Lipofuscin in the corpus luteum of macaque ovaries

The present study examined the histochemistry of pigments in the corpus luteum of the ovaries of cynomolgus monkeys (Macaca fascicularis), Japanese monkeys (Macaca fuscata), and rhesus monkeys (Macaca mulatta). Yellowish brown pigments were found in the regressing corpus luteum cells. Histochemical studies revealed that these pigments consisted of lipofuscin, the so-called age pigment. The findings obtained suggest that accumulation of lipofuscin might be related to cellular aging of the corpus luteum.     

Identification of a novel member of yeast mitochondrial Hsp70-associated motor and chaperone proteins that facilitates protein translocation across the inner membrane

Here, we report the identification of yeast 15-kD Tim15/Zim17, a new member of mitochondrial Hsp70 (mtHsp70)-associated motor and chaperone (MMC) proteins. The 15-kD MMC protein is a peripheral inner membrane protein with a zinc-finger motif. Depletion of the 15-kD protein led to impaired import of presequence-containing proteins into the matrix in vivo and in vitro. Overexpression of the 15-kD protein rescued the functional defects of mtHsp70 in ssc1-3 cells, and a fusion protein containing the 15-kD protein physically interacts with purified mtHsp70. Tim15/Zim17 therefore cooperates with mtHsp70 to facilitate import of presequence-containing proteins into the matrix.     

The phosphate carrier has an ability to be sorted to either the TIM22 pathway or the TIM23 pathway for its import into yeast mitochondria

Most mitochondrial proteins are synthesized in the cytosol, imported into mitochondria via the TOM40 (translocase of the mitochondrial outer membrane 40) complex, and follow several distinct sorting pathways to reach their destination submitochondrial compartments. Phosphate carrier (PiC) is an inner membrane protein with 6 transmembrane segments (TM1-TM6) and requires, after translocation across the outer membrane, the Tim9-Tim10 complex and the TIM22 complex to be inserted into the inner membrane. Here we analyzed an in vitro import of fusion proteins between various PiC segments and mouse dihydrofolate reductase. The fusion protein without TM1 and TM2 was translocated across the outer membrane but was not inserted into the inner membrane. The fusion proteins without TM1-TM4 were not inserted into the inner membrane but instead translocated across the inner membrane. Functional defects of Tim50 of the TIM23 complex caused either by depletion of the protein or the addition of anti-Tim50 antibodies blocked translocation of the fusion proteins without TM1-TM4 across the inner membrane, suggesting that lack of TM1-TM4 led to switch of its sorting pathway from the TIM22 pathway to the TIM23 pathway. PiC thus appears to have a latent signal for sorting to the TIM23 pathway, which is exposed by reduced interactions with the Tim9-Tim10 complex and maintenance of the import competence.     

The Polo-like kinase Plx1 interacts with and inhibits Myt1 after fertilization of Xenopus eggs

During the meiotic cell cycle in Xenopus oocytes, p90(rsk), the downstream kinase of the Mos-MAPK pathway, interacts with and inhibits the Cdc2 inhibitory kinase Myt1. However, p90(rsk) is inactivated after fertilization due to the degradation of Mos. Here we show that the Polo-like kinase Plx1, instead of p90(rsk), interacts with and inhibits Myt1 after fertilization of Xenopus eggs. At the M phase of the embryonic cell cycle, Cdc2 phosphorylates Myt1 on Thr478 and thereby creates a docking site for Plx1. Plx1 can phosphorylate Myt1 and inhibit its kinase activity both in vitro and in vivo. The interaction between Myt1 and Plx1 is required, at least in part, for normal embryonic cell divisions. Finally, and interestingly, Myt1 is phosphorylated on Thr478 even during the meiotic cell cycle, but its interaction with Plx1 is largely inhibited by p90(rsk)-mediated phosphorylation. These results indicate a switchover in the Myt1 inhibition mechanism at fertilization of Xenopus eggs, and strongly suggest that Plx1 acts as a direct inhibitory kinase of Myt1 in the mitotic cell cycles in Xenopus.     

