Mapping antigenic sites of an immunodominant surface lipoprotein of Mycoplasma agalactiae, AvgC, with the use of synthetic peptides

As a first step toward the design of an epitope vaccine to prevent contagious agalactia, the strongly immunogenic 55-kDa protein of Mycoplasma agalactiae was studied and found to correspond to the AvgC protein encoded by the avgC gene. The avg genes of M. agalactiae, which encode four variable surface lipoproteins, display a significant homology to the vsp (variable membrane surface lipoproteins) genes of the bovine pathogen Mycoplasma bovis at their promoter region as well as their N-terminus-encoding regions. Some members of the Vsp family are known to be involved in cytoadhesion to host cells. In order to localize immunogenic peptides in the AvgC antigen, the protein sequence was submitted to epitope prediction analysis, and five sets of overlapping peptides, corresponding to five selected regions, were synthesized by Spot synthesis. Reactive peptides were selected by immunobinding assay with sera from infected sheep. The three most immunogenic epitopes were shown to be surface exposed by immunoprecipitation assays, and one of these was specifically recognized by all tested sera. Our study indicates that selected epitopes of the AvgC lipoprotein may be used to develop a peptide-based vaccine which is effective against M. agalactiae infection.     

Gender, suicidality and bipolar mixed states in adolescents

BACKGROUND: The purpose of this study was to determine the relationship between mixed states and suicidality among adolescent outpatients presenting with a DSM-IV defined major depressive episode (MDE). METHODS: Two-hundred and forty-seven adolescents meeting the criteria for MDE were screened for the presence of concurrent, intra-MDE hypomania/mania (i.e., mixed states). All patients were asked whether they had current suicidal ideation or had recently attempted any self-destructive physical act associated with the thought of dying (i.e., a suicide attempt). The data were subjected to analysis using univariate logistic regression. RESULTS: One hundred of the 247 (40.5%) adolescents were bipolar type I or type II. Of these, 82% were in mixed states. Of the patients with suicidal ideation, 62.8% were girls, and of those with histories of a suicide attempt, 69.4% were girls. Girls had more than twice the risk of having suicidal ideation (OR=2.2, p=0.004) and nearly 3 times the risk of having histories of a suicide attempt than boys (OR=2.87, p<0.0001). Being in a mixed state per se did not predict either suicidal ideation or a suicide attempt among all of the 247 patients. However, mixed states apparently independently contributed to the risk of (non-fatal) suicidal behavior among girls only. Of the mixed states, girls had nearly 4 times the risk of having made a suicide attempt compared with those without mixed states (OR=3.9, p=0.003). Age, presence of psychotic features and family history of mood disorder had little or no bearing on suicidality. LIMITATIONS: Correlational chart review study, no data collection on Axis I and Axis II comorbidity and adverse life-events. CONCLUSIONS: This report of greater suicidality in adolescent girls in a mixed state parallels the well-known adult literature of high frequency of mixed states in women. The findings are of relevance to the controversy of antidepressants and suicidality in juvenile depressives in that they identify a vulnerable group. In line with earlier suggestions by the senior author [Akiskal, H.S., 1995. Developmental pathways to bipolarity: are juvenile-onset depressions pre-bipolar? J. Am. Acad. Child Adolesc. Psych. 34, 754-763], our data highlight the public health importance of the wider recognition of bipolar mixed states in juvenile patients masquerading as unipolar depression. Finally, it appears to us that it is the failure of our formal nosology on mixed states--rather than the antidepressants per se--which is the root problem in this controversy.     

Laser-ultraviolet-A-induced ultraweak photon emission in mammalian cells

Photobiological research in the last 30 yr has shown the existence of ultraweak photon emission in biological tissue, which can be detected with sophisticated photomultiplier systems. Although the emission of this ultraweak radiation, often termed biophotons, is extremely low in mammalian cells, it can be efficiently increased by ultraviolet light. Most recently it was shown that UV-A (330 to 380 nm) releases such very weak cell radiation in differentiated human skin fibroblasts. Based on these findings, a new and powerful tool in the form of UV-A-laser-induced biophotonic emission of cultured cells was developed with the intention to detect biophysical changes between carcinogenic and normal cells. With suspension densities ranging from 1 to 8 x 10(6) cells/mL, it was evident that an increase of the UV-A-laser-light induced photon emission intensity could be observed in normal as well as melanoma cells. Using this new detection procedure of ultraweak light emission, photons in cell suspensions as low as 100 microL could be determined, which is a factor of 100 lower compared to previous procedures. Moreover, the detection procedure has been further refined by turning off the photomultiplier system electronically during irradiation leading to the first measurements of induced light emission in the cells after less than 10 micros instead of 150 ms, as reported in previous procedures. This improvement leads to measurements of light bursts up 10(7) photons/s instead of several hundred as found with classical designs. Overall, we find decreasing induction ratings between normal and melanoma cells as well as cancer-prone and melanoma cells. Therefore, it turns out that this highly sensitive and noninvasive device enables us to detect high levels of ultraweak photon emission following UV-A-laser-induced light stimulation within the cells, which enables future development of new biophysical strategies in cell research.     

Isokinetic knee joint test in "gonalgia sine materia"

Fifty-four subjects, aged between 20 and 35 years, divided into two subgroups, respectively 30 healthy subjects (17 males and 13 females) and 24 subjects with "gonalgia sine materia" (13 males and 11 females) underwent isokinetic exercise test in order to compare their dominant limb with the not dominant one as regard as the strength of extensor and flexor muscles of the knee. No statistically significant difference was found in any of the studied parameters in the comparison between the dominant limb and the not dominant one, both within the subgroup of healthy subjects and within the subgroup of subjects with "gonalgia sine materia". Authors conclude that psychological features may play a preeminent role in the genesis, as well as in the maintenance of "gonalgia sine materia", thus confirming previous data available in medical literature.     

Erratum: Neurofibromatosis type 1 (NF1): Identification of eight unreported mutations in NF1 gene in Italian patients

In the original version of this article, the title was incorrect. Please find the correct title given here. The publisher deeply regrets this error. The original article to which this Erratum refers was published in Human Mutation 22:179–180 Human Mutation(2003) 22(2) 179–180     

Trisomy 8 in myelodysplasia and acute leukemia is constitutional in 15-20% of cases.

The trisomy 8 found in malignancies may derive from a constitutional trisomy 8 mosaicism (CT8M), and in these cases the trisomy itself may be regarded as the first mutation in a multistep carcinogenetic process. To assess the frequency of CT8M in hematological dysplastic and neoplastic disorders with trisomy 8, an informative sample of 14 patients was collected. The data ascertained included chromosome analyses of fibroblast cultures and of PHA-stimulated blood cultures in patients with normal blood differential count, as well as possible CT8M clinical signs. One patient showed trisomy 8 in all cell types analyzed and undoubtedly has a CT8M; a second patient consistently showed trisomy 8 in PHA-stimulated blood cultures when no immature myeloid cells were present in blood and should be considered as having CT8M; a third patient, with Philadelphia-positive chronic myelocytic leukemia, was more difficult to interpret, but the possibility that she had CT8M is likely. A few clinical signs of CT8M were also present in these three patients. Our data indicate that the frequency of CT8M in hematological dysplastic and neoplastic disorders with trisomy 8 is approximately 15-20%.