Routine Use of Bilateral Skeletonized Internal Thoracic Artery Grafting

Background— Skeletonized harvesting of the internal thoracic artery (ITA) decreases the severity of sternal devascularization, thus reducing the risk of postoperative sternal complications in patients undergoing bilateral ITA grafting.

Methods and Results— Between 1996 and 2001, 1515 consecutive patients underwent skeletonized bilateral ITA grafting. Of the 1179 male and 336 female patients, 641 (42.3%) were >70 years of age, and 519 (34.2%) had diabetes mellitus. Operative mortality was 2.8%. Early postoperative morbidity included sternal infection (1.6%), cerebrovascular accident (3%), and perioperative myocardial infarction (1%). Multiple regression analysis showed chronic obstructive pulmonary disease (odds ratio, 11.3; 95% confidence interval [CI], 4.45 to 28.55), repeat operation (odds ratio, 12.7; 95% CI, 3.25 to 49.56), and diabetes mellitus (non–insulin dependent: odds ratio, 4.64; 95% CI, 1.85 to 11.59; insulin dependent: odds ratio, 6.9; 95% CI, 1.35 to 35.27) to be associated with increased risk of sternal infection. Follow-up (between 5 and 12 years) revealed 305 late deaths. Kaplan-Meier 10-year survival rates for patients <65, 65 to 74, and >75 years of age were 87%, 75%, and 52%, respectively. Cox regression analysis revealed increased overall mortality (early and late) in patients with peripheral vascular disease (hazard ratio [HR], 1.8; 95% CI, 1.39 to 2.33), patients >75 years of age (HR, 7.23; 95% CI, 4.16 to 12.55), those undergoing repeat operations (HR, 2.22; 95% CI, 1.27 to 3.89), patients with preoperative congestive heart failure (HR, 1.64; 95% CI, 1.29 to 3.75), and those with chronic renal failure (HR, 1.52; 95% CI, 1.11 to 2.01). Operations performed without cardiopulmonary bypass were associated with better postoperative survival (HR, 0.66; 95% CI, 0.49 to 0.87).

Conclusions— Bilateral ITA grafting is associated with low morbidity and good long-term results. Use of skeletonized bilateral ITA is appropriate for the elderly and most patients with diabetes; however, it is not recommended for repeat operations or for patients with chronic obstructive pulmonary disease.

A new invasion score for determining the resectability of pancreatic carcinomas with contrast-enhanced multidetector computed tomography

OBJECTIVE

It was the aim of this study to evaluate a new infiltration score to determine the resectability of pancreatic carcinomas in preoperative planning.

MATERIALS AND METHODS

Eighty patients with suspected pancreatic tumor were examined prospectively using 16-row spiral CT. The scans were evaluated for the presence of pancreatic carcinoma, peripancreatic tumor extension and vascular invasion using a standardized questionnaire. Invasion of the surgically relevant vessels was evaluated using a new invasion score. The operative and histological findings and the clinical follow-up served as the gold standard.

RESULTS

Forty patients had a pancreatic carcinoma, 5 had metastasis of a different primary tumor, and in 35 patients, there was no malignant pancreatic disease. The sensitivity for tumor detection was 100%, with a specificity of 88% for differentiating between malignant and benign pancreatic tumors. Invasion of the surrounding vessels was evaluated correctly using the invasion score, with a sensitivity of 89% and a specificity of 99%. In evaluation of resectability, a sensitivity of 94% and a specificity of 89% were achieved.

CONCLUSION

Using 16-row spiral CT, the invasion score is a valid tool for correctly assessing invasion in relevant vessels in cases of pancreatic carcinoma and for determining resectability.

A comparison of angiographic CT and multisection CT in lumbar myelographic imaging

BACKGROUND AND PURPOSE

The purpose of this work was to provide an intraindividual comparison of angiographic CT (ACT) and multisection CT (MSCT) in lumbar myelographic imaging and to evaluate possible benefits of ACT, which is a further development of rotational angiography providing image data of high spatial and CT-like contrast resolution.

MATERIALS AND METHODS

In 26 patients with degenerative lumbar spine disease a lumbar ACT was performed in combination with conventional lumbar myelography and followed by postmyelographic MSCT. Conventional lumbar myelography and lumbar ACT were performed with a flat panel detector-equipped angiographic device. Postmyelographic MSCT was performed with a 16-section CT scanner. Three experienced neuroradiologists rated anonymized sets of multiplanar reformatted CT and ACT images regarding diagnostic and technical parameters. The ratings were repeated after 2 months. Weighted kappa statistics were calculated to describe the levels of intraobserver and interobserver agreement.

