A comparative study of angiogenic and cytokine responses after laparoscopic cholecystectomy performed with standard- and low-pressure pneumoperitoneum

Background  Surgical procedures enhance production of pro- and anti-inflammatory cytokines and angiogenic factors that play a pivotal role in the immunological response to surgical trauma and take part in the pathogenesis of tumor growth and adhesions formation. The purpose of the study was to access the influence of low-pressure CO₂ pneumoperitoneum on the inflammatory and angiogenic responses during the postoperative period after laparoscopy. Methods  The study group consisted of 40 patients, operated on due to cholelithiasis using standard-pressure (n = 20) and low-pressure (n = 20) CO₂ pneumoperitoneum. Serum concentration of interleukin (IL)-6, IL-8, IL-10, vascular endothelial growth factor (VEGF)-A, and endostatin were measured before and at 6, 24, and 48 h after surgery with commercially available enzyme-linked immunosorbent assay (ELISA). Results  Concentrations of IL-6 increased significantly after the operations in both groups. No differences were observed between the groups in regards to IL-6, IL-8, and IL-10 levels. Concentrations of VEGF-A measured at 6 and 48 h were significantly lower in patients who underwent laparoscopies performed with low-pressure pneumoperitoneum. No significant variations were observed in endostatin serum concentration. Concentrations of the studied parameters were not influenced by duration of surgery or by age, gender, or body mass index (BMI) of the patients. Conclusions  The results obtained in our study do not show any significant differences between studied operative procedures with regards to systemic inflammatory response. Changes in the concentrations of VEGF-A and endostatin observed in the studied population may suggest this technique is more favorable with regards to angiogenesis process intensity, along with all its consequences and implications.     

Stereological evaluation of liver volume in living donor liver transplantation using MDCT via the Cavalieri method.

In living donor liver transplantation (LDLT), obtaining the precise volume of the graft is very important to decrease volume-related postoperative complications, especially in cases with suspected small-for size grafts. We used stereology based on the Cavalieri method (CM), a new method to measure liver graft volume, and compared the results with those obtained through intraoperative measurement (IOM) and through multidetector computed tomography (MDCT) measurement. Liver volumes estimated using the 3 methods were well-correlated with each other (r(2) = 0.94 and P < 0.001 for IOM and CM; r(2) = 0.91 and P < 0.001 for IOM and MDCT, and r(2) = 0.95 and P < 0.001 for CM and MDCT); however, they were different from each other (in descending order, 908 +/- 124 cm(2), 861 +/- 121 cm(2), and 777 +/- 168 cm(2) for MDCT, CM, and IOM, respectively). Although MDCT and CM overestimated the volumes, the results of CM were almost similar to those obtained via IOM. In conclusion, our results suggest that CM measured the liver graft volume more reliably. Thus, its use, particularly in cases with suspected small-for-size graft, may prove useful.     

RASER: a new ultrafast magnetic resonance imaging method.

A new MRI method is described to acquire a T(2)-weighted image from a single slice in a single shot. The technique is based on rapid acquisition by sequential excitation and refocusing (RASER). RASER avoids relaxation-related blurring because the magnetization is sequentially refocused in a manner that effectively creates a series of spin echoes with a constant echo time. RASER uses the quadratic phase produced by a frequency-swept chirp pulse to time-encode one dimension of the image. In another implementation the pulse can be used to excite multiple slices with phase-encoding and frequency-encoding in the other two dimensions. The RASER imaging sequence is presented along with single-shot and multislice images, and is compared to conventional spin-echo and echo-planar imaging sequences. A theoretical and empirical analysis of the spatial resolution is presented, and factors in choosing the spatial resolution for different applications are discussed. RASER produces high-quality single-shot images that are expected to be advantageous for a wide range of applications.     

