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Herein, we describe a rapid and facile fabrication of electrochemical sensors utilizing two different toll-like receptor (TLR) proteins as biorecognition elements to detect bacterial pathogen associated molecular patterns (PAMPs). Using potential-assisted self-assembly, binary mixtures of 11-mercaptoundecanoic acid (MUA) and 6-mercapto-1-hexanol (MCH), or MUA and an in-house synthesized zwitterionic sulfobetaine thiol (DPS) were assembled on a gold working electrode within 5 minutes, which is >200 times shorter than other TLR sensors' preparation time. Electrochemical methods and X-ray photoelectron microscopy were used to characterize the SAM layers. SAMs composed of the betaine terminated thiol exhibited superior resistance to nonspecific interactions, and were used to develop the TLR sensors. Biosensors containing two individually immobilized TLRs (TLR4 and TLR9) were fabricated on separate MUA-DPS SAM modified Au electrodes (MUA-DPS/Au) and tested for their response towards their respective PAMPs. The changes to electron transfer resistance in EIS of the TLR4/MUA-DPS/Au sensor showed a detection limit of 4 ng mL -1 for E. coli 0157:H7 endotoxin (lipopolysaccharide, LPS) and a dynamic range of up to 1000 ng mL -1 . The TLR4-based sensor showed negligible response when tested with LPS spiked human plasma samples, showing no interference from the plasma matrix. The TLR9/MUA-DPS/Au sensor responded linearly up to 350 μg mL -1 bacterial DNA, with a detection limit of 7 μg mL -1 . The rapid assembly of the TLR sensors, excellent antifouling properties of the mixed SAM assembly, small size and ease of operation of EIS hold great promise for the development of a portable and automated broad-spectrum pathogen detection and classification tool.

The adoption of supplementary cementitious materials (SCMs) as a partial replacement of Ordinary Portland Cement (OPC) is increasing in anticipation of reducing the carbon footprint of cement and concrete industry. The resistance of concretes with SCMs against natural carbonation (a reactive-diffusion mechanism) is still a topic of research. Most literature adopt accelerated carbonation tests (under constant humidity and temperature conditions) to estimate the natural carbonation depth (d CO2 ) in concrete. This does not always represent the actual scenario in the field structures. Moreover, accelerated carbonation conditions could result in significantly different pore structure than that are formed in the case of natural carbonation; hence, not always reliable to model the service life. Hence, there is a need for data on long-term natural d CO2 to help design reinforced concrete for a target service life. The data presented in this paper contains long-term natural d CO2 data of 45 different concretes prepared using various SCMs like volcanic ash (from Greece), fly ash, slag, and limestone (from France). The concrete specimens were prepared in France, shipped to India by air (in moist burlap and plastic cover), and then kept in sheltered and unsheltered exposure conditions on the terrace of a building in Chennai, India, experiencing tropical climate (warm and humid conditions). The data includes mixture proportions (type of binder, water-to-binder ratio, binder content, % SCMs, fine and coarse aggregate (river sand and gravel) content, and air content). In addition, curing time and compressive strength of concrete mixes are provided in Set A. Sets B and C consist of the natural d CO2 of concrete measured at various time instances between 1 and 11 years of natural exposure. Arguably, this is the first of its kind natural d CO2 database from a tropical climate zone. The natural d CO2 values were measured using a phenolphthalein indicator prepared according to RILEM CPC 18. This data can be used by researchers and practitioners to calibrate the existing carbonation models or to develop new models to estimate natural d CO2 for concretes exposed to tropical climates. Such models can help design concretes to achieve the target corrosion-free service life for reinforced concrete systems., (© 2024 The Authors.)

