An immunodominant haptenic epitope of carbamazepine detected in serum from patients given long-term treatment with carbamazepine without allergic reaction

An anticarbamazepine antibody was detected in the serum of a patient with severe carbamazepine-induced serum sickness. We found that the patient's T cells and IgG antibody recognized an epitope which appeared in subjects showing an allergic reaction, as well as that in subjects who showed no allergic reaction, after long-term carbamazepine therapy. These results show that an anti-carbamazepine immune response does not occur in the majority of subjects who undergo long-term carbamazepine therapy without developing allergic symptoms, although the immunodominant haptenic epitope of carbamazepine is present in their sera.     

Rat costochondral cell characteristics on poly (L-lactide-co-epsilon-caprolactone) scaffolds

This study was designed to examine the adhesion, proliferation, and morphology of chondrocytes on new scaffolds; and to examine these cells histologically for the ability of the chondrocytes to maintain chondrogenic properties after subcutaneous implantation into nude mice. Both 75:25 poly (L-lactide-co-epsilon-caprolactone) (75PLC) and 50:50 poly (L-lactide-co-epsilon-capro-lactone) scaffold (50PLC) were tested as a scaffold for rat costochondral resting zone chondrocytes in comparison with a type I collagen sponge scaffold (collagen scaffold). Both of the poly (L-lactide-co-epsilon-caprolactone) scaffolds (75PLC and 50PLC) were coated with type I collagen solution and the effects of the collagen coat (hybrid-PLC) were also examined. The hybrid-75PLC bound the same number of cells as the collagen scaffold, whereas the 75PLC and the 50PLC bound 60% and 50% fewer cells than the collagen scaffold, respectively. The cell growth on the scaffolds progressed with culture time in all scaffolds. Cell morphology was assessed by scanning electron microscopy for differences in the structure of cellular interaction. Chondrocytes on every scaffold maintained a spherical shape. The hybrid-PLCs were superior to the PLCs with respect to the number of cells attached. The PLCs had an advantageous degradation characteristic in that they retained their original shape better than the collagen scaffold. Additionally, in the PLCs seeded, the cells retained their integrity 4 weeks after implantation, although the volume of collagen scaffold decreased by 50%.     

Tumor necrosis factor-alpha in the placenta is not elevated in pre-eclamptic patients despite its elevation in peripheral blood

PROBLEM: Tumor necrosis factor-alpha (TNF-alpha) is present in human placental and uterine cells at the early and late stages of gestation and promotes the regulation of trophoblast growth and invasion. We evaluated whether TNF-alpha levels in the placenta and blood of pre-eclamptic women differed from those with normal pregnancies. METHOD OF STUDY: The subjects were 39 pregnant women carrying single fetuses (21 normal-pregnant and 18 pre-eclamptic patients). Their average gestational age at entry was 38-39 weeks. Peripheral blood was collected before the onset of labor and separated serum was stored at -20 degrees C. A tissue segment of the placenta was cut and frozen in liquid nitrogen immediately after delivery at -80 degrees C. The frozen placental tissue was added to phosphate-buffered saline. The tissue was fully homogenized and centrifuged. Separated supernatant was stored at -80 degrees C. TNF-alpha levels in separated serum and TNF-alpha and total protein (TP) levels in separated supernatant were measured. The presence of TNF-alpha in the placenta was evaluated by immunohistochemistry in five pre-eclamptic and five normal-pregnant patients. RESULTS: Serum TNF-alpha levels were higher in pre-eclampsia than in normal pregnancies. However, TNF-alpha/TP levels in the placenta did not differ significantly between the two groups. As for TNF-alpha immunostaining of trophoblastic cells in the placenta, it was weak in three and moderate in two of the normal pregnancies, while it was absent in two, weak in one, and moderate in two in the pre-eclampsia group. CONCLUSIONS: We demonstrated no significant increase in TNF-alpha/TP levels in the placenta in pre-eclampsia despite a significant increase in serum TNF-alpha levels. There was no strong immunostaining for TNF-alpha detected by immunohistochemistry in the pre-eclampsia group. These findings suggest that TNF-alpha in the placenta is not a key cytokine to interfere with normal trophoblast invasion into the myometrium in pre-eclampsia, and that sources other than the placenta may contribute to the elevated levels of TNF-alpha found in the circulation of pre-eclamptic patients.     

