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Biomedical subjects

K Hartiala

Publications and source records attributed to K Hartiala.

At least 19 recordsLinked to original sources
PubMed2000

Borrelia burgdorferi--induced oxidative burst, calcium mobilization, and phagocytosis of human neutrophils are complement dependent.

When Borrelia burgdorferi, the spirochete causing Lyme disease, is transmitted to a human, the complement system is among the first challenges facing the bacterium. Neutrophils are crucial leukocytes in the first line of host defense against bacterial infections. To investigate the role of complement in the Borrelia-induced activation of human neutrophils, oxidative burst, calcium mobilization, and phagocytosis induced by three subspecies of B. burgdorferi were studied. Each subspecies induced all observed neutrophil functions in a complement-dependent manner. Serum-derived factors bound to the surface of B. burgdorferi were found to be essential for the induction of the oxidative burst. The CD11b chain of CR3 was found to participate in the oxidative burst and calcium mobilization induced by B. burgdorferi.

Borrelia burgdorferi Group↗
PubMed1998

Tube phagocytosis, a novel way for neutrophils to Phagocytize borrelia burgdorferi.

Interactions between human neutrophils and Borrelia burgdorferi, the Lyme disease spirochete, were studied by dark-field microscopy combined with video technology. A previously unrecognized mechanism for neutrophils to phagocytize the spirochete was discovered. During phagocytosis, the spirochete attaches to the neutrophil head-on, the neutrophil forms a thin tubelike protrusion around the bacterium, and the fully covered spirochete is drawn into the cell.

Borrelia burgdorferi Group↗
PubMed1994

Clostridium perfringens in stool, intrapartum antibiotics and gastrointestinal signs in a neonatal intensive care unit.

In 1989, we observed in our neonatal intensive care unit (NICU), an increased number of infants with gastrointestinal signs, including five cases of necrotizing enterocolitis. Clostridium perfringens was found in 26% of newborns (n = 168) and was associated significantly with the occurrence of flatulence, distended abdomen, foul-smelling stools, diarrhea and blood in stool (all p < 0.001). C. difficile was found in 17% of the newborns (n = 72). Cesarean section, low gestational age and low birth weight were significantly associated with C. perfringens in stools (all p < 0.001). Treatment with antibiotics was not associated with occurrence of C. perfringens. However, in infants with C. perfringens, intrapartum antibiotics were associated with increased appearance of abdominal distension (p < 0.05). Thus the antibiotics, which disturb primary colonization, may also favor the pathogenic role of opportunistic gut bacteria, such as C. perfringens.

Anti-Bacterial Agents↗
PubMed1981

Indomethacin inhibits arachidonic acid metabolism via lipoxygenase and cyclo-oxygenase in hamster isolated lungs.

14C-Arachidonic acid (AA, 66 nmol) was injected into the pulmonary circulation of isolated perfused hamster lungs. The metabolites were analysed from the nonrecirculating perfusion effluent, which was extracted with ethyl acetate first at pH 7.4 (to extract unmetabolized AA, metabolites of lipoxygenase and HHT) and then at pH 3.5 for prostaglandins and thromboxanes. When indomethacin was infused into the pulmonary circulation, the metabolism of AA was decreased dose dependently. The amounts of all metabolites were decreased rather similarly by indomethacin. The present study indicates that indomethacin inhibits arachidonate metabolism via cyclo-oxygenase and lipoxygenase in hamster isolated lungs.

Animals↗
PubMed1979

Effects of tetraethyl lead on the activities of drug metabolizing enzymes in different tissues of the rat.

The present study describes the effects of tetraethyl lead on various drug metabolizing enzymes in different tissues of the rat. Tetraethyl lead was administered intraperitoneally to rats (250 mumol/kg) on two consecutive days. The animals were killed on day 3. Tetraethyl lead-treatment decreased the concentration of hepatic cytochrome P-450 (to 45 per cent of the control), the hepatic activity of aryl hydrocarbon hydroxylase (to 41 per cent of the control) and ethoxycoumarin deethylase (to 45 per cent of the control). Epoxide hydratase activity was enhanced in the liver (1.3-fold), kidney (3.3-fold), and small intestinal mucosa (4.7-fold). The activity of glutathione S-transferase decreased in the liver (to 69 per cent of the control) but increased in the kidney (1.5-fold) and small intestinal mucosa (1.7-fold). The glucuronidation of o-aminophenol was enhanced (2.2-fold) in the kidney of tetraethyl lead treated rats. It is concluded that exposure to tetraethyl lead brings about widespread changes in the ability of mammals to detoxify foreign compounds.

Animals↗