Cumulative Incidence and Risk Factors of Permanent Stoma After Intersphincteric Resection for Ultralow Rectal Cancer.

BACKGROUND: A permanent stoma is an unintended consequence that cannot be avoided completely after intersphincteric resection for ultralow rectal cancer. Unfortunately, its incidence and risk factors have been poorly defined. OBJECTIVE: The objective was to determine the cumulative incidence and risk factors of permanent stoma after intersphincteric resection for ultralow rectal cancer. DESIGN: This study was a retrospective analysis of prospectively collected data. SETTINGS: This study was conducted at a colorectal surgery referral center. PATIENTS: A total of 185 consecutive patients who underwent intersphincteric resection with diverting ileostomy from 2011 to 2019 were included. MAIN OUTCOME MEASURES: The primary outcome was the incidence of and risk factors for the permanent stoma. The secondary outcome included differences in stoma formation between patients with partial, subtotal, and total intersphincteric resection. RESULTS: After a median follow-up of 40 months (range, 6-107 months), 26 of 185 patients eventually required a permanent stoma, accounting for a 5-year cumulative incidence of 17.4%. The causes of permanent stoma were anastomotic morbidity (46.2%, 12/26), local recurrence (19.2%, 5/26), distant metastasis (19.2%, 5/26), fecal incontinence (3.8%, 1/26), perioperative mortality (3.8%, 1/26), patients' refusal (3.8%, 1/26), and poor general condition (3.8%, 1/26). Although the incidence of permanent stoma was significantly different between the intersphincteric resection groups (partial vs subtotal vs total: 8.3% vs 20% vs 25.8%, p = 0.02), it was not an independent predictor of stoma formation. Multivariate analysis demonstrated that anastomotic leakage (OR = 5.29; p = 0.001) and anastomotic stricture (OR = 5.13; p = 0.002) were independently predictive of permanent stoma. LIMITATIONS: This study was limited by its retrospective nature and single-center data. CONCLUSIONS: The 5-year cumulative incidence of permanent stoma was 17.4%. Anastomotic complications were identified as risk factors. Patients should be informed of the risks and benefits when contemplating the ultimate sphincter-sparing surgery. It might be preferable to decrease the probability of permanent stoma by further minimizing anastomotic complications. See Video Abstract at http://links.lww.com/DCR/B704. INCIDENCIA ACUMULADA Y FACTORES DE RIESGO DE ESTOMA PERMANENTE DESPUS DE UNA RESECCIN INTERESFNTRICA EN CNCER RECTAL ULTRA BAJO: ANTECEDENTES:La necesidad de efectuar un estoma permanente es la consecuencia no intencional e inevitable por completo después de una resección interesfintérica en presencia de un cáncer rectal ultra bajo. Desafortunadamente, la incidencia y los factores de riesgo se han definido en una forma limitada.OBJETIVO:El objetivo fue determinar la incidencia acumulada y los factores de riesgo para la necesidad de efectuar un estoma permanente después de la resección intersfintérica de un cáncer rectal ultra bajo.DISEÑO:El presente estudio es un análisis retrospectivo de la información obtenida.ESCENARIO:Centro de referencia de cirugía colo-rectal.PACIENTES:Se incluyeron un total de 185 pacientes consecutivos que se sometieron a resección intersfintérica de un cáncer rectal ultra bajo con ileostomía de derivación de 2011 a 2019.MEDICION DE RESULTADOS:El resultado principal fue la identificación de la incidencia y los factores de riesgo para la presencia de un estoma permanente. En forma secundaria se describieron los resultados de las diferentes técnicas de la formación de un estoma entre los pacientes con resección interesfintérica parcial, subtotal o total.RESULTADOS:Posterior a una media de seguimiento de cuarenta meses (rango de 6 a 107), 26 de 185 pacientes requirieron en forma eventual un estoma permanente, lo que equivale a una incidencia acumulada a cinco años de 17.4 %. Las causas para dejar un estoma permanente fueron morbilidad de la anastomosis (46.2%, 12/26), recurrencia local (19.2%, 5/26), metástasis a distancia (19.2%, 5/26), incontinencia fecal (3.8%, 1/26), mortalidad perioperatoria (3.8%, 1/26), rechazo del paciente (3.8%, 1/26), y malas condiciones generales (3.8%, 1/26). Aunque la incidencia de un estoma permanente fue significativamente diferente entre los grupos de resección interesfintérica (parcial vs subtotal vs total: 8.3% vs 20% vs 25.8%, p = 0.02), no se consideró un factor predictor independiente para la formación de estoma. En el análisis multivariado se demostró que la fuga anatomótica (OR = 5.29; p = 0.001) y la estenosis anastomótica (OR = 5.13; p = 0.002) fueron factores independientes para predecir la necesidad de un estoma permanente.LIMITACIONES:La naturaleza retrospectiva del estudio y la información proveniente de un solo centro.CONCLUSIONES:La incidencia acumulada a cinco años de estoma permantente fue de 17.4%. Se consideran a las complicaciones anastomóticas como factores de riesgo. Los pacientes deberán ser informados de los riesgos y beneficios cuando se considere la posibilidad de efectuar una cirugía preservadora de esfínteres finalmente. Puede ser preferible disminuir la probabilidad de dejar un estoma permanente tratando de minimizar la posibilidad de complicaciones de la anastomosis. Consulte Video Resumen en http://links.lww.com/DCR/B704.

