40 research outputs found
Endoscopic Management of a Primary Duodenal Carcinoid Tumor
Carcinoids are rare, slow-growing tumors originating from a variety of different neuroendocrine cell types. They are identified histologically by their affinity for silver salts and by positive reactions to neuroendocrine markers such as neuron-specific enolase, synaptophysin and chromogranin. They can present with various clinical symptoms and are difficult to diagnose. We present the case of a 43-year-old woman who was referred for evaluation of anemia. Upper endoscopy showed a duodenal bulb mass around 1 cm in size. Histopathological and immunohistochemistry staining were consistent with the diagnosis of a carcinoid tumor. Further imaging and endoscopic studies showed no other synchronous carcinoid lesions. Endoscopic ultrasound (EUS) revealed a 1 cm lesion confined to the mucosa and no local lymphadenopathy. Successful endoscopic mucosal resection of the mass was performed. Follow-up surveillance 6 months later with EUS and Octreoscan revealed no new lesions suggestive of recurrence. No consensus guidelines exist for the endoscopic management of duodenal carcinoid tumors. However, endoscopic resection is safe and preferred for tumors measuring 1 cm or less with no evidence of invasion of the muscularis layer
Biochemical Comparison of Anopheles gambiae and Human NADPH P450 Reductases Reveals Different 2′-5′-ADP and FMN Binding Traits
NADPH-cytochrome P450 oxidoreductase (CPR) plays a central role in chemical
detoxification and insecticide resistance in Anopheles gambiae,
the major vector for malaria. Anopheles gambiae CPR (AgCPR) was
initially expressed in Eschericia coli but failed to bind
2′, 5′-ADP Sepharose. To investigate this unusual trait, we
expressed and purified a truncated histidine-tagged version for side-by-side
comparisons with human CPR. Close functional similarities were found with
respect to the steady state kinetics of cytochrome c reduction,
with rates (kcat) of 105
s−1 and 88 s−1, respectively, for mosquito
and human CPR. However, the inhibitory effects of 2′,5′-ADP on
activity were different; the IC50 value of AgCPR for 2′,
5′ –ADP was significantly higher (6–10 fold) than human CPR
(hCPR) in both phosphate and phosphate-free buffer, indicative of a decrease in
affinity for 2′, 5′- ADP. This was confirmed by isothermal titration
calorimetry where binding of 2′,5′-ADP to AgCPR
(Kd = 410±18 nM) was
∼10 fold weaker than human CPR
(Kd = 38 nM). Characterisation
of the individual AgFMN binding domain revealed much weaker binding of FMN
(Kd = 83±2.0 nM) than the equivalent
human domain (Kd = 23±0.9 nM).
Furthermore, AgCPR was an order of magnitude more sensitive than hCPR to the
reductase inhibitor diphenyliodonium chloride
(IC50 = 28 µM±2 and 361±31
µM respectively). Taken together, these results reveal unusual biochemical
differences between mosquito CPR and the human form in the binding of small
molecules that may aid the development of ‘smart’ insecticides and
synergists that selectively target mosquito CPR
Current management of the gastrointestinal complications of systemic sclerosis.
Systemic sclerosis is a multisystem autoimmune disorder that involves the gastrointestinal tract in more than 90% of patients. This involvement can extend from the mouth to the anus, with the oesophagus and anorectum most frequently affected. Gut complications result in a plethora of presentations that impair oral intake and faecal continence and, consequently, have an adverse effect on patient quality of life, resulting in referral to gastroenterologists. The cornerstones of gastrointestinal symptom management are to optimize symptom relief and monitor for complications, in particular anaemia and malabsorption. Early intervention in patients who develop these complications is critical to minimize disease progression and improve prognosis. In the future, enhanced therapeutic strategies should be developed, based on an ever-improving understanding of the intestinal pathophysiology of systemic sclerosis. This Review describes the most commonly occurring clinical scenarios of gastrointestinal involvement in patients with systemic sclerosis as they present to the gastroenterologist, with recommendations for the suggested assessment protocol and therapy in each situation
Italian Association of Clinical Endocrinologists (AME) position statement: a stepwise clinical approach to the diagnosis of gastroenteropancreatic neuroendocrine neoplasms
Multimodality treatment of neuroendocrine tumors of the thymus
Background: Neuroendocrine tumors of the thymus are rare neoplasms. Four
patients with this tumor who underwent multimodality treatment are
presented and the literature is briefly reviewed. Methods: The medical
records of all patients treated for neuroendocrine tumors of the thymus
from 1979 to 2002 were reviewed. Tumors were classified using a slight
modification of the World Health Organization criteria. Results: The
patients’ median age was 38 years. All patients underwent extensive
excision of the tumor. Histological diagnosis was atypical carcinoid
(2), typical carcinoid (1), and small cell carcinoma (1). All patients
developed recurrence(s). One patient died 132 months after diagnosis.
The remaining three patients are alive with no symptoms at 135, 99, and
35 months, respectively, after diagnosis. Two patients with recurrences
have been on treatment with Octreotide LAR (R) with satisfactory
results. One patient is free of disease. Conclusions: Neuroendocrine
tumors of the thymus are potentially aggressive tumors. Radical
resection is the treatment of choice. The encouraging results obtained
by administration of Octreotide LAR (R) in two of our patients warrant
further investigation
The effect of thymosin α1 for prevention of infection in patients with severe acute pancreatitis
Alterations of systemic endotoxemia over the course of acute edematous pancreatitis - Correlation to the advent of an infection
Background/Aims: To define whether bacterial translocation occurs over
the course of acute edematous pancreatitis and to correlate its presence
to the advent of an infection since data in humans are lacking. Methods:
Thirty-three patients hospitalized over the period January 2000-January
2001 were subjected to venipuncture at regular time intervals for the
collection of blood samples for blood culture and for determination of
endotoxins and of C-reactive protein. Endotoxins were measured by the
Limulus assay and C-reactive protein by nephelometry. Results: A wide
range of concentrations of endotoxins was observed over the first 3 days
of the disease. Mean (+/-SE) of endotoxins was 4.01 +/- 1.36 and 2.42
+/- 0.95 EU/ml 3 and 6 h, respectively, after admission of afebrile
patients. Respective values 3 and 6 h after admission of febrile
patients were 3.03 +/- 1.14 and 5.84 +/- 2.28 EU/ml (normal <0.1 EU/ml);
these values gradually decreased after the second day. No correlation
was found between endotoxins and C-reactive protein. Endotoxins were
increased as a result of the occurrence of an infection on the third
day. Conclusions: A significant level of endotoxemia is observed over
the course of acute edematous pancreatitis, which might be correlated to
the advent of the systemic inflammatory response. Copyright (C) 2003 S.
Karger AG, Basel and IAP