In this work, we report the direct electrochemical oxidation of fentanyl using commercial screen-printed carbon electrodes (SPCEs) modified with carboxyl-functionalized carbon nanofibers (fCNFs). CNFs have surface chemistry and reactivity similar to carbon nanotubes (CNTs), yet they are easier to produce and are of a lower cost than CNTs. By monitoring the current produced during the electrochemical oxidation of fentanyl, variables such as fCNF loading, fentanyl accumulation time, electrolyte pH, and differential pulse voltammetry parameters were optimized. Under an optimized set of conditions, the fCNF/SPCEs responded linearly to fentanyl in the concentration range of 0.125-10 μM, with a limit of detection of 75 nM. The fCNF/SPCEs also demonstrated excellent selectivity against common cutting agents found in illicit drugs (e.g., glucose, sucrose, caffeine, acetaminophen, and theophylline) and interferents found in biological samples (e.g., ascorbic acid, NaCl, urea, creatinine, and uric acid). The performance of the sensor was also successfully tested using fentanyl spiked into an artificial urine sample. The straightforward electrode assembly process, low cost, ease of use, and rapid response make the fCNF/SPCEs prime candidates for the detection of fentanyl in both physiological samples and street drugs., Competing Interests: The authors declare no competing financial interest., (Crown © 2024. Published by American Chemical Society.)

The KEAP1/NRF2 pathway promotes metabolic rewiring to support redox homeostasis. Activation of NRF2 occurs in many cancers, often due to KEAP1 mutations, and is associated with more aggressive disease and treatment resistance. To identify metabolic dependencies in cancers with NRF2 activation, we performed a metabolism-focused CRISPR screen. Glucose-6-phosphate dehydrogenase (G6PD), which was recently shown to be dispensable in Ras-driven tumors, was a top dependency. G6PD catalyzes the committed step of the oxidative pentose phosphate pathway that produces NADPH and nucleotide precursors, but neither antioxidants nor nucleosides rescued. Instead, G6PD loss triggered tricarboxylic acid (TCA) intermediate depletion because of up-regulation of the alternative NADPH-producing enzymes malic enzyme and isocitrate dehydrogenase. In vivo, G6PD impairment markedly suppressed KEAP1 mutant tumor growth, and this suppression was further augmented by TCA depletion by glutaminase inhibition. Thus, G6PD inhibition–induced TCA depletion is a therapeutic vulnerability of NRF2-activated cancer.

Purpose: Phytochemicals of ethno medicines are being developed as effective drugs with minimum or no toxic side effects. Dhanwantaram Kashayam (DK) is a polyherbal formulation used as a potent general health tonic and is found to have antioxidant activities, but there are no proper scientific studies on its possible benefits. In this study we investigated the antioxidant and antidiabetic properties of DK and trying to explore the possibility of employing DK for the treatment of diseases like diabetes mellitus caused by the imbalance in Reactive Oxygen Species (ROS)., Methods: We investigated the effect of DK on normal and rat model of diabetes. Rats were fed with DK for 21 days. Fasting blood glucose level, haemoglobin, glycosylated hemoglobin, non enzymatic antioxidants like vitamin C, vitamin E, reduced glutathione, and MDA were evaluated., Results: DK was found to ameliorate the disease symptoms of diabetes. A significant decrease in non enzymatic antioxidants - vitamin C, vitamin E, reduced glutathione and an increase in MDA and fasting blood glucose level was observed in diabetic rats. Administration of DK resulted significant increase in non enzymatic antioxidant levels both in diabetic and normal rats and a decrease in MDA, fasting blood glucose, glycosylated hemoglobin and HOMA-IR index was observed., Conclusion: This study reveals the protective role of DK in diabetic condition through its antioxidant and antihyperglycemic activity. Our results strongly indicate the possibility of DK being developed as a potent antidiabetic drug. DK could be an alternative in the treatment of diseases with ROS imbalance to expensive and toxic synthetic 'medicines'., Competing Interests: Conflict of interestAuthors report no conflict of interest., (© Springer Nature Switzerland AG 2020.)