A universal quantification of transgenic soybean event DAS-68416-4 using duplex digital PCR.

BACKGROUND: As labeling thresholds and low level presence thresholds of genetically modified (GM) components are implemented in more and more countries and regions, the demands for accurate quantification are increasing rapidly. At the same time, digital polymerase chain reaction (PCR) showed considerable benefits compared with former real-time fluorescence PCR in GM component quantification. RESULTS: A universal quantification method using duplex digital PCR was established for detection of transgenic soybean event DAS-68416-4. The absolute limits of quantification (LOQs) of DAS-68416-4 event-specific gene and lectin reference gene were 0.61 copies µL-1 and 4.6 copies µL-1 respectively in droplet digital PCR, while 0.522 copies µL-1 and 5.192 copies µL-1 in chip digital PCR. The relative LOQs of DAS-68416-4 percentage content was 0.1% in both two digital PCR systems. CONCLUSION: Gene copy ratio is the universal means of expression internationally used in transgenic component contents. Digital polymerase chain reaction (PCR) executes absolute quantification on specific genes, thus is considered to be suitable for detection of transgenic component contents. It was proved in this research on transgenic soybean event DAS-68416-4. Results indicated perfect satisfaction for transgenic component quantification needs in various technical performances of duplex digital PCR including repeatability, quantitative linear relationship and relative limits of quantification. © 2020 Society of Chemical Industry.

Injectable Drug-Releasing Microporous Annealed Particle Scaffolds for Treating Myocardial Infarction.

Intramyocardial injection of hydrogels offers great potential for treating myocardial infarction (MI) in a minimally invasive manner. However, traditional bulk hydrogels generally lack microporous structures to support rapid tissue ingrowth and biochemical signals to prevent fibrotic remodeling toward heart failure. To address such challenges, a novel drug-releasing microporous annealed particle (drugMAP) system is developed by encapsulating hydrophobic drug-loaded nanoparticles into microgel building blocks via microfluidic manufacturing. By modulating nanoparticle hydrophilicity and pregel solution viscosity, drugMAP building blocks are generated with consistent and homogeneous encapsulation of nanoparticles. In addition, the complementary effects of forskolin (F) and Repsox (R) on the functional modulations of cardiomyocytes, fibroblasts, and endothelial cells in vitro are demonstrated. After that, both hydrophobic drugs (F and R) are loaded into drugMAP to generate FR/drugMAP for MI therapy in a rat model. The intramyocardial injection of MAP gel improves left ventricular functions, which are further enhanced by FR/drugMAP treatment with increased angiogenesis and reduced fibrosis and inflammatory response. This drugMAP platform represents a new generation of microgel particles for MI therapy and will have broad applications in regenerative medicine and disease therapy.

