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R Schiessel

Publications and source records attributed to R Schiessel.

At least 19 recordsLinked to original sources

MR imaging for the preoperative planning of sphincter-saving surgery for tumors of the lower third of the rectum: use of intravenous and endorectal contrast materials.

PURPOSE: To evaluate the value of magnetic resonance (MR) imaging with a flexible surface coil in predicting the resectability of tumors in the lower rectum and the feasibility of sphincteral salvage. MATERIALS AND METHODS: In a prospective study, 61 patients with histologically proved primary adenocarcinoma of the lower or middle third of the rectum (<12 cm from the pectinate line) were examined at double-contrast-material-enhanced MR imaging with a circular polarized flexible surface coil. RESULTS: Assessment of anal sphincteral infiltration at MR imaging was excellent, with a specificity of 98% and a sensitivity of 100%. In the determination of tumor infiltration into adjacent organs (T4), the specificity was 100%, and the sensitivity was 90%, with surgical and histologic findings as the standards. While MR imaging showed negative nodes in 40 patients (stage N0 at MR imaging), histologic examination showed negative nodes in 27 patients and positive nodes in 34. At MR imaging, sensitivity was 68%, and specificity was 24%. CONCLUSION: While preoperative staging at MR imaging according to the TNM system still has limited value and accuracy, MR imaging provides the surgeon with valuable information regarding the presence of sphincteral invasion and the surrounding structures in patients with cancers in the lower third of the rectum.

Adenocarcinoma↗

Preservation and restoration of sphincter function in patients with rectal cancer.

Radical resection of rectal cancer is the standard treatment for curing this disease. Half of these tumours are located in the rectosigmoid region or the upper third of the rectum and are, therefore, easily resectable with preservation of the sphincter muscles, thus guaranteeing acceptable continence in most patients. However, tumours that originate in the lower parts of the rectum have been accompanied with the need for an abdominoperineal resection and the threat of a permanent colostomy. In the past 20 years, sphincter-saving surgery has become increasingly common in the treatment of tumours of the middle and low rectum due to the knowledge of tumour growth, the use of stapling devices, and the knowledge of the physiology of the pelvic floor and the sphincter muscles, respectively. Recent surgical techniques of resection of the 'ultralow' rectum (intersphincteric resection) and the reconstruction by coloanal anastomosis are reviewed. Functional problems following ultralow resections are emphasized, as well as the possibility of sphincter restoration after abdominoperineal resection by use of dynamic graciloplasty. Taking all surgical options into account, a permanent colostomy for rectal cancer can be avoided in most curatively and electively operated patients.

Anal Canal↗

Needle perforation of the appendix.

BACKGROUND/AIMS: Needles are among the most frequently swallowed foreign bodies. In most cases they are excreted per vias naturales, but in some cases needles can lead to perforation of the stomach or duodenum in adults. METHODS: We report a case of acute appendicitis after perforation of the appendix by a swallowed needle. An appendectomy was performed without any knowledge of the reason for perforation. RESULTS: Inspection of the resected appendix demonstrated a needle of 1.5 cm length inside the lumen of the appendix, which had caused a perforation of the distal end of the appendix. CONCLUSION: As seen in this case a longer-lasting nondiagnosed perforation can lead to extensive local inflammation which could have been avoided by early surgical treatment which should also be considered if the patient has very few symptoms, as in this case.

Adult↗

Arterial supply of the gracilis muscle and its relevance for the dynamic graciloplasty.

The various methods of transposition of the gracilis muscle in order to serve as an anal neo-sphincter have progressed in recent years. Tetanic contraction can be achieved by converting Type II muscle fibers into Type I by use of chronic, low frequency electrical stimulation. In order to guarantee a good function the muscle's vascularization has to have at least one nutritive vessel. In our investigation we worked out the various forms of the muscle's arterial blood supply. Dissecting 66 specimens we detected four with only one nutritive vessel, 23 with a double-supply and, as the most common constellation, in 34 cases three supplying arteries. A small group of five individuals showed more than three arterial vessels. Because of the fact that the obturator nerve is not running with the incoming arteries, an angle was measured between the length axis of the muscle and the first perforating artery. This information should help the surgeon to preserve the nerve.