Background: Hyperglycemia and hyper oxidative stress are indicators of diabetes mellitus which is also accompanied with decreased levels of antioxidant enzymes. While oxidative stress is important in increasing insulin secretion and controlling blood sugar level at the same time excess oxidative stress leads to the destruction of beta cells of pancreas resulting in to low insulin production and hyperglycemia. A balance between the levels of oxidative radicals and insulin production is needed, but is not defined yet. Hyperglycemia also leads to hyperlipidemia which can contribute to various health conditions like cardiovascular diseases., Objectives: This study was designed to study the oxidative stress and lipid levels in diabetic rats. This also was designed to elucidate the effect of Dhanwantaram Kashayam, an Ayurvedic polyphenolic derived from plants on lipid metabolism and oxidative radical scavenging in diabetic rats., Methods: Rats were made diabetic by injecting streptozotocin. Different enzymes involved in oxidative radical scavenging and lipid profiles including triglycerides, total cholesterol, free fatty acids and phospholipids were estimated using standard methods reported elsewhere., Results: Level of antioxidant enzymes were lower in diabetic rats compared to normal controls. Administration of Dhanwantaram Kashayam restored the enzyme activity as well as reduced levels of different lipids in diabetic rats., Conclusions: Administration of Dhanwantaram Kashayam increased the activity levels of antioxidant enzymes and reduced the levels of total cholesterol, phospholipids and triglycerides. The results of this study point to the possibility of developing Dhanwantaram Kashayam as a dietary supplement which can alleviate the complications associated with diabetes or prevent them altogether., Competing Interests: The authors declare no conflict of interest, financial or otherwise., (© 2020 The Authors.)

Nanostructured nickel (Ni) and nickel oxide (NiO) electrodes were fabricated on Ni foils using the glancing angle deposition (GLAD) technique. Cyclic voltammetry and amperometry showed the electrodes enable non-enzymatic electrochemical determination of glucose in strongly alkaline media. Under optimized conditions of NaOH concentration and working potential (~ 0.50 V vs. Ag/AgCl), the GLAD electrodes performed far better than bare Ni foil electrodes, with the GLAD NiO electrode showing an outstanding sensitivity (4400 μA mM -1  cm -2 ), superior detection limit (7 nM), and wide dynamic range (0.5 μM-9 mM), with desirable selectivity and reproducibility. Based on their performance at a low concentration, the GLAD NiO electrodes were also used to quantify glucose in artificial urine and sweat samples which have significantly lower glucose levels than blood. The GLAD NiO electrodes showed negligible response to the common interferents in glucose measurement (uric acid, dopamine, serotonin, and ascorbic acid), and they were not poisoned by high amounts of sodium chloride. Graphical abstract The figures depict (A) SEM image of vertical post-GLAD NiO electrodes used for non-enzymatic electrochemical glucose monitoring, and (B) calibration plots of the three different electrodes.

Two kinds of electrochemical impedimetric biosensors for the detection of E. coli O157:H7 are described and compared. They were fabricated using self-assembled layers of thiolated protein G (PrG-thiol) on (i) planar gold electrodes and (ii) gold nanoparticles (Au NPs) modified gold electrodes. The fabrications of the biosensors were characterized using cyclic voltammetry, electrochemical impedance spectroscopy, scanning electron microscopy and atomic force microscopy techniques. The modification of the planar gold electrode by Au NPs via self-assembled monolayer of 1,6-hexadithiol as a linker molecule increased the electrochemically active surface area by about 2.2 times. The concentration of PrG-thiol and its incubation time, as well as the concentration of IgG were optimized. The Au NP-based biosensor exhibited a limit of detection of 48 colony forming unit (cfu mL -1 ) which is 3 times lower than that of the planar gold electrode biosensor (140 cfu mL -1 ). It also showed a wider dynamic range (up to 10 7  cfu mL -1 ) and sensitivity. The improved analytical performance of the Au NP-modified biosensor is ascribed to the synergistic effect between the Au NPs and the PrG-thiol scaffold. The biosensor exhibited high selectivity for E. coli O157:H7 over other bacteria such as Staphylococcus aureus and Salmonella typhimurium. Graphical abstract Schematic representations of sensor fabrication using Au NP-modified electrode (HKEC = heat- killed E. coli O157:H7).

