Impact of Method of Preparation of Amorphous Solid Dispersions on Mechanical Properties: Comparison of Coprecipitation and Spray Drying

Usage of the amorphous phase of compounds has become the method of choice to overcome oral bioavailability problems related to poor solubility. Due to the unstable nature of glasses, it is clear that the method of preparation of the amorphous glass will have an impact on physical/chemical stability and in turn in vivo performance. The method of preparation can also have a profound impact on the mechanical properties of the amorphous phase. We have explored the impact of preparation method on the mechanical properties of an amorphous solid dispersion using a development compound, GDC-0810. Three methods were used to generate amorphous solid dispersions (ASDs) of 50% GDC-0810 with hydroxypropyl methylcellulose acetate succinate: (1) spray drying, (2) coprecipitation using overhead mixing, and (3) coprecipitation using resonant acoustic mixing. All 3 methods were found to generate ASDs with good phase mixing and similar glass transition temperatures. Coprecipitated ASD powders (overhead mixing and resonant acoustic mixing) demonstrated superior tabletability and flow properties when compared to the spray drying powder. Careful choice of manufacturing process can be used to tune material properties of ASDs to make them more amenable for downstream operations like tableting. Acoustic mixing has been demonstrated as a scalable new method to make ASDs through coprecipitation.     

Genomic donor cassette sharing during VLRA and VLRC assembly in jawless vertebrates

Lampreys possess two T-like lymphocyte lineages that express either variable lymphocyte receptor (VLR) A or VLRC antigen receptors. VLRA⁺ and VLRC⁺ lymphocytes share many similarities with the two principal T-cell lineages of jawed vertebrates expressing the αβ and γδ T-cell receptors (TCRs). During the assembly of VLR genes, several types of genomic cassettes are inserted, in step-wise fashion, into incomplete germ-line genes to generate the mature forms of antigen receptor genes. Unexpectedly, the structurally variable components of VLRA and VLRC receptors often possess partially identical sequences; this phenomenon of module sharing between these two VLR isotypes occurs in both lampreys and hagfishes. By contrast, VLRA and VLRC molecules typically do not share their building blocks with the structurally analogous VLRB receptors that are expressed by B-like lymphocytes. Our studies reveal that VLRA and VLRC germ-line genes are situated in close proximity to each other in the lamprey genome and indicate the interspersed arrangement of isotype-specific and shared genomic donor cassettes; these features may facilitate the shared cassette use. The genomic structure of the VLRA/VLRC locus in lampreys is reminiscent of the interspersed nature of the TCRA/TCRD locus in jawed vertebrates that also allows the sharing of some variable gene segments during the recombinatorial assembly of TCR genes.The only two extant taxa of jawless vertebrates (agnatha), lampreys and hagfishes, occupy a unique position in chordate phylogeny and thus are a focal point for studies in comparative immunology. Although jawless vertebrates were shown to reject skin allografts and to produce serum agglutinins to mammalian red blood cells and bacteria (1, 2), the cellular and molecular bases for these adaptive responses remained elusive until the recent identification of their alternative adaptive immune system (3). In contrast to the antigen receptors of jawed vertebrates, whose structural framework is the Ig-domain, the basic building block of agnathan antigen receptors is the leucine-rich repeat (LRR) (4–6). In analogy to the situation in jawed vertebrates, mature genes of so-called variable lymphocyte receptors (VLRs) are combinatorially assembled from different types of genomic donor LRR cassettes; their sequences are inserted into incomplete germ-line VLR genes (4–6). A gene conversion-like process is postulated to underlie the VLR gene assembly (7, 8), through the activity of orthologs of mammalian activation-induced cytidine deaminase (AID), termed cytidine deaminases 1 and 2 (CDA1 and CDA2) (7, 9). As is the case for T-cell receptors (TCRs) and B-cell receptors (BCRs) of jawed vertebrates, combinatorial VLR assembly generates vast repertoires of diverse anticipatory receptors (4–6).Three VLR genes, VLRA, VLRB and VLRC, have been identified in lampreys and hagfishes (3, 9–12). The three VLR isotypes are differentially expressed by three distinct populations of lymphocytes in lampreys (9, 13). The two types of T-like cells of lamprey, VLRA⁺ and VLRC⁺ lymphocytes, are generated in the thymoid, a lymphoepithelial tissue equivalent to the thymus (13–15); this situation is analogous to the development in the thymus of the two distinct αβ and γδ T-cell lineages in jawed vertebrates. The VLRB⁺ cells appear to be generated in hematopoietic tissues outside of the thymoid (14), much like B cells in jawed vertebrates. These findings suggest that these basic pathways of lymphocyte differentiation already existed in a common ancestor of jawed and jawless vertebrates (4–6, 16).The close developmental relationship of the two principal lineages of T lymphocytes in jawed vertebrates is reflected in the unique genomic organization of the TCR genes that encode the four chains of the two different heterodimeric αβ and γδ TCRs (17). Here, we examine the sequence diversity and genomic organization of VLRA and VLRC receptor genes to gain insight into their functional and evolutionary relationship.     

Gynaecomastia correction: A review of our experience

Introduction:

Gynaecomastia is a common problem in the male population with a reported prevalence of up to 36%. Various treatment techniques have been described but none have gained universal acceptance. We reviewed all gynaecomastia patients operated on by one consultant over a 7-year period to assess the morbidity and complication rates associated with the procedure.