Apoptosis and injuries of heavy ion beam and x-ray radiation on malignant melanoma cell.

This study aims to investigate the influence of high linear energy transfer (LET) heavy ion (12C6+) and low LET X-ray radiation on apoptosis and related proteins of malignant melanoma on tumor-bearing mice under the same physical dosage. C57BL/6 J mice were burdened by tumors and randomized into three groups. These mice received heavy ion (12C6+) and X-ray radiation under the same physical dosage, respectively; their weight and tumor volumes were measured every three days post-radiation. After 30 days, these mice were sacrificed. Then, median survival time was calculated and tumors on mice were proliferated. In addition, immunohistochemistry was carried out for apoptosis-related proteins to reflect the expression level. After tumor-bearing mice were radiated to heavy ion, median survival time improved and tumor volume significantly decreased in conjunction with the upregulated expression of pro-apoptosis factors, Bax and cytochrome C, and the downregulated expression of apoptosis-profilin (Bcl-2, Survivin) and proliferation-related proteins (proliferating cell nuclear antigen). The results indicated that radiation can promote the apoptosis of malignant melanoma cells and inhibit their proliferation. This case was more suitable for heavy ion (12C6+). High LET heavy ion (12C6+) radiation could significantly improve the killing ability for malignant melanoma cells by inducing apoptosis in tumor cells and inhibiting their proliferation. These results demonstrated that heavy ion (12C6+) presented special advantages in terms of treating malignant melanoma. Impact statement Malignant melanoma is a malignant skin tumor derived from melanin cells, which has a high malignant degree and high fatality rate. In this study, proliferating cell nuclear antigen (PCNA) can induce the apoptosis of malignant melanoma cells and inhibit its proliferation, and its induction effect on apoptosis is significantly higher than low LET X-ray; hence, it is expected to overcome its lower sensitivity to radiation. This study can provide theoretical basis for clinical trials, in which malignant melanoma is treated by heavy ion (12C6+), in order to accurately determine the clinical efficacy of heavy ion therapy. Clinical applications has revealed that local tumor control rate is high when heavy ion is used to treat malignant melanoma, indicating that heavy ion is an important direction in treating melanoma in the future.

In vivo comparison of tantalum, tungsten, and bismuth enteric contrast agents to complement intravenous iodine for double-contrast dual-energy CT of the bowel.

To assess the ability of dual-energy CT (DECT) to separate intravenous contrast of bowel wall from intraluminal contrast, we scanned 16 rabbits on a clinical DECT scanner: n = 3 using only iodinated intravenous contrast, and n = 13 double-contrast enhanced scans using iodinated intravenous contrast and experimental enteric non-iodinated contrast agents in the bowel lumen (five bismuth, four tungsten, and four tantalum based). Representative image pairs from conventional CT images and DECT iodine density maps of small bowel (116 pairs from 232 images) were viewed by four abdominal imaging attending radiologists to independently score each comparison pair on a visual analog scale (-100 to +100%) for (1) preference in small bowel wall visualization and (2) preference in completeness of intraluminal enteric contrast subtraction. Median small bowel wall visualization was scored 39 and 42 percentage points (95% CI 30-44% and 36-45%, both p < 0.001) higher for double-contrast DECT than for conventional CT with enteric tungsten and tantalum contrast, respectively. Median small bowel wall visualization for double-contrast DECT was scored 29 and 35 percentage points (95% CI 20-35% and 33-39%, both p < 0.001) higher with enteric tungsten and tantalum, respectively, than with bismuth contrast. Median completeness of intraluminal enteric contrast subtraction in double-contrast DECT iodine density maps was scored 28 and 29 percentage points (95% CI 15-31% and 28-33%, both p < 0.001) higher with enteric tungsten and tantalum, respectively, than with bismuth contrast. Results suggest that in vivo double-contrast DECT with iodinated intravenous and either tantalum- or tungsten-based enteric contrast provides better visualization of small bowel than conventional CT. Copyright © 2016 John Wiley & Sons, Ltd.