Objective: To assess the benefit of a new technique of a Plastibell circumcision supported by a ventral calcium-alginate fibre dressing, to reduce bleeding from the frenular vessels, the commonest complication of Plastibell circumcision., Patients and Methods: This was a retrospective study of 200 neonates circumcised in the Royal Bahrain Hospital over a 2-year period from 2012 to 2014. They had a standard Plastibell circumcision, but a calcium-alginate fibre dressing (Hypo-sorb, Plastod, Italy) was placed over the glans and under the foreskin, to help control bleeding from the frenular vessels., Results: Circumcision using the calcium-alginate fibre dressing reduced the bleeding complication rate to zero. The delayed separation of the bell was 2.9% when using the new technique and 2.5% from our previous data. There were no cases of urinary retention reported, compared to two in the previous results., Conclusion: A Plastibell circumcision supported by the calcium-alginate fibre dressing was a safe technique to reduce bleeding.

Objective: To compare the perioperative morbidity and early follow-up after diode laser vaporisation of the prostate (LVP) and its modification, diode laser under cold irrigation (LUCI) in patients with symptomatic benign prostatic hyperplasia, as the main disadvantages of LVP are the postoperative pain, dysuria and storage urinary symptoms., Patients and Methods: This was a single-centre prospective randomised control trial in which 100 patients were randomised to receive LVP (50) or LUCI (50) from June 2011 until July 2012. LUCI is similar to LVP except that it is done under normal irrigation with saline at 4 °C instead of saline at room temperature. The primary outcome measures were the International Prostate Symptom Score (IPSS), IPSS-Dysuria, a pain scale (PS), maximum flow rate (Q max), a quality-of-life (QoL) score and the postvoid residual urine volume (PVR) after 1 month, then the IPSS, Q max, QoL, and PVR at 3 and 12 months. Secondary outcomes included intraoperative surgical variables, e.g., the decline in core temperature, bleeding, peri- and postoperative morbidity., Results: The baseline characteristics of both groups were similar. For the primary outcome measures, there was a statistically significant difference between the groups in all variables except Q max after 1 month, in favour of LUCI. The mean (SD) IPSS at 1 month in the LVP group was 8.97 (1.68), statistically significantly different from that after LUCI, of 6.89 (1.5) (P < 0.05). The mean IPSS-Dysuria at 1 month was also significantly, at -2.32 (0.91) for LVP and 3.54 (1.07) for LUCI (P < 0.05). The respective mean PS at 1 month was 7.84 (2.92) and 5.7 (2.1) (P < 0.05). The QoL and PVR at 1 month were also significantly different. Within the first month 17% of patients in the LVP group and 4% in the LUCI group complained of transient urgency or stress incontinence, and this difference was statistically significant (P < 0.05). There was no significant bleeding in either group. The mean operative time or applied energy of LVP was not statistically significant from that of LUCI, and there was no significant difference in the decline in core temperature between the groups (P > 0.05)., Conclusion: LUCI is a good modification for reducing the pain, dysuria and storage symptoms associated with LVP. The procedure appears to be safe, with no significant decrease in core temperature in either group.

The performance of redox-gated organic nonvolatile memory (NVM) based on conducting polymers was investigated by altering the polymer structure, composition, and local environment of three-terminal devices with a field-effect transistor (FET) geometry. The memory function was dependent on the presence of a redox active polymer with high conducting and low conducting states, the presence of a redox counter-reaction, and the ability to transport ions between the polymer and electrolyte phases. Simultaneous monitoring of both the "write" current and "readout" current revealed the switching dynamics of the devices and their dependence on the local atmosphere. Much faster and more durable response was observed in acetonitrile vapor than in a vacuum, indicating the importance of polar molecules for both ion motion and promotion of electrochemical reactions. The major factor determining "write" and "erase" speeds of redox-gated polymer memory devices was determined to be the rate of ion transport through the electrolyte layer to provide charge compensation for the conducting polarons in the active polymer layer. The results both confirm the mechanism of redox-gated memory action and identify the requirements of the conducting polymer, redox counter reaction, and electrolyte for practical applications as alternative solid-state nonvolatile memory devices.

