Identification of a novel UTY-encoded minor histocompatibility antigen.

Minor histocompatibility antigens (mHags) encoded by the Y-chromosome (H-Y-mHags) are known to play a pivotal role in allogeneic haematopoietic cell transplantation (HCT) involving female donors and male recipients. We present a new H-Y-mHag, YYNAFHWAI (UTY(139-147)), encoded by the UTY gene and presented by HLA-A*24:02. Briefly, short peptide stretches encompassing multiple putative H-Y-mHags were designed using a bioinformatics predictor of peptide-HLA binding, NetMHCpan. These peptides were used to screen for peptide-specific HLA-restricted T cell responses in peripheral blood mononuclear cells obtained post-HCT from male recipients of female donor grafts. In one of these recipients, a CD8+ T cell response was observed against a peptide stretch encoded by the UTY gene. Another bioinformatics tool, HLArestrictor, was used to identify the optimal peptide and HLA-restriction element. Using peptide/HLA tetramers, the specificity of the CD8+ T cell response was successfully validated as being HLA-A*24:02-restricted and directed against the male UTY(139-147) peptide. Functional analysis of these T cells demonstrated male UTY(139-147) peptide-specific cytokine secretion (IFNγ, TNFα and MIP-1ß) and cytotoxic degranulation (CD107a). In contrast, no responses were seen when the T cells were stimulated with patient tumour cells alone. CD8+ T cells specific for this new H-Y-mHag were found in three of five HLA-A*24:02-positive male recipients of female donor HCT grafts available for this study.

Determination of intracellular trehalose and glycogen in Saccharomyces cerevisiae.

A simple, sensitive and nonlaborious enzyme-based method has been developed for determination of both trehalose and glycogen in yeast cells. The method is based on extraction of trehalose and glycogen into a 40 mM acetate buffer (pH 4.8) by mechanical disintegration of the cells in a bead mill. Subsequently, trehalose and glycogen can be hydrolyzed to glucose by the enzymes trehalase and amyloglycosidase, respectively. The formed glucose is quantified by a flow injection analyzer based on the enzyme glucose oxidase. The method gives results comparable to traditional methods but the simplicity of the analysis results in a much lower relative standard deviation. The excellent sensitivity of the glucose analyzer means that as little as 1 microgram trehalose or glycogen can be determined which reduces the required sample volume. This makes the method ideal for physiological studies, e.g., of transients in continuous cultures of Saccharomyces cerevisiae. In addition, a consistent procedure has been derived for pretreatment and storage of samples.

Silencing MIG1 in Saccharomyces cerevisiae: effects of antisense MIG1 expression and MIG1 gene disruption.

Silencing of MIG1, a transcription factor imposing carbon catabolite repression on invertase, was attempted, either by disrupting the gene or by expressing antisense copies of the gene. The performance of the recombinant strains in bioreactor batch cultivations on sucrose, in the presence of glucose, was compared with that of the wild-type strain under the same conditions. In the delta migI strain, the rate of sucrose utilization was independent (10 mmol/g/h) of the glucose concentration. During the cultivations with the wild-type strain and the antisense strains, two distinct phases were observed. The rates of sucrose hydrolysis were < 1 mmol/g/h and 9 to 10 mmol/g/h in the first and second phases, respectively. Entry into the second cultivation phase was characterized by a decline in glucose concentration below 12 mmol/liter. As expected, disruption of MIG1 resulted in a relief of glucose repression. However, silencing of MIG1 expression was not achieved by expressing antisense MIG1, even though antisense MIG1 RNA was sufficiently stable to be detected. In the wild-type and delta migI strains, the specific growth rate was 0.32 to 0.33 h-1, whereas it was lower in the antisense strains, 0.25 to 0.30 h-1.

Acardiac fetus in a triplet pregnancy.

The acardiac monster represents one of the most severe but rare congenital anomalies. It occurs only in multiple gestations associated with vascular anastomoses between the affected fetus and its co-twin. The prenatal diagnosis of an acardiac fetus must be suspected in any multiple gestation in which cardiac activity cannot be documented sonographically in a growing fetus. We report an acardiac fetus occurring in a spontaneously conceived triplet pregnancy. A review of the literature, including pathogenetic theories and sonographic reports, is discussed.

Successful management of fetal cervical teratoma using the EXIT procedure.

Fetal cervical teratoma is a cause of polyhydramnios, premature labor, and newborn airway obstruction. Formation of a multispecialty team and use of the EXIT procedure is essential for survival of the neonate. Without a team, there is little hope for fetal survival; mortality will be 80-100%. Early diagnosis and planning are essential. Cervical teratomas can contribute to pulmonary insufficiency and chondromalacia because of a mass effect in utero and underdevelopment of the fetal lungs.