Perturbations in cortical development and neuronal network excitability arising from prenatal exposure to benzodiazepines in mice

During brain development, many factors influence the assembly and final positioning of cortical neurons, and this process is essential for proper circuit formation and normal brain function. Among many important extrinsic factors that guide the maturation of embryonic cortical neurons, the secreted neurotransmitter GABA has been proposed to influence both their migratory behaviour and their terminal differentiation. The full extent of the short‐term and long‐term changes in brain patterning and function caused by modulators of the GABA system is not known. In this study, we specifically investigated whether diazepam, a commonly used benzodiazepine that modulates the GABA_A receptor, alters neuronal positioning in vivo, and whether this can lead to lasting effects on brain function. We found that fetal exposure to diazepam did not change cell positioning within the embryonic day (E)14.5 mouse cerebral cortex, but significantly altered neuron positioning within the E18.5 cortex. In adult mice, diazepam treatment affected the distribution of cortical interneurons that express parvalbumin or calretinin, and also led to a decrease in the numbers of calretinin‐expressing interneurons. In addition, we observed that neonatal exposure to diazepam altered the sensitivity of mice to a proconvulsant challenge. Therefore, exposure of the fetal brain to benzodiazepines has consequences for the positioning of neurons and cortical network excitability.     

Unusual alleles of recB and recC stimulate excision of inverted repeat transposons Tn10 and Tn5.

Precise and nearly precise excision of transposon Tn10 occur by host-mediated processes unrelated to transposition. Both types of excision involve interactions between short (9 or 24 base-pair) direct repeat sequences at or near the termini of the transposon and are stimulated by the large (1,329-base-pair) inverted repeats that form the ends of Tn10. We describe here three mutations of Escherichia coli K-12, designated texA, that enhance excision of Tn10 and of the structurally analogous transposon Tn5. Genetic mapping and complementation analysis show that these mutations are unusual alleles of the recB and recC genes that alter but do not abolish RecBC function. As Tn10 excision normally does not depend on RecA or RecBC functions, texA mutations appear to provide another pathway for excision that depends on altered RecBC function; for one texA allele, excision has become dependent on RecA function as well. The available evidence suggests that texA mutations alter the stimulatory interaction between the inverted repeats of Tn10.     

Revision of Unicompartmental to Total Knee Arthroplasty: Does the Unicompartmental Implant (Metal-Backed vs All-Polyethylene) Impact the Total Knee Arthroplasty?

Background

The aim of this study is to investigate differences in implant requirement, outcomes, and re-revision when total knee arthroplasty (TKA) was performed following unicompartmental knee arthroplasties (UKAs) with metal-backed (MB) compared to all-polyethylene (AP) tibial components.

Predictive value of [<Superscript>18</Superscript>F]-fluoride PET for monitoring bone remodeling in patients with orthopedic conditions treated with a Taylor spatial frame

Purpose

The Taylor Spatial Frame (TSF) is used to correct orthopedic conditions such as correction osteotomies in delayed fracture healing and pseudarthrosis. Long-term TSF-treatments are common and may lead to complications. Current conventional radiological methods are often unsatisfactory for therapy monitoring. Hence, an imaging technique capable of quantifying bone healing progression would be advantageous.

Methods

A cohort of 24 patients with different orthopedic conditions, pseudarthrosis (n?=?10), deformities subjected to correction osteotomy (n?=?9), and fracture (n?=?5) underwent dynamic [¹⁸F]-fluoride (Na¹⁸F) PET/CT at 8 weeks and 4 months, respectively, after application of a TSF. Parametric images, corresponding to the net transport rate of [¹⁸F]-fluoride from plasma to bone, K _i were calculated. The ratio of the maximum K _i at PET scan 2 and 1 (\( {\overline{K}}_{i, \max } \)) as well as the ratio of the maximum Standard Uptake Value at PET scan 2 and 1 (\( {\overline{SUV}}_{\max } \)) were calculated for each individual. Different treatment end-points were scored, and the overall treatment outcome score was compared with the osteoblastic activity progression as scored with \( {\overline{K}}_{i, \max } \) or \( {\overline{SUV}}_{\max } \).

Results

\( {\overline{K}}_{i, \max } \) and \( {\overline{SUV}}_{\max } \) were not correlated within each orthopedic group (p?>?0.1 for all groups), nor for the pooled population (p?=?0.12). The distribution of \( {\overline{K}}_{i, \max } \) was found significantly different among the different orthopedic groups (p?=?0.0046) -also for \( {\overline{SUV}}_{\max } \) (p?=?0.022). The positive and negative treatment predictive values for \( {\overline{K}}_{i, \max } \) were 66.7 % and 77.8 %, respectively. Corresponding values for \( {\overline{SUV}}_{\max } \) were 25 % and 33.3 %

Conclusions

The \( {\overline{K}}_{i, \max } \) obtained from dynamic [¹⁸F]-fluoride-PET imaging is a promising predictive factor to evaluate changes in bone healing in response to TSF treatment.

     

The limited effectiveness of legislation against female genital mutilation and the role of community beliefs in Upper East Region,Ghana

Female genital mutilation (FGM) has long been practised in many communities in the Upper East Region of Ghana. Although the Ghanaian state has a long tradition of supporting women's rights, it has not been successful in eradicating FGM, despite a law against the practice in an amendment to the Criminal Code in 1994 and the Domestic Violence Act 2003. This qualitative study in the Upper East Region examined the role of the state in stopping the practice of FGM through legal means, and why FGM continues to be practised in the community. In-depth interviews were conducted with six state officials, a circumciser, the president of a women's advocacy organisation, and semi-structured interviews with 32 community members. Although FGM has been criminalised, political support to ensure that the law is effectively implemented has been lacking. FGM education and eradication must be given more priority and significant funding by the Ghanaian state. For interventions to be effective, legal measures need to be combined with social measures. Communities practising FGM must be involved in the planning and implementation of anti-FGM interventions. Successful eradication of the practice is possible if education and dialogue between state institutions, gender and human rights groups and practising communities is strengthened.     

