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Biomedical subjects

C H Thompson

Publications and source records attributed to C H Thompson.

139 records · Page 8Linked to original sources
PubMed1981

Secretion of saliva by the rabbit mandibular gland in vitro: the role of anions.

Salivary glands form their secretions by first elaborating an isotonic plasma-like primary fluid in the endpieces and then modifying the composition of this secretion during its passage along the gland duct system. We have studied the role of extracellular anions in both primary secretion and ductal modification with a recently developed technique for isolation and perfusion of the rabbit mandibular gland. Neither of the major extracellular anions (Cl- or HCO-3) is essential for primary fluid secretion. HCO-3 can be removed altogether and replaced with Cl- without diminution in secretory rate, provided that extracellular pH is maintained at 7.4, and its replacement with acetate actually enhances secretion. Complete replacement of Cl- with Br- also enhances secretion and replacement with I-, NO-3, CH3SO-4 or isethionate supports secretion but at progressively diminishing rates. Our data do not yet allow us to distinguish between an electroneutral Na+-Cl- cotransport model or a double countertransport (Na+-H+ plus Cl--HCO-3) model as the basis of primary salivary secretion, or to propose any more suitable alternative model. With respect to ductal modification of the primary saliva, HCO-3 omission inhibits ductal Na+ absorption (i.e. salivary Na+ concentration rises). This inhibition is probably related to an effect of pH on the postulated Na+-H+ exchanges mechanism in the luminal duct membrane since it can also be induced by lowering perfusate pH, and reversed by substitution of perfusate HCO-3 with acetate (which enters saliva) but not HEPES (which does not enter the saliva). Substitution of perfusate Cl- with other anions seems not to inhibit ductal Na+ and K+ transport markedly.

Acetylcholine↗
PubMed1981

A prospective analysis of silver sulfadiazine with and without cerium nitrate as a topical agent in the treatment of severely burned children.

Previous studies have indicated that combining cerium nitrate with silver sulfadiazine (Silvadene, Marion Labs) yields a superior topical agent for the treatment of burns. Cerium nitrate in silver sulfadiazine was tested in a controlled study with silver sulfadiazine alone. The study population consisted of two groups of children suffering burns greater than 30% of the body surface. The patients ranged in size from 1 to 21 years. The study period was for the first 10 weeks of hospitalization. Quantitative surface cultures were used to monitor burn wound flora. No superiority for the silver sulfadiazine-cerium nitrate combination was demonstrated. In fact, cultures indicate a significantly greater percentage of Gram-negative pathogens in patients treated with the cerium mixture. Cerium nitrate could possibly prove of greatest benefit if used as a reserve therapy for colonizing organisms which do not routinely respond to silver sulfadiazine.

Administration, Topical↗
PubMed1980

The surface phenotype of a suppressor cell of delayed-type hypersensitivity in the mouse.

Delayed-type hypersensitivity (DTH) to horse red blood cells was induced in cyclophosphamide-treated CBA/H mice. The DTH reaction, represented by an increase (0 x 8--1 x 0 mm) in footpad thickness 24 h after secondary challenge, could be suppressed by the adoptive transfer of 10(7) splenic lymphocytes from syngeneic mice primed with 10(9) HRBC. The surface antigenic phenotype of the suppressor cell was determined by the formation of EA, EAC, or Ig rosettes followed by depleting the rosetted populations on Isopaque-Ficoll. The suppressor cell was found to be Ig-, FcR- and CR-, although some suppression was observed with FcR+ cells. Cell depletions with cytotoxic alloantisera and rabbit complement further characterized the suppressor cell as being Thy-1+, Ly-1+, 2-, 3-, 4-, 5+, 6+, 7-, Ia- and IJ-. This cell surface phenotype if unique and differs from the Ly-1-, 2+, 3+, I-J+ suppressor cell of antibody formation and from the recently described Ly-+, 2+, 3+ feedback suppressor T cell.

Animals↗
PubMed1978

Concentration of antibiotics in normal bone after intravenous injection.

The concentrations in serum, cancellous bone, and cortical bone of three antibiotics--nafcillin, cefazolin, and gentamicin--were measured in eleven normal dogs. All antibiotics rapidly penetrated into bone. The peak concentration in serum was reached within twenty minutes of intravenous injections, and the concentration in bone generally paralleled that in serum. Cancellous bone had higher concentrations than did cortical bone because of the admixture of blood.

Animals↗
PubMed1976

The effect of patellectomy on knee function.

Thirty-three patients were evaluated after patellectomy for subjective complaints, objective physical findings, quadriceps strength, and knee motion during activities of daily living. Partial and complete patellectomy caused an equal loss of active and passive range of motion. Complete patellectomy resulted in greater ligament instability, quadriceps atrophy, and loss of quadriceps strength compared with partial patellectomy. Complete patellectomy casued a reduction in the degree of stance-phase flexion during level walking and negotiating stairs.

Activities of Daily Living↗
PubMedDate not supplied

Quantitative analysis by 31P magnetic resonance spectroscopy of abnormal mitochondrial oxidation in skeletal muscle during recovery from exercise.

