Ultrastructure of pig tubal ova

Summary The unfertilized ova of the pig are characterized by the first polar body situated in the perivitelline space. The metaphase chromosomes of the ova are found free in a cortical area, predominantly inhabited by the spindle fibers. Mitochondria show morphological changes in the form of swelling of their matrices. Frequently, the membranes of the individual cristae mitochondriales meet each other, forming meeting points, at regular intervals. The endoplasmic reticulum increases in quantity when compared with that of the pig follicular oocytes (Norberg, 1972b). The Golgi complexes are sparse and scattered. Occasionally, remnants of the end bulbs of the corona radiata cell processes occur below the surface membrane of the ova.Usually, the sperm-penetrated ova contain the first and the second polar body within the perivitelline space. Intranuclear annulate lamellae are observed within the male and female pronucleoplasm, and of particular interest are extended linear structures in one of the pronuclei. These structures may be considered as precursor stage in the formation of the intranuclear annulate lamellae. The parapronuclear cytoplasm is rich in organelles, especially the cytoplasmic annulate lamellae. In contrast to the scarcity of Golgi complexes in the unfertilized ova, many newly formed Golgi vesicles and lamellae reappear in the pronuclear stage. The zona pellucida displays ultrastructural changes following sperm penetration of the ova.This work was supported by the Agricultural Research Council of Norway.     

REEVALUATION OF THE NITROGEN FIXATION BEHAVIOR IN THE MARINE NON‐HETEROCYSTOUS CYANOBACTERIUM LYNGBYA MAJUSCULA1

Lyngbya majuscula Harvey ex Gomont is a common marine cyanobacterium in tropical and subtropical near‐shore waters. A few reports have indicated that L. majuscula fixes nitrogen only in the light. Because this feature is uncommon among non‐heterocystous cyanobacteria, we attempted a reevaluation. Nitrogenase activity, regulation, and localization were examined over diel cycles on natural populations of L. majuscula growing in subtidal zones off Zanzibar in the western Indian Ocean. The data show that L. majuscula fixed nitrogen and synthesized nitrogenase in all cells during the dark phase of a diel cycle. During the light phase, nitrogenase was degraded to undetectable levels.     

Studies on the antibacterial effects of statins--in vitro and in vivo

Background

Statin treatment has been associated with a beneficial outcome on respiratory tract infections. In addition, previous in vitro and in vivo experiments have indicated favorable effects of statins in bacterial infections.

Aim

The aim of the present study was to elucidate possible antibacterial effects of statins against primary pathogens of the respiratory tract.

Methods

MIC-values for simvastatin, fluvastatin and pravastatin against S. pneumoniae, M. catarrhalis and H. influenzae were determined by traditional antibacterial assays. A BioScreen instrument was used to monitor effects of statins on bacterial growth and to assess possible synergistic effects with penicillin. Bacterial growth in whole blood and serum from healthy volunteers before and after a single dose of simvastatin, fluvastatin and penicillin (positive control) was determined using a blood culture system (BactAlert).

Findings

The MIC-value for simvastatin against S pneumoniae and M catarrhalis was 15 µg/mL (36 mmol/L). Fluvastatin and Pravastatin showed no antibacterial effect in concentrations up to 100 µg/mL (230 µmol/L). Statins did not affect growth or viability of H influenzae. Single doses of statins given to healthy volunteers did not affect growth of pneumococci, whereas penicillin efficiently killed all bacteria.

Conclusions

Simvastatin at high concentrations 15 µg/mL (36 µmol/L) rapidly kills S pneumoniae and M catarrhalis. However, these concentrations by far exceed the concentrations detected in human blood during simvastatin therapy (1–15 nmol/L) and single doses of statins given to healthy volunteers did not improve antibacterial effects of whole blood. Thus, a direct bactericidal effect of statins in vivo is probably not the mechanism behind the observed beneficial effect of statins against various infections.     

Postnatal deficiency of essential fatty acids in mice results in resistance to diet-induced obesity and low plasma insulin during adulthood

Our objective was to investigate the long-term metabolic effects of postnatal essential fatty acid deficiency (EFAD). Mouse dams were fed an EFAD diet or an isoenergetic control diet 4 days before delivery and throughout lactation. The pups were weaned to standard diet (STD) and were later subdivided into two groups: receiving high fat diet (HFD) or STD. Body composition, energy expenditure, food intake and leptin levels were analyzed in adult offspring. Blood glucose and plasma insulin concentrations were measured before and during a glucose tolerance test. EFAD offspring fed STD were leaner with lower plasma leptin and insulin concentrations compared to controls. EFAD offspring fed HFD were resistant to diet-induced obesity, had higher energy expenditure and lower levels of plasma leptin and insulin compared to controls. These results indicate that the fatty acid composition during lactation is important for body composition and glucose tolerance in the adult offspring.     

