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Biomedical subjects

M Sandholm

Publications and source records attributed to M Sandholm.

At least 19 recordsLinked to original sources

Relevance of sensitivity testings (MIC) of S. aureus to predict the antibacterial action in milk.

Bacterial susceptibility testings were carried out in parallel Iso-sensitest broth (ISB) and bovine milk cultures using 16 antibacterials and 4 sensitive strains of mastitic isolates of Staphylococcus aureus. Bacterial activities were analyzed by continuous turbidity monitoring (broth cultures), continuous fluorometric monitoring of the resazurin-reducing redox activity, and by analyzing the triphenyltetrazolium (TTC)-reducing capacity at the end of the incubation period. To obtain an equipotent bacteria-suppressing activity, milk cultures required in general several times more antibiotic than the respective ISB cultures. Antibacterial activities of sulfadoxine-trimethoprim, vancomycin, novobiocin, macrolides, aminoglycosides and oxytetracycline were most effectively suppressed by milk. Aminoglycosides suffered additionally from reduction of oxygen in the incubation environment. The beta-lactams (penicillin G, oxacillin, cephalothin, ceftiofur, ampicillin, ampicillin-clavulanic acid), gentamicin and enrofloxacin showed extremely variable sensitivity results depending on the S. aureus/milk combination.

Animals

A comparative study of intravenous and rectal administration of propofol in piglets.

To compare the effectiveness of propofol given intravenously and rectally, ten piglets received propofol intravenously. On the next day, the same piglets and five other piglets were given suppositories containing propofol. Serial blood samples were collected for the analysis of propofol plasma concentration. The time course of the total plasma drug concentration was fitted into a bi-exponential function using a least square fitting regression computer programme. The volume of distribution was 2.5-2.8 l.kg-1, mean elimination half-life, 23.9 min and mean clearance 0.08 l.kg-1.min-1. The mean bioavailability by the rectal route was low. In contrast to the intravenously administered propofol, none of the piglets slept when given propofol rectally, reflecting the extremely low plasma propofol concentration. In veterinary medicine, propofol would seem to be clinically valuable for inducing intravenous anaesthesia, but would be ineffective when given rectally. The findings indicate that with the dosage forms used here, propofol would be clinically ineffective if given rectally to human infants and children.

Administration, Rectal

Automation of the resazurin reduction test using fluorometry of microtitration trays.

Microtitration plate technique and -fluorometry was applied to automate the resazurin reduction test for monitoring bacterial numbers in broth cultures and milk. The effect of resazurin and resorufin concentration, bacterial species, growth medium, pH, and redox potential on the fluorescence response was studied. The timing of the appearance of maximum fluorescence was directly related to the logarithm of the number of colony-forming units (log CFU). Fresh milk and heat-treated milk contain interfering redox systems. The technique based on microtitration plate fluorometry, when fully automated, seems to provide a high-capacity system for analyzing bacterial numbers in foodstuffs and other media.

Animals

Alpha 1-antitrypsin and total trypsin-inhibitor capacity in acute pancreatitis.

Twenty three patients with acute pancreatitis were studied to assess the serum alpha 1-antitrypsin levels as well as the total trypsin-inhibitor capacity. These parameters were found to be normal or increased, which is not the case with patients with chronic pancreatitis. The value of protease-inhibitor treatment in acute pancreatitis is doubted.

Acute Disease

IgA in blood and thoracic duct lymph: concentration and degree of polymerization.

Lymph fluid and serum samples from four mammalian species were studied forthe concentration and degree of polymerization of IgA. The results suggest that in the mouse, in the rat and in the dog circulating IgA represents only a small fraction of all IgA entering the blood stream from the lymph vessels. A majority of the input IgA of oligomeric type (13S, 11S and 9S) in these species is cleared rapidly. Monomeric IgA, and in the mouse and the dog the dimeric (9S) variety, dwell much longer in the blood; and because of this they form the majority of the circulating IgA. Blood concentration of IgA is high in man, a species whose blood seems to receive mostly monomeric IgA. It is much lower in the rat, mouse and dog, and in these species most of IgA entering the blood is probably oligomeric.

Animals

Desorption assay: a functional in vitro test for measuring the adhesion of E. coli on the urinary tract epithelium.

A functional test was developed to measure different adhesive properties of various Escherichia coli strains on the urinary tract epithelium. The test is based on initial incubation of everted canine ureteral segments in 2-hr cultures of E. coli (adsorption period), followed by sequential elutions in phosphate buffered saline. The release of bacteria (desorption rate) was measured from each elution by quantitative bacteriology. The function of the desorption assay was tested by showing different adhesive properties of various strains of E. coli. The strains isolated from infected canine urinary tracts showed high adhesion capacities superior to other strains of E. coli from different animal and/or tissue origin. This indicates a selective tissue and animal trophism determined by the strength of mucosal attachment. The test is also a valuable tool for measuring adhesion inhibiting substances in urine. The bulk of the adhesion inhibiting effect was localized in the urine ultrafiltrate.

Adhesiveness

Changes of lipoamide dehydrogenase and mitochondrial structure in selenium-deficient chicks.

A selenium deficiency in chicks produces degeneration and fibrosis of the pancreas. An investigation was undertaken to determine whether or not the activity of lipoic acid is impaired in the pancreas of selenium-deficient chicks. Enzymatic analyses of selenium-deficient chick tissues showed a reduction in lipoamide dehydrogenase both in pancreas and liver at a very early stage of growth. Using both direct measurements and sucrose-gradient cellular fractionation, it was found that the lipoamide dehydrogenase activity of the supernatant increased, and that of the mitochondria decreased in selenium-deficient as compared to normal chick livers. These results indicate an increased fragility of the mitochondrial membranes in selenium-deficient chicks.

Animals

Coagulation of serum by glutaraldehyde.

A semiquantitative method for the determination of the gamma-globulin in human serum was developed based on the observation that dilute glutaraldehyde solutions at serum pH first attack the most basic serum proteins, leading to a polymer (clot) consisting mainly of gamma-globulins. The clotting ability of serum by glutaraldehyde thus caould be used as an indicator of the gamma-globulin concentration.

Aldehydes

Determination of antitrypsin activity on agar plates: relationship between antitrypsin and biological value of soybean for trout.

A new method is described for determination of antitrypsin activity based on inhibition of trypsin solubilization of calcium caseinate in agar plates. The method was applied to analyze soybeans after graded heat treatments for their antitrypsin content. Biological determination of protein and energy values of the soybean samples showed direct correlation of these values with the destruction of antitrypsin as measured by the new method, using rainbow trout.

Animals

Pathogenesis of canine pyometra.

Escherichia coli strains associated with pyometra in 85 of 100 bitches investigated had an affinity for urinary tract epithelium and smooth muscle as well as for progesterone-stimulated endometrium and myometrium. The adherence via K-antigen seemed to be important for colonization of the pathogen during development of pyometra. urinary tract infection was detected in 23 of 32 bitches from which urine specimens were obtained. In these bitches, a strain of E coli identical to the strain in the infected uterus was isolated. It was concluded that subclinical urinary tract infection is associated with pyometra and that the uterus will be infected at early metestrus, when receptors for E coli are developed in the endometrium and myometrium, thus enhancing the colonization of bacteria in the uterus.

Animals