Silver Complex Bearing N-Heterocyclic Carbene Bidentate Chelating Ligand as an Efficient Catalyst in Solvent-Free KA2 Coupling.

We report a synthesis of silver complexes bearing chelating bidentate N-heterocyclic carbene, with various substitutions at the terminal positions of the imidazole moiety of the NHC units. The long aliphatic substituents proved to be beneficial in terms of the synthetic efficiency of the complexes, compared to previously reported methyl substitution. The complexes demonstrated excellent suitability for the KA2 coupling reaction, providing quaternary carbon-containing propargylic amines in yields up to 95%, under solvent-free conditions. The method showed high tolerance for a wide range of substrates, including naturally occurring ketones, underscoring its practicality. To our knowledge, this represents the first use of a well-defined silver species in KA2 coupling, marking an advancement in the field.

Catalytic Cyclotrimerization Pathway for Synthesis of Selaginpulvilins C and D: Scope and Limitations.

A facile and unified approach to the main selaginpulvilin's framework was achieved by catalytic [2 + 2 + 2]-cyclotrimerization of a triyne with monosubtituted alkynes. The reaction proceeded with high "ortho" selectivity by using Wilkinson's catalyst (RhCl(PPh3)3) under ambient conditions with reasonable yields. The scope of the reaction with respect to the alkyne as well as the catalytic system was evaluated. The formal total modular syntheses of selaginpulvilin C and D were accomplished by transformation of the cyclotrimerization's products.

Dose-response study for the highly aggressive and metastatic primary F3II mammary carcinoma under direct current.

Electrochemical treatment has been suggested as an effective alternative to local cancer therapy. Nevertheless, its effectiveness decreases when highly aggressive primary tumors are treated. The aim of this research was to understand the growth kinetics of the highly aggressive and metastatic primary F3II tumor growing in male and female BALB/c/Cenp mice under electrochemical treatment. Different amounts of electric charge (6, 9, and 18 C) were used. Two electrodes were inserted into the base, perpendicular to the tumor's long axis, keeping about 1 cm distance between them. Results have shown that the F3II tumor is highly sensitive to direct current. The overall effectiveness (complete response + partial response) of this physical agent was ≥75.0% and observed in 59.3% (16/27) of treated F3II tumors. Complete remission of treated tumors was observed in 22.2% (6/27). An unexpected result was the death of 11 direct current-treated animals (eight females and three males). It is concluded that direct current may be addressed to significantly affect highly aggressive and metastatic primary tumor growth kinetics, including the tumor complete response. Bioelectromagnetics. 39:460-475, 2018. © 2018 Wiley Periodicals, Inc.

Is cancer a pure growth curve or does it follow a kinetics of dynamical structural transformation?

BACKGROUND: Unperturbed tumor growth kinetics is one of the more studied cancer topics; however, it is poorly understood. Mathematical modeling is a useful tool to elucidate new mechanisms involved in tumor growth kinetics, which can be relevant to understand cancer genesis and select the most suitable treatment. METHODS: The classical Kolmogorov-Johnson-Mehl-Avrami as well as the modified Kolmogorov-Johnson-Mehl-Avrami models to describe unperturbed fibrosarcoma Sa-37 tumor growth are used and compared with the Gompertz modified and Logistic models. Viable tumor cells (1×105) are inoculated to 28 BALB/c male mice. RESULTS: Modified Gompertz, Logistic, Kolmogorov-Johnson-Mehl-Avrami classical and modified Kolmogorov-Johnson-Mehl-Avrami models fit well to the experimental data and agree with one another. A jump in the time behaviors of the instantaneous slopes of classical and modified Kolmogorov-Johnson-Mehl-Avrami models and high values of these instantaneous slopes at very early stages of tumor growth kinetics are observed. CONCLUSIONS: The modified Kolmogorov-Johnson-Mehl-Avrami equation can be used to describe unperturbed fibrosarcoma Sa-37 tumor growth. It reveals that diffusion-controlled nucleation/growth and impingement mechanisms are involved in tumor growth kinetics. On the other hand, tumor development kinetics reveals dynamical structural transformations rather than a pure growth curve. Tumor fractal property prevails during entire TGK.

