Hansch analysis for the prediction of antimycobacterial activity of ofloxacin derivatives

The present study was attempted to predict the antimycobacterial activity of ofloxacin derivatives. The QSAR results indicated the importance of electronic properties of molecules viz. energy of the lowest unoccupied molecular orbital (LUMO), total energy (T _e), dipole moment (μ) and the topological parameter, third order shape index Kappa (κ₃) in describing the antimycobacterial activity of ofloxacin derivatives. The validity of developed models has been supported by significant statistical parameters.     

Local statistics in natural scenes predict the saliency of synthetic textures

The visual system is challenged with extracting and representing behaviorally relevant information contained in natural inputs of great complexity and detail. This task begins in the sensory periphery: retinal receptive fields and circuits are matched to the first and second-order statistical structure of natural inputs. This matching enables the retina to remove stimulus components that are predictable (and therefore uninformative), and primarily transmit what is unpredictable (and therefore informative). Here we show that this design principle applies to more complex aspects of natural scenes, and to central visual processing. We do this by classifying high-order statistics of natural scenes according to whether they are uninformative vs. informative. We find that the uninformative ones are perceptually nonsalient, while the informative ones are highly salient, and correspond to previously identified perceptual mechanisms whose neural basis is likely central. Our results suggest that the principle of efficient coding not only accounts for filtering operations in the sensory periphery, but also shapes subsequent stages of sensory processing that are sensitive to high-order image statistics.     

Synthesis, antimicrobial and antiviral evaluation of substituted imidazole derivatives

In the present study, we have synthesized 2-(substituted phenyl)-1H-imidazole (1-12) and (substituted phenyl)-[2-(substituted phenyl)-imidazol-1-yl]-methanone (13-26) analogues and screened them for their antimicrobial activity against gram positive, gram negative and fungal species. The results of antibacterial study indicated that compounds 15, 17 and 24 showed appreciable antibacterial activity and compound 26 emerged as the most potential antifungal agent. The results of SAR studies indicated that the presence of electron withdrawing groups is necessary for the antimicrobial activity of the synthesized compounds. The results of the present study indicated that compounds 15, 17 and 24 might be of interest for the identification of new antimicrobial molecules as their antibacterial activity is equivalent to the standard drug norfloxacin. Further, the antiviral screening of (substituted phenyl)-[2-(substituted phenyl)-imidazol-1-yl]-methanones (13-26) against a panel of viral strains indicated that compounds 16 and 19 can be selected as lead compounds for the development of novel antiviral agents.     

Effects of hydrogen sulfide on erectile function and its possible mechanism(s) of action

IntroductionThe current pharmacotherapy for erectile dysfunction (ED) relies significantly on the use of phosphodiesterase type 5 (PDE5) inhibitors, but quite a proportion of ED patients are resistant to this therapy, necessitating a search for an alternative treatment. We reviewed available published data to analyze current evidence of hydrogen sulfide (H₂S) as a novel pharmacotherapeutic agent with supportive role in sexual function.AimTo discuss the role of H₂S in erectile function, its possible mechanism of action, and how this knowledge may be exploited for therapeutic use.MethodsPubmed and Medline search was conducted to identify original articles and reviews.Main Outcome MeasuresData from peer‐reviewed publications.ResultsAnimal studies using different species, including in vitro study done in humans, show evidence of H₂S's pro‐erectile effects. The mechanism behind is still unclear, but evidence in literature points out the involvement of K⁺_ATP channel, modulation of protein with anti‐erectile effects, as well as involvement of the nitrergic pathway through a complex cross‐talk. A new drug called H₂S‐donating sildenafil (ACS6), which incorporated an H₂S‐donating moiety in sildenafil, has been developed. While more studies are still needed, this heralded a new pharmacotherapeutical approach, which is multipronged in nature.ConclusionsGiven the mounting evidence of H₂S's role in erectile function and how it appears to achieve its pro‐erectile effects through different mechanisms, H₂S represents a potentially important treatment alternative or adjunct to PDE5 inhibitors. Liaw RL, Srilatha B, and Adaikan PG. Effects of hydrogen sulfide on erectile function and its possible mechanism(s) of action. J Sex Med 2011;8:1853–1864.     

Blue lunula due to hydroxyurea

Alteration in the color of lunula can be an indication of either a cutaneous or systemic disorder or a systemic drug side effect. Hydroxyurea, an antitumor systemic agent (a ribonucleoside diphosphate reductase inhibitor) used in the treatment of refractory psoriasis as well as in the variety of neoplastic disorders is known to cause brownish pigmentation of the nails but hydroxyurea induced blue lunula is very rare. It is being reported in a 45-year-old man with chronic recalcitrant plaque psoriasis on oral hydroxyurea 500 mg twice daily. Lunular pigmentation in finger and toenails developed two weeks later. During follow up, pigmentation remained localized to the proximal portion of nails.     

Perforated sigmoid diverticulum mimicking acute appendicitis in a young patient: a case report

Acute colonic diverticula are uncommon in patients <40 years of age, with an incidence between 2% and 10%. In such patients, the condition may be misdiagnosed in the acute setting, because it is often not considered and may be mistaken for acute appendicitis, particularly if there are predominantly right-sided signs. As a result, it may result in diagnostic delay and complications. We report a case of a young patient who presented with a perforated sigmoid diverticulum mimicking acute appendicitis, which was not diagnosed initially, and the resulting course of events.     

Laparoscopic ureterocystoplasty before kidney transplantation

PURPOSE: To describe the technique of total laparoscopic ureterocystoplasty. MATERIALS AND METHODS: Laparoscopic ureterocystoplasty was performed to optimize the bladder function before kidney transplantation in a 23-year-old man. This patient had undergone bilateral cutaneous ureterostomy with fulguration of a posterior urethral valve at the age of 11 months. He underwent open surgical removal of multiple renal stones at age 10. He progressed to chronic renal failure at the age of 20, at which time hemodialysis was initiated. Because of grade IV vesicoureteral reflux and a poorly compliant bladder, the patient underwent laparoscopic ureterocystoplasty. RESULTS: The patient's lower urinary tract symptoms improved, and a urodynamic study performed after 6 months revealed a compliant bladder. Subsequently, a right nephrectomy and a live-donor renal transplantation from his mother were performed. At 1-year follow-up, his renal parameters were within normal range, he does not have any significant residual urine or urinary symptoms. CONCLUSION: Laparoscopic ureterocystoplasty is an excellent option for a poorly compliant bladder, especially when a patient has had multiple open surgeries and is awaiting renal transplantation.