A three terminal molecular memory device was monitored with in situ Raman spectroscopy during bias-induced switching between two metastable states having different conductivity. The device structure is similar to that of a polythiophene field effect transistor, but ethylviologen perchlorate was added to provide a redox counter-reaction to accompany polythiophene redox reactions. The conductivity of the polythiophene layer was reversibly switched between high and low conductance states with a "write/erase" (W/E) bias, while a separate readout circuit monitored the polymer conductance. Raman spectroscopy revealed reversible polythiophene oxidation to its polaron form accompanied by a one-electron viologen reduction. "Write", "read", and "erase" operations were repeatable, with only minor degradation of response after 200 W/E cycles. The devices exhibited switching immediately after fabrication and did not require an "electroforming" step required in many types of memory devices. Spatially resolved Raman spectroscopy revealed polaron formation throughout the polymer layer, even away from the electrodes in the channel and drain regions, indicating that thiophene oxidation "propagates" by growth of the conducting polaron form away from the source electrode. The results definitively demonstrate concurrent redox reactions of both polythiophene and viologen in solid-state devices and correlate such reactions with device conductivity. The mechanism deduced from spectroscopic and electronic monitoring should guide significant improvements in memory performance.

Spontaneous self-assembly of alkylthiosulfates on gold produce monolayers similar to the corresponding alkanethiols. Alkylthiosulfate self-assembly from THF solutions is inhibited in the presence of tetrabutylammonium tetrafluoroborate electrolyte. The mechanism of alkylthiosulfate self-assembly and the role of electrolyte and trace water in the solvent are investigated using open-circuit potential measurements, contact angle goniometry and redox electron transfer blocking experiments to explore the hypothesis that trace water present in the solvent facilitates monolayer formation on gold. Furthermore, the unique behavior of tetrabutylammonium tetrafluoroborate, compared to other tetrabutylammonium electrolytes, on the inhibition of alkylthiosulfate self-assembly has been explained.

With advances in stem cell biology, tissue engineering is becoming increasingly powerful for tissue regeneration. Stem cells with capacity of multilineage and self-renewal are an ideal cell source for tissue engineering. This review focus on discussing the potential strategies including stem cell sources, bio-scaffolds, mechanical stimulation, genetic modification and co-culture techniques to direct ocular-lineage differentiation of stem cells for complete or partial eye regeneration and research. Attempts to use embryonic and somatic stem cells as seed cells for ocular tissue engineering have achieved encouraging results. The combination of chemical and physical signals in stem cell microenvironment could be regulated to induce differentiation of the embryonic stem cells into ocular tissue. This paper present here a broad introduction to the stem cell mediated correction of eye ailments and provide extensive references for the interested reader. This paper also looks into the different aspects of using stem cells for drug development for treating eye ailments.

Dynamic resistive memory devices based on a conjugated polymer composite (PPy(0)DBS(-)Li(+) (PPy: polypyrrole; DBS(-): dodecylbenzenesulfonate)), with field-driven ion migration, have been demonstrated. In this work the dynamics of these systems has been investigated and it has been concluded that increasing the applied field can dramatically increase the rate at which information can be 'written' into these devices. A conductance model using space charge limited current coupled with an electric field induced ion reconfiguration has been successfully utilized to interpret the experimentally observed transient conducting behaviors. The memory devices use the rising and falling transient current states for the storage of digital states. The magnitude of these transient currents is controlled by the magnitude and width of the write/read pulse. For the 500 nm length devices used in this work an increase in 'write' potential from 2.5 to 5.5 V decreased the time required to create a transient conductance state that can be converted into the digital signal by 50 times. This work suggests that the scaling of these devices will be favorable and that 'write' times for the conjugated polymer composite memory devices will decrease rapidly as ion driving fields increase with decreasing device size.

Electrochemically directed self-assembly of alkylthiosulfates enables the selective formation of monolayers on gold surfaces. These monolayers are identical to those formed from the corresponding alkanethiols. However, the mechanistic details of monolayer formation under electrochemical conditions as well as the role of other variables and residual water in the solvent have not been extensively studied. A systematic investigation shows that self-assembly is not a result of an outer-sphere one-electron oxidation of alkylthiosulfate. Voltammetry and electrochemical quartz crystal microbalance techniques reveal that self-assembly involving alkylthiosulfates as well as alkanethiols under oxidative conditions proceed through direct reaction with gold oxide and in some cases is accompanied by corrosion. X-ray photoelectron spectroscopy indicates that monolayers can undergo rapid exchange with molecules in solution under electrochemically directed self-assembly conditions.

