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Biomedical subjects

M Halvarsson

Publications and source records attributed to M Halvarsson.

5 recordsLinked to original sources

Polymers that reduce intraperitoneal adhesion formation.

BACKGROUND: Viscous macromolecules and phospholipids have been shown to reduce postoperative adhesion formation. The ideal agent, or combination of agents, still remains to be identified. METHODS: The effect of hydrophobically modified ethyl (hydroxyethyl) cellulose (HM-EHEC) and polyquarternium-24 (LM-200), two cellulose-derived polymers, and of sphingomyelin, was examined in an animal model. Adhesions were induced in the parietal peritoneum in a standardized manner and quantity, and the morphology of adhesion formation was evaluated after 7 days. RESULTS: A significant reduction in adhesion formation was seen in animals receiving LM-200 (P=0.013) and HM-EHEC (P=0.012) as a short-term treatment compared with controls given saline, but not in animals receiving sphingomyelin (P=0.733). Additional effects were seen in the animals receiving LM-200 as a prolonged treatment (P< 0.001) compared with controls. There was no difference in the magnitude of the inflammatory response between the groups. CONCLUSION: These results suggest that hydrophobically modified polymers are efficient in reducing adhesions, without affecting the inflammatory response.

Animals↗

Antithrombotic effect of two low molecular weight thrombin inhibitors and a low-molecular weight heparin in a caval vein thrombosis model in the rat.

A sensitive thrombosis model with a high reproducibility was developed in the rat, utilizing stasis of the caval vein and a standardized surgical trauma as the only thrombogenic stimuli. Since no procoagulant substances were used, the results of the present study might be relevant in a clinical situation. The antithrombotic effect of two recently synthesized low-molecular-weight thrombin inhibitors have been compared to dalteparin, (Fragmin) a low-molecular-weight heparin fragment. Each compound was studied at 8 different doses with 10 rats in each group. On a gravimetric basis, the thrombin inhibitor melagatran was twice as potent as dalteparin (ED50 16 and 33 microg/kg per h, respectively). The second thrombin inhibitor, inogatran, had an intermediate effect, with an ED50 of 24 microg/kg per h. No differences in antithrombotic effect were, however, found when the compounds were compared at anticoagulant equivalent doses (same APTT prolongation). A 50% reduction in the mean thrombus weight was obtained when APTT was prolonged to 1.2 to 1.3 times the pretreatment value.

Animals↗

An eleven year follow-up of delayed-type hypersensitivity testing for the identification of HIV-1 infected patients at increased risk of developing AIDS.

The objective of this study was to investigate whether testing of delayed-type hypersensitivity (DTH) to recall antigens could be used to identify HIV-1 infected patients at increased risk of death or developing AIDS. Eighty-five HIV-1 infected Swedish homosexual men were tested for DTH using a commercially available kit with 7 recall antigens (Multitest, Mérieux). The patients were followed prospectively for 11 years or until death. The 11-year actuarial progression rate to AIDS was 69% and to death 60%. Older age was identified as a factor predisposing to rapid progression independent of cell-mediated immunity measured by DTH. Patients with a subnormal DTH had a significantly more rapid progression to AIDS and death than did patients with normal DTH, and the time between AIDS diagnosis and death was shorter. For patients with a multiscore (MS) < 10 mm, the median time to AIDS was 59 months, the median time to death 88 months, and the median time from AIDS diagnosis to death 11 months, compared to 106, 139, and 25 months, respectively, for patients with MS > or = 10 mm. Of the individual antigens, only a negative reaction to tuberculin was independently predictive of progression to all 3 endpoints, while a negative reaction to tetanus was independently predictive of progression to death. Thus, determination of DTH improves the early recognition of patients at increased risk of progressive disease.

Acquired Immunodeficiency Syndrome↗

Parvovirus B19 infection in HIV-1 infected patients with anemia.

Serum samples were analysed for IgM and IgG antibodies to parvovirus by ELISA and for parvovirus B19 DNA by polymerase chain reaction (PCR) in 69 HIV-1 infected Swedish patients with anemia and in 37 HIV-1 infected subjects without anemia. In 5/69 anemic patients, parvovirus B19 DNA was detected despite the lack of IgM antibody activity to the virus. The detection of parvovirus B19 DNA was significantly correlated to the degree of anemia in the anemic patients. In two patients who had a chronic anemia, a persistent parvovirus infection was detected by PCR, but not by serology, for 1 and 1.5 years, respectively. The results suggest that persistent parvovirus infection is a rare cause of anemia, but important to identify, since the infection is potentially treatable with intravenous immunoglobulin.

AIDS-Related Opportunistic Infections↗