RESULTS

The analysis shows that MSCT achieves higher ratings than ACT in all of the parameters asked. An adequate diagnostic quality was only assigned to 80% of the ACT acquisitions compared with 97% of the MSCT acquisitions. All of the mean kappa values were above 0.60, demonstrating a substantial intraobserver and interobserver agreement for MSCT, as well as for ACT.

CONCLUSION

Using ACT, radiographic myelography and myelographic CT can be performed at the same imaging system. However, the results of our study show that the current myelographic ACT image quality fails to apply diagnostic standards. We, therefore, cannot recommend ACT as a general alternative to postmyelographic MSCT.

MnSOD protects colorectal cancer cells from TRAIL-induced apoptosis by inhibition of Smac/DIABLO release

The mitochondrial enzyme manganese superoxide dismutase (MnSOD) has been shown to have two faces with regard to its role in tumor development. On the one side, it is well documented that overexpression of MnSOD slows down cancer cell growth, whereas on the other side MnSOD also has a metastasis-promoting activity. We set out to examine the role of MnSOD in tumor necrosis factor-related apoptosis-inducing ligand (TRAIL)-induced apoptosis, thought to be a first-line tumor surveillance mechanism and failure to undergo apoptosis might contribute to metastasis formation. We show that overexpression of MnSOD at moderate levels is able to protect cells from TRAIL-induced apoptosis. While caspase-8 activation and Bid cleavage were not affected by MnSOD, we detected a marked decrease in caspase-3 activation pointing to a mitochondrial resistance mechanism. Indeed, we found that MnSOD-overexpressing cells showed reduced cytochrome c and no Smac/DIABLO release into the cytosol. The resulting lack of X-linked inhibitor of apoptosis (XIAP) inhibition by cytosolic Smac/DIABLO most likely caused the TRAIL resistance as RNAi against XIAP-rescued caspase-3 activity and TRAIL sensitivity. Our results show that reactive oxygen species are involved in TRAIL-induced Smac/DIABLO release and in TRAIL-triggered apoptosis. Hence, high levels of MnSOD, which decompose and neutralize these reactive oxygen species, might contribute to metastasis formation by allowing disseminated tumor cells to escape from TRAIL-mediated tumor surveillance. As part of TRAIL regimens, adjuvant treatment with XIAP inhibitors in the form of Smac/DIABLO mimetics or MnSOD inhibitors might be able to break TRAIL resistance of malignant tumor cells.

[Gene therapy strategies for colorectal cancer]

Current advances in CRC treatment have led to significant but slight improvements in patient survival with curative outcomes only seen in earlier stage cancers. Consequently, much effort is being put into developing completely novel therapies that fulfil a number of criteria including greater efficacy and fewer side effects. Many of these conditions are met by the wide range of gene therapy strategies currently in pre-clinical or clinical trial phases. Gene therapy approaches may be broadly broken down into three main areas: Following a few tragic events in the context of clinical gene therapy studies, safety is currently the prime concern. Further progress in the field is expected from the combination of the described approaches with conventional treatment modalities.

Improvement of cognitive functions in chronic schizophrenic patients by recombinant human erythropoietin

Schizophrenia is increasingly recognized as a neurodevelopmental disease with an additional degenerative component, comprising cognitive decline and loss of cortical gray matter. We hypothesized that a neuroprotective/neurotrophic add-on strategy, recombinant human erythropoietin (rhEPO) in addition to stable antipsychotic medication, may be able to improve cognitive function even in chronic schizophrenic patients. Therefore, we designed a double-blind, placebo-controlled, randomized, multicenter, proof-of-principle (phase II) study. This study had a total duration of 2 years and an individual duration of 12 weeks with an additional safety visit at 16 weeks. Chronic schizophrenic men (N=39) with defined cognitive deficit (>or=1 s.d. below normal in the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS)), stable medication and disease state, were treated for 3 months with a weekly short (15 min) intravenous infusion of 40,000 IU rhEPO (N=20) or placebo (N=19). Main outcome measure was schizophrenia-relevant cognitive function at week 12. The neuropsychological test set (RBANS subtests delayed memory, language-semantic fluency, attention and Wisconsin Card Sorting Test (WCST-64) - perseverative errors) was applied over 2 days at baseline, 2 weeks, 4 weeks and 12 weeks of study participation. Both placebo and rhEPO patients improved in all evaluated categories. Patients receiving rhEPO showed a significant improvement over placebo patients in schizophrenia-related cognitive performance (RBANS subtests, WCST-64), but no effects on psychopathology or social functioning. Also, a significant decline in serum levels of S100B, a glial damage marker, occurred upon rhEPO. The fact that rhEPO is the first compound to exert a selective and lasting beneficial effect on cognition should encourage new treatment strategies for schizophrenia.

