Inhaltsstoffe von Fagaceae (Cupuliferae), 19. Mitt.: Triterpensaponine und Acylflavonoide aus Quercus robur var. stenocarpa Beck.

Constituents of Fagaceae (Cupuliferae), XIX: Triterpene Saponins and Acylated Flavonoids from Quercus robur L. var. stenocarpa Beck. In addition to four known glycosides from leaves of Quercus robur L. var. stenocarpa Beck. a new triterpene saponin has been isolted and identified as 28-β-d-glucopyranosyl ester of the 2α,3β,19α-trihydroxy-olean-12-ene-24,28-dioic acid ( I ).     

Inducible nitric oxide synthase expression in human colorectal cancer: correlation with tumor angiogenesis

To investigate the potential involvement of the nitric oxide (NO) pathway in colorectal carcinogenesis, we correlated the expression and the activity of inducible nitric oxide synthase (iNOS) with the degree of tumor angiogenesis in human colorectal cancer. Tumor samples and adjacent normal mucosa were obtained from 46 surgical specimens. Immunohistochemical expression of iNOS, vascular endothelial growth factor (VEGF), and CD31 was analyzed on paraffin-embedded tissue sections. iNOS activity and cyclic GMP levels were assessed by specific biochemical assays. iNOS protein expression was determined by Western blot analysis. iNOS and VEGF mRNA levels were evaluated using Northern blot analysis. Both iNOS and VEGF expressions correlated significantly with intratumor microvessel density (r(s) = 0.31, P = 0.02 and r(s) = 0.67, P < 0.0001, respectively). A significant correlation was also found between iNOS and VEGF expression (P = 0.001). iNOS activity and cyclic GMP production were significantly higher in the cancer specimens than in the normal mucosa (P < 0.0001 and P < 0.0001, respectively), as well as in metastatic tumors than in nonmetastatic ones (P = 0.002 and P = 0.04, respectively). Western and Northern blot analyses confirmed the up-regulation of the iNOS protein and gene in the tumor specimens as compared with normal mucosa. NO seems to play a role in colorectal cancer growth by promoting tumor angiogenesis.     

Antibiotic Use in Crohn’s Disease

On the assumption that bacteria in the gut may be a cause of symptoms and/or complications of Crohn's disease, various antibiotics are efficaciously employed in some affected patients. However, we do not know exactly why and how they are helpful. A possible explanation is that one or several bacterial species may have a primary role in the aetiology of Crohn's disease, but this is not supported by the data in our possession. Another hypothesis is that intestinal bacteria may cause flare-up of the disorder, either by inducing intestinal lesions or by an interaction with the immune system, but we know today that specific pathogens can cause flares only in a minority of cases. On the contrary, there is considerable evidence that the intestinal microflora and its products may amplify and perpetuate inflammation in Crohn's disease. Despite the fact that few controlled trials have been conducted, and have shown inconclusive results, antibiotics are widely employed for improving symptoms and for inducing remission of active phases. At present, a combination of metronidazole and ciprofloxacin, active against many enteric bacteria, has proved to be effective in the treatment of Crohn's disease complications. This therapy also seems to be effective in acute flares as an alternative to, or in combination with, corticosteroids.     

Genetic instability in superficial bladder cancer and adjacent mucosa: an interphase cytogenetic study

A systematic analysis of both tumors and the surrounding urothelium to help identify what lies behind the mechanism of multifocal tumor development has not yet been performed. In this study we investigated chromosome 1, 7, 9, and 17 aneusomy in 25 superficial papillary carcinomas and in 51 tissue samples taken from sites of macroscopically uninvolved urothelium surrounding the tumors, using the fluorescence in situ hybridization method. Our data demonstrated a close genetic relationship between all examined tumors and normal-appearing mucosa. Numeric aberrations of chromosomes 1, 7, 9, and 17 were found to exhibit similar patterns in all analyzed specimens, although with different frequencies.     

Lightly crosslinked liquid crystalline epoxy resins: The effect of rigid-rod length and applied stress on the state of order of the cured thermoset

Lightly crosslinked liquid crystalline epoxy resins were synthesized by reacting rigid rod epoxy-terminated molecules with decanedioic acid (SA). The obtained networks exhibited a smectic phase even in the case of 2,6-bis(2,3-epoxypropoxy)naphthalene, whose aspect ratio is very low. Upon application of uniaxial stress, a smectic phase was surprisingly obtained also for the system obtained by reacting p-bis(2,3-epoxypropoxy)-benzene (QH), whose aspect ratio is practically equal to one, and SA. Stretching of the smectic samples above the glass transition temperature determines orientation of polymer chains, yielding considerably high values of the order parameter S. Thermomechanical analysis showed, for one of these systems, that stretching induces a shift of the isotropization temperature to higher values.     

The secret life of the mitral valve

In secondary mitral regurgitation, the concept that the mitral valve (MV) is an innocent bystander, has been challenged by many studies in the last decades. The MV is a living structure with intrinsic plasticity that reacts to changes in stretch or in mechanical stress activating biohumoral mechanisms that have, as purpose, the adaptation of the valve to the new environment. If the adaptation is balanced, the leaflets increase both surface and length and the chordae tendineae lengthen: the result is a valve with different characteristics, but able to avoid or to limit the regurgitation. However, if the adaptation is unbalanced, the leaflets and the chords do not change their size, but become stiffer and rigid, with moderate or severe regurgitation. These changes are mediated mainly by a cytokine, the transforming growth factor‐β (TGF‐β), which is able to promote the changes that the MV needs to adapt to a new hemodynamic environment. In general, mild TGF‐β activation facilitates leaflet growth, excessive TGF‐β activation, as after myocardial infarction, results in profibrotic changes in the leaflets, with increased thickness and stiffness. The MV is then a plastic organism, that reacts to the external stimuli, trying to maintain its physiologic integrity. This review has the goal to unveil the secret life of the MV, to understand which stimuli can trigger its plasticity, and to explain why the equation “large heart = moderate/severe mitral regurgitation” and “small heart = no/mild mitral regurgitation” does not work into the clinical practice.     

