Noninvasive monitoring of murine tumor blood flow during and after photodynamic therapy provides early assessment of therapeutic efficacy.

PURPOSE: To monitor tumor blood flow noninvasively during photodynamic therapy (PDT) and to correlate flow responses with therapeutic efficacy. EXPERIMENTAL DESIGN: Diffuse correlation spectroscopy (DCS) was used to measure blood flow continuously in radiation-induced fibrosarcoma murine tumors during Photofrin (5 mg/kg)/PDT (75 mW/cm2, 135 J/cm2). Relative blood flow (rBF; i.e., normalized to preillumination values) was compared with tumor perfusion as determined by power Doppler ultrasound and was correlated with treatment durability, defined as the time of tumor growth to a volume of 400 mm3. Broadband diffuse reflectance spectroscopy concurrently quantified tumor hemoglobin oxygen saturation (SO2). RESULTS: DCS and power Doppler ultrasound measured similar flow decreases in animals treated with identical protocols. DCS measurement of rBF during PDT revealed a series of PDT-induced peaks and declines dominated by an initial steep increase (average +/- SE: 168.1 +/- 39.5%) and subsequent decrease (59.2 +/- 29.1%). The duration (interval time; range, 2.2-15.6 minutes) and slope (flow reduction rate; range, 4.4 -45.8% minute(-1)) of the decrease correlated significantly (P = 0.0001 and 0.0002, r2= 0.79 and 0.67, respectively) with treatment durability. A positive, significant (P = 0.016, r2= 0.50) association between interval time and time-to-400 mm3 was also detected in animals with depressed pre-PDT blood flow due to hydralazine administration. At 3 hours after PDT, rBF and SO2 were predictive (P < or = 0.015) of treatment durability. CONCLUSION: These data suggest a role for DCS in real-time monitoring of PDT vascular response as an indicator of treatment efficacy.     

Candida biofilm resistance.

Device-related infections in most nosocomial diseases can be traced to the formation of biofilms (microbial communities encased within polysaccharide-rich extracellular matrix) by pathogens on surfaces of these devices. Candida species are the most common fungi isolated from these infections, and biofilms formed by these fungal organisms are associated with drastically enhanced resistance against most antimicrobial agents. This enhanced resistance contributes to the persistence of this fungus despite antifungal therapy. Candida biofilms exhibit enhanced resistance against most antifungal agents, except echinocandins and lipid formulations of AmB. The expression of drug efflux pumps during the early phase of biofilm formation and alterations in membrane sterol composition contribute to resistance of these biofilms against azoles. Metabolic dormancy and ECM do not appear to contribute to resistance, although in a mixed-species biofilm, ECM does retard the diffusion of drugs across biofilm. These multifactorial mechanisms of resistance in fungal biofilms constitute a broad-spectrum defense that is effective against many types of antifungal agents, and represent a common theme present across microbial biofilms.     

Identification and localisation of glycosyl moieties of surface glycoproteins of teliospore wall of Karnal bunt (Tilletia indica) of wheat

This article aims to characterise and localise the glycosyl moieties of teliospore wall of Tilletia indica a quarantined fungal pathogens by biochemical and immunological approaches. Chemical enzyme modifier studies, followed by determination of structural configuration using phase contrast and SEM after periodate treatment, showed antigenic entities are glycoprotein in nature. Further characterisation using sodium dodecyl sulphate-polyacrylamide gel electrophroesis (SDS-PAGE) glycoprotein staining and western blotting using anti-teliospore antibodies showed two common proteins of molecular weight 28 and 40 kDa, which is also suggestive of glycoprotein nature of antigenic entities of teliospore wall. To study the binding patterns and localisation of glycosyl moieties on the teliospore walls, fluorescein isothiocyanate (FITC) labelled lectins [Wheat Germ Agglutinin (WGA) and Concanavilin A (Con A)] and anti-teliospore antibodies were used. The patterns of WGA and anti-teliospore antibodies binding with teliospore wall are almost similar and hence it is quite reasonable to suggest that immunodominant glycosyl entities of teliospore wall are acetylglucosamine in nature.     