Stimulation of host NKT cells by synthetic glycolipid regulates acute graft-versus-host disease by inducing Th2 polarization of donor T cells

NKT cells are a unique immunoregulatory T cell population that produces large amounts of cytokines. We have investigated whether stimulation of host NKT cells could modulate acute graft-vs-host disease (GVHD) in mice. Injection of the synthetic NKT cell ligand alpha-galactosylceramide (alpha-GalCer) to recipient mice on day 0 following allogeneic bone marrow transplantation promoted Th2 polarization of donor T cells and a dramatic reduction of serum TNF-alpha, a critical mediator of GVHD. A single injection of alpha-GalCer to recipient mice significantly reduced morbidity and mortality of GVHD. However, the same treatment was unable to confer protection against GVHD in NKT cell-deficient CD1d knockout (CD1d(-/-)) or IL-4(-/-) recipient mice or when STAT6(-/-) mice were used as donors, indicating the critical role of host NKT cells, host production of IL-4, and Th2 cytokine responses mediated by donor T cells on the protective effects of alpha-GalCer against GVHD. Thus, stimulation of host NKT cells through administration of NKT ligand can regulate acute GVHD by inducing Th2 polarization of donor T cells via STAT6-dependent mechanisms and might represent a novel strategy for prevention of acute GVHD.     

Predicting invasion in mammographically detected microcalcifcation: a preliminary report

Background

Malignant pleural mesothelioma is a rare malignancy. The outcome remains poor despite complete surgical resection.

Patients and methods

Eleven patients with histologicaly proven epithelial type malignant pleural mesothelioma undergoing extrapleural pneumonectomy with systemic chemotherapy and/or radiotherapy before and after surgical resection were retrospectively reviewed.

Results

Ten out of 11 patients underwent complete surgical resection, of these 7 patients had stage I disease. Of these 7 patients, 5 are alive without any recurrence, a 2-year survival rate of 80% was observed in this group. There was no operative mortality or morbidity.

Conclusion

Extrapleural pneumonectomy with perioperative adjuvant treatment is safe and effective procedure for epithelial type malignant pleural mesothelioma.     

Mode of competition for light and water amongst juvenile beech and spruce trees under ambient and elevated levels of O3 and CO2

Key message

Our study provides evidence that neither elevated CO ₂ nor elevated O ₃ alters the positive asymmetric competition for light and the symmetric competition for water among beech and spruce individuals grown in monoculture. We conclude that the mechanism of competition (i.e. symmetric/asymmetric) above (e.g shading or overtopping effect) and belowground (e.g. non-preemption or foraging) rather than abiotic treatments such as elevated CO ₂ , O ₃ and CO ₂ /O ₃ regimes, plays a dominant role for ensuring competitive success among tree saplings.

Abstract

Despite numerous studies conducted on plant responses to increasing CO₂ and O₃ concentrations, there is still a gap in understanding on how these gasses would affect the mode of competition (e.g., the ability by which larger and smaller plants capture resources) at the individual level of intra-specific beech and spruce saplings. Using empirical data and simulations from the plant-growth model PLATHO, we analyzed underlying mechanisms of competition and extrapolated effects beyond the time span of the experiment. We hypothesized that among juvenile beech and spruce trees planted in monoculture, +CO₂ would diminish the positive asymmetric competition for light. Conversely, +O₃ would enhance this outcome. In addition, we hypothesized that the symmetric mode of competition belowground for water would remain unchanged, irrespective of +CO₂ and/or +O₃ treatments. Our results showed that +CO₂ and/or +O₃ treatments did not alter the mode of competition aboveground for light. Conversely, we accepted our hypothesis that the mode of competition for water would remain unchanged under both treatments. Overall, we conclude that neither +CO₂ nor +O₃ alters the positive asymmetric competition for light and the symmetric competition for water among beech and spruce individuals grown in monoculture. We further conclude that competitive mechanism above (e.g., shading or overtopping effect) and belowground (e.g., non-preemption or foraging) rather than abiotic treatments, such as elevated CO₂, O₃ and CO₂/O₃ regimes, plays a dominant role for ensuring competitive success among tree saplings.