Pasteurella pseudotuberculosis infection in man. (1/24)

Pasteurella pseudotuberculosis has been considered a widespread animal pathogen for many years, but only within the last decade has its capacity to cause human disease been recognized. Two forms of human disease have been established-acute septicemia and mesenteric lymphadenitis. Because mesenteric adenitis is frequently indistinguishable from acute appendicitis, blood serum was obtained from 66 consecutive patients who underwent operation for appendicitis and was examined for agglutinins to seven serotype strains of P. pseudotuberculosis. Agglutinins were obtained in 21.2% of this series. Titres of over 1/100 were found in three of three cases of mesenteric lymphadenitis, one of 11 with no apparent disease, and one of 46 with appendicitis. P. pseudotuberculosis was isolated from a lymph node in the latter case. Two to four follow-up samples of sera in each of these five cases had increasing and then decreasing titres, indicative of active disease. Titres of 1/15 or less were found in five of the cases of appendicitis, in one case of salpingitis, and in three with no apparent disease. The occurrence of these nine cases with low titres may be indicative of previous contact with the organism.Human infection with P. pseudotuberculosis is not unusual in the Edmonton region and is responsible for at least some cases of mesenteric lymphadenitis.  (+info)

Increased through-transmission in abdominal tuberculous lymphadenitis. (2/24)

OBJECTIVE: To describe 2 cases of abdominal tuberculosis in which sonographic evaluation of mesenteric lymphadenopathy showed increased through-transmission suggestive of caseating necrosis. METHODS: Two patients with abdominal pain and other symptoms (including fever, diarrhea, and weight loss) underwent abdominal sonography with a 6-MHz curved array transducer. One patient also underwent sonographically guided fine-needle aspiration of multiple lymph nodes, and the other underwent computed tomography, colonoscopy, and colon biopsy. RESULTS: In both patients, sonography showed multiple rounded hypoechoic lesions with increased ultrasound through-transmission suggestive of necrotic lymphadenopathy. No color flow was shown. In 1 case, the posterior acoustic enhancement was accentuated in the harmonic imaging mode. In the other case, the lesions shown on sonography corresponded to computed tomographic findings of low-density lymph nodes. Results of fine-needle aspiration and colon biopsy were positive for tuberculosis. CONCLUSIONS: Posterior acoustic enhancement in abdominal lymphadenopathy can suggest the diagnosis of tuberculous lymphadenitis. Detection of this finding is facilitated by scanning in the harmonic mode. Necrotic nodes will lack color flow and can be distinguished from lymphadenopathy of other causes. Sonography can also be used for fine-needle aspiration of necrotic nodes to yield a definitive diagnosis.  (+info)

Mesenteric adenitis caused by Yersinia pseudotubercolosis in a patient subsequently diagnosed with Crohn's disease of the terminal ileum. (3/24)

Although the association between inflammatory bowel disease and gastrointestinal infections has been suggested, the mechanisms involved in the pathogenesis of Crohn's disease (CD) are still undetermined. We report the case of a man, who presented with mesenteric adenitis initially due to a Yersinia pseudotubercolosis infection, who was later diagnosed with Crohn's disease. This case is in keeping with recent evidence in the literature which suggests that CD is a disease linked to abnormal immune responses to enteric bacteria in genetically susceptible individuals.  (+info)

Importance of sonographic detection of enlarged abdominal lymph nodes in children. (4/24)

OBJECTIVE: Abdominal lymph nodes are frequently visualized by sonography in the pediatric population. The term "mesenteric lymphadenitis" is frequently used in the radiologic literature to describe this finding, whereas in the pediatric literature, this term is reserved for specific inflammation of the lymph nodes. The purpose of this study was to compare by sonography the incidence of appearance of enlarged abdominal lymph nodes (EALNs) in healthy children compared with that in children with abdominal pain of various causes. METHODS: In 200 patients referred for abdominal sonography for various indications, the presence of EALNs, their location, and size were registered. The patients were divided into 3 groups: those with abdominal pain due to an acute abdominal condition (group 1), those with abdominal pain without an acute abdominal condition (group 2), and asymptomatic patients (group 3). RESULTS: Enlarged abdominal lymph nodes greater than 5 mm were detected in 83.3% of group 1 patients, 73.8% of group 2 patients, and 64% of group 3 patients. A significant statistical difference was found between patients with abdominal pain and asymptomatic children only for lymph nodes of 10 mm and larger (P = .0117). No statistically significant difference was seen in the presence of lymph node clusters between the patients with abdominal pain and asymptomatic children. There was a tendency of increased EALN occurrence with age, peaking at 10 years, with a decrease later. CONCLUSIONS: Enlarged abdominal lymph nodes are frequently encountered in asymptomatic children and should not always be considered abnormal. Enlarged abdominal lymph nodes exceeding 10 mm in their shortest axis in children with abdominal pain may represent mesenteric lymphadenitis of various causes.  (+info)