Aged↗

CD44 expression in benign and malignant colorectal polyps.

PURPOSE: This retrospective study was undertaken to evaluate immunohistochemically the expression of CD44 standard protein and CD44v5 and CD44v6 isoforms in colorectal adenomas and early invasive cancers developing within adenomas as possible markers characterizing colorectal polyps with a more aggressive biologic potential. METHODS: Archival tissues of 81 consecutive locally resected colorectal polyps, comprising 57 colorectal adenomas and 24 carcinomas-in-adenomas, were stained immunohistochemically with the use of commercially available mouse monoclonal antibodies: SFF-2 for CD44 standard protein, VFF-8 for CD44v5, and VFF-7 for CD44v6. RESULTS: Sixty-three percent of the colorectal polyps were positive for CD44 standard protein, 59 percent were positive for CD44v5, and 27 percent were positive for CD44v6. Ninety-three percent of the low-grade adenomas were CD44 standard protein-positive, in contrast to 50 percent of the high-grade adenomas and only 42 percent of the carcinomas-in-adenomas (Kendall's Tau = -0.42; P < 0.0001). CD44v6 expression was more frequently found in early invasive cancers (54 percent) than in high-grade adenomas (25 percent) and low-grade adenomas (7 percent). This difference also was statistically significant (Kendall's Tau-b = 0.39; P = 0.00003). Surprisingly, a downregulation of CD44 standard protein expression was observed in the adenoma tissue adjacent to carcinomas (62 percent) and areas with high-grade atypia (71 percent), compared with low-grade adenomas (93 percent; Kendall's Tau-b = -0.28; P = 0.004). CONCLUSIONS: Our data suggest that CD44 standard protein and CD44 isoform v6 expression differs considerably in benign and malignant colorectal polyps. Clinical studies with larger patient groups could clarify the prognostic potential of CD44 further.

Adenoma↗

Abdominosacral resection of recurrent rectal cancer in the sacrum.

PURPOSE: Resection of the sacrum is the only curative therapy of isolated sacral recurrence after primarily resected rectal cancer. The aim of the study was to assess whether there is a benefit in terms of overall survival, morbidity, and mortality when sacrum resection is performed more radically and in cooperation between colorectal and orthopedic surgeons. Possible prognostic factors were also assessed. METHODS: Twelve consecutive patients who underwent interdisciplinary partial sacral resection were included in a retrospective cohort study. Furthermore, overall survival rate and survival time were calculated. RESULTS: Histologic examination showed tumor-free resection margins in all cases. Extended resection was necessary in seven patients, including total pelvic exenteration in two. No perioperative death occurred and no patient required early reoperation. Complications were observed in 42 percent of patients, mainly caused by poor wound healing. All patients experienced relief from pain. One-year and three-year overall survival rates were 50 and 17 percent, respectively. The overall mean survival time was 21.7 months. Patients who died of recurrent disease within one year either underwent former resection for locoregional recurrence, had extensive local recurrent tumors affecting pelvic visceral structures, or retrospectively suffered from metastatic sacral tumor manifestation. CONCLUSION: The mortality and morbidity rates observed in the present study seem to justify partial sacral resection as a means to achieve palliation of perineosacral pain in spite of rare overall long-term survival.

Adenocarcinoma↗

Quality of life after surgery for rectal cancer: do we still need a permanent colostomy?

INTRODUCTION: A permanent colostomy is a serious limitation of the quality of life. Besides cure of cancer, preservation of sphincter function is an important goal of surgery for rectal cancer. METHODS: In a prospective study a concept offering every patient with rectal cancer either sphincter salvage or a "neosphincter" was investigated, and the impact of this strategy on oncologic results, sphincter function, and quality of life was analyzed. RESULTS: From 1992 to 1997, 276 patients were accepted for the study. Two hundred sixty-one patients had elective surgery, and 15 patients had emergency surgery for their rectal tumors. The postoperative mortality rate was 4 percent. A radical resection (R0) was possible in 197 patients (75 percent). Anterior resection was the most common procedure (n = 87), and intersphincteric resection with coloanal anastomosis was the preferred method for low tumors (n = 65). Abdominoperineal resection was necessary in 15 cases. Thirteen patients had an immediate restoration of sphincter function by means of a dynamic graciloplasty, and 2 patients needed emergency abdominoperineal resection for bleeding. The follow-up was relatively short (median, 36.4 months) at the time of data analysis and showed a local recurrence rate of 8 percent. Although postoperative continence according to the Williams score revealed satisfactory results, subjective quality of life and the scale for specific symptoms showed a significantly worse outcome in patients with ultralow (coloanal) anastomoses compared with those with anterior resection. CONCLUSIONS: We conclude that for elective curative surgery of rectal cancer, a permanent colostomy is not necessary provided all presently available techniques of sphincter salvage and restoration are applied. However, the patient has to be informed about possible side effects associated with surgical procedures such as coloanal anastomosis or neosphincter reconstruction, to avoid severe psychological difficulties.

