Solitary true cyst of the pancreas

We report a case of a woman diagnosed with a solitary true cyst of the pancreas. CT and especially MRI guided us in the diagnosis of this benign lesion. The cyst has been surgically removed because of secondary bile-duct obstruction causing painless jaundice. Clinical history, laboratory, imaging, and histological findings are reported. Received 28 May 1997; Revision received 21 December 1997; Accepted 24 December 1997     

Metastasis of transitional cell carcinoma to the lower abdominal wall 20 years after cystectomy

Iatrogenic implantation has been the main cause in the majority of cases of transitional call carcinoma (TCC) with metastasis to the abdominal wall. A 66-year-old woman had undergone radical cystectomy 20 years prior to presenting. Radiological investigations revealed one mass in the left lower abdominal wall and one mass in the right inguinal area. She underwent wide excision of the lesions that revealed metastasis of TCC. This report describes this case of a woman with bladder carcinoma who developed a metastasis in the anterior abdominal wall following an apparent disease-free interval of 20 years.     

NKT cells promote antibody-induced joint inflammation by suppressing transforming growth factor beta1 production

Although NKT cells has been known to exert protective roles in the development of autoimmune diseases, the functional roles of NKT cells in the downstream events of antibody-induced joint inflammation remain unknown. Thus, we explored the functional roles of NKT cells in antibody-induced arthritis using the K/BxN serum transfer model. NKT cell-deficient mice were resistant to the development of arthritis, and wild-type mice administrated with alpha-galactosyl ceramide, a potent NKT cell activator, aggravated arthritis. In CD1d-/- mice, transforming growth factor (TGF)-beta1 was found to be elevated in joint tissues, and the blockade of TGF-beta1 using neutralizing monoclonal antibodies restored arthritis. The administration of recombinant TGF-beta1 into C57BL/6 mice reduced joint inflammation. Moreover, the adoptive transfer of NKT cells into CD1d-/- mice restored arthritis and reduced TGF-beta1 production. In vitro assay demonstrated that interleukin (IL)-4 and interferon (IFN)-gamma were involved in suppressing TGF-beta1 production in joint cells. The adoptive transfer of NKT cells from IL-4-/- or IFN-gamma-/- mice did not reverse arthritis and TGF-beta1 production in CD1d-/- mice. In conclusion, NKT cells producing IL-4 and IFN-gamma play a role in immune complex-induced joint inflammation by regulating TGF-beta1.     

T cell expression of CIITA represses Th1 immunity

Despite the fact that major histocompatibility complex class II transactivator (CIITA) has been known to be involved in Th1/Th2 balance in addition to its major role as a master regulator for the expression of MHC class II genes, the exact role of CIITA in Th1/Th2 balance is still controversial. To investigate whether the Th1/Th2 balance could be modulated by T cell specific expression of CIITA, we generated CIITA-transgenic mice, in which the CIITA expression is controlled by the distal promoter of p56lck, resulting in constitutive expression of CIITA predominantly in peripheral T cells. Naive CD4+ T cells from CIITA-transgenic mice exhibited a low level of IFN-gamma secretion as well as impaired Th1 polarization in vitro, while IL-4 secretion was enhanced under Th2 condition. In addition, the development of experimental autoimmune encephalomyelitis (EAE), a prototype of Th1-mediated disease, was repressed in CIITA-transgenic mice. Resistance to EAE was correlated with reduced production of IFN-gamma in response to MOG35-55, while the proliferation of MOG35-55 -specific T cells was not affected in CIITA-transgenic mice. Together, these data demonstrate that overexpression of CIITA in T cells inhibits Th1 differentiation and function, suggesting that the expression of CIITA in T cells might play a role in the regulation of the Th1/Th2 balance during the T cell lineage commitment.     

Critical role for the alpha-1B adrenergic receptor at the sympathetic neuroeffector junction

The alpha-1 adrenergic receptors (alpha(1)ARs) are critical in sympathetically mediated vasoconstriction. The specific role of each alpha(1)AR subtype in regulating vasoconstriction remains highly controversial. Limited pharmacological studies suggest that differential alpha(1)AR responses may be the result of differential activation of junctional versus extrajunctional receptors. We tested the hypothesis that the alpha(1B)AR subtype is critical in mediating sympathetic junctional neurotransmission. We measured in vivo integrated cardiovascular responses to a hypotensive stimulus (induced via transient bilateral carotid occlusion [TBCO]) in alpha(1B)AR knockout (KO) mice and their wild-type (WT) littermates. In WT mice, after dissection of the carotid arteries and denervation of aortic baroreceptor buffering nerves, TBCO produced significant pressor and positive inotropic effects. Both responses were markedly attenuated in alpha(1B)AR KO mice (change systolic blood pressure 46+/-8 versus 11+/-2 mm Hg; percentage change in the end-systolic pressure-volume relationship [ESPVR] 36+/-7% versus 12+/-2%; WT versus KO; P<0.003). In vitro alpha(1)AR mesenteric microvascular contractile responses to endogenous norepinephrine (NE; elicited by electrical field stimulation 10 Hz) was markedly depressed in alpha(1B)AR KO mice compared with WT (12.4+/-1.7% versus 21.5+/-1.2%; P<0.001). In contrast, responses to exogenous NE were similar in alpha(1B)AR KO and WT mice (22.4+/-7.3% versus 33.4+/-4.3%; NS). Collectively, these results demonstrate a critical role for the alpha(1B)AR in baroreceptor-mediated adrenergic signaling at the vascular neuroeffector junction. Moreover, alpha(1B)ARs modulate inotropic responses to baroreceptor activation. The critical role for alpha(1B)AR in neuroeffector regulation of vascular tone and myocardial contractility has profound clinical implications for designing therapies for orthostatic intolerance.     