We use the hyperbolic relationship between cytosolic [ADP] and the rate of phosphocreatine (PCr) resynthesis after exercise to estimate the apparent maximum rate of oxidative ATP synthesis (QMAX). We examine data from some human diseases in which mitochondrial oxidation may be impaired (due to reduced mitochondrial numbers, intrinsic mitochondrial defect or impaired vascular supply). Muscle responds to impaired oxidation by stimulating anaerobic ATP synthesis and/or by increasing [ADP], the stimulus to the mitochondrion. However, these responses interact: [ADP] depends on pH and [PCr], and lactic acid production tends to lower [ADP] (by lowering pH), while proton efflux has the opposite effect. We identify four patterns of results: (A) in mitochondrial myopathy, apparent QMAX is reduced and [ADP] is appropriately increased, because increased proton efflux reduces the pH change in exercise despite increased lactic acid production; (B) in some conditions (e.g., cyanotic congenital heart disease) apparent QMAX is reduced but there is no compensatory rise in [ADP], probably because anaerobic ATP synthesis during exercise is increased without increase in proton efflux; (C) in other conditions (e.g., myotonic dystrophy) [ADP] is increased during exercise but apparent QMAX is normal, suggesting either an increase in proton efflux and/or decrease in anaerobic ATP synthesis during exercise; (D) there are also conditions (e.g., respiratory failure) where, despite impaired oxygen supply, both apparent QMAX and end-exercise [ADP] are normal. We also discuss the metabolic conditions under which end-exercise [ADP] is increased by a mitochondrial defect.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenosine Diphosphate↗
PubMedDate not supplied

Close relationship between equine and human molluscum contagiosum virus demonstrated by in situ hybridisation.

To determine whether the virus responsible for human molluscum contagiosum (MCV) is the causal agent of a similar disease in horses, in situ hybridisations using cloned fragments of human MCV DNA labelled with digoxigenin were carried out on formalin-fixed biopsy sections of lesions from two horses with molluscum contagiosum-like skin lesions. In both instances there was evidence of specific hybridisation of the labelled probe to target DNA in the sections under high stringency conditions, identified by the development of a deep blue-purple stain in the cytoplasm of cells in the stratum spinosum and stratum granulosum of the lesions and the absence of non-specific hybridisation in adjacent non-lesional areas of the epidermis. These results indicate that on the basis of very close homology of their viral DNA sequences, the causative virus of equine molluscum contagiosum is either identical with, or very closely related to, its human equivalent.

Animals↗
PubMedDate not supplied

Clinical and virological associations between external anogenital warts and cervical HPV infection in an STD clinic population.

To determine the significance of overt anogenital warts as indicators of human papillomavirus (HPV) infection of the cervix, 177 women attending a Sydney STD clinic were screened for evidence of cervical HPV infection using clinical criteria together with cytology and HPV DNA dot hybridization. HPV DNA probing was also performed on biopsies of 50 exophytic warts. A very high prevalence of both anogenital warts (40%), and of cervical HPV infection (58%) was indicated in this group of women. In the exophytic warts, HPV types 6/11 were most commonly detected, whereas the rates of detection of types 6/11 and 16/18 in the cervix were similar. Of the 87 women with evidence of cervical HPV infection, 57 (66%) had a history of either past or current overt exophytic anogenital warts; while the corresponding figure for the 90 women with no evidence of cervical infection was 45 (50%). Cytological evidence of dysplasia (CIN I-III) was detected in 13 (7%) of the cervical smears: of these, 4 were positive for HPV 16/18 only, 2 for 6/11 only and 4 for both 6/11 and 16/18.

Biopsy↗
PubMedDate not supplied

Clinical and molecular aspects of molluscum contagiosum infection in HIV-1 positive patients.

Molluscum contagiosum virus (MCV) lesions from 31 human immunodeficiency type 1 (HIV-1) positive patients and 54 HIV-1 negative adult control patients were examined for the presence and type of MCV DNA by high stringency Southern hybridization using 32P-labelled or digoxigenin-labelled MCV DNA probes. Of the 83 patients whose lesions contained detectable MCV DNA, 77 were infected with a single type of MCV (16 with MCV 1; 29 with MCV 1v; 30 with MCV 2; and 2 with MCV 2v). Five patients had apparent double infections, with hybridization results indicating the presence of various combinations of MCV 1 or 1v and MCV 2 or 2v. When these results were analysed in the light of clinical data no correlations were found between the MCV type(s) detected and the clinical stage of HIV-1 infection; nor between the MCV types and the anatomical site of the lesions or persistence of infection. However, the HIV-1 positive patients were significantly more likely to be infected with MCV types 2 or 2v than were the controls (17/29, 59% versus 15/48, 31%; P less than 0.05). Since a concurrent study of MCV lesions in children aged 15 years or less has shown that the percentage of infections attributable to MCV 2 or 2v is extremely small (3%), this finding suggests that MCV lesions in HIV-1 positive patients are attributable to adult-acquired MCV infection rather than to reactivation of a childhood infection.

Adult↗
PubMedDate not supplied

No effect of blood transfusion on muscle metabolism.

31Phosphorus magnetic resonance spectroscopy allows examination of skeletal muscle bioenergetics in vivo. The forearm muscle of four male patients receiving regular blood transfusions for myelodysplastic anaemia showed increased acidification and phosphocreatine depletion during exercise (compared to six age-matched male controls). Transfusion produced no significant improvement in these measurements or in the estimated maximum oxidative capacity of the muscle. We conclude that transfusion of patients with chronic anaemia (haemoglobin of 8-9 g/dl) does not improve skeletal muscle oxidative metabolism.

Aged↗