Reducción de metano in vitro con el glucósido cianogénico Linamarina / Reduction of in vitro methane with the cyanogenic glucoside Linamarin

RESUMEN Objetivo. Evaluar el efecto de dosis crecientes del glucósido cianogénico Linamarina, en la reducción de metano ruminal in vitro. Materiales y Métodos. Se empleó líquido ruminal de dos ovejas fistuladas de la raza Merino Precoz, con el que se inoculó un sustrato fermentativo constituido por heno de alfalfa (Medicago sativa) y grano de avena molido (Avena sativa L.), se adicionó solución buffer y Linamarina (pureza de ≥98%) en dosis crecientes, lo que se llevó a incubación por ocho horas in vitro. El metano se midió cada hora, con un monitor de gases infrarrojo. Resultados. De acuerdo con el incremento de las dosis de Linamarina (0, 6, 13, 20 y 26 mg/L), la concentración de metano disminuyó de forma lineal (p≤0.05) en (9.7, 9.2, 18.1 y 29.4%) respectivamente. Se observó una reducción significativa de metano con la dosis más alta de Linamarina. Conclusión. La Linamarina, en su estado puro, fue eficaz en la reducción de metano durante la fermentación ruminal in vitro. Por lo tanto, este estudio constituye una base para futuros experimentos que incluyan fuentes vegetales de Linamarina y otras variables ruminales, lo que puede conducir a encontrar estrategias para reducir los gases de efecto invernadero.

ABSTRACT Objective. To assess the effect of rising doses of the cyanogenic glucoside Linamarin on the reduction of in vitro rumen methane. Materials and methods. Rumen fluid from two fistulated Merino Precoz sheep, inoculated with a fermentation substrate comprising alfalfa hay (Medicago sativa) and ground oat grain (Avena sativa L.), and added with buffer solution and Linamarin (purity ≥98%) in rising doses, was incubated for eight hours in vitro. Methane was measured each hour with an infrared gas monitor. Results. According Linamarin doses were increased (0, 6, 13, 20 and 26 mg/L), the methane concentration fell in a linear manner (p≤0.05) by (9.7, 9.2, 18.1 and 29.4%), respectively. A significant reduction of methane was seen whit the highest dose of Linamarin. Conclusions. Linamarin, in pure state, was effective to reduce methane during in vitro ruminal fermentation. Therefore, this study constitutes a basis for future experiments including vegetable sources of Linamarin as well as other rumen variables, leading to find a strategy for reducing greenhouse gases.

Gold nanoparticles: a revival in precious metal administration to patients.

Gold has been used as a therapeutic agent to treat a wide variety of rheumatic diseases including psoriatic arthritis, juvenile arthritis, and discoid lupus erythematosus. Although the use of gold has been largely superseded by newer drugs, gold nanoparticles are being used effectively in laboratory based clinical diagnostic methods while concurrently showing great promise in vivo either as a diagnostic imaging agent or a therapeutic agent. For these reasons, gold nanoparticles are therefore well placed to enter mainstream clinical practice in the near future. Hence, the present review summarizes the chemistry, pharmacokinetics, biodistribution, metabolism, and toxicity of bulk gold in humans based on decades of clinical observation and experiments in which gold was used to treat patients with rheumatoid arthritis. The beneficial attributes of gold nanoparticles, such as their ease of synthesis, functionalization, and shape control are also highlighted demonstrating why gold nanoparticles are an attractive target for further development and optimization. The importance of controlling the size and shape of gold nanoparticles to minimize any potential toxic side effects is also discussed.

Noninvasive Raman spectroscopy in living mice for evaluation of tumor targeting with carbon nanotubes.

An optimized noninvasive Raman microscope was used to evaluate tumor targeting and localization of single walled carbon nanotubes (SWNTs) in mice. Raman images were acquired in two groups of tumor-bearing mice. The control group received plain-SWNTs, whereas the experimental group received tumor targeting RGD-SWNTs intravenously. Raman imaging commenced over the next 72 h and revealed increased accumulation of RGD-SWNTs in tumor ( p < 0.05) as opposed to plain-SWNTs. These results support the development of a new preclinical Raman imager.

Noninvasive molecular imaging of small living subjects using Raman spectroscopy.

