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Biomedical subjects

M Griffiths

Publications and source records attributed to M Griffiths.

At least 145 records · Page 8Linked to original sources
PubMed1991

Hypoxic pulmonary vasoconstriction in systemic sclerosis and primary pulmonary hypertension.

Reduction of pulmonary vascular resistance by a high inspired oxygen concentration is a common, but not universal phenomenon in patients with pulmonary vascular disease of varying etiology that may determine their response to long-term domiciliary oxygen therapy. We therefore determined changes in PVR during oxygen therapy in two patient populations not previously studied: systemic sclerosis (n = 8, mean age +/- SEM, 44.5 +/- 5.4 years) and primary pulmonary hypertension (n = 7, mean age +/- SEM 38 +/- 7.8 years). All patients were hypoxemic (arterial oxygen tension, on air 9.5 +/- 1.2 kPa for SSc and 8.3 +/- 0.6 kPa for PPH, p greater than 0.05). Right atrial pressure, pulmonary artery pressure, pulmonary artery occlusion pressure, systemic arterial pressure, PaO2 and cardiac output by thermodilution were measured at three, 20-min intervals while inspiring air and again after inspiring 60 percent oxygen for 30 min. The PVR fell significantly with oxygen in patients with SSc from 797.6 +/- 179.2 to 610 +/- 151.6 dynes/s/cm-5 (p less than 0.01), and this fall correlated with baseline PAP and PaO2 prior to oxygen therapy (r = 0.86, p less than 0.025; r = 0.77, p less than 0.05, respectively). In patients with PPH, there was no significant fall in PVR with oxygen (from 969 +/- 80.2 to 851.9 +/- 91.2 dynes/s/cm-5, p greater than 0.05) and no predictor of a vasodilator response in individual patients. In SSc, hypoxic pulmonary vasoconstriction contributes more consistently to elevated PVR than in patients with PPH.

Adult↗
PubMed1991

Teenage gambling: a pilot study.

Structured interviews were conducted of 40 gamblers between 17 and 24 years of age. They were males who reported playing 3 or more times per week and spending 1 pound to 4 pound per session. Many were unemployed or at school.

Adolescent↗
PubMed1991

Major histocompatibility complex (MHC) complement deficiency, ancestral haplotypes and systemic lupus erythematosus (SLE): C4 deficiency explains some but not all of the influence of the MHC.

In 1982 we reported that among Caucasians with systemic lupus erythematosus (SLE) there is an increased frequency of C4A null. As this allele occurs on the HLA-A1,B8,BfS, C4AQO,B1,DR3 (8.1) supratype, we suggested this accounted for the reported association of B8 and DR3. Since then we have shown that many supratypes including 8.1 identify unique segments of DNA conserved from a common but remote ancestor. Many of these ancestral haplotypes (AH), including 8.1, carry disease genes and some bear C4 null. We have therefore tested the hypothesis that in SLE C4 null alleles are directly involved by examining (1) whether all or only some AH bearing C4 null alleles are increased, (2) whether C4 null is increased in all racial groups examined, and (3) whether C4 null is associated with the presence of antinuclear antibodies (ANA) in the absence of SLE. We performed HLA and complement allotyping on 62 Australian Caucasians and 9 Australian aborigines with SLE and on the 10 out of 133 healthy individuals with 7 or more international units of ANA. Our data confirm an association of C4A null in Australian Caucasians (gene frequency 0.30 versus 0.15 in controls) and show an increased frequency of C4B null in Australian aborigines (gene frequency 0.33 versus 0.22). A review of an extensive literature shows C4A and/or C4B null are increased in all racial groups examined. On the other hand, the HLA-A3,B7,BfS,C4A3,B1,DR2 (7.1) AH rather than C4 null is associated with ANA in health. Our data indicate that while C4 nulls contribute to MHC susceptibility, other genes are likely to be involved.

Alleles↗
PubMed1991

The isolation and amino acid sequences of echidna (Tachyglossus aculeatus) milk lysozyme I and II.

