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Biomedical subjects

S Mattioli

Publications and source records attributed to S Mattioli.

At least 37 records · Page 2Linked to original sources
PubMed1997

Patient position for a synchronous cervicothoracoabdominal two-team esophagectomy.

Cervicothoracoabdominal and cervicoabdominal approach are routinely adopted for total or subtotal esophagectomy. We propose a modification of the Nanson's patient position to optimize sequential or simultaneous left cervicotomy, laparotomy, and eventual right thoracotomy with one or two surgical teams. This technique permits better control of the operative field for each phase of the procedure with coordinated operating of two surgical teams on the neck, abdomen, and chest.

Esophagectomy↗
PubMed1996

Onset timing of delayed complications and criteria of follow-up after operation for esophageal achalasia.

BACKGROUND: The purpose of this study was to define the length of follow-up necessary to obtain definitive results of the Heller myotomy for the therapy of esophageal achalasia and the modalities of long-term follow-up. Insufficient myotomy, periesophageal scarring, and gastroesophageal reflux esophagitis are the most common late complications of operation for achalasia. Columnar-lined esophagus with or without dysplasia and cancer can further complicate postoperative reflux esophagitis. Because progressive worsening of results with time has been reported, we assessed the timing of appearance of these complications. METHODS: Since 1973, 129 patients submitted to Heller myotomy were clinically and objectively followed up. Mean follow-up was 97.4 months (range, 12 to 268 months). Of 129 patients, 42 were followed up for less than 5 years (17 voluntary drop outs, 10 reoperations, 3 deaths, 12 in follow-up), 47 more than 5 years, 26 more than 10 years, 12 more than 15 years, and 2 more than 20 years. The timing of onset of symptoms and complications related to the myotomy were evaluated as was the development of dysplasia and cancer. RESULTS: In 11 patients, severe dysphagia due to insufficient myotomy reappeared a mean of 12.4 months after the operation (range, 3 to 30 months). In 7 patients with periesophageal scarring, dysphagia recurred a mean of 18.8 months (range, 6 to 28 months) after the operation. Postoperative reflux esophagitis appeared in 22 patients a mean of 76.5 months (range 21 to 168 months) after the operation. Columnar-lined esophagus was detected in 8 patients a mean of 143.1 months (range, 85 to 230 months) after the operation. Mild to moderate dysplasia was found in 5 of 8 patients with columnar-lined esophagus a mean of 191.6 months after the operation (range, 152 to 287 months), and intramucosal adenocarcinoma was found in 1 patient with columnar-lined esophagus after 8 years. CONCLUSIONS: Dysphagia secondary to insufficient myotomy and periesophageal scarring recurs early, not later than 3 years. Conversely, abnormal gastroesophageal reflux with related complications can appear more than 10 years postoperatively. Five years after the operation the follow-up should be primarily endoscopic and histologic. Results should withstand a follow-up of at least 10 years.

Actuarial Analysis↗
PubMed1995

Insertion of a short human immunodeficiency virus (HIV)-2 gp36 sequence into an HIV-1 p24 recombinant protein results in a polypeptide with potent and TCRBV-restricted T cell triggering activity.

In the present work we investigate whether artificial alterations of the structure of an inactive retrovirus-encoded protein could transform it in a superantigen. As a model system we used a recombinant human immunodeficiency virus (HIV)-1 p24 protein and two of its variants in which a short peptide corresponding to sequences of gp41 of HIV-1 (HIV-1 p24*) or gp36 of HIV-2 (HIV-1-2 p24*) has been inserted nearby the carboxy-terminal end of HIV-1 p24. As expected both HIV-1 p24 and HIV-1 p24* were inactive, while HIV-1-2 p24* was a potent inducer of human, but not murine, T cell proliferation. The possibility that the observed activity was due to contaminants was ruled out since the proliferative response could be specifically inhibited by a monoclonal anti-p24 antibody and by a peptide encompassing the area of HIV-1 p24/HIV-2 gp36 junction. Furthermore, the data exclude the possibility that the gp36 insertion is per se responsible for the observed proliferative activity. The analysis of the functional, phenotypic and molecular properties of the responding cells demonstrated that the response was class II dependent and that the activated cells were predominantly CD4+CD8- expressing a strongly biased repertoire of TCRBV segments. Collectively, these data strongly suggest that the HIV-1-2 p24* fusion protein shares common functional properties typical of superantigen molecules. Thus, our demonstration that a viral protein can be transformed into a superantigen simply by the insertion of a short peptide at the carboxy-terminal end has important implications for understanding the mode of action of retrovirus-encoded superantigens.

