CTL and NK cells use two distinct cytocidal pathways: 1) perforin and granzyme based and 2) CD95L/CD95 mediated. The former requires perforin expression by the effectors (CTL or NK), whereas the latter requires CD95 (Fas/APO-1) expression by the target. We have investigated how these two factors contribute to tumor immune surveillance by studying the immunity of perforin-deficient mice against the progressor C57BL/6 Lewis lung carcinoma 3LL, which expresses no CD95 when cultured in vitro. Unexpectedly, the results indicated that the perforin-independent CD95L/CD95 pathway of CTL/NK plays a role in acting against D122 and Kb39.5 (39.5) high and low metastatic sublines, respectively, derived from the 3LL tumor. Although no membrane-bound CD95 was detected on cultured D122 and 39.5 cells, surface CD95 expression on both D122 and 39.5 was considerably up-regulated when the tumors were grown in vivo. A similarly enhanced expression of CD95 was observed with three additional tumors; LF−, BW, and P815, injected into syngeneic and allogeneic mice. The finding of up-regulated CD95 expression on tumor cells placed in vivo suggests that a CD95-based mechanism plays a role in tumor immunity at early stages of tumor growth. Consequently, the progressive down-regulation of CD95 expression during tumor progression may indeed be an escape mechanism as previously reported. Together, these results suggest a role for CD95-dependent, perforin-independent immunity against certain tumors.

Background: Cecal diverticulitis is frequently indistinguishable from acute appendicitis preoperatively and is sometimes mistaken for carcinoma at laparotomy. The surgeon must be aware of the possibility of diverticulitis of the cecum in the operating room and choose the appropriate treatment. Purpose: Because there is no universal therapeutic approach to these patients, we decided to assess the presenting symptoms, clinical findings, preoperative diagnosis, operative findings determining the proper management of these patients. Methods: A retrospective chart review of 13 patients with pathologically confirmed cecal diverticulitis, who underwent surgery in our department from 1984 to 1998, was undertaken. Results: The mean age of patients was 43.5 years. Right lower quadrant pain and local tenderness were the only clinical findings in 92.3%, with preoperative diagnosis of acute appendicitis in 84.6% of patients. The operative finding in most cases was inflammatory mass of the cecum; in 6 cases it was indistinguishable from perforated cecal carcinoma. Six patients underwent right hemicolectomy, 5 had ileocecectomy, 1 patient was treated by tube cecostomy, and 1 had diverticulectomy. There were three minor postoperative complications: pneumonia, wound infection and lower limb superficial thrombophlebitis. Conclusions: Cecal diverticulitis needs a high index of suspicion for achieving a preoperative diagnosis. We suggest that the operative therapy should be ileocecectomy. The surgical specimen should be examined during surgery and only if carcinoma is found should the patient have a formal colectomy.

Background The clinical presentation of acute appendicitis in the youngest age lacks specific signs and symptoms, and it is difficult to obtain an accurate clinical diagnosis. Once the diagnosis is made, it is necessary to determine if the appendicitis is simple and able to be managed non-surgically, or complicated, therefore requiring surgery. Together with the clinical picture and imaging, routine laboratory values play a vital role in this decision. The aim of this study is to evaluate routine blood in their ability to differentiate between complicated and uncomplicated acute appendicitis. Method A retrospective analysis was conducted from a single pediatric surgery department of all children 5 years of age or younger who underwent surgery for acute appendicitis between the years 2010-2020. Results 728 children were diagnosed with acute appendicitis, and 42 children were under the age of 5 years. There was a significant difference in the C-reactive protein, white blood cell count, neutrophil/lymphocyte ratio, and platelet/lymphocyte ratio in the complicated group versus the uncomplicated group. The value of these together for prediction complicated appendicitis were 84.8% sensitivity, 80.9% specificity, 82.8% positive predictive value, and 72.8% negative predictive value. These values were all higher than both the Alvarado score and the PAS ( P  <  .05). Conclusions C-reactive protein, neutrophil/lymphocyte ratio, and platelet/lymphocyte ratio are simple laboratory parameters that can help identify complicated versus uncomplicated appendicitis in children 5 years old or younger. These universal parameters may help guide the treatment and decision to operate on a difficult to diagnose population.

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