Vesicular release of prolactin from preformed prolactin granules is stimulated by soluble factor(s) from the anterior pituitary of lactating rats

This study demonstrates that conditioned media (CM) from the anterior pituitary gland (AP) of lactating rats contains soluble factors that promote in vitro prolactin (PRL) release from the pituitary glands of male rats. CM-induced PRL release was confirmed by polyacrylamide gel electrophoresis, ELISA and bioassay. In cultured AP cells challenged with CM, increased intracellular staining with the dye FM1-43 was observed, suggesting vesicular PRL release and subsequent endocytosis. The percentage and hormone content of PRL-containing cells but not of growth hormone-containing cells increased in cultured male AP cells when exposed to CM. When the release of PRL, prelabeled with [3H] leucine for 30 min to 24 h was examined, no stimulatory effect of CM was observed, suggesting that released PRL originates from hormone synthesized more than 24 h earlier. Accordingly, the PRL content of mature granules from male pituitary tissues decreased after CM treatment. These findings were confirmed by electron microscopy immunogold PRL labeling. Treatment with inhibitors of protein synthesis or vesicle trafficking between the endoplasmic reticulum and the Golgi complex did not prevent the stimulatory effect of CM on PRL release. However, blockage of traffic to the plasma membrane completely abolished the effect of CM. These results suggest that CM from the AP of lactators contains soluble factor(s) capable of inducing rapid vesicular release of PRL in the male AP, which originates from preformed, mature granules by mechanisms independent of protein synthesis.     

Multiple repeat caesarean deliveries: do they increase maternal and neonatal morbidity?

Objective: The aim of the present study is to evaluate the effects of the increased number of caesarean deliveries (CDs) in cases of multiple repeat caesarean deliveries (MRCDs) on maternal and neonatal morbidity.

Methods: MRCDs admitted to our hospital between January 2013 and September 2014 were analysed retrospectively. A total number of 1133 women were included in the study and were divided into 4 groups. Group 1: second CDs (n?=?329); Group 2: third CDs (n?=?225); Group 3: fourth CDs (n?=?447); Group 4: fifth CDs (n?=?132). The clinical, demographic, intraoperative and postoperative data of the patients were registered upon the review of patient files.

Results: The differences among the groups were found to be statistically significant in terms of mean maternal age, gravida, APGAR (Activity, Pulse, Grimace, Appearance, Respiration) scores, hospital stay and operation time. In addition, the difference was also statistically significant for severe adhesion, bladder injury and premature birth. No statistically significant difference was observed among the groups with respect to placenta previa, placenta accreta, caesarean hysterectomy, uterine scar rupture.

Conclusions: According to our findings, MRCDs seem to increasing the maternal and neonatal morbidity even though they are not life-threatening.     

Fetal anterior abdominal wall thickness may be an early ultrasonographic sign of gestational diabetes mellitus

Objective: The aim of the study was to investigate standard biometric measurements, such as biparietal diameter (BPD), femur length (FL), abdominal circumference (AC), estimated fetal weight (EFW) and anterior abdomen wall thickness (AAWT) in fetuses complicated by gestational diabetes mellitus (GDM) at the time of GDM screening, and to compare the results with healthy pregnant controls.

Methods: A total of 124 pregnant women between 26 and 28 weeks’ gestation were included in the study. These patients were divided into two groups based on their 75-g oral glucose tolerance test results. The study group consisted of 55 pregnant women with GDM, and 69 healthy pregnant women constituted our control group.

Results: The study groups did not differ with respect to the mean BPD, FL, AC and EFW; however, the mean AAWT was significantly higher in the GDM group, 4.07?±?0.46 mm versus 3.28?±?0.37 mm in the control group (p < 0.001).

Conclusions: The only fetal sonographic measurement found to significantly differ between the study groups was the AAWT in 26 weeks at the time of gestational diabetes screening, suggesting that measuring the AAWT may have a role in the evaluation of fetal growth in pregnancies complicated by gestational diabetes.     

Early weight bearing of porous HA/TCP (60/40) ceramics in vivo: a longitudinal study in a segmental bone defect model of rabbit

Porous interconnected hydroxyapatite (HA) and HA/tricalcium phosphate (TCP) (60/40) ceramics are promising materials for hard tissue repair. However, the mechanical properties of these materials have not been accurately determined under weight-bearing conditions. In this study, newly developed HA and HA/TCP (60/40) ceramics were used with intramedullary fixation in segmental bone defects of rabbits. Early radiological, histological, densitometric and biomechanical changes were evaluated. The mean radiological grade of healing and bonding to bone was higher in HA/TCP (60/40) ceramics than that of pure HA ceramics but the difference was not statistically significant. The densities of both implanted ceramics improved with time, supported by the histological evaluation of bone matrix ingrowth into ceramic pores, whereas the densities at the bone–ceramic interface decreased gradually. Flexural resonant frequencies and three-point bending strength increased, revealing an increase in mechanical stability during this early critical time interval where implant and/or bone–implant interface failures occur frequently. It can be concluded that both HA and HA/TCP (60/40) ceramics have a limited application in the treatment of load-bearing segmental bone defects but did not fail at the early stages of implantation.     