Molecular imaging of living subjects continues to rapidly evolve with bioluminescence and fluorescence strategies, in particular being frequently used for small-animal models. This article presents noninvasive deep-tissue molecular images in a living subject with the use of Raman spectroscopy. We describe a strategy for small-animal optical imaging based on Raman spectroscopy and Raman nanoparticles. Surface-enhanced Raman scattering nanoparticles and single-wall carbon nanotubes were used to demonstrate whole-body Raman imaging, nanoparticle pharmacokinetics, multiplexing, and in vivo tumor targeting, using an imaging system adapted for small-animal Raman imaging. The imaging modality reported here holds significant potential as a strategy for biomedical imaging of living subjects.

Characterization of an intraperitoneal ovarian cancer xenograft model in nude rats using noninvasive microPET imaging.

MicroPET is a noninvasive imaging modality that can potentially track tumor development in nude rats using the radiotracer fluorine 18-fluorodeoxyglucose ((18)F-FDG). Our goal was to determine whether microPET, as opposed to more invasive techniques, could be used to noninvasively monitor the development of ovarian cancer in the peritoneal cavity of nude rats for monitoring treatment response in future studies. Female nude rats were inoculated intraperitoneally with 36 million NIH:OVCAR-3 cells. Imaging was carried out at 2, 4, 6, or 8 weeks postinoculation. Each rat was fasted overnight and intravenously injected with 11.1 MBq (300 microCi) of (18)F-FDG in 0.2 mL of saline. Thirty minutes following injection, the rats were placed in the microPET and scanned for 30 min. After imaging, rats were euthanized for ascites and tissue collection for biodistribution and histopathologic correlation. Standard uptake values (SUVs) of (18)F-FDG within the peritoneal cavity were also calculated from regions of interest analysis of the microPET images. MicroPET images showed diffuse increased uptake of (18)F-FDG throughout the peritoneal cavity of tumor rats (mean SUV=4.64) compared with control rats (mean SUV=1.03). Ascites gathered from tumor-bearing rats had increased (18)F-FDG uptake as opposed to the peritoneal fluid collected from control rats. Biodistribution data revealed that the percent injected dose per gram (% ID/g) was significantly higher in tumor-bearing rats (6.29%) than in control rats (0.59%) in the peritoneal lymph nodes. Pathology verified that these lymph nodes were more reactive in tumor-bearing rats. By 6 weeks, some rats developed solid masses within the peritoneum, which could be detected on microPET images and confirmed as tumor by histopathology. (18)F-FDG uptake in these tumors at necropsy was 2.83% ID/g. These results correlate with previous invasive laparoscopic studies of the same tumor model and demonstrate that microPET using (18)F-FDG is a promising noninvasive tool to localize and follow tumor growth in an intraperitoneal ovarian cancer model.

Training surgeons in endoscopic retrograde cholangiopancreatography.

BACKGROUND: General surgeons commonly perform upper gastrointestinal endoscopy in practice, but few perform endoscopic retrograde cholangiopancreatography (ERCP), partly because of limited training opportunities. This report focuses on the value of an ERCP fellowship training program to a broad-based, mature residency in surgery and our observations on the experience required for surgeons to be trained in advanced interventional ERCP. METHODS: Since the program was initiated in 1992, 13 ERCP fellows have been trained for individual periods of 6 to 14 months. This study investigated all procedures with fellow involvement (2,008 cases) from among a total experience of 3,641 ERCPs. Data collected included type of ERCP (diagnostic/therapeutic), fellow success in cannulating the duct of interest, and faculty success in cases of fellows who failed. Of the 13 fellows, 9 had previous endoscopy experience, but none had training in ERCP. RESULTS: An 85% cannulation rate was accepted as successful, and cannulation rates for each fellow were calculated for each 3-month period. The 85% mark was reached by 4 (31%) of 13 fellows in the first period, 2 of 13 fellows (15%) in the second period, 5 of 11 fellows (45%) in the third period, 7 of 10 fellows (70%) in the fourth period, and 1 of 1 fellow (100%) in the fifth period of training. On the average, it took 7.1 months and 102 ERCPs for trainees to reach desired success levels. Success came more promptly with prior exposure to endoscopy. Fellows without prior endoscopic experience required 148 cases to reach 85% success. Resident surgical experience with major pancreatic resections increased threefold after establishment of the fellowship. CONCLUSIONS: Training in ERCP is possible within the scope of a surgical fellowship in a reasonable length of time and experience. Complication rates remain low even with fellow involvement. Establishment of an ERCP program increases the focus and experience of pancreas surgery in a surgical residency for chief residents.