Aged↗

[Anal sphincter restoration using dynamic graciloplasty--results of 50 patients].

During the period from 1992 to 1998, 50 patients underwent anal sphincter restoration by dynamic graciloplasty for primary (n = 26) or secondary (n = 6) total anorectal reconstruction (TAR) following abdominoperineal rectal resection (APR) or acquired (n = 9) or congenital (n = 9) fecal incontinence, respectively. Forty-seven patients were operated on by a single-stage procedure using a modified technique for the muscle wrap ("split sling"). Muscle fiber transformation by controlled stimulation was achieved at the beginning of the learning curve within 8 weeks and in the meantime within 4 weeks. Rectal injury (n = 10) turned out to be the most serious postoperative complication and was observed mainly in patients following TAR (n = 8). As the most prominent functional problem constipation in patients following TAR hampered the postoperative functional result; however, this was overcome by regular enemas. An improvement in the continence status was observed in 80% of the patients treated for fecal incontinence, and following APR 66% of the patients had acceptable results without a permanent colostomy.

Adolescent↗

[Loop enterostomy].

Intestinal stomas are widely used in the treatment of colorectal disease since they are relatively easy to construct and are supposed to increase the safety of colorectal surgery. During the past 50 years there have been several improvements in operative technique and stoma management but despite these advances there remains appreciable morbidity associated with the construction of stomas. Increasing awareness of the morbidity associated with enteral stomas has led to greater questioning of the need for temporary stomas. This paper reviews the indications and surgical technique as well as the morbidity associated with loop colostomy and ileostomy.

Colostomy↗

Activated lymphocytes from breast cancer patients express the characteristics of type 2 helper cells--a possible role for breast cancer-associated p43.

P43, a breast cancer-associated antigen, has been repeatedly described as an immunosuppressive factor. The objective of the present study was to investigate whether immune dysregulation induced by p43 affects the profile of cytokines secreted by mitogen-stimulated lymphocytes in breast cancer patients as compared with stimulated lymphocytes in women with benign tumors. The study consisted of 32 women undergoing surgical excision for a suspicious lesion in their breast. Histology revealed malignant breast disease in 20 patients and benign lesions in 10 patients. Lymphocytes isolated from peripheral blood were activated by Conconavalin A (Con A) with and without the addition of p43 and the concentrations of cytokines (IL-2, TNF-alpha, IFN-gamma, IL-4, IL-10 and IL-6) secreted into the culture medium were determined. Lymphocytes of patients with malignant breast disease stimulated with Con A secreted a significantly higher concentration of IL-10 compared with lymphocytes of patients with benign tumors. No significant differences were found between the two groups regarding the levels of IL-2, TNF-alpha, IFN-gamma and IL-4. Cytokine concentrations were analyzed according to the type 1/type 2 cytokine profile (IL-2, TNF and IFN-gamma and IL-4, IL-6 and IL-10, respectively). This analysis revealed no significant differences in IL-2, TNF or IFN-gamma between benign and malignant tumors. However, in the type 2 cytokines, lymphocytes from cancer patients secreted significantly higher levels of IL-4 (27.3 +/- 7.2 U/ml) and IL-10 (44.1 +/- 22.3 U/ml) than did the lymphocytes from patients with benign disease (21.4 +/- 7.3 and 1.8 +/- 0.3 U/ml, respectively). The addition of p43 to the culture medium significantly enhanced the levels of IL-4 secreted by lymphocytes in both groups of patients (malignant disease, from 27.3 +/- 9.2 to 40.7 +/- 6.3 U/ml; benign disease, from 21.4 +/- 7.3 to 28.4 +/- 2.1 U/ml). P43 antigen significantly enhanced the low levels of IL-10 in the benign lymphocytes (from 1.8 +/- 0.4 to 8.4 +/- 1.5 U/ml) while the high levels of IL-10 secreted by the PBL in patients with malignant tumors were not significantly increased (44.1 +/- 22.3 versus 50.1 +/- 12.6 U/ml). The study showed a difference in the immune response of lymphocytes between malignant and benign tumors. When the current results were analyzed according to the type of response, i.e. in terms of whether at least two cytokines of either type 1 or type 2 were elevated, a significant type 2 response was observed in the PBL of patients with malignant breast cancer (IL-10 and IL-4). These results may explain why antitumor response is impaired in patients with breast cancer.