Adult intussusception: experience in Singapore

Introduction: Gastrointestinal intussusception is an uncommon clinical entity in adults and is interestingly distinct from its paediatric form. In adults an identifiable lead lesion is found in the majority of cases, of which a significant percentage are malignant. Its treatment is thus different from that of paediatric intussusception. The present study reviews our experience of treating adult intussusception. Methods: A retrospective review of patients with a postoperative diagnosis of gastrointestinal intussusception between January 1997 and December 2002 was conducted. All patients under the age of 18 and cases of rectal prolapse were excluded. Results: During the 5‐year period, there were nine cases of intussusception. There were four male and five female patients, with a mean age of 63.8 years (range 37?85 years). Less than half of the patients (44.4%) presented with acute symptoms. The most common symptoms were abdominal pain and distension. The symptoms were intermittent in 77.8% (7 of 9) of patients. Only two patients had a palpable abdominal mass, while another had signs of acute intestinal obstruction. Computed tomography was the most useful imaging modality, identifying intussusception in six out of six patients. Eight patients had lead lesions occurring at the ileocaecal junction resulting in ileo‐colonic intussusception. Of these eight, four were malignant (two adenocarcinomas and two lymphomas). There was one sigmoid‐rectal intussusception secondary to adenocarcinoma. All patients were treated operatively. Seven patients were treated with en bloc resection. Conclusion: Although uncommon, surgeons need to be aware of the epidemiology and treatment options for adult intussusception. The symptoms and signs are often non‐specific and the surgeon might be faced with the diagnosis only at laparotomy. Computed tomography is the most useful imaging modality. An identifiable organic lesion is present in most cases, of which more than 50% are malignant (especially in the large bowel). Operative treatment is thus prudent. En bloc resection is recommended for ileo‐colonic and colo‐colonic intussusception. There is, however, a role of initial reduction in selected patients with ileo‐ileal intussusception.     

Is myo‐inositol a measure of glial swelling after stroke? a magnetic resonance study

PURPOSE: To determine whether the hypothesis that the phenomenon of persistent cytotoxic edema in the subacute stage of ischemic stroke is in fact associated with the glial population. This is done by assessing the evolution of both the apparent diffusion coefficient (ADC) and the glial-specific marker myo-inositol (Ins) in a group of patients, and by comparing the results with the total cellular density by means of the creatine (Cre) level. MATERIAL AND METHODS: Twenty-two patients with stroke in the territory of the middle cerebral artery were each examined once only at a time ranging from eight hours to six days following the onset of symptoms. Lesion-to-contralateral values of ADC were obtained based on diffusion-weighted echo-planar imaging. Short TE single-voxel proton magnetic resonance ((1)H MR) spectroscopy was used for quantification of cerebral metabolites in infarcted regions. Their levels were also compared with those in homotopic contralateral regions. RESULTS: In the stroke lesion, there was a significant correlation between ADC and the Ins level, albeit less pronounced than that for Cre. During different pathophysiological stages between 12 hours and three days, the Ins-to-Cre ratio increased by a factor of two and returned to apparently normal thereafter. CONCLUSION: Our study provides the first demonstration of a relationship between persistent cytotoxic edema and the glial population in the context of cell swelling due to osmotic imbalance in stroke patients.     

Evolutionary origin and emergence of a highly successful clone of serotype M1 group a Streptococcus involved multiple horizontal gene transfer events

To better understand the molecular events involved in the origin of new pathogenic bacteria, we studied the evolution of a highly virulent clone of serotype M1 group A Streptococcus (GAS). Genomic, DNA-DNA microarray, and single-nucleotide polymorphism analyses indicated that this clone evolved through a series of horizontal gene transfer events that involved (1) the acquisition of prophages encoding streptococcal pyrogenic exotoxin A and extracellular DNases and (2) the reciprocal recombination of a 36-kb chromosomal region encoding the extracellular toxins NAD+-glycohydrolase (NADase) and streptolysin O (SLO). These gene transfer events were associated with significantly increased production of SLO and NADase. Virtual identity in the 36-kb region present in contemporary serotype M1 and M12 isolates suggests that a serotype M12 strain served as the donor of this region. Multiple horizontal gene transfer events were a crucial factor in the evolutionary origin and emergence of a very abundant contemporary clone of serotype M1 GAS.     

Effect of low adapted temperature and medium composition on growth and erythropoietin (EPO) production by Chinese hamster ovary cells

Temperature and medium composition were changed with the aim of increasing growth and erythropoietin (EPO) production in EPO-producing Chinese hamster ovary (CHO) cells. We used the CHO cell line, IBE, and its derivative, CO5, which over-expresses the first two enzymes of the urea cycle, carbamoyl phosphate synthetase I (CPS I) and ornithine transcarbamoylase (OTC). When supplements were added to the medium at 33 degrees C, the growth of IBE and CO5 cells increased by 27% and 26%, respectively and the maximum yield of EPO was increased by 40% in both cell lines. The absolute EPO concentration in the CO5 cells was always 55-60% higher than in the IBE cells. In addition, when the two cell lines were continuously cultured with supplements at 33 degrees C until their growth rates approached those at 37 degrees C, the growth rates of both IBE and CO5 cells increased by 54% and their maximum EPO levels increased by up to 73% and 56%, respectively. Therefore, the growth and EPO expression levels of CO5 cells increased 2.2-fold and 2.6-fold, respectively, compared to those of the IBE cells. These results indicate that adaptation to lower temperature as well as medium supplementation could be important for improving cell growth and EPO production.