Extravasated contrast material in penetrating abdominopelvic trauma: dual-contrast dual-energy CT for improved diagnosis--preliminary results in an animal model.

PURPOSE: To compare the diagnostic performance of dual-energy (DE) computed tomography (CT) with two simultaneously administered contrast agents (hereafter, dual contrast) with that of conventional CT in the evaluation of the presence and source of extravasation in penetrating abdominopelvic trauma. MATERIALS AND METHODS: Institutional animal care and use committee approval was obtained, and the study was performed in accordance with National Institutes of Health guidelines for the care and use of laboratory animals. Five rabbits with bowel trauma, vascular penetrating trauma, or both were imaged with simultaneous iodinated intravenous and bismuth subsalicylate enteric contrast material at DE CT. Four attending radiologists and six radiology residents without prior DE CT experience each evaluated 10 extraluminal collections to identify the vascular and/or enteric origin of extravasation and assess their level of diagnostic confidence, first with virtual monochromatic images simulating conventional CT and then with DE CT material decomposition attenuation maps. RESULTS: Overall accuracy of identification of source of extravasation increased from 78% with conventional CT to 92% with DE CT (157 of 200 diagnoses vs 184 of 200 diagnoses, respectively; P < .001). Nine radiologists were more accurate with DE CT; one had no change. Mean confidence increased from 67% to 81% with DE CT (P < .001). CONCLUSION: In a rabbit abdominopelvic trauma model, dual-contrast DE CT significantly increased accuracy and confidence in the diagnosis of vascular versus enteric extravasated contrast material.

Expression of HGF and Met in human tissues of colorectal cancers: biological and clinical implications for synchronous liver metastasis.

BACKGROUND AND AIMS: Synchronous liver metastasis (SLM) remains a significant problem in newly diagnosed colorectal cancer (CRC). The system of hepatocyte growth factor (HGF) and Met plays an important role in cancer invasion and metastasis and is being developed to be targeted drugs. We aimed to investigate the role of HGF/Met in SLM based on a case-matched study and comparison between primary tumors and matched metastases. METHODS: A group of 30 patients with SLM and other two groups of patients without SLM in a hospital database were collected. They were matched into according to clinicopathological factors. 81 patients were included in the study. Their tissues of primary colorectal cancers, lymph nodes and liver metastases were collected to detect HGF and Met expression by immunohistochemistry and RT-PCR. RESULTS: Expression of HGF and Met at the protein level and the RNA level in primary CRCs with SLM were significantly higher than that in primary colorectal carcinomas without liver metastases (all P value<0.05). Their expression was only related to SLM when concurrent with regional lymph node metastasis (all P value<0.05) but had little influence on SLM without involvement of lymph node metastasis (all P value>0.05). Comparison their expression between primary tumors and matched metastases, major concordance and minor difference existed. CONCLUSIONS: HGF and Met may exert functions in the development of SLM when concurrent with lymph node metastases but had little influence on SLM without lymph node metastasis, further indicating their roles and potential values for a subtype of colorectal cancer metastasis. Major concordance and minor difference exist between primary tumors and matched metastases, which further provides evidence for evaluating the response to their inhibitors based on primary tumors or metastases.

In vivo differentiation of complementary contrast media at dual-energy CT.

