In vitro incubation of golden (syrian) hamster ovarian oocytes and human sperm with a human oviduct specific glycoprotein

The objective of this study was to determine if human oviduct specific glycoprotein (huOGP) would associate with hamster ovarian oocytes and human sperm during in vitro incubation. The huOGP used in these studies was partially purified from human hydrosalpinx fluid. Hamster ovarian oocytes and human sperm samples were incubated in culture medium with and without huOGP. Association of huOGP was assessed by indirect immunofluorescence assay using a polyclonal antibody prepared against huOGP. Intense fluorescence of the zona pellucida, and bright but uneven fluorescence of the perivitelline space, were observed in hamster ovarian oocytes following incubation in the presence of huOGP. A similar but more uniform pattern of fluorescence was observed when hamster oviductal oocytes (positive controls) were incubated in culture medium alone. Fluorescence was absent when oocytes were assayed with preimmune serum. The association of huOGP with the zona pellucida and perivitelline space appeared to be specific since thyroglobulin, a large molecular weight glycoprotein, and human serum albumin, the major protein in oviduct fluid, did not associate with the hamster oocytes nor inhibit huOGP association when included in the culture medium. Fluorescence was absent when human sperm incubated with huOGP were assayed with antiserum to huOGP. However, human sperm fluoresced when incubated with a uterine glycoprotein, CUPED, which had previously been shown to bind to cat sperm during in vitro incubation. Sperm also fluoresced brightly when human sperm antibody was used as a positive control. Solubilization of sperm membrane proteins postincubation and analysis of these proteins by 1-D SDS-PAGE followed by immunoblotting also failed to show an association of huOGP with human sperm. Electron microscopy of sperm both pre- and postsolubilization confirmed that the sperm membranes were removed by this process. In conclusion, the association of huOGP with hamster oocytes in vitro suggests that huOGP may associate with human oocytes in vivo, whereas that may not be true for human sperm in vivo. The association of huOGP with oocytes may serve to facilitate the process of fertilization and early embryonic development within the oviduct. © 1994 Wiley-Liss, Inc.     

“Ik kan mijn acceptgiro niet meer invullen”

Visual problems occur frequently in elderly patients and are often caused by ophthalmological problems. In this clinical lesson we show that visual problems can also be caused by posterior cortical atrophy (PCA). PCA is a clinico-radiological syndrome that is often caused by Alzheimer’s disease and other neurodegenerative diseases as Lewy body dementia and corticobasal degeneration. It is characterized by progressive decline in visual information processing. In addition, there is relative retention of memory and language in early stages. Brain imaging shows atrophy of the posterior brain areas.     

A basal membrane-like structure surrounding tumour nodules may prevent intraepithelial leucocyte infiltration in colorectal cancer

Epithelial tumours consist of an epithelial compartment and a stromal compartment, which are sometimes separated by a basal membrane-like structure. We sought to determine whether these factors have prognostic value in 84 curatively resected stage II and III colorectal cancer by immunohistochemically staining tumours for leucocytes (CD45) and extracellular matrix, and to assess the presence of a basal membrane-like structure. Leucocyte infiltration was also assessed in hematoxylin-eosin (HE) stained sections. Most leucocytes were located in the tumour stroma. A relatively high intraepithelial leucocyte infiltration was significantly correlated with a lower level of tumour recurrence (P=0.03) and a longer disease-free survival (P=0.05), whereas leucocytes located in the tumour stroma (P=0.92) or at the advancing margin (p=0.06) were not. Intraepithelial leucocyte infiltration was also significantly correlated with leucocyte infiltration in the tumour stroma (P=0.02) and at the advancing tumour margin (P=0.005), and as assessed in HE-stained tumour sections (P=0.05), but each of these parameters on its own did not have a prognostic value in predicting disease-free survival. Moreover, the presence of a basal membrane-like structure surrounding the tumour epithelium was inversely correlated with the number of intraepithelial leucocytes (P=0.05), suggesting that this membrane-like structure functions as a barrier to intraepithelial leucocyte infiltration. We conclude that leucocytes must be in the direct vicinity of tumour cells to affect tumour growth. The presence of an extracellular matrix barrier seems to prevent this interaction.     

