Esophagogastric decompression and enteral feeding following cholecystectomy: a controlled, randomized prospective trial

One hundred fourteen patients scheduled to undergo elective cholecystectomy were prospectively randomized into one of four treatment groups to study the potential benefits of esophagogastric decompression with and without immediate postoperative enteral nutrition. Group I was the control, and patients received only iv fluids and were allowed to eat as tolerated. Group II patients received iv fluids and esophagogastric decompression. Group III patients received esophagogastric decompression and enteral sterile water through the duodenal feeding lumen. Group IV patients received esophagogastric decompression and infusion of an elemental diet through the feeding lumen. The surgical techniques were standardized for all patients. The results of the study indicated no statistically or clinically significant differences among any of the treatment groups regarding; (1) need for parenteral analgesics or antiemetics, (2) tolerance of regular diet, (3) postoperative day of discharge, and (4) postoperative day that other discharge criteria were met. It is concluded that there is no objective benefit to the routine use of esophagogastric decompression with or without enteral nutrition in elective cholecystectomy patients.     

Functional changes in canine saphenous veins after cryopreservation.

This study was designed to determine the functional characteristics of the endothelium, smooth muscle and nerve terminals of cryopreserved veins. Freshly harvested and cryopreserved canine saphenous veins were cut into rings. In some rings, the endothelium was removed. Cryopreserved veins were stored at -196 degrees C for at least 3 weeks prior to use. All rings contracted in a concentration-dependent manner to depolarization with KCl and to alpha-adrenergic stimulation; the maximal tensions were significantly less in cryopreserved than in freshly harvested veins. Calcium ionophore A23187 caused greater relaxations in rings with than without endothelium in freshly harvested and cryopreserved veins. These relaxations were reduced significantly by methylene blue and NG-monomethyl-L-arginine (L-NMMA) only in fresh veins. Cocaine-sensitive uptake of H3-norepinephrine was reduced following cryopreservation. Immediately after cryopreservation, the production of prostacyclin was elevated. The calcium ionophore A23187 stimulated production of prostacyclin only in freshly harvested veins. Tissue content of endothelin did not change following cryopreservation. These results suggest that cryopreservation of canine saphenous veins alters nerve terminals and decreases the ability of the smooth muscle to contract. The endothelium releases an endothelium-derived relaxing factor and prostanoids following cryopreservation but the ability to synthesize nitric oxide is probably reduced. These changes following cryopreservation may affect patency of the veins when used as arterial grafts.     

Priming of the oxidative burst in human neutrophils by physiological agonists or cytochalasin B results from the recruitment of previously non-responsive cells.

Using a sensitive flow cytometric assay, which measures the intracellular oxidation of 2'7' dichlorofluorescein (DCFH) by H2O2, we have assessed, at a single-cell level, the effects of a variety of physiological priming agonists and cytochalasin B (CB) on purified populations of neutrophils stimulated at different points along the signal response transduction pathway. Pretreatment of purified neutrophils with the physiological priming agonists monocyte interleukin-8 (IL-8), granulocyte-monocyte colony-stimulating factor (GM-CSF), platelet-activating factor (PAF), IL-1 beta, tumour necrosis factor-alpha (TNF-alpha), IL-6, and non-stimulatory doses of formyl-methionyl-leucyl-phenylalanine (FMLP), resulted in an increased percentage of cells generating an oxidative burst in response to subsequent receptor stimulation with FMLP. CB had a similar but much more pronounced effect on cellular recruitment to a receptor-mediated responsive state. Activation of protein kinase C (PKC) using the phorbol ester phorbol myristate acetate (PMA) resulted in a heterogeneous response, with all cells generating H2O2, but with two populations differing in their magnitude of response. Physiological priming agonists had no effect on the heterogeneity of the PMA response. However, pretreatment with CB dramatically altered the PMA response, producing a homogeneous population highly responsive to stimulation with PKC. In contrast, direct stimulation of G proteins with fluoride (A1F-4) was primed both by physiological priming agonists and by CB. These results demonstrate that priming of neutrophils by physiological agonists involves changes at the level of signal transduction which enable a previously non-responsive cell to respond to a secondary stimulus.(ABSTRACT TRUNCATED AT 250 WORDS)     

Meal patterns of normal, untreated bulimia nervosa and recovered bulimic women

In order to examine the meal pattern characteristics associated with bulimia nervosa the meal patterns of 19 untreated bulimia nervosa, 12 recovered bulimics, and 21 normal controls spontaneously eating in their natural environments were compared. Subjects reported in a diary everything they either ate or drank for seven consecutive days. Meal pattern correlations included comparisons of the groups in regard to meal size (and binge size), meal frequency, premeal and postmeal intervals, deprivation ratios, satiety ratios, stomach contents, and composition of meals and binges. Results indicated that, although total reported intake was normal, only 33% of the total calories consumed by the untreated bulimia nervosa subjects were not followed immediately by purging. Both purged and unpurged binges were twice as large as their meal sizes which did not differ from normal. It is hypothesized that the caloric restriction of the untreated bulimics is binge/purge specific, and is used by them as a form of weight control. The recovered group showed a lack of responsivity to the signals that influence meal size and intermeal intervals in normals including impaired social facilitation of eating. They also had larger meal sizes, and greater frequency of meals. It is theorized that recovered bulimics employ other, as yet unspecified, means of food intake restriction resulting in an abnormal feeding pattern.     

