately disinfect or sterilise their equipment between patients.

Attitude of Health Personnel↗
PubMed1994

IgG2 associated hypergammaglobulinaemia in some Nigerians with HIV infection.

Concentrations of immunoglobulins (IgA, IgG and IgM) were measured in Nigerians with (HIV) infection. Considerable elevations up to two-fold the reference values were observed for IgG and IgM in the patient group as a whole but elevations in IgA concentration were least marked albeit significantly different from the healthy subjects. Elevation of a particular isotype was not always concomitant with elevation of the other major classes in the same patient. Overall, these elevations were observed in both symptomatic and asymptomatic infected subjects. Further analysis of IgG hyperglobulinemia showed that increases in this major class may be due to increased IgG2 subclass concentrations. It is suggested that elevation of IgG2 subclass in Nigerians with HIV infection and not IgG1 or IgG3 may be due to genetic and environmental factors rather than variation in the strain of the virus.

Case-Control Studies↗
PubMed1993

The phylogeny of the genus Yersinia based on 16S rDNA sequences.

The inter- and intrageneric relationships of the genus Yersinia were investigated by sequence analysis of the 16S rRNA gene. A stretch of approximately 1450 nucleotides was sequenced from representatives of ten of the eleven validly described species. Phylogenetic analysis revealed that yersinae form a coherent cluster within the gamma subgroup of Proteobacteria. The intrageneric relationship was characterized by five sublines with Y. enterocolitica, Y. rohdei, and Y. ruckeri forming separate sublines each represented by a single species. A separate subline was formed by Y. pestis, Y pseudotuberculosis and Y. kristensenii, while Y. mollaretii, Y. intermedia, Y. bercovieri, Y. aldovae, and Y. kristensenii formed a fifth subline. The phylogenetic distinctness of the yersiniae sublines is compared to published phenotypic properties and results of DNA-DNA similarity studies.

Base Sequence↗
PubMed1993

Isolation, partial characterisation, and amino acid sequence of alpha-lactalbumin from platypus (Ornithorhynchus anatinus) milk.

alpha-Lactalbumin was isolated from the whey fraction of platypus (Ornithorhynchus anatinus) milk by successive ion-exchange, hydrophobic interaction and gel-permeation chromatography. The purified protein modified the action of partially-purified galactosyltransferase from platypus milk to promote the synthesis of lactose, but had very little modifier effect on bovine galactosyltransferase. Platypus alpha-lactalbumin has 126 amino-acid residues (molecular mass about 14.3 kDa), including a three-residue insertion not found in other alpha-lactalbumins or c-type lysozymes. It appears to have two sites of post-translational modification, of which at least one is N-glycosylated, to give an apparent molecular mass of 23 kDa on SDS-PAGE. The platypus sequence shows a high degree of positional identity (41-48%) with the alpha-lactalbumins of other species. Although it has no lysozyme activity, platypus alpha-lactalbumin is more similar to mammalian lysozymes than is any eutherian or marsupial alpha-lactalbumin, suggesting that this monotreme protein has evolved more slowly than other alpha-lactalbumins.

Amino Acid Sequence↗
PubMed1993

The control of cross-infection in UK clinical dentistry in the 1990s: immunisation against hepatitis B.

Thirty thousand dentists and clinical ancillary staff in the UK were surveyed in July 1991 to assess the current state of immunisation against hepatitis B virus (HBV). About 11,000 responded immediately and nearly 94% of these had been, or were being, immunised against HBV. Nearly all dentists and therapists (94% in each group), 95% of hygienists, and 96% of dental surgery assistants had been immunised. However, one half of the respondents were at or approaching 5 years post-immunisation, the time when booster immunisation is recommended. About 53% of most responding clinical dental staff had been vaccinated 4 to 5 years before the survey, but, of these, nearly 81% had not had booster immunisation. Booster immunisation will now be indicated for most dental clinical personnel.

Dental Staff↗
PubMed1993

The role of glutamine and glucose analogues in metabolic inhibition of human myeloid leukaemia in vitro.

1. Glutamine analogues L-[alpha S,5S]-alpha-amino-3-chloro-4,5-dihydro-5-isoxazoleacetic acid (acivicin) and 6-diazo-5-oxo-L-norleucine (DON) have been shown to possess cytotoxic activity against a wide variety of animal and human xenografted solid tumours, however their potential in man has been limited by toxicity. 2. We have analysed the effects of acivicin and DON on glutamine utilization to determine whether the reason for the disappointing therapeutic profile is solely due to the inefficient inhibition of glutamine metabolism. 3. Human myeloid leukaemic cells treated with acivicin inhibited ribonucleotide biosynthesis but not energy production via glutaminolysis and had little effect on viability, whereas treatment with DON inhibited both ribonucleotide biosynthesis and glutamine oxidation and resulted in reduced viability. 4. Treatment of the myeloid leukaemic cells with the glucose analogue 2-deoxy-D-glucose in addition to DON potentiated the inhibition of de novo nucleotide biosynthesis, glutaminolysis and glycolysis, and caused a further reduction in cell viability. 5. These results provide further support for the essential role of glutamine in cellular metabolism, and indicate that use of the glutamine analogue DON in the treatment of acute myeloid leukaemia may be more clinically effective if used in combination with 2-deoxy-D-glucose.

