Melosis in holocentric chromosomes: Kinetic activity is randomly restricted to the chromatid ends of sex univalents inGraphosoma italicum (Heteroptera)

We have determined the number and location of the nucleolar organizing regions in spermatocytes ofGraphosoma italicum (2n=12A+ XY/XX) by means of silver impregnation, chromomycin A₃/distamycin A staining and fluorescencein situ hybridization. The identification of only one nucleolar organizing region located at one of the X chromosome ends has provided a suitable cytological marker to analyse the segregation of this univalent and that of the XY pseudobivalent during the first and second meiotic divisions respectively. Our results clearly show that at first meiotic metaphase the chromatids of the X chromosome are orientated with their long axes perpendicular to the polar axis. Although the kinetic activity is restricted to only one end in both X chromatids during the first meiotic division, both ends of the same chromatid have the same probability of showing such kinetic activity. In this sense, we also report that the chromatid segregation maybe initiated either at the same sister chromatid ends or at opposite ends in each chromatid. Thus, this indicates a sex chromatid independence as regards to the chromatid segregation during the first meiotic division. Throughout the second meiotic division both ends of the X chromatid are involved with the same probability in the end-to-end association to conform the XY pseudobivalent. This also implies a random localization of the kinetic activity at the ends opposite to those involved in the end-to-end association.accepted for publication by J. S. (Pat) Heslop-Harrison     

Squash Procedure for Protein Immunolocalization in Meiotic Cells

Several techniques have been developed for protein immunolocalization in meiotic cells. However, most of them include treatments that lead to cell disruption and are only suitable for prophase-I cells. We describe a novel squash procedure of cell preparation for protein immunolabelling of different meiotic stages. This procedure is an alternative to both cryosectioning and whole spreading procedures. We present results obtained in mouse spermatocytes with three different antibodies: the MPM-2 mAb against mitotic phosphoepitopes, an anticentromere serum and a polyclonal serum against the SCP3 protein of the axial elements and lateral elements of the synaptonemal complex. The procedure was tested for single and double immunolabelling. With this technique a large number of cells at different meiotic stages can be analysed. Cell stages are easily identified and cell and chromosome structures are preserved. Thus, it allows the study of chromosome behaviour and the relations hips between the different structural elements of the cell throughout meiotic divisions. Our procedure is also suitable for three-dimensional (3D) analyses and proved to be reliable in a wide range of systems including insects and mammals. In addition, the procedure may be interesting to obtain a rapid immunological diagnosis.     

Teaching Case Ciliated Renal Tubular Cells in Crescentic Glomerulonephritis

Numerous cilia were found in the proximal convoluted tubules from a case of crescentic glomerulonephritis. The cilia exhibited the 9 + 2 pattern of organization characteristic of motile cilia. Microvilli were scanty or absent in heavily ciliated cells. The significance of renal cilia is discussed.     

Supravital staining: It's role in detecting early malignancies

The efficacy of supravital staining in the detection of malignancies in oro and oropharyngeal lesions and its role in the detection of malignant changes in premalignant lesions were studied. This prospective study comprises 90 cases of clinically suspicious lesions and it was done over a period of 3 years. Most of the patients had multiple risk factors for the development of malignancy. All underwent staining with a modified solution of 1% toluidine blue (TB). In our study the overall sensitivity was 97.29% and the specificity was 62.5%.     

Flowering in bursting bubbles with viscoelastic interfaces

The lifetime of bubbles, from formation to rupture, attracts attention because bubbles are often present in natural and industrial processes, and their geometry, drainage, coarsening, and rupture strongly affect those operations. Bubble rupture happens rapidly, and it may generate a cascade of small droplets or bubbles. Once a hole is nucleated within a bubble, it opens up with a variety of shapes and velocities depending on the liquid properties. A range of bubble rupture modes are reported in literature in which the reduction of a surface energy drives the rupture against inertial and viscous forces. The role of surface viscoelasticity of the liquid film in this colorful scenario is, however, still unknown. We found that the presence of interfacial viscoelasticity has a profound effect in the bubble bursting dynamics. Indeed, we observed different bubble bursting mechanisms upon the transition from viscous-controlled to surface viscoelasticity-controlled rupture. When this transition occurs, a bursting bubble resembling the blooming of a flower is observed. A simple modeling argument is proposed, leading to the prediction of the characteristic length scales and the number and shape of the bubble flower petals, thus paving the way for the control of liquid formulations with surface viscoelasticity as a key ingredient. These findings can have important implications in the study of bubble dynamics, with consequences for the numerous processes involving bubble rupture. Bubble flowering can indeed impact phenomena such as the spreading of nutrients in nature or the life of cells in bioreactors.