PURPOSE: To evaluate the feasibility of using a commercially available clinical dual-energy computed tomographic (CT) scanner to differentiate the in vivo enhancement due to two simultaneously administered contrast media with complementary x-ray attenuation ratios. MATERIALS AND METHODS: Approval from the institutional animal care and use committee was obtained, and National Institutes of Health guidelines for the care and use of laboratory animals were observed. Dual-energy CT was performed in a set of iodine and tungsten solution phantoms and in a rabbit in which iodinated intravenous and bismuth subsalicylate oral contrast media were administered. In addition, a second rabbit was studied after intravenous administration of iodinated and tungsten cluster contrast media. Images were processed to produce virtual monochromatic images that simulated the appearance of conventional single-energy scans, as well as material decomposition images that separate the attenuation due to each contrast medium. RESULTS: Clear separation of each of the contrast media pairs was seen in the phantom and in both in vivo animal models. Separation of bowel lumen from vascular contrast medium allowed visualization of bowel wall enhancement that was obscured by intraluminal bowel contrast medium on conventional CT scans. Separation of two vascular contrast media in different vascular phases enabled acquisition of a perfectly coregistered CT angiogram and venous phase-enhanced CT scan simultaneously in a single examination. CONCLUSION: Commercially available clinical dual-energy CT scanners can help differentiate the enhancement of selected pairs of complementary contrast media in vivo.

Approach to assessing myocardial perfusion in rats using static [13N]-ammonia images and a small-animal PET.

PURPOSE: Semi-quantitative, static positron emission tomography (PET) has been used to perform an initial approach to the assessment of [13N]-ammonia perfusion studies aimed to elucidating the effect of injecting human embryonic stem cell-derived (hES) hemangioblasts on infarcted rat hearts. PROCEDURES: Female NIH nude rats underwent occlusion of the left anterior descending coronary artery for 30 min before reperfusion. Either one million hES-derived hemangioblasts (n = 5) or control media (n = 4) were injected into the site of the infarct 1 day post-myocardial infarction (MI) under high-resolution echocardiography guidance. PET imaging was performed 6 weeks after MI induction, and uptake polar maps were created by sampling the left ventricle at equidistant slices from the base to the apex and measuring the average myocardium value at three contiguous voxels to minimize partial volume effects. Statistical comparison between treatment and control groups was done with a Mann-Whitney U test. RESULTS: Myocardium uptake ratios for treated and untreated subjects show statistically significant difference (98% certainty). CONCLUSIONS: The straightforward procedure described here (similar to those commonly used in clinical routine) was sufficient to yield statistically significant perfusion differences between the treated and untreated animals despite the small sample size.

Biodistributions of 177Lu- and 111In-labeled 7E11 antibodies to prostate-specific membrane antigen in xenograft model of prostate cancer and potential use of 111In-7E11 as a pre-therapeutic agent for 177Lu-7E11 radioimmunotherapy.

