Streamlining the synthesis of amides using Nickel-based nanocatalysts.

The synthesis of amides is a key technology for the preparation of fine and bulk chemicals in industry, as well as the manufacture of a plethora of daily life products. Furthermore, it constitutes a central bond-forming methodology for organic synthesis and provides the basis for the preparation of numerous biomolecules. Here, we present a robust methodology for amide synthesis compared to traditional amidation reactions: the reductive amidation of esters with nitro compounds under additives-free conditions. In the presence of a specific heterogeneous nickel-based catalyst a wide range of amides bearing different functional groups can be selectively prepared in a more step-economy way compared to previous syntheses. The potential value of this protocol is highlighted by the synthesis of drugs, as well as late-stage modifications of bioactive compounds. Based on control experiments, material characterizations, and DFT computations, we suggest metallic nickel and low-valent Ti-species to be crucial factors that makes this direct amide synthesis possible.

A short-term chick embryo in vivo xenograft model to study retinoblastoma cancer stem cells.

Purpose: Cancer stem cells (CSCs) reported in various tumors play a crucial role in tumorigenesis and metastasis of retinoblastoma (Rb). Following the efforts to reduce, replace, and refine the use of mammalian models, we aimed to establish a short-term xenograft for Rb to evaluate the CSC properties of CD133- Rb Y79 cells, using the well-established chick embryo chorioallantoic membrane (CE-CAM) assay. Methods: Y79 cells were cultured, labeled with two different dyes (CM-Dil Y79 and enhanced green fluorescent protein (eGFP)) and sorted for CD133- and CD133 + subsets. Two million cells from each of the labeled groups were transplanted onto the abraded CAM on embryonic day 7 (E7). On E14, the tumor nodule formation on CAM and spontaneous metastasis to the embryos were evaluated by confocal microscopy, in vivo imaging, and histology. Results: Y79 cells formed pink-white raised perivascular nodules with feeder vessels on the CAM with both the types of labeled CD133- cells. CD133- cells, when compared to CD133 + cells, demonstrated significantly larger tumor volume (40.45 ± 7.744 mm3 vs 3.478 ± 0.69 mm3, P = 0.0014) and higher fluorescence intensity (CM-Dil: AUF = 6.37 × 107 ± 7.7 × 106 vs 1.08 × 107 ± 1.6 × 106; P < 0.0001; eGFP: AUF = 13.94 × 104 ± 2.54 × 104 vs AUF = 1.39 × 104 ± 0.4 × 104; P = 0.0003). The metastatic potential of CD133- cells was also observed to be higher as noted by in vivo imaging and histopathology. Conclusion: This study highlights that CE-CAM is a feasible alternative nonmammalian model for evaluating tumorigenicity and metastatic potential of Y79 CSCs. Increased tumorigenicity and metastatic potential of CD133- subset of tumor cells substantiate their CSC properties.

Comparison of hazard models with and without consideration of competing risks to assess the effect of neoadjuvant chemotherapy on locoregional recurrence among breast cancer patients.

CONTEXT: While analyzing locoregional recurrences (LRRs), it is necessary to consider distant metastasis as a competing event. Because, later one is more fatal than LRR. It may change ongoing treatment of breast cancer and may alter the chance of LRR. Although some earlier studies assessed the effect of neoadjuvant chemotherapy (NACT) on LRR, they did not use competing risk regression model for it. AIMS: To identify the risk factors and predict LRR using competing risk hazard model and to compare them with those using conventional hazard model. SETTINGS AND DESIGN: This was a retrospective study from a tertiary care cancer hospital in India. SUBJECTS AND METHODS: Data of 2114 breast cancer patients undergoing surgery were used from patient's record files (1993-2014). STATISTICAL ANALYSIS: Fine and Gray competing risk regression was used to model time from surgery to LRR, considering distant metastasis and death as the competing events. Further, cause-specific Cox regression was used to model time from surgery to LRR without considering competing risk. RESULTS: Greater than ten positive nodes (hazard ratio [HR] [95% confidence interval (CI)]: 2.19 [1.18-4.03]), skin involvement (HR [95% CI]: 2.75 [1.50-5.05]), NACT (HR [95% CI]: 1.90 [1.06-3.40]), invasive tumor in inner quadrant (HR [95% CI]: 1.78 [0.98-3.24]), and postoperative radiotherapy (HR [95% CI]: 0.52 [0.29-0.94]) were found to be significantly associated with LRR. However, conventional survival analysis ignoring competing risk overestimated cumulative incidence function and underestimated survival. Competing risk regression provided relatively more precise CI. Conclusions: Competing risks, if any, need to be incorporated in the survival analysis. NACT was found to be associated with higher risk for LRR, which may be because of administering it mainly to patients with bad prognosis. CONCLUSIONS: Competing risks, if any, need to be incorporated in the survival analysis. NACT was found to be associated with higher risk for LRR, which may be because of administering it mainly to patients with bad prognosis.

