Cytodiagnosis of cutaneous histoplasmosis in HIV positive patient initially presenting with multiple umbilicated disseminated skin nodules

Histoplasmosis is usually an opportunistic fungal infection in patients with defective cell mediated immunity, and has been considered as one of the acquired immunodeficiency syndrome (AIDS) defining illness. However, cutaneous involvement in human immunodeficiency virus (HIV) positive patients is less common, and very rarely can be the initial presenting symptom for the diagnosis of AIDS. We present here an unusual case of multiple diffuse cutaneous nodular lesions predominantly in face, trunk, and upper extremities diagnosed initially on aspiration cytology as histoplasmosis. Subsequent serological test revealed positivity for HIV 1 and 2, along with a low CD4 count and low CD4:CD3 ratio. The cytomorphological features were further corroborated by histology and histochemical stains. Hence, cutaneous histoplasmosis can cause multiple wide spread nodular or umbilicated lesions in AIDS patients as the initial presentation. Fine needle aspiration cytology (FNAC) is a rapid, cost effective tool for diagnosis of the fungi from such lesions and initiating work up for immunocompromised states including AIDS. Diagn. Cytopathol. 2013. © 2011 Wiley Periodicals, Inc.     

4-Methyl-2,6-diformylphenol based biocompatible chemosensors for pH: discrimination between normal cells and cancer cells

Two compounds, namely, 2-hydroxy-5-methyl-3-((pyridin-2-ylimino)methyl)benzaldehyde (HM-2py-B) and 2-hydroxy-5-methyl-3-((pyridin-3-ylimino)methyl)benzaldehyde (HM-3py-B), have been explored as fluorescent chemosensors for pH. HM-2py-B and HM-3py-B were synthesized by single step condensation reaction between 4-methyl-2,6-diformylphenol and the appropriate aminopyridine. These compounds have been characterized by elemental analysis, FT-IR, ¹H NMR, ¹³C NMR, ESI mass spectrometry, and absorption and fluorescence spectroscopy. Their structures have been confirmed by single crystal X-ray diffraction analysis. Both of the compounds show low emission at 530 nm at low pH. Fluorescence intensity increases with the increase in pH. With the alteration in pH of the medium from 4.0 to 10.0, the fluorescence intensity at 530 nm enhances by 66 and 195 fold for HM-2py-B and HM-3py-B, respectively. pK_a values of HM-2py-B and HM-3py-B have been determined to be 7.15 and 6.57, respectively. Fluorescence increase occurs mainly due to deprotonation of the phenolic OH group. Several cations and anions could not induce significant change in fluorescence behavior for both of the probes. The quantum yield and life-time enhance significantly when the pH of the medium is changed from 5.0 to 9.0. Naked eye identification of different pH environments is possible by using these compounds. Some theoretical calculations have been carried out to support experimentally obtained spectral transitions. As cancer cell has a pH in the range of 5.5–7.0 in comparison to normal cell pH of 7.4, these probes have been used effectively to discriminate between normal cells and cancer cells.

Two 4-methyl-2,6-diformylphenol based compounds with pyridylamine have been established as chemosensors for pH. The probes are able to differentiate between normal cells and cancer cells.     

Isolated vertebral artery injury secondary to suicidal neck stab

Traumatic vertebral artery injuries may be due to blunt or penetrating forces, the presentation of which can vary from being asymptomatic to a life threatening torrential bleed. The following case report describes an isolated vertebral artery injury with a rare mode of injury and presentation along with its management.     

Histone deacetylase inhibitors as potential therapeutic approaches for chordoma: An immunohistochemical and functional analysis

Chordomas are rare malignancies of the axial skeleton. Therapy is mainly restricted to surgery. This study investigates histone deacetylase (HDAC) inhibitors as potential therapeutics for chordomas. Immunohistochemistry (IHC) was performed using the HDAC 1–6 antibodies on 50 chordoma samples (34 primary tumors, 16 recurrences) from 44 patients (27 male, 17 female). Pan‐HDAC‐inhibitors Vorinostat (SAHA), Panobinostat (LBH‐589), and Belinostat (PXD101) were tested for their efficacy in the chordoma cell line MUG‐Chor1 via Western blot, cell cycle analysis, caspase 3/7 activity (MUG‐Chor1, UCh‐1), cleaved caspase‐3, and PARP cleavage. p‐Values below 0.05 were considered significant. IHC was negative for HDAC1, positive for HDAC2 in most (n = 36; 72%), and for HDACs 3–6 in all specimens available (n = 43; 86%). HDAC6 expression was strongest. SAHA and LBH‐589, but not PXD101 caused a significant increase of G2/M phase cells and of cleaved caspase‐3 (p = 0.0003, and p = 0.0014 after 72 h, respectively), and a peak of caspase 3/7 activity. PARP cleavage confirmed apoptosis. The presented chordoma series expressed HDACs 2–6 with strongest expression of HDAC6. SAHA and LBH‐589 significantly increased apoptosis and changed cell cycle distribution in vitro. HDAC‐inhibitors should be further evaluated as therapeutic options for chordoma. © 2013 Orthopaedic Research Society Published by Wiley Periodicals, Inc. J Orthop Res 31:1999–2005, 2013     

(ii) Biomechanics of implant fixation

In joint replacement, stability of the implant is provided by a combination of the techniques adopted to fix the implant to the surrounding bone and the geometric features of the implant. Fixation techniques can either use cement or be cementless. Cemented fixation uses PMMA bone cement to grout the implant and bone together, while cementless fixation involves either a press-fit between the implant and bone, or specific design features that encourage bone growth into or onto the implant. Although both of these fixation techniques perform well in terms of longevity, each method functions better than the other in certain patient groups, and each has some positives and negatives. This article reports an overview of the fundamental aspects of the fixation techniques, their clinical advantages and disadvantages, associated clinical concerns and recent trends of fixation in clinical practice. This will be coupled with specific examples on how certain geometric features of an implant help in achieving initial and long-term stability and fixation.