Isolated cardiac metastasis in a patient with neuroendocrine carcinoma of pancreas discovered on 68Ga-DOTANOC PET/CT

We present an interesting image that demonstrates utility of ⁶⁸Ga-DOTANOC PET/CT for demonstrating rare metastatic sites of neuroendocrime tumor.     

Melatonin inhibits matrix metalloproteinase‐9 activity by binding to its active site

The zinc‐dependent matrix metalloproteinases (MMPs) are key enzymes associated with extracellular matrix (ECM) remodeling; they play critical roles under both physiological and pathological conditions. MMP‐9 activity is linked to many pathological processes, including rheumatoid arthritis, atherosclerosis, gastric ulcer, tumor growth, and cancer metastasis. Specific inhibition of MMP‐9 activity may be a promising target for therapy for diseases characterized by dysregulated ECM turnover. Potent MMP‐9 inhibitors including an indole scaffold were recently reported in an X‐ray crystallographic study. Herein, we addressed whether melatonin, a secretory product of pineal gland, has an inhibitory effect on MMP‐9 function. Gelatin zymographic analysis showed a significant reduction in pro‐ and active MMP‐9 activity in vitro in a dose‐ and time‐dependent manner. In addition, a human gastric adenocarcinoma cell line (AGS) exhibited a reduced (~50%) MMP‐9 expression when incubated with melatonin, supporting an inhibitory effect of melatonin on MMP‐9. Atomic‐level interaction between melatonin and MMP‐9 was probed with computational chemistry tools. Melatonin docked into the active site cleft of MMP‐9 and interacted with key catalytic site residues including the three histidines that form the coordination complex with the catalytic zinc as well as proline 421 and alanine 191. We hypothesize that under physiological conditions, tight binding of melatonin in the active site might be involved in reducing the catalytic activity of MMP‐9. This finding could provide a novel approach to physical docking of biomolecules to the catalytic site of MMPs, which inhibits this protease, to arrest MMP‐9‐mediated inflammatory signals.     

Determinants of Postoperative Outcomes of Female Genital Fistula Repair Surgery

OBJECTIVE:: To determine predictors of fistula repair outcomes 3 months postsurgery. METHODS:: We conducted a multicountry prospective cohort study between 2007 and 2010. Outcomes, measured 3 months postsurgery, included fistula closure and residual incontinence in women with a closed fistula. Potential predictors included patient and fistula characteristics and context of repair. Multivariable generalized estimating equation models were used to generate adjusted risk ratios (RRs) and 95% confidence intervals (CIs). RESULTS:: Women who returned for follow-up 3-month postsurgery were included in predictors of closure analyses (n=1,274). Small bladder size (adjusted RR 1.57, 95% CI 1.39-1.79), prior repair (adjusted RR 1.40, 95% CI 1.11-1.76), severe vaginal scarring (adjusted RR 1.56, 95% CI 1.20-2.04), partial urethral involvement (adjusted RR 1.36, 95% CI 1.11-1.66), and complete urethral destruction or circumferential defect (adjusted RR 1.72, 95% CI 1.33-2.23) predicted failed fistula closure. Women with a closed fistula at 3-month follow-up were included in predictors of residual incontinence analyses (n=1,041). Prior repair (adjusted RR 1.37, 95% CI 1.13-1.65), severe vaginal scarring (adjusted RR 1.35, 95% CI 1.10-1.67), partial urethral involvement (adjusted RR 1.78, 95% CI 1.27-2.48), and complete urethral destruction or circumferential defect (adjusted RR 2.06, 95% CI 1.51-2.81) were significantly associated with residual incontinence. CONCLUSION:: The prognosis for genital fistula closure is related to preoperative bladder size, previous repair, vaginal scarring, and urethral involvement. LEVEL OF EVIDENCE:: II.