Environmental exposure enhances the internalization of microplastic particles into cells.

Microplastic particles ubiquitously found in the environment are ingested by a huge variety of organisms. Subsequently, microplastic particles can translocate from the gastrointestinal tract into the tissues likely by cellular internalization. The reason for cellular internalization is unknown, since this has only been shown for specifically surface-functionalized particles. We show that environmentally exposed microplastic particles were internalized significantly more often than pristine microplastic particles into macrophages. We identified biomolecules forming an eco-corona on the surface of microplastic particles, suggesting that environmental exposure promotes the cellular internalization of microplastics. Our findings further indicate that cellular internalization is a key route by which microplastic particles translocate into tissues, where they may cause toxicological effects that have implications for the environment and human health.

Ultra-small cobalt nanoparticles from molecularly-defined Co-salen complexes for catalytic synthesis of amines.

We report the synthesis of in situ generated cobalt nanoparticles from molecularly defined complexes as efficient and selective catalysts for reductive amination reactions. In the presence of ammonia and hydrogen, cobalt-salen complexes such as cobalt(ii)-N,N'-bis(salicylidene)-1,2-phenylenediamine produce ultra-small (2-4 nm) cobalt-nanoparticles embedded in a carbon-nitrogen framework. The resulting materials constitute stable, reusable and magnetically separable catalysts, which enable the synthesis of linear and branched benzylic, heterocyclic and aliphatic primary amines from carbonyl compounds and ammonia. The isolated nanoparticles also represent excellent catalysts for the synthesis of primary, secondary as well as tertiary amines including biologically relevant N-methyl amines.

Nylon Intermediates from Bio-Based Levulinic Acid.

Use of ZrO2 /SiO2 as a solid acid catalyst in the ring-opening of biobased γ-valerolactone with methanol in the gas phase leads to mixtures of methyl 2-, 3-, and 4-pentenoate (MP) in over 95 % selectivity, containing a surprising 81 % of M4P. This process allows the application of a selective hydroformylation to this mixture to convert M4P into methyl 5-formyl-valerate (M5FV) with 90 % selectivity. The other isomers remain unreacted. Reductive amination of M5FV and ring-closure to ϵ-caprolactam in excellent yield had been reported before. The remaining mixture of 2- and 3-MP was subjected to an isomerising methoxycarbonylation to dimethyl adipate in 91 % yield.

Simple ruthenium-catalyzed reductive amination enables the synthesis of a broad range of primary amines.

The production of primary benzylic and aliphatic amines, which represent essential feedstocks and key intermediates for valuable chemicals, life science molecules and materials, is of central importance. Here, we report the synthesis of this class of amines starting from carbonyl compounds and ammonia by Ru-catalyzed reductive amination using H2. Key to success for this synthesis is the use of a simple RuCl2(PPh3)3 catalyst that empowers the synthesis of >90 various linear and branched benzylic, heterocyclic, and aliphatic amines under industrially viable and scalable conditions. Applying this catalyst, -NH2 moiety has been introduced in functionalized and structurally diverse compounds, steroid derivatives and pharmaceuticals. Noteworthy, the synthetic utility of this Ru-catalyzed amination protocol has been demonstrated by upscaling the reactions up to 10 gram-scale syntheses. Furthermore, in situ NMR studies were performed for the identification of active catalytic species. Based on these studies a mechanism for Ru-catalyzed reductive amination is proposed.