Antigens, Neoplasm↗

Restoration of anal sphincter function by single-stage dynamic graciloplasty with a modified (split sling) technique.

BACKGROUND: Controlled muscle fiber conversion by electrostimulation makes transformation of fast twitching type II muscle fibers to slow twitching type I fibers possible, which gives skeletal muscles the capacity for tetanic contraction. This phenomenon has been recently applied in the so-called "dynamic graciloplasty" to restore function of an insufficient or excised anal sphincter. This paper describes our results with this method in patients with fecal incontinence or following an abdomino-perineal resection (APR) of the anorectum. METHODS: From April 1992 through April 1997, 28 patients (12 women and 16 men) were treated by dynamic graciloplasty. The median age was 53.5 years (range 16 to 79). Indications were as follows: APR + synchronous restoration of the excised sphincter by graciloplasty (n = 12); total anorectal reconstruction (TAR) following APR in the past (n = 6); Patients with acquired fecal incontinence (n = 4); and Congenital atresia (n = 6). Muscle transposition, implantation of stimulation electrodes and pulse generator were done as a single-stage procedure, the "neosphincter" was wrapped in a modified technique (split-sling technique). Muscle transformation was performed by controlled neuromuscular stimulation during 8 weeks (from 1992 to 1995) and 4 weeks (since 1996), respectively. RESULTS: No postoperative mortality (90 days) was observed in either group. In our early experience, rectal injury occurred in 4 patients as the most prominent complication. Evaluation of the functional outcome showed the best results in patients operated either for congenital of acquired incontinence who achieved a continence for solids and liquids or solids alone, respectively (1 or 2 according to Williams' score) in 90%, while patients following APR showed a satisfying outcome (continence for solids and liquids, solids alone or with occasional episodes for liquids) in only 55.5%. In patients following APR, defecation disorders turned out to be the most prominent functional problem and had to be treated by enemas. CONCLUSION: In this series, we have been able to perform dynamic graciloplasty as a one-stage procedure using a modified muscle wrap (split-sling-technique) thus reducing the time period until continence could be achieved to 7 weeks. We found the appropriate tension of the muscle wrap essential to prevent direct injury to the rectum as it was seen in our early experience. For this reason, we have introduced a modified device to perform intraoperative anal manometry and to measure pressures created by the neosphincter objectively.

Adolescent↗

Muscle transformation of the sartorius muscle in a canine model: clinical impact for electrodynamic graciloplasty as a "neosphincter".

