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Biomedical subjects

S Lloyd

Publications and source records attributed to S Lloyd.

At least 145 records · Page 8Linked to original sources
PubMed1989

Intestinal infection with Nematospiroides dubius selectively increases lactase expression by mouse jejunal enterocytes.

1. Intestinal structure, lactase (beta-galactosidase; EC 3.2.1.23) activity and alkaline phosphatase activity have been determined in mouse jejunal and ileal tissues before and during infection with the intestinal parasite Nematospiroides dubius. 2. Oral infection with small numbers of N. dubius larvae caused villus height, crypt depth and enterocyte migration rate to increase in the mouse jejunum. None of these effects occurred in ileal tissue. 3. Lactase activity also increased in jejunal, but not ileal, tissue of infected mice. This increase was associated with a doubling of the rate at which activity appeared in the brush-border membrane of enterocytes during migration over the basal regions of jejunal villi. Alkaline phosphatase activity in jejunal tissue remained unchanged in infected mice. 4. Attention is drawn to the fact that this is the first occasion when crypt cell hyperplasia has been found to be positively correlated with an increase in lactase activity and a decrease in cytotoxic/suppressor T-cells. Further work is needed to establish the primary cause of these effects.

Alkaline Phosphatase↗
PubMed1989

Immunologic and hematologic responses in ponies with experimentally induced Strongylus vulgaris infection.

Immunologic and hematologic responses were examined in 4 ponies with experimentally induced Strongylus vulgaris infection and in 5 helminth-free ponies. Two ponies were inoculated with 200 larvae and 2 were inoculated with 700 larvae of S vulgaris and then were reinoculated with the same numbers of larvae 34 weeks later. Initial response of the ponies inoculated with S vulgaris was S vulgaris antigen-induced lymphocyte response that developed 1.5 to 3 weeks after inoculation and did not persist. Development of antigen-reactive lymphocytes was followed sequentially by a biphasic complement-fixing antibody response, then biphasic eosinophilia. Antibody titer to S vulgaris antigen was higher in ponies inoculated with 700 larvae, compared with that in ponies given 200 larvae of S vulgaris. Also, the second peak in antibody titer and in absolute number of eosinophils was observed earlier in ponies inoculated with 700 larvae, compared with ponies inoculated with 200 S vulgaris larvae, and subsided before or from about 24 weeks after inoculation. The prepatent period for S vulgaris infection was 24 to 25 weeks. After reinoculation with S vulgaris, a degree of increased lymphocyte responsiveness was apparent but, by 17 weeks after reinoculation, only the primary peak in the absolute number of eosinophils indicated an anamnestic response. Essentially, antibody was not detectable after reinoculation.

Animals↗
PubMed1988

Seasonal allergic dermatitis in sheep.

The lesions of a seasonal dermatitis in sheep occurred mainly on the ventral surface of the animals, but in other respects they resembled those of 'sweet itch' in horses. They were primarily an immediate hypersensitivity response and the circumstantial evidence indicated that they were due to the bites of Culicoides species, possibly C obsoletus.

Animals↗
PubMed1988

Effect of methionine loading and endogenous hypermethioninaemia on blood mercaptans in man.

In five patients with cirrhosis given an oral methionine load, blood mercaptan concentrations were not significantly affected by neomycin and metronidazole therapy. Methanethiol and dimethyl sulphide rose after methionine to levels encountered in hepatic encephalopathy but in stable cirrhotics no neurological abnormalities were evident. In one patient with chronic hepatic encephalopathy there was no significant change in methanethiol, dimethyl sulphide or ammonia concentration 4 h after methionine when conscious state had deteriorated by two stages of encephalopathy. Elevations in blood methanethiol and dimethyl sulphide concentration in children with congenital hypermethioninaemia were not associated with any neurological or electroencephalographic features of hepatic coma. These studies do not support an important role for mercaptans in hepatic encephalopathy although a synergistic effect cannot be excluded. Furthermore, mercaptans appear to arise from endogenous metabolism rather than bacterial action in the gut.

Hepatic Encephalopathy↗
PubMed1987

Whole body leucine turnover and nutritional status in continuous ambulatory peritoneal dialysis.

1. Nutritional status and leucine turnover has been measured in ten patients with chronic renal failure before the onset of continuous ambulatory peritoneal dialysis (CAPD) and after 3 months treatment, and in five normal subjects. 2. Somatic muscle protein reserves, as judged by anthropometry and measurement of total body potassium, showed no significant changes after 3 months treatment and were not significantly different from normal. 3. Visceral protein reserves, as judged by serum albumin and plasma amino acids, showed a significant fall after 3 months CAPD and were also lower than in normal subjects. 4. Protein turnover was lower in uraemic than in normal subjects, but the balance between synthesis and breakdown was significantly higher and was maintained after 3 months on CAPD.