Persistent Mullerian Duct Syndrome with Embryonal Cell Carcinoma along with Ectopic Cross Fused Kidney.

Persistent Mullerian Duct Syndrome (PMDS) is a form of internal male pseudohermaphroditism, where there is normal development of male secondary sexual characters, along with the presence of bilateral fallopian tubes and uterus. Majority of these cases go undetected and some cases are accidentally diagnosed while investigating for other problems. Cross fused renal ectopia is a condition where one kidney lies in the opposite side, fused to the other kidney. We present an extremely rare case of a phenotypical male presenting with mass per abdomen and bilateral cryptorchidism, turned out to have uterus with bilateral fallopian tubes, ectopic cross fused right kidney and Embryonal cell carcinoma of left undescended testis.

Development and validation of highly selective and robust method for simultaneous estimation of pioglitazone, hydroxypioglitazone and metformin in human plasma by LC-MS/MS: application to a pharmacokinetic study.

A simple, selective and robust reverse phase high performance liquid chromatography-electrospray ionization-tandem mass spectrometry (ESI-MS/MS) method for simultaneous quantitation of pioglitazone (PIO), pioglitazone metabolite M-IV - hydroxypioglitazone (OH-PIO) and metformin (MET) in human plasma using deuterated internal standards (IS) is developed and fully validated as per industrial practices. After acetonitrile-induced protein precipitation of the plasma samples; PIO, OH-PIO, MET and IS were chromatographed on reverse phase column and analyzed in the multiple reaction monitoring in positive ion mode. The ion transitions were monitored at m/z 357.2→134.2 for PIO, 373.0→150.1 for OH-PIO, 130.2→71.0 for MET, 361.1→134.2 for PIO-IS and 136.1→77.1 for MET-IS. The total chromatographic run time was 4.0min. A linear response function (r>0.998) was established for the range of concentrations 15-2500ng/mL, 10-1500ng/mL and 25-3000ng/mL for PIO, OH-PIO and MET respectively in human plasma. The intra and inter-day precision and accuracy values have met the set acceptance criteria. The method is simple, selective, robust economic and has been applied successfully to more than 2000 plasma samples as part of pharmacokinetic study in humans.

Insights on chronic-relapsing opsoclonus-myoclonus from a pilot study of mycophenolate mofetil.

Opsoclonus-myoclonus syndrome is characterized by abnormal lymphocyte trafficking into brain. The authors hypothesized that mycophenolate mofetil, a lymphocyte proliferation inhibitor, might be therapeutic. The cerebrospinal fluid and blood immunophenotypes of 15 children with predominantly chronic-relapsing opsoclonus-myoclonus syndrome were compared before and after treatment by flow cytometry. Mycophenolate mofetil reduced the cerebrospinal fluid expansion of HLA-DR+ activated T cells (-40%); the frequency of other T-cell or natural killer cell subsets remained unchanged, but cerebrospinal fluid B cells increased significantly. Adrenocorticotropic hormone dose was lowered by 64% over an average of 1.5 years, yet 73% eventually relapsed despite therapeutic drug levels. Prior treatment with rituximab prevented relapse-associated increase in cerebrospinal fluid B cells, without hindering mycophenolate mofetil-induced reduction in T-cell activation. These data demonstrate resistant immunologic problems in chronic-relapsing opsoclonus-myoclonus syndrome. Mycophenolate mofetil did not prevent relapse. The novel effect of mycophenolate mofetil on chronically activated T cells may contribute to its efficacy in T-cell mediated neurological disorders.

Prevalence of osteoporosis in ambulatory postmenopausal women from a semiurban region in Southern India: relationship to calcium nutrition and vitamin D status.