Comparative studies of monotreme proteins are of particular value in gaining an understanding of the origin of mammals and their interrelationships. The presence of two lysozyme variants, echidna lysozyme I and II, has been confirmed in mature milk samples of Tachyglossus aculeatus multiaculeatus and Tachyglossus aculeatus aculeatus respectively. A simplified procedure is described for their isolation. Their amino acid sequences, the first determined for a monotreme secretory protein, are unusual. They are shown to be c-type lysozymes, each consisting of a single chain of 125 residues (terminating at Cys 125). The only other known c-type lysozyme with this termination is that of pigeon eggwhite. Echidna lysozyme is unique in having no Cys at position 6, but at position 9. It has precisely the residues relevant to the binding of Ca(II), and most of the residues implicated in the galactosyl transferase modifier action of alpha-lactalbumin. However, the weak modifier action previously observed for variant I, prepared by a different method, was not found for the present preparation. The evolutionary significance of the results is discussed.

Amino Acid Sequence↗
PubMed1990

Metabolic rate and physical development in children at risk of obesity.

Children of obese (group O) and normal-weight (group N) parents who took part in a study of metabolic rates and food intakes when 3-5 years old were restudied 12 years later. There were striking differences between the sexes. Among the 15 adolescent boys, parental obesity predicted more rapid growth (but not adiposity) and an earlier decline in resting metabolic rate (RMR)/kg body weight, and childhood energy intake/kg body weight was not predictive. Among the 10 girls, the opposite pattern was observed; childhood energy intake/kg predicted both body size and adiposity, and parental obesity had less predictive value. The sex differences are consistent with the earlier maturation of girls, and the growth differences with the hypothesis that a low RMR/kg body weight is associated with a precocious pattern of growth and development in children predisposed to obesity.

Adolescent↗
PubMed1990

The effect of glutamine on murine splenic leukocyte responses to T and B cell mitogens.

Murine splenic leukocytes cannot be stimulated to synthesize [3H]-DNA by various concentrations of either the T cell mitogens, Concanavalin-A (Con-A) or phytohaemagglutinin (PHA) or the B cell mitogen, lipopolysaccharide (LPS), unless glutamine is present in the culture medium. The optimum concentration of the T cell mitogens (Con-A, PHA) remained constant for all levels of glutamine while that of the B cell mitogen (LPS) increased as the concentration of glutamine in the medium increased.

Animals↗
PubMed1990

Syphilis in art.

Explore the source record for details and available documents.

Culdoscopy↗
PubMed1989

Effect of cumulative courses of intraarterial cis-diamminedichloroplatin-II on the primary tumor in osteosarcoma.

Preoperative chemotherapy with intraarterial cis-diamminedichloroplatin-II (CDP) and mannitol diuresis was administered to the primary tumor in 42 patients with osteosarcoma. The dose was 150 mg/m2 and more than 90% of the infusions were administered during a 2-week period. On occasion this period was extended to 3 weeks because of temporary renal insufficiency or logistical circumstances. Definitive surgical specimens were prepared by means of an arteriogram-directed plane of dissection with mapping and random sections. Histologically, tumor destruction was evaluated in terms of necrosis, inflammatory response, and fibrovascular regeneration. Quantification of the percent of tumor necrosis was as follows: less than 40% (consistent with spontaneous necrosis and/or no chemotherapy effect); 40% to 60% (possible chemotherapy effect); 60% to 90% (chemotherapy effect--partial response); and 90% to 100% (complete response). Therapeutic efficacy also was correlated with the number of CDP courses (one to three, four to five, and six to seven) and tumor subtype. Significant therapeutic effect (greater than 60% destruction) was observed with four or more CDP courses (one of nine tumors [one to three courses] versus 26 of 33 tumors [four to seven courses] [P = 0.01]). More than 60% of the tumor destruction was observed in the following subtypes: osteoblastic (22 of 28), fibroblastic (three of six), and telangiectatic (two of five). These data demonstrate that four or more courses of intraarterial CDP are required to achieve optimum effects and that osteoblastic osteosarcoma is highly responsive.

