The conundrum of olecranon aperture and its relation to the distal end of the humerus in a modern Indian population: An anatomical and surgical perspective.

PURPOSE: We aimed to clarify the morphology of the olecranon aperture (OA) of the humerus with its relationship to the distal end of the humerus (epicondylar width) and the width of the medullary canal. METHODS: In total, 156 dry adult humeri were examined for the presence of OA. When present, we reported their shape, measured transverse (TD) and vertical diameter (VD), the distance from its medial border to the tip of medial epicondyle (D1), lateral border to the tip of lateral epicondyle (D2) and lower border to the tip of trochlea (D3). The epicondylar width (EW) and the width of the medullary canal were also measured in all the humeri. RESULTS: OA was reported in 32 humeri (20.6%) with left side predominance, translucent septum in 35.8%, and opaque septum in 43.6%. The most typical shape noted was oval. On right side, mean VD and TD was 4.30±0.54mm and 5.85±0.45mm, respectively, whereas on left, these value were 4.21±0.56mm and 5.64±0.43mm, respectively. The mean of D1, D2 and D3 was 25.86±0.43mm, 26.50±0.28mm and 15.07±0.53mm on right and 24.80±0.41mm, 26.84±0.21mm and 15.81±0.31mm on left with significant difference (P<0.05). The medullary canal was significantly smaller in humeri with OA. CONCLUSION: Topographic location of OA may have possible role in determining safe zone for retrograde nailing in supracondylar humeral fractures. Since OA has a direct relation to the size of the intramedullary canal, it is crucial during preoperative planning and choosing an adequate surgical approach involving lower segment of humerus.

Strong interfacial Dzyaloshinskii-Moriya induced in Co due to contact with NiO.

The magnetic properties of NiO/Co/Pt as a function of Co layer thickness were investigated by polar magneto-optical Kerr effect (PMOKE) (magnetometry and microscopy) and Brillouin Light Scattering (BLS) spectroscopy. PMOKE measurements revealed strong surface anisotropy (1.8 mJ/m2) favoring perpendicular magnetic anisotropy and asymmetric domain wall propagation explained by anticlockwise chirality. BLS measurements show that this chirality is induced by strong interfacial Dzyaloshinskii-Moriya interaction (+ 2.0 pJ/m). This is one of the highest values reported so far for Co layers surrounded by different layers. The observed chirality is opposite to what has been found in Co/oxide interfaces. These results and data published earlier, indicate that the strength of interfacial Dzyaloshinskii-Moriya interaction increases with the amount of stoichiometric NiO. Therefore, this work shows that NiO is the source of the interfacial Dzyaloshinskii-Moriya interaction.

Synthesis and characterization of arabinoxylan-bis[2-(methacryloyloxy)ethyl] phosphate crosslinked copolymer network by high energy gamma radiation for use in controlled drug delivery applications.

Keeping in view the therapeutic important dietary fiber psyllium, herein this research report its potential has been explored for the formation of sterile hydrogel by high energy radiation induced copolymerization of arabinoxylan-poly bis[2-(methacryloyloxy)ethyl] phosphate (BMEP) for use as drug delivery carrier. The polymeric network structure was characterized by 13C NMR, FTIR, TGA/DTG and DSC, XRD and AFM techniques. Release profile of a drug cefuroxime and best fit kinetic model were determined. The blood -polymer interaction, mucosal-polymer adhesion, antioxidant and mechanical properties were also evaluated. The radiation dose influenced the crosslink density and the mesh size of the hydrogel network. Release profile of a drug cefuroxime followed non-Fickian diffusion and best fitted to first order kinetic model. The grafted product was sterile, porous, antioxidant and mucoadhesive in nature and could be explored for controlled and sustained GIT drug delivery applications.

Data-driven computer simulation of human cancer cell.

Using the Diagrammatic Cell Language trade mark, Gene Network Sciences (GNS) has created a network model of interconnected signal transduction pathways and gene expression networks that control human cell proliferation and apoptosis. It includes receptor activation and mitogenic signaling, initiation of cell cycle, and passage of checkpoints and apoptosis. Time-course experiments measuring mRNA abundance and protein activity are conducted on Caco-2 and HCT 116 colon cell lines. These data were used to constrain unknown regulatory interactions and kinetic parameters via sensitivity analysis and parameter optimization methods contained in the DigitalCell computer simulation platform. FACS, RNA knockdown, cell growth, and apoptosis data are also used to constrain the model and to identify unknown pathways, and cross talk between known pathways will also be discussed. Using the cell simulation, GNS tested the efficacy of various drug targets and performed validation experiments to test computer simulation predictions. The simulation is a powerful tool that can in principle incorporate patient-specific data on the DNA, RNA, and protein levels for assessing efficacy of therapeutics in specific patient populations and can greatly impact success of a given therapeutic strategy.