The A427 anchorage-independence assay as a screening tool to identify potential chemopreventive agents

An in vitro model for screening potential chemopreventive agents using inhibition of anchorage-independent growth of a human lung tumor cell line, A427, is described. A427 cells were selected for the model development, as they are known to be tumorigenic in animals, can grow in soft agarose, and their growth can be inhibited by a well-known chemopreventive agent, 13-cis-retinoic acid. Cells are plated on agarose, allowed to develop colonies for 28 days, the stained colonies are enumerated, and the inhibition of spontaneous colony formation measured. A cytotoxicity test is used concurrently with anchorage independent assay for measuring the relative survival of cells to ensure that any observed inhibition of anchorage independent growth is due to the biological activity of the chemopreventive agents, as it uses human cells as substrates rendering the efficacy data feasible for direct extrapolation to humans.     

Epstein-Barr viral load as a marker of lymphoma in AIDS patients

Epstein-Barr virus (EBV) is implicated in the pathogenesis of acquired immunodeficiency syndrome (AIDS) lymphoma, and viral DNA is present within the malignant cells in about half of affected patients. We examined the extent to which EBV viral load is elevated in the plasma of AIDS lymphoma patients compared to AIDS patients with opportunistic infections. Sixty-one AIDS patients were studied including 35 with lymphoma (24 non-Hodgkin, six Hodgkin, and five brain lymphoma) and 26 with various opportunistic infections. In situ hybridization revealed EBV encoded RNA (EBER) expression in the malignant cells of 17/28 AIDS lymphomas (61%). In 232 serial plasma samples from 35 lymphoma patients and in 128 samples from AIDS controls, EBV viral load was assayed by quantitative-polymerase chain reaction (Q-PCR) using a TaqMan probe targeting the BamH1W sequence. EBV was detected in plasma from all 17 EBER-positive AIDS lymphoma patients, with viral loads ranging from 34 to 1,500,000 copies per ml (median 3,210). Viral load usually fell rapidly upon initiation of lymphoma therapy and remained undetectable except in two patients with persistent tumor. In 11 AIDS patients, whose lymphoma lacked EBER expression, and in 26 control patients without lymphoma, levels of EBV in plasma were usually low or undetectable (range 0-1,995 and 0-2,409, median 0 and 0, respectively). There was no association between EBV viral load and human immunodeficiency virus (HIV) load or CD4 count. In conclusion, EBV viral load shows promise as a tool to assist in diagnosis and management of EBV-related lymphoma patients.     

Use of limited color-flow duplex for a carotid screening project.

BACKGROUND: Although the efficacy of carotid endarterectomy for asymptomatic carotid stenosis has been established, no cost-effective approach for identification of these patients has yet been devised. The purpose of this study was to develop a limited carotid duplex screening examination to be utilized for the detection of asymptomatic carotid stenoses. METHODS: Carotid screening examinations employed rapid identification of the carotid bifurcation using color-flow duplex imaging and an immediate Doppler-derived velocity of the segment of the internal carotid artery with the most turbulent flow. Complete examinations were then finished using well-established protocols in our accredited vascular laboratory. A total of 512 patients were referred for complete studies based upon standard indications. Criteria for at least a 50% internal carotid artery stenosis on the complete examination was defined as a peak systolic velocity (PSV) of at least 125 cm/sec. Receiver operator characteristic (ROC) curves were then constructed to identify the optimal screening velocity criteria as compared with the final results on the complete examination. RESULTS: Five screening examinations were technically limited yielding a total of 507 patients with 1,014 carotid arteries available for analysis. Comparison of screening examinations versus complete examinations for a PSV of 125 cm/sec yielded sensitivity 86%, specificity 98%, positive predictive value (PPV) 95%, and a negative predictive value (NPV) 93%. ROC analysis identified a "cut point" of 115 cm/sec on the screening examinations to achieve sensitivity 91%, specificity 95%, PPV 89%, and NPV 96%. Time to perform screening examinations averaged 3.2 minutes per patient. Three patients had common carotid lesions not identified on the limited internal carotid screening examinations. CONCLUSIONS: Screening carotid examinations are a rapid, reliable, and relatively inexpensive method for detection of patients with asymptomatic internal carotid artery stenosis. Limited screening examinations should be developed in each vascular laboratory and utilized in high-risk patients.