Climate‐induced warming imposes a threat to north European spring ecosystems

Interest in climate change effects on groundwater has increased dramatically during the last decade. The mechanisms of climate‐related groundwater depletion have been thoroughly reviewed, but the influence of global warming on groundwater‐dependent ecosystems (GDEs) remains poorly known. Here we report long‐term water temperature trends in 66 northern European cold‐water springs. A vast majority of the springs (82%) exhibited a significant increase in water temperature during 1968–2012. Mean spring water temperatures were closely related to regional air temperature and global radiative forcing of the corresponding year. Based on three alternative climate scenarios representing low (RCP2.6), intermediate (RCP6) and high‐emission scenarios (RCP8.5), we estimate that increase in mean spring water temperature in the region is likely to range from 0.67 °C (RCP2.6) to 5.94 °C (RCP8.5) by 2086. According to the worst‐case scenario, water temperature of these originally cold‐water ecosystems (regional mean in the late 1970s: 4.7 °C) may exceed 12 °C by the end of this century. We used bryophyte and macroinvertebrate species data from Finnish springs and spring‐fed streams to assess ecological impacts of the predicted warming. An increase in spring water temperature by several degrees will likely have substantial biodiversity impacts, causing regional extinction of native, cold‐stenothermal spring specialists, whereas species diversity of headwater generalists is likely to increase. Even a slight (by 1 °C) increase in water temperature may eliminate endemic spring species, thus altering bryophyte and macroinvertebrate assemblages of spring‐fed streams. Climate change‐induced warming of northern regions may thus alter species composition of the spring biota and cause regional homogenization of biodiversity in headwater ecosystems.     

Assay of tramadol in urine by capillary electrophoresis using laser-induced native fluorescence detection

Capillary electrophoresis (CE) with UV laser-induced native fluorescence detection was developed as a sensitive and selective assay for the direct determination of tramadol in human urine without extraction or preconcentration. The main problem in CE is the small inner diameter of the capillary which causes a low sensitivity with instruments equipped with a UV detector. Laser-induced native fluorescence with a frequency doubled argon ion laser at an excitation wavelength of 257 nm was used for the direct assay of tramadol in urine to enhance the limit of detection about 1000-fold compared to UV absorption detection. The detection system consists of an imaging spectrograph and an intensified CCD camera, which views an illuminated 1.5 mm section of the capillary. This set-up is able to record the whole emission spectra of the analytes to achieve additionally wavelength-resolved electropherograms. In the concentration range of 20 ng/ml–5 μg/ml in human urine coefficients of correlation were better than 0.998. Within-day variation determined on four different concentrations showed accuracies ranging from 90.2 to 108.4%. The relative standard deviation (RSD) was determined to be less than 10%. Day-to-day variation presented accuracies ranging from 90.9 to 103.1% with an RSD less than 8%.     

mRNA expression and localization of bNOS,eNOS and iNOS in human cervix at preterm and term labour

Background  

Preterm birth is the primary cause of the neonatal mortality and morbidity. There will be no preterm birth without a cervical softening. Nitric oxide (NO) is shown to be a mediator of term cervical ripening. The aim of this study was to investigate mRNA expression of the three isomers of NO synthases (NOS) and to identify them by immunohistochemistry in the human cervix at preterm birth compared to term.     

BCG Skin Infection Triggers IL-1R-MyD88-Dependent Migration of EpCAMlow CD11bhigh Skin Dendritic cells to Draining Lymph Node During CD4+ T-Cell Priming

The transport of antigen from the periphery to the draining lymph node (DLN) is critical for T-cell priming but remains poorly studied during infection with Mycobacterium bovis Bacille Calmette-Guérin (BCG). To address this we employed a mouse model to track the traffic of Dendritic cells (DCs) and mycobacteria from the BCG inoculation site in the skin to the DLN. Detection of BCG in the DLN was concomitant with the priming of antigen-specific CD4⁺ T cells at that site. We found EpCAM^low CD11b^high migratory skin DCs to be mobilized during the transport of BCG to the DLN. Migratory skin DCs distributed to the T-cell area of the LN, co-localized with BCG and were found in close apposition to antigen-specific CD4⁺ T cells. Consequently, blockade of skin DC traffic into DLN dramatically reduced mycobacterial entry into DLN and muted T-cell priming. Interestingly, DC and mycobacterial entry into the DLN was dependent on IL-1R-I, MyD88, TNFR-I and IL-12p40. In addition, we found using DC adoptive transfers that the requirement for MyD88 in BCG-triggered migration was not restricted to the migrating DC itself and that hematopoietic expression of MyD88 was needed in part for full-fledged migration. Our observations thus identify a population of DCs that contribute towards the priming of CD4⁺ T cells to BCG infection by transporting bacilli into the DLN in an IL-1R-MyD88-dependent manner and reveal both DC-intrinsic and -extrinsic requirements for MyD88 in DC migration.     

Views of Swedish Commissioning Parents Relating to the Exploitation Discourse in Using Transnational Surrogacy

Transnational surrogacy, when people travel abroad for reproduction with the help of a surrogate mother, is a heavily debated phenomenon. One of the most salient discourses on surrogacy is the one affirming that Westerners, in their quest for having a child, exploit poor women in countries such as India. As surrogacy within the Swedish health care system is not permitted, Swedish commissioning parents have used transnational surrogacy, and the majority has turned to India. This interview study aimed to explore how commissioning parents negotiate the present discourses on surrogacy. Findings from the study suggest that the commissioning parents’ views on using surrogacy are influenced by competing discourses on surrogacy represented by media and surrogacy agencies. The use of this reproductive method resulted, then, in some ambiguity. Although commissioning parents defy the exploitation discourse by referring to what they have learnt about the surrogate mother’s life situation and by pointing at the significant benefits for her, they still had a request for regulation of surrogacy in Sweden, to better protect all parties involved. This study, then, gives a complex view on surrogacy, where the commissioning parents simultaneously argue against the exploitation discourse but at the same time are uncertain if the surrogate mothers are well protected in the surrogacy arrangements. Their responses to the situation endorse the need for regulation both in Sweden and India.