Amino Acids↗
PubMed1987

Short-term studies on the use of amino acids as an osmotic agent in continuous ambulatory peritoneal dialysis.

1. A 1% amino acid dialysis solution with a high concentration of the branched-chain amino acids has been compared with 1.36% glucose in short-term studies. 2. The 1% amino acid solution was as effective an agent as 1.36% glucose with respect to ultrafiltration and clearance of creatinine, urea and potassium. 3. Levels of branched-chain amino acids rose to the upper end of the normal range within 1 h and remained at this level over the entire period of the study. Total and non-essential amino acids had returned to baseline by the end of the cycle. 4. Blood glucose rose to significantly greater levels during the 1.36% glucose exchange than during the 1% amino acid exchange. There was an increase in serum insulin levels during both cycles; this was significantly greater with the 1% amino acid solution than the 1.36% glucose. 5. There was no evidence of short-term metabolic complications with the 1% amino acid solution.

Adult↗
PubMed1985

Antibody levels in adoptively immunized mice after infection with Babesia microti or injection with antigen fractions.

Specific IgG anti-Babesia antibodies could be detected by an ELISA test in the serum of adoptively immunized mice which subsequently were infected with Babesia microti. Initially, higher IgG antibody levels were present in the recipients of either untreated immune spleen cells or mitomycin C-treated immune spleen cells compared with the values in control mice which received the infection alone. Subsequently, a marked anamnestic response occurred only in mice which received untreated immune spleen cells and not in the recipients of mitomycin C-treated cells, demonstrating a requirement for proliferation of B memory cells in the anamnestic response. When mice were injected with either T or B enriched spleen cell subpopulations and infected with B. microti, the anamnestic antibody response in each animal correlated well with protection against infection. The stimulation of the adoptively transferred immune spleen cells in recipient mice by injection of B. microti antigen fractions prepared by DEAE cellulose chromatography increased the level of antibody production and protection against infection in these mice. A highly significant correlation between these two parameters could be demonstrated for certain antigen fractions.

Animals↗
PubMed1985

Sleep position training as treatment for sleep apnea syndrome: a preliminary study.

Ten male patients selected as having sleep apnea predominantly of the obstructive type associated with the supine sleep position on their evaluation night were trained for 1 additional night to avoid the back sleep position by wearing a gravity-activated position monitor/alarm on the chest. This device emitted an auditory signal if the patient remained supine for more than 15 s. The number of apneic events was significantly reduced, as were the number of episodes of significant O2 desaturation. While wearing the alarm, the apnea index of seven patients remained within or near normal limits. On a follow-up night, with only instructions to maintain the lateral decubitus posture, five patients remained significantly improved. Sleep position training may be appropriate as a single or interim treatment for a significant number of sleep apnea patients who have position-related obstruction.

Adult↗
PubMed1985

Humoral immune response of sheep to infection with Eperythrozoon ovis.

Circulating antibody was detected by an indirect fluorescent antibody test (IFAT) in the serum of sheep infected experimentally with Eperythrozoon ovis. Antibodies were first detected 15 to 32 days after infection with E ovis and titres peaked at 41 days. This antibody may be associated, at least in part, with protection against infection with E ovis since the initial increase in antibody titre coincided with a fall in the primary parasitaemia. A role for antibody is suggested further by the fact that the prepatent period of infection was prolonged by one day and the parasitaemia initially remained at low levels in infected sheep protected by passively transferred hyperimmune serum. Moreover, following primary infection, acquired immunity was manifest by a lack of parasitaemia following challenge infections while increased IFA titres were observed. No evidence of opsonic activity was observed in an in vitro erythrophagocytosis test in that neither mouse macrophages nor sheep monocytes phagocytosed E ovis infected or uninfected erythrocytes sensitised with hyperimmune serum.

Anaplasmataceae Infections↗
PubMed1984

Haematological and biochemical values in horses naturally infected with Strongylus vulgaris.

The concentrations of serum proteins (beta 1, beta 2, gamma, alpha 1, alpha 2 globulins and albumin) and absolute numbers of eosinophils, neutrophils and lymphocytes were examined in 64 naturally infected horses and ponies in which the number of larvae of Strongylus vulgaris in the cranial mesenteric artery and the severity of the lesion of verminous arteritis could be determined. The horses were grouped according to the number of larvae found and the severity of the arteritis. The results demonstrated that, although some significant deviation from a random distribution occurred in certain of the values (chi 2 test), there was considerable individual variation in the values obtained for individual animals within groups and overlap of the range of values between groups. Also the number of larvae present in the artery did not necessarily accurately reflect the severity of the arterial lesion. Thus, the parameters examined could not be used reliably to estimate the intensity of infection with S vulgaris in an individual animal.

Animals↗