The role of spontaneous portosystemic shunts in the course of orthotopic liver transplantation

Spontaneous portosystemic shunts are commonly found in cirrhotic patients. Not yet established is their role after orthotopic liver transplantation (OLTx), especially when an increase in portal pressure develops, as during early acute rejection. In this study, 34 cirrhotic patients in a series of 70 OLTx are considered. Each patient had preoperative angiographic assessment, and, in 21 (62%), large spontaneous portosystemic shunts were evident. In 12 cases the shunts were not affected by the surgical procedure and were present during the postoperative period; in 9 the hepatectomy itself involved interruption of the shunts. The patient population was divided into two groups: patients with postoperative shunts (n=12) and those without (n=22). The two groups were similar in age, sex, Child's stage, transplantation variables, and number and grade of rejection episodes. However, mean transaminases (AST) values in the first 2 weeks were significantly higher levels in shunt versus nonshunt patients (421±335 vs 183±126; P<0.025), and this was even more evident when rejection occurred (626±375 vs 195±129; P<0.001). Furthermore, during an acute rejection reaction, three cases showed a true steal phenomenon through the large reopened shunts with ischemic damage to the grafts. The data indicate a possible detrimental effect of the spontaneous shunts on graft perfusion and suggest the prophylactic surgical interruption of the residual shunts during the transplantation.     

Distant muscular (gluteus maximus muscle) metastasis from laryngeal squamous cell carcinoma

Clinical evidence of non-lymphatic distant metastasis has been reported in approximately 10% of cases of head and neck squamous cell carcinoma (HNSCC). The lungs are the commonest site of distant metastasis of HNSCC, followed by the bones, liver and skin. A 65-year-old male underwent supraglottic laryngectomy and left modified neck dissection for a carcinoma of the laryngeal surface of the epiglottis extending to both false cords. Eight months later the patient underwent right radical modified neck dissection for hypodermal metastatic disease involving the underlying (sternocleidomastoid) muscle. Thirty-two months later, surgical excision of a lesion in the right gluteus maximus muscle was performed. Histological study diagnosed a muscular metastasis with the same morphological aspect as the laryngeal carcinoma. The patient showed no evidence of cervical or distant recurrence at follow-up after 13 months. Although skeletal muscles represent approximately 50% of total body mass and receive a large proportion of total cardiac output, haematogenous metastases to skeletal muscle are extremely uncommon. Most skeletal muscle metastases are of pulmonary origin. Distant skeletal muscle metastasis from HNSCC is an extremely rare occurrence. Treatment options, depending upon the clinical setting, include observation, radiotherapy, chemotherapy and excision; these approaches rarely alter the patient outcome. The prognosis associated with skeletal muscle metastasis is thought to be poor, consistent with the fact that it generally occurs as a feature of systemic spread.     

Value of 18-Fluorodeoxyglucose Positron Emission Tomography in the Management of Patients With Cystic Tumors of the Pancreas

OBJECTIVE: To assess the reliability of 18-fluorodeoxyglucose positron emission tomography (18-FDG PET) in distinguishing benign from malignant cystic lesions of the pancreas. SUMMARY BACKGROUND DATA: The preoperative differential diagnosis of cystic lesions of the pancreas remains difficult: the most important point is to identify malignant or premalignant cysts that require resection. 18-FDG PET is a new imaging procedure based on the increased glucose metabolism by tumor cells and has been proposed for the diagnosis and staging of pancreatic cancer. METHODS: During a 4-year period, 56 patients with a suspected cystic tumor of the pancreas underwent 18-FDG PET in addition to computed tomography scanning, serum CA 19-9 assay, and in some instances magnetic resonance imaging or endoscopic retrograde cholangiopancreatography. The 18-FDG PET was analyzed visually and semiquantitatively using the standard uptake value. The accuracy of 18-FDG PET and computed tomography was determined for preoperative diagnosis of a malignant cyst. RESULTS: Seventeen patients had malignant tumors. Sixteen patients (94%) showed 18-FDG uptake with a standard uptake value of 2.6 to 12.0. Twelve patients (70%) were correctly identified as having malignancy by computed tomography, CA 19-9 assay, or both. Thirty-nine patients had benign tumors: only one mucinous cystadenoma showed increased 18-FDG uptake (standard uptake value 2.6). Five patients with benign cysts showed computed tomography findings of malignancy. Sensitivity, specificity, and positive and negative predictive values for 18-FDG PET and computed tomography scanning in detecting malignant tumors were 94%, 97%, 94%, and 97% and 65%, 87%, 69%, and 85%, respectively. CONCLUSIONS: 18-FDG PET is more accurate than computed tomography in identifying malignant pancreatic cystic lesions and should be used, in combination with computed tomography and tumor markers assay, in the preoperative evaluation of patients with pancreatic cystic lesions. A positive result on 18-FDG PET strongly suggests malignancy and, therefore, a need for resection; a negative result shows a benign tumor that may be treated with limited resection or, in selected high-risk patients, with biopsy, follow-up, or both.