OBJECTIVE: To assess the prevalence of osteoporosis in healthy ambulatory postmenopausal Indian women as measured by dual-energy x-ray absorptiometry and to study the dietary calcium intake and vitamin D status and their influence on bone mineral density (BMD). METHODS: We conducted a community-based cross-sectional study in a semiurban region. A randomized cluster sampling technique was used. The study cohort consisted of 150 ambulatory postmenopausal women (> or = 50 years old). Dual-energy x-ray absorptiometry for BMD was performed at the lumbar spine and femoral neck. Dietary calcium intake and biochemical variables were assessed. RESULTS: The prevalence of osteoporosis was 48% at the lumbar spine, 16.7% at the femoral neck, and 50% at any site. The mean dietary calcium intake was much lower than the recommended intake for this age-group. There was a significant positive correlation between body mass index and BMD at the lumbar spine and the femoral neck (r = 0.4; P = .0001). BMD at the femoral neck was significantly less (mean, 0.657 versus 0.694 g/cm(2)) in the vitamin D-insufficient study subjects in comparison with the vitamin D-sufficient women (P = .03). CONCLUSION: The high prevalence of osteoporosis and vitamin D insufficiency in this semiurban group of postmenopausal women in India is a major health concern. Measures such as adequate calcium intake and vitamin D supplementation in women of this age-group may be beneficial.

Comparison of MRI pulse sequences in defining prostate volume after permanent implantation.

PURPOSE: To determine the relative value of three MRI pulse sequences in defining the prostate volume after permanent implantation. METHODS AND MATERIALS: A total of 45 patients who received a permanent 125I implant were studied. Two weeks after implantation, an axial CT scan (2 mm thickness) and T1-weighted, T1-weighted fat saturation, and T2-weighted axial MRI (3-mm) studies were obtained. The prostate volumes were compared with the initial ultrasound planning volumes, and subsequently the CT, T1-weighted, and T1-weighted fat saturation MRI volumes were compared with the T2-weighted volumes. Discrepancies in volume were evaluated by visual inspection of the registered axial images and the registration of axial volumes on the sagittal T2-weighted volumes. In a limited set of patients, pre- and postimplant CT and T2-weighted MRI studies were available for comparison to determine whether prostate volume changes after implant were dependent on the imaging modality. RESULTS: T1-weighted and T1-weighted fat saturation MRI and CT prostate volumes were consistently larger than the T2-weighted MRI prostate volumes, with a volume on average 1.33 (SD 0.24) times the T2-weighted volume. This discrepancy was due to the superiority of T2-weighted MRI for prostate definition at the following critical interfaces: membranous urethra, apex, and anterior base-bladder and posterior base-seminal vesicle interfaces. The differences in prostate definition in the anterior base region suggest that the commonly reported underdose may be due to overestimation of the prostate in this region by CT. The consistent difference in volumes suggests that the degree of swelling observed after implantation is in part a function of the imaging modality. In patients with pre- and postimplant CT and T2-weighted MRI images, swelling on the T2-weighted images was 1.1 times baseline and on CT was 1.3 times baseline, confirming the imaging modality dependence of prostate swelling. CONCLUSION: Postimplant T2-weighted MRI images provided superior prostate definition in all critical regions of the prostate compared with CT and the other MRI sequences tested. In addition to defining an optimal technique, these findings call two prior observations into question. Under dosing at the anterior base region may be overestimated because of poor definition of the prostate-bladder muscle interface. The swelling observed after implantation was lower on T2-weighted images as well, suggesting that a fraction of postimplant swelling is a function of the imaging modality. These findings have implications for preimplant planning and postimplant evaluation. As implant planning techniques become more conformal, and registration methods become more efficient, T2-weighted MRI after implantation will improve the accuracy of postimplant dosimetry.

Permanent implantation of 125I sources in the prostate: radical limits of simplicity.

PURPOSE: To determine the effect of reducing the number of sources per implantation on the dose coverage of the prostate volume. MATERIALS AND METHODS: Idealized source distributions were planned for four, eight, 16, 24, 32, and 48 sources. The peripheral loading technique was used to plan a uniform, conformal dose distribution to the target volume, which was the prostate volume as visualized at ultrasonography. Source-placement error was estimated by using measured error magnitudes and was expressed with systematic and random components. The relative sensitivities of the plans to the source-placement error were studied. RESULTS: Idealized planned target coverage can be adequately achieved with comparable dose distributions with eight or more sources. The sensitivity to source-placement error is comparable for plans with 16 or more sources. CONCLUSION: It is theoretically possible to radically simplify implantation without compromising target coverage or error tolerance.

Pulsed brachytherapy: a formalism to account for the variation in dose rate of the stepping source.

