Photodynamic therapy in normal pig stomach: protective effect of octreotide

BACKGROUND AND STUDY AIMS

Many factors, such as oxygen and vasculature, are involved in the cytotoxic effect of photodynamic therapy (PDT). It is known that somatostatin and its analog octreotide decrease the splanchnic blood flow and have multiple inhibitory effects in different functions of the peptic system. The aim of this experimental study was to assess the effect of octreotide administration on PDT outcome in normal pig stomach.

METHODS

28 healthy pigs, randomly assigned to two groups, A and B, were studied. Pigs in both groups were sensitized with 0.3 mg/kg intravenous meta-tetra (hydroxyphenyl) chlorin (m-THPC), and 48 hours later light of wavelength 650 nm was delivered from a 50-mW diode laser for 300 s (energy fluence 15 J/cm (2)) through a gastroscope to the gastric mucosa. Group A underwent PDT without octreotide and group B had PDT with administration of octreotide. At 72 h after light delivery, all the animals were sacrificed for macroscopic and histological evaluation of the irradiated site.

RESULTS

The macroscopic images and the histology of the stomach PDT lesions (inflammation, ulceration, necrosis) showed significantly less severity in the group of animals with octreotide injection (group B). In this group, full-thickness necrosis was observed in 28.5 %, compared with over 71.4 % in group A; this was statistically significant ( P < 0.05).

CONCLUSION

Octreotide may have a modulating effect on m-TPHC PDT in normal gastric tissue in pigs, probably due to alterations of hemodynamics in the stomach and to suppression of the inflammatory process.

B2 microglobulin: is it a reliable marker of activity in inflammatory bowel disease?

OBJECTIVES

The aims of this study were to investigate a possible positive correlation between B2-microglobulin (B2-M) serum levels and the severity and activity of inflammatory bowel disease (IBD); and to examine whether B2-M levels reflect IBD extent.

METHODS

We examined B2-M serum levels in 87 ulcerative colitis (UC) patients, 74 with Crohn's disease (CD) and 68 control subjects, using an enzymatic method. The reliability of the measuring method was assessed by evaluating serum B2-M in 18 patients suffering from chronic renal failure (CRF). The severity and activity of IBD was estimated using the van Hees Activity Index and the True-love-Witts criteria for CD and UC patients respectively. Endoscopic evaluation for UC patients was done according to Baron's et al. classification; Riley's et al. criteria were used for histological evaluation.

RESULTS

B2-M serum levels were significantly increased in all CD patients except those in remission. After 6 months treatment a second blood sample taken from CD patients with initially elevated B2-M levels proved to be compatible with CD severity at that time. Such a positive correlation was not assessed in UC patients; therefore, a second blood sample was considered unnecessary. Furthermore, CD patients with pancolitis, ileal-caecal, or small intestinal disease had higher B2-M levels than those with left-sided, anal, or perianal disease.

CONCLUSIONS

B2-M serum levels could prove to be a useful marker in assessing not only the activity, severity, and extent of CD but the treatment efficacy as well.

Colonic tuberculosis and adenocarcinoma: an unusual presentation

A case is presented of caecal tuberculosis coexisting with adenocarcinoma at the same site, unusually presenting as a right iliac fossa abscess. The relevant literature on 61 previously reported patients with coexisting tuberculosis and colonic carcinoma is reviewed. The patient was 81-years-old, female with a tender swelling in the right iliac fossa. Following examination by ultrasound, laparotomy was undertaken which revealed a large abscess cavity contaminated by Mycobacterium tuberculosis. Although anti-tuberculosis treatment was given, there was a persistent purulent discharge from the wound, so a new ultrasound, computed tomography scan and barium enema were arranged. These could not clearly differentiate between ileocaecal tuberculosis and carcinoma. A second laparotomy showed that there was an underlying adenocarcinoma. Although rare, the coexistence of colonic tuberculosis with carcinoma should be seriously considered especially in patients who fail to respond to anti-tuberculosis treatment. A definitive diagnosis can be established only by histological examination.