Neuraminidase produces a decrease of adherence of slime-forming <Emphasis Type="Italic">Staphylococcus aureus</Emphasis> to gelatin-impregnated polyester fiber graft fabric: an experimental study

Because slime-forming microorganisms are the major causative agents of graft infections, we aimed to investigate bacterial adherence in slime-forming and nonslime-forming Staphylococcus aureus and to determine the role of neuraminidase (NANase) on adherence to gelatin-impregnated polyester fiber graft fabric. An in vitro model was developed to quantitatively measure bacterial adherence to the surface of the graft. The grafts were divided into two groups – those colonized with slime-forming S. aureus and those colonized with nonslime-forming S. aureus. The grafts were put into sterile tubes and human plasma was instilled and incubated at 37°C to perform fibrin deposition on the grafts. After 48 h of incubation, grafts were drained and inoculated with slime-forming or nonslime-forming S. aureus in triptic soy broth in the presence or absence of NANase. Following 36 h of incubation at 36°C, grafts were vortexed and cultured to perform a colony count. Bacterial counts were expressed as total colony-forming units per square centimeter of graft. Slime-forming S. aureus had greater affinity with the graft compared with nonslime-forming S. aureus (P < 0.05). The adherence of slime-forming S. aureus was impaired by NANase treatment (P < 0.001) but NANase treatment of nonslime-forming S. aureus did not change the adherence to the graft (P > 0.05). These results show that slime plays an important role in the pathogenesis of vascular graft infection. Adherence of slime-forming S. aureus can be decreased by NANase treatment. This may have implications for the development of neuraminidase-embedded vascular grafts to diminish biomaterial-related infections.     

Pineal gland calcification, lumbar intervertebral disc degeneration and abdominal aorta calcifying atherosclerosis correlate in low back pain subjects: A cross-sectional observational CT study

The goal of this cross-sectional observational study was to assess the possible impact of pineal gland calcification upon the intervertebral disc degeneration and abdominal aorta atherosclerosis in subjects with low back pain, and to investigate the course of these processes with aging. The study was carried out on 81 (66 women and 15 men) subjects: younger than 45 years (group X, n = 22), 45–65 years of age (group Y, n = 45), and older than 65 years (group Z, n = 14). In addition to clinical data, computed tomography (CT) scan of the brain as well as X-ray and CT examination of the lumbar spine were recorded in this study. The degree of disc degeneration and calcification rates of aortic wall and pineal gland were independently determined by two radiologists. Both ratio of calcified pineal gland and density of pineal calcification increased progressively with aging. Also, both the degree of aortic wall calcification and disc degeneration score increased with advancing age. On CT scan, a positive correlation between degree of aortic wall calcification and disc degeneration score was found (r = 0.306, p < 0.01). Importantly, there was a positive association between calcification of the pineal gland and degenerative disc disease in X-ray or CT study (r = 0.378 and r = 0.295, p < 0.005 and p < 0.01, respectively), as well as between abdominal aorta atherosclerosis and pineal calcification (r = 0.634, p < 0.001). Our findings suggest that there is a significant interaction between pineal gland calcification and lumbar intervertebral disc degeneration and also abdominal aorta atherosclerosis. However, further studies with a larger subject cohorts are needed.     

Vascular endothelial growth factor receptor 3 directly regulates murine neurogenesis

Neural stem cells (NSCs) are slowly dividing astrocytes that are intimately associated with capillary endothelial cells in the subventricular zone (SVZ) of the brain. Functionally, members of the vascular endothelial growth factor (VEGF) family can stimulate neurogenesis as well as angiogenesis, but it has been unclear whether they act directly via VEGF receptors (VEGFRs) expressed by neural cells, or indirectly via the release of growth factors from angiogenic capillaries. Here, we show that VEGFR-3, a receptor required for lymphangiogenesis, is expressed by NSCs and is directly required for neurogenesis. Vegfr3:YFP reporter mice show VEGFR-3 expression in multipotent NSCs, which are capable of self-renewal and are activated by the VEGFR-3 ligand VEGF-C in vitro. Overexpression of VEGF-C stimulates VEGFR-3-expressing NSCs and neurogenesis in the SVZ without affecting angiogenesis. Conversely, conditional deletion of Vegfr3 in neural cells, inducible deletion in subventricular astrocytes, and blocking of VEGFR-3 signaling with antibodies reduce SVZ neurogenesis. Therefore, VEGF-C/VEGFR-3 signaling acts directly on NSCs and regulates adult neurogenesis, opening potential approaches for treatment of neurodegenerative diseases.