Pulsed brachytherapy is an endeavor to mimic low dose rate (LDR) treatments using a single higher activity source (a medium dose rate) that is periodically introduced into the patient (i.e., pulsed) using a remote afterloader. It has been reported that by a careful choice of pulse length and frequency and using the ERD bioeffect dose model, therapeutic advantage (TA) values slightly less than unity can be achieved where TA has been defined as the ratio of tumor ERD for PB to tumor ERD for LDR treatments for constant late-reacting normal tissue ERD. These calculations are based upon a uniform average dose rate in each pulse and equal repair rate constants for both tumor and normal tissue. In this paper, it is demonstrated that TAs of greater than 1 might be possible, depending upon the repair rate constants assumed for the tissues involved. Furthermore, for PB treatments the dose rate at a point of interest during each pulse is not uniform, since the treatment involves a single stepping source. A generalized ERD equation based on the linear quadratic model has been developed to account for the variation in the dose rate and, subsequently, to maximize the TA. Our calculations indicate that PB performed with 40 pulses in 120 hours with an irradiation time of 30 minutes per pulse with a delay time of two and a half hours is the best replacement for a LDR treatment that delivers 60 Gy in 120 hours.

Brachytherapy for the next century: use of image-based treatment planning.

Three-dimensional treatment planning systems used extensively for external-beam treatments have recently been applied for use in brachytherapy. Localization of structures in 3D from imaging studies integrated into computerized systems for planning of implants and evaluation allows 3D dose distributions to be indexed to the patient's anatomy. Correlation of target volume and dose distribution permits planning of conformal dose distributions, which maximizes the dose to the target volume while avoiding dose to normal tissue. Imaging during the implantation process can improve the delivery of the dose distribution planned prior to implantation, which may translate into improved outcome. Postimplant imaging scans can be compared to preimplant planning, providing feedback on the error in source placement and ultimately improving implantation. Application of image-based planning and delivery for ultrasound-guided transperineal prostate implantation is widespread. The first part of this report will discuss in detail a major research effort at our institution to understand and improve the prostate implant process. In the last half of our report, we will describe 3D treatment planning for gynecological implants. Problems with traditional implant planning and delivery procedures (perhaps still used today) and how image-based treatment planning and delivery can improve the implant process will be presented.

Impact of ultrasound and computed tomography prostate volume registration on evaluation of permanent prostate implants.

PURPOSE: Ultrasound (US)-guided permanent prostate implants typically use US prostate volumes to plan the implant procedure and CT prostate volumes for 3D dosimetric evaluation of the implant. Such a protocol requires that CT and US prostate volumes be registered. We have studied the impact of prostate volume registration on postimplant dosimetry for patients with low-grade prostate cancer treated with combined US and fluoroscopic-guided permanent implants. METHODS AND MATERIALS: A US image set was obtained with the patient in the lithotomy position to delineate the prostate volume that was subsequently used for treatment planning. Each plan was customized and optimized to ensure complete coverage of the US prostate volume. After implant, a CT scan was obtained for postimplant dosimetry with the patient lying supine. Sources were localized on CT by interactively creating orthogonal images of small cubes, whose dimensions were slightly larger than the source, to assure unique identification of each seed. Ultrasound and CT 3D surfaces were registered using either (a) the rectal surface and base of the prostate, or (b) the Foley balloon and urethra as the alignment reference. A dose distribution was assigned to the US prostate volume based on the CT source distribution, and the dose-volume histogram (DVH) was calculated. RESULT: Prostate volumes drawn from US images differ from those drawn from CT images with the CT volumes being typically larger than the US volumes. Urethral registration of the prostate volume based on aligning the prostatic urethra generates a dose distribution that best follows the preimplant plan and is geometrically the preferable choice for dosimetry. CONCLUSION: The dose distribution and the DVH for the US prostate is sensitive to the mode of registration limiting the ability to determine if acceptable dose coverage has been achieved.

Impact of differences in ultrasound and computed tomography volumes on treatment planning of permanent prostate implants.