Cardiovascular risk factors in pre-pubertal schoolchildren in Angola.

METHODS: The incidence of obesity is increasing worldwide, especially in countries with accelerated economic growth. We determined the prevalence of and associations between overweight/obesity and cardiovascular risk factors in pre-pubertal (seven- to 11-year-old) schoolchildren (both genders, n = 198) in Luanda, Angola. Biochemical (fasting blood) and clinical examinations were obtained in a single visit. Data are reported as prevalence (95% confidence intervals) and association (r, Pearson). RESULTS: Prevalence of overweight/obesity was 17.7% (12.4- 23.0%), high blood pressure (BP > 90% percentile) was 14.6% (9.7-19.5%), elevated glucose level was 16.7% (11.5-21.9%) and total cholesterol level > 170 mg/dl (4.4 mmol/l) was 69.2% (62.8-75.6%). Significant associations between body mass index (BMI) and systolic and diastolic BP (r = 0.46 and 0.40, respectively; p < 0.05) were found. No association between BMI and elevated glucose or cholesterol levels was found. CONCLUSION: The prevalence of cardiovascular risk factors was high in pre-pubertal schoolchildren in Angola and fat accumulation was directly associated with blood pressure increase but not with other cardiovascular risk factors.

3D Stationary electric current density in a spherical tumor treated with low direct current: an analytical solution.

Electrotherapy with direct current delivered through implanted electrodes is used for local control of solid tumors in both preclinical and clinical studies. The aim of this research is to develop a solution method for obtaining a three-dimensional analytical expression for potential and electric current density as functions of direct electric current intensity, differences in conductivities between the tumor and the surrounding healthy tissue, and length, number and polarity of electrodes. The influence of these parameters on electric current density in both media is analyzed. The results show that the electric current density in the tumor is higher than that in the surrounding healthy tissue for any value of these parameters. The conclusion is that the solution method presented in this study is of practical interest because it provides, in a few minutes, a convenient way to visualize in 3D the electric current densities generated by a radial electrode array by means of the adequate selection of direct current intensity, length, number, and polarity of electrodes, and the difference in conductivity between the solid tumor and its surrounding healthy tissue.

Modified Gompertz equation for electrotherapy murine tumor growth kinetics: predictions and new hypotheses.

BACKGROUND: Electrotherapy effectiveness at different doses has been demonstrated in preclinical and clinical studies; however, several aspects that occur in the tumor growth kinetics before and after treatment have not yet been revealed. Mathematical modeling is a useful instrument that can reveal some of these aspects. The aim of this paper is to describe the complete growth kinetics of unperturbed and perturbed tumors through use of the modified Gompertz equation in order to generate useful insight into the mechanisms that underpin this devastating disease. METHODS: The complete tumor growth kinetics for control and treated groups are obtained by interpolation and extrapolation methods with different time steps, using experimental data of fibrosarcoma Sa-37. In the modified Gompertz equation, a delay time is introduced to describe the tumor's natural history before treatment. Different graphical strategies are used in order to reveal new information in the complete kinetics of this tumor type. RESULTS: The first stage of complete tumor growth kinetics is highly non linear. The model, at this stage, shows different aspects that agree with those reported theoretically and experimentally. Tumor reversibility and the proportionality between regions before and after electrotherapy are demonstrated. In tumors that reach partial remission, two antagonistic post-treatment processes are induced, whereas in complete remission, two unknown antitumor mechanisms are induced. CONCLUSION: The modified Gompertz equation is likely to lead to insights within cancer research. Such insights hold promise for increasing our understanding of tumors as self-organizing systems and, the possible existence of phase transitions in tumor growth kinetics, which, in turn, may have significant impacts both on cancer research and on clinical practice.

