H Tchou | PubMed Health

PubMed1999

Antigen retrieval on epoxy sections based on tissue infiltration with a moderately increased amount of accelerator to detect immune complex deposits in glomerular tissue.

We wanted to examine the effect of antigen retrieval on epoxy sections where the tissue had been infiltrated by resin containing moderately increased amounts of accelerator. The concentration of accelerator DMP-30 (Tri(Dimethyl Amino Methyl) Phenol) was varied in the range of 0% to 4% in the infiltration step of the tissue processing. Some of the epoxy sections were fixed in osmium tetroxide, and for others this fixative was avoided. Immunogold labeling was performed on epoxy sections and LR-White sections of renal tissue with IgG-deposits, and the antibody used was anti-IgG. Antigen retrieval was performed by heating the sections in citrate buffer. The amount of immunogold labeling on retrieved sections increased according to the amount of accelerator the non-osmicated epoxy sections were based on in the infiltration steps. For the osmicated epoxy sections these differences were less pronounced. The immunogold labeling of retrieved epoxy sections was up to 70% of LR-White labeling. In addition to breaking fixation bond introduced by the chemical fixation, we believe that the antigen retrieval also breaks bonds between the epoxy resin and the embedded tissue. The combination of increased amount of accelerator in the tissue infiltration and antigen retrieval by heating the sections in citrate buffer is a good method for improving the immunolabeling of epoxy sections.

Animals↗

PubMed1999

Rheumatic carditis treated with high doses of pulsetherapy methylprednisolone. Results in 70 children over 12 years.

PURPOSE: To report the result of patients treated with IV methylprednisolone divided into three groups and compare their follow-up during the last 12 years. METHODS: Seventy children with active rheumatic carditis (76 episodes) in heart failure Class III and IV (NYHA) were studied. The diagnosis was based on modified Jones' criteria. After ruling out infections and strongyloidiasis, treatment with IV methylprednisolone bolus was started three times a week until the laboratory tests became negative. Patients were divided into 3 groups, according to the time of hospital admittance: Groups 1, 2 and 3, comprising of 40, 18 and 12 children, respectively. RESULTS: Eighteen children in Group 1 (45%) were in their 1st attack: 2 series of pulsetherapy were used in 10 (25%), 3 in 9 (23%) and 4 in 21 (52%). In Group 2, 14 cases (77%) were in their 1st attack: 2 series were used in 7 (39%), 4 in 9 (50%) and 5 in 2 (11%). The echocardiogram showed a flail mitral valve in 12 (66%) of these patients (1 death occurred after mitral valvoplasty). In Group 3, 6 patients needed 5 or more series of pulsetherapy and a flail mitral valve was present in 5 (41%). One child underwent mitral valve replacement while still in the active phase, after 8 series of pulsetherapy, and another died. The number of patients who needed 5 or more series was significantly higher in Group 3. CONCLUSION: There were variations in the presentation and evolution of the cases during these 12 year. The established pulsetherapy protocol continues to be useful to treat severe cases.

Adolescent↗