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Biomedical subjects

E Gustafsson

Publications and source records attributed to E Gustafsson.

25 records · Page 2Linked to original sources

Maternal antibodies protect immunoglobulin deficient neonatal mice from mouse hepatitis virus (MHV)-associated wasting syndrome.

PROBLEM: Neonatal mice nursed by dams lacking immunoglobulins (Igs) may often suffer from lethal runting if raised under conventional conditions. The present study was performed in order to clarify a) the cause of the wasting syndrome and b) the protective role of antigen-specific milk antibodies. METHOD: Ig-deficient mouse embryos in a conventional environment were embryo-transferred to specified pathogen free (SPF) dams. Neonatal growth, mortality, and health status of mice from both environments was recorded. Suspected presence of mouse hepatitis virus (MHV) was tested by RT-PCR. Protective effects on neonatal mortality of milk containing different titers of anti-MHV antibodies were investigated in cross-fostering experiments. RESULTS: The SPF colony of Ig-deficient mice exhibited no breeding problems, whereas Ig-deficient neonates in the conventional environment suffered from lethal wasting syndrome. Serological screening of the mice kept in the two environments revealed that mice in the conventional room had high titers of antibodies against mouse hepatitis virus. Presence of MHV in runting neonates was confirmed by pathological examinations and RT-nested-PCR using MHV genome specific primers. Milk containing high titers of anti-MHV antibodies, when provided for 8 days or more, completely prevented Ig-deficient neonates from developing wasting syndrome in the conventional environment. CONCLUSION: These findings show that the neonatal wasting syndrome is associated with the presence of MHV and that neonates are efficiently protected by MHV-specific antibodies in the milk.

Animals↗

Pregnancy in B-cell-deficient mice: postpartum transfer of immunoglobulins prevents neonatal runting and death.

Mice lacking functional B cells because of a genetic deletion of the mu chain (IgM) gene were used to investigate the role of perinatal and postnatal transfer of maternal IgG in neonatal growth. Our results confirmed that immunoglobulin (Ig)-deficient mice successfully complete pregnancy and deliver healthy offspring. However, neonates nursed by Ig-deficient mothers showed growth retardation (runting) and high mortality during their first 10 days of life. This fatal course was seen whether or not the neonates were Ig-deficient. Cross-switching litters from phenotypically normal mothers to Ig-deficient mothers immediately after birth showed that perinatal Ig transfer normalized neonatal development for 10 days, but was not sufficient to sustain survival during the later part of the neonatal period. On the other hand, all Ig-deficient litters nursed by normal foster mothers showed normal development and 0% neonatal mortality. Administration of mouse IgG to an Ig-deficient mother or a neonate during the first critical week prevented runting. We assume that the growth- and health-promoting effects of IgG during early neonatal life are attributable mainly to the transfer of passive immunity to environmental pathogens. However, the finding that monoclonal IgG antibodies also enhanced neonatal growth and survival suggests that IgG-dependent growth-promoting mechanisms could be involved as well.

Animals↗

Quadriceps function and training after knee ligament surgery.

A follow-up study of 30 patients operated on for knee ligament injuries was performed with measurements of maximal isometric and isokinetic (angular velocity 30, 42, 120 degrees/s) torque for knee extension and muscle biopsy from vastus laternalis. The maximal torque values of the operated side were reduced in spite of resumed physical activities and athletic training. Isokinetic training, weight training (10 RM), and self-training were compared. All training groups increased their muscle strength with the largest increase for the isokinetically trained group. Before training, the mean fiber areas were somewhat low, especially for type II fibers and there was a tendency for an increase after training. There was no significant change in ATP, CP, and contractile enzyme activities with training. With the isokinetic training principle, maximal torque can in contrast to weight training be achieved through the whole range of motion, which may explain its larger training effect.

Adolescent↗

Lethality and EROD-inducing potency of chlorinated chrysene in chick embryos.

Chrysene was non-specifically chlorinated and the toxic potency of the mixture formed was studied. The chlorinated mixture was considerably more potent than the parent compound in terms of embryolethality and EROD and AHH induction in a 2-week test in chick embryos. The chlorinated chrysene caused anomalies, including edema and beak defects, similar to those previously found after treatment of chick embryos with coplanar PCBs. Chlorinated chrysene was also much more potent than chrysene as an inducer of EROD in a 72-hour test in chick embryos in ovo and in chick embryo liver in vitro. It seems that the mechanism of toxicity of chlorinated chrysene in chick embryos is similar to that of the coplanar PCBs and other Ah receptor ligands. The effects of the chlorinated mixture were mainly accounted for by 6- chlorochrysene and 6,12-dichlorochrysene.

Animals↗