B-cell repertoire specific for an unfolded self-determinant of mouse lysozyme escape tolerance and dominantly participate in the autoantibody response

We previously found that autoantibodies against mouse lysozyme (ML) were strongly induced in normal BALB/c mice when immunized with mutant ML that has triple mutations rendering the dominant T-cell epitope of hen egg lysozyme (HEL), HEL 107-116. As T cells specific for HEL 107-116 were primed in these mice, the anti-ML immunoglobulin G (IgG) responses would be the result of collaborations between autoreactive B cells specific for ML and T cells specific for HEL 107-116. Serum IgG responses against ML were dominantly focused on the ML 14-69 region, indicating that B cells responding to the epitope escape tolerance. In the present study, we prepared several monoclonal antibodies (mAbs) specific for ML 14-69 and examined their antigen specificities in detail, to characterize the nature of the remaining B-cell repertoire specific for ML. mAbs specific for ML 14-69 interacted weakly with soluble, native ML, but the interactions were strengthened by denaturation of ML. The apparent affinity constants between these mAbs and ML showed an increase, ranging from six- to 80-fold, by denaturation of ML. Therefore, these mAbs were more specific for the denatured determinant than for the determinant in the native structure. These results indicate that a substantial number of autoreactive B cells, specific for the unfolded conformation of ML, escape tolerance and are dominantly involved in the autoantibody response to ML. Our finding provides important information to understand the naturally occurring autoreactive B-cell repertoire in normal mice.     

The effect of immunoglobulin G1 structure on macrophage binding to supported planar lipid monolayers.

We have studied the antibody-dependent binding of macrophages to supported planar lipid monolayers containing haptenated phospholipids (Tnp-Cap-DPPE). Eight monoclonal anti-TNP IgG1s, which had similar affinities to the TNP residues in solution and in the membranes, were used in the experiment. The results showed that mouse macrophages (P388D1 and J774.1) bound with different affinities to these IgG1-coated lipid monolayers. The monoclonal antibody shown to be deficient in macrophage binding was also relatively ineffective in activating complement. These results indicated that individual monoclonal antibodies of a given subclass may prove deficient in terms of the biological activities associated with the group as a whole.     

Epidemiology of Campylobacter jejuni isolated from patients with Guillain-Barré and Fisher syndromes in Japan

Campylobacter jejuni isolation is the standard for the diagnosis of this type of bacterial infection, but there have been no epidemiological studies of a large number of C. jejuni isolates from patients with Guillain-Barre syndrome (GBS) and Fisher syndrome (FS). For 13 years, stool specimens from GBS/FS patients have been sent from 378 hospitals throughout Japan to the Tokyo Metropolitan Institute of Public Health. A total of 113 strains (11%) were isolated from the stool specimens from 1,049 patients. The isolation rate did not differ by region. The rates were 22% for 449 patients with a history of diarrhea and 2% for the others. An additional 18 isolates were provided by various hospitals. There was no noticeable seasonal distribution in the onset of C. jejuni isolated from patients with GBS/FS. The male/female ratios were 1.7:1 for GBS and 2.2:1 for FS. The patient age range showed a peak in 10- to 30-year-old subjects who had GBS and in 10- to 20-year-old subjects who had FS. The predominance of young adults and male patients who had C. jejuni-associated GBS/FS may be related to the preponderance of young adults and male patients who had C. jejuni enteritis. The median interval from diarrhea onset to neurologic symptom onset was 10 days for GBS/FS. Penner's C. jejuni serotype HS:19 was more frequently present in GBS (67%) than in enteritis (6%) patients. HS:2 was more frequent in FS (41%) than in enteritis (14%) patients. These findings suggest that certain C. jejuni strains specifically trigger GBS and that others specifically trigger FS.     

Relative frequency of VP4 gene alleles among human rotaviruses recovered over a 10-year period (1982-1991) from Japanese children with diarrhea.

The relative frequencies of the Wa (corresponding to serotype P1A), DS-1(P1B), M37(P2), and AU-1(P3) alleles of the VP4 gene from rotaviruses collected from the stools of individuals in Japan between 1982 and 1991 were determined to be 83.1, 15.6, 0, and 1.3%, respectively, by a polymerase chain reaction-based typing assay.     

Characterization of rabies virus glycoprotein expressed by recombinant baculovirus.

A cDNA of the glycoprotein (G protein) gene of rabies virus Nishigahara strain was cloned and inserted into a baculovirus genome under the control of the polyhedrin promoter. Infection of Spodoptera frugiperda cells with this recombinant virus produced a large quantity of new protein instead of the parental polyhedrin protein. By immunofluorescent and immunoblotting analyses, the recombinant protein was antigenically similar to the authentic G protein. Its molecular mass estimated by sodium dodecyl sulfate polyacrylamide gel electrophoresis, however, was slightly smaller than that of the authentic one, and this observation was suggested to be due to the difference in glycosylation level between the two G proteins. The recombinant G protein expressed on the cell surface of the insect cells showed a fusion activity at low pH. The fusion activity was inhibited by antiserum against either whole virions or G protein of rabies virus.