Background: The expression of chemokines is central to the recruitment of inflammatory cells for graft rejection, and modulation of chemokine action is of potential in preventing graft rejection. We have examined chemokine expression in a murine model of corneal allograft rejection, and also determined the effect of expressing a broad acting chemokine antagonist, viral macrophage inflammatory protein II (vMIP II), on graft survival., Method: The expression of chemokines in a murine model of corneal transplantation was determined by real time RT-PCR and, in the case of regulated on activation normal T-cell expressed and secreted, by ELISA. The plasmid encoding the virally derived chemokine antagonist, vMIP II, was introduced into the corneal endothelial cells using a non-viral vector consisting of liposomes and transferrin. The expression and activity of vMIP II was determined by ELISA and functional assays, and the effect on graft survival noted., Results: After allotransplantation, there was up-regulation of all 11 chemokines examined. After gene delivery, there was expression of active vMIP II for more than 14 days and considerable prolongation of graft survival. This was associated with a decrease in leukocyte infiltration of the stroma of the cells., Conclusion: As expected there was considerable up-regulation of chemokines during allograft rejection. The expression of vMIP II showed considerable prolongation of graft survival. This is the first time we have observed prolongation of graft survival after a non-viral (as opposed to viral) means of gene delivery and indicates the potential of interfering with chemokine action to prevent corneal graft failure.

The assessment of tissue-specific pharmacodynamics is desirable in the development of tumor-targeted therapies. Plasma deoxyuridine (dUrd) levels, a measure of systemic thymidylate synthase (TS) inhibition, has limited application for studying the pharmacodynamics of novel TS inhibitors targeted to the high affinity alpha-folate receptor (FR). Here, we have evaluated the utility of [(18)F]fluorothymidine positron emission tomography ([(18)F]FLT-PET) for imaging the tissue pharmacodynamics of BGC 945, an FR-targeted antifolate TS inhibitor; the nontargeted antifolate BGC 9331 was used for comparison. TS inhibition by both drugs induced a concentration-dependent increase in [(3)H]thymidine uptake in FR-positive human epidermoid KB cells. Membrane-associated equilibrative nucleoside transporter type 1 levels increased from 55,720 +/- 6,101 to 118,700 +/- 5,193 and 130,800 +/- 10,800 per cell at 100 mug/mL of BGC 9331 and BGC 945, respectively, suggesting this as a potential mechanism of increased nucleoside uptake. In keeping with these in vitro findings, tumor [(18)F]FLT accumulation in KB xenografts increased by >/=2-fold after drug treatment with maximal levels at 1 to 4 hours and 4 to 24 hours after BGC 9331 and BGC 945 treatment, respectively. Of interest to FR targeting, BGC 9331, but not BGC 945, induced accumulation of [(18)F]FLT uptake in intestine, a proliferative and TS-responsive tissue. For both drugs, quantitative changes in tumor [(18)F]FLT uptake were associated with increased tumor dUrd levels. In conclusion, we have validated the utility of [(18)F]FLT-PET to image TS inhibition induced by antifolates and shown the tumor-specific activity of BGC 945. This imaging biomarker readout will be useful in the early clinical development of BGC 945.