PURPOSE: Both ultrasound (US) and computerized tomography (CT) images have been used in the planning of prostate interstitial therapy. Ultrasound images more clearly define the apex and capsule of the prostate, while CT images define seed positions for postimplant dosimetry. Proper registration of the US volume with the CT volume is critical to the assessment of dosimetry. We therefore compared US and CT prostate volumes to determine if differences were significant. METHODS AND MATERIALS: Ten consecutive patients entered in an interstitial implant program were studied by pretreatment US. In addition, pretreatment CT scans were obtained and three physicians independently outlined the dimensions of the prostate on these images. The patients subsequently underwent placement of radioactive 125I or 103Pd. Postimplant CT images were obtained the next day and the postimplant prostate volumes were outlined by the same three physicians. Seven of 10 patients underwent late CT scans 9-14 months postimplant for comparison of preimplant and immediate postimplant CT studies. RESULTS: There were differences between US and CT volumes. Although the physician-to-physician variation was significant, the trends were consistent, with US prostate volume typically smaller (47%) than the preimplant CT volume and markedly smaller (120%) than the postimplant CT volume. Prostate volumes derived from late CT images did not consistently return to preimplant levels. CONCLUSIONS: Significant differences in volume of the prostate structure were found between US and CT images. The data suggests that: (a) Implants planned on CT tend to overestimate the size of the prostate and may lead to unnecessary implantation of the urogenital diaphragm and penile urethra. (b) Registration of initial US and postimplant CT prostate volumes required for accurate dosimetry is difficult due to the increased volume of prostate secondary to trauma. (c) Further study to determine the optimal time for the postimplant CT is necessary.

Source placement error for permanent implant of the prostate.

The performance of ultrasound (US) and fluoroscopic-guided permanent 125I source implant of the prostate using CT identification of the source positions has been evaluated. Marker seeds were implanted during the planning study to assist in the alignment of the US and CT prostate volumes for treatment planning and to guide the placement of needles. The relative positions of the needles and marker seeds were checked by fluoroscopy. A postimplant CT study was used to input the radioactive source positions and to register the sources relative to the preimplant CT and US prostate volumes and the planned source distribution. Source placement errors observed were categorized as: (1) source-to-source spacing differences; (2) needle placement error, both depth and position; and (3) seed splaying, particularly near the prostate periphery. Errors due to source splaying and spacing were in part attributed to prostate motion. Later refinements included fixed-spaced string sources, for which placement errors were smaller than for unattached sources. However, source placement errors due to needle placement error and prostate motion remained unchanged.

Optimal placement of radioisotopes for permanent prostate implants.

PURPOSE: To determine which of four loading techniques most efficiently yields the prescribed dose to the prostate volume while limiting dose to the central urethral volume. MATERIALS AND METHODS: The four techniques included (a) equal activity and equal spacing with nomogram, (b) differential loading, (c) peripheral loading, and (d) spiked loading of the lobes. They were evaluated with regard to target coverage urethra dose, tolerance to error, and complexity of procedure. RESULTS: All ideal plans delivered the prescribed dose of 160 Gy to 99% of the prostate volume. With prostate-volume expansion and source-placement errors, all strategies indicated that at least 71% of the target volume received the prescribed dose and greater than 92% of the target volume received 120 Gy. CONCLUSION: With source-placement errors and glandular swelling, peripheral loading yields the best target coverage while limiting dose to the central urethral volume.

Crystallization and preliminary structure determination of porcine aldehyde reductase from two crystal forms.

Aldehyde reductase from porcine kidney has been crystallized from buffered ammonium sulfate solutions. Two crystal forms are monoclinic, space group P2(1), with a = 56.2, b = 98.1, c = 73.2 A, beta = 112.5 degrees and a = 92.4, b = 62.1, c = 59.0 A, beta = 94.6 degrees. A third crystal form is hexagonal with a = b = 166.0, c = 66.0 A, alpha = beta = 90.0 degrees and gamma = 120.0 degrees. Molecular-replacement structure solutions have been successfully obtained for the two monoclinic crystal forms. The crystallographic R factor at 8-2.8 A resolution for the two monoclinic crystal forms is currently 0.23 and 0.25, respectively. There are two molecules per asymmetric unit related by a non-crystallographic twofold axis. The aldehyde reductase models are supported by the arrangement of the molecules in their respective unit cells and by electron densities corresponding to amino-acid side chains not included in the search structures.