Effects of Mycophenolic Acid on Inosine Monophosphate Dehydrogenase I and II mRNA Expression in White Blood Cells and Various Tissues in Sheep

Mycophenolic acid (MPA) is a mycotoxin commonly found as Penicillium genus secondary metabolite in feedstuffs and silages. Feeding with MPA contaminated silages may modulate the immune system in the farm animals and can cause appetite lost, ketosis, paralysis and abortion. The aim of the present study was to characterize the long-term MPA effect on both the inosine monophosphate dehydrogenase (IMPDH) isoforms I and II mRNA expression in white blood cells (WBC) and various tissue of healthy sheep. In treated animals 300 mg MPA/day/sheep was applied. In all investigated tissues the IMPDH I and II mRNA was abundant: WBC, spleen, thymus, ileum, jejunum, kidney, liver, pharyngeal and mesenterial lymph node. An efficiency-corrected relative quantification of the IMPDH types I and II isoforms mRNA were performed by normalizing with the constant reference gene expression of beta-actin. High IMPDH I mRNA expression levels were seen in kidney > mesenterial lymph node > jejunum > spleen > pharyngeal lymph node. Medium and low abundance was found in ileum > WBC > liver > thymus. Type II mRNA was highly expressed in liver > thymus > jejunum. In pharyngeal lymph node > spleen > ileum > mesenterial lymph node > kidney > WBC medium to low IMPDH II mRNA concentrations were detected. Under MPA treatment the IMPDH I mRNA expression was not significantly regulated in WBC, only trends of down- and upregulation were observed. Surprisingly in jejunum an upregulation could be observed (P < 0.05). In pharyngeal lymph node a tendency to downregulation was shown. This may be due to frequent ruminant activities and frequent exposition of MPA to the pharyngeal lymph nodes. In contrast to type I mRNA expression, IMPDH II mRNA was significantly downregulated in ileum (3.4-fold, P < 0.01) and tendencies in downregulation could be seen in jejunum (5.1-fold, P = 0.14). In addition, significant downregulation of IMPDH II gene expression over the entire feeding experiment could be shown in WBC of MPA-treated animals compared with untreated animals (P < 0.05). In conclusion, the recent study demonstrates that feeding sheep with MPA-contaminated silage did not induce IMPDH I mRNA expression in various tissues and blood, except in jejunum, but has suppressive effects on IMPDH II mRNA expression in WBC and ileum.

Core hypothermia in multiple sclerosis: case report with magnetic resonance imaging localization of a thalamic lesion

Hypothermia is a rare condition in multiple sclerosis (MS). We report on a patient with a long-standing secondary progressive MS and six episodes of recurring hypothermia down to 29.9 degrees C with associated hypotension, bradycardia, coagulopathy and electrolyte dysequilibrium. Magnetic resonance imaging (MRI) demonstrated severe involvement of the corpus callosum with an associated lesion in the right posterior thalamus. These findings may link hypothermia in MS with callosal and associated thalamic pathology to Shapiro's syndrome, where agenesis of the corpus callosum and associated abnormalities are related to episodic spontaneous hypothermia. In MS, hypothermic episodes may be triggered by preceding infections, as shown in the present case.

Morphological Findings in Lymphatic Tissues of Sheep Following Oral Application of the Immunosuppressive Mycotoxin Mycophenolic Acid

Mycophenolic acid (MPA) is applied in immunosuppressive therapy after organ transplantation. As a common contaminant in silage, this substance is also frequently fed to sheep unintentionally. In this study, the effect of MPA on the immune system of sheep was examined. Four groups of 9 sheep each were fed 0, 0.5, 1.2, or 5 mg of MPA per kg body weight per day for 6 weeks. Then, the animals were slaughtered and various organs were examined macroscopically, histologically, and immunohistochemically. No effect of MPA on general health was detected. With increasing dose of MPA, germinal centres in the retropharyngeal lymph nodes displayed an activated morphology with numerous centroblasts. In the highest dose group, the sheep showed shrinkage of thymic lobules. The numbers of IgG or IgM positive plasma cells decreased in the ileum with increasing MPA-doses. These results suggest, that MPA in a high concentration may affect the morphology of immune organs of sheep.