Role of chromogranin A-derived fragments after resection of nonfunctioning pancreatic neuroendocrine tumors

PURPOSE

No single reliable biomarker is available for nonfunctioning pancreatic neuroendocrine tumors (NF-PanNETs). Vasostatin-1 (VS-1), the N-terminal fragment of chromogranin A (CgA), seems to be a more accurate biomarker compared to its precursor. Primary aim was to investigate the ability of VS-1, compared to total-CgA, to assess the effectiveness of surgical resection performed for NF-PanNETs. Secondary aim was to evaluate two additional CgA-derived fragments, pancreastatin (PST) and vasostatin-2 (VS-2), as possible biomarkers for NF-PanNETs.

METHODS

Consecutive patients who underwent surgery for NF-PanNETs at San Raffaele Scientific Institute were included (n = 35). Plasma levels of CgA and CgA-derived fragments were measured by Enzyme-Linked ImmunoSorbent Assay (ELISA), preoperatively and postoperatively.

RESULTS

Preoperative VS-1 was significantly higher compared to VS-1 measured on postoperative day 5 (POD5) (pre: 0.338 nM versus POD5: 0.147 nM, P < 0.001), whereas total-CgA significantly increased after surgery (pre: 1.123 nM versus POD5: 1.949 nM, P = 0.006). Overall, 24 patients showed ≥ 1 feature of tumor aggressiveness (T3-T4, nodal/distant metastases, Ki67 > 5%, microvascular/perineural invasion, necrosis). The median percentage decrease in VS-1 plasma levels was 63% (IQR 28-88%) among patients with aggressive tumors, compared to 13% (IQR 0-57%) in the remaining population (P = 0.033). No significant differences in terms of PST (P = 0.870) and VS-2 (P = 0.909) were observed between preoperative and postoperative time.

CONCLUSION

VS-1 provides an early assessment of surgical efficacy in patients who undergo resection for NF-PanNETs, especially in those with aggressive neoplasms. Total-CgA, PST and VS-2 have no clinical utility in this setting.

Biodegradable Polymer (D,L-Lactide-ε-Caprolactone) in Aortic Vascular Prosthesis: Morphological Evaluation in an Animal Model

Biodegradable D,L-Lactide-ε-caprolactone copolymer was used in substitution to bovine collagen to seal porosity in nine Dacron vascular Sorin Carbografts®. One served as control and 8 were implanted in mini-pigs as vascular by-pass in the thoracic aorta. The grafts were explanted at 7 days (4 animals), 30 (2 animals) and at 90 days (2 animals), and submitted to gross examination, X-ray, histology and electron microscopy.

Aim of the study was to assess the safety and the reliability of these polyester vascular prostheses impregnated with the copolymer in terms of containment of the bleeding in the perioperative period, host inflammatory response, copolymer biodegradation and prostheses “healing”.

All the grafts were patent at angiographic and X-ray examination. At 7 days blood infiltration between Dacron and copolymer lining was detected. Inflammatory granulocyte infiltrates and granulomatous reaction with polymer degradation was observed at 30 days and fibrous tissue healing at 90 days. Luminal surface was covered by thin thrombi at 7 and by a neointima at 30 and 90 days.

We conclude that D,L-Lactide-ε-caprolactone copolymer is effective in preventing perigraft bleeding, even though an early hematoma between Dacron and the copolymer coating occurs. Copolymer is degraded through a mild inflammatory reaction, with eventual evolution to fibrous healing.

[Clinical dialysis: new problems and new prospects]

The main problem nephrologists have to face today is the very high patient morbidity and mortality. A number of traditional and non-traditional risk factors have a role; among these anaemia, hypertension, dislipidemia, abnormalities in calcium-phosphate metabolism, hyperhomocysteinemia and endothelial dysfunction. An important innovation in the field of hemodialysis has been the availability of high-permeable and high-flux membranes, characterized by a high biocompatibility and ultrafiltration coefficient. The development of automatic systems to control ultrafiltration has enabled the utilisation of these membranes in the clinical setting (high-flux hemodialysis, hemofiltration, hemodiafiltration). It is common opinion that high-flux membranes can positively influence cardiovascular instability, but this has not been confirmed by clinical trials. Although preliminary data indicated a favorable effect on the correction of anemia in patients treated with high-permeable membranes, randomized trials have not shown a significant effect. Better control of anemia could be possible by means of on-line treatments, given their higher removal of medium- and large molecules and reduced microbiological and pyrogenic contamination of the dialysate. A number of analyses showed a lower incidence of bone cysts and/or carpal tunnel syndrome in patients treated with high-flux membranes compared to low-flux ones. High-flux treatments could reduce morbidity and mortality in hemodialysis patients. However, despite its large sample size, the HEMO Study has not been capable of showing a statistically significant effect of higher dialysis dose and high-flux membranes on survival and morbidity. The MPO study has been expressively designed to do a prospective evaluation of the long-term effect of membrane permeability on clinical outcomes. These results are greatly awaited.