Cisplatin↗
PubMed1989

Isolation, partial sequence and asynchronous appearance during lactation of lysozyme and alpha-lactalbumin in the milk of a marsupial, the common ringtail possum (Pseudocheirus peregrinus).

1. Lysozyme and alpha-lactalbumin from the milk of the common ringtail possum have been purified and partially sequenced. 2. The lysozyme had similar enzymic activity to the c-type lysozyme of the domestic hen and 43% homology over the N-terminal 49 residues. 3. alpha-Lactalbumin was present in the milk in two biologically active forms; the more acidic form had 66% sequence homology with the N-terminal 35 residues of red-necked wallaby, 54% with human and 43% with bovine alpha-lactalbumin. 4. SDS polyacrylamide-gel electrophoresis of milk samples showed that alpha-lactalbumin was present in the milk throughout lactation but that lysozyme first appeared only in mid-lactation. The implications of this functional adaptation are discussed.

Amino Acid Sequence↗
PubMed1989

Intraperitoneal radioimmunotherapy for ovarian cancer: pharmacokinetics, toxicity, and efficacy of I-131 labeled monoclonal antibodies.

Thirty-six patients with ovarian cancer were treated with intraperitoneal I-131 labeled monoclonal antibodies to tumor associated antigens. The activity of I-131 administered was increased from 20 mCi to 158 mCi and the pharmacokinetics and toxicity evaluated. Five patients who had developed HAMA (Human Antimouse Antibodies) were retreated, and the pharmacokinetics and toxicity of the first and second treatment compared. Patients receiving their first therapy (HAMA negative), had a maximum of 25% (range 19.8-39.8%) of the injected activity in their circulation. This was accompanied by severe marrow suppression at I-131 activities over 120 mCi. The 5 HAMA positive patients had only 5% injected activity in the systemic circulation (range 3.8-6%), with rapid urinary excretion and neglible marrow suppression. In 31 patients with assessable disease there were no responses in 8 patients with gross disease (nodules greater than 2 cms), partial responses in 2 out of 15 patients with nodules less than 2 cms, and complete responses in 3 out of 6 patients with microscopic disease. The non specific radiation dose to the peritoneal cavity was estimated to be less than 500 cGy by lithium fluoride TLD, and could not be expected to account for the responses seen.

Animals↗
PubMed1989

The association of Angelman's syndrome with deletions within 15q11-13.

The inheritance of Angelman's syndrome, a disorder characterised by mental retardation, epilepsy, ataxia, and a happy disposition, is debated because affected sibs occur less frequently than expected with autosomal recessive inheritance. After discovering two unrelated patients with a small deletion of the proximal long arm of chromosome 15, 10 further patients with Angelman's syndrome were reassessed. Five had apparently normal karyotypes, four had a deletion within 15q11-13, and one had a pericentric inversion, inv(15)(p11q13) involving the same chromosomal region. In the latter case, the healthy mother had the same pericentric inversion, indicating that the patient also had a submicroscopic mutation on his other chromosome 15. These data map the Angelman locus to 15q11-13 and suggest that de novo visible deletions (associated with a low recurrence risk) and autosomal recessively inherited cases combine to give an overall sib recurrence risk of less than 25%.

Ataxia↗
PubMed1989

Taking cervical smears in departments of genitourinary medicine.

The smear taking practices of departments of genitourinary medicine were investigated by telephone inquiry. Departments seem to be broadly and equally divided into those where the smear is taken before the cervix is wiped or endocervical specimens are taken for microbiology, and those where the smear is taken afterwards. In the unit at Guy's Hospital we compared cervical smears taken in both of these sequences and concluded that, to diagnose more cases of premalignant cervical disease, smears should be taken before any other cervical samples.

Female↗