When residing in Newtonian fluids, bubble rupture proceeds with features that are shown in Fig. 1. Different dynamics are observed depending on the capillary number, Ca=u η/γ, where u is the experimentally measured characteristic retraction speed of the film, η is the liquid viscosity, and γ is the surface tension between the liquid and gas, and the Reynolds number, Re=ρuRbubble/η, where ρ is the liquid density, and Rbubble is the bubble radius (1–7). Fig. 1 A–D report observed bubble ruptures in the different regimes previously discussed in the literature: 1) for Re≪1, viscous forces are larger than inertial and surface forces, resulting in a very slow hole opening (8) (Fig. 1A); 2) when Re>1, the hole opens up much more quickly (9), and a toroidal rim (Fig. 1B) is subjected to an azimuthal instability, which leads to fingering and, possibly, jetting (Fig. 1 B–D), depending on the corresponding Ca value. If Ca≫1, the rim is stable and folds upward (10); otherwise, inertial instabilities break it into pieces with a characteristic length scale, d=Rbubbleh, where h is the film thickness (11).Open in a separate windowFig. 1.Bubble bursting dynamics. (A) Low Re. (B and C) High Ca and high Re. (D) Low Ca and high Re. (E) Low Ca and high Re with intermediate interfacial viscoelasticity (20 mg/mL of BSA). (F) Low Ca and high Re with high interfacial viscoelasticity (50 mg/mL of BSA). (G) Bubble rupture as functions of time for different concentrations of BSA. Increasing the concentration of BSA leads to an increase in the surface viscoelasticity, and the bubble bursting dynamics change. The concentration of 20 mg/mL is identified as the limit above which flowering occurs. The number of petals, 10 at 20 mg/mL, decreases to 5 when the concentration of BSA is increased to 50 mg/mL. The bursting time (from the puncture to complete film retraction) increases when BSA is added, and it changes from 1.5 ms at 0.1 mg/mL to 2.7 ms at 50 mg/mL.Here, we report evidence of the effect of surface viscoelasticity in bubble rupture dynamics. Surface viscoelasticity is adjusted by adding a surface-active material to the bulk and modulating its concentration and chemistry. We chose bovine serum albumin (BSA) proteins (12, 13), as they are known to form highly viscoelastic surface layers. At low concentrations, BSA molecules are adsorbed at the air/water interface with their major axis parallel to the surface. No protein denaturation occurs, and the molecules retain their globular conformation. As the concentration of BSA increases, a primary monolayer achieves full surface coverage, and a secondary monolayer appears, extending into the aqueous phase (14, 15). Adsorbed protein molecules are connected by interprotein contacts forming an interconnected network within the adsorbed layers (16). Upon compression, globular proteins, such as BSA, respond as deformable spheres, thereby being capable of storing elastic energy (yielding high storage moduli) (17). Many examples can be found in the literature in which the addition of surfactants to the protein solution can drastically change surface properties, giving an unlimited variety of model systems to achieve desired surface properties with a straightforward tuning of the surfactant concentration (18).     

The utilization of psychopharmacological treatment and medication adherence among Medicaid enrolled children and adolescents with bipolar depression

Background

To examine the psychotropic medication utilization and compare adherence to treatment regimens in pediatric bipolar depression patients.

Methods

2003–2007 MAX data from four geographically diverse states were used. According to the regimen received by the patients (6–18 years) in the first month after the index bipolar depression diagnosis, patients were categorized into six mutually exclusive groups. The month to month change of treatment regimen in each group was then assessed during the 6 month post-index bipolar depression diagnosis. Adherence to each regimen was measured as continuation of the initial regimen, switch to a new regimen, augmentation with medication from a different therapeutic category, and discontinuation of all pharmacotherapies. Repeated measure analysis was conducted to compare the trend of each adherence measure across the study groups.

Results

Of the 5,460 subjects identified, 15.39% received antipsychotic monotherapy, 9.43% received mood stabilizer monotherapy, 5.77% received antidepressant monotherapy, 26.48% received mood stabilizer–antipsychotic polytherapy, 22.51% received antidepressant polytherapy, and 19.89% received antipsychotic–mood stabilizer–antidepressant polytherapy. At the end of the follow-up period, over 50% of the 1st month polytherapy users and less than 50% of the monotherapy users were continuing their initial regimen. Repeated measure analysis using antipsychotic monotherapy as the reference group suggested differences in trend slopes (p<0.05).

Limitations

In absence of structured clinical evaluation, bipolar disorder diagnoses cannot be ascertained in this study.

Conclusions

Bipolar depression patients were predominantly treated with combinations of psychotropic drugs. Potentially questionable practice, such as antidepressant monotherapy was used only in a small fraction of patients. Combination regimens had better adherence as compared to monotherapies.     

Multidisciplinary management of hypohydrotic ectodermal dysplasia – a case report

Hypohydrotic ectodermal dysplasia is a hereditary disorder, which affects ectodermal derivatives. It manifests several abnormalities of the teeth, and is commonly inherited through female carriers. This case report presents a patient with compromised esthetics and function. A multidisciplinary approach was planned involving an oral pathologist, endodontist, orthodontist and a prosthodontist.