Bone morphogenetic protein- and mating-dependent secretory cell growth and migration in the Drosophila accessory gland

The paired male accessory glands of Drosophila melanogaster enhance sperm function, stimulate egg production, and reduce female receptivity to other males by releasing a complex mixture of glycoproteins from a secretory epithelium into seminal fluid. A small subpopulation of about 40 specialized secretory cells, called secondary cells, resides at the distal tip of each gland. We show that these cells grow via mechanisms promoted by mating. If aging males mate repeatedly, a subset of these cells delaminates from and migrates along the apical surface of the glandular epithelium toward the proximal end of the gland. Remarkably, these secretory cells can transfer to females with sperm during mating. The frequency of this event increases with age, so that more than 50% of triple-mated, 18-d-old males transfer secondary cells to females. Bone morphogenetic protein signaling specifically in secondary cells is needed to drive all of these processes and is required for the accessory gland to produce its normal effects on female postmating behavior in multiply mated males. We conclude that secondary cells are secretory cells with unusual migratory properties that can allow them to be transferred to females, and that these properties are a consequence of signaling that is required for secondary cells to maintain their normal reproductive functions as males age and mate.     

The effect of calcium ion concentration on the bone response to oxidized titanium implants

Aim: To investigate the effect of calcium concentration on the bone tissue response to Ca‐incorporated titanium implants Materials and methods: Two titanium surfaces containing 4.2% and 6.6% calcium were prepared using the micro‐arc oxidation process. The implants were inserted in the tibia of nine New Zealand White rabbits. After 6 weeks of healing, the bone response to the implants was quantitatively compared by biomechanical and histomorphometrical measurements. Results: Ca 4.2% and Ca 6.6% containing implants revealed no distinctive differences in their qualitative surface chemistry; chemical bonding state of Ca in titanium oxide was mainly calcium titanates. No significant differences were observed between two implants in peak removal torque and shear strength comparisons (P>0.05). Histomorphometrical analyses presented no significant differences in bone–metal contact, bone area and newly formed bone measurements between two implants (P>0.05). Conclusions: From biomechanical and histomorphometrical measurements, the two calcium concentrations in this study did not differ significantly with respect to their influence on the bone tissue response. This similar bone response in rabbit tibiae may be explained by the similarity of the qualitative Ca chemistry in titanium surfaces.     

99mTc-thymine scintigraphy may be a promising method in the diagnosis of breast cancer

OBJECTIVE:

Mammography has been established as the gold standard for the detection of breast cancer, and imaging techniques such as ultrasonography, magnetic resonance imaging, scintigraphy and positron emission tomography may be useful to improve its sensitivity and specificity. The objective of this study with breast scintigraphy was to evaluate the uptake of 99mTc-thymine in mammary lesions.

METHODS:

A total of 45 patients were included in this study. Thirty-three patients (73%) were subjected to surgery or percutaneous biopsy, providing histopathological data. The other 12 patients who remained under surveillance received clinical examinations and biannual mammography with a normal follow-up of at least three years, the data from which were used for comparison with the scintimammography results.

RESULTS:

The majority of patients (64.4%) had clinically impalpable lesions with a mammogram diagnosis of microcalcifications, impalpable nodules, or focal asymmetry. Of the studied lesions, 87% were smaller or equal to 20 mm in diameter, and 22% had malignant histopathological findings. Scintigraphy with 99mTc-thymine had a sensitivity of 70%, a specificity of 85.7%, positive and negative predictive values of 58.3% and 90.9%, respectively, and an accuracy of 82.2%.

CONCLUSIONS:

The results of this study are consistent with those previously reported by other authors. The good specificity and high negative predictive value of this technique and the absence of uptake in the heart indicate that it may be a promising complementary method in clinical practice and that it may contribute to reducing unnecessary benign biopsies.     

Catechol‐O‐methyltransferase gene val158met polymorphism and depressive symptoms during early childhood

Catechol‐O‐Methyltransferase (COMT) is a critical regulator of catecholamine levels in the brain. A functional polymorphism of the COMT gene, val158met, has been linked to internalizing symptoms (i.e., depression and anxiety) in adolescents and adults. We extended this research by investigating whether the val158met polymorphism was associated with childhood symptoms of depression and anxiety in two independent samples of young children (Ns = 476 and 409). In both samples, preschool‐aged children were genotyped for the COMT val158met polymorphism. Symptoms of psychopathology were assessed via parent interviews and primary caregiver reports. In both samples, children homozygous for the val allele had higher levels of depressive symptoms compared to children with at least one copy of the met allele. Our findings extend previous research in older participants by showing links between the COMT val158met polymorphism and internalizing symptoms in early childhood. © 2013 Wiley Periodicals, Inc.     