Materials and Methods:

Clinical notes and outpatient records of all patients who underwent gynaecomastia correction at University Hospital North Staffordshire between 01/10/2001 to 01/10/2009 were retrospectively reviewed. A modified version of the Breast Evaluation Questionnaire was used to assess patients satisfaction with the procedure.

Results:

Twenty-nine patients and a total of 53 breasts were operated on during the study period. Patients underwent either liposuction alone (6 breasts - 11.3%), excision alone (37 breasts - 69.8%) or both excision and liposuction (10 breasts - 18.9%). Twelve operated breasts (22.6%) experienced some form of complication. Minor complications included seroma (2 patients), superficial wound dehiscence (2 patients) and minor bleeding not requiring theatre (3 patients). Two patients developed haematomas requiring evacuation in theatre. No cases of wound infection, major wound dehiscence or revision surgery were encountered. Twenty-six patients (89.7%) returned the patient satisfaction questionnaire. Patients scored an average 4.12 with regards comfort of their chest in different settings, 3.98 with regards chest appearance in different settings, and 4.22 with regards satisfaction levels for themselves and their partner/family. Overall complication rate was 22.6%. Grade III patients experienced the highest complication rate (35.7%), followed by grade II (22.7%) and grade I (17.6%). Overall complication rates among the excision only group was the highest (29.8%) followed by the liposuction only group (16.7%) and the liposuction and excision group (10.0%). There were high satisfaction rates amongst both patients and surgeon. Eleven patients (37.9%) had their outcome classified as ‘excellent’ by the operating surgeon, 16 patients (55.2%) as ‘good’, 1 (3.4%) as ‘satisfactory’ and 1(3.4%) as ‘poor’.

Conclusion:

Gynaecomastia is a complex condition which poses a significant challenge to the plastic surgeon. Despite the possible complications our case series demonstrates that outcomes of operative correction can be favourable and yield high levels of satisfaction from both patient and surgeon.KEY WORDS: Plastic Surgery, University Hospital North Staffordshire, Correction, gynaecomastia, surgery     

Validation of the Maryland Aggregate Pathology Index (MAPI), a pre‐implantation scoring system that predicts graft outcome

Predicting graft outcome after renal transplantation based on donor histological features has remained elusive and is subject to institutional variability. We have shown in a retrospective study that the Maryland Aggregate Pathology Index score reliably predicts graft outcome. We sought to validate the scoring system in our center and a second transplant center. We analyzed 140 deceased donor kidneys pre‐implantation biopsies from center 1 and 65 from center 2. The patients had a mean follow‐up of 695 ± 424 and 656 ± 305 d respectively. Although MAPI scores were similar, there were significant differences in donor and recipient parameters between both centers. Despite this, MAPI was predictive of graft outcome for both centers by Cox univariate, multivariate and time dependent ROC analysis. For center 1 and 2, three yr graft survival within each MAPI group was statistically equivalent. The three‐yr graft survival at center 1 for low, intermediate, and high MAPI groups were 84.3%, 56.5%, and 50.0%, respectively, p ≤ 0.0001, and at center 2 were 83.3%, 33.3%, and 33.3%, p = 0.006. MAPI, which is based on a pre‐implantation biopsy, demonstrated similar predictive and outcome results from both centers. As expanded criteria donors (ECD) criteria have redefined marginal kidneys, MAPI has the potential to further define ECD kidneys, increase utilization, and ultimately improve outcomes.     

2-Phenylindole and Arylsulphonamide: Novel Scaffolds Bactericidal against Mycobacterium tuberculosis

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Breast vibro-acoustography: initial experience in benign lesions

Background

Functional magnetic resonance imaging (fMRI) analysis is commonly done with cross-correlation analysis (CCA) and the General Linear Model (GLM). Both CCA and GLM techniques, however, typically perform calculations on a per-voxel basis and do not consider relationships neighboring voxels may have. Clustered voxel analyses have then been developed to improve fMRI signal detections by taking advantages of relationships of neighboring voxels. Mean-shift clustering (MSC) is another technique which takes into account properties of neighboring voxels and can be considered for enhancing fMRI activation detection.

Methods

This study examines the adoption of MSC to fMRI analysis. MSC was applied to a Statistical Parameter Image generated with the CCA technique on both simulated and real fMRI data. The MSC technique was then compared with CCA and CCA plus cluster analysis. A range of kernel sizes were used to examine how the technique behaves.

Results

Receiver Operating Characteristic curves shows an improvement over CCA and Cluster analysis. False positive rates are lower with the proposed technique. MSC allows the use of a low intensity threshold and also does not require the use of a cluster size threshold, which improves detection of weak activations and highly focused activations.

Conclusion

The proposed technique shows improved activation detection for both simulated and real Blood Oxygen Level Dependent fMRI data. More detailed studies are required to further develop the proposed technique.     

Balloon‐occluded retrograde transvenous obliteration for recurrent fundal gastric variceal bleeding in an adolescent

Gastric variceal bleeding is associated with high morbidity and mortality. Balloon‐occluded retrograde transvenous obliteration is a relatively new treatment used to control bleeding gastric varices that involves transvenous sclerosis of gastric varices through a spontaneous gastrorenal shunt. Here, we report on a 14‐yr‐old patient that underwent balloon‐occluded retrograde transvenous obliteration for refractory bleeding fundal varices in the setting of esophageal varices and cirrhosis, which did not respond to medical management or endoscopic injection. This case report serves as a reminder that balloon‐occluded retrograde transvenous obliteration can successfully control fundal variceal bleeding in pediatric patients and may serve as a bridge to liver transplantation.