Amino Acid Sequence↗
PubMed1995

Use of bare fiber with siderfiring Albarran bridge in laser therapy of the prostate.

Laser coagulation of the prostate has been performed using a bare fiber passed through a sidefiring Albarran bridge containing a distal gold-plated reflector with a deflecting mechanism. The system and the fiber can be used for several dozen treatments. Transurethral laser coagulation with the new Albarran bridge and the noncontact Nd:YAG laser was performed on 45 patients for obstructive symptoms caused by benign prostatic hyperplasia. The dosimetry was 1000 J per 1 cc of prostatic tissue at 60 W for 60 seconds. Successful results were obtained in 38 patients (85%). A significant reduction in obstructive symptoms from a mean AUA-6 Symptom Score of 21.2 preoperatively to 9.1 at 3 months and 7.6 at 6 months was associated with an increase in the peak urine flow rate from 6.1 mL/sec preoperatively to 13.1 mL/sec at 3 months and 15.7 mL/sec at 6 months. The residual urine volume averaged 190 mL preoperatively and 35 mL at 6 months. Transurethral laser coagulation of the prostate represents a useful alternative to transurethral resection, especially in the high-risk patient with an enlarged median lobe or a small prostate. The treatment is bloodless and, with the aid of the modified Albarran bridge, can be performed with a standard urologic Nd:YAG laser. The new Albarran bridge also can reduce the cost of laser treatment.

Aged↗
PubMed1995

Mimicry of the immunodominant conformation-dependent antigenic site of hepatitis A virus by motifs selected from synthetic peptide libraries.

Hepatitis A virus (HAV) is a positive-strand RNA virus with a genome length of approximately 7,480 nucleotides. Although HAV morphogenesis is thought to be similar to that of poliovirus, the prototype picornavirus, the complete characterization of the antigenic structure of this virus remains elusive. All the available evidences, however, support the existence, on HAV virions and empty capsids, of an immunodominant neutralization antigenic site which is conformation dependent and whose structure involves residues of both VP1 and VP3 capsid proteins. This particular feature and the difficulty of obtaining high virus yield in tissue cultures make HAV an ideal target for developing synthetic peptides that simulate the structure of its main antigenic determinant. To this end we utilized, in the present work, the divide-couple-recombine approach to generate a random library composed of millions of different hexapeptides. This vast library was screened with a well-characterized anti-HAV monoclonal antibody. By this strategy we identified a peptide that reacted specifically with monoclonal and polyclonal anti-HAV antibodies and, in mice, induced a specific anti-virus immune response. Furthermore, the peptide could also be used in an enzyme-linked immunosorbent assay for revealing a primary immunoglobulin M immune response in sera of acutely infected human patients. Interestingly, no sequence homology was found between the identified peptide and the HAV capsid proteins VP1 and VP3. Collectively, these data represent an additional important paradigm of a mimotope capable of mimicking an antigenic determinant with unknown tertiary structure.

Amino Acid Sequence↗
PubMed1994

Superantigen-reactive human T cells express a biased repertoire of T-cell receptor V beta joining regions.

A major characteristic of superantigens is their ability to stimulate T cells based predominantly on the type of variable segment of the T-cell receptor (TCR) V beta chain. Recently, however, reports from several laboratories have also implied a role for non-V beta elements in superantigen binding. The goal of the present study was to determine whether TCR V beta-D beta-J beta joining sequences may influence the interaction of superantigens with their target cells. To ascertain how the actual TCR repertoire of superantigen-triggered cells deviates from the theoretical one, we generated a large panel of joining region sequences from TCR carrying the TCR V beta 12 and TCR V beta 5,1 regions. The 245 sequences analysed represent transcripts of T cells from the same donor triggered either with an anti-CD3 monoclonal antibody or with the Staphylococcus aureus enterotoxins. Comparison of the joining sequences of these different groups demonstrates a skewed J beta usage in the sequences derived from superantigen-triggered cells and also provides evidence that ascribes to the putative CDR3 region of V beta segments a role in superantigen recognition. Finally, the data presented give some hints of the regions of the putative CDR3 loop that may play a major role in this function.

