In order to ensure a safe and effective procedure, an adjustment of the laser power to the decreasing penetration depth is recommended during therapy. These results provide a better understanding of laser-tissue interaction and may be helpful to investigators in the field of light dosimetry in liver tissue.

Hidradenitis suppurativa (HS) is a chronic fistula- and abscess-forming disease of the cutis and subcutis of unknown etiology. Disease recurrence is frequent and may cause severe complications. We analyzed patients with HS who underwent surgery between 1976 and 1997. The operative procedures were divided into drainage procedures (n = 6), limited regional (n = 14), and radical wide excisions (n = 11). The extent of surgery was examined in terms of the clinical course and late postoperative sequelae of HS. At a mean follow-up of 72 months, we found developed locoregional recurrent HS in 45% of patients. There was 100% recurrence after drainage, 42.8% after limited, and 27% after radical excision (P < 0.05). HS recurred after a median interval of 3 months for drainage, 11 months for limited excision, and 20 months for radical excision (P < 0.05). The disease-free interval continued up to 35 months. Long-term sequelae included penile amputation and a case of fatal squamous cell carcinoma. Although radical wide excision of the HS-affected cutis is associated with the lowest recurrence rate, it is still considerable and warrants long-term follow-up.

In the majority of patients, laparoscopic sigmoid resection in sigmoid diverticulitis can be performed without conversion. Patients who underwent surgery in the inflammation-free interval had a lower complication rate than those submitted to early elective resection. In our patient population, we were able to show that surgery in the inflammation-free interval significantly reduces postoperative morbidity. It is thus preferable for patients with sigmoid diverticulitis to receive initial antibiotic treatment and then undergo late elective laparoscopic sigmoid resection.

No abstract

Photodynamic therapy (PDT) is an alternative to radical surgical resection for T1a or nonresectable carcinomas of the gastroesophageal junction. Besides the concentration of the photosensitizer, the light distribution in tissue is responsible for tumor destruction. For this reason, knowledge about the behavior of light in healthy and dysplastic tissue is of great interest for careful irradiation scheduling. The aim of this study is to determine the optical parameters (OP) of healthy and carcinomatous tissue of the gastroesophageal junction in vitro to provide reproducible parameters for optimal dosimetry when applying PDT. A total of 36 tissue samples [adenocarcinoma tissue (n=21), squamous cell tissue (n=15)] are obtained from patients with carcinomas of the gastroesophageal junction. The optical parameters are measured in 10-nm steps using new integrating sphere spectrometers in the PDT-relevant wavelength range of 300 to 1140 nm and evaluated by inverse Monte-Carlo simulation. Additional examinations are done in healthy tissue from the surgical safety margin. In the wavelength range of frequently applied photosensitizers at 330, 630, and 650 nm, the absorption coefficient in tumor tissue (adenocarcinoma 1.22, 0.16, and 0.15 mm(-1); squamous cell carcinoma 1.48, 0.13, and 0.11 mm(-1)) is significantly lower than in healthy tissue (stomach 3.34, 0.26, and 0.20 mm(-1); esophagus 2.47, 0.21, and 0.18 mm(-1)). The scattering coefficient of all tissues decreases continuously with increasing wavelength (adenocarcinoma 22.8, 12.99, and 12.52 mm(-1); squamous cell carcinoma 19.44, 9.35, and 8.98 mm(-1); stomach 20.55, 13.96, and 13.94 mm(-1); esophagus 20.34, 12.56, and 12.22 mm(-1). All tissues show an anisotropy factor between 0.80 and 0.94 over the entire spectrum. The maximum optical penetration depth for all tissues is achieved in the range of 800 to 1100 nm. At the wavelength range of 330, 630, and 650 nm, the optical penetration depth is significantly higher in carcinoma tissue (adenocarcinoma 0.27, 1.54, and 1.66 mm; squamous cell carcinoma 0.23, 1.71, and 1.84 mm) than in healthy tissue (stomach 0.16, 1.10, and 1.26 mm; esophagus 0.17, 1.47, and 1.65 mm; p<0.05). Above 1000 nm, a higher absorption coefficient of tumor tissue results in a lower optical penetration depth than in healthy tissue (p<0.05). The higher absorption and scattering of the tumor tissue in the wavelength range of available photosensitizer is associated with a low optical penetration depth. This necessitates higher energy doses and long application times or repeated applications to effectively treat large tumor volumes. Photosensitizers optimized for larger wavelength range need to be developed to increase the efficacy of PDT.

No abstract

Regulatory (FOXP3 + ) T cells (T regs ) comprise a subpopulation of CD4I ntense research has shown that regulatory T cells (T regs ) play a fundamental role in providing peripheral tolerance against auto and foreign antigens, whereas impairment of T reg function seems to be associated with different autoimmune diseases like systemic lupus erythematodes,(1) type 1 diabetes, (2) rheumatoid arthritis (3,4) and multiple sclerosis.(5) Particularly stimulating for oncologic research was that increased frequencies of T regs with suppressive activity were found in malignant tumors and in the blood of cancer patients.(6-9) Blocking of T reg function in murine tumor models resulted in strong cellular antitumor immunity and even complete tumor destruction, (10)(11)(12)(13)(14)(15) indicating a crucial role for T regs in tumor immunity.T regs represent a subpopulation of CD4 + T cells and account for approximately 10-15% of all CD4 + T cells. The most specific marker for T regs currently available is the transcription regulator FOXP3. + T regs an evolutionary conserved region within the foxp3 locus upstream of exon-1 displays complete DNA demethylation, known as the T reg -specific demethylated region (TSDR), whereas T cells with transient FOXP3 expression and thus non-permanent suppressive function, such as transforming growth factor-β induced T regs and recently activated conventional human T cells show a fully methylated TSDR. (18)(19)(20)(21) Little is known about factors that mediate homing of T regs in different organs or tumor tissue, but experimental data suggest that an interaction between organ-specific factors and T regs is required for their expansion and homing. (22)(23)(24) A highly selective switch for specific inactivation of murine T regs was identified by Shimon Sakaguchi and his colleagues.(25) He developed an agonistic antibody that binds to murine glucocorticoidinduced tumor necrosis factor receptor family-related protein (GITR). Activation of GITR in concert with antigen-specific stimulation of T regs abrogates their suppressive activity. Applying the anti-GITR antibody to BALB/c mice 8 days after inoculation of 2 × 10 5 Meth-A fibrosarcoma cells induced a strong antitumor immune response followed by complete tumor eradication in all treated animals.(25) One concern regarding possible side-effects of GITR activation was the unintended induction of autoimmune reactions, but organ function in mice remained unaltered during therapy and no autoimmune reactions were detected. (25) Despite their viral origin and well-defined target genes, clinical trials for immune therapy of cervical intraepithelial neoplasia (CIN) lesions and cervical cancer have been mostly ineffective. (26)(27)(28)(29)(30)(31)(32)(33)(34)(35) Potentially acting as a tumor-protective shield, T reg may constitute an important reason for these failures, as their accumulation at the tumor site might render intended immunostimulation ineffective.In order to elucidate the prevalence of FOXP3 + T cells in CIN lesions, cervical cancer, colon can...

Due to the lack of comparable data, there is currently no reliable information on whether one treatment option is superior to the other. Regarding the limited applicability of EBD in strictures of the small bowel, only a controlled trial would provide evidence as a basis for clinical decision making in CD strictures that are potentially treatable by EBD and SP.