Chitin digestion by humans has generally been questioned or denied. Only recently chitinases have been found in several human tissues and their role has been associated with defense against parasite infections and to some allergic conditions. In this pilot study we tested the gastric juices of 25 Italian subjects on the artificial substrates 4-methylumbelliferyl-β-D-N,N’,diacetylchitobiose or/and fluorescein isothiocyanate (FITC) chitin to demonstrate the presence of a chitinase activity. Since this chitinase activity was demonstrated at acidic pH, it is currently referred to acidic mammalian chitinase (AMCase). AMCase activity was present in gastric juices of twenty of 25 Italian patients in a range of activity from 0.21 to 36.27 nmol/ml/h and from 8,881 to 1,254,782 fluorescence emission (CPS), according to the used methods. In the remaining five of 25 gastric juices, AMCase activity was almost absent in both assay methods. An allosamidine inhibition test and the measurement at different pH values confirmed that this activity was characteristic of AMCase. The absence of activity in 20% of the gastric juices may be a consequence of virtual absence of chitinous food in the Western diet.

Gastrointestinal stromal tumors (GISTs), tumors characterized by c-KIT mutations, are the most frequent mesenchymal tumors of the digestive tract. The stomach is the most commonly involved site. Localization, size and mitotic rate are reliable predictors of survival and the two milestones of GISTs treatment are surgery and imatinib. This article is aimed to report the data of an audit, carried out on the morphological and clinical aspects of the disease and to review the present knowledge on GISTs. A total of 172 patients with GISTs (M : F=1 : 1; mean age 65 years) were recruited. The stomach was the most frequently involved site. In 50% of the cases the tumor was smaller than 5 cm, whereas major symptoms were observed in 43% of the cases. Predictors of progressive disease were present only in a small percentage of cases but the disease was in the metastatic phase in over 25% of the cases at diagnosis. Familial aggregation was rare but a consistent share of the patients (21%) had other synchronous or metachronous cancers. The most frequent mutations were in-frame deletions and point mutations of c-KIT exon 11. This report confirms in part the available data on GIST in a consecutive series of patients recruited in Italy and shows that only large collaborative multicenter studies provide data sound enough to enable making reasonable clinical and therapeutic choices, and suggests that, as a measure of secondary prevention, a diagnostic definition should be obtained in all submucosal lesions of the GI tract and that GIST patients should be screened for second tumors.

In conclusion, BD stones can be endoscopically cleared preoperatively in most patients without interfering with LC.

We present our experience on lung and esophageal cancers treated by PDT. Since 1982, we have been using PDT in carcinomas of the head and neck, recurrences of gynecological tumors, skin cancers, and recurrences of brain tumors. We have treated the initial lesions of lung and esophageal cancers. From June 1989 to November 2004, 40 patients with 50 NSCLC were treated with PDT. Twelve cases were inoperable for medical reasons and were staged as T1N0M0, and 28 had recurrent in situ carcinoma. Patients with residual disease after PDT received definitive radiotherapy and/or brachytherapy. With PDT there was 72% complete response (CR) rate (36/50 treated lesions); that is, 27 CR among the 37 Tis carcinomas and 9 among the 13 T1 cases. Kaplan-Meier curves showed a mean overall survival (OS) of 75.59 months (median 91.4 months). Two- and 5-year OS rates were 72.78% and 59.55%, respectively. The mean and median survival rates for patients with Tis stage were 86.5 and 120.4 months, respectively (standard error 9.50), and for patients with T1 disease they were 45.78 and 35.71 months, respectively; the differences were statistically significant (P < 0.03). No severe early or late PDT-related adverse events were recorded. We report the effects of PDT on inoperable early-stage esophageal cancer. Sixty-two patients were treated with an argon dye laser (630-nm wavelength, 300−800 mW of power, energy dose of 200−300 J/cm2) after intravenous injection of 5 mg/kg of hematoporphyrin derivative. Eighteen patients (29.5%) had in situ carcinoma (Tis), 30 (48.5%) had T1-stage cancer, 7 (11%) had T2-stage cancer, and 7 (11%) had recurrent disease in the anastomotic area after previous surgery without evidence of invasion outside the lumen. The complete response (CR) rate was 37% (23 of 62) in patients who received PDT alone and 82% (51 of 62) in those who also received radiotherapy. The CR rate after PDT alone was statistically higher (p < 0.04) for patients who had Tis/T1 lesions (21 of 48; 44%) than for those with T2-stage disease (2 of 7; 28%) or recurrent tumors (0 of 7; 0%). Fifty-two percent of patients who had CR following PDT alone did not suffer local tumor recurrence. The median local progression-free survival times after PDT and additional radiotherapy (in cases with incomplete response) were 49 months for Tis- and T1-stage lesions, 30 months for those with T2-stage disease, and 14 months for patients with locally recurrent disease. Patients who completely responded to PDT had a median overall survival (OS) of 50 months, which was significantly longer (p < 0.003) than that of patients not responding to PDT. Toxicity was minimal; we recorded three cases of esophageal stenosis (7%) and one case of tracheo-esophageal fistula (2.5%) after combined PDT and radiotherapy. In conclusion, PDT is an effective regimen for early esophageal cancer and NSCLC, giving a good CR rate and long-term results with local control and favorable overall survival. Additional radiotherapy in cases of incomplete response to PDT is effective and potentiall...

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