Cavitating mesenteric lymph node syndrome in association with coeliac disease and enteropathy associated T-cell lymphoma: a case report and review of the literature.

Cavitating mesenteric lymph node syndrome (CMLNS) is a rare and poorly understood complication of coeliac disease (CD), with only 37 cases reported in the literature. CD is an immune-mediated enteropathy, with alterations seen in the small bowel architecture on exposure to ingested gluten. Those who fail to respond to a strict gluten-free diet are termed to have refractory coeliac disease (RCD). This is associated with serious complications such as enteropathy-associated T-cell lymphoma (EATL). We present the case of a 71-year-old female investigated for weight loss and a palpable intraabdominal mass. Abdominal computed tomographic (CT) scan showed multiple necrotic mesenteric lymph nodes. At operation, multiple cavitating mesenteric lymph nodes, containing milky fluid, were found. An incidental EATL was found at the terminal ileum, which was resected. The patient subsequently tested positive for CD. This is the second case report to document an association between CMLNS and EATL. This paper highlights the varied presentation of CD. In this case, the diagnosis of CD was made retrospectively after the complications were dealt with. This paper is followed by a review of relevant literature.

Ketohexokinase: expression and localization of the principal fructose-metabolizing enzyme.

Ketohexokinase (KHK, also known as fructokinase) initiates the pathway through which most dietary fructose is metabolized. Very little is known about the cellular localization of this enzyme. Alternatively spliced KHK-C and KHK-A mRNAs are known, but the existence of the KHK-A protein isoform has not been demonstrated in vivo. Using antibodies to KHK for immunohistochemistry and Western blotting of rodent tissues, including those from mouse knockouts, coupled with RT-PCR assays, we determined the distribution of the splice variants. The highly expressed KHK-C isoform localized to hepatocytes in the liver and to the straight segment of the proximal renal tubule. In both tissues, cytoplasmic and nuclear staining was observed. The KHK-A mRNA isoform was observed exclusively in a range of other tissues, and by Western blotting, the presence of endogenous immunoreactive KHK-A protein was shown for the first time, proving that the KHK-A mRNA is translated into KHK-A protein in vivo, and supporting the suggestion that this evolutionarily conserved isoform is physiologically functional. However, the low levels of KHK-A expression prevented its immunohistochemical localization within these tissues. Our results highlight that the use of in vivo biological controls (tissues from knockout animals) is required to distinguish genuine KHK immunoreactivity from experimental artifact.

Ileitis in ulcerative colitis: is it a backwash?

PURPOSE: This study aims to determine the incidence, demography, pathologic nature, and clinical significance of ileitis in ulcerative colitis patients who underwent restorative proctocolectomy. METHODS: A prospectively collected pouch database and the case notes of 100 consecutive patients who underwent restorative proctocolectomy for ulcerative colitis, under the care of a single surgeon, between 1988 and 2003 were reviewed. The original proctocolectomy specimens and pouch biopsies were reexamined and regraded blind, using the current diagnostic criteria. Patients were divided into two groups, those who had ileitis and those who had not. The demographic, clinical, and pathologic characteristics and the incidence of pouchitis of both groups were compared. RESULTS: Twenty-two patients had ileitis (22 percent). Compared with those with noninflamed ileum, patients with ileitis had a significantly shorter disease duration (P < 0.005), many of them presented or progressed to a fulminant state requiring acute surgical intervention (P < 0.01), had strong association with pancolitis and primary sclerosing cholangitis (P < 0.001), and had a higher incidence of subsequent development of pouchitis (P < 0.001). There was no correlation between the presence of ileitis and colitis severity. CONCLUSIONS: Ileitis in ulcerative colitis is not rare and does influence the prognosis, and the term "backw ash" is a misnomer. Ulcerative colitis with ileitis represents a distinct disease-specific subset of patients. Its true incidence and clinical significance can be determined only if detailed microscopic characterization of the terminal ileum is performed routinely in every patient with ulcerative colitis and the clinical outcome of these patients is audited prospectively.

Dysregulation of apoptosis in Waldenstrom's macroglobulinemia does not involve nuclear factor kappa B activation.

Indolent lymphoproliferative disorders such as Waldenstrom's macroglobulinemia (WM) are characterized by defective apoptosis, which leads to progressive accumulation of slowly dividing neoplastic lymphocytes. Activation of nuclear factor kappa B (NFkappaB) is considered to have a central pathogenic role in some hematological malignancies, including multiple myeloma, Hodgkin's disease, and extranodal marginal zone lymphoma (ENMZL). NFkappaB activation may inhibit apoptosis through the transactivation of genes such as Bcl-2 and may therefore be an important mechanism in indolent lymphoproliferative disorders, including WM. In order to assess this potential mechanism, we used immunohistochemistry to determine the presence and subcellular localisation of the major NFkappaB subunits p50 and p65. Nuclear staining of NFkappaB subunits (indicative of activation) was not seen in any of the 40 cases examined. Thirty-seven (95%) cases showed cytoplasmic positivity for both p50 and p65 and one case demonstrated cytoplasmic staining for p65 alone, while the two remaining cases showed complete absence of staining. We would therefore conclude that NFkappaB activation is not a feature of WM and that alternative mechanisms of apoptosis inhibition should be investigated in this disorder.