INTRODUCTION: Prostate-specific membrane antigen is a transmembrane glycoprotein highly expressed in many prostate cancers and can be targeted with radiolabeled antibodies for diagnosis and treatment of this disease. To serve as a radioimmunotherapeutic agent, a kinetically inert conjugate is desired to maximize tumor uptake and tumor radiation dose with minimal nonspecific exposure to bone marrow and other major organs. MATERIALS AND METHODS: In this study, we assessed the pharmacokinetics and biodistribution of the 7E11 monoclonal antibody (MAb) radiolabeled with the lutetium-177 ((177)Lu)-tetraazacyclododecanetetraacetic acid conjugate system ((177)Lu-7E11) versus those of the 7E11 MAb radiolabeled with the indium-111 ((111)In)/glycyl-tyrosyl-(N,-diethylenetriaminepentaacetic acid)/lysine hydrochloride conjugate system ((111)In-7E11, also known as ProstaScint) to determine the feasibility of using (111)In-7E11 as a pre-therapeutic agent for (177)Lu-7E11 radioimmunotherapy. Pharmacokinetic and biodistribution studies of (177)Lu-7E11 in lymph node cancer of the prostate (LNCaP) xenograft mice were performed at 2, 8, 12, 24, 72, and 168 h after radiopharmaceutical administration. For (111)In-7E11, pharmacokinetic and biodistribution studies were performed at 8, 24, and 72 h. Parallel studies of (177)Lu-7E11 in non-tumor-bearing mice at 8, 24, and 72 h post-injection served as controls. Gamma scintigraphy was performed, followed by autoradiography and tissue counting, to demonstrate and quantify the distributions of radioconjugated MAb in the tumor and normal tissues. RESULTS AND DISCUSSION: Both (177)Lu- and (111)In-7E11 conjugates demonstrated an early blood pool phase in which uptake was dominated by the blood, lung, spleen and liver, followed by uptake and retention of the radiolabeled antibody in the tumor which was most prominent at 24 h. Total accumulation of radioconjugated MAb in tumor at 24 h was greater in the case of (177)Lu-7E11 in comparison to that of (111)In-7E11. Continued accumulation in tumor was observed for the entire time course studied for both (177)Lu-7E11 and (111)In-7E11. The liver was the only major organ demonstrating a significant difference in accumulation between the two conjugates. In conclusion, pharmacokinetic and biodistribution studies of (177)Lu-7E11 in LNCaP xenograft mouse models support its potential application as a radioimmunotherapeutic agent targeting prostate cancer, and the distribution and tumor uptake of (111)In-7E11 appear to be similar to those of (177)Lu-7E11, supporting its use as a pre-therapeutic tool to assess the potential accumulation of (177)Lu-7E11 radioimmunotherapeutic at sites of prostate cancer. However, the different accumulation patterns of the (111)In and (177)Lu immunoconjugates in liver will likely prevent the use of (111)In-7E11 as a true dosimetry tool for (177)Lu-7E11 radioimmunotherapy.

In vivo imaging of mucosal CD4+ T cells using single photon emission computed tomography in a murine model of colitis.

Immune responses that occur in the context of human infectious and inflammatory diseases are usually studied by sampling cells from peripheral blood, from biopsies, or by end-point harvests at necropsy. These approaches are likely to yield information that is incomplete and/or non-representative. Here, we report the development and validation of a non-invasive method to localize and to quantitate the disposition of specific subpopulations of cells in vivo. In a murine model of dextran sulfate sodium (DSS)-induced colitis, CD4+ T cells were visualized in the colon by single photon emission computed tomography (SPECT-CT) after injection of monoclonal, non-depleting, indium-111 (111In) labeled anti-CD4+ antibodies. The SPECT-CT colon uptake ratio (CUR) was found to correlate (p<0.01) with the number of total CD4+ T cells and with standard measures of pathology (colon length, cell counts, and histopathologic evidence of apoptosis, edema, and cellular infiltrates) as assessed by direct examination of diseased colon. Each of these parameters, including the SPECT-CT signal uptake, increased as a function of DSS dose (p<0.05). We conclude that CT-SPECT imaging using an 111In-labeled anti-CD4+ antibody is reflective of traditional parameters of pathology in this experimental model of murine colitis. This approach should be readily applicable to the imaging of discrete cell subpopulations in non-human primates and in humans, thus augmenting our understanding of infectious diseases and inflammation in vivo.

Telomeric transgenes are silenced in adult mouse tissues and embryo fibroblasts but are expressed in embryonic stem cells.

In addition to their role in protecting the ends of chromosomes, telomeres also influence the expression of adjacent genes, a process called telomere-position effect. We previously reported that the neo and HSV-tk transgenes located adjacent to telomeres in mouse embryonic stem cells are initially expressed at low levels and then become gradually silenced upon passage in culture through a process involving DNA methylation. We also reported extensive DNA methylation in these telomeric transgenes in three different tissues isolated from mice generated from one of these embryonic stem cell clones. In the present study, we demonstrate that embryo fibroblasts isolated from two different mouse strains show extensive DNA methylation and silencing of the telomeric transgenes. Consistent with this observation, we also demonstrate little or no detectable expression of the HSV-tk telomeric transgene in somatic tissues using whole body imaging. In contrast, both telomeric transgenes are expressed at low levels and have little DNA methylation in embryonic stem cell lines isolated from these same mouse strains. Our results demonstrate that telomere-position effect in mammalian cells can be observed either as a low level of expression in embryonic stem cells in the preimplantation embryo or as complete silencing and DNA methylation in differentiated cells and somatic tissues. This pattern of expression of the telomeric transgenes demonstrates that subtelomeric regions, like much of the genome, are epigenetically reprogrammed in the preimplantation embryo, a process that has been proposed to be important in early embryonic development. Disclosure of potential conflicts of interest is found at the end of this article.