Role of pancreatic duct stenting in the treatment of chronic pancreatitis.

BACKGROUND: Endoscopic retrograde cholangiopancreatography and stent placement are relatively new alternatives to surgery for the treatment of chronic pancreatitis. The objective of this study was to determine the efficacy of pancreatic duct stent placement for the treatment of chronic pancreatitis. METHODS: This study included 89 patients treated with pancreatic stents between 1993 and 2002. The patients were contacted via telephone for a personal interview with regard to pain, medication usage, weight loss or gain, and eating patterns. Additionally, medication usage before and after treatment was documented from the Kentucky Cabinet for Health Services' electronic reporting system for narcotic use. RESULTS: Of the 89 patients, 9 were deceased, 5 either refused to interview or could not be contacted, and 75 were interviewed. Significant weight gain exceeding 15 lb after treatment was experienced by 22%, whereas only 4% lost weight. A majority of the patients (68%) noted that they had less severe relapses or no relapses after treatment. The patients reported a decrease in pain level on a 10-point scale from 8.7 to 4.1 (53% decrease) after treatment. A decrease in pain medication usage was reported by 47% of the patients, and 83% considered their treatment successful. The Kentucky All Schedule Prescription Electronic Report (KASPER) was obtained before and after treatment for 55 patients. According to this statewide electronic reporting system, 63% had a documented decrease in narcotic use. CONCLUSION: The findings of this study support the use of pancreatic duct stenting as an option before surgical intervention for these difficult-to-manage patients with chronic pancreatitis.

Cáncer después de cáncer de mama / Cancer after breast cancer

En México, el cáncer de mama es la segunda neoplasia más frecuente en la mujer y el primero en países como Estados Unidos de Norteamérica e Israel. La aparición de un segundo tumor primario es poco común (4-9 por ciento) y surge en la mama contralateral, ovario, tiroides y piel. De enero de 1976 a diciembre de 1996, en estudio retrospectivo se incluyeron pacientes del Hospital General de México y del Hospital ABC con diagnóstico histopatológico de cáncer de mama. Se estableció la frecuencia de segundas neoplasias primarias; tiempo global de sobrevida y factores clínicos pronósticos. El resultado de los 363 casos es el siguiente; fueron detectados 15 (4.1 por ciento) con segundas neoplasias primarias; se diagnóstico cáncer de mama contralateral en ocho pacientes y siete tumores no mamarios; dos de pulmón, dos de endometrio, dos de tiroides y uno de ovario; el tiempo de sobrevida fue de 38 meses. Se encontró bajo el riesgo en mujeres con cáncer de mama para desarrollar una segunda neoplasia primaria. Esta nueva aparición no mostró relación con la edad ni con la modalidad terapéutica utilizada

Study of a new analgesic compound in the treatment of tension headache.

The effect of a new analgesic compound (propoxyphene, acetaminophen, caffeine, hydroxyzine) was investigated in a single-blind study comparing it with plain acetaminophen administered to forty patients with tension headache. For the study, patients were assigned to one of two groups of twenty each. Starting dose for each group was one to two tablets followed by one tablet every four to six hours. The results show that 90% clinical success was obtained with the analgesic compound, while a 45% success was obtained with plain acetaminophen. This is a statistically significant difference. Side-effects observed with analgesic compound were primarily drowsiness and dizziness of mild intensity; acetaminophen caused gastro-intestinal alterations (nausea, vomiting) and dizziness of greater severity. Therapy was withdrawn in 20% of patients taking acetaminophen because of side-effects. The dosage of analgesic compound required to control each episode of tension headache was smaller than that of acetaminophen. These results can be explained by a possible potentiation of pharmacological activity of the compound's components. It can be concluded that the analgesic compound is a new and effective combination for the symptomatic treatment of tension headache.