Amino Acid Sequence↗
PubMed1994

Endoscopy versus endoscopic ultrasonography in staging reflux esophagitis.

Precise staging of reflux esophagitis is very important for therapeutic decisions; in fact, chronic gastroesophageal reflux may cause transmural inflammation that leads to fibrosis with loss of esophageal wall compliance. In reflux esophagitis, endoscopic stating is limited to mucosal injury, while endoscopic ultrasonography (EUS) is able to visualize changes in the layer structure and localized or diffuse thickenings of the esophageal wall. In order to evaluate the usefulness of EUS in reflux esophagitis, a prospective study of 31 patients and ten normal subjects was performed. Endoscopic reflux esophagitis was staged as: E1 (erythema, n = 7), E2 (erosions, n = 13), E3 (ulcers, n = 11). EUS findings were recorded and evaluated at five different levels, starting from the gastroesophageal junction, using a quantitative method, the center line method. With this method, the sectorial and mean thickness, and area were calculated for each level. There was a significant difference between patients with reflux esophagitis and normal subjects in our study. E3 patients showed a significant upward involvement of the wall far from the visible lesions. Mild esophagitis may also cause esophageal wall thickening, involving even the entire wall. There was no correlation between the onset time of symptoms and the degree of thickening. In conclusion, EUS seems to be an important supplement to endoscopy in staging reflux esophagitis, as the progression of the inflammation is not related to the endoscopic findings.

Adult↗
PubMed1994

[The laparoscopic treatment of functional esophageal diseases. Preliminary experience with Nissen's intervention and Heller-Dor's intervention].

UNLABELLED: Aim of the study is to analyse the preliminary results that we obtained with laparoscopic surgery for esophageal functional diseases. Twenty four patients between April 1992 and December 1993 underwent laparoscopic procedures for gastroesophageal reflux disease and achalasia, respecting the same principles adopted for the traditional surgery. A 360 degrees Nissen fundoplication modified according to DeMeester was performed in 12 patients with severe cardial incontinence or reducible gastric hiatal hernia. The 12 patients with achalasia underwent esophagogastric myotomy associated with a Dor hemifundoplication. Myotomy and gastroplasty were performed under manometric control. The mortality was zero in both techniques. All Nissen procedures were completed laparoscopically, while 2 Heller-Dor were converted to the laparotomy version. The mean duration time of the procedure has been 190' for the Nissen operation and 230' for the Heller-Dor. In one patient submitted to the antireflux gastroplasty occurred a pleural effusion. The short term results (mean follow-up 6 months) of the laparoscopic procedures were comparable with the traditional laparotomy operation. IN CONCLUSION: the two procedures are feasible via laparoscopy; the intraoperative manometry is useful for the Heller-Dor operation; the laparoscopic approach for functional diseases must be considered experimental until were obtained satisfactory long term results.

Adult↗
PubMed1993

Intraoperative study on the relationship between the lower esophageal sphincter pressure and the muscular components of the gastro-esophageal junction in achalasic patients.