Exposure of neural crest cells to elevated glucose leads to congenital heart defects, an effect that can be prevented by N-acetylcysteine

BACKGROUND: Diabetes mellitus during pregnancy increases the risk for congenital heart disease in the offspring. The majority of the cardiovascular malformations occur in the outflow tract and pharyngeal arch arteries, where neural crest cells are essential for normal development. We studied the effects of specific exposure of neural crest cells to elevated glucose on heart development. Antioxidants reduce the damaging effect of glucose on neural crest cells in vitro; therefore, we investigated the effect of supplementing N-acetylcysteine in vivo. METHODS: Cardiac neural crest of HH 8-12 chicken embryos was directly exposed by a single injection in the neural tube with 30 mM D-glucose (or 30 mM L-glucose as a control). To examine the effect of a reduction in oxidative stress, we added 2 mM N-acetylcysteine to the injected D-glucose. RESULTS: Exposure of neural crest cells to elevated D-glucose-induced congenital heart malformations in 82% of the embryos. In the embryos injected with L-glucose, only 9% developed a heart malformation. As expected, all malformations were located in the outflow tract and pharyngeal arch arteries. The frequency of heart malformations decreased from 82% to 27% when 2 mM N-acetylcysteine was added to the injected D-glucose. CONCLUSIONS: These data are the first to confirm that the vulnerability of neural crest cells to elevated glucose induces congenital heart malformations. The fact that N-acetylcysteine limits the teratogenicity of glucose implies that its damaging effect is mediated by an increase of oxidative stress in the neural crest cells.     

Nucleotide-binding oligomerization domain-2 modulates specific TLR pathways for the induction of cytokine release

The recognition of peptidoglycan by cells of the innate immune system has been controversial; both TLR2 and nucleotide-binding oligomerization domain-2 (NOD2) have been implicated in this process. In the present study we demonstrate that although NOD2 is required for recognition of peptidoglycan, this leads to strong synergistic effects on TLR2-mediated production of both pro- and anti-inflammatory cytokines. Defective IL-10 production in patients with Crohn's disease bearing loss of function mutations of NOD2 may lead to overwhelming inflammation due to a subsequent Th1 bias. In addition to the potentiation of TLR2 effects, NOD2 is a modulator of signals transmitted through TLR4 and TLR3, but not through TLR5, TLR9, or TLR7. Thus, interaction between NOD2 and specific TLR pathways may represent an important modulatory mechanism of innate immune responses.     

Preventive action of organosilicon treatments against disfigurement of wood under laboratory and outdoor conditions

Organosilicons and biocides with known effectiveness against fungal disfigurement were used for dipping or impregnating Scots pine sapwood specimens. All specimens were artificially or naturally weathered and the colour of all specimens was determined with a spectrophotometer at fixed times. After artificial weathering the specimens were used in blue stain tests according to EN 152 or according to the EN 152 reverse method. The naturally exposed specimens were inspected for fungal disfigurement on their back side. Although the results learn that the coating approach is far better than the wood preservatives approach for evaluating blue stain attack of organosilicon-treated wood, organosilicons fail to protect wood under laboratory conditions. Outdoor exposure, however, revealed that organosilicon impregnated specimens were better protected against fungal disfigurement. The addition of a biocide improves the performance. Artificially aged specimens did not show significant colour differences compared to untreated Scots pine sapwood, while naturally aged specimens did, depending on the treatment conditions and presence of biocides. Organosilicons are able to reduce leaching of (degraded) wood constituents, leading to fewer colour changes compared to untreated scots pine and to decreased availability of nutrients for superficial fungal growth.