PURPOSE: Transformation of fast-twitching skeletal muscles to slow-twitching, slowly fatigable muscles has become of clinical interest in the recent past. Transposition and transformation of the gracilis muscle to use it as a substitute for a resected or defected anal sphincter (graciloplasty) have been reported as achieving promising results in the treatment of fecal incontinence caused by sphincter defects or following abdominoperineal anorectal excision for cancer. METHOD: This experimental study used a canine model and the sartorius muscle to evaluate the functional efficiency of two different configurations of the muscle loop to compare the presently applied transformation program (8 weeks) with a shorter (5 weeks) protocol. In six beagle dogs, both sartorius muscles were wrapped around two stomas, either in an alpha fashion or in the so-called split-sling technique. Muscle transformation was achieved by controlled neuromuscular stimulation either during eight (Program A) or five weeks (Program B). After completion of the transformation period, the function of the muscle slings was evaluated by manometry, and histomorphologic evaluation of the sartorius muscles was performed. RESULTS: It was shown that muscle transformation led to a slowly fatigable muscle that made it possible to perform continuos (tetanic) contraction, regardless of the configuration or the duration of the transformation. Median pressures created by these muscles also did not differ significantly. In accordance with these functional findings, the histologic evaluation showed the typical, significant increase of Type I fibers in both muscle slings and following both transformation protocols. Although the decrease of fast-twitching Type II fibers was more pronounced following the conventional (8 weeks) program, this finding did not influence the functional results. CONCLUSIONS: Results of our experiment indicate the possibility for using a shorter transformation protocol for transformation of the gracilis muscle during graciloplasty in the clinical setting. Furthermore, the efficacy and safety of the modified (split-sling) wrap technique was demonstrated.

Anal Canal↗

Effect of growth factors on epithelial restitution of human colonic mucosa in vitro.

BACKGROUND: Epithelial restitution enables resurfacing of epithelial discontinuities by enterocyte migration. This study investigated the effect of basic fibroblast growth factor (bFGF), insulin-like growth factor (IGF-1), and epidermal growth factor (EGF) on restitution of human colonic mucosa in vitro. METHODS: After base-line incubation human colonic mucosal strips, mounted in Ussing chambers, were luminally exposed to 0.5 mM sodium deoxycholate (NaDOC) for 10 min. Thereafter tissues were incubated with buffer alone or luminal buffer containing various concentrations of bFGF, IGF-1, and EGF for 3 h. Resistance (R) was calculated from potential difference (PD) and short-circuit current (Isc). All tissues were processed for light microscopy. Extent of damage was measured by morphometry. RESULTS: Luminal 0.5 mM NaDOC for 10 min caused R to drop by 43% (n = 4; P < 0.05). Compared with controls 50 ng/ml EGF induced an approximately 30% R increase until the end of the experiments (P < 0.05, n = 4, paired). Ten minutes after injury 50.2 +/- 4% of the mucosa was damaged (n = 6), and after 3 h damage was significantly reduced by EGF (17.2 +/- 3% versus 31.7 +/- 4%, 50 ng/ml EGF versus controls) (P < 0.05, n = 6 per group). Histology showed that EGF stimulated enterocyte migration over the basal lamina. Various doses of bFGF and IGF-1 did not impair restitution when compared with controls. CONCLUSION: In contrast to bFGF and IGF-1, EGF was shown to promote epithelial restitution of human colonic mucosa in vitro.

Colon↗

Effective radiochemotherapy with cisplatin and etoposide for the management of patients with locally inoperable and metastatic esophageal carcinoma.

BACKGROUND: The limited therapeutic value of available chemotherapeutic drug combinations in patients with advanced esophageal carcinoma, the documented synergistic activity of etoposide and cisplatin, which might be further enhanced by simultaneous radiotherapy, and promising though only preliminary therapeutic results with this combination regimen have stimulated the present Phase II trial. The specific aim of the study was to determine the efficacy and tolerance of this combined treatment approach in previously untreated patients with either local regional unresectable or metastatic esophageal carcinoma. METHODS: Thirty patients with Stage IIIB or IV squamous cell or adenocarcinoma of the esophagus were entered in this study between October 1992 and November 1994. Chemotherapy was comprised of cisplatin, 30 mg/m2, combined with etoposide, 120 mg/m2, both given intravenously on 4 consecutive days. Treatment courses were repeated every 4 weeks. Radiation therapy (total dose, 5000 centigray) was administered concurrently during the 2nd and 3rd chemotherapy course, during which both drugs were given with a 25% dose reduction. RESULTS: After a median of 4 chemotherapeutic treatment courses (range, 1 to 6 courses), 3 patients had a complete response for 5, 8, and 11.5 months, and 9 patients had a partial response lasting for a median duration of 5.3 months (range, 2.5 to 7.5 months), yielding an overall response rate of 40% (95% confidence interval, 23-59%). The response rates tended to be higher for squamous cell carcinomas (11 of 23; 48%) than for adenocarcinomas (1 of 7), as well as for locoregional disease (7 of 13; 54%) than for patients with disseminated disease (5 of 17; 29%). For the entire study population, median time to progression was 5.4 months (range, 1.5 to 13.5 months), and median survival was 9.2 months (range, 1.5 to 28 months), with 4 patients still alive at the time of this report. Clinically, the most important toxic effect was myelosuppression. Grade 3-4 granulocytopenia occurred in 16 patients (53%), severe thrombocytopenia in 11 (37%), and Grade 3 anemia in 5 (17%). There were four hospitalizations among three patients for the management of fever during neutropenia. Other nonhematologic side effects were generally mild or modest, and most commonly included nausea/emesis (40%), mucositis and/or esophagitis during simultaneous radiotherapy (40%), and alopecia (43%). CONCLUSIONS: Combined radiochemotherapy with cisplatin and etoposide is active against advanced esophageal carcinoma, but can be associated with significant hematotoxicity. Although the therapeutic potential of this regimen appears to be comparable to other, conventional fluorouracil/cisplatin-based chemotherapy, less toxic and more effective regimens need to be identified.