OBJECTIVE: The lower esophageal sphincter (LES) resting tone originates from the tension of the muscular fibers of the gastro-esophageal (GE) junction. This study determined which of the muscular structures' of the GE junction are actually responsible and to what degree for the LES resting tone in achalasic patients. SUMMARY BACKGROUND DATA: Controversy still exists as to the length of myotomy on the esophageal and gastric sides of the GE junction. Experimental and clinical studies have supposed that the anatomical complex formed by the U and the sling fibers of the lesser curvature of the stomach can be part of the LES. METHODS: The variations induced on the LES resting tone by the separate division of the esophageal and gastric muscular fibers of the GE junction were studied by means of intraoperative manometry in 32 patients who underwent myotomy for achalasia. RESULTS: After surgical preparation of the GE junction, the mean pressure was 29.3 +/- 13 mmHg. After esophageal side myotomy, the mean LES pressure decreased to 13.6 +/- 7.9 mmHg (paired t test, p < 0.0005). The residual pressure was further reduced after gastric side myotomy (3.4 +/- 1.9 mmHg; paired t test, p < 0.0005). CONCLUSIONS: In achalasic patients, 45% of the LES resting tone is maintained by the gastric side anatomical component of the GE junction. The range of variability of the gastric component of the LES is wide. This information should be taken into account when performing extramucosal myotomy as therapy for esophageal achalasia.

Esophageal Achalasia↗
PubMed1992

Indications for 24-hour gastric pH monitoring with single and multiple probes in clinical research and practice.

The methodology of prolonged gastric pH monitoring has not yet been standardized with regard to the number and position of pH probes. Twenty-seven healthy volunteers and 11 patients affected by nonulcer dyspepsia have been submitted to 24-hr ambulatory simultaneous pH monitoring of the distal esophagus, fundus, and antrum. Fundic and antral pH profiles have been compared and causes of pH variations (pH > 4) identified. Both in healthy volunteers and dyspeptic patients, percentile curves of fundic and antral pH were statistically different in more than one of the daily periods considered (24-hr, postprandial, interdigestive, nocturnal). Percent time of duodenogastric reflux is significantly higher in the antrum than in the fundus in both groups. Modalities of gastric alkalinization secondary to food or duodenogastric reflux were different for the fundus and for the antrum both in healthy and dyspeptic subjects and between the two groups. These differences suggest that single and multiple pH monitoring of the stomach have different indications, and the position of the probes should vary according to the purpose of the test.

Adult↗
PubMed1991

[Monitoring esophageal pressure: comparison of various methods and a unique solution].

Ambulatory monitoring of intraesophageal pressure requires probes and techniques which are different from those used in the laboratory approach. In particular the perfusion system for the measurement of the pressure is not suitable and the development of alternative solutions is mandatory. In this perspective an accurate analysis of the theoretical basis of different methods is necessary in order to avoid incorrect results and difficulties in the subsequent phase of analysis. A prototype probe, which is based on inextensible thin plastic balloons filled with oil or saline, was tested in comparison with traditional (perfused) and microtransducer systems to outline the positive and negative aspects of the solution. The results were satisfactory as regards linear output and frequency response up to 5 Hz for the prototype probe and even superior, for instance, to the response of the perfused system to applied pressure, whose curves of the four open tips resulted different, and to the response of Millar transducer. The new prototype probe seems to be adequate to the clinical and research needs.

Equipment Design↗
PubMed1991

[Intraoperative esophageal manometry].

Intraoperative manometry has been proposed as a supportive procedure during the execution of anti-reflux operations and in the surgical treatment of achalasia. This procedure is not necessary in preparing anti-reflux plasty such as Belsey or Nissen, the outcome of which depends mostly on the correct execution of the surgical technique. Utilization of intra-operative manometry provides considerable benefits during the surgical treatment of achalasia, both when executing the extra-mucous myotomy and for the correct preparation of the anti-reflux plasty according to Dor, which is associated to it. Manometric control has made it possible to define the various anatomical components that, at both the esophageal and gastric levels, constitute the area which functionally corresponds to the lower esophageal sphincter and therefore a correct execution of the myotomy. As demonstrated by the follow-up study of our surgical patients, the intraoperative manometric measurement of the strain and of the length of the anti-reflux plasty is the determining factor affecting outcome over time. The pressure is apt to decrease even 5 year after surgery; maintaining given length and strain standards when executing the plasty can prevent delayed complications, such as esophagitis from gastro-esophageal reflux.

Esophageal Achalasia↗
PubMed1991

[Definition of a normal tracing in pH monitoring].

