PubMed Health⌕ Search

Biomedical subjects

A Schacht

Publications and source records attributed to A Schacht.

6 recordsLinked to original sources
PubMed2000

Vaccine properties of antigens entrapped in microparticles produced by spray-drying technique and using various polyester polymers.

The present study investigated the suitability of various microparticles produced by spray-drying technique to entrap and preserve the physiochemical and biological properties of an antigen. These microparticles were constituted either by poly(lactide) polymers characterized by various molecular weight or poly(lactide-co-glycolide) polymers. The recombinant 28 kDa glutathione S-transferase of Schistosoma mansoni (rSm28GST) characterized by major epitopes involved in the active site of this enzyme was selected as model antigen. The microparticles were characterized by a mean size </=5 microm and an antigen loading of approximately 2% (w/w). The analysis by SDS-PAGE electrophoresis of the rSm28GST released from microparticles confirmed the conservation of its physicochemical characteristics. The conservation of the native structure of the entrapped antigen was confirmed by detecting its enzymatic activity after release from microparticles. A single intraperitoneal immunization of mice with rSm28GST entrapped in microparticles resulted in a specific antibody response, which remained high for at least 7 months. The analysis of the isotype profile indicated that immunized mice primarily produced anti-rSm28GST immunoglobulin (Ig) G1 with the coexistence of lower IgG2a and IgG2b levels. Finally, the recognition of the major epitopic regions and the neutralization of the enzymatic activity of the rSm28GST by the antisera confirmed the specificity of the response against the native structure of the antigen. These results confirmed the integrity of the entrapped antigen. Moreover, our results supported the hypothesis that the duration of antigen release is the limiting factor for the duration of antibody production. Indeed, the use of polymers characterized by different molecular weights allowed us to modify the duration of the immune response. Together, these results demonstrated that microencapsulation of an antigen by spray-drying preserved its crucial characteristics required to generate an effective humoral immune response after a single-dose administration.

Animals↗
PubMed1992

Satanism as a response to abuse: the dynamics and treatment of satanic involvement in male youths.

Male youths from abusive family environments may be particularly vulnerable to recruitment into satanic cults. Families that are abusive, devalue or invalidate the abused child's feelings, blame the child for the family's problems, and view the world in rigidly moralistic terms create environments in which the youths are likely to identify with the aggressor and label themselves as evil. These youths, who may have poor social skills and feelings of anger, low self-esteem, self-blame, depression, powerlessness, and isolation as a result of the abuse, may use satanic involvement as a means of legitimizing their experience and differentiating from a negatively enmeshed and/or abusive family system. In this paper, the etiological factors and treatment approaches of ten hospitalized boys who had voluntarily involved themselves in repeated group satanic activities during their adolescence are described, and two case illustrations are given. Recommendations for understanding and treating such cases are provided.

Adolescent↗
PubMed1975

[Continuous negative pressure (cnp) in infants with idiopathic respiratory distress syndrome (irds) (author's transl)].

13 unselected premature infants with idiopathic respiratory distress syndrome (IRDS) have been treated with continuous negative pressure (CNP). A chamber was applied to the infants' body, so that the head remained outside in normal atmospheric pressure. 4 infants died during the period of treatment. 6 out of 13 differently treated IRDS-infants died over the same 6 months period. In comparison 18 out of 27 infants with IRDS died the previous year, during the same period. The frequency of IRDS in both observation periods was the same, as was the therapy of acidosis and hypoxia. The infants responded to CNP with decreased respiratory frequency, lessening of "grunting" and return of a pink skin color. Pathological examination of 3 out of 4 deceased infants in the study group revealed both atelectases and some degree of interstitial emphysema and widened capillaries. No intravascular hyaline thrombi were seen. The remaining infant died with clinical signs of coagulopathy (no autopsy). Of the 9 surviving infants in the study group one developed a hydrocephalus and subsequent mild psychomotor developmental retardation. We conclude that the CNP therapy in the chamber is an asset to the treatment of early and medium-severe cases of IRDS. We believe, that early application might prevent development of severe IRDS. The method is not recommended for severe cases.

Carbon Dioxide↗