Background and Aims: Allograft rejection is the commonest cause of corneal transplant failure and is significantly higher in high-risk patients. Corneal tissue is reported to produce chemokines in response to stress/inflammation. Expression of chemokines is central to the recruitment of leucocytes during inflammatory events. This study was designed to evaluate the effects of surgical trauma or storage conditions on chemokine expression., Methods: Murine corneas were manipulated by incubation in different conditions for up to 24 h, by the addition of endotoxin or by surgical trauma. The ex vivo production of chemokines was assessed using a real-time reverse-transcriptase PCR (RT-PCR) assay to measure mRNA encoding MIP-1alpha, MIP-1beta and MIP-1gamma, MCP1, IP-10, lymphotactin, fractalkine, RANTES, eotaxin, MIG, MIP2 and the cytokine MIF. The expression of RANTES was also determined by ELISA, and the ability of supernatant from corneas on chemotaxis of cells was also determined. Finally, we compared the survival of corneal grafts that had (or had not) been treated with endotoxin., Results: We found that on incubation in corneal storage medium, expression of mRNA for the majority of these chemokines greatly increased. Upregulation of chemokine mRNA expression was also seen following the mechanical trauma of suture insertion and exposure of the cornea to endotoxin. In the case of mechanical trauma, functional activity of the chemokines was demonstrated using a chemotaxis assay. Orthotopic transplantation of LPS-treated corneas, in which chemokine expression was elevated, resulted in increased infiltration by leucocytes and more rapid rejection of allogeneic grafts., Conclusion: Our results indicate that ex vivo storage and manipulation of murine corneas can influence the expression of chemokines in corneas, and can result in earlier graft rejection. This may be of importance when considering procedures for manipulation and ex vivo storage of donor corneas prior to transplantation, as well as the surgical procedure itself.

Graft rejection is critically dependent on the recruitment of leukocytes via adhesion molecules on the endothelium, and inhibition of these interactions can prolong graft survival. We have therefore developed an approach using siRNA to inhibit the expression of VCAM-1 in endothelial cells. We transfected siRNA constructs into murine corneal and vascular endothelium and looked at expression of VCAM-1 and other surface molecules by flow cytometry. Adhesion assays (both static and under flow) were used to determine the effect of VCAM-1 inhibition. The activation of cellular stress responses was assessed by RT-PCR. Constructs encoding siRNA can block expression of VCAM-1 in both corneal and vascular endothelial cells (in the latter case after cytokine stimulation). Inhibition of VCAM-1 expression reduced the ability of T cells to adhere to endothelium. However, there were non-specific effects of siRNA expression, including upregulation of (Programmed Death Ligand 1) PDL1 and decreased cell growth. Analysis of stress pathways showed that the endothelial cells transfected with siRNA had upregulated molecules associated with cell stress. While these data are supportive of a potential therapeutic role for siRNA constructs in blocking the expression of adhesion molecules, they also highlight potential non-specific effects of siRNA that must be carefully considered in any application of this technology.

Thymidylate synthase (EC 2.1.1.45) is a key enzyme for the de novo synthesis of DNA and as such a target for anticancer drug development. There is a need to develop noninvasive methods for assessing thymidylate synthase inhibition in tumors. The aim of this study was to assess the potential of 3'-deoxy-3'-[(18)F]fluorothymidine ([(18)F]FLT) positron emission tomography (PET) for early measurement of thymidylate synthase inhibition and to elucidate the cellular mechanisms involved. Radiation-induced fibrosarcoma-1 tumor-bearing mice were injected with a single i.p. dose of the thymidylate synthase inhibitor 5-fluorouracil (5-FU; 165 mg/kg) and imaged by [(18)F]FLT-PET at 1 to 2 hours after treatment. Deoxyuridine, thymidine kinase 1 (cytoplasmic thymidine kinase; EC2.7.1.21), and ATP levels in excised tumors were measured. Cellular assays for membrane transport were also done. There was a 1.8-fold increase in the 60-minute [(18)F]FLT tumor/heart radioactivity ratio in drug-treated mice compared with vehicle controls (P = 0.0016). Plasma and tumor deoxyuridine levels increased significantly but thymidine kinase and ATP levels were unchanged. Whole-cell assays implicated a (low level) functional role for the type-1 equilibrative nucleoside transporter (ENT). There was an increase in type-1 ENT-binding sites per cell from 49,110 in untreated cells to 73,142 (P = 0.03) in cells treated with 10 microg/mL 5-FU for 2 hours, without a change in transporter affinity (P = 0.41). We conclude that [(18)F]FLT-PET can be used to measure thymidylate synthase inhibition as early as 1 to 2 hours after treatment with 5-FU by a mechanism involving redistribution of nucleoside transporters to the plasma membrane.