Primeras experiencias clínicas en Cuba sobre el uso de la electroterapia en cuatro pacientes con tumores sólidos malignos superficiales / First clinical experiences in Cuba with the use of the electrotherapy in four patients with superficial malignant solid tumors

Los primeros estudios clínicos en Cuba fueron realizados para evaluar la seguridad y efectividad de la electroterapia en 4 pacientes con tumor sólido superficial maligno. Se empleó básicamente el equipo chino multifuncional ZAY-6B, en el que además de insertar electrodos en la base perpendicular al eje mayor, se utilizó un arreglo de cátodos y ánodos alternos. Los pacientes fueron cuidadosamente observados durante y después de la sesión con electroterapia para poder evaluar sus efectos terapéuticos. Se obtuvo un retardo significativo del crecimiento tumoral después del tratamiento, particularmente del carcinoma ductal invasor de mama, aunque se logró la remisión parcial de todos los neoplasmas malignos tratados con electricidad. Un hecho interesante fue que las 2 pacientes con carcinoma ductal invasor de mama inoperable, pudieron ser intervenidas quirúrgicamente luego de haber recibido electroterapia.. La necrosis de los 4 tumores malignos se produjo inmediatamente después de la terapia. Transcurridos 8 meses, los hallazgos histopatológicos y peritumorales en el carcinoma ductal invasor de mama de la segunda paciente, revelaron gran necrosis tumoral, congestión vascular, infiltraciones de monocitos y linfocitos y una respuesta inflamatoria crónica. Los resultados preliminares derivados de este adiestramiento indican que la terapia con corriente eléctrica directa de baja intensidad puede ser introducida en el Sistema Nacional de Salud Pública por constituir un método seguro, simple, económico, eficaz, apenas traumático y muy factible para tratar a los pacientes con tumores inoperables en estadios avanzados (III y IV), que no toleran la radioterapia y quimioterapia o en quienes la aplicación de estos métodos oncoespecíficos no proporcionó la respuesta objetiva esperada

Primeras experiencias clínicas en Cuba sobre el uso de la electroterapia en cuatro pacientes con tumores sólidos malignos superficiales / First clinical experiences in Cuba with the use of the electrotherapy in four patients with superficial malignant solid tumors

Los primeros estudios clínicos en Cuba fueron realizados para evaluar la seguridad y efectividad de la electroterapia en 4 pacientes con tumor sólido superficial maligno. Se empleó básicamente el equipo chino multifuncional ZAY-6B, en el que además de insertar electrodos en la base perpendicular al eje mayor, se utilizó un arreglo de cátodos y ánodos alternos. Los pacientes fueron cuidadosamente observados durante y después de la sesión con electroterapia para poder evaluar sus efectos terapéuticos. Se obtuvo un retardo significativo del crecimiento tumoral después del tratamiento, particularmente del carcinoma ductal invasor de mama, aunque se logró la remisión parcial de todos los neoplasmas malignos tratados con electricidad. Un hecho interesante fue que las 2 pacientes con carcinoma ductal invasor de mama inoperable, pudieron ser intervenidas quirúrgicamente luego de haber recibido electroterapia.. La necrosis de los 4 tumores malignos se produjo inmediatamente después de la terapia. Transcurridos 8 meses, los hallazgos histopatológicos y peritumorales en el carcinoma ductal invasor de mama de la segunda paciente, revelaron gran necrosis tumoral, congestión vascular, infiltraciones de monocitos y linfocitos y una respuesta inflamatoria crónica. Los resultados preliminares derivados de este adiestramiento indican que la terapia con corriente eléctrica directa de baja intensidad puede ser introducida en el Sistema Nacional de Salud Pública por constituir un método seguro, simple, económico, eficaz, apenas traumático y muy factible para tratar a los pacientes con tumores inoperables en estadios avanzados (III y IV), que no toleran la radioterapia y quimioterapia o en quienes la aplicación de estos métodos oncoespecíficos no proporcionó la respuesta objetiva esperada