The risk of developing Crohn's disease after an appendectomy: a population-based cohort study in Sweden and Denmark. (5/24)

BACKGROUND: The relationship between appendectomy and Crohn's disease is controversial. A Swedish-Danish cohort study was conducted to assess the risk of developing Crohn's disease after an appendectomy. METHODS: 709 353 appendectomy patients in Sweden (since 1964) and Denmark (since 1977) were followed for first hospitalisations for Crohn's disease to 2004. Standardised incidence ratios (SIR) served as relative risks. RESULTS: Overall, 1655 Crohn's disease cases were observed during 11.1 million person-years of follow-up. Whereas appendectomy before the age of 10 years was not associated with the risk of Crohn's disease (SIR 1.00; 95% CI 0.80-1.25), the overall SIR of developing Crohn's disease was 1.52 (95% CI 1.45-1.59), being highest in the first 6 months (SIR 8.69; 95% CI 7.68-9.84). SIR diminished rapidly thereafter, with the risk of Crohn's disease reaching background levels after 5-10 years for Crohn's disease overall, as well as for Crohn's ileitis, ileocolonic Crohn's disease, Crohn's colitis and other/unspecified Crohn's disease. A long-term increased risk of Crohn's disease up to 20 years after the appendectomy was seen only in appendectomy patients without appendicitis or mesenteric lymphadenitis. CONCLUSION: The transient increased risk of Crohn's disease after an appendectomy is probably explained by diagnostic bias.  (+info)

A role for natural killer cells in intestinal inflammation caused by infection with Salmonella enterica serovar Typhimurium. (6/24)

Acute gastroenteritis caused by Salmonella infection is a significant public health problem. Using a mouse model of this condition, the authors demonstrated previously that the cytokine gamma interferon (IFN-gamma) is required for a normal intestinal inflammatory response to the pathogen. In the present study, these experiments are extended to show that natural killer (NK) cells constitute an early source of intestinal IFN-gamma during Salmonella infection, and that these cells have a significant impact on intestinal inflammation. It was found that infection of mice with Salmonella increased both intestinal IFN-gamma production and the numbers of NK cells in the intestine and mesenteric lymph nodes. NK cells, along with other types of lymphocytes, produced IFN-gamma in response to the bacteria in vitro, while antibody-mediated depletion of NK cells in vivo resulted in a significant reduction in Salmonella-induced intestinal IFN-gamma expression. In a mouse strain lacking NK cells and T and B lymphocytes, intestinal production of IFN-gamma and Salmonella-induced intestinal inflammation were both significantly decreased compared with a strain deficient only in T and B cells. The authors' observations point to an important function for NK cells and NK-derived IFN-gamma in regulating the intestinal inflammatory response to Salmonella.  (+info)

Acute mesenteric lymphadenitis due to Yersinia pseudotuberculosis lacking a virulence plasmid. (7/24)

A serotype 4a strain of Yersinia pseudotuberculosis lacking the virulence plasmid pYV (pYV- strain) was isolated from the mesenteric lymph nodes but not from the stool or the appendix of a 10-year-old girl with a diagnosis of acute mesenteric lymphadenitis. Microscopically, reticulocytic abscess and lymphadenitis were persent in the enlarged mesenteric lymph nodes. Antibody against the isolate was detected in the serum. The isolate was negative for the presence of plasmid pYV and plasmid pYV-mediated properties, including autoagglutination and calcium dependency, but was positive for chromosome-mediated properties, including invasion into HeLa cells and tissues of mice and the Sereny test. Mice were orally infected with this pYV- strain, and rapid elimination from the intestine occurred 14 days later. Hence, the potential to inhibit the phagocytosis encoded by plasmid pYV was lacking. As the pYV- strain was recovered from the mesenteric lymph nodes and the spleen, the invasiveness was encoded by chromosomal genes. The count of the pYV- strain in the mesenteric lymph nodes increased to 10(4.6) cells per g within 4 days. These findings suggest that pYV- Y. pseudotuberculosis was the causative agent of acute mesenteric lymphadenitis in the absence of gastroenteritis.  (+info)

Appendicitis, mesenteric lymphadenitis, and subsequent risk of ulcerative colitis: cohort studies in Sweden and Denmark. (8/24)

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