Purpose: We recently showed an increase in tumour uptake of 2-[(11)C]thymidine in patients with gastrointestinal malignancies after thymidylate synthase (TS) inhibition. To understand the phenomenon in more detail, we investigated whether TS inhibition by different TS inhibitors leads to a dose- and time-dependent change in the uptake of radiolabelled thymidine, and whether radiotracer uptake is related to changes in cell viability resulting from treatment., Methods: RIF-1 and HT29 cells were treated with the TS inhibitors 5-fluorouracil (5-FU) and AG337 (nolatrexed dihydrochloride), as well as cisplatin as control. The cell viability and net accumulation of [(3)H]thymidine after a 1-h pulse was determined at different times after drug treatment., Results: In both cell lines, [(3)H]thymidine uptake increased after a 2-h treatment with 5-FU, in a dose- and time-dependent manner. [(3)H]thymidine uptake decreased at 24 and 48 h post treatment. AG337 also produced a similar effect. In contrast to the TS inhibitors, cisplatin decreased [(3)H]thymidine uptake in RIF-1 and HT29 cells at all time points. Cell viability was compromised only after 24 h., Conclusion: Using two types of TS inhibitor, we have shown an increase in [(3)H]thymidine uptake, in a dose-dependent manner, a few hours after TS inhibition when the cell viability was not compromised. This effect was not seen with a non-TS inhibitor. These findings suggest that 2-[(11)C]thymidine positron emission tomography can be used to study TS inhibition in vivo at early time points when cell viability is not compromised and may therefore be helpful in the development of new TS inhibitors and in differentiating between patients with tumours sensitive to TS inhibitors and those unlikely to respond.

A case of myofibroblastoma of the breast was recently diagnosed in an adolescent Omani boy. In this report, the clinical, histopathological and the radiological features of this rare disease are being discussed. We conclude that, myofibroblastoma of the breast, which was earlier described, predominantly, in elderlies, can occur in people from any age group.

Background: This study was performed to evaluate the effectiveness of suction drainage in the management of early poststernotomy mediastinitis., Methods: From September 1998 to August 1999, we encountered nine cases of poststernotomy mediastinitis out of 1,209 adult median sternotomies performed in this time period. All these cases were treated with suction drainage, which was recently introduced to our management protocol. From September 1997 to August 1998, we encountered 11 cases of poststernotomy mediastinitis of 1,343 adult median sternotomies. All these cases were initially treated by closed drainage and irrigation, which was our previous first-line management. We used the latter group as historical controls for the evaluation of suction drainage. Lengths of hospitalization were compared using the Mann-Whitney U test, and success versus failure of the primary treatment was compared using the chi2 test., Results: Treatment with the suction dressing resulted in a decreased length of hospitalization after treatment starts (p = 0.02) and a lower rate of treatment failure (p = 0.03)., Conclusions: The use of high-pressure suction drainage is a valuable adjunct in the early management of poststernotomy mediastinitis.

Aortic root replacement with sparing of the aortic valve in selected patients with isolated sinus of Valsalva or sinotubular aneurysm and a normal valve provides the advantages of an anticoagulation-free milieu and a more physiological root hemodynamic. The clinical efficacy and durability have been documented. This report describes a simple and reproducible technique of aortic root remodeling that uses a prosthetic conduit as originally pioneered by Magdi Yacoub and later by Tirone David.

Ayurveda recommends many simple herbs in the treatment of urological afflictions like urolithiasis. Seventyone patients diagnosed to be suffering from urolithiasis were treated with juice of the core of the pseudostem of Musa Paradisiaca and Musa sapientum. A significant segment of them passed out calculi of varying size after consuming the drug for two weeks. Recurrence of stone formation was also prevented by the treatment, The author concludes that the plant material is quite effective in curing urolithiasis, especially of the calcium oxalate variety.

Coronary arterial occlusion may occur experimentally during acute myocarditis but has not been documented in man. We report the case of a young female with severe myocarditis who later required cardiac transplantation and in whom coronary occlusion was demonstrated arteriographically before transplantation and by pathological examination of the heart after explantation.