Gastric blood flow

Summary In summary, the vascular bed of the stomach is an area of great potential importance to both gastric and vascular physiologists. There are available many technics for its investigation. Simultaneous study of both hemodynamic and secretory phenomena can be conducted on the stomach. In the next few years information concerning the circulation of the stomach may help elucidate problems in the physiology and pathology of gastric secretion. Hightower observed recently: The topic of visceral circulation, particularly as it pertains to the digestive tract, has not been commented upon in recent...Reviews of Physiology. This subject has become increasingly important in the past few years and is an area with which physiologists interested in the digestive system will become more and more concerned.³³     

Exchange transfusion in the treatment of patients with acute hepatitis in coma

Summary Acute hepatic necrosis with profound coma carries an ominous prognosis. Conventional therapy has had little influence on recovery. Various new therapeutic modalities are currently being tried. Survival figures derived by compiling reports on exchange transfusion are somewhat encouraging when the data are compared to the salvage rate in patients with fulminant hepatitis treated conventionally, even after the addition of steroids. Current knowledge is lacking as to the specific lethal factor (s) and/or mechanism (s) that are operating in these patients. Pathogenetic ignorance notwithstanding, the remarkable regenerative power of the liver dictates that all efforts be made to sustain life, as the therapist hopefully awaits recovery. If facilities and personnel are available, we feel exchange transfusion should be considered when 24 hr of intensive conventional therapy, including high doses of steroids, fails to bring about significant improvement. Any decision on duration of therapy in the absence of neurologic improvement remains arbitrary. Histologic evidence of liver cell regeneration, if it can be obtained, may justify continued therapeutic efforts. Exchange transfusion must be evaluated by a cooperative controlled study before its therapeutic value can be established.     

Cabergoline Therapy of Growth Hormone & Growth Hormone/Prolactin Secreting Pituitary Tumors

Dopamine agonists have been used as adjunctive therapy for acromegaly for many years, but relatively few studies have assessed the efficacy of a newer agonist, cabergoline. Some data suggest that cabergoline may be more effective than bromocriptine, in particular for those patients whose tumors secrete both growth hormone and prolactin. In order to assess this possibility further, we have evaluated the biochemical response to cabergoline therapy in patients with acromegaly at our center. We describe first an unusual patient who presented with a pituitary macroadenoma secreting both GH and prolactin. At presentation he had elevated levels of growth hormone 6.0 microg/L, IGF-I, 722 ng/ml, and prolactin, 6000 ng/ml. Cabergoline therapy alone was highly effective in this patient and normalized his levels of all three hormones and his gonadal function as well as produced significant shrinkage of his pituitary tumor. Fourteen other patients with more typical, active postoperative acromegaly were administered cabergoline in a 6-month, open label, dose-escalation study. Mean baseline GH was 1.3 +/- .23 ng/ml and fell to a nadir of 0.85 +/- .18 ng/ml on cabergoline therapy (p = 0.03). Mean baseline IGF-I was 520 +/- 45.2 ng/ml and fell to a mean nadir during cabergoline therapy of 368 +/- 29.8 ng/ml (p = 0.0013). At the completion of the cabergoline therapy study period, however, mean IGF-I was 453 +/- 46 ng/ml, not significantly lower than the baseline value (p = 0.11). No changes in tumor sizes occurred on cabergoline therapy. Eight of 14 patients achieved a normal IGF-I at some point during the 24 weeks study period, but the efficacy of cabergoline waned with time as only 3 of 14 (21%) of patients had a persistently normal IGF-I with up to 18 months of cabergoline therapy. Six patients had modest hyperprolactinemia at diagnosis (26-142 ng/ml) and 5 patients had positive immunohistochemical staining of their tumor for prolactin, but in neither of these small groups was cabergoline therapy more effective at normalizing IGF-I than in those patients with apparently pure GH secreting tumors. Three of 14 patients (21%) had side effects that limited therapy. A trial of cabergoline as adjunctive therapy may be considered in select patients with mild disease and small tumor residuals, but the expectation for biochemical control in these patients needs to be kept low, even for tumors that co-secrete GH and prolactin.     

Isolated polyarteritis nodosa affecting the cecum

Summary We report the case of a 52-year-old white male who developed low back pain and 35-pound weight loss and whose barium enema revealed a constricting lesion of the cecum. After resection, polyarteritis was found to be the cause of the lesion. There was no other histological evidence for arteritis in this patient.The opinions expressed herein are those of the authors and not necessarily those of the Department of Defense, U.S. Air Force, or the Uniformed Services University of the Health Sciences.Figures are published with permission from the Armed Forces Institute of Pathology.     

Nonoperative management of delayed splenic rupture in an adult

Due to the evidence that a splenectomized patient is at increased risk for serious infection, nonoperative management of splenic injury, as well as operations designed to preserve functioning splenic tissue, have been recently reported. Most experience in nonoperative management has been in the pediatric and young-adult age groups. We report a case of delayed rupture of the spleen in a middle-aged patient who was successfully managed nonoperatively and was followed with ultrasonography to resolution.Supported in part by the Bureau of Medicine and Surgery Clinical Investigation Program.     

Glycosylation of surface Ig creates a functional bridge between human follicular lymphoma and microenvironmental lectins

Surface Ig (sIg) of follicular lymphoma (FL) is vital for tumor cell survival. We found previously that the Ig in FL is unusual, because the variable region genes carry sequence motifs for N-glycan addition. These are introduced by somatic mutation and are tumor specific. Unexpectedly, added glycans terminate at high mannose, suggesting a potentially important interaction of FL cells with mannose-binding lectins of the innate immune system. We have now identified mannosylated IgM at the surface of primary lymphoma cells. Recombinant lectin domains of the mannose receptor (MR) or DC-SIGN bind mannosylated Igs in vitro and bind to FL cells, signaling sIgM-associated increases in intracellular Ca(2+). Lectins also bind to normal B cells but fail to signal. In contrast, anti-Ig signaled similarly in both FL and normal B cells. Mannosylation patterns were mimicked by FL Ig-derived single-chain Fvs (scFv), providing probes for potential receptors. Mannosylated scFv bound specifically to the lectin domains of the MR and DC-SIGN and blocked signaling. Mannosylated scFv also bound to DC-SIGN on the surface of dendritic cells. This unique lymphoma-specific interaction of sIg with lectins of innate immunity reveals a potential route for microenvironmental support of tumor cells, mediated via the key B-cell receptor.