Rodent brain imaging with SPECT/CT.

We evaluated methods of imaging rat models of stroke in vivo using a single photon emission computed tomography (SPECT) system dedicated to small animal imaging (X-SPECT, Gamma Medica-Ideas, Northridge, CA). An animal model of ischemic stroke was developed for in vivo SPECT/CT imaging using the middle cerebral artery occlusion (MCAO) technique. The presence of cerebral ischemia was verified in ex vivo studies using triphenyltetrazolium chloride (TTC) staining. In vivo radionuclide imaging of cerebral blood flow was performed in rats following MCAO using dynamic planar imaging of 99mTc-exametazime with parallel hole collimation. This was followed immediately by in vivo radionuclide imaging of cerebral blood flow with 99mTc-exametazime in the same animals using 1-mm pinhole SPECT. Correlated computed tomography imaging was performed to localize radiopharmaceutical uptake. The animals were allowed to recover and ex vivo autoradiography was performed with separate administration of 99mTc-exametazime. Time activity curve of 99mTc-exametazime showed that the radiopharmaceutical uptake could be maintained for over 9 min. The activity would be expected to be relatively stable for a much longer period, although the data were only obtained for 9 min. TTC staining revealed sizable infarcts by visual observation of inexistence of TTC stain in infracted tissues of MCAO rat brains. In vivo SPECT imaging showed cerebral blood flow deficit in the MCAO model, and the in vivo imaging result was confirmed with ex vivo autoradiography. We have demonstrated a capability of imaging regions of cerebral blood flow deficit in MCAO rat brains in vivo using a pinhole SPECT dedicated to small animal imaging.

[Research on detection of Vibrio comma and Vibro parahaemolyticus from foodstuffs using MPCR methods].

OBJECTIVE: To establish a set of multi-PCR (MPCR) methods to detect Vibrio comma O1 serogroup (EVC) and O139 serogroup, and Vibrio parahaemolyticus rapidly and sensitively from foodstuffs. METHODS: Using T139 (specific gene of O139 serogroup), ctxB and tcpA genes from V. comma, and tdh gene from V. parahaemolyticus as target sequences, we detected the anticipative amplified bands, whose sizes were relatively 417bp, 564bp, 471bp and 202bp. RESULTS: Excellent specificity of the amplified products could be found from both standard and wild strains of EVC, O139VC and V. parahaemolyticus. It also means that no amplified band was detected from total 35 strains of other bacilli, including salmonella, comma bacillus which do not belong to O1 and O139 serogroups. The detection limits of artificial contaminated samples such as tilapia flesh, oyster and mixture of tilapia intestines and gills were proved to be 22cfu/g in EVC, 50cfu/g in O139 and 65cfu/g in V. parahaemolyticus. Besides, it took only 8-10 hours to finish the whole process. CONCLUSION: Experiment results show that MPCR is a sensitive, convenient and time saving method suitable for detection.

Pinhole single-photon emission computed tomography for myocardial perfusion imaging of mice.