Adenocarcinoma↗

Effects of extracellular pH on intracellular pH-regulation and growth in a human colon carcinoma cell-line.

Mechanisms of intracellular pH (pHi) regulation seem to be involved in cellular growth and cell division. Little is known about how extracellular acidosis, known to occur in central regions of solid tumors, or alkaline conditions affect pHi regulation in colonic tumors. pHi changes in the colonic adenocarcinoma cell-line SW-620 were recorded by spectrofluorimetric monitoring of the pH-sensitive, fluorescent dye BCECF, and proliferative activity was assessed by [3H]thymidine uptake. Resting pHi in Hepes-buffered solution was 7.53 +/- 0.01 (n = 36). Both 1 mM amiloride and Na(+)-free solution inhibited pHi recovery from acidification and decreased pHi in resting cells. In HCO3-/CO2-buffered media resting pH1 was 7.42 +/- 0.01 (n = 36). Recovery from acidification was Na(+)-dependent, CI(-)-independent, and only partially blocked by 1 mM amiloride. In the presence of amiloride and 200 microM H2DIDS pHi recovery was completely inhibited. In Na(+)-free solution pHi decreased from 7.44 +/- 0.04 to 7.29 +/- 0.03 (n = 6) and no alkalinization was observed in CI(-)-free medium. Addition of 5 microM tributyltin bromide (an anion/OH-exchange ionophore) caused pHi to decrease from 7.43 +/- 0.05 to 7.17 +/- 0.08 (n = 5). The effects of pH0 on steady-state pHi, pHi recovery from acidification and proliferative activity after 48 h were investigated by changing buffer [CO2] and [HCO3-]. In general, increases in pH0 between 6.7 and 7.4 increased pHi recovery, steady-state pHi and growth rates. In summary, SW-620 cells have a resting pHi > 7.4 at 25 degrees C, which is higher than other intestinal cells. Acid extrusion in physiological bicarbonate media is accomplished by a pHi-sensitive Na+/H+ exchanger and a pHi-insensitive Na(+)-HCO3-cotransporter, both of which are operational in control cells at the resting pHi. No evidence for activity of a CI-/HCO3- exchanger was found in these cells, which could account for the high pHi observed and may explain why the cells continue to grow in acidic tumor environments.

4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid↗

Immunosuppression by breast cancer associated p43-effect of immunomodulators.

It has been previously shown that p43- a breast cancer associated antigen-has immunosuppressive properties. The present study was carried out in order to elucidate the pathomechanisms of immunosuppression in breast cancer patients influenced by the expression of p43. Lymphocytes were cultured from blood of 29 women with benign lesions in the breast as well as from 41 female patients with breast cancer. Lymphocyte stimulation was performed by addition of Concanavalin (Con A) in cultures with lymphocytes alone (CONLYM) or in lymphocytes incubated with p43 (CONAg). In other series immunomodulation was tried by addition of indomethacin (INDLYM, INDAg), levamisole (LEVLYM, LEVAg), or interleukin-2 (ILLYM, ILAG). In breast cancer patients, addition of p43 significantly inhibited the activation of lymphocyte proliferation by Con A compared to women with benign tumors. The addition of indomethacin or levamisole did not influence this inhibitory effect of p43 in breast cancer patients. Contrary to these observations, addition of IL-2 resulted in increased proliferation of lymphocytes from patients with benign as well as malignant tumors, which was inhibited after addition of p43. Analysis of the correlation of the immunosuppressive properties of p43 in correlation with prognostic factors for breast cancer showed evidence for a stronger activity of p43 in early stage tumors (i.e. smaller than 2 cm, lymph node negative, histologic grading GI), confirming previous observations of a higher expression of p43 in early stages of breast cancer.