The adoption of specific criteria for the reading of tracings, together with a comparison of the results obtained during the course of patient tests with the thresholds of normality calculated in groups of healthy volunteers, are required to determine the normality or abnormality of pH monitoring. From such comparisons performed among groups of healthy volunteers, selected especially on the basis of age or nationality, it was found that age bears no significant influence in calculating the parameters pertinent to pH monitoring. On the other hand, different dietary and life habits could be responsible for a few, albeit limited, discrepancies, such as, for instance, the number of recorded occurrences of gastro-esophageal acid reflux. Use of esophago-gastric pH monitoring, which makes it possible to identify both acid and non-acid gastro-esophageal reflux (mixed and alkaline), authorizes the diagnosis of that limited number of patients in whom this latter component of reflux only exceeds normal limits (3.3%) and an improved definition of the clinical picture in a larger share of patients (20%). Use of different statistical methods to calculate the thresholds of normalcy does not substantially improve the sensitivity of the examination, changing the thresholds by a few tenths of a unit and the fact that the examination is slightly over, or slightly under, the threshold being of ineffectual clinical significance. The study of the correlation between symptoms and pH monitoring events seems a valid interpretative criterion of these tests and capable of improving the diagnostic efficiency of the examination (0.88) when combined with mathematical evaluation.

Adult↗
PubMed1991

A simple method to detect contaminating peptides and amino acids in large-scale ganglioside preparations.

A reverse-phase liquid chromatography method was developed to analyse the presence of contaminating peptides and amino acids in large-scale monosialoganglioside preparations. Samples were hydrolysed under controlled conditions and derivatized with phenylisothiocyanate. PTC-amino acids were then separated and identified by HPLC. The sensitivity of the method allowed detection of a least 50 pmoles of amino acid per mg of ganglioside with excellent reproducibility and little or no interference of by-products derived from hydrolysis of the glycosphingolipid. The response was consistently linear for each amino acid within the examined analytical range. The ease and speed of performance make this method a useful tool for rapidly monitoring large-scale extraction and purification processes of biologicals obtained from natural sources.

Amino Acid Sequence↗
PubMed1991

Lithotripsy with a Q-switched alexandrite laser system. Preliminary in vivo and in vitro results.

An alexandrite laser system which emits a wavelength of 750 nm, has recently been proposed as a substitute for the pulsed-dye laser (504 nm) for laser lithotripsy. We have carried out in vitro lithotripsy trials in order to evaluate the efficiency of a flashlamp pumped Q-switched alexandrite laser. In the first experiment, we compared the Q-switched alexandrite laser to the pulsed-dye laser with respect to their effectiveness in fragmentizing urinary and model stones (HMT target stones). In the second experiment, we evaluated the effect of Q-switched alexandrite radiation on the urinary wall (bladder, ureter, renal pelvis and liver) of animals (Wistar rats and rabbits) under general anesthesia. In conclusion, the alexandrite laser system is comparable to the pulsed dye laser. The 750-nm wavelength involves minimal risk of damage to the urinary tract and constitutes a safe alternative, especially during blind lithotripsy. It is a compact solid-state system, with no toxic chemical agents as laser material.

Animals↗
PubMed1991

[Imaging techniques in the staging of carcinoma of the esophagus].

Forty-four patients affected with thoracic esophageal carcinoma underwent preoperative CT to evaluate the value of this method in both staging and assessing the resectability of esophageal tumors. The authors compared the CT findings with intraoperative macroscopic ones, pathologic, and bronchoscopic results in mid-high neoplasms. CT staging criteria were drawn from a careful review of literature and from personal experience. Thirty-nine patients were submitted to surgery, and esophagectomy was possible in 34 of them. CT diagnostic accuracy was higher in proximal esophageal tumors than in sub-bronchial ones; as for the surgical choice, CT provided fundamental guidelines, especially if the choice was a blunt esophagectomy where it is important to exclude tumoral involvement of the airways (accuracy: 82.6%) or of the aorta (accuracy: 89.7%). CT staging accuracy was limited by the low sensitivity of the method in detecting lymphatic (local: 66.6%, distant: 64.2%) and hepatic metastases. Combined thoraco-abdominal CT, tracheobronchoscopy and liver US, besides MR imaging and endoscopic US, allow a better preoperative evaluation of esophageal carcinomas.

Adenocarcinoma↗