Characterisation of bone following ultrasonic cutting

Objectives

Ultrasonic surgery is an increasingly popular technique for cutting bone, but little research has investigated how the ultrasonic tip oscillations may affect the cuts they produce in bone. The aim of this investigation was to evaluate the oscillation and cutting characteristics of an ultrasonic surgical device.

Materials and methods

A Piezosurgery 3 (Mectron, Carasco, Italy) ultrasonic cutting system was utilised with an OP3 style tip. The system was operated with the tip in contact with porcine bone samples (loads of 50 to 200 g) mounted at 45° to the vertical insert tip and with a water flow of 57 ml/min. Tip oscillation amplitude was determined using scanning laser vibrometry. Bone surfaces defects were characterised using laser profilometry and scanning electron microscopy.

Results

A positive relationship was observed between the magnitude of tip oscillations and the dimensions of defects cut into the bone surface. Overloading the tip led to a reduction in oscillation and hence in the defect produced. A contact load of 150 g provided the greatest depth of cut. Defects produced in the bone came from two clear phases of cutting.

Conclusions

The structure of the bone was found to be an important factor in the cut characteristics following piezosurgery.

Clinical relevance

Cutting of bone with ultrasonics is influenced by the load applied and the setting used. Care must be used to prevent the tip from sliding over the bone at low loadings.     

Synthetic non-classical luminescence generation by enhanced silica nanophotonics based on nano-bio-FRET

Fluorescent silica nanoparticles (NPs–(SiO₂–Fluo)) were synthesized based on the classical Störber method for cyanobacteria labelling. Modified mono-coloured SiO₂ NPs with fluorescein (Fl) and rhodamine B (RhB) were obtained (NPs–(SiO₂–Fl) and NPs–(SiO₂–RhB)). Moreover, multi-coloured SiO₂ NPs, via the incorporation of both emitters (NPs–(SiO₂–RhB–Fl)), were tuned for optimal emissions and the biodetection of cyanobacteria. NPs–(SiO₂–Fl) and NPs–(SiO₂–RhB–Fl) were optimized for detection via laser fluorescence microscopy and in-flow cytometry with laser excitation and fluorescence detection. By TEM, homogeneous SiO₂ NPs of 180.0 nm in diameter were recorded. These sizes were slightly increased due to the covalent linking incorporation of fluorescent dye emitters to 210.0 nm with mono-coloured fluorescent modified amine-organosilanes, and to 340.0 nm in diameter with multi-coloured dye incorporation. NPs–(SiO₂–Fluo) showed variable emission depending on the dye emitter concentration, quantum yield and applied luminescent pathway. Thus, mono-coloured NPs–(SiO₂–Fl) and NPs–(SiO₂–RhB) showed diminished emissions in comparison to multi-coloured NPs–(SiO₂–RhB–Fl). This enhancement was explained by fluorescence resonance energy transfer (FRET) between Fl as a fluorescent energy donor and RhB as an energy acceptor produced within the nanoarchitecture, produced only in the presence of both fluorophores with the appropriate laser excitation of the energy donor. The depositions of the nano-emitters on cyanobacteria by non-covalent interactions were observed by TEM and laser fluorescence microscopy. For multi-coloured NPs–(SiO₂–RhB–Fl) labelling, bio-FRET was observed between the emission of the nano-labellers and the natural fluorophores from the cyanobacteria that quenched the emission of the whole nano-biostructure in comparison to mono-coloured NPs–(SiO₂–Fl) labelling. This fact was explained and discussed in terms of different fluorescence energy transfer from the nanolabellers towards different natural chromophore coupling. In the presence of NPs–(SiO₂–RhB–Fl) and NPs–(SiO₂–RhB), the emission was coupled with lower quantum yield chromophores; while upon the application of NPs–(SiO₂–Fl), it was coupled with higher quantum yield chromophores. In this manner, for enhanced luminescent nanoplatform tracking, the multi-coloured NPs–(SiO₂–RhB–Fl) showed improved properties; but more highly luminescent bio-surfaces were generated with mono-coloured NPs–(SiO₂–Fl) that permitted faster cyanobacteria detection and counting by laser fluorescence microscopy, and by in-flow cytometry with laser excitation and fluorescence detection.

Fluorescent silica nanophotonics for cyanobacteria labelling.