Clinicopathological study of pilomatricoma.

OBJECTIVE: To study the clinical and histopathologic spectrum of pilomatricoma, the benign tumor of hair matrix. METHODS: Retrospective review of 27 cases of pilomatricoma (Calcifying epithelioma of Malherbe) reported at Bahrain Defence Force Hospital from 1993-1999. RESULTS: Most of the cases were confused clinically with sebaceous cysts. Seventy eight per cent of the cases occurred below the age of 30 years. Female to male ratio was 5:4. Head, neck and upper limb were the most common sites for pilomatricoma. The size of the tumors ranged from between 4-35 mm in diameter. Tumors were encapsulated and solid composed of shadow and basophilic cells, and stroma containing varying amounts of calcification, ossification and inflammatory cells. CONCLUSION: Pilomatricomas have a wide variety of clinical characteristics and are often misdiagnosed with other skin conditions. They should be considered along with other benign and malignant conditions in the clinical differential diagnosis of solitary firm skin nodules especially those, which occur in the head, neck and upper limb.

Identification of oligomerizing peptides.

The AraC DNA binding domain is inactive in a monomeric form but can activate transcription from the arabinose operon promoters upon its dimerization. We used this property to identify plasmids encoding peptide additions to the AraC DNA binding domain that could dimerize the domain. We generated a high diversity library of plasmids by inserting 90-base oligonucleotides of random sequence ahead of DNA coding for the AraC DNA binding domain in an expression vector, transforming, and selecting colonies containing functional oligomeric peptide-AraC DNA binding domain chimeric proteins by their growth on minimal arabinose medium. Six of seven Ara(+) candidates were partially characterized, and one was purified. Equilibrium analytical centrifugation experiments showed that it dimerizes with a dissociation constant of approximately 2 micrometer.

Recognition of overlapping nucleotides by AraC and the sigma subunit of RNA polymerase.

The Escherichia coli promoter p(BAD), under the control of the AraC protein, drives the expression of mRNA encoding the AraB, AraA, and AraD gene products of the arabinose operon. The binding site of AraC at p(BAD) overlaps the RNA polymerase -35 recognition region by 4 bases, leaving 2 bases of the region not contacted by AraC. This overlap raises the question of whether AraC substitutes for the sigma subunit of RNA polymerase in recognition of the -35 region or whether both AraC and sigma make important contacts with the DNA in the -35 region. If sigma does not contact DNA near the -35 region, p(BAD) activity should be independent of the identity of the bases in the hexamer region that are not contacted by AraC. We have examined this issue in the p(BAD) promoter and in a second promoter where the AraC binding site overlaps the -35 region by only 2 bases. In both cases promoter activity is sensitive to changes in bases not contacted by AraC, showing that despite the overlap, sigma does read DNA in the -35 region. Since sigma and AraC are thus closely positioned at p(BAD), it is possible that AraC and sigma contact one another during transcription initiation. DNA migration retardation assays, however, showed that there exists only a slight degree of DNA binding cooperativity between AraC and sigma, thus suggesting either that the normal interactions between AraC and sigma are weak or that the presence of the entire RNA polymerase is necessary for significant interaction.

Cytocortical organization during natural and prolonged mitosis of mouse 8-cell blastomeres.

Late 8-cell blastomeres were harvested within the first 45 min after entering mitosis. Some mitotic cells were analysed within the ensuing 2 h for the organization of their surface in relation to their progress through mitosis. Whereas in most late interphase cells microvilli were restricted to a discrete polar region, in mitotic cells at all stages from early metaphase to immediately postcytokinesis microvilli were found to be present over more of the cell surface. Other mitotic cells were placed in nocodazole to arrest them in M-phase for up to 10 h. They were found to show an even more extensive distribution of microvilli over the whole surface, the longer periods of incubation yielding more extended coverage such that many cells no longer appeared to have any residual surface polarity. Removal from nocodazole at all time points from 1 to 10 h resulted in most cells completing mitosis to yield pairs of cells which, in most cases, resembled pairs derived from nonarrested blastomeres and in which a defined polar area of microvilli was restored. However, the percentage of differentiative divisions decreased after 6 h arrest. If, instead of removing cells from nocodazole, they were placed in both nocodazole and cytochalasin D (CCD) for periods of up to 3 h, most microvilli retracted to reveal a tight polar zone of CCD-resistant microvilli. This result suggests that a heterogeneity of cytocortical organization may still exist within the arrested mitotic cell. We propose a model to explain the origin of this heterogeneity of organization and its relationship to the generation of cell diversity.