Improved intracranial lesion characterization by tissue segmentation based on a 3D feature map

Our aim was to develop an accurate multispectral tissue segmentation method based on 3D feature maps. We utilized proton density (PD), T₂-weighted fast spin-echo (FSE), and T₁-weighted spin-echo images as inputs for segmentation. Phantom constructs, cadaver brains, an animal brain tumor model and both normal human brains and those from patients with either multiple sclerosis (MS) or primary brain tumors were analyzed with this technique. Initially, misregistration, RF inhomogeneity and image noise problems were addressed. Next, a qualified observer identified samples representing the tissues of interest. Finally, k-nearest neighbor algorithm (k-NN) was utilized to create a stack of color-coded segmented images. The inclusion of T₁ based images, as a third input, produced significant improvement in the delineation of tissues. In MS, our 3D technique was found to be far superior to that based on any combination of 2D feature maps (P < 0.001). We identified at least two distinctly different classes of lesions within the same MS plaque, representing different stages of the disease process. Further, we obtained the regional distribution of MS lesion burden and followed its changes over time. Neuropsychological aberrations were the clinical counterpart of the structural changes detected in segmentation. We could also delineate the margins of benign brain tumors. In malignant tumors, up to four abnormal tissues were identified: 1) a solid tumor core, 2) a cystic component, 3) edema in the white matter, and 4) areas of necrosis and hemorrhage. Subsequent neurosurgical exploration confirmed the distribution of tissues as predicted by this analysis.     

Effects of methimazole pretreatment on cerulein induced acute pancreatitis in rats.

BACKGROUND: Many interrelationships exist between the thyroid gland and the gastrointestinal tract. Several past and recent studies have shown that the thyroid gland profoundly influences the structure and function of the exocrine pancreas in the rat. In the present study we investigated the effect of methimazole (METZ), an antithyroid drug, on cerulein induced acute pancreatitis (AP) in rats. METHODS: Rats were divided into 3 groups (10-12 weeks age, 200-250 g weight, n: 10). Group B was made hypothyroid with methimazole 5 mg/kg daily for 10 days and the others were untreated euthyroid groups. After 10 days, acute pancreatitis was induced with four doses of 20 microg/kg body weight of cerulein administered s.c at hourly intervals in group A and B while the control group C was given 4 doses of I ml saline. Pancreas wet weight (mg), plasma amylase activity (IU/l) and pancreatic histology were used as endpoints to quantify the severity of the AP. RESULTS: Plasma tri-iodothyronine (T3) (ng/dl) and thyroxine (T4) (microg/dl) levels were significantly reduced after METZ treatment for 10 days (p < 0.01). METZ pretreatment reduced significantly the cerulein induced increase in pancreatic weight (1,205 +/- 12 mg in METZ treated AP group versus 1,617 +/- 14 mg in AP group, p < 0.05) and the rise in amylase activity (7,078 +/- 816 IU/l in METZ treated AP group versus 8,611 +/- 830 IU/l in AP group p < 0.05). CONCLUSION: METZ reduces the severity of cerulein induced AP in rats. This effect might be through its antithyroid property.     

Multi-phase approach to eradicate enzootic mouse coronavirus infection.

Infections with mouse coronavirus (also known as mouse hepatitis virus, MHV) are common and prompt concern because the adverse research effects of infection have been well documented. The animal facility we describe had contained an enzootic infection of mouse coronavirus for more than a decade. Eradication of the virus had been tried with limited success in the past. With an increase in the populations of immune-compromised and transgenic animals elsewhere in the facility, eradication of the virus became a high priority. The affected animals were in multiple breeding colonies comprising more than 4000 mice representing more than 50 site-specific strains, lines, and sublines. A task force designed to ensure representation of all interested parties developed a multi-phase approach which included (a) culling of nonessential animals, (b) cessation of breeding, (c) testing and culling of individual animals, and (d) cross-fostering to clean dams. To date, all of the strains, lines, and sublines manipulated through this multi-phase eradication approach continue to test negative for mouse coronavirus. This multi-phase approach may be useful for other institutions attempting to eradicate mouse coronavirus.