Adjuvants, Immunologic↗

Epidermal growth factor promotes rapid response to epithelial injury in rabbit duodenum in vitro.

BACKGROUND & AIMS: Growth factors are mainly involved in the regulation of intestinal epithelial barrier function. This study investigated the effect of epidermal growth factor (EGF) and insulin-like growth factor 1 (IGF-1) on epithelial restitution of rabbit duodenum in vitro. METHODS: Rabbit duodenal mucosal strips mounted in an Ussing chamber were luminally exposed to 10 mmol/L HCl for 10 minutes and then incubated with buffer alone or luminal buffer containing various concentrations of EGF and IGF-1 for 3 hours. Resistance was calculated from potential difference and short-circuit current. Damage was assessed by morphometry on H&E-stained sections. RESULTS: HCl caused resistance to decrease from 112 +/- 2 to 51 +/- 4 ohms x cm2 10 minutes after injury (n = 6; P < 0.05). Postinjury treatment with 25 or 50 ng/mL luminal EGF for 3 hours stimulated resistance to recover to 94 +/- 3 and 104 +/- 3 ohms x cm2, respectively, vs. 81 +/- 3 omega x cm2 in controls (P < 0.05). Ten minutes after injury, 62% of the mucosa was damaged; 3 hours after injury, damage was reduced to 24% +/- 1.09% and 10% +/- 1.42% in the 25 and 50 ng/mL EGF group, respectively, vs. 38% +/- 0.93% in controls (n = 6 per group). EGF stimulated enterocyte migration. IGF-1 did not impair epithelial restitution. CONCLUSIONS: EGF, but not IGF-1, promoted epithelial restitution of rabbit duodenum in vitro.

Animals↗

Laminin stimulates rapid epithelial restitution of rabbit duodenal mucosa in vitro.

BACKGROUND: This study investigated the effect of the basal lamina constituents fibronectin, collagen IV, and laminin on epithelial restitution of rabbit duodenum in vitro. METHODS: Rabbit duodenal mucosal sheets were mounted in Ussing chambers, luminally exposed to 10 mM HCI for 10 min, and incubated with buffer or luminal buffer containing 25-100 micrograms/ml of collagen IV, fibronectin, laminin, or polyclonal antisera directed against these proteins (diluted 1:50-1:20) for 3 h. Resistance was calculated from potential difference and short-circuit current. Mucosal damage was assessed by morphometry on hematoxylin- and eosin-stained sections. RESULTS: Acid exposure caused a 40% drop in resistance (119 +/- 5 versus 71 +/- 5 Ohm.cm2 before versus after injury; P < 0.05, n = 6) and mucosal damage of 58 +/- 4% (n = 6). Three hours after injury resistance was 102 +/- 6, 117 +/- 4, and 48 +/- 5 Ohm.cm2 in the control, laminin, and anti-laminin groups, respectively. Furthermore, 36 +/- 2%, 16 +/- 2%, and 64 +/- 5% of the mucosa was damaged in the control, laminin, and anti-laminin groups, respectively, 3 h after injury (P < 0.05 versus controls). Laminin promoted epithelial wound closure by stimulation of enterocyte migration, which was inhibited by anti-laminin. Fibronectin, collagen IV, anti-fibronectin, and anti-collagen IV did not impair restitution. CONCLUSION: Our results show that laminin promotes electrophysiologic restoration and epithelial restitution of rabbit duodenum in vitro. We therefore suggest that laminin plays an important part in the orchestration of epithelial integrity and barrier function.

Animals↗