The phosphoinositide-specific phospholipase C inhibitor U73122 (1-(6-((17beta-3-methoxyestra-1,3,5(10)-trien-17-yl)amino)hexyl)-1H-pyrrole-2,5-dione) spontaneously forms conjugates with common components of cell culture medium.

Phosphoinositide-specific phospholipase C (PLC) is a key enzyme in the regulation of Ca(2+) release from inositol 1,4,5-triphosphate-sensitive stores. U73122 (1-(6-((17beta-3-methoxyestra-1,3,5(10)-trien-17-yl)amino)hexyl)-1H-pyrrole-2,5-dione) has been extensively used as a pharmacological inhibitor of PLC to elucidate the importance of this enzyme family in signal transduction pathways. U73122 has an electrophilic maleimide group, which readily reacts with nucleophiles such as thiols and amines. In the current study the conjugation of U73122 to common components of cell culture medium, namely l-glutamine, glutathione, and bovine serum albumin (BSA), was demonstrated. The half-life of U73122 on incubation with phosphate-buffered saline (PBS), Hanks' buffered saline solution (with 2 mM glutamine), optimized basal nutrient medium (MCDB131, without BSA), complete medium, Dulbecco's modified Eagle's medium (with 2 mM l-glutamine) was approximately 150, 60, 32, 30, and 18 min, respectively. However, U73122 was not recoverable from medium supplemented with 0.5% BSA. U73122 underwent hydrolysis of the maleimide group when incubated with PBS. Glutamine conjugates of U73122 were identified in cell culture medium. Furthermore, the inhibition of epidermal growth factor-stimulated Ca(2+) release in a human epidermoid carcinoma cell line (A431) by U73122 was substantially reduced by the presence of BSA in a time-dependent manner. In complex cellular assays, the availability of U73122 to inhibit PLC may be limited by its chemical reactivity and lead to the misinterpretation of results in pharmacological assays.     

Distribution of some Gal beta 1-3(4)GlcNAc related carbohydrate antigens on the mouse uterine epithelium in relation to the peri-implantational period

Using monoclonal antibodies of defined carbohydrate specificity we have looked at the distribution of various Gal beta 1-3(4)GlcNAc related oligosaccharide determinants in the mouse uterus during the first 6 days of pregnancy. Frozen sections of uterus from B6D2F1, B6CBF1 or B6D2F1/BOM female mice were incubated with the monoclonal antibodies and then with a fluorescein isothiocyanate conjugate of goat anti-mouse IgM and viewed by epifluorescence illumination. None of the antibodies bound specifically to stroma cells but antibodies recognising difucosylated Gal beta 1-3(4)GlcNAc structures, the monofucosylated type II determinant (SSEA-1) and an H type I oligosaccharide bound to cells of the uterine luminal epithelium and glands and to the uterine secretions. Antibodies recognising the three different types of saccharide showed independent changes in staining intensity during early pregnancy. The antibody which recognises H type I structures (667/9E9) showed a change in distribution from binding to most cells of the uterine epithelium in the non-pregnant mouse and on day 3 of pregnancy to binding restricted to areas of epithelial cells interspersed with non-staining clumps of cells between days 4 and 5 of pregnancy.     

Origin and distribution of capsaicin-sensitive substance P-immunoreactive nerves in the nasal mucosa

In immunohistochemical studies, substance P-immunoreactivity (SP-IR) was found in a population of trigeminal ganglion cells in guinea pig, rat and cat. SP-IR nerve endings were found in the spinal trigeminal nucleus, around sphenopalatine ganglion cells, around blood vessels, as well as under and within the epithelium of the nasal mucosa. Ligation and denervation experiments in the cat indicated that the SP-IR nerves in the sphenopalatine ganglion and the nasal mucosa are of trigeminal origin. Capsaicin pretreatment of guinea pigs and rats resulted in a selective loss of the SP-IR nerves in the nasal mucosa and sphenopalatine ganglion, while the parasympathetic and sympathetic nerves were still present.     

The importance of intraoperative angiographic findings for predicting long-term patency in coronary artery bypass operations

BACKGROUND: The quality of anastomosis is the cornerstone in coronary artery bypass operations. Intraoperative coronary angiography confirms graft patency with the possibility to revise graft failure. The aim of this study was to describe the lesions found at "on-table" angiography, and to evaluate the significance of these immediate angiographic findings for the long-term patency. METHODS: A total of 57 grafts (42 left internal mammary artery grafts and 15 saphenous vein grafts) in 45 patients who underwent off-pump coronary artery bypass operations were included. On-table angiography was carried out with fixed angiographic equipment installed in the operating room. Follow-up angiographies were performed at 3 months and at 12 months. RESULTS: The most frequent finding in an on-table angiogram was spasm, which was not present at follow-up. Out of nine kinks, only one developed into a significant stenosis at follow-up. Of 44 grafts that were normal on-table, 37 (84%) were normal at the follow-up. Of 11 grafts with significant lesions on-table, eight (73%) were normal at the follow-up. Five percent of the grafts were revised because of the on-table angiography. CONCLUSIONS: On-table angiograms can be occasionally difficult to interpret because not all findings are important for later patency. Optimal results on-table predict good long-term results with a negative predictive value of 0.84, whereas significant lesions on-table have less impact on the follow-up results because the positive predictive value was only 0.38.