Is the Olympic boardsailor an endurance athlete?

The present study was carried out in order to describe the physiological profile of top Olympic boa rdsailors of both genders and to measure the energy cost during actual boardsailing with particular attention to the most demanding conditions. Fourteen elite Olympic boardsailors (7 males and 7 females) volunteered to participate in the study. Each subject underwent a maximal cycle ergometer test in orderto measure VO2peak and ventilatory threshold (Tvent). Additionally, anthropometric measurements including body fat percentage were taken. The cardiorespiratory demand and the energy cost of actual boardsailing were assessed by means of a very light telemetric device (K2 Cosmed) which allowed the measurements of VO2, VE and HR. VO2peak was 63.6 +/- 2.3 ml x kg(-1) x min(-1) (Tvent 70% of maximum) and 49.2 +/- 4.1 (Tvent 60% of maximum) in males and females, respectively. The data recorded during actual boardsailing show that this sport activity can be classified as aerobic, the VO2 values being above or very close to those of Tvent values (75% and 60% of the maximum in males and females). Furthermore the mean blood lactate values obtained at the end of each regatta testing were 6 +/- 2 mMol x l(-1) in males and 5 +/- 1.5 mMol x l(-1) in females indicating a partial involvement of anaerobic metabolism, which in some regatta phases could represent a limiting factor for performance.

The efficiency of walking of paraplegic patients using a reciprocating gait orthosis

A number of orthoses have been designed to restore stance and walking in paraplegic subjects. Among them, the reciprocating gait orthosis (RGO) appears to be one which is most widely adopted. The great energetic cost of orthotically aided walking is the main factor limiting the walking capability of paraplegic subjects. The purpose of the present research was to give a complete biomechanical evaluation of RGO locomotion in order to provide data that can be used for further improvements of the orthosis. From the whole body kinematics the mechanical work done to move the orthosis was estimated; by measuring the actual metabolic cost of RGO locomotion the efficiency was evaluated as the ratio between mechanical work and energy expenditure. It is found that RGO locomotion is a very demanding task in terms both of energy expenditure and of the mechanical work required. Furthermore, it is evident that the major determinant of this poor efficiency of RGO locomotion is the enormous amount of work required to move the orthosis which, in turn, reflects its poor mechanical characteristics. To accomplish the demand of real mobility, devices for transferring work from the upper to the lower portion of the body must be substantially improved. This technical aspect must be parelleled by suitable training programmes especially designed to improve the aerobic power of paraplegic subjects and their body composition (ie less fat and more muscle).

Can evoked phonomyography be used to recognize fast and slow muscle in man?

The present study is aimed at ascertaining if muscle sound might be used as a detector of the contractile properties of individual human muscles "in vivo". In order to test this hypothesis, Soleus muscle (slow) and Vastus Lateralis Femoris muscle (fast) were investigated in three healthy subjects during electrically elicited contractions. Evoked phonomyograms were obtained from isometric single twitch contractions using a microphonic apparatus. Time and frequency domain analysis were performed. Evoked phonomyogram rising time values obtained from the two muscles are significantly different (p less than .01) and this difference is clearly due to their different mechanical properties. The power spectrum of all signals was obtained by means of harmonic analysis routine and mean frequency thus obtained was taken into account. Power spectrum values are approximately 1.5 times greater in fast muscle than in slow muscle (p less than .01). These findings lead us to the conclusion that evoked phonomyography can be considered a useful technique for the assessment of mechanical properties of individual human muscles.

HCV in a group of chronic hemodialysis patients

Since HCV appears to be the major cause of post-transfusion non-A, non-B hepatitis in Italy, this study determines the presence of anti-HCV in a risk group. Among 26 patients, 9 were anti-HCV in a risk group. Among 26 patients, 9 were anti-HCV positive with the ELISA test and all of them were confirmed with the RIBA test of 2nd generation. Only 1 had a poussés movement of ALT levels. Hemodialyzed patients are reactive for HCV probably for the transfusional therapy.

Cervical schwannoma with intranuclear vacuoles by fine-needle sampling without aspiration

In a 49-yr-old woman who presented with a cervical mass, a fine-needle specimen without aspiration was suggestive of paraganglioma; there were spindle-shaped cells with pseudoacinar structures and prominent intranuclear vacuoles. Subsequent examination of a mass removed from the vagus nerve clearly identified a schwannoma. The differential diagnosis is discussed, particularly in relation to the presence of intranuclear vacuoles, and it is concluded that this cytological characteristic should not in itself define the diagnosis.