OBJECTIVES: Although transgenic mice have emerged as powerful experimental models of cardiovascular disease, methods for in vivo phenotypic assessment and characterization remain limited, motivating the development of new instruments for biologic measurement. BACKGROUND: We have developed a single-photon emission computed tomography system with a pinhole collimator (pinhole SPECT) for high-resolution cardiovascular imaging of mice. In this study, we describe a protocol for myocardial perfusion imaging of mice using technetium-99m ((99m)Tc)-sestamibi and demonstrate the feasibility for measurement of perfusion defect size from pinhole SPECT images. METHODS: Mice were anesthetized and injected with 370 MBq (10 mCi) of (99m)Tc-sestamibi. Tomographic projection images were acquired by rotating each mouse in a vertical axis in front of a stationary clinical scintillation camera equipped with a pinhole collimator. BALB/c mice (n = 15) were imaged after the permanent ligation of the left anterior descending coronary artery. The resulting defect size was measured from circumferential profiles of short-axis images. After imaging, the hearts were excised and sectioned to obtain ultra-high resolution digital autoradiographs of (99m)Tc-sestamibi, from which the actual infarct size was determined. RESULTS: Reconstructed image quality was equivalent to that obtained for clinical myocardial perfusion imaging. Linear regression analysis produced a correlation coefficient of 0.83 (p < 0.001) between the measured and actual values of the defect size. CONCLUSIONS: These results demonstrate that myocardial perfusion can be characterized qualitatively and quantitatively in mice using pinhole SPECT.

Safety and efficacy of endovascular cooling and rewarming for induction and reversal of hypothermia in human-sized pigs.

BACKGROUND AND PURPOSE: Numerous studies indicate that mild hypothermia provides substantial neuroprotection. However, current systems transfer insufficient heat to rapidly vary core temperature. We thus evaluated the safety and efficacy of endovascular cooling and rewarming for the induction and reversal of hypothermia. METHODS: In 10 anesthetized pigs (weight, 66+/-2 kg), a heat-exchange balloon catheter was inserted into the inferior vena cava and used to cool to a core temperature of 32 degrees C and then rewarm to normothermia. Control animals had 38 degrees C saline infused. Venous blood was sampled before, during, and after cooling. Three animals in each group were killed 1 week later, and the lungs and inferior vena cava were removed for gross and microscopic examination. In 5 additional animals, cardiac output was measured during cooling to 32 degrees C. RESULTS: Body temperature in the hypothermic animals decreased at a rate of 4.5+/-0.4 degrees C/h. Animals were subsequently rewarmed to 36.0+/-0.04 degrees C at 2.5+/-0.2 degrees C/h. There was no difference in heart rate between hypothermic and control animals, whereas systolic pressure decreased during cooling. Cardiac output was well maintained during cooling. There were no thermal effects on blood elements or blood vessels. CONCLUSIONS: The endovascular heat-exchange system effectively cooled and rewarmed pigs with large thermal mass without producing any adverse effects on blood elements, blood vessel integrity, or cardiovascular function.

Effect of endovascular cooling on myocardial temperature, infarct size, and cardiac output in human-sized pigs.

Mild hypothermia reduces myocardial infarct size in small animals; however, the extent of myocardial protection in large animals with greater thermal mass remains unknown. We evaluated the effects of mild endovascular cooling on myocardial temperature, infarct size, and cardiac output in 60- to 80-kg isoflurane-anesthetized pigs. We occluded the left anterior descending coronary artery for 60 min, followed by reperfusion for 3 h. An endovascular heat-exchange catheter was used to either lower core body temperature to 34 degrees C (n = 11) or maintain temperature at 38 degrees C (n = 11). Additional studies assessed myocardial viability and microvascular perfusion with (99m)Tc-sestamibi autoradiography. Endovascular cooling reduced infarct size compared with normothermia (9 +/- 6% vs. 45 +/- 8% of the area at risk; P < 0.001), whereas the area at risk was comparable (19 +/- 3% vs. 20 +/- 7%; P = 0.65). Salvaged myocardium showed normal sestamibi uptake, confirming intact microvascular flow and myocyte viability. Cardiac output was maintained in hypothermic hearts because of an increase in stroke volume, despite a decrease in heart rate. Mild endovascular cooling to 34 degrees C lowers myocardial temperature sufficiently in human-sized hearts to cause a substantial cardioprotective effect, preserve microvascular flow, and maintain cardiac output.