Acute Disease↗
PubMed1993

Wide variation in patient response to midazolam sedation for outpatient oral surgery.

Intravenous midazolam in doses of between 0.07 mg/kg and 0.1 mg/kg has been recommended for sedation in dentistry and some medical procedures and investigations. This study examined the variable sensitivity of patients to midazolam. One hundred and thirty-four fit but anxious patients between the ages of 16 and 63 years received midazolam intravenously for sedation for minor oral surgery. Doses required ranged from 0.04 to 0.40 mg/kg. Nineteen patients required doses less than 0.07 mg/kg; 59 patients required doses greater than 0.1 mg/kg. The mean dose per kilogram required for males was significantly less than for females. The wide variation in sensitivity to midazolam is confirmed.

Adolescent↗
PubMed1993

Prevention of collagen induced arthritis in mice by deletion of T cell receptor V beta 8 bearing T cells with monoclonal antibodies.

Collagen induced arthritis (CIA) is an animal model of inflammatory polyarthritis. Immunotherapy with the monoclonal antibody F23.1, which deletes V beta 8 bearing T cells, significantly decreased the incidence of CIA in mice. Treatment with the monoclonal antibody 466B5, to delete V beta 6 bearing T cells in combination with F23.1 was no more effective than F23.1 alone and the CIA incidence in 466B5 treated animals was not significantly different from controls. Thus, the V beta 8 family of T cell receptor is expressed on self-reactive T cells in the CIA model of B10.RIII mice injected with porcine type II collagen.

Animals↗
PubMed1993

Identification of the 9G4 idiotope in systemic lupus erythematosus.

An idiotope designated 9G4 (9G4Id) is known to be a marker for immunoglobulins which utilize a particular VH gene, VH4-21. The idiotope has been found to be present on anti-DNA antibodies, and have been identified in 45% of sera from patients with SLE. This idiotope is strongly associated with lupus being very uncommon amongst the other autoimmune rheumatic diseases tested. This distinction is unlike virtually any of the other DNA antibody idiotypes described which are much more widely distributed. 9G4Id levels were found to fluctuate with disease activity in some lupus patients and this idiotope was detected in 3/11 SLE renal biopsies tested. Its presence is associated with the HLA markers A1 and B8 and raised 9G4Id levels are not simply a reflection of hypergammaglobulinaemia. Thus a new DNA antibody associated idiotope has been identified. Expression of the idiotope indicates that a notable proportion of anti-DNA antibodies have VH segments encoded by the same, or closely related genes, and that these restricted immunoglobulins are involved in the renal pathology found in SLE.

Humans↗
PubMed1993

Blood glutathione status during exercise: effect of carbohydrate supplementation.

Blood glutathione status and activities of antioxidant enzymes have been investigated during prolonged exercise with or without carbohydrate (CHO) supplementation. Eight subjects cycled at approximately 70% of maximal oxygen uptake to fatigue [134 +/- 19 (SE) min] on the first occasion (control, CON) and at the same work load and duration on the second occasion but with CHO ingestion during exercise. Blood reduced glutathione (GSH) concentration increased from 0.55 +/- 0.05 mM at rest to 0.77 +/- 0.09 mM after 120 min of exercise during CON (P < 0.01) but remained constant during CHO exercise. Blood glutathione disulfide (GSSG) levels were unchanged during CON and CHO exercise. Blood GSH + GSSG content and GSH/GSSG ratio were also significantly (P < 0.05) elevated during CON but not during CHO exercise. The increases in GSH and GSH + GSSG in CON were associated with decreases in plasma glucose and insulin levels. Activities of blood GSH peroxidase, GSSG reductase, and glucose-6-phosphate dehydrogenase were significantly increased during the CHO exercise, whereas only GSSG reductase activity was elevated during the CON ride. It is concluded that blood GSH increases during prolonged exercise and that CHO supplementation may prevent blood GSH increase possibly because of its inhibitory effects on hepatic hormonal releases, which stimulate GSH output.

Adult↗
PubMed1992

Perineal tears.

Explore the source record for details and available documents.

Episiotomy↗
PubMed1992

Familial mesothelioma. Details of 17 cases with histopathologic findings and mineral analysis.

Nine new cases of mesothelioma clustering in four families are described, and additional information is provided on four previously reported families. All of the members of these families had some exposure to asbestos. Diagnoses were confirmed histologically, and the relevance of the histologic pattern is discussed after the literature review. The lung mineral fiber burden was quantified in patients by transmission electron microscopic examination and energy-dispersive x-ray analysis, and this confirmed significant exposure to amphibole asbestos in all patients. Evidence supporting an increased incidence of mesothelioma in family members is discussed.

Aged↗